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>
2017-11-01 22:07:57 +08:00
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// SPDX-License-Identifier: GPL-2.0
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2005-04-17 06:20:36 +08:00
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/* arch/sparc64/mm/tlb.c
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*
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* Copyright (C) 2004 David S. Miller <davem@redhat.com>
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*/
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#include <linux/kernel.h>
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#include <linux/percpu.h>
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#include <linux/mm.h>
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#include <linux/swap.h>
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2006-05-01 13:54:27 +08:00
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#include <linux/preempt.h>
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2005-04-17 06:20:36 +08:00
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/tlbflush.h>
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#include <asm/cacheflush.h>
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#include <asm/mmu_context.h>
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#include <asm/tlb.h>
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/* Heavily inspired by the ppc64 code. */
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2011-05-25 08:11:50 +08:00
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static DEFINE_PER_CPU(struct tlb_batch, tlb_batch);
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2005-04-17 06:20:36 +08:00
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void flush_tlb_pending(void)
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{
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2011-05-25 08:11:50 +08:00
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struct tlb_batch *tb = &get_cpu_var(tlb_batch);
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sparc64: Fix race in TLB batch processing.
As reported by Dave Kleikamp, when we emit cross calls to do batched
TLB flush processing we have a race because we do not synchronize on
the sibling cpus completing the cross call.
So meanwhile the TLB batch can be reset (tb->tlb_nr set to zero, etc.)
and either flushes are missed or flushes will flush the wrong
addresses.
Fix this by using generic infrastructure to synchonize on the
completion of the cross call.
This first required getting the flush_tlb_pending() call out from
switch_to() which operates with locks held and interrupts disabled.
The problem is that smp_call_function_many() cannot be invoked with
IRQs disabled and this is explicitly checked for with WARN_ON_ONCE().
We get the batch processing outside of locked IRQ disabled sections by
using some ideas from the powerpc port. Namely, we only batch inside
of arch_{enter,leave}_lazy_mmu_mode() calls. If we're not in such a
region, we flush TLBs synchronously.
1) Get rid of xcall_flush_tlb_pending and per-cpu type
implementations.
2) Do TLB batch cross calls instead via:
smp_call_function_many()
tlb_pending_func()
__flush_tlb_pending()
3) Batch only in lazy mmu sequences:
a) Add 'active' member to struct tlb_batch
b) Define __HAVE_ARCH_ENTER_LAZY_MMU_MODE
c) Set 'active' in arch_enter_lazy_mmu_mode()
d) Run batch and clear 'active' in arch_leave_lazy_mmu_mode()
e) Check 'active' in tlb_batch_add_one() and do a synchronous
flush if it's clear.
4) Add infrastructure for synchronous TLB page flushes.
a) Implement __flush_tlb_page and per-cpu variants, patch
as needed.
b) Likewise for xcall_flush_tlb_page.
c) Implement smp_flush_tlb_page() to invoke the cross-call.
d) Wire up global_flush_tlb_page() to the right routine based
upon CONFIG_SMP
5) It turns out that singleton batches are very common, 2 out of every
3 batch flushes have only a single entry in them.
The batch flush waiting is very expensive, both because of the poll
on sibling cpu completeion, as well as because passing the tlb batch
pointer to the sibling cpus invokes a shared memory dereference.
Therefore, in flush_tlb_pending(), if there is only one entry in
the batch perform a completely asynchronous global_flush_tlb_page()
instead.
Reported-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
2013-04-20 05:26:26 +08:00
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struct mm_struct *mm = tb->mm;
|
2005-04-17 06:20:36 +08:00
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|
|
sparc64: Fix race in TLB batch processing.
As reported by Dave Kleikamp, when we emit cross calls to do batched
TLB flush processing we have a race because we do not synchronize on
the sibling cpus completing the cross call.
So meanwhile the TLB batch can be reset (tb->tlb_nr set to zero, etc.)
and either flushes are missed or flushes will flush the wrong
addresses.
Fix this by using generic infrastructure to synchonize on the
completion of the cross call.
This first required getting the flush_tlb_pending() call out from
switch_to() which operates with locks held and interrupts disabled.
The problem is that smp_call_function_many() cannot be invoked with
IRQs disabled and this is explicitly checked for with WARN_ON_ONCE().
We get the batch processing outside of locked IRQ disabled sections by
using some ideas from the powerpc port. Namely, we only batch inside
of arch_{enter,leave}_lazy_mmu_mode() calls. If we're not in such a
region, we flush TLBs synchronously.
1) Get rid of xcall_flush_tlb_pending and per-cpu type
implementations.
2) Do TLB batch cross calls instead via:
smp_call_function_many()
tlb_pending_func()
__flush_tlb_pending()
3) Batch only in lazy mmu sequences:
a) Add 'active' member to struct tlb_batch
b) Define __HAVE_ARCH_ENTER_LAZY_MMU_MODE
c) Set 'active' in arch_enter_lazy_mmu_mode()
d) Run batch and clear 'active' in arch_leave_lazy_mmu_mode()
e) Check 'active' in tlb_batch_add_one() and do a synchronous
flush if it's clear.
4) Add infrastructure for synchronous TLB page flushes.
a) Implement __flush_tlb_page and per-cpu variants, patch
as needed.
b) Likewise for xcall_flush_tlb_page.
c) Implement smp_flush_tlb_page() to invoke the cross-call.
d) Wire up global_flush_tlb_page() to the right routine based
upon CONFIG_SMP
5) It turns out that singleton batches are very common, 2 out of every
3 batch flushes have only a single entry in them.
The batch flush waiting is very expensive, both because of the poll
on sibling cpu completeion, as well as because passing the tlb batch
pointer to the sibling cpus invokes a shared memory dereference.
Therefore, in flush_tlb_pending(), if there is only one entry in
the batch perform a completely asynchronous global_flush_tlb_page()
instead.
Reported-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
2013-04-20 05:26:26 +08:00
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if (!tb->tlb_nr)
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goto out;
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2006-02-01 10:29:18 +08:00
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sparc64: Fix race in TLB batch processing.
As reported by Dave Kleikamp, when we emit cross calls to do batched
TLB flush processing we have a race because we do not synchronize on
the sibling cpus completing the cross call.
So meanwhile the TLB batch can be reset (tb->tlb_nr set to zero, etc.)
and either flushes are missed or flushes will flush the wrong
addresses.
Fix this by using generic infrastructure to synchonize on the
completion of the cross call.
This first required getting the flush_tlb_pending() call out from
switch_to() which operates with locks held and interrupts disabled.
The problem is that smp_call_function_many() cannot be invoked with
IRQs disabled and this is explicitly checked for with WARN_ON_ONCE().
We get the batch processing outside of locked IRQ disabled sections by
using some ideas from the powerpc port. Namely, we only batch inside
of arch_{enter,leave}_lazy_mmu_mode() calls. If we're not in such a
region, we flush TLBs synchronously.
1) Get rid of xcall_flush_tlb_pending and per-cpu type
implementations.
2) Do TLB batch cross calls instead via:
smp_call_function_many()
tlb_pending_func()
__flush_tlb_pending()
3) Batch only in lazy mmu sequences:
a) Add 'active' member to struct tlb_batch
b) Define __HAVE_ARCH_ENTER_LAZY_MMU_MODE
c) Set 'active' in arch_enter_lazy_mmu_mode()
d) Run batch and clear 'active' in arch_leave_lazy_mmu_mode()
e) Check 'active' in tlb_batch_add_one() and do a synchronous
flush if it's clear.
4) Add infrastructure for synchronous TLB page flushes.
a) Implement __flush_tlb_page and per-cpu variants, patch
as needed.
b) Likewise for xcall_flush_tlb_page.
c) Implement smp_flush_tlb_page() to invoke the cross-call.
d) Wire up global_flush_tlb_page() to the right routine based
upon CONFIG_SMP
5) It turns out that singleton batches are very common, 2 out of every
3 batch flushes have only a single entry in them.
The batch flush waiting is very expensive, both because of the poll
on sibling cpu completeion, as well as because passing the tlb batch
pointer to the sibling cpus invokes a shared memory dereference.
Therefore, in flush_tlb_pending(), if there is only one entry in
the batch perform a completely asynchronous global_flush_tlb_page()
instead.
Reported-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
2013-04-20 05:26:26 +08:00
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flush_tsb_user(tb);
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if (CTX_VALID(mm->context)) {
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if (tb->tlb_nr == 1) {
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global_flush_tlb_page(mm, tb->vaddrs[0]);
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} else {
|
2005-04-17 06:20:36 +08:00
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#ifdef CONFIG_SMP
|
2011-05-25 08:11:50 +08:00
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smp_flush_tlb_pending(tb->mm, tb->tlb_nr,
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&tb->vaddrs[0]);
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2005-04-17 06:20:36 +08:00
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#else
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2011-05-25 08:11:50 +08:00
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__flush_tlb_pending(CTX_HWBITS(tb->mm->context),
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tb->tlb_nr, &tb->vaddrs[0]);
|
2005-04-17 06:20:36 +08:00
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#endif
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}
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}
|
2006-05-01 13:54:27 +08:00
|
|
|
|
sparc64: Fix race in TLB batch processing.
As reported by Dave Kleikamp, when we emit cross calls to do batched
TLB flush processing we have a race because we do not synchronize on
the sibling cpus completing the cross call.
So meanwhile the TLB batch can be reset (tb->tlb_nr set to zero, etc.)
and either flushes are missed or flushes will flush the wrong
addresses.
Fix this by using generic infrastructure to synchonize on the
completion of the cross call.
This first required getting the flush_tlb_pending() call out from
switch_to() which operates with locks held and interrupts disabled.
The problem is that smp_call_function_many() cannot be invoked with
IRQs disabled and this is explicitly checked for with WARN_ON_ONCE().
We get the batch processing outside of locked IRQ disabled sections by
using some ideas from the powerpc port. Namely, we only batch inside
of arch_{enter,leave}_lazy_mmu_mode() calls. If we're not in such a
region, we flush TLBs synchronously.
1) Get rid of xcall_flush_tlb_pending and per-cpu type
implementations.
2) Do TLB batch cross calls instead via:
smp_call_function_many()
tlb_pending_func()
__flush_tlb_pending()
3) Batch only in lazy mmu sequences:
a) Add 'active' member to struct tlb_batch
b) Define __HAVE_ARCH_ENTER_LAZY_MMU_MODE
c) Set 'active' in arch_enter_lazy_mmu_mode()
d) Run batch and clear 'active' in arch_leave_lazy_mmu_mode()
e) Check 'active' in tlb_batch_add_one() and do a synchronous
flush if it's clear.
4) Add infrastructure for synchronous TLB page flushes.
a) Implement __flush_tlb_page and per-cpu variants, patch
as needed.
b) Likewise for xcall_flush_tlb_page.
c) Implement smp_flush_tlb_page() to invoke the cross-call.
d) Wire up global_flush_tlb_page() to the right routine based
upon CONFIG_SMP
5) It turns out that singleton batches are very common, 2 out of every
3 batch flushes have only a single entry in them.
The batch flush waiting is very expensive, both because of the poll
on sibling cpu completeion, as well as because passing the tlb batch
pointer to the sibling cpus invokes a shared memory dereference.
Therefore, in flush_tlb_pending(), if there is only one entry in
the batch perform a completely asynchronous global_flush_tlb_page()
instead.
Reported-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
2013-04-20 05:26:26 +08:00
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tb->tlb_nr = 0;
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out:
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2011-05-25 08:11:50 +08:00
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put_cpu_var(tlb_batch);
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2005-04-17 06:20:36 +08:00
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}
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|
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|
|
sparc64: Fix race in TLB batch processing.
As reported by Dave Kleikamp, when we emit cross calls to do batched
TLB flush processing we have a race because we do not synchronize on
the sibling cpus completing the cross call.
So meanwhile the TLB batch can be reset (tb->tlb_nr set to zero, etc.)
and either flushes are missed or flushes will flush the wrong
addresses.
Fix this by using generic infrastructure to synchonize on the
completion of the cross call.
This first required getting the flush_tlb_pending() call out from
switch_to() which operates with locks held and interrupts disabled.
The problem is that smp_call_function_many() cannot be invoked with
IRQs disabled and this is explicitly checked for with WARN_ON_ONCE().
We get the batch processing outside of locked IRQ disabled sections by
using some ideas from the powerpc port. Namely, we only batch inside
of arch_{enter,leave}_lazy_mmu_mode() calls. If we're not in such a
region, we flush TLBs synchronously.
1) Get rid of xcall_flush_tlb_pending and per-cpu type
implementations.
2) Do TLB batch cross calls instead via:
smp_call_function_many()
tlb_pending_func()
__flush_tlb_pending()
3) Batch only in lazy mmu sequences:
a) Add 'active' member to struct tlb_batch
b) Define __HAVE_ARCH_ENTER_LAZY_MMU_MODE
c) Set 'active' in arch_enter_lazy_mmu_mode()
d) Run batch and clear 'active' in arch_leave_lazy_mmu_mode()
e) Check 'active' in tlb_batch_add_one() and do a synchronous
flush if it's clear.
4) Add infrastructure for synchronous TLB page flushes.
a) Implement __flush_tlb_page and per-cpu variants, patch
as needed.
b) Likewise for xcall_flush_tlb_page.
c) Implement smp_flush_tlb_page() to invoke the cross-call.
d) Wire up global_flush_tlb_page() to the right routine based
upon CONFIG_SMP
5) It turns out that singleton batches are very common, 2 out of every
3 batch flushes have only a single entry in them.
The batch flush waiting is very expensive, both because of the poll
on sibling cpu completeion, as well as because passing the tlb batch
pointer to the sibling cpus invokes a shared memory dereference.
Therefore, in flush_tlb_pending(), if there is only one entry in
the batch perform a completely asynchronous global_flush_tlb_page()
instead.
Reported-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
2013-04-20 05:26:26 +08:00
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void arch_enter_lazy_mmu_mode(void)
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{
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sparc: Replace __get_cpu_var uses
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x). This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.
Other use cases are for storing and retrieving data from the current
processors percpu area. __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.
__get_cpu_var() is defined as :
#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.
this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.
This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset. Thereby address calculations are avoided and less registers
are used when code is generated.
At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.
The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e. using a global
register that may be set to the per cpu base.
Transformations done to __get_cpu_var()
1. Determine the address of the percpu instance of the current processor.
DEFINE_PER_CPU(int, y);
int *x = &__get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(&y);
2. Same as #1 but this time an array structure is involved.
DEFINE_PER_CPU(int, y[20]);
int *x = __get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(y);
3. Retrieve the content of the current processors instance of a per cpu
variable.
DEFINE_PER_CPU(int, y);
int x = __get_cpu_var(y)
Converts to
int x = __this_cpu_read(y);
4. Retrieve the content of a percpu struct
DEFINE_PER_CPU(struct mystruct, y);
struct mystruct x = __get_cpu_var(y);
Converts to
memcpy(&x, this_cpu_ptr(&y), sizeof(x));
5. Assignment to a per cpu variable
DEFINE_PER_CPU(int, y)
__get_cpu_var(y) = x;
Converts to
__this_cpu_write(y, x);
6. Increment/Decrement etc of a per cpu variable
DEFINE_PER_CPU(int, y);
__get_cpu_var(y)++
Converts to
__this_cpu_inc(y)
Cc: sparclinux@vger.kernel.org
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-18 01:30:54 +08:00
|
|
|
struct tlb_batch *tb = this_cpu_ptr(&tlb_batch);
|
sparc64: Fix race in TLB batch processing.
As reported by Dave Kleikamp, when we emit cross calls to do batched
TLB flush processing we have a race because we do not synchronize on
the sibling cpus completing the cross call.
So meanwhile the TLB batch can be reset (tb->tlb_nr set to zero, etc.)
and either flushes are missed or flushes will flush the wrong
addresses.
Fix this by using generic infrastructure to synchonize on the
completion of the cross call.
This first required getting the flush_tlb_pending() call out from
switch_to() which operates with locks held and interrupts disabled.
The problem is that smp_call_function_many() cannot be invoked with
IRQs disabled and this is explicitly checked for with WARN_ON_ONCE().
We get the batch processing outside of locked IRQ disabled sections by
using some ideas from the powerpc port. Namely, we only batch inside
of arch_{enter,leave}_lazy_mmu_mode() calls. If we're not in such a
region, we flush TLBs synchronously.
1) Get rid of xcall_flush_tlb_pending and per-cpu type
implementations.
2) Do TLB batch cross calls instead via:
smp_call_function_many()
tlb_pending_func()
__flush_tlb_pending()
3) Batch only in lazy mmu sequences:
a) Add 'active' member to struct tlb_batch
b) Define __HAVE_ARCH_ENTER_LAZY_MMU_MODE
c) Set 'active' in arch_enter_lazy_mmu_mode()
d) Run batch and clear 'active' in arch_leave_lazy_mmu_mode()
e) Check 'active' in tlb_batch_add_one() and do a synchronous
flush if it's clear.
4) Add infrastructure for synchronous TLB page flushes.
a) Implement __flush_tlb_page and per-cpu variants, patch
as needed.
b) Likewise for xcall_flush_tlb_page.
c) Implement smp_flush_tlb_page() to invoke the cross-call.
d) Wire up global_flush_tlb_page() to the right routine based
upon CONFIG_SMP
5) It turns out that singleton batches are very common, 2 out of every
3 batch flushes have only a single entry in them.
The batch flush waiting is very expensive, both because of the poll
on sibling cpu completeion, as well as because passing the tlb batch
pointer to the sibling cpus invokes a shared memory dereference.
Therefore, in flush_tlb_pending(), if there is only one entry in
the batch perform a completely asynchronous global_flush_tlb_page()
instead.
Reported-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
2013-04-20 05:26:26 +08:00
|
|
|
|
|
|
|
|
tb->active = 1;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
void arch_leave_lazy_mmu_mode(void)
|
|
|
|
|
{
|
sparc: Replace __get_cpu_var uses
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x). This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.
Other use cases are for storing and retrieving data from the current
processors percpu area. __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.
__get_cpu_var() is defined as :
#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.
this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.
This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset. Thereby address calculations are avoided and less registers
are used when code is generated.
At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.
The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e. using a global
register that may be set to the per cpu base.
Transformations done to __get_cpu_var()
1. Determine the address of the percpu instance of the current processor.
DEFINE_PER_CPU(int, y);
int *x = &__get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(&y);
2. Same as #1 but this time an array structure is involved.
DEFINE_PER_CPU(int, y[20]);
int *x = __get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(y);
3. Retrieve the content of the current processors instance of a per cpu
variable.
DEFINE_PER_CPU(int, y);
int x = __get_cpu_var(y)
Converts to
int x = __this_cpu_read(y);
4. Retrieve the content of a percpu struct
DEFINE_PER_CPU(struct mystruct, y);
struct mystruct x = __get_cpu_var(y);
Converts to
memcpy(&x, this_cpu_ptr(&y), sizeof(x));
5. Assignment to a per cpu variable
DEFINE_PER_CPU(int, y)
__get_cpu_var(y) = x;
Converts to
__this_cpu_write(y, x);
6. Increment/Decrement etc of a per cpu variable
DEFINE_PER_CPU(int, y);
__get_cpu_var(y)++
Converts to
__this_cpu_inc(y)
Cc: sparclinux@vger.kernel.org
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2014-08-18 01:30:54 +08:00
|
|
|
struct tlb_batch *tb = this_cpu_ptr(&tlb_batch);
|
sparc64: Fix race in TLB batch processing.
As reported by Dave Kleikamp, when we emit cross calls to do batched
TLB flush processing we have a race because we do not synchronize on
the sibling cpus completing the cross call.
So meanwhile the TLB batch can be reset (tb->tlb_nr set to zero, etc.)
and either flushes are missed or flushes will flush the wrong
addresses.
Fix this by using generic infrastructure to synchonize on the
completion of the cross call.
This first required getting the flush_tlb_pending() call out from
switch_to() which operates with locks held and interrupts disabled.
The problem is that smp_call_function_many() cannot be invoked with
IRQs disabled and this is explicitly checked for with WARN_ON_ONCE().
We get the batch processing outside of locked IRQ disabled sections by
using some ideas from the powerpc port. Namely, we only batch inside
of arch_{enter,leave}_lazy_mmu_mode() calls. If we're not in such a
region, we flush TLBs synchronously.
1) Get rid of xcall_flush_tlb_pending and per-cpu type
implementations.
2) Do TLB batch cross calls instead via:
smp_call_function_many()
tlb_pending_func()
__flush_tlb_pending()
3) Batch only in lazy mmu sequences:
a) Add 'active' member to struct tlb_batch
b) Define __HAVE_ARCH_ENTER_LAZY_MMU_MODE
c) Set 'active' in arch_enter_lazy_mmu_mode()
d) Run batch and clear 'active' in arch_leave_lazy_mmu_mode()
e) Check 'active' in tlb_batch_add_one() and do a synchronous
flush if it's clear.
4) Add infrastructure for synchronous TLB page flushes.
a) Implement __flush_tlb_page and per-cpu variants, patch
as needed.
b) Likewise for xcall_flush_tlb_page.
c) Implement smp_flush_tlb_page() to invoke the cross-call.
d) Wire up global_flush_tlb_page() to the right routine based
upon CONFIG_SMP
5) It turns out that singleton batches are very common, 2 out of every
3 batch flushes have only a single entry in them.
The batch flush waiting is very expensive, both because of the poll
on sibling cpu completeion, as well as because passing the tlb batch
pointer to the sibling cpus invokes a shared memory dereference.
Therefore, in flush_tlb_pending(), if there is only one entry in
the batch perform a completely asynchronous global_flush_tlb_page()
instead.
Reported-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
2013-04-20 05:26:26 +08:00
|
|
|
|
|
|
|
|
if (tb->tlb_nr)
|
|
|
|
|
flush_tlb_pending();
|
|
|
|
|
tb->active = 0;
|
|
|
|
|
}
|
|
|
|
|
|
2012-10-09 07:34:29 +08:00
|
|
|
static void tlb_batch_add_one(struct mm_struct *mm, unsigned long vaddr,
|
2017-02-02 08:16:36 +08:00
|
|
|
bool exec, unsigned int hugepage_shift)
|
2005-04-17 06:20:36 +08:00
|
|
|
{
|
2011-05-25 08:11:50 +08:00
|
|
|
struct tlb_batch *tb = &get_cpu_var(tlb_batch);
|
2005-04-17 06:20:36 +08:00
|
|
|
unsigned long nr;
|
|
|
|
|
|
|
|
|
|
vaddr &= PAGE_MASK;
|
2012-10-09 07:34:29 +08:00
|
|
|
if (exec)
|
2005-04-17 06:20:36 +08:00
|
|
|
vaddr |= 0x1UL;
|
|
|
|
|
|
2012-10-09 07:34:29 +08:00
|
|
|
nr = tb->tlb_nr;
|
|
|
|
|
|
|
|
|
|
if (unlikely(nr != 0 && mm != tb->mm)) {
|
|
|
|
|
flush_tlb_pending();
|
|
|
|
|
nr = 0;
|
|
|
|
|
}
|
|
|
|
|
|
sparc64: Fix race in TLB batch processing.
As reported by Dave Kleikamp, when we emit cross calls to do batched
TLB flush processing we have a race because we do not synchronize on
the sibling cpus completing the cross call.
So meanwhile the TLB batch can be reset (tb->tlb_nr set to zero, etc.)
and either flushes are missed or flushes will flush the wrong
addresses.
Fix this by using generic infrastructure to synchonize on the
completion of the cross call.
This first required getting the flush_tlb_pending() call out from
switch_to() which operates with locks held and interrupts disabled.
The problem is that smp_call_function_many() cannot be invoked with
IRQs disabled and this is explicitly checked for with WARN_ON_ONCE().
We get the batch processing outside of locked IRQ disabled sections by
using some ideas from the powerpc port. Namely, we only batch inside
of arch_{enter,leave}_lazy_mmu_mode() calls. If we're not in such a
region, we flush TLBs synchronously.
1) Get rid of xcall_flush_tlb_pending and per-cpu type
implementations.
2) Do TLB batch cross calls instead via:
smp_call_function_many()
tlb_pending_func()
__flush_tlb_pending()
3) Batch only in lazy mmu sequences:
a) Add 'active' member to struct tlb_batch
b) Define __HAVE_ARCH_ENTER_LAZY_MMU_MODE
c) Set 'active' in arch_enter_lazy_mmu_mode()
d) Run batch and clear 'active' in arch_leave_lazy_mmu_mode()
e) Check 'active' in tlb_batch_add_one() and do a synchronous
flush if it's clear.
4) Add infrastructure for synchronous TLB page flushes.
a) Implement __flush_tlb_page and per-cpu variants, patch
as needed.
b) Likewise for xcall_flush_tlb_page.
c) Implement smp_flush_tlb_page() to invoke the cross-call.
d) Wire up global_flush_tlb_page() to the right routine based
upon CONFIG_SMP
5) It turns out that singleton batches are very common, 2 out of every
3 batch flushes have only a single entry in them.
The batch flush waiting is very expensive, both because of the poll
on sibling cpu completeion, as well as because passing the tlb batch
pointer to the sibling cpus invokes a shared memory dereference.
Therefore, in flush_tlb_pending(), if there is only one entry in
the batch perform a completely asynchronous global_flush_tlb_page()
instead.
Reported-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
2013-04-20 05:26:26 +08:00
|
|
|
if (!tb->active) {
|
2017-02-02 08:16:36 +08:00
|
|
|
flush_tsb_user_page(mm, vaddr, hugepage_shift);
|
2013-06-18 22:05:36 +08:00
|
|
|
global_flush_tlb_page(mm, vaddr);
|
2013-04-25 07:52:18 +08:00
|
|
|
goto out;
|
sparc64: Fix race in TLB batch processing.
As reported by Dave Kleikamp, when we emit cross calls to do batched
TLB flush processing we have a race because we do not synchronize on
the sibling cpus completing the cross call.
So meanwhile the TLB batch can be reset (tb->tlb_nr set to zero, etc.)
and either flushes are missed or flushes will flush the wrong
addresses.
Fix this by using generic infrastructure to synchonize on the
completion of the cross call.
This first required getting the flush_tlb_pending() call out from
switch_to() which operates with locks held and interrupts disabled.
The problem is that smp_call_function_many() cannot be invoked with
IRQs disabled and this is explicitly checked for with WARN_ON_ONCE().
We get the batch processing outside of locked IRQ disabled sections by
using some ideas from the powerpc port. Namely, we only batch inside
of arch_{enter,leave}_lazy_mmu_mode() calls. If we're not in such a
region, we flush TLBs synchronously.
1) Get rid of xcall_flush_tlb_pending and per-cpu type
implementations.
2) Do TLB batch cross calls instead via:
smp_call_function_many()
tlb_pending_func()
__flush_tlb_pending()
3) Batch only in lazy mmu sequences:
a) Add 'active' member to struct tlb_batch
b) Define __HAVE_ARCH_ENTER_LAZY_MMU_MODE
c) Set 'active' in arch_enter_lazy_mmu_mode()
d) Run batch and clear 'active' in arch_leave_lazy_mmu_mode()
e) Check 'active' in tlb_batch_add_one() and do a synchronous
flush if it's clear.
4) Add infrastructure for synchronous TLB page flushes.
a) Implement __flush_tlb_page and per-cpu variants, patch
as needed.
b) Likewise for xcall_flush_tlb_page.
c) Implement smp_flush_tlb_page() to invoke the cross-call.
d) Wire up global_flush_tlb_page() to the right routine based
upon CONFIG_SMP
5) It turns out that singleton batches are very common, 2 out of every
3 batch flushes have only a single entry in them.
The batch flush waiting is very expensive, both because of the poll
on sibling cpu completeion, as well as because passing the tlb batch
pointer to the sibling cpus invokes a shared memory dereference.
Therefore, in flush_tlb_pending(), if there is only one entry in
the batch perform a completely asynchronous global_flush_tlb_page()
instead.
Reported-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com>
2013-04-20 05:26:26 +08:00
|
|
|
}
|
|
|
|
|
|
2016-03-31 02:17:13 +08:00
|
|
|
if (nr == 0) {
|
2012-10-09 07:34:29 +08:00
|
|
|
tb->mm = mm;
|
2017-02-02 08:16:36 +08:00
|
|
|
tb->hugepage_shift = hugepage_shift;
|
2016-03-31 02:17:13 +08:00
|
|
|
}
|
|
|
|
|
|
2017-02-02 08:16:36 +08:00
|
|
|
if (tb->hugepage_shift != hugepage_shift) {
|
2016-03-31 02:17:13 +08:00
|
|
|
flush_tlb_pending();
|
2017-02-02 08:16:36 +08:00
|
|
|
tb->hugepage_shift = hugepage_shift;
|
2016-03-31 02:17:13 +08:00
|
|
|
nr = 0;
|
|
|
|
|
}
|
2012-10-09 07:34:29 +08:00
|
|
|
|
|
|
|
|
tb->vaddrs[nr] = vaddr;
|
|
|
|
|
tb->tlb_nr = ++nr;
|
|
|
|
|
if (nr >= TLB_BATCH_NR)
|
|
|
|
|
flush_tlb_pending();
|
|
|
|
|
|
2013-04-25 07:52:18 +08:00
|
|
|
out:
|
2012-10-09 07:34:29 +08:00
|
|
|
put_cpu_var(tlb_batch);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr,
|
2017-02-02 08:16:36 +08:00
|
|
|
pte_t *ptep, pte_t orig, int fullmm,
|
|
|
|
|
unsigned int hugepage_shift)
|
2012-10-09 07:34:29 +08:00
|
|
|
{
|
2006-02-27 11:44:50 +08:00
|
|
|
if (tlb_type != hypervisor &&
|
|
|
|
|
pte_dirty(orig)) {
|
2005-04-17 06:20:36 +08:00
|
|
|
unsigned long paddr, pfn = pte_pfn(orig);
|
|
|
|
|
struct address_space *mapping;
|
|
|
|
|
struct page *page;
|
|
|
|
|
|
|
|
|
|
if (!pfn_valid(pfn))
|
|
|
|
|
goto no_cache_flush;
|
|
|
|
|
|
|
|
|
|
page = pfn_to_page(pfn);
|
|
|
|
|
if (PageReserved(page))
|
|
|
|
|
goto no_cache_flush;
|
|
|
|
|
|
|
|
|
|
/* A real file page? */
|
mm: fix races between swapoff and flush dcache
Thanks to commit 4b3ef9daa4fc ("mm/swap: split swap cache into 64MB
trunks"), after swapoff the address_space associated with the swap
device will be freed. So page_mapping() users which may touch the
address_space need some kind of mechanism to prevent the address_space
from being freed during accessing.
The dcache flushing functions (flush_dcache_page(), etc) in architecture
specific code may access the address_space of swap device for anonymous
pages in swap cache via page_mapping() function. But in some cases
there are no mechanisms to prevent the swap device from being swapoff,
for example,
CPU1 CPU2
__get_user_pages() swapoff()
flush_dcache_page()
mapping = page_mapping()
... exit_swap_address_space()
... kvfree(spaces)
mapping_mapped(mapping)
The address space may be accessed after being freed.
But from cachetlb.txt and Russell King, flush_dcache_page() only care
about file cache pages, for anonymous pages, flush_anon_page() should be
used. The implementation of flush_dcache_page() in all architectures
follows this too. They will check whether page_mapping() is NULL and
whether mapping_mapped() is true to determine whether to flush the
dcache immediately. And they will use interval tree (mapping->i_mmap)
to find all user space mappings. While mapping_mapped() and
mapping->i_mmap isn't used by anonymous pages in swap cache at all.
So, to fix the race between swapoff and flush dcache, __page_mapping()
is add to return the address_space for file cache pages and NULL
otherwise. All page_mapping() invoking in flush dcache functions are
replaced with page_mapping_file().
[akpm@linux-foundation.org: simplify page_mapping_file(), per Mike]
Link: http://lkml.kernel.org/r/20180305083634.15174-1-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Zankel <chris@zankel.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-06 07:24:39 +08:00
|
|
|
mapping = page_mapping_file(page);
|
2005-04-17 06:20:36 +08:00
|
|
|
if (!mapping)
|
|
|
|
|
goto no_cache_flush;
|
|
|
|
|
|
|
|
|
|
paddr = (unsigned long) page_address(page);
|
|
|
|
|
if ((paddr ^ vaddr) & (1 << 13))
|
|
|
|
|
flush_dcache_page_all(mm, page);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
no_cache_flush:
|
2012-10-09 07:34:29 +08:00
|
|
|
if (!fullmm)
|
2017-02-02 08:16:36 +08:00
|
|
|
tlb_batch_add_one(mm, vaddr, pte_exec(orig), hugepage_shift);
|
2012-10-09 07:34:29 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
|
|
|
static void tlb_batch_pmd_scan(struct mm_struct *mm, unsigned long vaddr,
|
2014-04-21 09:55:01 +08:00
|
|
|
pmd_t pmd)
|
2012-10-09 07:34:29 +08:00
|
|
|
{
|
|
|
|
|
unsigned long end;
|
|
|
|
|
pte_t *pte;
|
|
|
|
|
|
|
|
|
|
pte = pte_offset_map(&pmd, vaddr);
|
|
|
|
|
end = vaddr + HPAGE_SIZE;
|
|
|
|
|
while (vaddr < end) {
|
2014-04-21 09:55:01 +08:00
|
|
|
if (pte_val(*pte) & _PAGE_VALID) {
|
|
|
|
|
bool exec = pte_exec(*pte);
|
|
|
|
|
|
2017-04-01 06:48:53 +08:00
|
|
|
tlb_batch_add_one(mm, vaddr, exec, PAGE_SHIFT);
|
2014-04-21 09:55:01 +08:00
|
|
|
}
|
2012-10-09 07:34:29 +08:00
|
|
|
pte++;
|
|
|
|
|
vaddr += PAGE_SIZE;
|
|
|
|
|
}
|
|
|
|
|
pte_unmap(pte);
|
|
|
|
|
}
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2012-10-09 07:34:29 +08:00
|
|
|
|
2018-03-16 05:18:00 +08:00
|
|
|
static void __set_pmd_acct(struct mm_struct *mm, unsigned long addr,
|
|
|
|
|
pmd_t orig, pmd_t pmd)
|
|
|
|
|
{
|
2012-10-09 07:34:29 +08:00
|
|
|
if (mm == &init_mm)
|
2005-04-17 06:20:36 +08:00
|
|
|
return;
|
2012-10-09 07:34:29 +08:00
|
|
|
|
2013-09-27 04:45:15 +08:00
|
|
|
if ((pmd_val(pmd) ^ pmd_val(orig)) & _PAGE_PMD_HUGE) {
|
2016-09-01 04:48:19 +08:00
|
|
|
/*
|
|
|
|
|
* Note that this routine only sets pmds for THP pages.
|
|
|
|
|
* Hugetlb pages are handled elsewhere. We need to check
|
|
|
|
|
* for huge zero page. Huge zero pages are like hugetlb
|
|
|
|
|
* pages in that there is no RSS, but there is the need
|
|
|
|
|
* for TSB entries. So, huge zero page counts go into
|
|
|
|
|
* hugetlb_pte_count.
|
|
|
|
|
*/
|
|
|
|
|
if (pmd_val(pmd) & _PAGE_PMD_HUGE) {
|
|
|
|
|
if (is_huge_zero_page(pmd_page(pmd)))
|
|
|
|
|
mm->context.hugetlb_pte_count++;
|
|
|
|
|
else
|
|
|
|
|
mm->context.thp_pte_count++;
|
|
|
|
|
} else {
|
|
|
|
|
if (is_huge_zero_page(pmd_page(orig)))
|
|
|
|
|
mm->context.hugetlb_pte_count--;
|
|
|
|
|
else
|
|
|
|
|
mm->context.thp_pte_count--;
|
|
|
|
|
}
|
2013-02-20 14:34:10 +08:00
|
|
|
|
|
|
|
|
/* Do not try to allocate the TSB hash table if we
|
|
|
|
|
* don't have one already. We have various locks held
|
|
|
|
|
* and thus we'll end up doing a GFP_KERNEL allocation
|
|
|
|
|
* in an atomic context.
|
|
|
|
|
*
|
|
|
|
|
* Instead, we let the first TLB miss on a hugepage
|
|
|
|
|
* take care of this.
|
|
|
|
|
*/
|
2011-05-25 08:11:50 +08:00
|
|
|
}
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2012-10-09 07:34:29 +08:00
|
|
|
if (!pmd_none(orig)) {
|
|
|
|
|
addr &= HPAGE_MASK;
|
2013-09-27 04:45:15 +08:00
|
|
|
if (pmd_trans_huge(orig)) {
|
2014-04-21 09:55:01 +08:00
|
|
|
pte_t orig_pte = __pte(pmd_val(orig));
|
|
|
|
|
bool exec = pte_exec(orig_pte);
|
|
|
|
|
|
2017-04-01 06:48:53 +08:00
|
|
|
tlb_batch_add_one(mm, addr, exec, REAL_HPAGE_SHIFT);
|
2016-03-31 02:17:13 +08:00
|
|
|
tlb_batch_add_one(mm, addr + REAL_HPAGE_SIZE, exec,
|
2017-04-01 06:48:53 +08:00
|
|
|
REAL_HPAGE_SHIFT);
|
sparc64: Move from 4MB to 8MB huge pages.
The impetus for this is that we would like to move to 64-bit PMDs and
PGDs, but that would result in only supporting a 42-bit address space
with the current page table layout. It'd be nice to support at least
43-bits.
The reason we'd end up with only 42-bits after making PMDs and PGDs
64-bit is that we only use half-page sized PTE tables in order to make
PMDs line up to 4MB, the hardware huge page size we use.
So what we do here is we make huge pages 8MB, and fabricate them using
4MB hw TLB entries.
Facilitate this by providing a "REAL_HPAGE_SHIFT" which is used in
places that really need to operate on hardware 4MB pages.
Use full pages (512 entries) for PTE tables, and adjust PMD_SHIFT,
PGD_SHIFT, and the build time CPP test as needed. Use a CPP test to
make sure REAL_HPAGE_SHIFT and the _PAGE_SZHUGE_* we use match up.
This makes the pgtable cache completely unused, so remove the code
managing it and the state used in mm_context_t. Now we have less
spinlocks taken in the page table allocation path.
The technique we use to fabricate the 8MB pages is to transfer bit 22
from the missing virtual address into the PTEs physical address field.
That takes care of the transparent huge pages case.
For hugetlb, we fill things in at the PTE level and that code already
puts the sub huge page physical bits into the PTEs, based upon the
offset, so there is nothing special we need to do. It all just works
out.
So, a small amount of complexity in the THP case, but this code is
about to get much simpler when we move the 64-bit PMDs as we can move
away from the fancy 32-bit huge PMD encoding and just put a real PTE
value in there.
With bug fixes and help from Bob Picco.
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-26 04:48:49 +08:00
|
|
|
} else {
|
2014-04-21 09:55:01 +08:00
|
|
|
tlb_batch_pmd_scan(mm, addr, orig);
|
sparc64: Move from 4MB to 8MB huge pages.
The impetus for this is that we would like to move to 64-bit PMDs and
PGDs, but that would result in only supporting a 42-bit address space
with the current page table layout. It'd be nice to support at least
43-bits.
The reason we'd end up with only 42-bits after making PMDs and PGDs
64-bit is that we only use half-page sized PTE tables in order to make
PMDs line up to 4MB, the hardware huge page size we use.
So what we do here is we make huge pages 8MB, and fabricate them using
4MB hw TLB entries.
Facilitate this by providing a "REAL_HPAGE_SHIFT" which is used in
places that really need to operate on hardware 4MB pages.
Use full pages (512 entries) for PTE tables, and adjust PMD_SHIFT,
PGD_SHIFT, and the build time CPP test as needed. Use a CPP test to
make sure REAL_HPAGE_SHIFT and the _PAGE_SZHUGE_* we use match up.
This makes the pgtable cache completely unused, so remove the code
managing it and the state used in mm_context_t. Now we have less
spinlocks taken in the page table allocation path.
The technique we use to fabricate the 8MB pages is to transfer bit 22
from the missing virtual address into the PTEs physical address field.
That takes care of the transparent huge pages case.
For hugetlb, we fill things in at the PTE level and that code already
puts the sub huge page physical bits into the PTEs, based upon the
offset, so there is nothing special we need to do. It all just works
out.
So, a small amount of complexity in the THP case, but this code is
about to get much simpler when we move the 64-bit PMDs as we can move
away from the fancy 32-bit huge PMD encoding and just put a real PTE
value in there.
With bug fixes and help from Bob Picco.
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-26 04:48:49 +08:00
|
|
|
}
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
2012-10-09 07:34:29 +08:00
|
|
|
}
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2018-03-16 05:18:00 +08:00
|
|
|
void set_pmd_at(struct mm_struct *mm, unsigned long addr,
|
|
|
|
|
pmd_t *pmdp, pmd_t pmd)
|
|
|
|
|
{
|
|
|
|
|
pmd_t orig = *pmdp;
|
|
|
|
|
|
|
|
|
|
*pmdp = pmd;
|
|
|
|
|
__set_pmd_acct(mm, addr, orig, pmd);
|
|
|
|
|
}
|
|
|
|
|
|
2018-02-01 08:18:09 +08:00
|
|
|
static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
|
|
|
|
|
unsigned long address, pmd_t *pmdp, pmd_t pmd)
|
|
|
|
|
{
|
|
|
|
|
pmd_t old;
|
|
|
|
|
|
|
|
|
|
do {
|
|
|
|
|
old = *pmdp;
|
|
|
|
|
} while (cmpxchg64(&pmdp->pmd, old.pmd, pmd.pmd) != old.pmd);
|
2018-03-16 05:18:00 +08:00
|
|
|
__set_pmd_acct(vma->vm_mm, address, old, pmd);
|
2018-02-01 08:18:09 +08:00
|
|
|
|
|
|
|
|
return old;
|
|
|
|
|
}
|
|
|
|
|
|
2016-09-01 04:48:19 +08:00
|
|
|
/*
|
|
|
|
|
* This routine is only called when splitting a THP
|
|
|
|
|
*/
|
2018-02-01 08:18:09 +08:00
|
|
|
pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
|
2014-04-25 04:58:02 +08:00
|
|
|
pmd_t *pmdp)
|
|
|
|
|
{
|
2018-02-01 08:18:09 +08:00
|
|
|
pmd_t old, entry;
|
2014-04-25 04:58:02 +08:00
|
|
|
|
2018-02-01 08:18:09 +08:00
|
|
|
entry = __pmd(pmd_val(*pmdp) & ~_PAGE_VALID);
|
|
|
|
|
old = pmdp_establish(vma, address, pmdp, entry);
|
2014-04-25 04:58:02 +08:00
|
|
|
flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
|
2016-09-01 04:48:19 +08:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* set_pmd_at() will not be called in a way to decrement
|
|
|
|
|
* thp_pte_count when splitting a THP, so do it now.
|
|
|
|
|
* Sanity check pmd before doing the actual decrement.
|
|
|
|
|
*/
|
|
|
|
|
if ((pmd_val(entry) & _PAGE_PMD_HUGE) &&
|
|
|
|
|
!is_huge_zero_page(pmd_page(entry)))
|
|
|
|
|
(vma->vm_mm)->context.thp_pte_count--;
|
2018-02-01 08:18:09 +08:00
|
|
|
|
|
|
|
|
return old;
|
2014-04-25 04:58:02 +08:00
|
|
|
}
|
|
|
|
|
|
2013-06-06 08:14:02 +08:00
|
|
|
void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
|
|
|
|
|
pgtable_t pgtable)
|
2012-10-09 07:34:29 +08:00
|
|
|
{
|
|
|
|
|
struct list_head *lh = (struct list_head *) pgtable;
|
2005-04-17 06:20:36 +08:00
|
|
|
|
2012-10-09 07:34:29 +08:00
|
|
|
assert_spin_locked(&mm->page_table_lock);
|
2011-05-25 08:11:50 +08:00
|
|
|
|
2012-10-09 07:34:29 +08:00
|
|
|
/* FIFO */
|
2013-11-15 06:30:59 +08:00
|
|
|
if (!pmd_huge_pte(mm, pmdp))
|
2012-10-09 07:34:29 +08:00
|
|
|
INIT_LIST_HEAD(lh);
|
|
|
|
|
else
|
2013-11-15 06:30:59 +08:00
|
|
|
list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp));
|
|
|
|
|
pmd_huge_pte(mm, pmdp) = pgtable;
|
2012-10-09 07:34:29 +08:00
|
|
|
}
|
|
|
|
|
|
2013-06-06 08:14:02 +08:00
|
|
|
pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp)
|
2012-10-09 07:34:29 +08:00
|
|
|
{
|
|
|
|
|
struct list_head *lh;
|
|
|
|
|
pgtable_t pgtable;
|
|
|
|
|
|
|
|
|
|
assert_spin_locked(&mm->page_table_lock);
|
|
|
|
|
|
|
|
|
|
/* FIFO */
|
2013-11-15 06:30:59 +08:00
|
|
|
pgtable = pmd_huge_pte(mm, pmdp);
|
2012-10-09 07:34:29 +08:00
|
|
|
lh = (struct list_head *) pgtable;
|
|
|
|
|
if (list_empty(lh))
|
2013-11-15 06:30:59 +08:00
|
|
|
pmd_huge_pte(mm, pmdp) = NULL;
|
2012-10-09 07:34:29 +08:00
|
|
|
else {
|
2013-11-15 06:30:59 +08:00
|
|
|
pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next;
|
2012-10-09 07:34:29 +08:00
|
|
|
list_del(lh);
|
|
|
|
|
}
|
|
|
|
|
pte_val(pgtable[0]) = 0;
|
|
|
|
|
pte_val(pgtable[1]) = 0;
|
|
|
|
|
|
|
|
|
|
return pgtable;
|
2005-04-17 06:20:36 +08:00
|
|
|
}
|
2012-10-09 07:34:29 +08:00
|
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|