powerpc/8xx: Fix pte_access_permitted() for PAGE_NONE

On 8xx, PAGE_NONE is handled by setting _PAGE_NA instead of clearing
_PAGE_USER.

But then pte_user() returns 1 also for PAGE_NONE.

As _PAGE_NA

powerpc/8xx: Fix pte_access_permitted() for PAGE_NONE

On 8xx, PAGE_NONE is handled by setting _PAGE_NA instead of clearing
_PAGE_USER.

But then pte_user() returns 1 also for PAGE_NONE.

As _PAGE_NA prevent reads, add a specific version of pte_read()
that returns 0 when _PAGE_NA is set instead of always returning 1.

Fixes: 351750331fc1 ("powerpc/mm: Introduce _PAGE_NA")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/57bcfbe578e43123f9ed73e040229b80f1ad56ec.1695659959.git.christophe.leroy@csgroup.eu

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mm: Rename arch pte_mkwrite()'s to pte_mkwrite_novma()

The x86 Shadow stack feature includes a new type of memory called shadow
stack. This shadow stack memory has some unusual properties, which req

mm: Rename arch pte_mkwrite()'s to pte_mkwrite_novma()

The x86 Shadow stack feature includes a new type of memory called shadow
stack. This shadow stack memory has some unusual properties, which requires
some core mm changes to function properly.

One of these unusual properties is that shadow stack memory is writable,
but only in limited ways. These limits are applied via a specific PTE
bit combination. Nevertheless, the memory is writable, and core mm code
will need to apply the writable permissions in the typical paths that
call pte_mkwrite(). The goal is to make pte_mkwrite() take a VMA, so
that the x86 implementation of it can know whether to create regular
writable or shadow stack mappings.

But there are a couple of challenges to this. Modifying the signatures of
each arch pte_mkwrite() implementation would be error prone because some
are generated with macros and would need to be re-implemented. Also, some
pte_mkwrite() callers operate on kernel memory without a VMA.

So this can be done in a three step process. First pte_mkwrite() can be
renamed to pte_mkwrite_novma() in each arch, with a generic pte_mkwrite()
added that just calls pte_mkwrite_novma(). Next callers without a VMA can
be moved to pte_mkwrite_novma(). And lastly, pte_mkwrite() and all callers
can be changed to take/pass a VMA.

Start the process by renaming pte_mkwrite() to pte_mkwrite_novma() and
adding the pte_mkwrite() wrapper in linux/pgtable.h. Apply the same
pattern for pmd_mkwrite(). Since not all archs have a pmd_mkwrite_novma(),
create a new arch config HAS_HUGE_PAGE that can be used to tell if
pmd_mkwrite() should be defined. Otherwise in the !HAS_HUGE_PAGE cases the
compiler would not be able to find pmd_mkwrite_novma().

No functional change.

Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/lkml/CAHk-=wiZjSu7c9sFYZb3q04108stgHff2wfbokGCCgW7riz+8Q@mail.gmail.com/
Link: https://lore.kernel.org/all/20230613001108.3040476-2-rick.p.edgecombe%40intel.com

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powerpc/nohash: Fix __ptep_set_access_flags() and ptep_set_wrprotect()

Commit 26973fa5ac0e ("powerpc/mm: use pte helpers in generic code")
changed those two functions to use pte helpers to determine

powerpc/nohash: Fix __ptep_set_access_flags() and ptep_set_wrprotect()

Commit 26973fa5ac0e ("powerpc/mm: use pte helpers in generic code")
changed those two functions to use pte helpers to determine which
bits to clear and which bits to set.

This change was based on the assumption that bits to be set/cleared
are always the same and can be determined by applying the pte
manipulation helpers on __pte(0).

But on platforms like book3e, the bits depend on whether the page
is a user page or not.

For the time being it more or less works because of _PAGE_EXEC being
used for user pages only and exec right being set at all time on
kernel page. But following patch will clean that and output of
pte_mkexec() will depend on the page being a user or kernel page.

Instead of trying to make an even more complicated helper where bits
would become dependent on the final pte value, come back to a more
static situation like before commit 26973fa5ac0e ("powerpc/mm: use
pte helpers in generic code"), by introducing an 8xx specific
version of __ptep_set_access_flags() and ptep_set_wrprotect().

Fixes: 26973fa5ac0e ("powerpc/mm: use pte helpers in generic code")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/922bdab3a220781bae2360ff3dd5adb7fe4d34f1.1635226743.git.christophe.leroy@csgroup.eu

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powerpc/nohash: Fix __ptep_set_access_flags() and ptep_set_wrprotect()

[ Upstream commit b1b93cb7e794e914787bf7d9936b57a149cdee4f ]

Commit 26973fa5ac0e ("powerpc/mm: use pte helpers in generic code

powerpc/nohash: Fix __ptep_set_access_flags() and ptep_set_wrprotect()

[ Upstream commit b1b93cb7e794e914787bf7d9936b57a149cdee4f ]

Commit 26973fa5ac0e ("powerpc/mm: use pte helpers in generic code")
changed those two functions to use pte helpers to determine which
bits to clear and which bits to set.

This change was based on the assumption that bits to be set/cleared
are always the same and can be determined by applying the pte
manipulation helpers on __pte(0).

But on platforms like book3e, the bits depend on whether the page
is a user page or not.

For the time being it more or less works because of _PAGE_EXEC being
used for user pages only and exec right being set at all time on
kernel page. But following patch will clean that and output of
pte_mkexec() will depend on the page being a user or kernel page.

Instead of trying to make an even more complicated helper where bits
would become dependent on the final pte value, come back to a more
static situation like before commit 26973fa5ac0e ("powerpc/mm: use
pte helpers in generic code"), by introducing an 8xx specific
version of __ptep_set_access_flags() and ptep_set_wrprotect().

Fixes: 26973fa5ac0e ("powerpc/mm: use pte helpers in generic code")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/922bdab3a220781bae2360ff3dd5adb7fe4d34f1.1635226743.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>

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powerpc/8xx: Implement pXX_leaf_size() support

Christophe Leroy wrote:

> I can help with powerpc 8xx. It is a 32 bits powerpc. The PGD has 1024
> entries, that means each entry maps 4M.
>
> Page si

powerpc/8xx: Implement pXX_leaf_size() support

Christophe Leroy wrote:

> I can help with powerpc 8xx. It is a 32 bits powerpc. The PGD has 1024
> entries, that means each entry maps 4M.
>
> Page sizes are 4k, 16k, 512k and 8M.
>
> For the 8M pages we use hugepd with a single entry. The two related PGD
> entries point to the same hugepd.
>
> For the other sizes, they are in standard page tables. 16k pages appear
> 4 times in the page table. 512k entries appear 128 times in the page
> table.
>
> When the PGD entry has _PMD_PAGE_8M bits, the PMD entry points to a
> hugepd with holds the single 8M entry.
>
> In the PTE, we have two bits: _PAGE_SPS and _PAGE_HUGE
>
> _PAGE_HUGE means it is a 512k page
> _PAGE_SPS means it is not a 4k page
>
> The kernel can by build either with 4k pages as standard page size, or
> 16k pages. It doesn't change the page table layout though.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201126121121.364451610@infradead.org

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powerpc/8xx: Manage _PAGE_ACCESSED through APG bits in L1 entry

When _PAGE_ACCESSED is not set, a minor fault is expected.
To do this, TLB miss exception ANDs _PAGE_PRESENT and _PAGE_ACCESSED
into t

powerpc/8xx: Manage _PAGE_ACCESSED through APG bits in L1 entry

When _PAGE_ACCESSED is not set, a minor fault is expected.
To do this, TLB miss exception ANDs _PAGE_PRESENT and _PAGE_ACCESSED
into the L2 entry valid bit.

To simplify the processing and reduce the number of instructions in
TLB miss exceptions, manage it as an APG bit and get it next to
_PAGE_GUARDED bit to allow a copy in one go. Then declare the
corresponding groups as handling all accesses as user accesses.
As the PP bits always define user as No Access, it will generate
a fault.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/80f488db230c6b0e7b3b990d72bd94a8a069e93e.1602492856.git.christophe.leroy@csgroup.eu

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powerpc/8xx: Manage 512k huge pages as standard pages.

At the time being, 512k huge pages are handled through hugepd page
tables. The PMD entry is flagged as a hugepd pointer and it
means that only

powerpc/8xx: Manage 512k huge pages as standard pages.

At the time being, 512k huge pages are handled through hugepd page
tables. The PMD entry is flagged as a hugepd pointer and it
means that only 512k hugepages can be managed in that 4M block.
However, the hugepd table has the same size as a normal page
table, and 512k entries can therefore be nested with normal pages.

On the 8xx, TLB loading is performed by software and allthough the
page tables are organised to match the L1 and L2 level defined by
the HW, all TLB entries have both L1 and L2 independent entries.
It means that even if two TLB entries are associated with the same
PMD entry, they can be loaded with different values in L1 part.

The L1 entry contains the page size (PS field):
- 00 for 4k and 16 pages
- 01 for 512k pages
- 11 for 8M pages

By adding a flag for hugepages in the PTE (_PAGE_HUGE) and copying it
into the lower bit of PS, we can then manage 512k pages with normal
page tables:
- PMD entry has PS=11 for 8M pages
- PMD entry has PS=00 for other pages.

As a PMD entry covers 4M areas, a PMD will either point to a hugepd
table having a single entry to an 8M page, or the PMD will point to
a standard page table which will have either entries to 4k or 16k or
512k pages. For 512k pages, as the L1 entry will not know it is a
512k page before the PTE is read, there will be 128 entries in the
PTE as if it was 4k pages. But when loading the TLB, it will be
flagged as a 512k page.

Note that we can't use pmd_ptr() in asm/nohash/32/pgtable.h because
it is not defined yet.

In ITLB miss, we keep the possibility to opt it out as when kernel
text is pinned and no user hugepages are used, we can save several
instruction by not using r11.

In DTLB miss, that's just one instruction so it's not worth bothering
with 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/002819e8e166bf81d24b24782d98de7c40905d8f.1589866984.git.christophe.leroy@csgroup.eu

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powerpc/8xx: Remove PTE_ATOMIC_UPDATES

commit 1bc54c03117b9 ("powerpc: rework 4xx PTE access and TLB miss")
introduced non atomic PTE updates and started the work of removing
PTE updates in TLB miss

powerpc/8xx: Remove PTE_ATOMIC_UPDATES

commit 1bc54c03117b9 ("powerpc: rework 4xx PTE access and TLB miss")
introduced non atomic PTE updates and started the work of removing
PTE updates in TLB miss handlers, but kept PTE_ATOMIC_UPDATES for the
8xx with the following comment:
/* Until my rework is finished, 8xx still needs atomic PTE updates */

commit fe11dc3f9628e ("powerpc/8xx: Update TLB asm so it behaves as
linux mm expects") removed all PTE updates done in TLB miss handlers

Therefore, atomic PTE updates are not needed anymore for the 8xx

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

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powerpc/mm: Make pte_pgprot return all pte bits

Other archs do the same and instead of adding required pte bits (which
got masked out) in __ioremap_at(), make sure we filter only pfn bits
out.

Fixe

powerpc/mm: Make pte_pgprot return all pte bits

Other archs do the same and instead of adding required pte bits (which
got masked out) in __ioremap_at(), make sure we filter only pfn bits
out.

Fixes: 26973fa5ac0e ("powerpc/mm: use pte helpers in generic code")
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/8xx: change name of a few page flags to avoid confusion

_PAGE_PRIVILEGED corresponds to the SH bit which doesn't protect
against user access but only disables ASID verification on kernel
acc

powerpc/8xx: change name of a few page flags to avoid confusion

_PAGE_PRIVILEGED corresponds to the SH bit which doesn't protect
against user access but only disables ASID verification on kernel
accesses. User access is controlled with _PMD_USER flag.

Name it _PAGE_SH instead of _PAGE_PRIVILEGED

_PAGE_HUGE corresponds to the SPS bit which doesn't really tells
that's it is a huge page but only that it is not a 4k page.

Name it _PAGE_SPS instead of _PAGE_HUGE

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/mm: Define platform default caches related flags

Cache related flags like _PAGE_COHERENT and _PAGE_WRITETHRU
are defined on most platforms. The platforms not defining
them don't define any a

powerpc/mm: Define platform default caches related flags

Cache related flags like _PAGE_COHERENT and _PAGE_WRITETHRU
are defined on most platforms. The platforms not defining
them don't define any alternative. So we can give them a NUL
value directly for those platforms directly.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/mm: Allow platforms to redefine some helpers

The 40xx defines _PAGE_HWWRITE while others don't.
The 8xx defines _PAGE_RO instead of _PAGE_RW.
The 8xx defines _PAGE_PRIVILEGED instead of _PAG

powerpc/mm: Allow platforms to redefine some helpers

The 40xx defines _PAGE_HWWRITE while others don't.
The 8xx defines _PAGE_RO instead of _PAGE_RW.
The 8xx defines _PAGE_PRIVILEGED instead of _PAGE_USER.
The 8xx defines _PAGE_HUGE and _PAGE_NA while others don't.

Lets those platforms redefine pte_write(), pte_wrprotect() and
pte_mkwrite() and get _PAGE_RO and _PAGE_HWWRITE off the common
helpers.

Lets the 8xx redefine pte_user(), pte_mkprivileged() and pte_mkuser()
and get rid of _PAGE_PRIVILEGED and _PAGE_USER default values.

Lets the 8xx redefine pte_mkhuge() and get rid of
_PAGE_HUGE default value.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/mm: Distribute platform specific PAGE and PMD flags and definitions

The base kernel PAGE_XXXX definition sets are more or less platform
specific. Lets distribute them close to platform _PAGE

powerpc/mm: Distribute platform specific PAGE and PMD flags and definitions

The base kernel PAGE_XXXX definition sets are more or less platform
specific. Lets distribute them close to platform _PAGE_XXX flags
definition, and customise them to their exact platform flags.

Also defines _PAGE_PSIZE and _PTE_NONE_MASK for each platform
allthough they are defined as 0.

Do the same with _PMD flags like _PMD_USER and _PMD_PRESENT_MASK

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/8xx: Remove _PAGE_USER and handle user access at PMD level

As Linux kernel separates KERNEL and USER address spaces, there is
therefore no need to flag USER access at page level.

Today, the

powerpc/8xx: Remove _PAGE_USER and handle user access at PMD level

As Linux kernel separates KERNEL and USER address spaces, there is
therefore no need to flag USER access at page level.

Today, the 8xx TLB handlers already handle user access in the L1 entry
through Access Protection Groups, it is then natural to move the user
access handling at PMD level once _PAGE_NA allows to handle PAGE_NONE
protection without _PAGE_USER

In the mean time, as we free up one bit in the PTE, we can use it to
include SPS (page size flag) in the PTE and avoid handling it at every
TLB miss hence removing special handling based on compiled page size.

For _PAGE_EXEC, we rework it to use PP PTE bits, avoiding the copy
of _PAGE_EXEC bit into the L1 entry. Unfortunatly we are not
able to put it at the correct location as it conflicts with
NA/RO/RW bits for data entries.

Upper bits of APG in L1 entry overlap with PMD base address. In
order to avoid having to filter that out, we set up all groups so that
upper bits can have any value.

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

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powerpc/mm: extend _PAGE_PRIVILEGED to all CPUs

commit ac29c64089b74 ("powerpc/mm: Replace _PAGE_USER with
_PAGE_PRIVILEGED") introduced _PAGE_PRIVILEGED for BOOK3S/64

This patch generalises _PAGE_

powerpc/mm: extend _PAGE_PRIVILEGED to all CPUs

commit ac29c64089b74 ("powerpc/mm: Replace _PAGE_USER with
_PAGE_PRIVILEGED") introduced _PAGE_PRIVILEGED for BOOK3S/64

This patch generalises _PAGE_PRIVILEGED for all CPUs, allowing
to have either _PAGE_PRIVILEGED or _PAGE_USER or both.

PPC_8xx has a _PAGE_SHARED flag which is set for and only for
all non user pages. Lets rename it _PAGE_PRIVILEGED to remove
confusion as it has nothing to do with Linux shared pages.

On BookE, there's a _PAGE_BAP_SR which has to be set for kernel
pages: defining _PAGE_PRIVILEGED as _PAGE_BAP_SR will make
this generic

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

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powerpc/8xx: remove unused _PAGE_WRITETHRU

_PAGE_WRITETHRU is only used in:
* AMIGA_Z2RAM block driver which is never activated on powerPC
* Video/FB driver which is for PPC_PMAC

Therefore, no need

powerpc/8xx: remove unused _PAGE_WRITETHRU

_PAGE_WRITETHRU is only used in:
* AMIGA_Z2RAM block driver which is never activated on powerPC
* Video/FB driver which is for PPC_PMAC

Therefore, no need to spend time in 8xx TLB miss handlers for
handling it.

And by removing it, we free up bit 20 which then avoids having
to clear it on each TLB miss.

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

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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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powerpc/8xx: Implement support of hugepages

8xx uses a two level page table with two different linux page size
support (4k and 16k). 8xx also support two different hugepage sizes
512k and 8M. In ord

powerpc/8xx: Implement support of hugepages

8xx uses a two level page table with two different linux page size
support (4k and 16k). 8xx also support two different hugepage sizes
512k and 8M. In order to support them on linux we define two different
page table layout.

The size of pages is in the PGD entry, using PS field (bits 28-29):
00 : Small pages (4k or 16k)
01 : 512k pages
10 : reserved
11 : 8M pages

For 512K hugepage size a pgd entry have the below format
[<hugepte address >0101] . The hugepte table allocated will contain 8
entries pointing to 512K huge pte in 4k pages mode and 64 entries in
16k pages mode.

For 8M in 16k mode, a pgd entry have the below format
[<hugepte address >1101] . The hugepte table allocated will contain 8
entries pointing to 8M huge pte.

For 8M in 4k mode, multiple pgd entries point to the same hugepte
address and pgd entry will have the below format
[<hugepte address>1101]. The hugepte table allocated will only have one
entry.

For the time being, we do not support CPU15 ERRATA when HUGETLB is
selected

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> (v3, for the generic bits)
Signed-off-by: Scott Wood <oss@buserror.net>

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powerpc/booke: Move nohash headers

Move the booke related headers below booke/32 or booke/64

Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.

powerpc/booke: Move nohash headers

Move the booke related headers below booke/32 or booke/64

Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/8xx: Manage _PAGE_ACCESSED through APG bits in L1 entry

When _PAGE_ACCESSED is not set, a minor fault is expected.
To do this, TLB miss exception ANDs _PAGE_PRESENT and _PAGE_ACC

powerpc/8xx: Manage _PAGE_ACCESSED through APG bits in L1 entry

When _PAGE_ACCESSED is not set, a minor fault is expected.
To do this, TLB miss exception ANDs _PAGE_PRESENT and _PAGE_ACCESSED
into the L2 entry valid bit.

To simplify the processing and reduce the number of instructions in
TLB miss exceptions, manage it as an APG bit and get it next to
_PAGE_GUARDED bit to allow a copy in one go. Then declare the
corresponding groups as handling all accesses as user accesses.
As the PP bits always define user as No Access, it will generate
a fault.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/80f488db230c6b0e7b3b990d72bd94a8a069e93e.1602492856.git.christophe.leroy@csgroup.eu

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powerpc/8xx: Manage 512k huge pages as standard pages.

At the time being, 512k huge pages are handled through hugepd page
tables. The PMD entry is flagged as a hugepd pointer and it

powerpc/8xx: Manage 512k huge pages as standard pages.

At the time being, 512k huge pages are handled through hugepd page
tables. The PMD entry is flagged as a hugepd pointer and it
means that only 512k hugepages can be managed in that 4M block.
However, the hugepd table has the same size as a normal page
table, and 512k entries can therefore be nested with normal pages.

On the 8xx, TLB loading is performed by software and allthough the
page tables are organised to match the L1 and L2 level defined by
the HW, all TLB entries have both L1 and L2 independent entries.
It means that even if two TLB entries are associated with the same
PMD entry, they can be loaded with different values in L1 part.

The L1 entry contains the page size (PS field):
- 00 for 4k and 16 pages
- 01 for 512k pages
- 11 for 8M pages

By adding a flag for hugepages in the PTE (_PAGE_HUGE) and copying it
into the lower bit of PS, we can then manage 512k pages with normal
page tables:
- PMD entry has PS=11 for 8M pages
- PMD entry has PS=00 for other pages.

As a PMD entry covers 4M areas, a PMD will either point to a hugepd
table having a single entry to an 8M page, or the PMD will point to
a standard page table which will have either entries to 4k or 16k or
512k pages. For 512k pages, as the L1 entry will not know it is a
512k page before the PTE is read, there will be 128 entries in the
PTE as if it was 4k pages. But when loading the TLB, it will be
flagged as a 512k page.

Note that we can't use pmd_ptr() in asm/nohash/32/pgtable.h because
it is not defined yet.

In ITLB miss, we keep the possibility to opt it out as when kernel
text is pinned and no user hugepages are used, we can save several
instruction by not using r11.

In DTLB miss, that's just one instruction so it's not worth bothering
with 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/002819e8e166bf81d24b24782d98de7c40905d8f.1589866984.git.christophe.leroy@csgroup.eu

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powerpc/8xx: Remove PTE_ATOMIC_UPDATES

commit 1bc54c03117b9 ("powerpc: rework 4xx PTE access and TLB miss")
introduced non atomic PTE updates and started the work of removing
PTE upd

powerpc/8xx: Remove PTE_ATOMIC_UPDATES

commit 1bc54c03117b9 ("powerpc: rework 4xx PTE access and TLB miss")
introduced non atomic PTE updates and started the work of removing
PTE updates in TLB miss handlers, but kept PTE_ATOMIC_UPDATES for the
8xx with the following comment:
/* Until my rework is finished, 8xx still needs atomic PTE updates */

commit fe11dc3f9628e ("powerpc/8xx: Update TLB asm so it behaves as
linux mm expects") removed all PTE updates done in TLB miss handlers

Therefore, atomic PTE updates are not needed anymore for the 8xx

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

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powerpc/mm: Make pte_pgprot return all pte bits

Other archs do the same and instead of adding required pte bits (which
got masked out) in __ioremap_at(), make sure we filter only pfn bit

powerpc/mm: Make pte_pgprot return all pte bits

Other archs do the same and instead of adding required pte bits (which
got masked out) in __ioremap_at(), make sure we filter only pfn bits
out.

Fixes: 26973fa5ac0e ("powerpc/mm: use pte helpers in generic code")
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/8xx: change name of a few page flags to avoid confusion

_PAGE_PRIVILEGED corresponds to the SH bit which doesn't protect
against user access but only disables ASID verification o

powerpc/8xx: change name of a few page flags to avoid confusion

_PAGE_PRIVILEGED corresponds to the SH bit which doesn't protect
against user access but only disables ASID verification on kernel
accesses. User access is controlled with _PMD_USER flag.

Name it _PAGE_SH instead of _PAGE_PRIVILEGED

_PAGE_HUGE corresponds to the SPS bit which doesn't really tells
that's it is a huge page but only that it is not a 4k page.

Name it _PAGE_SPS instead of _PAGE_HUGE

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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powerpc/mm: Define platform default caches related flags

Cache related flags like _PAGE_COHERENT and _PAGE_WRITETHRU
are defined on most platforms. The platforms not defining
them do

powerpc/mm: Define platform default caches related flags

Cache related flags like _PAGE_COHERENT and _PAGE_WRITETHRU
are defined on most platforms. The platforms not defining
them don't define any alternative. So we can give them a NUL
value directly for those platforms directly.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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