mm: remove zap_page_range and create zap_vma_pages

zap_page_range was originally designed to unmap pages within an address
range that could span multiple vmas. While working on [1], it was
discovered that all callers of zap_page_range pass a range entirely within
a single vma. In addition, the mmu notification call within zap_page
range does not correctly handle ranges that span multiple vmas. When
crossing a vma boundary, a new mmu_notifier_range_init/end call pair with
the new vma should be made.

Instead of fixing zap_page_range, do the following:
- Create a new routine zap_vma_pages() that will remove all pages within
the passed vma. Most users of zap_page_range pass the entire vma and
can use this new routine.
- For callers of zap_page_range not passing the entire vma, instead call
zap_page_range_single().
- Remove zap_page_range.

[1] https://lore.kernel.org/linux-mm/20221114235507.294320-2-mike.kravetz@oracle.com/
Link: https://lkml.kernel.org/r/20230104002732.232573-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Suggested-by: Peter Xu <peterx@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com> [s390]
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

vdso/timens: Refactor copy-pasted find_timens_vvar_page() helper into one copy

find_timens_vvar_page() is not architecture-specific, as can be seen from
how all five per-architecture versions of it are the same.

(arm64, powerpc and riscv are exactly the same; x86 and s390 have two
characters difference inside a comment, less blank lines, and mark the
!CONFIG_TIME_NS version as inline.)

Refactor the five copies into a central copy in kernel/time/namespace.c.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20221130115320.2918447-1-jannh@google.com

powerpc: Provide syscall wrapper

Implement syscall wrapper as per s390, x86, arm64. When enabled
cause handlers to accept parameters from a stack frame rather than
from user scratch register state. This allows for user registers to be
safely cleared in order to reduce caller influence on speculation
within syscall routine. The wrapper is a macro that emits syscall
handler symbols that call into the target handler, obtaining its
parameters from a struct pt_regs on the stack.

As registers are already saved to the stack prior to calling
system_call_exception, it appears that this function is executed more
efficiently with the new stack-pointer convention than with parameters
passed by registers, avoiding the allocation of a stack frame for this
method. On a 32-bit system, we see >20% performance increases on the
null_syscall microbenchmark, and on a Power 8 the performance gains
amortise the cost of clearing and restoring registers which is
implemented at the end of this series, seeing final result of ~5.6%
performance improvement on null_syscall.

Syscalls are wrapped in this fashion on all platforms except for the
Cell processor as this commit does not provide SPU support. This can be
quickly fixed in a successive patch, but requires spu_sys_callback to
allocate a pt_regs structure to satisfy the wrapped calling convention.

Co-developed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmai.com>
[mpe: Make incompatible with COMPAT to retain clearing of high bits of args]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-22-rmclure@linux.ibm.com

powerpc: Use common syscall handler type

Cause syscall handlers to be typed as follows when called indirectly
throughout the kernel. This is to allow for better type checking.

typedef long (*syscall_fn)(unsigned long, unsigned long, unsigned long,
unsigned long, unsigned long, unsigned long);

Since both 32 and 64-bit abis allow for at least the first six
machine-word length parameters to a function to be passed by registers,
even handlers which admit fewer than six parameters may be viewed as
having the above type.

Coercing syscalls to syscall_fn requires a cast to void* to avoid
-Wcast-function-type.

Fixup comparisons in VDSO to avoid pointer-integer comparison. Introduce
explicit cast on systems with SPUs.

Signed-off-by: Rohan McLure <rmclure@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220921065605.1051927-19-rmclure@linux.ibm.com

powerpc: remove mmap linked list walks

Use the VMA iterator instead.

Link: https://lkml.kernel.org/r/20220906194824.2110408-34-Liam.Howlett@oracle.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Tested-by: Yu Zhao <yuzhao@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

powerpc/vdso: Don't map VDSO at a fixed address on PPC32

PPC64 removed default mapping address from VDSO in
commit 30d0b3682887 ("powerpc: Move 64bit VDSO to improve context
switch performance").

Do like PPC64 and let get_unmapped_area() place the VDSO mapping
at the address it wants, don't force a default address.

This allows randomisation of VDSO address.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/cba76f5a5b01fcc49415e632d92c11c1c5998cab.1660843877.git.christophe.leroy@csgroup.eu

powerpc: Remove asm/prom.h from all files that don't need it

Several files include asm/prom.h for no reason.

Clean it up.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Drop change to prom_parse.c as reported by lkp@intel.com]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7c9b8fda63dcf63e1b28f43e7ebdb95182cbc286.1646767214.git.christophe.leroy@csgroup.eu

powerpc/vdso: Add support for time namespaces

This patch adds the necessary glue to provide time namespaces.

Things are mainly copied from ARM64.

__arch_get_timens_vdso_data() calculates timens vdso data position
based on the vdso data position, knowing it is the next page in vvar.
This avoids having to redo the mflr/bcl/mflr/mtlr dance to locate
the page relative to running code position.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> # vDSO parts
Acked-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1a15495f80ec19a87b16cf874dbf7c3fa5ec40fe.1617209142.git.christophe.leroy@csgroup.eu

powerpc/vdso: Separate vvar vma from vdso

Since commit 511157ab641e ("powerpc/vdso: Move vdso datapage up front")
VVAR page is in front of the VDSO area. In result it breaks CRIU
(Checkpoint Restore In Userspace) [1], where CRIU expects that "[vdso]"
from /proc/../maps points at ELF/vdso image, rather than at VVAR data page.
Laurent made a patch to keep CRIU working (by reading aux vector).
But I think it still makes sence to separate two mappings into different
VMAs. It will also make ppc64 less "special" for userspace and as
a side-bonus will make VVAR page un-writable by debugger (which previously
would COW page and can be unexpected).

I opportunistically Cc stable on it: I understand that usually such
stuff isn't a stable material, but that will allow us in CRIU have
one workaround less that is needed just for one release (v5.11) on
one platform (ppc64), which we otherwise have to maintain.
I wouldn't go as far as to say that the commit 511157ab641e is ABI
regression as no other userspace got broken, but I'd really appreciate
if it gets backported to v5.11 after v5.12 is released, so as not
to complicate already non-simple CRIU-vdso code. Thanks!

[1]: https://github.com/checkpoint-restore/criu/issues/1417

Cc: stable@vger.kernel.org # v5.11
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> # vDSO parts.
Acked-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f401eb1ebc0bfc4d8f0e10dc8e525fd409eb68e2.1617209142.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove DBG()

DBG() is not used anymore. Remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e11a9b50e709f197bb3aa2ed1d80d2dee8714afc.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove vdso_ready

There is no way to get out of vdso_init() prematuraly anymore.

Remove vdso_ready as it will always be 1.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0e1e18c6329b848aa3edeeba76509b4d76182e7d.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove vdso_setup()

vdso_fixup_features() cannot fail anymore and that's
the only function called by vdso_setup().

vdso_setup() has become trivial and can be removed.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/11522eec6140f510a8c89c63cbb739277d097fdc.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove lib32_elfinfo and lib64_elfinfo

lib32_elfinfo and lib64_elfinfo are not used anymore, remove them.

Also remove vdso32_kbase and vdso64_kbase while removing the
last use.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/01ac65abf22f0428f8f764525a7d84459c54d806.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove symbol section information in struct lib32/64_elfinfo

The members related to the symbol section in struct lib32_elfinfo and
struct lib64_elfinfo are not used anymore, removed them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b779e5b7cc0354e2f87fd407fe5b02f4a8a73825.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove unused text member in struct lib32/64_elfinfo

The text member in struct lib32_elfinfo and struct lib64_elfinfo
is not used, remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f53dcc9bb1946a7854d15b34d03d3d2e2003848c.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove vdso_patches[] and associated functions

vdso_patches[] is now empty, remove it and remove
all functions that depends on it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/27d75debd6e4ddeaffe1d66ffed1e7526684a004.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove runtime generated sigtramp offsets

Signal trampoline offsets are now generated at buildtime.

Runtime generated offsets are not used anymore, remove them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7c192d35a437151837cf4c48aeccb42380d6daac.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove __kernel_datapage_offset

__kernel_datapage_offset is not used anymore, remove it.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ddb5c746bec4e1a026d7c85243213a1876ef844f.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove vdso32_pages and vdso64_pages

vdso32_pages and vdso64_pages are not used anymore.

Remove them.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/bce021f616cbaf39dfb5766cf7ef114adcb918d9.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Merge __kernel_sync_dicache_p5() into __kernel_sync_dicache()

__kernel_sync_dicache_p5() is an alternative to
__kernel_sync_dicache() when cpu has CPU_FTR_COHERENT_ICACHE

Remove this alternative function and merge
__kernel_sync_dicache_p5() into __kernel_sync_dicache() using
standard CPU feature fixup.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4c7dcc6544882761b2b0249d7a8ec2c3a8088cb5.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Use builtin symbols to locate fixup section

Add builtin symbols to locate fixup section and use them
instead of locating sections through elf headers at runtime.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2954526981859ca1ccfcfc7a7c4263920e9ddfcb.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Move vdso datapage up front

Move the vdso datapage in front of the VDSO area,
before vdso test.

This will allow to remove the __kernel_datapage_offset symbol
and simplify __get_datapage() in following patches.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b68c99b6e8ee0b1d99bfa4c7e34c359fc1bc1000.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Replace vdso_base by vdso

All other architectures but s390 use a void pointer named 'vdso'
to reference the VDSO mapping.

In a following patch, the VDSO data page will be put in front of
text, vdso_base will then not anymore point to VDSO text.

To avoid confusion between vdso_base and VDSO text, rename vdso_base
into vdso and make it a void __user *.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/8e6cefe474aa4ceba028abb729485cd46c140990.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Provide vdso_remap()

Provide vdso_remap() through _install_special_mapping() and
drop arch_remap().

This adds a test of the size and returns -EINVAL if the size
is not correct.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/373c66f768fa9cc8890f3b55462209a98c522326.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Move to _install_special_mapping() and remove arch_vma_name()

Copied from commit 2fea7f6c98f5 ("arm64: vdso: move to
_install_special_mapping and remove arch_vma_name").

Use the new _install_special_mapping() API added by
commit a62c34bd2a8a ("x86, mm: Improve _install_special_mapping
and fix x86 vdso naming") which obsolete install_special_mapping().

And remove arch_vma_name() as the name is handled by the new API.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: kernel test robot <lkp@intel.com>
[mpe: Squash fix to use PTR_ERR_OR_ZERO() from lkp]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e7e5dfe0f93234e31051f2a610b4b07f50b0082f.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Simplify arch_setup_additional_pages() exit

To simplify arch_setup_additional_pages() exit, rename
it __arch_setup_additional_pages() and create a caller
arch_setup_additional_pages() which does the locking.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/603c1d039d3f928ee95e547fcd2219fcf4c3b514.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Use VDSO size in arch_setup_additional_pages()

In arch_setup_additional_pages(), instead of using number of VDSO
pages and recalculate VDSO size, directly use the VDSO size.

As vdso_ready is set, vdso_pages can't be 0 so just remove the test.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4edfa548c3885a430b765335dc720105716e273f.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove unnecessary ifdefs in vdso_pagelist initialization

No need of all those #ifdefs around the pagelist initialisation,
use IS_ENABLED(), GCC will kick out unused static variables.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/f9333432e329b1fcbbbf846cb1cd4a1c4127a60b.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Refactor 32 bits and 64 bits pages setup

The setup of VDSO pages is identical for 32 bits VDSO and
64 bits VDSO.

Refactor that setup.

And use &vdsoXX_start which is synonym of vdsoXX_kbase.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/269ffb54c37fc1d46128f77d7a39f88ef4a9957d.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove NULL termination element in vdso_pagelist

No need of a NULL last element in pagelists, install_special_mapping()
knows how long the list is.

Remove that element.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e58d95ab859e3cbc9bae3c9ce2959e17d2864f5d.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Remove get_page() in vdso_pagelist initialization

Partly copied from commit 16fb1a9bec61 ("arm64: vdso: clean up
vdso_pagelist initialization").

No need to get_page() the vdso text/data - these are part of the
kernel image.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/9d14540bd10832b6c9519d74fb5728fdc4974b36.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Rename syscall_map_32/64 to simplify vdso_setup_syscall_map()

Today vdso_data structure has:
- syscall_map_32[] and syscall_map_64[] on PPC64
- syscall_map_32[] on PPC32

On PPC32, syscall_map_32[] is populated using sys_call_table[].

On PPC64, syscall_map_64[] is populated using sys_call_table[]
and syscal_map_32[] is populated using compat_sys_call_table[].

To simplify vdso_setup_syscall_map(),
- On PPC32 rename syscall_map_32[] into syscall_map[],
- On PPC64 rename syscall_map_64[] into syscall_map[],
- On PPC64 rename syscall_map_32[] into compat_syscall_map[].

That way, syscall_map[] gets populated using sys_call_table[] and
compat_syscall_map[] gets population using compat_sys_call_table[].

Also define an empty compat_syscall_map[] on PPC32 to avoid ifdefs.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/472734be0d9991eee320a06824219a5b2663736b.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Add missing includes and clean vdso_setup_syscall_map()

Instead of including extern references locally in
vdso_setup_syscall_map(), add the missing headers.

sys_ni_syscall() being a function, cast its address to
an unsigned long instead of declaring it as a fake
unsigned long object.

At the same time, remove a comment which paraphrases the
function name.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b4afedce748ed2858299ceab5ae29b52109263ef.1601197618.git.christophe.leroy@csgroup.eu

powerpc/vdso: Switch VDSO to generic C implementation.

With the C VDSO, the performance is slightly lower, but it is worth
it as it will ease maintenance and evolution, and also brings clocks
that are not supported with the ASM VDSO.

On an 8xx at 132 MHz, vdsotest with the ASM VDSO:
gettimeofday: vdso: 828 nsec/call
clock-getres-realtime-coarse: vdso: 391 nsec/call
clock-gettime-realtime-coarse: vdso: 614 nsec/call
clock-getres-realtime: vdso: 460 nsec/call
clock-gettime-realtime: vdso: 876 nsec/call
clock-getres-monotonic-coarse: vdso: 399 nsec/call
clock-gettime-monotonic-coarse: vdso: 691 nsec/call
clock-getres-monotonic: vdso: 460 nsec/call
clock-gettime-monotonic: vdso: 1026 nsec/call

On an 8xx at 132 MHz, vdsotest with the C VDSO:
gettimeofday: vdso: 955 nsec/call
clock-getres-realtime-coarse: vdso: 545 nsec/call
clock-gettime-realtime-coarse: vdso: 592 nsec/call
clock-getres-realtime: vdso: 545 nsec/call
clock-gettime-realtime: vdso: 941 nsec/call
clock-getres-monotonic-coarse: vdso: 545 nsec/call
clock-gettime-monotonic-coarse: vdso: 591 nsec/call
clock-getres-monotonic: vdso: 545 nsec/call
clock-gettime-monotonic: vdso: 940 nsec/call

It is even better for gettime with monotonic clocks.

Unsupported clocks with ASM VDSO:
clock-gettime-boottime: vdso: 3851 nsec/call
clock-gettime-tai: vdso: 3852 nsec/call
clock-gettime-monotonic-raw: vdso: 3396 nsec/call

Same clocks with C VDSO:
clock-gettime-tai: vdso: 941 nsec/call
clock-gettime-monotonic-raw: vdso: 1001 nsec/call
clock-gettime-monotonic-coarse: vdso: 591 nsec/call

On an 8321E at 333 MHz, vdsotest with the ASM VDSO:
gettimeofday: vdso: 220 nsec/call
clock-getres-realtime-coarse: vdso: 102 nsec/call
clock-gettime-realtime-coarse: vdso: 178 nsec/call
clock-getres-realtime: vdso: 129 nsec/call
clock-gettime-realtime: vdso: 235 nsec/call
clock-getres-monotonic-coarse: vdso: 105 nsec/call
clock-gettime-monotonic-coarse: vdso: 208 nsec/call
clock-getres-monotonic: vdso: 129 nsec/call
clock-gettime-monotonic: vdso: 274 nsec/call

On an 8321E at 333 MHz, vdsotest with the C VDSO:
gettimeofday: vdso: 272 nsec/call
clock-getres-realtime-coarse: vdso: 160 nsec/call
clock-gettime-realtime-coarse: vdso: 184 nsec/call
clock-getres-realtime: vdso: 166 nsec/call
clock-gettime-realtime: vdso: 281 nsec/call
clock-getres-monotonic-coarse: vdso: 160 nsec/call
clock-gettime-monotonic-coarse: vdso: 184 nsec/call
clock-getres-monotonic: vdso: 169 nsec/call
clock-gettime-monotonic: vdso: 275 nsec/call

On a Power9 Nimbus DD2.2 at 3.8GHz, with the ASM VDSO:
clock-gettime-monotonic: vdso: 35 nsec/call
clock-getres-monotonic: vdso: 16 nsec/call
clock-gettime-monotonic-coarse: vdso: 18 nsec/call
clock-getres-monotonic-coarse: vdso: 522 nsec/call
clock-gettime-monotonic-raw: vdso: 598 nsec/call
clock-getres-monotonic-raw: vdso: 520 nsec/call
clock-gettime-realtime: vdso: 34 nsec/call
clock-getres-realtime: vdso: 16 nsec/call
clock-gettime-realtime-coarse: vdso: 18 nsec/call
clock-getres-realtime-coarse: vdso: 517 nsec/call
getcpu: vdso: 8 nsec/call
gettimeofday: vdso: 25 nsec/call

And with the C VDSO:
clock-gettime-monotonic: vdso: 37 nsec/call
clock-getres-monotonic: vdso: 20 nsec/call
clock-gettime-monotonic-coarse: vdso: 21 nsec/call
clock-getres-monotonic-coarse: vdso: 19 nsec/call
clock-gettime-monotonic-raw: vdso: 38 nsec/call
clock-getres-monotonic-raw: vdso: 20 nsec/call
clock-gettime-realtime: vdso: 37 nsec/call
clock-getres-realtime: vdso: 20 nsec/call
clock-gettime-realtime-coarse: vdso: 20 nsec/call
clock-getres-realtime-coarse: vdso: 19 nsec/call
getcpu: vdso: 8 nsec/call
gettimeofday: vdso: 28 nsec/call

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201126131006.2431205-8-mpe@ellerman.id.au

powerpc/vdso: Fix vdso cpu truncation

The code in vdso_cpu_init that exposes the cpu and numa node to
userspace via SPRG_VDSO incorrctly masks the cpu to 12 bits. This means
that any kernel running on a box with more than 4096 threads (NR_CPUS
advertises a limit of of 8192 cpus) would expose userspace to two cpu
contexts running at the same time with the same cpu number.

Note: I'm not aware of any distro shipping a kernel with support for more
than 4096 threads today, nor of any system image that currently exceeds
4096 threads. Found via code browsing.

Fixes: 18ad51dd342a7eb09dbcd059d0b451b616d4dafc ("powerpc: Add VDSO version of getcpu")
Signed-off-by: Milton Miller <miltonm@us.ibm.com>
Signed-off-by: Anton Blanchard <anton@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200715233704.1352257-1-anton@ozlabs.org

mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.

The change is generated using coccinelle with the following rule:

// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .

@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.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>

powerpc/64: make buildable without CONFIG_COMPAT

There are numerous references to 32bit functions in generic and 64bit
code so ifdef them out.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e5619617020ef3a1f54f0c076e7d74cb9ec9f3bf.1584699455.git.msuchanek@suse.de

powerpc/vdso: remove deprecated VDS64_HAS_DESCRIPTORS references

The original 2005 patch that introduced the powerpc vdso, pre-git
("ppc64: Implement a vDSO and use it for signal trampoline") notes that:

... symbols exposed by the vDSO aren't "normal" function symbols, apps
can't be expected to link against them directly, the vDSO's are both
seen as if they were linked at 0 and the symbols just contain offsets
to the various functions. This is done on purpose to avoid a
relocation step (ppc64 functions normally have descriptors with abs
addresses in them). When glibc uses those functions, it's expected to
use it's own trampolines that know how to reach them.

Despite that explanation, there remains dead #ifdef
VDS64_HAS_DESCRIPTORS code-blocks that provide alternate function
definitions that setup function descriptors.

Since VDS64_HAS_DESCRIPTORS has been unused for all these years, we
might as well finally remove it from the codebase.

Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200224211848.26087-1-joe.lawrence@redhat.com

powerpc/vdso32: Don't read cache line size from the datapage on PPC32.

On PPC32, the cache lines have a fixed size known at build time.

Don't read it from the datapage.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/dfa7b35e27e01964fcda84bf1ed8b2b31cf93826.1575273217.git.christophe.leroy@c-s.fr

powerpc/32s: drop CPU_FTR_USE_RTC feature

CPU_FTR_USE_RTC feature only applies to powerpc601.

Drop this feature and replace it with tests on CONFIG_PPC_BOOK3S_601.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/170411e2360861f4a95c21faad43519a08bc4040.1566834712.git.christophe.leroy@c-s.fr

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

powerpc/vdso: don't clear PG_reserved

The VDSO is part of the kernel image and therefore the struct pages are
marked as reserved during boot.

As we install a special mapping, the actual struct pages will never be
exposed to MM via the page tables. We can therefore leave the pages
marked as reserved.

Link: http://lkml.kernel.org/r/20190114125903.24845-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> [powerpc]
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc: split compat syscall table out from native table

PowerPC uses a syscall table with native and compat calls
interleaved, which is a slightly simpler way to define two
matching tables.

As we move to having the tables generated, that advantage
is no longer important, but the interleaved table gets in
the way of using the same scripts as on the other archit-
ectures.

Split out a new compat_sys_call_table symbol that contains
all the compat calls, and leave the main table for the nat-
ive calls, to more closely match the method we use every-
where else.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Firoz Khan <firoz.khan@linaro.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc: remove unneeded inclusions of cpu_has_feature.h

Files not using cpu_has_feature() don't need cpu_has_feature.h

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

treewide: kzalloc() -> kcalloc()

The kzalloc() function has a 2-factor argument form, kcalloc(). This
patch replaces cases of:

kzalloc(a * b, gfp)

with:
kcalloc(a * b, gfp)

as well as handling cases of:

kzalloc(a * b * c, gfp)

with:

kzalloc(array3_size(a, b, c), gfp)

as it's slightly less ugly than:

kzalloc_array(array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

kzalloc(4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
kzalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
kzalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
kzalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
kzalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
kzalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_ID)
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_ID
+ COUNT_ID, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (COUNT_CONST)
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * COUNT_CONST
+ COUNT_CONST, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_ID)
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_ID
+ COUNT_ID, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (COUNT_CONST)
+ COUNT_CONST, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * COUNT_CONST
+ COUNT_CONST, sizeof(THING)
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

- kzalloc
+ kcalloc
(
- SIZE * COUNT
+ COUNT, SIZE
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
kzalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
kzalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
kzalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
kzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
kzalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
kzalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(
- (E1) * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * E3
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- (E1) * (E2) * (E3)
+ array3_size(E1, E2, E3)
, ...)
|
kzalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
kzalloc(sizeof(THING) * C2, ...)
|
kzalloc(sizeof(TYPE) * C2, ...)
|
kzalloc(C1 * C2 * C3, ...)
|
kzalloc(C1 * C2, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * (E2)
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(TYPE) * E2
+ E2, sizeof(TYPE)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * (E2)
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- sizeof(THING) * E2
+ E2, sizeof(THING)
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * E2
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- (E1) * (E2)
+ E1, E2
, ...)
|
- kzalloc
+ kcalloc
(
- E1 * E2
+ E1, E2
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>

powerpc: Use feature bit for RTC presence rather than timebase presence

All PowerPC CPUs other than the original PPC601 have a timebase
register rather than the "real-time clock" (RTC) register that the
PPC601 (and the original POWER and POWER2 CPUs) had. Currently
we have a CPU feature bit to indicate the presence of the timebase,
but it makes more sense to use a bit to indicate the unusual
situation rather than the common situation. This therefore defines
a CPU_FTR_USE_RTC bit in place of the CPU_FTR_USE_TB bit, and
arranges for it to be set on PPC601 systems.

Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/64: Clean up ppc64_caches using a struct per cache

We have two set of identical struct members for the I and D sides
and mostly identical bunches of code to parse the device-tree to
populate them. Instead make a ppc_cache_info structure with one
copy for I and one for D

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/64: Fix naming of cache block vs. cache line

In a number of places we called "cache line size" what is actually
the cache block size, which in the powerpc architecture, means the
effective size to use with cache management instructions (it can
be different from the actual cache line size).

We fix the naming across the board and properly retrieve both
pieces of information when available in the device-tree.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/vdso: Add missing include file

Some powerpc builds fail with the following buld error.

In file included from ./arch/powerpc/include/asm/mmu_context.h:11:0,
from arch/powerpc/kernel/vdso.c:28:
arch/powerpc/include/asm/cputhreads.h: In function 'get_tensr':
arch/powerpc/include/asm/cputhreads.h:101:2: error:
implicit declaration of function 'cpu_has_feature'

Fixes: b92a226e5284 ("powerpc: Move cpu_has_feature() to a separate file")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

vdso: make arch_setup_additional_pages wait for mmap_sem for write killable

most architectures are relying on mmap_sem for write in their
arch_setup_additional_pages. If the waiting task gets killed by the oom
killer it would block oom_reaper from asynchronous address space reclaim
and reduce the chances of timely OOM resolving. Wait for the lock in
the killable mode and return with EINTR if the task got killed while
waiting.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Andy Lutomirski <luto@amacapital.net> [x86 vdso]
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc: Standardise on NR_syscalls rather than __NR_syscalls.

Most architectures use NR_syscalls as the #define for the number of syscalls.

We use __NR_syscalls, and then define NR_syscalls as __NR_syscalls.

__NR_syscalls is not used outside arch code, whereas NR_syscalls is. So as
NR_syscalls must be defined and __NR_syscalls does not, replace __NR_syscalls
with NR_syscalls.

Signed-off-by: Rashmica Gupta <rashmicy@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/vdso: Disable building the 32-bit VDSO on little endian

The only little endian configuration we support is ppc64le. As such if
we're building little endian we don't need a 32-bit VDSO, because there
is no 32-bit userspace.

This patch is a fairly ugly mess of #ifdefs, but is the minimal logic
required to disable the 32-bit VDSO. We can hopefully clean up the
result in future with some further refactoring.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/vdso: Combine start/size variables

In vdso_fixup_features() we have start64/start32 and size64/size32, but
they have the same types, ie. void * and unsigned long.

They're only used to save the return value from find_sectionXX() for the
subsequent call to do_feature_fixups(), so there's no overlap in their
usage either.

So we can just consolidate them into start/size and avoid the
duplication.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc/vdso: Remove unused debug code

It's in the git history if we ever need it back.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

powerpc: Remove superfluous bootmem includes

Lots of places included bootmem.h even when not using bootmem.

Signed-off-by: Anton Blanchard <anton@samba.org>
Tested-by: Emil Medve <Emilian.Medve@Freescale.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arm64,ia64,ppc,s390,sh,tile,um,x86,mm: remove default gate area

The core mm code will provide a default gate area based on
FIXADDR_USER_START and FIXADDR_USER_END if
!defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).

This default is only useful for ia64. arm64, ppc, s390, sh, tile, 64-bit
UML, and x86_32 have their own code just to disable it. arm, 32-bit UML,
and x86_64 have gate areas, but they have their own implementations.

This gets rid of the default and moves the code into ia64.

This should save some code on architectures without a gate area: it's now
possible to inline the gate_area functions in the default case.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Acked-by: Nathan Lynch <nathan_lynch@mentor.com>
Acked-by: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [in principle]
Acked-by: Richard Weinberger <richard@nod.at> [for um]
Acked-by: Will Deacon <will.deacon@arm.com> [for arm64]
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Nathan Lynch <Nathan_Lynch@mentor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc/booke64: Use SPRG7 for VDSO

Previously SPRG3 was marked for use by both VDSO and critical
interrupts (though critical interrupts were not fully implemented).

In commit 8b64a9dfb091f1eca8b7e58da82f1e7d1d5fe0ad ("powerpc/booke64:
Use SPRG0/3 scratch for bolted TLB miss & crit int"), Mihai Caraman
made an attempt to resolve this conflict by restoring the VDSO value
early in the critical interrupt, but this has some issues:

- It's incompatible with EXCEPTION_COMMON which restores r13 from the
by-then-overwritten scratch (this cost me some debugging time).
- It forces critical exceptions to be a special case handled
differently from even machine check and debug level exceptions.
- It didn't occur to me that it was possible to make this work at all
(by doing a final "ld r13, PACA_EXCRIT+EX_R13(r13)") until after
I made (most of) this patch. :-)

It might be worth investigating using a load rather than SPRG on return
from all exceptions (except TLB misses where the scratch never leaves
the SPRG) -- it could save a few cycles. Until then, let's stick with
SPRG for all exceptions.

Since we cannot use SPRG4-7 for scratch without corrupting the state of
a KVM guest, move VDSO to SPRG7 on book3e. Since neither SPRG4-7 nor
critical interrupts exist on book3s, SPRG3 is still used for VDSO
there.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Cc: Mihai Caraman <mihai.caraman@freescale.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: kvm-ppc@vger.kernel.org

powerpc: Move local setup.h declarations to arch includes

Move the few declarations from arch/powerpc/kernel/setup.h
into arch/powerpc/include/asm/setup.h. This resolves a
sparse warning for arch/powerpc/mm/numa.c which defines
do_init_bootmem() but can't include the setup.h header
in the prior path.

Resolves:
arch/powerpc/mm/numa.c:998:13:
warning: symbol 'do_init_bootmem' was not declared.
Should it be static?

Signed-off-by: Robert C Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc: Delete __cpuinit usage from all users

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

This removes all the powerpc uses of the __cpuinit macros. There
are no __CPUINIT users in assembly files in powerpc.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Josh Boyer <jwboyer@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc: Add VDSO version of time

On 04/18/2013 07:38 PM, Anton Blanchard wrote:
> Since you are only reading one long you shouldn't need to check the
> update count and loop, you will always see a consistent value. The
> system call version of time() just does an unprotected load for example.

Fixed.

> With the above change and with Michael's comments covered (decent
> changelog entry and Signed-off-by):
>
> Acked-by: Anton Blanchard <anton@samba.org>

Thanks for the review, below the updated patch:

From: Adhemerval Zanella <azanella@linux.vnet.ibm.com>

This patch implement the time syscall as vDSO. The performance speedups
are:

Baseline PPC32: 380 nsec
Baseline PPC64: 350 nsec
vdso PPC32: 20 nsec
vsdo PPC64: 20 nsec

Tested on 64 bit build with both 32 bit and 64 bit userland.

Acked-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Adhemerval Zanella <azanella@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc: Restore VDSO information on critical exception om BookE

Critical exception on 64-bit booke uses user-visible SPRG3 as scratch.
Restore VDSO information in SPRG3 on exception prolog.

Use a common sprg3 field in PACA for all powerpc64 architectures.

Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc: Add VDSO version of getcpu

We have a request for a fast method of getting CPU and NUMA node IDs
from userspace. This patch implements a getcpu VDSO function,
similar to x86.

Ben suggested we use SPRG3 which is userspace readable. SPRG3 can be
modified by a KVM guest, so we save the SPRG3 value in the paca and
restore it when transitioning from the guest to the host.

I have a glibc patch that implements sched_getcpu on top of this.
Testing on a POWER7:

baseline: 538 cycles
vdso: 30 cycles

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Disintegrate asm/system.h for PowerPC

Disintegrate asm/system.h for PowerPC.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
cc: linuxppc-dev@lists.ozlabs.org

powerpc: Random little legacy iSeries removal tidy ups

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

coredump: remove VM_ALWAYSDUMP flag

The motivation for this patchset was that I was looking at a way for a
qemu-kvm process, to exclude the guest memory from its core dump, which
can be quite large. There are already a number of filter flags in
/proc/<pid>/coredump_filter, however, these allow one to specify 'types'
of kernel memory, not specific address ranges (which is needed in this
case).

Since there are no more vma flags available, the first patch eliminates
the need for the 'VM_ALWAYSDUMP' flag. The flag is used internally by
the kernel to mark vdso and vsyscall pages. However, it is simple
enough to check if a vma covers a vdso or vsyscall page without the need
for this flag.

The second patch then replaces the 'VM_ALWAYSDUMP' flag with a new
'VM_NODUMP' flag, which can be set by userspace using new madvise flags:
'MADV_DONTDUMP', and unset via 'MADV_DODUMP'. The core dump filters
continue to work the same as before unless 'MADV_DONTDUMP' is set on the
region.

The qemu code which implements this features is at:

http://people.redhat.com/~jbaron/qemu-dump/qemu-dump.patch

In my testing the qemu core dump shrunk from 383MB -> 13MB with this
patch.

I also believe that the 'MADV_DONTDUMP' flag might be useful for
security sensitive apps, which might want to select which areas are
dumped.

This patch:

The VM_ALWAYSDUMP flag is currently used by the coredump code to
indicate that a vma is part of a vsyscall or vdso section. However, we
can determine if a vma is in one these sections by checking it against
the gate_vma and checking for a non-NULL return value from
arch_vma_name(). Thus, freeing a valuable vma bit.

Signed-off-by: Jason Baron <jbaron@redhat.com>
Acked-by: Roland McGrath <roland@hack.frob.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc: remove non-required uses of include <linux/module.h>

None of the files touched here are modules, and they are not
exporting any symbols either -- so there is no need to be including
the module.h. Builds of all the files remains successful.

Even kernel/module.c does not need to include it, since it includes
linux/moduleloader.h instead.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

mm: arch: rename in_gate_area_no_task to in_gate_area_no_mm

Now that gate vma's are referenced with respect to a particular mm and not a
particular task it only makes sense to propagate the change to this predicate as
well.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: Michel Lespinasse <walken@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

mm: arch: make in_gate_area take an mm_struct instead of a task_struct

Morally, the question of whether an address lies in a gate vma should be asked
with respect to an mm, not a particular task. Moreover, dropping the dependency
on task_struct will help make existing and future operations on mm's more
flexible and convenient.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: Michel Lespinasse <walken@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

mm: arch: make get_gate_vma take an mm_struct instead of a task_struct

Morally, the presence of a gate vma is more an attribute of a particular mm than
a particular task. Moreover, dropping the dependency on task_struct will help
make both existing and future operations on mm's more flexible and convenient.

Signed-off-by: Stephen Wilson <wilsons@start.ca>
Reviewed-by: Michel Lespinasse <walken@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

powerpc: Use is_32bit_task() helper to test 32-bit binary

This patch removes all explicit tests for the TIF_32BIT flag

Signed-off-by: Denis Kirjanov <dkirjanov@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

lmb: rename to memblock

via following scripts

FILES=$(find * -type f | grep -vE 'oprofile|[^K]config')

sed -i \
-e 's/lmb/memblock/g' \
-e 's/LMB/MEMBLOCK/g' \
$FILES

for N in $(find . -name lmb.[ch]); do
M=$(echo $N | sed 's/lmb/memblock/g')
mv $N $M
done

and remove some wrong change like lmbench and dlmb etc.

also move memblock.c from lib/ to mm/

Suggested-by: Ingo Molnar <mingo@elte.hu>
Acked-by: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

tree-wide: fix a very frequent spelling mistake

something-bility is spelled as something-blity
so a grep for 'blit' would find these lines

this is so trivial that I didn't split it by subsystem / copy
additional maintainers - all changes are to comments
The only purpose is to get fewer false positives when grepping
around the kernel sources.

Signed-off-by: Dirk Hohndel <hohndel@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

powerpc: Align vDSO base address

The ABI specifies a 64K alignment, we need to map the vDSO accordingly

Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

powerpc/perf_counter: Fix vdso detection

perf_counter uses arch_vma_name() to detect a vdso region which in turn uses
current->mm->context.vdso_base. We need to initialise this before doing
the mmap or else we fail to detect the vdso.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Use macros for .data.page_aligned section.

This patch changes the remaining direct references to
.data.page_aligned in C and assembly code to use the macros in
include/linux/linkage.h.

Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

powerpc: Move 64bit VDSO to improve context switch performance

On 64bit applications the VDSO is the only thing in segment 0. Since the VDSO
is position independent we can remove the hint and let get_unmapped_area pick
an area. This will mean the vdso will be near other mmaps and will share
an SLB entry:

10000000-10001000 r-xp 00000000 08:06 5778459 /root/context_switch_64
10010000-10011000 r--p 00000000 08:06 5778459 /root/context_switch_64
10011000-10012000 rw-p 00001000 08:06 5778459 /root/context_switch_64
fffa92ae000-fffa92b0000 rw-p 00000000 00:00 0
fffa92b0000-fffa9453000 r-xp 00000000 08:06 4334051 /lib64/power6/libc-2.9.so
fffa9453000-fffa9462000 ---p 001a3000 08:06 4334051 /lib64/power6/libc-2.9.so
fffa9462000-fffa9466000 r--p 001a2000 08:06 4334051 /lib64/power6/libc-2.9.so
fffa9466000-fffa947c000 rw-p 001a6000 08:06 4334051 /lib64/power6/libc-2.9.so
fffa947c000-fffa9480000 rw-p 00000000 00:00 0
fffa9480000-fffa94a8000 r-xp 00000000 08:06 4333852 /lib64/ld-2.9.so
fffa94b3000-fffa94b4000 rw-p 00000000 00:00 0

fffa94b4000-fffa94b7000 r-xp 00000000 00:00 0 [vdso] <----- here I am

fffa94b7000-fffa94b8000 r--p 00027000 08:06 4333852 /lib64/ld-2.9.so
fffa94b8000-fffa94bb000 rw-p 00028000 08:06 4333852 /lib64/ld-2.9.so
fffa94bb000-fffa94bc000 rw-p 00000000 00:00 0
fffe4c10000-fffe4c25000 rw-p 00000000 00:00 0 [stack]

On a microbenchmark that bounces a token between two 64bit processes over pipes
and calls gettimeofday each iteration (to access the VDSO), our context switch
rate goes from 268k to 277k ctx switches/sec (tested on a 4GHz POWER6).

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

[S390] arch_setup_additional_pages arguments

arch_setup_additional_pages currently gets two arguments, the binary
format descripton and an indication if the process uses an executable
stack or not. The second argument is not used by anybody, it could
be removed without replacement.

What actually does make sense is to pass an indication if the process
uses the elf interpreter or not. The glibc code will not use anything
from the vdso if the process does not use the dynamic linker, so for
statically linked binaries the architecture backend can choose not
to map the vdso.

Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

powerpc/mm: Introduce MMU features

We're soon running out of CPU features and I need to add some new
ones for various MMU related bits, so this patch separates the MMU
features from the CPU features. I moved over the 32-bit MMU related
ones, added base features for MMU type families, but didn't move
over any 64-bit only feature yet.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

powerpc: Remove use of CONFIG_PPC_MERGE

Now that arch/ppc is gone and CONFIG_PPC_MERGE is always set, remove
the dead code associated with !CONFIG_PPC_MERGE from arch/powerpc
and include/asm-powerpc.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

powerpc: Fixup lwsync at runtime

To allow for a single kernel image on e500 v1/v2/mc we need to fixup lwsync
at runtime. On e500v1/v2 lwsync causes an illop so we need to patch up
the code. We default to 'sync' since that is always safe and if the cpu
is capable we will replace 'sync' with 'lwsync'.

We introduce CPU_FTR_LWSYNC as a way to determine at runtime if this is
needed. This flag could be moved elsewhere since we dont really use it
for the normal CPU_FTR purpose.

Finally we only store the relative offset in the fixup section to keep it
as small as possible rather than using a full fixup_entry.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

Reinstate ZERO_PAGE optimization in 'get_user_pages()' and fix XIP

KAMEZAWA Hiroyuki and Oleg Nesterov point out that since the commit
557ed1fa2620dc119adb86b34c614e152a629a80 ("remove ZERO_PAGE") removed
the ZERO_PAGE from the VM mappings, any users of get_user_pages() will
generally now populate the VM with real empty pages needlessly.

We used to get the ZERO_PAGE when we did the "handle_mm_fault()", but
since fault handling no longer uses ZERO_PAGE for new anonymous pages,
we now need to handle that special case in follow_page() instead.

In particular, the removal of ZERO_PAGE effectively removed the core
file writing optimization where we would skip writing pages that had not
been populated at all, and increased memory pressure a lot by allocating
all those useless newly zeroed pages.

This reinstates the optimization by making the unmapped PTE case the
same as for a non-existent page table, which already did this correctly.

While at it, this also fixes the XIP case for follow_page(), where the
caller could not differentiate between the case of a page that simply
could not be used (because it had no "struct page" associated with it)
and a page that just wasn't mapped.

We do that by simply returning an error pointer for pages that could not
be turned into a "struct page *". The error is arbitrarily picked to be
EFAULT, since that was what get_user_pages() already used for the
equivalent IO-mapped page case.

[ Also removed an impossible test for pte_offset_map_lock() failing:
that's not how that function works ]

Acked-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Nick Piggin <npiggin@suse.de>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[POWERPC] vdso_do_func_patch{32,64}() must be __init

This fixes the following section mismatches:

<-- snip -->

...
WARNING: vmlinux.o(.text+0xe49c): Section mismatch in reference from the function .vdso_do_func_patch64() to the function .init.text:.find_symbol64()
WARNING: vmlinux.o(.text+0xe4d0): Section mismatch in reference from the function .vdso_do_func_patch64() to the function .init.text:.find_symbol64()
WARNING: vmlinux.o(.text+0xe56c): Section mismatch in reference from the function .vdso_do_func_patch32() to the function .init.text:.find_symbol32()
WARNING: vmlinux.o(.text+0xe5a0): Section mismatch in reference from the function .vdso_do_func_patch32() to the function .init.text:.find_symbol32()
...

<-- snip -->

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[LIB]: Make PowerPC LMB code generic so sparc64 can use it too.

Signed-off-by: David S. Miller <davem@davemloft.net>

[POWERPC] vdso: Fixes for cache block sizes

The current VDSO implementation is hardcoded to 128 byte cache blocks,
which are only used on IBM's 64-bit processors.

Convert it to get the cache block sizes out of vdso_data instead,
similar to how the ppc64 in-kernel cache flush does it.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] Disable vDSO support for ARCH=ppc where it's not implemented

Signed-off-by: Wolfgang Denk <wd@denx.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] Don't expose clock vDSO functions when CPU has no timebase

We forgot to remove the clock_gettime, clock_getres and get_tbfreq vDSO
calls on CPUs that have no timebase such as 601 or 403 (old CPUs that have
different mechanisms and for which the vDSO code will not work properly).
This fixes it.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] Fix VDSO compile warning

Maybe the type should have been char[] instead of __u8[]
in the first place, but this will do.

Signed-off-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

header cleaning: don't include smp_lock.h when not used

Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.

Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[POWERPC] Fix vDSO page count calculation

The recent vDSO consolidation patches broke powerpc due to a mistake
in the definition of MAXPAGES constants. This fixes it by moving to
a dynamically allocated array of pages instead as I don't like much
hard coded size limits. Also move the vdso initialisation to an initcall
since it doesn't really need to be done -that- early.

Applogies for not catching the breakage earlier, Roland _did_ CC me on
his patches a while ago, I got busy with other things and forgot to test
them.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[PATCH] powerpc vDSO: use install_special_mapping

This patch uses install_special_mapping for the powerpc vDSO setup,
consolidating duplicated code.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[PATCH] powerpc vDSO: use VM_ALWAYSDUMP

This patch fixes core dumps to include the vDSO vma, which is left out now.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[PATCH] slab: remove SLAB_KERNEL

SLAB_KERNEL is an alias of GFP_KERNEL.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[POWERPC] Support feature fixups in vdso's

This patch reworks the feature fixup mecanism so vdso's can be fixed up.
The main issue was that the construct:

.long label (or .llong on 64 bits)

will not work in the case of a shared library like the vdso. It will
generate an empty placeholder in the fixup table along with a reloc,
which is not something we can deal with in the vdso.

The idea here (thanks Alan Modra !) is to instead use something like:

1:
.long label - 1b

That is, the feature fixup tables no longer contain addresses of bits of
code to patch, but offsets of such code from the fixup table entry
itself. That is properly resolved by ld when building the .so's. I've
modified the fixup mecanism generically to use that method for the rest
of the kernel as well.

Another trick is that the 32 bits vDSO included in the 64 bits kernel
need to have a table in the 64 bits format. However, gas does not
support 32 bits code with a statement of the form:

.llong label - 1b (Or even just .llong label)

That is, it cannot emit the right fixup/relocation for the linker to use
to assign a 32 bits address to an .llong field. Thus, in the specific
case of the 32 bits vdso built as part of the 64 bits kernel, we are
using a modified macro that generates:

.long 0xffffffff
.llong label - 1b

Note that is assumes that the value is negative which is enforced by
the .lds (those offsets are always negative as the .text is always
before the fixup table and gas doesn't support emiting the reloc the
other way around).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

Remove obsolete #include <linux/config.h>

Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

[PATCH] powerpc vdso updates

This patch cleans up some locking & error handling in the ppc vdso and
moves the vdso base pointer from the thread struct to the mm context
where it more logically belongs. It brings the powerpc implementation
closer to Ingo's new x86 one and also adds an arch_vma_name() function
allowing to print [vsdo] in /proc/<pid>/maps if Ingo's x86 vdso patch is
also applied.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[PATCH] powerpc: Kill _machine and hard-coded platform numbers

This removes statically assigned platform numbers and reworks the
powerpc platform probe code to use a better mechanism. With this,
board support files can simply declare a new machine type with a
macro, and implement a probe() function that uses the flattened
device-tree to detect if they apply for a given machine.

We now have a machine_is() macro that replaces the comparisons of
_machine with the various PLATFORM_* constants. This commit also
changes various drivers to use the new macro instead of looking at
_machine.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

[PATCH] Add mm->task_size and fix powerpc vdso

This patch adds mm->task_size to keep track of the task size of a given mm
and uses that to fix the powerpc vdso so that it uses the mm task size to
decide what pages to fault in instead of the current thread flags (which
broke when ptracing).

(akpm: I expect that mm_struct.task_size will become the way in which we
finally sort out the confusion between 32-bit processes and 32-bit mm's. It
may need tweaks, but at this stage this patch is powerpc-only.)

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] powerpc: trivial: modify comments to refer to new location of files

This patch removes all self references and fixes references to files
in the now defunct arch/ppc64 tree. I think this accomplises
everything wanted, though there might be a few references I missed.

Signed-off-by: Jon Mason <jdmason@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

mm: re-architect the VM_UNPAGED logic

This replaces the (in my opinion horrible) VM_UNMAPPED logic with very
explicit support for a "remapped page range" aka VM_PFNMAP. It allows a
VM area to contain an arbitrary range of page table entries that the VM
never touches, and never considers to be normal pages.

Any user of "remap_pfn_range()" automatically gets this new
functionality, and doesn't even have to mark the pages reserved or
indeed mark them any other way. It just works. As a side effect, doing
mmap() on /dev/mem works for arbitrary ranges.

Sparc update from David in the next commit.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] unpaged: VM_UNPAGED

Although we tend to associate VM_RESERVED with remap_pfn_range, quite a few
drivers set VM_RESERVED on areas which are then populated by nopage. The
PageReserved removal in 2.6.15-rc1 changed VM_RESERVED not to free pages in
zap_pte_range, without changing those drivers not to set it: so their pages
just leak away.

Let's not change miscellaneous drivers now: introduce VM_UNPAGED at the core,
to flag the special areas where the ptes may have no struct page, or if they
have then it's not to be touched. Replace most instances of VM_RESERVED in
core mm by VM_UNPAGED. Force it on in remap_pfn_range, and the sparc and
sparc64 io_remap_pfn_range.

Revert addition of VM_RESERVED to powerpc vdso, it's not needed there. Is it
needed anywhere? It still governs the mm->reserved_vm statistic, and special
vmas not to be merged, and areas not to be core dumped; but could probably be
eliminated later (the drivers are probably specifying it because in 2.4 it
kept swapout off the vma, but in 2.6 we work from the LRU, which these pages
don't get on).

Use the VM_SHM slot for VM_UNPAGED, and define VM_SHM to 0: it serves no
purpose whatsoever, and should be removed from drivers when we clean up.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Acked-by: William Irwin <wli@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel

This patch moves the vdso's to arch/powerpc, adds support for the 32
bits vdso to the 32 bits kernel, rename systemcfg (finally !), and adds
some new (still untested) routines to both vdso's: clock_gettime() with
support for CLOCK_REALTIME and CLOCK_MONOTONIC, clock_getres() (same
clocks) and get_tbfreq() for glibc to retreive the timebase frequency.

Tom,Steve: The implementation of get_tbfreq() I've done for 32 bits
returns a long long (r3, r4) not a long. This is such that if we ever
add support for >4Ghz timebases on ppc32, the userland interface won't
have to change.

I have tested gettimeofday() using some glibc patches in both ppc32 and
ppc64 kernels using 32 bits userland (I haven't had a chance to test a
64 bits userland yet, but the implementation didn't change and was
tested earlier). I haven't tested yet the new functions.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>