linux/include/asm-generic/pgtable.h
Greg Kroah-Hartman b24413180f 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>
2017-11-02 11:10:55 +01:00

1035 lines
28 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_GENERIC_PGTABLE_H
#define _ASM_GENERIC_PGTABLE_H
#include <linux/pfn.h>
#ifndef __ASSEMBLY__
#ifdef CONFIG_MMU
#include <linux/mm_types.h>
#include <linux/bug.h>
#include <linux/errno.h>
#if 5 - defined(__PAGETABLE_P4D_FOLDED) - defined(__PAGETABLE_PUD_FOLDED) - \
defined(__PAGETABLE_PMD_FOLDED) != CONFIG_PGTABLE_LEVELS
#error CONFIG_PGTABLE_LEVELS is not consistent with __PAGETABLE_{P4D,PUD,PMD}_FOLDED
#endif
/*
* On almost all architectures and configurations, 0 can be used as the
* upper ceiling to free_pgtables(): on many architectures it has the same
* effect as using TASK_SIZE. However, there is one configuration which
* must impose a more careful limit, to avoid freeing kernel pgtables.
*/
#ifndef USER_PGTABLES_CEILING
#define USER_PGTABLES_CEILING 0UL
#endif
#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
extern int ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep,
pte_t entry, int dirty);
#endif
#ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
extern int pmdp_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp,
pmd_t entry, int dirty);
extern int pudp_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pud_t *pudp,
pud_t entry, int dirty);
#else
static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp,
pmd_t entry, int dirty)
{
BUILD_BUG();
return 0;
}
static inline int pudp_set_access_flags(struct vm_area_struct *vma,
unsigned long address, pud_t *pudp,
pud_t entry, int dirty)
{
BUILD_BUG();
return 0;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
unsigned long address,
pte_t *ptep)
{
pte_t pte = *ptep;
int r = 1;
if (!pte_young(pte))
r = 0;
else
set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte));
return r;
}
#endif
#ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
unsigned long address,
pmd_t *pmdp)
{
pmd_t pmd = *pmdp;
int r = 1;
if (!pmd_young(pmd))
r = 0;
else
set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd));
return r;
}
#else
static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
unsigned long address,
pmd_t *pmdp)
{
BUILD_BUG();
return 0;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
int ptep_clear_flush_young(struct vm_area_struct *vma,
unsigned long address, pte_t *ptep);
#endif
#ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp);
#else
/*
* Despite relevant to THP only, this API is called from generic rmap code
* under PageTransHuge(), hence needs a dummy implementation for !THP
*/
static inline int pmdp_clear_flush_young(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp)
{
BUILD_BUG();
return 0;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
unsigned long address,
pte_t *ptep)
{
pte_t pte = *ptep;
pte_clear(mm, address, ptep);
return pte;
}
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
unsigned long address,
pmd_t *pmdp)
{
pmd_t pmd = *pmdp;
pmd_clear(pmdp);
return pmd;
}
#endif /* __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR */
#ifndef __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
unsigned long address,
pud_t *pudp)
{
pud_t pud = *pudp;
pud_clear(pudp);
return pud;
}
#endif /* __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR */
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR_FULL
static inline pmd_t pmdp_huge_get_and_clear_full(struct mm_struct *mm,
unsigned long address, pmd_t *pmdp,
int full)
{
return pmdp_huge_get_and_clear(mm, address, pmdp);
}
#endif
#ifndef __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR_FULL
static inline pud_t pudp_huge_get_and_clear_full(struct mm_struct *mm,
unsigned long address, pud_t *pudp,
int full)
{
return pudp_huge_get_and_clear(mm, address, pudp);
}
#endif
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
unsigned long address, pte_t *ptep,
int full)
{
pte_t pte;
pte = ptep_get_and_clear(mm, address, ptep);
return pte;
}
#endif
/*
* Some architectures may be able to avoid expensive synchronization
* primitives when modifications are made to PTE's which are already
* not present, or in the process of an address space destruction.
*/
#ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL
static inline void pte_clear_not_present_full(struct mm_struct *mm,
unsigned long address,
pte_t *ptep,
int full)
{
pte_clear(mm, address, ptep);
}
#endif
#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
extern pte_t ptep_clear_flush(struct vm_area_struct *vma,
unsigned long address,
pte_t *ptep);
#endif
#ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH
extern pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma,
unsigned long address,
pmd_t *pmdp);
extern pud_t pudp_huge_clear_flush(struct vm_area_struct *vma,
unsigned long address,
pud_t *pudp);
#endif
#ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
struct mm_struct;
static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
{
pte_t old_pte = *ptep;
set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
}
#endif
#ifndef pte_savedwrite
#define pte_savedwrite pte_write
#endif
#ifndef pte_mk_savedwrite
#define pte_mk_savedwrite pte_mkwrite
#endif
#ifndef pte_clear_savedwrite
#define pte_clear_savedwrite pte_wrprotect
#endif
#ifndef pmd_savedwrite
#define pmd_savedwrite pmd_write
#endif
#ifndef pmd_mk_savedwrite
#define pmd_mk_savedwrite pmd_mkwrite
#endif
#ifndef pmd_clear_savedwrite
#define pmd_clear_savedwrite pmd_wrprotect
#endif
#ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline void pmdp_set_wrprotect(struct mm_struct *mm,
unsigned long address, pmd_t *pmdp)
{
pmd_t old_pmd = *pmdp;
set_pmd_at(mm, address, pmdp, pmd_wrprotect(old_pmd));
}
#else
static inline void pmdp_set_wrprotect(struct mm_struct *mm,
unsigned long address, pmd_t *pmdp)
{
BUILD_BUG();
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
#ifndef __HAVE_ARCH_PUDP_SET_WRPROTECT
#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
static inline void pudp_set_wrprotect(struct mm_struct *mm,
unsigned long address, pud_t *pudp)
{
pud_t old_pud = *pudp;
set_pud_at(mm, address, pudp, pud_wrprotect(old_pud));
}
#else
static inline void pudp_set_wrprotect(struct mm_struct *mm,
unsigned long address, pud_t *pudp)
{
BUILD_BUG();
}
#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
#endif
#ifndef pmdp_collapse_flush
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp);
#else
static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
unsigned long address,
pmd_t *pmdp)
{
BUILD_BUG();
return *pmdp;
}
#define pmdp_collapse_flush pmdp_collapse_flush
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
#ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
pgtable_t pgtable);
#endif
#ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
#endif
#ifndef __HAVE_ARCH_PMDP_INVALIDATE
extern void pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp);
#endif
#ifndef __HAVE_ARCH_PMDP_HUGE_SPLIT_PREPARE
static inline void pmdp_huge_split_prepare(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp)
{
}
#endif
#ifndef __HAVE_ARCH_PTE_SAME
static inline int pte_same(pte_t pte_a, pte_t pte_b)
{
return pte_val(pte_a) == pte_val(pte_b);
}
#endif
#ifndef __HAVE_ARCH_PTE_UNUSED
/*
* Some architectures provide facilities to virtualization guests
* so that they can flag allocated pages as unused. This allows the
* host to transparently reclaim unused pages. This function returns
* whether the pte's page is unused.
*/
static inline int pte_unused(pte_t pte)
{
return 0;
}
#endif
#ifndef pte_access_permitted
#define pte_access_permitted(pte, write) \
(pte_present(pte) && (!(write) || pte_write(pte)))
#endif
#ifndef pmd_access_permitted
#define pmd_access_permitted(pmd, write) \
(pmd_present(pmd) && (!(write) || pmd_write(pmd)))
#endif
#ifndef pud_access_permitted
#define pud_access_permitted(pud, write) \
(pud_present(pud) && (!(write) || pud_write(pud)))
#endif
#ifndef p4d_access_permitted
#define p4d_access_permitted(p4d, write) \
(p4d_present(p4d) && (!(write) || p4d_write(p4d)))
#endif
#ifndef pgd_access_permitted
#define pgd_access_permitted(pgd, write) \
(pgd_present(pgd) && (!(write) || pgd_write(pgd)))
#endif
#ifndef __HAVE_ARCH_PMD_SAME
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
{
return pmd_val(pmd_a) == pmd_val(pmd_b);
}
static inline int pud_same(pud_t pud_a, pud_t pud_b)
{
return pud_val(pud_a) == pud_val(pud_b);
}
#else /* CONFIG_TRANSPARENT_HUGEPAGE */
static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
{
BUILD_BUG();
return 0;
}
static inline int pud_same(pud_t pud_a, pud_t pud_b)
{
BUILD_BUG();
return 0;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#endif
#ifndef __HAVE_ARCH_PGD_OFFSET_GATE
#define pgd_offset_gate(mm, addr) pgd_offset(mm, addr)
#endif
#ifndef __HAVE_ARCH_MOVE_PTE
#define move_pte(pte, prot, old_addr, new_addr) (pte)
#endif
#ifndef pte_accessible
# define pte_accessible(mm, pte) ((void)(pte), 1)
#endif
#ifndef flush_tlb_fix_spurious_fault
#define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
#endif
#ifndef pgprot_noncached
#define pgprot_noncached(prot) (prot)
#endif
#ifndef pgprot_writecombine
#define pgprot_writecombine pgprot_noncached
#endif
#ifndef pgprot_writethrough
#define pgprot_writethrough pgprot_noncached
#endif
#ifndef pgprot_device
#define pgprot_device pgprot_noncached
#endif
#ifndef pgprot_modify
#define pgprot_modify pgprot_modify
static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
{
if (pgprot_val(oldprot) == pgprot_val(pgprot_noncached(oldprot)))
newprot = pgprot_noncached(newprot);
if (pgprot_val(oldprot) == pgprot_val(pgprot_writecombine(oldprot)))
newprot = pgprot_writecombine(newprot);
if (pgprot_val(oldprot) == pgprot_val(pgprot_device(oldprot)))
newprot = pgprot_device(newprot);
return newprot;
}
#endif
/*
* When walking page tables, get the address of the next boundary,
* or the end address of the range if that comes earlier. Although no
* vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
*/
#define pgd_addr_end(addr, end) \
({ unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK; \
(__boundary - 1 < (end) - 1)? __boundary: (end); \
})
#ifndef p4d_addr_end
#define p4d_addr_end(addr, end) \
({ unsigned long __boundary = ((addr) + P4D_SIZE) & P4D_MASK; \
(__boundary - 1 < (end) - 1)? __boundary: (end); \
})
#endif
#ifndef pud_addr_end
#define pud_addr_end(addr, end) \
({ unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK; \
(__boundary - 1 < (end) - 1)? __boundary: (end); \
})
#endif
#ifndef pmd_addr_end
#define pmd_addr_end(addr, end) \
({ unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK; \
(__boundary - 1 < (end) - 1)? __boundary: (end); \
})
#endif
/*
* When walking page tables, we usually want to skip any p?d_none entries;
* and any p?d_bad entries - reporting the error before resetting to none.
* Do the tests inline, but report and clear the bad entry in mm/memory.c.
*/
void pgd_clear_bad(pgd_t *);
void p4d_clear_bad(p4d_t *);
void pud_clear_bad(pud_t *);
void pmd_clear_bad(pmd_t *);
static inline int pgd_none_or_clear_bad(pgd_t *pgd)
{
if (pgd_none(*pgd))
return 1;
if (unlikely(pgd_bad(*pgd))) {
pgd_clear_bad(pgd);
return 1;
}
return 0;
}
static inline int p4d_none_or_clear_bad(p4d_t *p4d)
{
if (p4d_none(*p4d))
return 1;
if (unlikely(p4d_bad(*p4d))) {
p4d_clear_bad(p4d);
return 1;
}
return 0;
}
static inline int pud_none_or_clear_bad(pud_t *pud)
{
if (pud_none(*pud))
return 1;
if (unlikely(pud_bad(*pud))) {
pud_clear_bad(pud);
return 1;
}
return 0;
}
static inline int pmd_none_or_clear_bad(pmd_t *pmd)
{
if (pmd_none(*pmd))
return 1;
if (unlikely(pmd_bad(*pmd))) {
pmd_clear_bad(pmd);
return 1;
}
return 0;
}
static inline pte_t __ptep_modify_prot_start(struct mm_struct *mm,
unsigned long addr,
pte_t *ptep)
{
/*
* Get the current pte state, but zero it out to make it
* non-present, preventing the hardware from asynchronously
* updating it.
*/
return ptep_get_and_clear(mm, addr, ptep);
}
static inline void __ptep_modify_prot_commit(struct mm_struct *mm,
unsigned long addr,
pte_t *ptep, pte_t pte)
{
/*
* The pte is non-present, so there's no hardware state to
* preserve.
*/
set_pte_at(mm, addr, ptep, pte);
}
#ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
/*
* Start a pte protection read-modify-write transaction, which
* protects against asynchronous hardware modifications to the pte.
* The intention is not to prevent the hardware from making pte
* updates, but to prevent any updates it may make from being lost.
*
* This does not protect against other software modifications of the
* pte; the appropriate pte lock must be held over the transation.
*
* Note that this interface is intended to be batchable, meaning that
* ptep_modify_prot_commit may not actually update the pte, but merely
* queue the update to be done at some later time. The update must be
* actually committed before the pte lock is released, however.
*/
static inline pte_t ptep_modify_prot_start(struct mm_struct *mm,
unsigned long addr,
pte_t *ptep)
{
return __ptep_modify_prot_start(mm, addr, ptep);
}
/*
* Commit an update to a pte, leaving any hardware-controlled bits in
* the PTE unmodified.
*/
static inline void ptep_modify_prot_commit(struct mm_struct *mm,
unsigned long addr,
pte_t *ptep, pte_t pte)
{
__ptep_modify_prot_commit(mm, addr, ptep, pte);
}
#endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
#endif /* CONFIG_MMU */
/*
* No-op macros that just return the current protection value. Defined here
* because these macros can be used used even if CONFIG_MMU is not defined.
*/
#ifndef pgprot_encrypted
#define pgprot_encrypted(prot) (prot)
#endif
#ifndef pgprot_decrypted
#define pgprot_decrypted(prot) (prot)
#endif
/*
* A facility to provide lazy MMU batching. This allows PTE updates and
* page invalidations to be delayed until a call to leave lazy MMU mode
* is issued. Some architectures may benefit from doing this, and it is
* beneficial for both shadow and direct mode hypervisors, which may batch
* the PTE updates which happen during this window. Note that using this
* interface requires that read hazards be removed from the code. A read
* hazard could result in the direct mode hypervisor case, since the actual
* write to the page tables may not yet have taken place, so reads though
* a raw PTE pointer after it has been modified are not guaranteed to be
* up to date. This mode can only be entered and left under the protection of
* the page table locks for all page tables which may be modified. In the UP
* case, this is required so that preemption is disabled, and in the SMP case,
* it must synchronize the delayed page table writes properly on other CPUs.
*/
#ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
#define arch_enter_lazy_mmu_mode() do {} while (0)
#define arch_leave_lazy_mmu_mode() do {} while (0)
#define arch_flush_lazy_mmu_mode() do {} while (0)
#endif
/*
* A facility to provide batching of the reload of page tables and
* other process state with the actual context switch code for
* paravirtualized guests. By convention, only one of the batched
* update (lazy) modes (CPU, MMU) should be active at any given time,
* entry should never be nested, and entry and exits should always be
* paired. This is for sanity of maintaining and reasoning about the
* kernel code. In this case, the exit (end of the context switch) is
* in architecture-specific code, and so doesn't need a generic
* definition.
*/
#ifndef __HAVE_ARCH_START_CONTEXT_SWITCH
#define arch_start_context_switch(prev) do {} while (0)
#endif
#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
#ifndef CONFIG_ARCH_ENABLE_THP_MIGRATION
static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
{
return pmd;
}
static inline int pmd_swp_soft_dirty(pmd_t pmd)
{
return 0;
}
static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
{
return pmd;
}
#endif
#else /* !CONFIG_HAVE_ARCH_SOFT_DIRTY */
static inline int pte_soft_dirty(pte_t pte)
{
return 0;
}
static inline int pmd_soft_dirty(pmd_t pmd)
{
return 0;
}
static inline pte_t pte_mksoft_dirty(pte_t pte)
{
return pte;
}
static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
{
return pmd;
}
static inline pte_t pte_clear_soft_dirty(pte_t pte)
{
return pte;
}
static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
{
return pmd;
}
static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
{
return pte;
}
static inline int pte_swp_soft_dirty(pte_t pte)
{
return 0;
}
static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
{
return pte;
}
static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
{
return pmd;
}
static inline int pmd_swp_soft_dirty(pmd_t pmd)
{
return 0;
}
static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
{
return pmd;
}
#endif
#ifndef __HAVE_PFNMAP_TRACKING
/*
* Interfaces that can be used by architecture code to keep track of
* memory type of pfn mappings specified by the remap_pfn_range,
* vm_insert_pfn.
*/
/*
* track_pfn_remap is called when a _new_ pfn mapping is being established
* by remap_pfn_range() for physical range indicated by pfn and size.
*/
static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
unsigned long pfn, unsigned long addr,
unsigned long size)
{
return 0;
}
/*
* track_pfn_insert is called when a _new_ single pfn is established
* by vm_insert_pfn().
*/
static inline void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
pfn_t pfn)
{
}
/*
* track_pfn_copy is called when vma that is covering the pfnmap gets
* copied through copy_page_range().
*/
static inline int track_pfn_copy(struct vm_area_struct *vma)
{
return 0;
}
/*
* untrack_pfn is called while unmapping a pfnmap for a region.
* untrack can be called for a specific region indicated by pfn and size or
* can be for the entire vma (in which case pfn, size are zero).
*/
static inline void untrack_pfn(struct vm_area_struct *vma,
unsigned long pfn, unsigned long size)
{
}
/*
* untrack_pfn_moved is called while mremapping a pfnmap for a new region.
*/
static inline void untrack_pfn_moved(struct vm_area_struct *vma)
{
}
#else
extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
unsigned long pfn, unsigned long addr,
unsigned long size);
extern void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
pfn_t pfn);
extern int track_pfn_copy(struct vm_area_struct *vma);
extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
unsigned long size);
extern void untrack_pfn_moved(struct vm_area_struct *vma);
#endif
#ifdef __HAVE_COLOR_ZERO_PAGE
static inline int is_zero_pfn(unsigned long pfn)
{
extern unsigned long zero_pfn;
unsigned long offset_from_zero_pfn = pfn - zero_pfn;
return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT);
}
#define my_zero_pfn(addr) page_to_pfn(ZERO_PAGE(addr))
#else
static inline int is_zero_pfn(unsigned long pfn)
{
extern unsigned long zero_pfn;
return pfn == zero_pfn;
}
static inline unsigned long my_zero_pfn(unsigned long addr)
{
extern unsigned long zero_pfn;
return zero_pfn;
}
#endif
#ifdef CONFIG_MMU
#ifndef CONFIG_TRANSPARENT_HUGEPAGE
static inline int pmd_trans_huge(pmd_t pmd)
{
return 0;
}
#ifndef __HAVE_ARCH_PMD_WRITE
static inline int pmd_write(pmd_t pmd)
{
BUG();
return 0;
}
#endif /* __HAVE_ARCH_PMD_WRITE */
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
#if !defined(CONFIG_TRANSPARENT_HUGEPAGE) || \
(defined(CONFIG_TRANSPARENT_HUGEPAGE) && \
!defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD))
static inline int pud_trans_huge(pud_t pud)
{
return 0;
}
#endif
#ifndef pmd_read_atomic
static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
{
/*
* Depend on compiler for an atomic pmd read. NOTE: this is
* only going to work, if the pmdval_t isn't larger than
* an unsigned long.
*/
return *pmdp;
}
#endif
#ifndef arch_needs_pgtable_deposit
#define arch_needs_pgtable_deposit() (false)
#endif
/*
* This function is meant to be used by sites walking pagetables with
* the mmap_sem hold in read mode to protect against MADV_DONTNEED and
* transhuge page faults. MADV_DONTNEED can convert a transhuge pmd
* into a null pmd and the transhuge page fault can convert a null pmd
* into an hugepmd or into a regular pmd (if the hugepage allocation
* fails). While holding the mmap_sem in read mode the pmd becomes
* stable and stops changing under us only if it's not null and not a
* transhuge pmd. When those races occurs and this function makes a
* difference vs the standard pmd_none_or_clear_bad, the result is
* undefined so behaving like if the pmd was none is safe (because it
* can return none anyway). The compiler level barrier() is critically
* important to compute the two checks atomically on the same pmdval.
*
* For 32bit kernels with a 64bit large pmd_t this automatically takes
* care of reading the pmd atomically to avoid SMP race conditions
* against pmd_populate() when the mmap_sem is hold for reading by the
* caller (a special atomic read not done by "gcc" as in the generic
* version above, is also needed when THP is disabled because the page
* fault can populate the pmd from under us).
*/
static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd)
{
pmd_t pmdval = pmd_read_atomic(pmd);
/*
* The barrier will stabilize the pmdval in a register or on
* the stack so that it will stop changing under the code.
*
* When CONFIG_TRANSPARENT_HUGEPAGE=y on x86 32bit PAE,
* pmd_read_atomic is allowed to return a not atomic pmdval
* (for example pointing to an hugepage that has never been
* mapped in the pmd). The below checks will only care about
* the low part of the pmd with 32bit PAE x86 anyway, with the
* exception of pmd_none(). So the important thing is that if
* the low part of the pmd is found null, the high part will
* be also null or the pmd_none() check below would be
* confused.
*/
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
barrier();
#endif
/*
* !pmd_present() checks for pmd migration entries
*
* The complete check uses is_pmd_migration_entry() in linux/swapops.h
* But using that requires moving current function and pmd_trans_unstable()
* to linux/swapops.h to resovle dependency, which is too much code move.
*
* !pmd_present() is equivalent to is_pmd_migration_entry() currently,
* because !pmd_present() pages can only be under migration not swapped
* out.
*
* pmd_none() is preseved for future condition checks on pmd migration
* entries and not confusing with this function name, although it is
* redundant with !pmd_present().
*/
if (pmd_none(pmdval) || pmd_trans_huge(pmdval) ||
(IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION) && !pmd_present(pmdval)))
return 1;
if (unlikely(pmd_bad(pmdval))) {
pmd_clear_bad(pmd);
return 1;
}
return 0;
}
/*
* This is a noop if Transparent Hugepage Support is not built into
* the kernel. Otherwise it is equivalent to
* pmd_none_or_trans_huge_or_clear_bad(), and shall only be called in
* places that already verified the pmd is not none and they want to
* walk ptes while holding the mmap sem in read mode (write mode don't
* need this). If THP is not enabled, the pmd can't go away under the
* code even if MADV_DONTNEED runs, but if THP is enabled we need to
* run a pmd_trans_unstable before walking the ptes after
* split_huge_page_pmd returns (because it may have run when the pmd
* become null, but then a page fault can map in a THP and not a
* regular page).
*/
static inline int pmd_trans_unstable(pmd_t *pmd)
{
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
return pmd_none_or_trans_huge_or_clear_bad(pmd);
#else
return 0;
#endif
}
#ifndef CONFIG_NUMA_BALANCING
/*
* Technically a PTE can be PROTNONE even when not doing NUMA balancing but
* the only case the kernel cares is for NUMA balancing and is only ever set
* when the VMA is accessible. For PROT_NONE VMAs, the PTEs are not marked
* _PAGE_PROTNONE so by by default, implement the helper as "always no". It
* is the responsibility of the caller to distinguish between PROT_NONE
* protections and NUMA hinting fault protections.
*/
static inline int pte_protnone(pte_t pte)
{
return 0;
}
static inline int pmd_protnone(pmd_t pmd)
{
return 0;
}
#endif /* CONFIG_NUMA_BALANCING */
#endif /* CONFIG_MMU */
#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
#ifndef __PAGETABLE_P4D_FOLDED
int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot);
int p4d_clear_huge(p4d_t *p4d);
#else
static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
{
return 0;
}
static inline int p4d_clear_huge(p4d_t *p4d)
{
return 0;
}
#endif /* !__PAGETABLE_P4D_FOLDED */
int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot);
int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot);
int pud_clear_huge(pud_t *pud);
int pmd_clear_huge(pmd_t *pmd);
#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
{
return 0;
}
static inline int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
{
return 0;
}
static inline int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
{
return 0;
}
static inline int p4d_clear_huge(p4d_t *p4d)
{
return 0;
}
static inline int pud_clear_huge(pud_t *pud)
{
return 0;
}
static inline int pmd_clear_huge(pmd_t *pmd)
{
return 0;
}
#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
#ifndef __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/*
* ARCHes with special requirements for evicting THP backing TLB entries can
* implement this. Otherwise also, it can help optimize normal TLB flush in
* THP regime. stock flush_tlb_range() typically has optimization to nuke the
* entire TLB TLB if flush span is greater than a threshold, which will
* likely be true for a single huge page. Thus a single thp flush will
* invalidate the entire TLB which is not desitable.
* e.g. see arch/arc: flush_pmd_tlb_range
*/
#define flush_pmd_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end)
#define flush_pud_tlb_range(vma, addr, end) flush_tlb_range(vma, addr, end)
#else
#define flush_pmd_tlb_range(vma, addr, end) BUILD_BUG()
#define flush_pud_tlb_range(vma, addr, end) BUILD_BUG()
#endif
#endif
struct file;
int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t *vma_prot);
#endif /* !__ASSEMBLY__ */
#ifndef io_remap_pfn_range
#define io_remap_pfn_range remap_pfn_range
#endif
#ifndef has_transparent_hugepage
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define has_transparent_hugepage() 1
#else
#define has_transparent_hugepage() 0
#endif
#endif
#endif /* _ASM_GENERIC_PGTABLE_H */