ARM: mm: Make virt_to_pfn() a static inline

Making virt_to_pfn() a static inline taking a strongly typed
(const void *) makes the contract of a passing a pointer of that
type to the function explici

ARM: mm: Make virt_to_pfn() a static inline

Making virt_to_pfn() a static inline taking a strongly typed
(const void *) makes the contract of a passing a pointer of that
type to the function explicit and exposes any misuse of the
macro virt_to_pfn() acting polymorphic and accepting many types
such as (void *), (unitptr_t) or (unsigned long) as arguments
without warnings.

Doing this is a bit intrusive: virt_to_pfn() requires
PHYS_PFN_OFFSET and PAGE_SHIFT to be defined, and this is defined in
<asm/page.h>, so this must be included *before* <asm/memory.h>.

The use of macros were obscuring the unclear inclusion order here,
as the macros would eventually be resolved, but a static inline
like this cannot be compiled with unresolved macros.

The naive solution to include <asm/page.h> at the top of
<asm/memory.h> does not work, because <asm/memory.h> sometimes
includes <asm/page.h> at the end of itself, which would create a
confusing inclusion loop. So instead, take the approach to always
unconditionally include <asm/page.h> at the end of <asm/memory.h>

arch/arm uses <asm/memory.h> explicitly in a lot of places,
however it turns out that if we just unconditionally include
<asm/memory.h> into <asm/page.h> and switch all inclusions of
<asm/memory.h> to <asm/page.h> instead, we enforce the right
order and <asm/memory.h> will always have access to the
definitions.

Put an inclusion guard in place making it impossible to include
<asm/memory.h> explicitly.

Link: https://lore.kernel.org/linux-mm/20220701160004.2ffff4e5ab59a55499f4c736@linux-foundation.org/
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

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ARM: 9140/1: allow compile-testing without machine record

A lot of randconfig builds end up not selecting any machine type at
all. This is generally fine for the purpose of compile testing, but
of c

ARM: 9140/1: allow compile-testing without machine record

A lot of randconfig builds end up not selecting any machine type at
all. This is generally fine for the purpose of compile testing, but
of course it means that the kernel is not usable on actual hardware,
and it causes a warning about this fact.

As most of the build bots now force-enable CONFIG_COMPILE_TEST for
randconfig builds, use that as a guard to control whether we warn
on this type of broken configuration.

We could do the same for the missing-cpu-type warning, but those
configurations fail to build much earlier.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

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ARM: 9141/1: only warn about XIP address when not compile testing

In randconfig builds, we sometimes come across this warning:

arm-linux-gnueabi-ld: XIP start address may cause MPU programming issu

ARM: 9141/1: only warn about XIP address when not compile testing

In randconfig builds, we sometimes come across this warning:

arm-linux-gnueabi-ld: XIP start address may cause MPU programming issues

While this is helpful for actual systems to figure out why it
fails, the warning does not provide any benefit for build testing,
so guard it in a check for CONFIG_COMPILE_TEST, which is usually
set on randconfig builds.

Fixes: 216218308cfb ("ARM: 8713/1: NOMMU: Support MPU in XIP configuration")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

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ARM: 9138/1: fix link warning with XIP + frame-pointer

When frame pointers are used instead of the ARM unwinder,
and the kernel is built using clang with an external assembler
and CONFIG_XIP_KERNEL,

ARM: 9138/1: fix link warning with XIP + frame-pointer

When frame pointers are used instead of the ARM unwinder,
and the kernel is built using clang with an external assembler
and CONFIG_XIP_KERNEL, every file produces two warnings
like:

arm-linux-gnueabi-ld: warning: orphan section `.ARM.extab' from `net/mac802154/util.o' being placed in section `.ARM.extab'
arm-linux-gnueabi-ld: warning: orphan section `.ARM.exidx' from `net/mac802154/util.o' being placed in section `.ARM.exidx'

The same fix was already merged for the normal (non-XIP)

linker script, with a longer description.

Fixes: c39866f268f8 ("arm/build: Always handle .ARM.exidx and .ARM.extab sections")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

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arm/build: Assert for unwanted sections

In preparation for warning on orphan sections, enforce
expected-to-be-zero-sized sections (since discarding them might hide
problems with them suddenly gainin

arm/build: Assert for unwanted sections

In preparation for warning on orphan sections, enforce
expected-to-be-zero-sized sections (since discarding them might hide
problems with them suddenly gaining unexpected entries).

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Link: https://lore.kernel.org/r/20200821194310.3089815-19-keescook@chromium.org

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arm/build: Add missing sections

Add missing text stub sections .vfp11_veneer and .v4_bx, as well as
missing DWARF sections, when present in the build.

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

arm/build: Add missing sections

Add missing text stub sections .vfp11_veneer and .v4_bx, as well as
missing DWARF sections, when present in the build.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: Russell King <linux@armlinux.org.uk>
Link: https://lore.kernel.org/r/20200821194310.3089815-18-keescook@chromium.org

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arm/build: Explicitly keep .ARM.attributes sections

In preparation for adding --orphan-handling=warn, explicitly keep the
.ARM.attributes section (at address 0[1]) by expanding the existing
ELF_DETA

arm/build: Explicitly keep .ARM.attributes sections

In preparation for adding --orphan-handling=warn, explicitly keep the
.ARM.attributes section (at address 0[1]) by expanding the existing
ELF_DETAILS macro into ARM_DETAILS.

[1] https://reviews.llvm.org/D85867

Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Cc: Russell King <linux@armlinux.org.uk>
Link: https://lore.kernel.org/lkml/CAKwvOdk-racgq5pxsoGS6Vtifbtrk5fmkmnoLxrQMaOvV0nPWw@mail.gmail.com/
Link: https://lore.kernel.org/r/20200821194310.3089815-17-keescook@chromium.org

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arm/build: Refactor linker script headers

In preparation for adding --orphan-handling=warn, refactor the linker
script header includes, and extract common macros.

Signed-off-by: Kees Cook <keescook

arm/build: Refactor linker script headers

In preparation for adding --orphan-handling=warn, refactor the linker
script header includes, and extract common macros.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Link: https://lore.kernel.org/r/20200821194310.3089815-16-keescook@chromium.org

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vmlinux.lds.h: Split ELF_DETAILS from STABS_DEBUG

The .comment section doesn't belong in STABS_DEBUG. Split it out into a
new macro named ELF_DETAILS. This will gain other non-debug sections
that ne

vmlinux.lds.h: Split ELF_DETAILS from STABS_DEBUG

The .comment section doesn't belong in STABS_DEBUG. Split it out into a
new macro named ELF_DETAILS. This will gain other non-debug sections
that need to be accounted for when linking with --orphan-handling=warn.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-arch@vger.kernel.org
Link: https://lore.kernel.org/r/20200821194310.3089815-5-keescook@chromium.org

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arm: Remove HYP/Stage-2 page-table support

Remove all traces of Stage-2 and HYP page table support.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by:

arm: Remove HYP/Stage-2 page-table support

Remove all traces of Stage-2 and HYP page table support.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>

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vmlinux.lds.h: Replace RW_DATA_SECTION with RW_DATA

Rename RW_DATA_SECTION to RW_DATA. (Calling this a "section" is a lie,
since it's multiple sections and section flags cannot be applied to
the mac

vmlinux.lds.h: Replace RW_DATA_SECTION with RW_DATA

Rename RW_DATA_SECTION to RW_DATA. (Calling this a "section" is a lie,
since it's multiple sections and section flags cannot be applied to
the macro.)

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Will Deacon <will@kernel.org>
Cc: x86-ml <x86@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: https://lkml.kernel.org/r/20191029211351.13243-14-keescook@chromium.org

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vmlinux.lds.h: Move NOTES into RO_DATA

The .notes section should be non-executable read-only data. As such,
move it to the RO_DATA macro instead of being per-architecture defined.

Signed-off-by: Ke

vmlinux.lds.h: Move NOTES into RO_DATA

The .notes section should be non-executable read-only data. As such,
move it to the RO_DATA macro instead of being per-architecture defined.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Will Deacon <will@kernel.org>
Cc: x86-ml <x86@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: https://lkml.kernel.org/r/20191029211351.13243-11-keescook@chromium.org

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vmlinux.lds.h: Move LSM_TABLE into INIT_DATA

Since the struct lsm_info table is not an initcall, we can just move it
into INIT_DATA like all the other tables.

Signed-off-by: Kees Cook <keescook@chr

vmlinux.lds.h: Move LSM_TABLE into INIT_DATA

Since the struct lsm_info table is not an initcall, we can just move it
into INIT_DATA like all the other tables.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Reviewed-by: James Morris <james.morris@microsoft.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

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ARM: 8757/1: NOMMU: Support PMSAv8 MPU

ARMv8R/M architecture defines new memory protection scheme - PMSAv8
which is not compatible with PMSAv7.

Key differences to PMSAv7 are:
- Region geometry is

ARM: 8757/1: NOMMU: Support PMSAv8 MPU

ARMv8R/M architecture defines new memory protection scheme - PMSAv8
which is not compatible with PMSAv7.

Key differences to PMSAv7 are:
- Region geometry is defined by base and limit addresses
- Addresses need to be either 32 or 64 byte aligned
- No region priority due to overlapping regions are not allowed
- It is unified, i.e. no distinction between data/instruction regions
- Memory attributes are controlled via MAIR

This patch implements support for PMSAv8 MPU defined by ARMv8R/M
architecture.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

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ARM: simplify and fix linker script for TCM

Let's put the TCM stuff in the __init section directly. No need for
a separately freed memory area.

Remove redundant linker sections, as well as comments

ARM: simplify and fix linker script for TCM

Let's put the TCM stuff in the __init section directly. No need for
a separately freed memory area.

Remove redundant linker sections, as well as comments that were more
confusing than no comments at all. Finally make it XIP compatible by
using LOAD_OFFSET in the section LMA specification.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>

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ARM: linker script: factor out TCM bits

This is a plain move with identical results, and therefore
still broken in the XIP case.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Bran

ARM: linker script: factor out TCM bits

This is a plain move with identical results, and therefore
still broken in the XIP case.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>

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ARM: linker script: factor out vectors and stubs

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>

ARM: linker script: factor out unwinding table sections

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>

ARM: linker script: factor out stuff for the .text section

Move common entries to vmlinux.lds.h as ARM_TEXT.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@ren

ARM: linker script: factor out stuff for the .text section

Move common entries to vmlinux.lds.h as ARM_TEXT.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>

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ARM: linker script: factor out stuff for the DISCARD section

Move common entries to vmlinux.lds.h and leave XIP and non-XIP entries
in their respective file. The ARM_NOMMU_KEEP() and ARM_NOMMU_DISCA

ARM: linker script: factor out stuff for the DISCARD section

Move common entries to vmlinux.lds.h and leave XIP and non-XIP entries
in their respective file. The ARM_NOMMU_KEEP() and ARM_NOMMU_DISCARD()
macros are added to be usable within the definition of ARM_DISCARD macro.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>

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ARM: linker script: factor out some common definitions between XIP and non-XIP

Lots of duplications between vmlinux.lds.S and vmlinux-xip.lds.S.
This may lead to one file being updated but not the o

ARM: linker script: factor out some common definitions between XIP and non-XIP

Lots of duplications between vmlinux.lds.S and vmlinux-xip.lds.S.
This may lead to one file being updated but not the other. For example,
SOFTIRQENTRY_TEXT and HYPERVISOR_TEXT were missing from the XIP version.

This creates vmlinux.lds.h where a bunch of common defines are moved.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>

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ARM: probes: avoid adding kprobes to sensitive kernel-entry/exit code

Avoid adding kprobes to any of the kernel entry/exit or startup
assembly code, or code in the identity-mapped region. This code

ARM: probes: avoid adding kprobes to sensitive kernel-entry/exit code

Avoid adding kprobes to any of the kernel entry/exit or startup
assembly code, or code in the identity-mapped region. This code does
not conform to the standard C conventions, which means that the
expectations of the kprobes code is not forfilled.

Placing kprobes at some of these locations results in the kernel trying
to return to userspace addresses while retaining the CPU in kernel mode.

Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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ARM: 8713/1: NOMMU: Support MPU in XIP configuration

Currently, there is assumption in early MPU setup code that kernel
image is located in RAM, which is obviously not true for XIP. To run
code from

ARM: 8713/1: NOMMU: Support MPU in XIP configuration

Currently, there is assumption in early MPU setup code that kernel
image is located in RAM, which is obviously not true for XIP. To run
code from ROM we need to make sure that it is covered by MPU. However,
due to we allocate regions (semi-)dynamically we can run into issue of
trimming region we are running from in case ROM spawns several MPU
regions. To help deal with that we enforce minimum alignments for start
end end of XIP address space as 1MB and 128Kb correspondingly.

Tested-by: Alexandre TORGUE <alexandre.torgue@st.com>
Tested-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

show more ...

ARM: XIP kernel: store .data compressed in ROM

The .data segment stored in ROM is only copied to RAM once at boot time
and never referenced afterwards. This is arguably a suboptimal usage of
ROM res

ARM: XIP kernel: store .data compressed in ROM

The .data segment stored in ROM is only copied to RAM once at boot time
and never referenced afterwards. This is arguably a suboptimal usage of
ROM resources.

This patch allows for compressing the .data segment before storing it
into ROM and decompressing it to RAM rather than simply copying it,
saving on precious ROM space.

Because global data is not available yet (obviously) we must allocate
decompressor workspace memory on the stack. The .bss area is used as a
stack area for that purpose before it is cleared. The required stack
frame is 9568 bytes for __inflate_kernel_data() alone, so make sure
the .bss is large enough to cope with that plus extra room for called
functions or fail the build.

Those numbers were picked arbitrarily based on the above 9568 byte
stack frame:

10240 (2.5 * PAGE_SIZE): used to override -Wframe-larger-than whose
default value is 1024.
12288 (3 * PAGE_SIZE): minimum .bss size to contain the stack.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>

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