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0a845e0f |
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04-Mar-2024 |
Peter Xu <peterx@redhat.com> |
mm/treewide: replace pud_large() with pud_leaf() pud_large() is always defined as pud_leaf(). Merge their usages. Chose pud_leaf() because pud_leaf() is a global API, while pud_large() is not. Link: https://lkml.kernel.org/r/20240305043750.93762-9-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Muchun Song <muchun.song@linux.dev> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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#
2f709f7b |
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04-Mar-2024 |
Peter Xu <peterx@redhat.com> |
mm/treewide: replace pmd_large() with pmd_leaf() pmd_large() is always defined as pmd_leaf(). Merge their usages. Chose pmd_leaf() because pmd_leaf() is a global API, while pmd_large() is not. Link: https://lkml.kernel.org/r/20240305043750.93762-8-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Muchun Song <muchun.song@linux.dev> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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#
1a65b73a |
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08-Jan-2024 |
Sumanth Korikkar <sumanthk@linux.ibm.com> |
s390/mm: allocate vmemmap pages from self-contained memory range Allocate memory map (struct pages array) from the hotplugged memory range, rather than using system memory. The change addresses the issue where standby memory, when configured to be much larger than online memory, could potentially lead to ipl failure due to memory map allocation from online memory. For example, 16MB of memory map allocation is needed for a memory block size of 1GB and when standby memory is configured much larger than online memory, this could lead to ipl failure. To address this issue, the solution involves introducing "memmap on memory" using the vmem_altmap structure on s390. Architectures that want to implement it should pass the altmap to the vmemmap_populate() function and its associated callchain. This enhancement is discussed in commit 4b94ffdc4163 ("x86, mm: introduce vmem_altmap to augment vmemmap_populate()") Provide "memmap on memory" support for s390 by passing the altmap in vmemmap_populate() and its callchain. The allocation path is described as follows: * When altmap is NULL in vmemmap_populate(), memory map allocation occurs using the existing vmemmap_alloc_block_buf(). * When altmap is not NULL in vmemmap_populate(), memory map allocation still uses vmemmap_alloc_block_buf(), but this function internally calls altmap_alloc_block_buf(). For deallocation, the process is outlined as follows: * When altmap is NULL in vmemmap_free(), memory map deallocation happens through free_pages(). * When altmap is not NULL in vmemmap_free(), memory map deallocation occurs via vmem_altmap_free(). While memory map allocation is primarily handled through the self-contained memory map range, there might still be a small amount of system memory allocation required for vmemmap pagetables. To mitigate this impact, this feature will be limited to machines with EDAT1 support. Link: https://lkml.kernel.org/r/20240108132747.3238763-3-sumanthk@linux.ibm.com Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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#
a51324c4 |
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27-Oct-2023 |
Heiko Carstens <hca@linux.ibm.com> |
s390/cmma: rework no-dat handling Rework the way physical pages are set no-dat / dat: The old way is: - Rely on that all pages are initially marked "dat" - Allocate page tables for the kernel mapping - Enable dat - Walk the whole kernel mapping and set PG_arch_1 bit in all struct pages that belong to pages of kernel page tables - Walk all struct pages and test and clear the PG_arch_1 bit. If the bit is not set, set the page state to no-dat - For all subsequent page table allocations, set the page state to dat (remove the no-dat state) on allocation time Change this rather complex logic to a simpler approach: - Set the whole physical memory (all pages) to "no-dat" - Explicitly set those page table pages to "dat" which are part of the kernel image (e.g. swapper_pg_dir) - For all subsequent page table allocations, set the page state to dat (remove the no-dat state) on allocation time In result the code is simpler, and this also allows to get rid of one odd usage of the PG_arch_1 bit. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
65d37f16 |
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27-Oct-2023 |
Heiko Carstens <hca@linux.ibm.com> |
s390/cmma: move arch_set_page_dat() to header file In order to be usable for early boot code move the simple arch_set_page_dat() function to header file, and add its counter-part arch_set_page_nodat(). Also change the parameters, and the function name slightly. This is required since there aren't any struct pages available in early boot code, and renaming of functions is done to make sure that all users are converted to the new API. Instead of a pointer to a struct page a virtual address is passed, and instead of an order the number of pages for which the page state needs be set. Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
09cda0a4 |
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17-Oct-2023 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm: add missing arch_set_page_dat() call to vmem_crst_alloc() If the cmma no-dat feature is available all pages that are not used for dynamic address translation are marked as "no-dat" with the ESSA instruction. This information is visible to the hypervisor, so that the hypervisor can optimize purging of guest TLB entries. This also means that pages which are used for dynamic address translation must not be marked as "no-dat", since the hypervisor may then incorrectly not purge guest TLB entries. Region and segment tables allocated via vmem_crst_alloc() are incorrectly marked as "no-dat", as soon as slab_is_available() returns true. Such tables are allocated e.g. when kernel page tables are split, memory is hotplugged, or a DCSS segment is loaded. Fix this by adding the missing arch_set_page_dat() call. Cc: <stable@vger.kernel.org> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
4f62c6e3 |
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15-Oct-2023 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm: make vmemmap_free() only for CONFIG_MEMORY_HOTPLUG available Get rid of this W=1 compile warning: arch/s390/mm/vmem.c:502:6: warning: no previous prototype for ‘vmemmap_free’ [-Wmissing-prototypes] 502 | void vmemmap_free(unsigned long start, unsigned long end, | ^~~~~~~~~~~~ Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
99441a38 |
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11-Sep-2023 |
Heiko Carstens <hca@linux.ibm.com> |
s390: use control register bit defines Use control register bit defines instead of plain numbers where possible. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
8d5e98f8 |
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11-Sep-2023 |
Heiko Carstens <hca@linux.ibm.com> |
s390/ctlreg: add local and system prefix to some functions Add local and system prefix to some functions to clarify they change control register contents on either the local CPU or the on all CPUs. This results in the following API: Two defines which load and save multiple control registers. The defines correlate with the following C prototypes: void __local_ctl_load(unsigned long *, unsigned int cr_low, unsigned int cr_high); void __local_ctl_store(unsigned long *, unsigned int cr_low, unsigned int cr_high); Two functions which locally set or clear one bit for a specified control register: void local_ctl_set_bit(unsigned int cr, unsigned int bit); void local_ctl_clear_bit(unsigned int cr, unsigned int bit); Two functions which set or clear one bit for a specified control register on all CPUs: void system_ctl_set_bit(unsigned int cr, unsigned int bit); void system_ctl_clear_bit(unsigend int cr, unsigned int bit); Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
ebe1cd53 |
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11-Sep-2023 |
Heiko Carstens <hca@linux.ibm.com> |
s390/ctlreg: rename ctl_reg.h to ctlreg.h Rename ctl_reg.h to ctlreg.h so it matches not only ctlreg.c but also other control register related function, union, and structure names, which all come with a ctlreg prefix. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
0c4d01f3 |
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11-Sep-2023 |
Heiko Carstens <hca@linux.ibm.com> |
s390/ctlreg: move control register code to separate file Control register handling has nothing to do with low level SMP code. Move it to a separate file. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
06fc3b0d |
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01-Sep-2023 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/vmem: do not silently ignore mapping limit The only interface that allows drivers establishing liner mappings is vmem_add_mapping(). It does check a requested range against allowed limits and a call to modify_pagetable() with an invalid mapping range is impossible. Hence, an attempt to map an address range outside of the identity mapping or vmemmap array could only be kernel bug. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
a7eb2880 |
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25-Aug-2023 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm: use __set_memory() variants where useful Use the __set_memory_yy() variants instead of set_memory_yy() where useful. This allows to make the code a bit more readable. This also fixes the debug pagealloc case, where set_memory_4k() might be called for an area larger than 8TB which would lead to an overflow of the num_pages parameter of set_memory_4k(). However RELOC_HIDE() has to be used for the __set_memory_4k() case for the time being, to avoid compiler warnings because of performing pointer arithmetic on a NULL pointer, which has undefined behavior. This happens because __va(0) always translates to NULL. However this will change, and as soon as this happens the RELOC_HIDE() hack can be removed again. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
a6e49f10 |
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25-Aug-2023 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm: improve description of mapping permissions of prefix pages Slightly improve the description which explains why the first prefix page must be mapped executable when the BEAR-enhancement facility is not installed. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
3eeb0778 |
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25-Aug-2023 |
Heiko Carstens <hca@linux.ibm.com> |
s390/amode31: change type of __samode31, __eamode31, etc For consistencs reasons change the type of __samode31, __eamode31, __stext_amode31, and __etext_amode31 to a char pointer so they (nearly) match the type of all other sections. This allows for code simplifications with follow-on patches. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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c0f1d478 |
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25-Aug-2023 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm: simplify kernel mapping setup The kernel mapping is setup in two stages: in the decompressor map all pages with RWX permissions, and within the kernel change all mappings to their final permissions, where most of the mappings are changed from RWX to RWNX. Change this and map all pages RWNX from the beginning, however without enabling noexec via control register modification. This means that effectively all pages are used with RWX permissions like before. When the final permissions have been applied to the kernel mapping enable noexec via control register modification. This allows to remove quite a bit of non-obvious code. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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7b03942f |
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03-Aug-2023 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/vmem: fix virtual vs physical address confusion Fix virtual vs physical address confusion (which currently are the same). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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2d1494fb |
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12-Aug-2023 |
Linus Walleij <linus.walleij@linaro.org> |
s390/mm: make virt_to_pfn() a static inline Making virt_to_pfn() a static inline taking a strongly typed (const void *) makes the contract of a passing a pointer of that type to the function explicit and exposes any misuse of the macro virt_to_pfn() acting polymorphic and accepting many types such as (void *), (unitptr_t) or (unsigned long) as arguments without warnings. For symmetry do the same with pfn_to_virt() reflecting the current layout in asm-generic/page.h. Doing this reveals a number of offenders in the arch code and the S390-specific drivers, so just bite the bullet and fix up all of those as well. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Link: https://lore.kernel.org/r/20230812-virt-to-phys-s390-v2-1-6c40f31fe36f@linaro.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
94fd5220 |
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02-Jul-2023 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/mm: rework arch_get_mappable_range() callback As per description in mm/memory_hotplug.c platforms should define arch_get_mappable_range() that provides maximum possible addressable physical memory range for which the linear mapping could be created. The current implementation uses VMEM_MAX_PHYS macro as the maximum mappable physical address and it is simply a cast to vmemmap. Since the address is in physical address space the natural upper limit of MAX_PHYSMEM_BITS is honoured: vmemmap_start = min(vmemmap_start, 1UL << MAX_PHYSMEM_BITS); Further, to make sure the identity mapping would not overlay with vmemmap, the size of identity mapping could be stripped like this: ident_map_size = min(ident_map_size, vmemmap_start); Similarily, any other memory that could be added (e.g DCSS segment) should not overlay with vmemmap as well and that is prevented by using vmemmap (VMEM_MAX_PHYS macro) as the upper limit. However, while the use of VMEM_MAX_PHYS brings the desired result it actually poses two issues: 1. As described, vmemmap is handled as a physical address, although it is actually a pointer to struct page in virtual address space. 2. As vmemmap is a virtual address it could have been located anywhere in the virtual address space. However, the desired necessity to honour MAX_PHYSMEM_BITS limit prevents that. Rework arch_get_mappable_range() callback in a way it does not use VMEM_MAX_PHYS macro and does not confuse the notion of virtual vs physical address spacees as result. That paves the way for moving vmemmap elsewhere and optimizing the virtual address space layout. Introduce max_mappable preserved boot variable and let function setup_kernel_memory_layout() set it up. As result, the rest of the code is does not need to know the virtual memory layout specifics. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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edc1e4b6 |
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26-Jul-2023 |
Sven Schnelle <svens@linux.ibm.com> |
s390/vmem: split pages when debug pagealloc is enabled Since commit bb1520d581a3 ("s390/mm: start kernel with DAT enabled") the kernel crashes early during boot when debug pagealloc is enabled: mem auto-init: stack:off, heap alloc:off, heap free:off addressing exception: 0005 ilc:2 [#1] SMP DEBUG_PAGEALLOC Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 6.5.0-rc3-09759-gc5666c912155 #630 [..] Krnl Code: 00000000001325f6: ec5600248064 cgrj %r5,%r6,8,000000000013263e 00000000001325fc: eb880002000c srlg %r8,%r8,2 #0000000000132602: b2210051 ipte %r5,%r1,%r0,0 >0000000000132606: b90400d1 lgr %r13,%r1 000000000013260a: 41605008 la %r6,8(%r5) 000000000013260e: a7db1000 aghi %r13,4096 0000000000132612: b221006d ipte %r6,%r13,%r0,0 0000000000132616: e3d0d0000171 lay %r13,4096(%r13) Call Trace: __kernel_map_pages+0x14e/0x320 __free_pages_ok+0x23a/0x5a8) free_low_memory_core_early+0x214/0x2c8 memblock_free_all+0x28/0x58 mem_init+0xb6/0x228 mm_core_init+0xb6/0x3b0 start_kernel+0x1d2/0x5a8 startup_continue+0x36/0x40 Kernel panic - not syncing: Fatal exception: panic_on_oops This is caused by using large mappings on machines with EDAT1/EDAT2. Add the code to split the mappings into 4k pages if debug pagealloc is enabled by CONFIG_DEBUG_PAGEALLOC_ENABLE_DEFAULT or the debug_pagealloc kernel command line option. Fixes: bb1520d581a3 ("s390/mm: start kernel with DAT enabled") Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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54372cf0 |
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03-Jul-2023 |
Alexander Gordeev <agordeev@linux.ibm.com> |
Revert "s390/mm: get rid of VMEM_MAX_PHYS macro" This reverts commit 456be42aa713e7f83b467db66ceae779431c7d9d. The assumption VMEM_MAX_PHYS should match ident_map_size is wrong. At least discontiguous saved segments (DCSS) could be loaded at addresses beyond ident_map_size and dcssblk device driver might fail as result. Reported-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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cada938a |
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28-Jun-2023 |
Heiko Carstens <hca@linux.ibm.com> |
s390: fix various typos Fix various typos found with codespell. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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688fcbbb |
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17-Jun-2023 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/vmem: fix virtual vs physical address confusion Fix virtual vs physical address confusion (which currently are the same). Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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456be42a |
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17-Jun-2023 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/mm: get rid of VMEM_MAX_PHYS macro VMEM_MAX_PHYS is supposed to be the highest physical address that can be added to the identity mapping. It should match ident_map_size, which has the same meaning. However, unlike ident_map_size it is not adjusted against various limiting factors (see the comment to setup_ident_map_size() function). That renders all checks against VMEM_MAX_PHYS invalid. Further, VMEM_MAX_PHYS is currently set to vmemmap, which is an address in virtual memory space. However, it gets compared against physical addresses in various locations. That works, because both address spaces are the same on s390, but otherwise it is wrong. Instead of fixing VMEM_MAX_PHYS misuse and semantics just remove it. Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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2ed8b509 |
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26-May-2023 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/kasan: fix insecure W+X mapping warning Since commit 3b5c3f000c2e ("s390/kasan: move shadow mapping to decompressor") the decompressor establishes mappings for the shadow memory and sets initial protection attributes to RWX. The decompressed kernel resets protection to RW+NX later on. In case a shadow memory range is not aligned on page boundary (e.g. as result of mem= kernel command line parameter use), the "Checked W+X mappings: FAILED, 1 W+X pages found" warning hits. Reported-by: Vasily Gorbik <gor@linux.ibm.com> Fixes: 557b19709da9 ("s390/kasan: move shadow mapping to decompressor") Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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f9b2d96c |
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02-Apr-2023 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm: use set_memory_*() helpers instead of open coding Given that set_memory_rox() and set_memory_rwnx() exist, it is possible to get rid of all open coded __set_memory() usages and replace them with proper helper calls everywhere. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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557b1970 |
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09-Feb-2023 |
Vasily Gorbik <gor@linux.ibm.com> |
s390/kasan: move shadow mapping to decompressor Since regular paging structs are initialized in decompressor already move KASAN shadow mapping to decompressor as well. This helps to avoid allocating KASAN required memory in 1 large chunk, de-duplicate paging structs creation code and start the uncompressed kernel with KASAN instrumentation right away. This also allows to avoid all pitfalls accidentally calling KASAN instrumented code during KASAN initialization. Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
fb9293b9 |
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28-Jan-2023 |
Vasily Gorbik <gor@linux.ibm.com> |
s390/vmem: remove unnecessary KASAN checks Kasan shadow memory area has been moved to the end of kernel address space since commit 9a39abb7c9aa ("s390/boot: simplify and fix kernel memory layout setup"), therefore skipping any memory ranges above VMALLOC_START in empty page tables cleanup code already handles KASAN shadow memory intersection case and explicit checks could be removed. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
108303b0 |
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28-Jan-2023 |
Vasily Gorbik <gor@linux.ibm.com> |
s390/vmem: fix empty page tables cleanup under KASAN Commit b9ff81003cf1 ("s390/vmem: cleanup empty page tables") introduced empty page tables cleanup in vmem code, but when the kernel is built with KASAN enabled the code has no effect due to wrong KASAN shadow memory intersection condition, which effectively ignores any memory range below KASAN shadow. Fix intersection condition to make code work as anticipated. Fixes: b9ff81003cf1 ("s390/vmem: cleanup empty page tables") Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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b4af0914 |
|
16-Jan-2023 |
Jiapeng Chong <jiapeng.chong@linux.alibaba.com> |
s390/vmem: use swap() instead of open coding it Swap is a function interface that provides exchange function. To avoid code duplication, we can use swap function. ./arch/s390/mm/vmem.c:680:10-11: WARNING opportunity for swap(). [hca@linux.ibm.com: get rid of all temp variables] Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=3786 Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Link: https://lore.kernel.org/r/20230117060223.58583-1-jiapeng.chong@linux.alibaba.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
bb1520d5 |
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13-Dec-2022 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/mm: start kernel with DAT enabled The setup of the kernel virtual address space is spread throughout the sources, boot stages and config options like this: 1. The available physical memory regions are queried and stored as mem_detect information for later use in the decompressor. 2. Based on the physical memory availability the virtual memory layout is established in the decompressor; 3. If CONFIG_KASAN is disabled the kernel paging setup code populates kernel pgtables and turns DAT mode on. It uses the information stored at step [1]. 4. If CONFIG_KASAN is enabled the kernel early boot kasan setup populates kernel pgtables and turns DAT mode on. It uses the information stored at step [1]. The kasan setup creates early_pg_dir directory and directly overwrites swapper_pg_dir entries to make shadow memory pages available. Move the kernel virtual memory setup to the decompressor and start the kernel with DAT turned on right from the very first istruction. That completely eliminates the boot phase when the kernel runs in DAT-off mode, simplies the overall design and consolidates pgtables setup. The identity mapping is created in the decompressor, while kasan shadow mappings are still created by the early boot kernel code. Share with decompressor the existing kasan memory allocator. It decreases the size of a newly requested memory block from pgalloc_pos and ensures that kernel image is not overwritten. pgalloc_low and pgalloc_pos pointers are made preserved boot variables for that. Use the bootdata infrastructure to setup swapper_pg_dir and invalid_pg_dir directories used by the kernel later. The interim early_pg_dir directory established by the kasan initialization code gets eliminated as result. As the kernel runs in DAT-on mode only the PSW_KERNEL_BITS define gets PSW_MASK_DAT bit by default. Additionally, the setup_lowcore_dat_off() and setup_lowcore_dat_on() routines get merged, since there is no DAT-off mode stage anymore. The memory mappings are created with RW+X protection that allows the early boot code setting up all necessary data and services for the kernel being booted. Just before the paging is enabled the memory protection is changed to RO+X for text, RO+NX for read-only data and RW+NX for kernel data and the identity mapping. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
2f0e8aae |
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24-Jul-2022 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/mm: rework memcpy_real() to avoid DAT-off mode Function memcpy_real() is an univeral data mover that does not require DAT mode to be able reading from a physical address. Its advantage is an ability to read from any address, even those for which no kernel virtual mapping exists. Although memcpy_real() is interrupt-safe, there are no handlers that make use of this function. The compiler instrumentation have to be disabled and separate no-DAT stack used to allow execution of the function once DAT mode is disabled. Rework memcpy_real() to overcome these shortcomings. As result, data copying (which is primarily reading out a crashed system memory by a user process) is executed on a regular stack with enabled interrupts. Also, use of memcpy_real_buf swap buffer becomes unnecessary and the swapping is eliminated. The above is achieved by using a fixed virtual address range that spans a single page and remaps that page repeatedly when memcpy_real() is called for a particular physical address. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
4df29d2b |
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20-Jul-2022 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/smp: rework absolute lowcore access Temporary unsetting of the prefix page in memcpy_absolute() routine poses a risk of executing code path with unexpectedly disabled prefix page. This rework avoids the prefix page uninstalling and disabling of normal and machine check interrupts when accessing the absolute zero memory. Although memcpy_absolute() routine can access the whole memory, it is only used to update the absolute zero lowcore. This rework therefore introduces a new mechanism for the absolute zero lowcore access and scraps memcpy_absolute() routine for good. Instead, an area is reserved in the virtual memory that is used for the absolute lowcore access only. That area holds an array of 8KB virtual mappings - one per CPU. Whenever a CPU is brought online, the corresponding item is mapped to the real address of the previously installed prefix page. The absolute zero lowcore access works like this: a CPU calls the new primitive get_abs_lowcore() to obtain its 8KB mapping as a pointer to the struct lowcore. Virtual address references to that pointer get translated to the real addresses of the prefix page, which in turn gets swapped with the absolute zero memory addresses due to prefixing. Once the pointer is not needed it must be released with put_abs_lowcore() primitive: struct lowcore *abs_lc; unsigned long flags; abs_lc = get_abs_lowcore(&flags); abs_lc->... = ...; put_abs_lowcore(abs_lc, flags); To ensure the described mechanism works large segment- and region- table entries must be avoided for the 8KB mappings. Failure to do so results in usage of Region-Frame Absolute Address (RFAA) or Segment-Frame Absolute Address (SFAA) large page fields. In that case absolute addresses would be used to address the prefix page instead of the real ones and the prefixing would get bypassed. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
b193d2d4 |
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05-Sep-2022 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm: split lowcore pages with set_memory_4k() Use set_memory_4k() to split lowcore pages within the kernel mapping instead of using the quite subtle !addr check within modify_pmd_table() and modify_pud_table() to prevent large pages for address zero. With this lowcore might be mapped with 1MB / 2GB frames and only later will be split. This way this mapping is handled like every other. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
5e441f61 |
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06-Aug-2022 |
Alexander Gordeev <agordeev@linux.ibm.com> |
Revert "s390/smp: rework absolute lowcore access" This reverts commit 7d06fed77b7d8fc9f6cc41b4e3f2823d32532ad8. This introduced vmem_mutex locking from vmem_map_4k_page() function called from smp_reinit_ipl_cpu() with interrupts disabled. While it is a pre-SMP early initcall no other CPUs running in parallel nor other code taking vmem_mutex on this boot stage - it still needs to be fixed. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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#
7d06fed7 |
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20-Jul-2022 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/smp: rework absolute lowcore access Temporary unsetting of the prefix page in memcpy_absolute() routine poses a risk of executing code path with unexpectedly disabled prefix page. This rework avoids the prefix page uninstalling and disabling of normal and machine check interrupts when accessing the absolute zero memory. Although memcpy_absolute() routine can access the whole memory, it is only used to update the absolute zero lowcore. This rework therefore introduces a new mechanism for the absolute zero lowcore access and scraps memcpy_absolute() routine for good. Instead, an area is reserved in the virtual memory that is used for the absolute lowcore access only. That area holds an array of 8KB virtual mappings - one per CPU. Whenever a CPU is brought online, the corresponding item is mapped to the real address of the previously installed prefix page. The absolute zero lowcore access works like this: a CPU calls the new primitive get_abs_lowcore() to obtain its 8KB mapping as a pointer to the struct lowcore. Virtual address references to that pointer get translated to the real addresses of the prefix page, which in turn gets swapped with the absolute zero memory addresses due to prefixing. Once the pointer is not needed it must be released with put_abs_lowcore() primitive: struct lowcore *abs_lc; unsigned long flags; abs_lc = get_abs_lowcore(&flags); abs_lc->... = ...; put_abs_lowcore(abs_lc, flags); To ensure the described mechanism works large segment- and region- table entries must be avoided for the 8KB mappings. Failure to do so results in usage of Region-Frame Absolute Address (RFAA) or Segment-Frame Absolute Address (SFAA) large page fields. In that case absolute addresses would be used to address the prefix page instead of the real ones and the prefixing would get bypassed. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
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#
4efd417f |
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24-Feb-2022 |
Vasily Gorbik <gor@linux.ibm.com> |
s390: raise minimum supported machine generation to z10 Machine generations up to z9 (released in May 2006) have been officially out of service for several years now (z9 end of service - January 31, 2019). No distributions build kernels supporting those old machine generations anymore, except Debian, which seems to pick the oldest supported generation. The team supporting Debian on s390 has been notified about the change. Raising minimum supported machine generation to z10 helps to reduce maintenance cost and effectively remove code, which is not getting enough testing coverage due to lack of older hardware and distributions support. Besides that this unblocks some optimization opportunities and allows to use wider instruction set in asm files for future features implementation. Due to this change spectre mitigation and usercopy implementations could be drastically simplified and many newer instructions could be converted from ".insn" encoding to instruction names. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
b8e3b379 |
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21-Feb-2022 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm: use set_pXd()/set_pte() helper functions everywhere Use the new set_pXd()/set_pte() helper functions at all places where page table entries are modified. Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
f36e7c98 |
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27-Jan-2022 |
Heiko Carstens <hca@linux.ibm.com> |
s390: remove invalid email address of Heiko Carstens Remove my old invalid email address which can be found in a couple of files. Instead of updating it, just remove my contact data completely from source files. We have git and other tools which allow to figure out who is responsible for what with recent contact data. Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
3b051e89 |
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07-Apr-2021 |
Sven Schnelle <svens@linux.ibm.com> |
s390: add support for BEAR enhancement facility The Breaking-Event-Address-Register (BEAR) stores the address of the last breaking event instruction. Breaking events are usually instructions that change the program flow - for example branches, and instructions that modify the address in the PSW like lpswe. This is useful for debugging wild branches, because one could easily figure out where the wild branch was originating from. What is problematic is that lpswe is considered a breaking event, and therefore overwrites BEAR on kernel exit. The BEAR enhancement facility adds new instructions that allow to save/restore BEAR and also an lpswey instruction that doesn't cause a breaking event. So we can save BEAR on kernel entry and restore it on exit to user space. Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
c78d0c74 |
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04-Aug-2021 |
Heiko Carstens <hca@linux.ibm.com> |
s390: rename dma section to amode31 The dma section name is confusing, since the code which resides within that section has nothing to do with direct memory access. Instead the limitation is that the code has to run in 31 bit addressing mode, and therefore has to reside below 2GB. So the name was chosen since ZONE_DMA is the same region. To reduce confusion rename the section to amode31, which hopefully describes better what this is about. Note: this will also change vmcoreinfo strings - SDMA=... gets renamed to SAMODE31=... - EDMA=... gets renamed to EAMODE31=... Acked-by: Vasily Gorbik <gor@linux.ibm.com> Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
7707248a |
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25-Feb-2021 |
Anshuman Khandual <anshuman.khandual@arm.com> |
s390/mm: define arch_get_mappable_range() This overrides arch_get_mappabble_range() on s390 platform which will be used with recently added generic framework. It modifies the existing range check in vmem_add_mapping() using arch_get_mappable_range(). It also adds a VM_BUG_ON() check that would ensure that mhp_range_allowed() has already been called on the hotplug path. Link: https://lkml.kernel.org/r/1612149902-7867-4-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pankaj.gupta@cloud.ionos.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: teawater <teawaterz@linux.alibaba.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
4c86d2f5 |
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11-Feb-2021 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/mm: fix phys vs virt confusion in vmem_*() functions family Due to historical reasons vmem_*() functions misuse or ignore the notion of physical vs virtual addresses difference. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
12bb4c68 |
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10-Nov-2020 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/vmem: make variable and function names consistent Rename some variable and functions to better clarify what they are and what they do. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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af71657c |
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10-Nov-2020 |
Alexander Gordeev <agordeev@linux.ibm.com> |
s390/vmem: remove redundant check Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
b10d6bca |
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13-Oct-2020 |
Mike Rapoport <rppt@kernel.org> |
arch, drivers: replace for_each_membock() with for_each_mem_range() There are several occurrences of the following pattern: for_each_memblock(memory, reg) { start = __pfn_to_phys(memblock_region_memory_base_pfn(reg); end = __pfn_to_phys(memblock_region_memory_end_pfn(reg)); /* do something with start and end */ } Using for_each_mem_range() iterator is more appropriate in such cases and allows simpler and cleaner code. [akpm@linux-foundation.org: fix arch/arm/mm/pmsa-v7.c build] [rppt@linux.ibm.com: mips: fix cavium-octeon build caused by memblock refactoring] Link: http://lkml.kernel.org/r/20200827124549.GD167163@linux.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Daniel Axtens <dja@axtens.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Emil Renner Berthing <kernel@esmil.dk> Cc: Hari Bathini <hbathini@linux.ibm.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: https://lkml.kernel.org/r/20200818151634.14343-13-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
bffc2f7a |
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21-Aug-2020 |
Vasily Gorbik <gor@linux.ibm.com> |
s390/vmem: fix vmem_add_range for 4-level paging The kernel currently crashes if 4-level paging is used. Add missing p4d_populate for just allocated pud entry. Fixes: 3e0d3e408e63 ("s390/vmem: consolidate vmem_add_range() and vmem_remove_range()") Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
9a996c67 |
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23-Jul-2020 |
Heiko Carstens <hca@linux.ibm.com> |
s390/vmemmap: coding style updates Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
2c114df0 |
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22-Jul-2020 |
David Hildenbrand <david@redhat.com> |
s390/vmemmap: avoid memset(PAGE_UNUSED) when adding consecutive sections Let's avoid memset(PAGE_UNUSED) when adding consecutive sections, whereby the vmemmap of a single section does not span full PMDs. Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20200722094558.9828-10-david@redhat.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
cd5781d6 |
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22-Jul-2020 |
David Hildenbrand <david@redhat.com> |
s390/vmemmap: remember unused sub-pmd ranges With a memmap size of 56 bytes or 72 bytes per page, the memmap for a 256 MB section won't span full PMDs. As we populate single sections and depopulate single sections, the depopulation step would not be able to free all vmemmap pmds anymore. Do it similarly to x86, marking the unused memmap ranges in a special way (pad it with 0xFD). This allows us to add/remove sections, cleaning up all allocated vmemmap pages even if the memmap size is not multiple of 16 bytes per page. A 56 byte memmap can, for example, be created with !CONFIG_MEMCG and !CONFIG_SLUB. Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20200722094558.9828-9-david@redhat.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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f2057b42 |
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22-Jul-2020 |
David Hildenbrand <david@redhat.com> |
s390/vmemmap: fallback to PTEs if mapping large PMD fails Let's fallback to single pages if short on huge pages. No need to stop memory hotplug. Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20200722094558.9828-8-david@redhat.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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b9ff8100 |
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22-Jul-2020 |
David Hildenbrand <david@redhat.com> |
s390/vmem: cleanup empty page tables Let's cleanup empty page tables. Consider only page tables that fully fall into the idendity mapping and the vmemmap range. As there are no valid accesses to vmem/vmemmap within non-populated ranges, the single tlb flush at the end should be sufficient. Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20200722094558.9828-7-david@redhat.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
aa18e0e6 |
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22-Jul-2020 |
David Hildenbrand <david@redhat.com> |
s390/vmemmap: take the vmem_mutex when populating/freeing Let's synchronize all accesses to the 1:1 and vmemmap mappings. This will be especially relevant when wanting to cleanup empty page tables that could be shared by both. Avoid races when removing tables that might be just about to get reused. Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20200722094558.9828-6-david@redhat.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
c00f05a9 |
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22-Jul-2020 |
David Hildenbrand <david@redhat.com> |
s390/vmemmap: cleanup when vmemmap_populate() fails Cleanup what we partially added in case vmemmap_populate() fails. For vmem, this is already handled by vmem_add_mapping(). Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20200722094558.9828-5-david@redhat.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
9ec8fa8d |
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22-Jul-2020 |
David Hildenbrand <david@redhat.com> |
s390/vmemmap: extend modify_pagetable() to handle vmemmap Extend our shiny new modify_pagetable() to handle !direct (vmemmap) mappings. Convert vmemmap_populate() and implement vmemmap_free(). Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20200722094558.9828-4-david@redhat.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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#
3e0d3e40 |
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22-Jul-2020 |
David Hildenbrand <david@redhat.com> |
s390/vmem: consolidate vmem_add_range() and vmem_remove_range() We want to have only a single pagetable walker and reuse the same functionality for vmemmap handling. Let's start by consolidating vmem_add_range() and vmem_remove_range(), converting it into a recursive implementation. A recursive implementation makes it easier to expand individual cases without harming readability. In addition, we minimize traversing the whole hierarchy over and over again. One change is that we don't unmap large PMDs/PUDs when not completely covered by the request, something that should never happen with direct mappings, unless one would be removing in other granularity than added, which would be broken already. Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20200722094558.9828-3-david@redhat.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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8398b226 |
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22-Jul-2020 |
David Hildenbrand <david@redhat.com> |
s390/vmem: rename vmem_add_mem() to vmem_add_range() Let's match the name to vmem_remove_range(). Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20200722094558.9828-2-david@redhat.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
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f05f62d0 |
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25-Jun-2020 |
David Hildenbrand <david@redhat.com> |
s390/vmem: get rid of memory segment list I can't come up with a satisfying reason why we still need the memory segment list. We used to represent in the list: - boot memory - standby memory added via add_memory() - loaded dcss segments When loading/unloading dcss segments, we already track them in a separate list and check for overlaps (arch/s390/mm/extmem.c:segment_overlaps_others()) when loading segments. The overlap check was introduced for some segments in commit b2300b9efe1b ("[S390] dcssblk: add >2G DCSSs support and stacked contiguous DCSSs support.") and was extended to cover all dcss segments in commit ca57114609d1 ("s390/extmem: remove code for 31 bit addressing mode"). Although I doubt that overlaps with boot memory and standby memory are relevant, let's reshuffle the checks in load_segment() to request the resource first. This will bail out in case we have overlaps with other resources (esp. boot memory and standby memory). The order is now different compared to segment_unload() and segment_unload(), but that should not matter. This smells like a leftover from ancient times, let's get rid of it. We can now convert vmem_remove_mapping() into a void function - everybody ignored the return value already. Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20200625150029.45019-1-david@redhat.com> Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Tested-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [DCSS] Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
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#
e31cf2f4 |
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08-Jun-2020 |
Mike Rapoport <rppt@kernel.org> |
mm: don't include asm/pgtable.h if linux/mm.h is already included Patch series "mm: consolidate definitions of page table accessors", v2. The low level page table accessors (pXY_index(), pXY_offset()) are duplicated across all architectures and sometimes more than once. For instance, we have 31 definition of pgd_offset() for 25 supported architectures. Most of these definitions are actually identical and typically it boils down to, e.g. static inline unsigned long pmd_index(unsigned long address) { return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address); } These definitions can be shared among 90% of the arches provided XYZ_SHIFT, PTRS_PER_XYZ and xyz_page_vaddr() are defined. For architectures that really need a custom version there is always possibility to override the generic version with the usual ifdefs magic. These patches introduce include/linux/pgtable.h that replaces include/asm-generic/pgtable.h and add the definitions of the page table accessors to the new header. This patch (of 12): The linux/mm.h header includes <asm/pgtable.h> to allow inlining of the functions involving page table manipulations, e.g. pte_alloc() and pmd_alloc(). So, there is no point to explicitly include <asm/pgtable.h> in the files that include <linux/mm.h>. The include statements in such cases are remove with a simple loop: for f in $(git grep -l "include <linux/mm.h>") ; do sed -i -e '/include <asm\/pgtable.h>/ d' $f done Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-1-rppt@kernel.org Link: http://lkml.kernel.org/r/20200514170327.31389-2-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
0b38b5e1 |
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22-Jan-2020 |
Sven Schnelle <svens@linux.ibm.com> |
s390: prevent leaking kernel address in BEAR When userspace executes a syscall or gets interrupted, BEAR contains a kernel address when returning to userspace. This make it pretty easy to figure out where the kernel is mapped even with KASLR enabled. To fix this, add lpswe to lowcore and always execute it there, so userspace sees only the lowcore address of lpswe. For this we have to extend both critical_cleanup and the SWITCH_ASYNC macro to also check for lpswe addresses in lowcore. Fixes: b2d24b97b2a9 ("s390/kernel: add support for kernel address space layout randomization (KASLR)") Cc: <stable@vger.kernel.org> # v5.2+ Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
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#
a80313ff |
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03-Feb-2019 |
Gerald Schaefer <gerald.schaefer@linux.ibm.com> |
s390/kernel: introduce .dma sections With a relocatable kernel that could reside at any place in memory, code and data that has to stay below 2 GB needs special handling. This patch introduces .dma sections for such text, data and ex_table. The sections will be part of the decompressor kernel, so they will not be relocated and stay below 2 GB. Their location is passed over to the decompressed / relocated kernel via the .boot.preserved.data section. The duald and aste for control register setup also need to stay below 2 GB, so move the setup code from arch/s390/kernel/head64.S to arch/s390/boot/head.S. The duct and linkage_stack could reside above 2 GB, but their content has to be preserved for the decompresed kernel, so they are also moved into the .dma section. The start and end address of the .dma sections is added to vmcoreinfo, for crash support, to help debugging in case the kernel crashed there. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
57c8a661 |
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30-Oct-2018 |
Mike Rapoport <rppt@linux.vnet.ibm.com> |
mm: remove include/linux/bootmem.h Move remaining definitions and declarations from include/linux/bootmem.h into include/linux/memblock.h and remove the redundant header. The includes were replaced with the semantic patch below and then semi-automated removal of duplicated '#include <linux/memblock.h> @@ @@ - #include <linux/bootmem.h> + #include <linux/memblock.h> [sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au [sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au [sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal] Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Serge Semin <fancer.lancer@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
9a8dd708 |
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30-Oct-2018 |
Mike Rapoport <rppt@linux.vnet.ibm.com> |
memblock: rename memblock_alloc{_nid,_try_nid} to memblock_phys_alloc* Make it explicit that the caller gets a physical address rather than a virtual one. This will also allow using meblock_alloc prefix for memblock allocations returning virtual address, which is done in the following patches. The conversion is done using the following semantic patch: @@ expression e1, e2, e3; @@ ( - memblock_alloc(e1, e2) + memblock_phys_alloc(e1, e2) | - memblock_alloc_nid(e1, e2, e3) + memblock_phys_alloc_nid(e1, e2, e3) | - memblock_alloc_try_nid(e1, e2, e3) + memblock_phys_alloc_try_nid(e1, e2, e3) ) Link: http://lkml.kernel.org/r/1536927045-23536-7-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Serge Semin <fancer.lancer@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
24b6d416 |
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29-Dec-2017 |
Christoph Hellwig <hch@lst.de> |
mm: pass the vmem_altmap to vmemmap_free We can just pass this on instead of having to do a radix tree lookup without proper locking a few levels into the callchain. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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#
7b73d978 |
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29-Dec-2017 |
Christoph Hellwig <hch@lst.de> |
mm: pass the vmem_altmap to vmemmap_populate We can just pass this on instead of having to do a radix tree lookup without proper locking a few levels into the callchain. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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#
ead7a22e |
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08-Nov-2017 |
Heiko Carstens <hca@linux.ibm.com> |
s390: avoid undefined behaviour At a couple of places smatch emits warnings like this: arch/s390/mm/vmem.c:409 vmem_map_init() warn: right shifting more than type allows In fact shifting a signed type right is undefined. Avoid this and add an unsigned long cast. The shifted values are always positive. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
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#
978fa72e |
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01-Nov-2017 |
Heiko Carstens <hca@linux.ibm.com> |
s390: remove named saved segment support Remove the support to create a z/VM named saved segment (NSS). This feature is not supported since quite a while in favour of jump labels, function tracing and (now) CPU alternatives. All of these features require to write to the kernel text section which is not possible if the kernel is contained within an NSS. Given that memory savings are minimal if kernel images are shared and in addition updates of shared images are painful, the NSS feature can be removed. Reviewed-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
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#
b2441318 |
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01-Nov-2017 |
Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
41879ff6 |
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04-Oct-2017 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm: use memset64 instead of clear_table Use memset64 instead of the (now) open-coded variant clear_table. Performance wise there is no difference. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
a01ef308 |
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16-Jun-2017 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm,vmem: simplify region and segment table allocation code Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
1aea9b3f |
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24-Apr-2017 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
s390/mm: implement 5 level pages tables Add the logic to upgrade the page table for a 64-bit process to five levels. This increases the TASK_SIZE from 8PB to 16EB-4K. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
e6c7c630 |
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08-May-2017 |
Laura Abbott <labbott@redhat.com> |
s390: use set_memory.h header set_memory_* functions have moved to set_memory.h. Switch to this explicitly Link: http://lkml.kernel.org/r/1488920133-27229-5-git-send-email-labbott@redhat.com Signed-off-by: Laura Abbott <labbott@redhat.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
ff24b07a |
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09-Feb-2017 |
Paul Gortmaker <paul.gortmaker@windriver.com> |
s390: mm: Audit and remove any unnecessary uses of module.h Historically a lot of these existed because we did not have a distinction between what was modular code and what was providing support to modules via EXPORT_SYMBOL and friends. That changed when we forked out support for the latter into the export.h file. This means we should be able to reduce the usage of module.h in code that is obj-y Makefile or bool Kconfig. The advantage in doing so is that module.h itself sources about 15 other headers; adding significantly to what we feed cpp, and it can obscure what headers we are effectively using. Since module.h was the source for init.h (for __init) and for export.h (for EXPORT_SYMBOL) we consider each change instance for the presence of either and replace as needed. An instance where module_param was used without moduleparam.h was also fixed, as well as an implict use of asm/elf.h header. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
57d7f939 |
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22-Mar-2016 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
s390: add no-execute support Bit 0x100 of a page table, segment table of region table entry can be used to disallow code execution for the virtual addresses associated with the entry. There is one tricky bit, the system call to return from a signal is part of the signal frame written to the user stack. With a non-executable stack this would stop working. To avoid breaking things the protection fault handler checks the opcode that caused the fault for 0x0a77 (sys_sigreturn) and 0x0aad (sys_rt_sigreturn) and injects a system call. This is preferable to the alternative solution with a stub function in the vdso because it works for vdso=off and statically linked binaries as well. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
9e427365 |
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18-Oct-2016 |
Heiko Carstens <hca@linux.ibm.com> |
s390: convert remaining bootmem allocations to memblock Get rid of all remaining alloc_bootmem calls and use memblock_alloc instead everywhere. This way we get rid of the inconsistent mixture of alloc_bootmem and memblock_alloc usages. Two of the alloc_bootmem_low calls within arch/s390/kernel/setup.c are replaced with memblock_alloc calls that don't enforce that the allocated memory is below 2GB. This restriction was never necessary. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
d07a980c |
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07-Jun-2016 |
Heiko Carstens <hca@linux.ibm.com> |
s390: add proper __ro_after_init support On s390 __ro_after_init is currently mapped to __read_mostly which means that data marked as __ro_after_init will not be protected. Reason for this is that the common code __ro_after_init implementation is x86 centric: the ro_after_init data section was added to rodata, since x86 enables write protection to kernel text and rodata very late. On s390 we have write protection for these sections enabled with the initial page tables. So adding the ro_after_init data section to rodata does not work on s390. In order to make __ro_after_init work properly on s390 move the ro_after_init data, right behind rodata. Unlike the rodata section it will be marked read-only later after all init calls happened. This s390 specific implementation adds new __start_ro_after_init and __end_ro_after_init labels. Everything in between will be marked read-only after the init calls happened. In addition to the __ro_after_init data move also the exception table there, since from a practical point of view it fits the __ro_after_init requirements. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
37cd944c |
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20-May-2016 |
Heiko Carstens <hca@linux.ibm.com> |
s390/pgtable: add mapping statistics Add statistics that show how memory is mapped within the kernel identity mapping. This is more or less the same like git commit ce0c0e50f94e ("x86, generic: CPA add statistics about state of direct mapping v4") for x86. I also intentionally copied the lower case "k" within DirectMap4k vs the upper case "M" and "G" within the two other lines. Let's have consistent inconsistencies across architectures. The output of /proc/meminfo now contains these additional lines: DirectMap4k: 2048 kB DirectMap1M: 3991552 kB DirectMap2G: 4194304 kB The implementation on s390 is lockless unlike the x86 version, since I assume changes to the kernel mapping are a very rare event. Therefore it really doesn't matter if these statistics could potentially be inconsistent if read while kernel pages tables are being changed. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
bab247ff |
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10-May-2016 |
Heiko Carstens <hca@linux.ibm.com> |
s390/vmem: simplify vmem code for read-only mappings For the kernel identity mapping map everything read-writeable and subsequently call set_memory_ro() to make the ro section read-only. This simplifies the code a lot. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
e8a97e42 |
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17-May-2016 |
Heiko Carstens <hca@linux.ibm.com> |
s390/pageattr: allow kernel page table splitting set_memory_ro() and set_memory_rw() currently only work on 4k mappings, which is good enough for module code aka the vmalloc area. However we stumbled already twice into the need to make this also work on larger mappings: - the ro after init patch set - the crash kernel resize code Therefore this patch implements automatic kernel page table splitting if e.g. set_memory_ro() would be called on parts of a 2G mapping. This works quite the same as the x86 code, but is much simpler. In order to make this work and to be architecturally compliant we now always use the csp, cspg or crdte instructions to replace valid page table entries. This means that set_memory_ro() and set_memory_rw() will be much more expensive than before. In order to avoid huge latencies the code contains a couple of cond_resched() calls. The current code only splits page tables, but does not merge them if it would be possible. The reason for this is that currently there is no real life scenarion where this would really happen. All current use cases that I know of only change access rights once during the life time. If that should change we can still implement kernel page table merging at a later time. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
5aa29975 |
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16-May-2016 |
Heiko Carstens <hca@linux.ibm.com> |
s390/vmem: make use of pte_clear() Use pte_clear() instead of open-coding it. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
2dffdcba |
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11-May-2016 |
Heiko Carstens <hca@linux.ibm.com> |
s390/vmem: introduce and use SEGMENT_KERNEL and REGION3_KERNEL Instead of open-coded SEGMENT_KERNEL and REGION3_KERNEL assignments use defines. Also to make e.g. pmd_wrprotect() work on the kernel mapping a couple more flags must be set. Therefore add the missing flags also. In order to make everything symmetrical this patch also adds software dirty, young, read and write bits for region 3 table entries. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
2e9996fc |
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13-May-2016 |
Heiko Carstens <hca@linux.ibm.com> |
s390/vmem: align segment and region tables to 16k Usually segment and region tables are 16k aligned due to the way the buddy allocator works. This is not true for the vmem code which only asks for a 4k alignment. In order to be consistent enforce a 16k alignment here as well. This alignment will be assumed and therefore is required by the pageattr code. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
c53db522 |
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09-May-2016 |
Heiko Carstens <hca@linux.ibm.com> |
s390/vmem: remove unused function parameter vmem_pte_alloc() has an unused function parameter. Let's remove it. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
c34a6905 |
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09-May-2016 |
Heiko Carstens <hca@linux.ibm.com> |
s390/vmem: fix identity mapping The identity mapping is suboptimal for the last 2GB frame. The mapping will be established with a mix of 4KB and 1MB mappings instead of a single 2GB mapping. This happens because of a off-by-one bug introduced with commit 50be63450728 ("s390/mm: Convert bootmem to memblock"). Currently the identity mapping looks like this: 0x0000000080000000-0x0000000180000000 4G PUD RW 0x0000000180000000-0x00000001fff00000 2047M PMD RW 0x00000001fff00000-0x0000000200000000 1M PTE RW With the bug fixed it looks like this: 0x0000000080000000-0x0000000200000000 6G PUD RW Fixes: 50be63450728 ("s390/mm: Convert bootmem to memblock") Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
10917b83 |
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15-Mar-2016 |
Christian Borntraeger <borntraeger@de.ibm.com> |
s390: query dynamic DEBUG_PAGEALLOC setting We can use debug_pagealloc_enabled() to check if we can map the identity mapping with 1MB/2GB pages as well as to print the current setting in dump_stack. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: David Rientjes <rientjes@google.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
5a79859a |
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12-Feb-2015 |
Heiko Carstens <hca@linux.ibm.com> |
s390: remove 31 bit support Remove the 31 bit support in order to reduce maintenance cost and effectively remove dead code. Since a couple of years there is no distribution left that comes with a 31 bit kernel. The 31 bit kernel also has been broken since more than a year before anybody noticed. In addition I added a removal warning to the kernel shown at ipl for 5 minutes: a960062e5826 ("s390: add 31 bit warning message") which let everybody know about the plan to remove 31 bit code. We didn't get any response. Given that the last 31 bit only machine was introduced in 1999 let's remove the code. Anybody with 31 bit user space code can still use the compat mode. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
6a5c1482 |
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22-Sep-2014 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm: remove change bit override support Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
70c9d296 |
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20-Sep-2014 |
Heiko Carstens <hca@linux.ibm.com> |
s390/vmemmap: remove memset call from vmemmap_populate() If the vmemmap array gets filled with large pages we allocate those pages with vmemmap_alloc_block(), which returns cleared pages. Only for single 4k pages we call our own vmem_alloc_pages() which does not return cleared pages. However we can also call vmemmap_alloc_block() to allocate the 4k pages. This way we can also make sure the vmemmap array is cleared after its population. Therefore we can remove the memset at the end of the function which would clear the vmmemmap array a second time on machines which do support EDAT1. On very large configurations this can save us several seconds. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
527e30b4 |
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30-Apr-2014 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
KVM: s390/mm: use radix trees for guest to host mappings Store the target address for the gmap segments in a radix tree instead of using invalid segment table entries. gmap_translate becomes a simple radix_tree_lookup, gmap_fault is split into the address translation with gmap_translate and the part that does the linking of the gmap shadow page table with the process page table. A second radix tree is used to keep the pointers to the segment table entries for segments that are mapped in the guest address space. On unmap of a segment the pointer is retrieved from the radix tree and is used to carry out the segment invalidation in the gmap shadow page table. As the radix tree can only store one pointer, each host segment may only be mapped to exactly one guest location. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
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50be6345 |
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29-Jan-2014 |
Philipp Hachtmann <phacht@linux.vnet.ibm.com> |
s390/mm: Convert bootmem to memblock The original bootmem allocator is getting replaced by memblock. To cover the needs of the s390 kdump implementation the physical memory list is used. With this patch the bootmem allocator and its bitmaps are completely removed from s390. Signed-off-by: Philipp Hachtmann <phacht@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
1b948d6c |
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03-Apr-2014 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
s390/mm,tlb: optimize TLB flushing for zEC12 The zEC12 machines introduced the local-clearing control for the IDTE and IPTE instruction. If the control is set only the TLB of the local CPU is cleared of entries, either all entries of a single address space for IDTE, or the entry for a single page-table entry for IPTE. Without the local-clearing control the TLB flush is broadcasted to all CPUs in the configuration, which is expensive. The reset of the bit mask of the CPUs that need flushing after a non-local IDTE is tricky. As TLB entries for an address space remain in the TLB even if the address space is detached a new bit field is required to keep track of attached CPUs vs. CPUs in the need of a flush. After a non-local flush with IDTE the bit-field of attached CPUs is copied to the bit-field of CPUs in need of a flush. The ordering of operations on cpu_attach_mask, attach_count and mm_cpumask(mm) is such that an underindication in mm_cpumask(mm) is prevented but an overindication in mm_cpumask(mm) is possible. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
0944fe3f |
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23-Jul-2013 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
s390/mm: implement software referenced bits The last remaining use for the storage key of the s390 architecture is reference counting. The alternative is to make page table entries invalid while they are old. On access the fault handler marks the pte/pmd as young which makes the pte/pmd valid if the access rights allow read access. The pte/pmd invalidations required for software managed reference bits cost a bit of performance, on the other hand the RRBE/RRBM instructions to read and reset the referenced bits are quite expensive as well. Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
e5098611 |
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23-Jul-2013 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
s390/mm: cleanup page table definitions Improve the encoding of the different pte types and the naming of the page, segment table and region table bits. Due to the different pte encoding the hugetlbfs primitives need to be adapted as well. To improve compatability with common code make the huge ptes use the encoding of normal ptes. The conversion between the pte and pmd encoding for a huge pte is done with set_huge_pte_at and huge_ptep_get. Overall the code is now easier to understand. Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
996b4a7d |
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30-Apr-2013 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mem_detect: remove artificial kdump memory types Simplify the memory detection code a bit by removing the CHUNK_OLDMEM and CHUNK_CRASHK memory types. They are not needed. Everything that is needed is a mechanism to insert holes into the detected memory. Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
0aad818b |
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29-Apr-2013 |
Johannes Weiner <hannes@cmpxchg.org> |
sparse-vmemmap: specify vmemmap population range in bytes The sparse code, when asking the architecture to populate the vmemmap, specifies the section range as a starting page and a number of pages. This is an awkward interface, because none of the arch-specific code actually thinks of the range in terms of 'struct page' units and always translates it to bytes first. In addition, later patches mix huge page and regular page backing for the vmemmap. For this, they need to call vmemmap_populate_basepages() on sub-section ranges with PAGE_SIZE and PMD_SIZE in mind. But these are not necessarily multiples of the 'struct page' size and so this unit is too coarse. Just translate the section range into bytes once in the generic sparse code, then pass byte ranges down the stack. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Ben Hutchings <ben@decadent.org.uk> Cc: Bernhard Schmidt <Bernhard.Schmidt@lrz.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: David S. Miller <davem@davemloft.net> Tested-by: David S. Miller <davem@davemloft.net> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
17ea345a |
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15-Feb-2013 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm: ignore change bit for vmemmap Add hint to the page tables that we don't care about the change bit in storage keys that belong to vmemmap pages. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
0197518c |
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22-Feb-2013 |
Tang Chen <tangchen@cn.fujitsu.com> |
memory-hotplug: remove memmap of sparse-vmemmap Introduce a new API vmemmap_free() to free and remove vmemmap pagetables. Since pagetable implements are different, each architecture has to provide its own version of vmemmap_free(), just like vmemmap_populate(). Note: vmemmap_free() is not implemented for ia64, ppc, s390, and sparc. [mhocko@suse.cz: fix implicit declaration of remove_pagetable] Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Jianguo Wu <wujianguo@huawei.com> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com> Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Jiang Liu <jiang.liu@huawei.com> Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Wu Jianguo <wujianguo@huawei.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
abf09bed |
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07-Nov-2012 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
s390/mm: implement software dirty bits The s390 architecture is unique in respect to dirty page detection, it uses the change bit in the per-page storage key to track page modifications. All other architectures track dirty bits by means of page table entries. This property of s390 has caused numerous problems in the past, e.g. see git commit ef5d437f71afdf4a "mm: fix XFS oops due to dirty pages without buffers on s390". To avoid future issues in regard to per-page dirty bits convert s390 to a fault based software dirty bit detection mechanism. All user page table entries which are marked as clean will be hardware read-only, even if the pte is supposed to be writable. A write by the user process will trigger a protection fault which will cause the user pte to be marked as dirty and the hardware read-only bit is removed. With this change the dirty bit in the storage key is irrelevant for Linux as a host, but the storage key is still required for KVM guests. The effect is that page_test_and_clear_dirty and the related code can be removed. The referenced bit in the storage key is still used by the page_test_and_clear_young primitive to provide page age information. For page cache pages of mappings with mapping_cap_account_dirty there will not be any change in behavior as the dirty bit tracking already uses read-only ptes to control the amount of dirty pages. Only for swap cache pages and pages of mappings without mapping_cap_account_dirty there can be additional protection faults. To avoid an excessive number of additional faults the mk_pte primitive checks for PageDirty if the pgprot value allows for writes and pre-dirties the pte. That avoids all additional faults for tmpfs and shmem pages until these pages are added to the swap cache. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
f7817968 |
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16-Oct-2012 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm,vmemmap: use 1MB frames for vmemmap Use 1MB frames for vmemmap if EDAT1 is available in order to reduce TLB pressure Always use a 1MB frame even if its only partially needed for struct pages. Otherwise we would end up with a mix of large frame and page mappings, because vmemmap_populate gets called for each section (256MB -> 3.5MB memmap) separately. Worst case is that we would waste 512KB. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
18da2369 |
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08-Oct-2012 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm,vmem: use 2GB frames for identity mapping Use 2GB frames for indentity mapping if EDAT2 is available to reduce TLB pressure. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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fc7e48aa |
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07-Oct-2012 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm,vmem: fix vmem_add_mem()/vmem_remove_range() vmem_add_mem() should only then insert a large page if pmd_none() is true for the specific entry. We might have a leftover from a previous mapping. In addition make vmem_remove_range()'s page table walk code more complete and fix a couple of potential endless loops (which can never happen :). Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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8fe234d3 |
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04-Oct-2012 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm: fix mapping of read-only kernel text section Within the identity mapping the kernel text section is mapped read-only. However when mapping the first and last page of the text section we must round upwards and downwards respectively, if only parts of a page belong to the section. Otherwise potential rw data can be mapped read-only. So the rounding must be done just the other way we have it right now. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
378b1e7a |
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30-Sep-2012 |
Heiko Carstens <hca@linux.ibm.com> |
s390/mm: fix pmd_huge() usage for kernel mapping pmd_huge() will always return 0 on !HUGETLBFS, however we use that helper function when walking the kernel page tables to decide if we have a 1MB page frame or not. Since we create 1MB frames for the kernel 1:1 mapping independently of HUGETLBFS this can lead to incorrect storage accesses since the code can assume that we have a pointer to a page table instead of a pointer to a 1MB frame. Fix this by adding a pmd_large() primitive like other architectures have it already and remove all references to HUGETLBFS/HUGETLBPAGE from the code that walks kernel page tables. Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
648609e3 |
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20-Aug-2012 |
Gerald Schaefer <gerald.schaefer@linux.ibm.com> |
s390: enable large page support with CONFIG_DEBUG_PAGEALLOC So far, large page support was completely disabled with CONFIG_DEBUG_PAGEALLOC, although it would be sufficient if only the large page kernel mapping was disabled. This patch enables large page support with CONFIG_DEBUG_PAGEALLOC, while it prevents the large kernel mapping in that case. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
a53c8fab |
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20-Jul-2012 |
Heiko Carstens <hca@linux.ibm.com> |
s390/comments: unify copyright messages and remove file names Remove the file name from the comment at top of many files. In most cases the file name was wrong anyway, so it's rather pointless. Also unify the IBM copyright statement. We did have a lot of sightly different statements and wanted to change them one after another whenever a file gets touched. However that never happened. Instead people start to take the old/"wrong" statements to use as a template for new files. So unify all of them in one go. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
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f4815ac6 |
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23-May-2012 |
Heiko Carstens <hca@linux.ibm.com> |
s390/headers: replace __s390x__ with CONFIG_64BIT where possible Replace __s390x__ with CONFIG_64BIT in all places that are not exported to userspace or guarded with #ifdef __KERNEL__. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
60a0c68d |
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30-Oct-2011 |
Michael Holzheu <holzheu@linux.vnet.ibm.com> |
[S390] kdump backend code This patch provides the architecture specific part of the s390 kdump support. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
e5992f2e |
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24-Jul-2011 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[S390] kvm guest address space mapping Add code that allows KVM to control the virtual memory layout that is seen by a guest. The guest address space uses a second page table that shares the last level pte-tables with the process page table. If a page is unmapped from the process page table it is automatically unmapped from the guest page table as well. The guest address space mapping starts out empty, KVM can map any individual 1MB segments from the process virtual memory to any 1MB aligned location in the guest virtual memory. If a target segment in the process virtual memory does not exist or is unmapped while a guest mapping exists the desired target address is stored as an invalid segment table entry in the guest page table. The population of the guest page table is fault driven. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
b2fa47e6 |
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23-May-2011 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[S390] refactor page table functions for better pgste support Rework the architecture page table functions to access the bits in the page table extension array (pgste). There are a number of changes: 1) Fix missing pgste update if the attach_count for the mm is <= 1. 2) For every operation that affects the invalid bit in the pte or the rcp byte in the pgste the pcl lock needs to be acquired. The function pgste_get_lock gets the pcl lock and returns the current pgste value for a pte pointer. The function pgste_set_unlock stores the pgste and releases the lock. Between these two calls the bits in the pgste can be shuffled. 3) Define two software bits in the pte _PAGE_SWR and _PAGE_SWC to avoid calling SetPageDirty and SetPageReferenced from pgtable.h. If the host reference backup bit or the host change backup bit has been set the dirty/referenced state is transfered to the pte. The common code will pick up the state from the pte. 4) Add ptep_modify_prot_start and ptep_modify_prot_commit for mprotect. 5) Remove pgd_populate_kernel, pud_populate_kernel, pmd_populate_kernel pgd_clear_kernel, pud_clear_kernel, pmd_clear_kernel and ptep_invalidate. 6) Rename kvm_s390_test_and_clear_page_dirty to ptep_test_and_clear_user_dirty and add ptep_test_and_clear_user_young. 7) Define mm_exclusive() and mm_has_pgste() helper to improve readability. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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#
a1b200e2 |
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09-Aug-2010 |
Heiko Carstens <hca@linux.ibm.com> |
mm: provide init_mm mm_context initializer Provide an INIT_MM_CONTEXT intializer macro which can be used to statically initialize mm_struct:mm_context of init_mm. This way we can get rid of code which will do the initialization at run time (on s390). In addition the current code can be found at a place where it is not expected. So let's have a common initializer which architectures can use if needed. This is based on a patch from Suzuki Poulose. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Suzuki Poulose <suzuki@in.ibm.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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6af7eea2 |
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09-Apr-2010 |
Christian Borntraeger <borntraeger@de.ibm.com> |
[S390] s390: disable change bit override commit 6a985c6194017de2c062916ad1cd00dee0302c40 ([S390] s390: use change recording override for kernel mapping) deactivated the change bit recording for the kernel mapping to improve the performance. This works most of the time, but there are cases (e.g. kernel runs in home space, futex atomic compare xcmg) where we modify user memory with the kernel mapping instead of the user mapping. Instead of fixing these cases, this patch just deactivates change bit override to avoid future problems with other kernel code that might use the kernel mapping for user memory. CC: stable@kernel.org Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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5a0e3ad6 |
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24-Mar-2010 |
Tejun Heo <tj@kernel.org> |
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
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6a985c61 |
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06-Dec-2009 |
Christian Borntraeger <borntraeger@de.ibm.com> |
[S390] s390: use change recording override for kernel mapping We dont need the dirty bit if a write access is done via the kernel mapping. In that case SetPageDirty and friends are used anyway, no need to do that a second time. We can use the change-recording overide function for the kernel mapping, if available. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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50aa98ba |
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11-Sep-2009 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[S390] fix recursive locking on page_table_lock Suzuki Poulose reported the following recursive locking bug on s390: Here is the stack trace : (see Appendix I for more info) [<0000000000406ed6>] _spin_lock+0x52/0x94 [<0000000000103bde>] crst_table_free+0x14e/0x1a4 [<00000000001ba684>] __pmd_alloc+0x114/0x1ec [<00000000001be8d0>] handle_mm_fault+0x2cc/0xb80 [<0000000000407d62>] do_dat_exception+0x2b6/0x3a0 [<0000000000114f8c>] sysc_return+0x0/0x8 [<00000200001642b2>] 0x200001642b2 The page_table_lock is already acquired in __pmd_alloc (mm/memory.c) and it tries to populate the pud/pgd with a new pmd allocated. If another thread populates it before we get a chance, we free the pmd using pmd_free(). On s390x, pmd_free(even pud_free ) is #defined to crst_table_free(), which acquires the page_table_lock to protect the crst_table index updates. Hence this ends up in a recursive locking of the page_table_lock. The solution suggested by Dave Hansen is to use a new spin lock in the mmu context to protect the access to the crst_list and the pgtable_list. Reported-by: Suzuki Poulose <suzuki@in.ibm.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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ee0ddadd |
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10-Jun-2008 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] vmemmap: fix off-by-one bug. If a memory range is supposed to be added to the 1:1 mapping and it ends just below the maximum supported physical address it won't succeed. This is because a test doesn't consider that the end address is 1 smaller than start + size. Fix the comparison. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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67060d9c |
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30-May-2008 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] Fix section mismatch warnings. This fixes the last remaining section mismatch warnings in s390 architecture code. It reveals also a real bug introduced by... me with git commit 2069e978d5a6e7b45d58027e3de7f879b8c5e488 ("[S390] sparsemem vmemmap: initialize memmap.") Calling the generic vmemmap_alloc_block() function to get initialized memory is a nice idea, however that function is __meminit annotated and therefore the function might be gone if we try to call it later. This can happen if a DCSS segment gets added. So basically revert the patch and clear the memmap explicitly to fix the original bug. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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2069e978 |
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15-May-2008 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] sparsemem vmemmap: initialize memmap. Let's just use the generic vmmemmap_alloc_block() function which always returns initialized memory. Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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17f34580 |
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30-Apr-2008 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] Convert to SPARSEMEM & SPARSEMEM_VMEMMAP Convert s390 to SPARSEMEM and SPARSEMEM_VMEMMAP. We do a select of SPARSEMEM_VMEMMAP since it is configurable. This is because SPARSEMEM without SPARSEMEM_VMEMMAP gives us a hell of broken include dependencies that I don't want to fix. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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53492b1d |
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30-Apr-2008 |
Gerald Schaefer <gerald.schaefer@linux.ibm.com> |
[S390] System z large page support. This adds hugetlbfs support on System z, using both hardware large page support if available and software large page emulation on older hardware. Shared (large) page tables are implemented in software emulation mode, by using page->index of the first tail page from a compound large page to store page table information. Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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8fc63658 |
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30-Apr-2008 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] vmemmap: use clear_table to initialise page tables. Always use clear_table to initialise page tables. The overlapping memcpy is just a leftover of a previous version that wasn't fully converted to clear_table. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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5a216a20 |
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09-Feb-2008 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[S390] Add four level page tables for CONFIG_64BIT=y. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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146e4b3c |
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09-Feb-2008 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[S390] 1K/2K page table pages. This patch implements 1K/2K page table pages for s390. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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0189103c |
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05-Feb-2008 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] Remove BUILD_BUG_ON() in vmem code. Remove BUILD_BUG_ON() in vmem code since it causes build failures if the size of struct page increases. Instead calculate at compile time the address of the highest physical address that can be added to the 1:1 mapping. This supposed to fix a build failure with the page owner tracking leak detector patches as reported by akpm. page-owner-tracking-leak-detector-broken-on-s390.patch can be removed from -mm again when this is merged. Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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2bc89b5e |
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05-Feb-2008 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] Fix couple of section mismatches. Fix couple of section mismatches. And since we touch the code anyway change the IPL code to use C99 initializers. Cc: Michael Holzheu <holzheu@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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a2fd64d6 |
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26-Jan-2008 |
Christian Borntraeger <borntraeger@de.ibm.com> |
[S390] vmemmap: allocate struct pages before 1:1 mapping We have seen an oops in an OOM situation, where show_mem tried to access the struct page of a dcss segment. The vmemmap code has already created the 1:1 mapping but failed allocating the struct pages. In the OOM case, show_mem now walks the memory. It uses pfn_valid to detect if it may access the struct page. In the case described above, the mapping was established and pfn_valid returned true. As the struct pages were not allocated, the kernel oopsed. We have to ensure that we have created the struct pages, before we add a mapping pointing to the pages. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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9f4b0ba8 |
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26-Jan-2008 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] Get rid of HOLES_IN_ZONE requirement. Align everything to MAX_ORDER so we can get rid of the extra checks. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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5fd9c6e2 |
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26-Jan-2008 |
Christian Borntraeger <borntraeger@de.ibm.com> |
[S390] Change vmalloc defintions Currently the vmalloc area starts at a dynamic address depending on the memory size. There was also an 8MB security hole after the physical memory to catch out-of-bounds accesses. We can simplify the code by putting the vmalloc area explicitely at the top of the kernel mapping and setting the vmalloc size to a fixed value of 128MB/128GB for 31bit/64bit systems. Part of the vmalloc area will be used for the vmem_map. This leaves an area of 96MB/1GB for normal vmalloc allocations. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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190a1d72 |
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21-Oct-2007 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[S390] 4level-fixup cleanup Get independent from asm-generic/4level-fixup.h Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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3610cce8 |
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21-Oct-2007 |
Martin Schwidefsky <schwidefsky@de.ibm.com> |
[S390] Cleanup page table definitions. - De-confuse the defines for the address-space-control-elements and the segment/region table entries. - Create out of line functions for page table allocation / freeing. - Simplify get_shadow_xxx functions. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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e62133b4 |
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26-Jul-2007 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] Get rid of new section mismatch warnings. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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c1821c2e |
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05-Feb-2007 |
Gerald Schaefer <gerald.schaefer@linux.ibm.com> |
[S390] noexec protection This provides a noexec protection on s390 hardware. Our hardware does not have any bits left in the pte for a hw noexec bit, so this is a different approach using shadow page tables and a special addressing mode that allows separate address spaces for code and data. As a special feature of our "secondary-space" addressing mode, separate page tables can be specified for the translation of data addresses (storage operands) and instruction addresses. The shadow page table is used for the instruction addresses and the standard page table for the data addresses. The shadow page table is linked to the standard page table by a pointer in page->lru.next of the struct page corresponding to the page that contains the standard page table (since page->private is not really private with the pte_lock and the page table pages are not in the LRU list). Depending on the software bits of a pte, it is either inserted into both page tables or just into the standard (data) page table. Pages of a vma that does not have the VM_EXEC bit set get mapped only in the data address space. Any try to execute code on such a page will cause a page translation exception. The standard reaction to this is a SIGSEGV with two exceptions: the two system call opcodes 0x0a77 (sys_sigreturn) and 0x0aad (sys_rt_sigreturn) are allowed. They are stored by the kernel to the signal stack frame. Unfortunately, the signal return mechanism cannot be modified to use an SA_RESTORER because the exception unwinding code depends on the system call opcode stored behind the signal stack frame. This feature requires that user space is executed in secondary-space mode and the kernel in home-space mode, which means that the addressing modes need to be switched and that the noexec protection only works for user space. After switching the addressing modes, we cannot use the mvcp/mvcs instructions anymore to copy between kernel and user space. A new mvcos instruction has been added to the z9 EC/BC hardware which allows to copy between arbitrary address spaces, but on older hardware the page tables need to be walked manually. Signed-off-by: Gerald Schaefer <geraldsc@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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a2f3aa02 |
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11-Jan-2007 |
Dave Hansen <haveblue@us.ibm.com> |
[PATCH] Fix sparsemem on Cell Fix an oops experienced on the Cell architecture when init-time functions, early_*(), are called at runtime. It alters the call paths to make sure that the callers explicitly say whether the call is being made on behalf of a hotplug even, or happening at boot-time. It has been compile tested on ppc64, ia64, s390, i386 and x86_64. Acked-by: Arnd Bergmann <arndb@de.ibm.com> Signed-off-by: Dave Hansen <haveblue@us.ibm.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Acked-by: Andy Whitcroft <apw@shadowen.org> Cc: Christoph Lameter <clameter@engr.sgi.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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f4eb07c1 |
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08-Dec-2006 |
Heiko Carstens <hca@linux.ibm.com> |
[S390] Virtual memmap for s390. Virtual memmap support for s390. Inspired by the ia64 implementation. Unlike ia64 we need a mechanism which allows us to dynamically attach shared memory regions. These memory regions are accessed via the dcss device driver. dcss implements the 'direct_access' operation, which requires struct pages for every single shared page. Therefore this implementation provides an interface to attach/detach shared memory: int add_shared_memory(unsigned long start, unsigned long size); int remove_shared_memory(unsigned long start, unsigned long size); The purpose of the add_shared_memory function is to add the given memory range to the 1:1 mapping and to make sure that the corresponding range in the vmemmap is backed with physical pages. It also initialises the new struct pages. remove_shared_memory in turn only invalidates the page table entries in the 1:1 mapping. The page tables and the memory used for struct pages in the vmemmap are currently not freed. They will be reused when the next segment will be attached. Given that the maximum size of a shared memory region is 2GB and in addition all regions must reside below 2GB this is not too much of a restriction, but there is room for improvement. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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