powerpc/kexec: split CONFIG_KEXEC_FILE and CONFIG_CRASH_DUMP

CONFIG_KEXEC_FILE does not have to select CONFIG_CRASH_DUMP. Move
some code under CONFIG_CRASH_DUMP to support CONFIG_KEXEC_FILE and
!CONFIG_CRASH_DUMP case.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240226103010.589537-3-hbathini@linux.ibm.com

kexec_file, power: print out debugging message if required

Then when specifying '-d' for kexec_file_load interface, loaded locations
of kernel/initrd/cmdline etc can be printed out to help debug.

Here replace pr_debug() with the newly added kexec_dprintk() in kexec_file
loading related codes.

Link: https://lkml.kernel.org/r/20231213055747.61826-7-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Conor Dooley <conor@kernel.org>
Cc: Joe Perches <joe@perches.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

powerpc: Annotate endianness of various variables and functions

Sparse reports several endianness warnings on variables and functions
that are consistently treated as big endian. There are no
multi-endianness shenanigans going on here so fix these low hanging
fruit up in one patch.

All changes are just type annotations; no endianness switching
operations are introduced by this patch.

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231011053711.93427-7-bgray@linux.ibm.com

powerpc/kexec_file: add missing of_node_put

for_each_node_with_property performs an of_node_get on each
iteration, so a break out of the loop requires an
of_node_put.

This was done using the Coccinelle semantic patch
iterators/for_each_child.cocci

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230907095521.14053-7-Julia.Lawall@inria.fr

powerpc: Move DMA64_PROPNAME define to a header

Avoid redefining the same value in multiple source.

Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230817162411.429-1-msuchanek@suse.de

powerpc/kexec: fix minor typo

Function name in the descriptor was not correct.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202307251721.bUGcsCeQ-lkp@intel.com/
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230725132759.53975-1-ldufour@linux.ibm.com

powerpc: Explicitly include correct DT includes

The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
[mpe: Fixup maple/setup.c which needs platform_device]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230724210247.778034-1-robh@kernel.org

powerpc/kexec_file: print error string on usable memory property update failure

Print the FDT error description along with the error message if failed
to set the "linux,drconf-usable-memory" property in the kdump kernel's
FDT.

Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221216122708.182154-1-sourabhjain@linux.ibm.com

powerpc/pseries: Pass PLPKS password on kexec

Before interacting with the PLPKS, we ask the hypervisor to generate a
password for the current boot, which is then required for most further
PLPKS operations.

If we kexec into a new kernel, the new kernel will try and fail to
generate a new password, as the password has already been set.

Pass the password through to the new kernel via the device tree, in
/chosen/ibm,plpks-pw. Check for the presence of this property before
trying to generate a new password - if it exists, use the existing
password and remove it from the device tree.

This only works with the kexec_file_load() syscall, not the older
kexec_load() syscall, however if you're using Secure Boot then you want
to be using kexec_file_load() anyway.

Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230210080401.345462-24-ajd@linux.ibm.com

powerpc/kexec_file: fix implicit decl error

kexec (PPC64) code calls memory_hotplug_max(). Add the header
declaration for it from <asm/mmzone.h>. Using <linux/mmzone.h> does not
work since the #include for <asm/mmzone.h> depends on CONFIG_NUMA=y,
which is not always set.

Fixes this build error/warning:

arch/powerpc/kexec/file_load_64.c: In function 'kexec_extra_fdt_size_ppc64':
arch/powerpc/kexec/file_load_64.c:993:33: error: implicit declaration of function 'memory_hotplug_max'
993 | usm_entries = ((memory_hotplug_max() / drmem_lmb_size()) +
| ^~~~~~~~~~~~~~~~~~

Fixes: fc546faa5595 ("powerpc/kexec_file: Count hot-pluggable memory in FDT estimate")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230204172206.7662-1-rdunlap@infradead.org

powerpc/kexec_file: Count hot-pluggable memory in FDT estimate

On Systems where online memory is lesser compared to max memory, the
kexec_file_load system call may fail to load the kdump kernel with the
below errors:

"Failed to update fdt with linux,drconf-usable-memory property"
"Error setting up usable-memory property for kdump kernel"

This happens because the size estimation for usable memory properties
for the kdump kernel's FDT is based on the online memory whereas the
usable memory properties include max memory. In short, the hot-pluggable
memory is not accounted for while estimating the size of the usable
memory properties.

The issue is addressed by calculating usable memory property size using
max hotplug address instead of the last online memory address.

Fixes: 2377c92e37fe ("powerpc/kexec_file: fix FDT size estimation for kdump kernel")
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230131030615.729894-1-sourabhjain@linux.ibm.com

powerpc/kexec_file: Fix division by zero in extra size estimation

In kexec_extra_fdt_size_ppc64() there's logic to estimate how much
extra space will be needed in the device tree for some memory related
properties.

That logic uses the size of RAM divided by drmem_lmb_size() to do the
estimation. However drmem_lmb_size() can be zero if the machine has no
hotpluggable memory configured, which is the case when booting with qemu
and no maxmem=x parameter is passed (the default).

The division by zero is reported by UBSAN, and can also lead to an
overflow and a warning from kvmalloc, and kdump kernel loading fails:

WARNING: CPU: 0 PID: 133 at mm/util.c:596 kvmalloc_node+0x15c/0x160
Modules linked in:
CPU: 0 PID: 133 Comm: kexec Not tainted 6.2.0-rc5-03455-g07358bd97810 #223
Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1200 0xf000005 of:SLOF,git-dd0dca pSeries
NIP: c00000000041ff4c LR: c00000000041fe58 CTR: 0000000000000000
REGS: c0000000096ef750 TRAP: 0700 Not tainted (6.2.0-rc5-03455-g07358bd97810)
MSR: 800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 24248242 XER: 2004011e
CFAR: c00000000041fed0 IRQMASK: 0
...
NIP kvmalloc_node+0x15c/0x160
LR kvmalloc_node+0x68/0x160
Call Trace:
kvmalloc_node+0x68/0x160 (unreliable)
of_kexec_alloc_and_setup_fdt+0xb8/0x7d0
elf64_load+0x25c/0x4a0
kexec_image_load_default+0x58/0x80
sys_kexec_file_load+0x5c0/0x920
system_call_exception+0x128/0x330
system_call_vectored_common+0x15c/0x2ec

To fix it, skip the calculation if drmem_lmb_size() is zero.

Fixes: 2377c92e37fe ("powerpc/kexec_file: fix FDT size estimation for kdump kernel")
Cc: stable@vger.kernel.org # v5.12+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230130014707.541110-1-mpe@ellerman.id.au

powerpc: Take in account addition CPU node when building kexec FDT

On a system with a large number of CPUs, the creation of the FDT for a
kexec kernel may fail because the allocated FDT is not large enough.

When this happens, such a message is displayed on the console:

Unable to add ibm,processor-vadd-size property: FDT_ERR_NOSPACE

The property's name may change depending when the buffer overwrite is
detected.

Obviously the created FDT is missing information, and it is expected
that system dump or kexec kernel failed to run properly.

When the FDT is allocated, the size of the FDT the kernel received at
boot time is used and an extra size can be applied. Currently, only
memory added after boot time is taken in account, not the CPU nodes.

The extra size should take in account these additional CPU nodes and
compute the required extra space. To achieve that, the size of a CPU
node, including its subnode is computed once and multiplied by the
number of additional CPU nodes.

The assumption is that the size of the CPU node is _same_ for all the
node, the only variable part should be the name "PowerPC,POWERxx@##"
where "##" may vary a little.

Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
[mpe: Don't shadow function name w/variable, minor coding style changes]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221110180619.15796-3-ldufour@linux.ibm.com

kexec: replace crash_mem_range with range

We already have struct range, so just use it.

Link: https://lkml.kernel.org/r/20220929042936.22012-4-bhe@redhat.com
Signed-off-by: Li Chen <lchen@ambarella.com>
Signed-off-by: Baoquan He <bhe@redhat.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Chen Lifu <chenlifu@huawei.com>
Cc: "Eric W . Biederman" <ebiederm@xmission.com>
Cc: Jianglei Nie <niejianglei2021@163.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: ye xingchen <ye.xingchen@zte.com.cn>
Cc: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

powerpc/kexec: Fix build failure from uninitialised variable

clang 14 won't build because ret is uninitialised and can be returned if
both prop and fdtprop are NULL. Drop the ret variable and return an
error in that failure case.

Fixes: b1fc44eaa9ba ("pseries/iommu/ddw: Fix kdump to work in absence of ibm,dma-window")
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220810054331.373761-1-ruscur@russell.cc

powerpc/64e: Fix kexec build error

When building ppc64_book3e_allmodconfig the build fails with:

arch/powerpc/kexec/file_load_64.c:1063:14: error: implicit declaration of function ‘firmware_has_feature’
1063 | if (!firmware_has_feature(FW_FEATURE_LPAR))
| ^~~~~~~~~~~~~~~~~~~~

Add a direct include of asm/firmware.h to fix the error.

Fixes: b1fc44eaa9ba ("pseries/iommu/ddw: Fix kdump to work in absence of ibm,dma-window")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220803063152.1249270-1-mpe@ellerman.id.au

pseries/iommu/ddw: Fix kdump to work in absence of ibm,dma-window

The pseries platform uses 32bit default DMA window (always 4K pages) and
optional 64bit DMA window available via DDW ("Dynamic DMA Windows"),
64K or 2M pages. For ages the default one was not removed and a huge
window was created in addition. Things changed with SRIOV-enabled
PowerVM which creates a default-and-bigger DMA window in 64bit space
(still using 4K pages) for IOV VFs so certain OSes do not need to use
the DDW API in order to utilize all available TCE budget.

Linux on the other hand removes the default window and creates a bigger
one (with more TCEs or/and a bigger page size - 64K/2M) in a bid to map
the entire RAM, and if the new window size is smaller than that - it
still uses this new bigger window. The result is that the default window
is removed but the "ibm,dma-window" property is not.

When kdump is invoked, the existing code tries reusing the existing 64bit
DMA window which location and parameters are stored in the device tree but
this fails as the new property does not make it to the kdump device tree
blob. So the code falls back to the default window which does not exist
anymore although the device tree says that it does. The result of that
is that PCI devices become unusable and cannot be used for kdumping.

This preserves the DMA64 and DIRECT64 properties in the device tree blob
for the crash kernel. Since the crash kernel setup is done after device
drivers are loaded and probed, the proper DMA config is stored at least
for boot time devices.

Because DDW window is optional and the code configures the default window
first, the existing code creates an IOMMU table descriptor for
the non-existing default DMA window. It is harmless for kdump as it does
not touch the actual window (only reads what is mapped and marks those IO
pages as used) but it is bad for kexec which clears it thinking it is
a smaller default window rather than a bigger DDW window.

This removes the "ibm,dma-window" property from the device tree after
a bigger window is created and the crash kernel setup picks it up.

Fixes: 381ceda88c4c ("powerpc/pseries/iommu: Make use of DDW for indirect mapping")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220629060614.1680476-1-aik@ozlabs.ru

powerpc/kexec_file: Add of_node_put() before goto

Fix following coccicheck warning:
./arch/powerpc/kexec/file_load_64.c:698:1-22: WARNING: Function
for_each_node_by_type should have of_node_put() before goto

Early exits from for_each_node_by_type should decrement the
node reference counter.

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Acked-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211018015418.10182-1-wanjiabing@vivo.com

powerpc/kexec_file: Use current CPU info while setting up FDT

kexec_file_load() uses initial_boot_params in setting up the device tree
for the kernel to be loaded. Though initial_boot_params holds info about
CPUs at the time of boot, it doesn't account for hot added CPUs.

So, kexec'ing with kexec_file_load() syscall leaves the kexec'ed kernel
with inaccurate CPU info.

If kdump kernel is loaded with kexec_file_load() syscall and the system
crashes on a hot added CPU, the capture kernel hangs failing to identify
the boot CPU, with no output.

To avoid this from happening, extract current CPU info from of_root
device node and use it for setting up the fdt in kexec_file_load case.

Fixes: 6ecd0163d360 ("powerpc/kexec_file: Add appropriate regions for memory reserve map")
Cc: stable@vger.kernel.org # v5.9+
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Reviewed-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210429060256.199714-1-sourabhjain@linux.ibm.com

powerpc/kexec_file: Restore FDT size estimation for kdump kernel

kexec_fdt_totalsize_ppc64() includes the base FDT size in its size
calculation, but commit 3c985d31ad66 ("powerpc: Use common
of_kexec_alloc_and_setup_fdt()") changed the kexec code to use the
generic function of_kexec_alloc_and_setup_fdt() which already includes
the base FDT size. That change made the code overestimate the size a bit
by counting twice the space required for the kernel command line and
/chosen properties.

Therefore change kexec_fdt_totalsize_ppc64() to calculate just the extra
space needed by the kdump kernel, and change the function name so that it
better reflects what the function is now doing.

Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: Hari Bathini <hbathini@linux.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
[robh: reword commit msg as no longer a fix from merging to branches]
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210220005204.1417200-1-bauerman@linux.ibm.com

powerpc: Move arch independent ima kexec functions to drivers/of/kexec.c

The functions defined in "arch/powerpc/kexec/ima.c" handle setting up
and freeing the resources required to carry over the IMA measurement
list from the current kernel to the next kernel across kexec system call.
These functions do not have architecture specific code, but are
currently limited to powerpc.

Move remove_ima_buffer() and setup_ima_buffer() calls into
of_kexec_alloc_and_setup_fdt() defined in "drivers/of/kexec.c".

Move the remaining architecture independent functions from
"arch/powerpc/kexec/ima.c" to "drivers/of/kexec.c".
Delete "arch/powerpc/kexec/ima.c" and "arch/powerpc/include/asm/ima.h".
Remove references to the deleted files and functions in powerpc and
in ima.

Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210221174930.27324-11-nramas@linux.microsoft.com

powerpc: Use common of_kexec_alloc_and_setup_fdt()

The code for setting up the /chosen node in the device tree
and updating the memory reservation for the next kernel has been
moved to of_kexec_alloc_and_setup_fdt() defined in "drivers/of/kexec.c".

Use the common of_kexec_alloc_and_setup_fdt() to setup the device tree
and update the memory reservation for kexec for powerpc.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210221174930.27324-8-nramas@linux.microsoft.com

powerpc: Use ELF fields defined in 'struct kimage'

ELF related fields elf_headers, elf_headers_sz, and elfcorehdr_addr
have been moved from 'struct kimage_arch' to 'struct kimage' as
elf_headers, elf_headers_sz, and elf_load_addr respectively.

Use the ELF fields defined in 'struct kimage'.

Suggested-by: Rob Herring <robh@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210221174930.27324-4-nramas@linux.microsoft.com

powerpc/kexec_file: fix FDT size estimation for kdump kernel

On systems with large amount of memory, loading kdump kernel through
kexec_file_load syscall may fail with the below error:

"Failed to update fdt with linux,drconf-usable-memory property"

This happens because the size estimation for kdump kernel's FDT does
not account for the additional space needed to setup usable memory
properties. Fix it by accounting for the space needed to include
linux,usable-memory & linux,drconf-usable-memory properties while
estimating kdump kernel's FDT size.

Fixes: 6ecd0163d360 ("powerpc/kexec_file: Add appropriate regions for memory reserve map")
Cc: stable@vger.kernel.org # v5.9+
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/161243826811.119001.14083048209224609814.stgit@hbathini

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>

memblock: reduce number of parameters in for_each_mem_range()

Currently for_each_mem_range() and for_each_mem_range_rev() iterators are
the most generic way to traverse memblock regions. As such, they have 8
parameters and they are hardly convenient to users. Most users choose to
utilize one of their wrappers and the only user that actually needs most
of the parameters is memblock itself.

To avoid yet another naming for memblock iterators, rename the existing
for_each_mem_range[_rev]() to __for_each_mem_range[_rev]() and add a new
for_each_mem_range[_rev]() wrappers with only index, start and end
parameters.

The new wrapper nicely fits into init_unavailable_mem() and will be used
in upcoming changes to simplify memblock traversals.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> [MIPS]
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 Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: https://lkml.kernel.org/r/20200818151634.14343-11-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

powerpc/kexec_file: Enable early kernel OPAL calls

Kernels built with CONFIG_PPC_EARLY_DEBUG_OPAL enabled expects r8 & r9
to be filled with OPAL base & entry addresses respectively. Setting
these registers allows the kernel to perform OPAL calls before the
device tree is parsed.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159602303975.575379.5032301944162937479.stgit@hbathini

powerpc/kexec_file: Fix kexec load failure with lack of memory hole

The kexec purgatory has to run in real mode. Only the first memory
block maybe accessible in real mode. And, unlike the case with panic
kernel, no memory is set aside for regular kexec load. Another thing
to note is, the memory for crashkernel is reserved at an offset of
128MB. So, when crashkernel memory is reserved, the memory ranges to
load kexec segments shrink further as the generic code only looks for
memblock free memory ranges and in all likelihood only a tiny bit of
memory from 0 to 128MB would be available to load kexec segments.

With kdump being used by default in general, kexec file load is likely
to fail almost always. This can be fixed by changing the memory hole
lookup logic for regular kexec to use the same method as kdump. This
would mean that most kexec segments will overlap with crashkernel
memory region. That should still be ok as the pages, whose destination
address isn't available while loading, are placed in an intermediate
location till a flush to the actual destination address happens during
kexec boot sequence.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159602302326.575379.14038896654942043093.stgit@hbathini

powerpc/kexec_file: Add appropriate regions for memory reserve map

While initrd, elfcorehdr and backup regions are already added to the
reserve map, there are a few missing regions that need to be added to
the memory reserve map. Add them here. And now that all the changes to
load panic kernel are in place, claim likewise.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159602300473.575379.4218568032039284448.stgit@hbathini

powerpc/kexec_file: Prepare elfcore header for crashing kernel

Prepare elf headers for the crashing kernel's core file using
crash_prepare_elf64_headers() and pass on this info to kdump kernel by
updating its command line with elfcorehdr parameter. Also, add
elfcorehdr location to reserve map to avoid it from being stomped on
while booting.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
[mpe: Ensure cmdline is nul terminated]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159602298855.575379.15819225623219909517.stgit@hbathini

powerpc/kexec_file: Setup backup region for kdump kernel

Though kdump kernel boots from loaded address, the first 64KB of it is
copied down to real 0. So, setup a backup region and let purgatory
copy the first 64KB of crashed kernel into this backup region before
booting into kdump kernel. Update reserve map with backup region and
crashed kernel's memory to avoid kdump kernel from accidentially using
that memory.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159602294718.575379.16216507537038008623.stgit@hbathini

powerpc/kexec_file: Restrict memory usage of kdump kernel

Kdump kernel, used for capturing the kernel core image, is supposed
to use only specific memory regions to avoid corrupting the image to
be captured. The regions are crashkernel range - the memory reserved
explicitly for kdump kernel, memory used for the tce-table, the OPAL
region and RTAS region as applicable. Restrict kdump kernel memory
to use only these regions by setting up usable-memory DT property.
Also, tell the kdump kernel to run at the loaded address by setting
the magic word at 0x5c.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159602284284.575379.6962016255404325493.stgit@hbathini

powerpc/kexec_file: Avoid stomping memory used by special regions

crashkernel region could have an overlap with special memory regions
like OPAL, RTAS, TCE table & such. These regions are referred to as
excluded memory ranges. Setup these ranges during image probe in order
to avoid them while finding the buffer for different kdump segments.
Override arch_kexec_locate_mem_hole() to locate a memory hole taking
these ranges into account.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159602281047.575379.6636807148335160795.stgit@hbathini

powerpc/kexec_file: Mark PPC64 specific code

Some of the kexec_file_load code isn't PPC64 specific. Move PPC64
specific code from kexec/file_load.c to kexec/file_load_64.c. Also,
rename purgatory/trampoline.S to purgatory/trampoline_64.S in the same
spirit. No functional changes.

Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159602276920.575379.10390965946438306388.stgit@hbathini