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![David Hildenbrand](/assets/img/avatar_default.png)
Patch series "mm: COW fixes part 3: reliable GUP R/W FOLL_GET of anonymous pages", v2. This series fixes memory corruptions when a GUP R/W reference (FOLL_WRITE | FOLL_GET) was taken on an anonymous page and COW logic fails to detect exclusivity of the page to then replacing the anonymous page by a copy in the page table: The GUP reference lost synchronicity with the pages mapped into the page tables. This series focuses on x86, arm64, s390x and ppc64/book3s -- other architectures are fairly easy to support by implementing __HAVE_ARCH_PTE_SWP_EXCLUSIVE. This primarily fixes the O_DIRECT memory corruptions that can happen on concurrent swapout, whereby we lose DMA reads to a page (modifying the user page by writing to it). O_DIRECT currently uses FOLL_GET for short-term (!FOLL_LONGTERM) DMA from/to a user page. In the long run, we want to convert it to properly use FOLL_PIN, and John is working on it, but that might take a while and might not be easy to backport. In the meantime, let's restore what used to work before we started modifying our COW logic: make R/W FOLL_GET references reliable as long as there is no fork() after GUP involved. This is just the natural follow-up of part 2, that will also further reduce "wrong COW" on the swapin path, for example, when we cannot remove a page from the swapcache due to concurrent writeback, or if we have two threads faulting on the same swapped-out page. Fixing O_DIRECT is just a nice side-product This issue, including other related COW issues, has been summarized in [3] under 2): " 2. Intra Process Memory Corruptions due to Wrong COW (FOLL_GET) It was discovered that we can create a memory corruption by reading a file via O_DIRECT to a part (e.g., first 512 bytes) of a page, concurrently writing to an unrelated part (e.g., last byte) of the same page, and concurrently write-protecting the page via clear_refs SOFTDIRTY tracking [6]. For the reproducer, the issue is that O_DIRECT grabs a reference of the target page (via FOLL_GET) and clear_refs write-protects the relevant page table entry. On successive write access to the page from the process itself, we wrongly COW the page when resolving the write fault, resulting in a loss of synchronicity and consequently a memory corruption. While some people might think that using clear_refs in this combination is a corner cases, it turns out to be a more generic problem unfortunately. For example, it was just recently discovered that we can similarly create a memory corruption without clear_refs, simply by concurrently swapping out the buffer pages [7]. Note that we nowadays even use the swap infrastructure in Linux without an actual swap disk/partition: the prime example is zram which is enabled as default under Fedora [10]. The root issue is that a write-fault on a page that has additional references results in a COW and thereby a loss of synchronicity and consequently a memory corruption if two parties believe they are referencing the same page. " We don't particularly care about R/O FOLL_GET references: they were never reliable and O_DIRECT doesn't expect to observe modifications from a page after DMA was started. Note that: * this only fixes the issue on x86, arm64, s390x and ppc64/book3s ("enterprise architectures"). Other architectures have to implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE to achieve the same. * this does *not * consider any kind of fork() after taking the reference: fork() after GUP never worked reliably with FOLL_GET. * Not losing PG_anon_exclusive during swapout was the last remaining piece. KSM already makes sure that there are no other references on a page before considering it for sharing. Page migration maintains PG_anon_exclusive and simply fails when there are additional references (freezing the refcount fails). Only swapout code dropped the PG_anon_exclusive flag because it requires more work to remember + restore it. With this series in place, most COW issues of [3] are fixed on said architectures. Other architectures can implement __HAVE_ARCH_PTE_SWP_EXCLUSIVE fairly easily. [1] https://lkml.kernel.org/r/20220329160440.193848-1-david@redhat.com [2] https://lkml.kernel.org/r/20211217113049.23850-1-david@redhat.com [3] https://lore.kernel.org/r/3ae33b08-d9ef-f846-56fb-645e3b9b4c66@redhat.com This patch (of 8): Currently, we clear PG_anon_exclusive in try_to_unmap() and forget about it. We do this, to keep fork() logic on swap entries easy and efficient: for example, if we wouldn't clear it when unmapping, we'd have to lookup the page in the swapcache for each and every swap entry during fork() and clear PG_anon_exclusive if set. Instead, we want to store that information directly in the swap pte, protected by the page table lock, similarly to how we handle SWP_MIGRATION_READ_EXCLUSIVE for migration entries. However, for actual swap entries, we don't want to mess with the swap type (e.g., still one bit) because it overcomplicates swap code. In try_to_unmap(), we already reject to unmap in case the page might be pinned, because we must not lose PG_anon_exclusive on pinned pages ever. Checking if there are other unexpected references reliably *before* completely unmapping a page is unfortunately not really possible: THP heavily overcomplicate the situation. Once fully unmapped it's easier -- we, for example, make sure that there are no unexpected references *after* unmapping a page before starting writeback on that page. So, we currently might end up unmapping a page and clearing PG_anon_exclusive if that page has additional references, for example, due to a FOLL_GET. do_swap_page() has to re-determine if a page is exclusive, which will easily fail if there are other references on a page, most prominently GUP references via FOLL_GET. This can currently result in memory corruptions when taking a FOLL_GET | FOLL_WRITE reference on a page even when fork() is never involved: try_to_unmap() will succeed, and when refaulting the page, it cannot be marked exclusive and will get replaced by a copy in the page tables on the next write access, resulting in writes via the GUP reference to the page being lost. In an ideal world, everybody that uses GUP and wants to modify page content, such as O_DIRECT, would properly use FOLL_PIN. However, that conversion will take a while. It's easier to fix what used to work in the past (FOLL_GET | FOLL_WRITE) remembering PG_anon_exclusive. In addition, by remembering PG_anon_exclusive we can further reduce unnecessary COW in some cases, so it's the natural thing to do. So let's transfer the PG_anon_exclusive information to the swap pte and store it via an architecture-dependant pte bit; use that information when restoring the swap pte in do_swap_page() and unuse_pte(). During fork(), we simply have to clear the pte bit and are done. Of course, there is one corner case to handle: swap backends that don't support concurrent page modifications while the page is under writeback. Special case these, and drop the exclusive marker. Add a comment why that is just fine (also, reuse_swap_page() would have done the same in the past). In the future, we'll hopefully have all architectures support __HAVE_ARCH_PTE_SWP_EXCLUSIVE, such that we can get rid of the empty stubs and the define completely. Then, we can also convert SWP_MIGRATION_READ_EXCLUSIVE. For architectures it's fairly easy to support: either simply use a yet unused pte bit that can be used for swap entries, steal one from the arch type bits if they exceed 5, or steal one from the offset bits. Note: R/O FOLL_GET references were never really reliable, especially when taking one on a shared page and then writing to the page (e.g., GUP after fork()). FOLL_GET, including R/W references, were never really reliable once fork was involved (e.g., GUP before fork(), GUP during fork()). KSM steps back in case it stumbles over unexpected references and is, therefore, fine. [david@redhat.com: fix SWP_STABLE_WRITES test] Link: https://lkml.kernel.org/r/ac725bcb-313a-4fff-250a-68ba9a8f85fb@redhat.comLink: https://lkml.kernel.org/r/20220329164329.208407-1-david@redhat.com Link: https://lkml.kernel.org/r/20220329164329.208407-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Jann Horn <jannh@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nadav Amit <namit@vmware.com> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <guro@fb.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Peter Xu <peterx@redhat.com> Cc: Don Dutile <ddutile@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Liang Zhang <zhangliang5@huawei.com> Cc: Pedro Demarchi Gomes <pedrodemargomes@gmail.com> Cc: Oded Gabbay <oded.gabbay@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
1673 lines
45 KiB
C
1673 lines
45 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_PGTABLE_H
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#define _LINUX_PGTABLE_H
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#include <linux/pfn.h>
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#include <asm/pgtable.h>
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#ifndef __ASSEMBLY__
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#ifdef CONFIG_MMU
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#include <linux/mm_types.h>
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#include <linux/bug.h>
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#include <linux/errno.h>
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#include <asm-generic/pgtable_uffd.h>
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#if 5 - defined(__PAGETABLE_P4D_FOLDED) - defined(__PAGETABLE_PUD_FOLDED) - \
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defined(__PAGETABLE_PMD_FOLDED) != CONFIG_PGTABLE_LEVELS
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#error CONFIG_PGTABLE_LEVELS is not consistent with __PAGETABLE_{P4D,PUD,PMD}_FOLDED
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#endif
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/*
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* On almost all architectures and configurations, 0 can be used as the
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* upper ceiling to free_pgtables(): on many architectures it has the same
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* effect as using TASK_SIZE. However, there is one configuration which
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* must impose a more careful limit, to avoid freeing kernel pgtables.
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*/
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#ifndef USER_PGTABLES_CEILING
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#define USER_PGTABLES_CEILING 0UL
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#endif
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/*
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* This defines the first usable user address. Platforms
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* can override its value with custom FIRST_USER_ADDRESS
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* defined in their respective <asm/pgtable.h>.
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*/
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#ifndef FIRST_USER_ADDRESS
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#define FIRST_USER_ADDRESS 0UL
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#endif
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/*
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* This defines the generic helper for accessing PMD page
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* table page. Although platforms can still override this
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* via their respective <asm/pgtable.h>.
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*/
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#ifndef pmd_pgtable
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#define pmd_pgtable(pmd) pmd_page(pmd)
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#endif
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/*
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* A page table page can be thought of an array like this: pXd_t[PTRS_PER_PxD]
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*
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* The pXx_index() functions return the index of the entry in the page
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* table page which would control the given virtual address
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*
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* As these functions may be used by the same code for different levels of
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* the page table folding, they are always available, regardless of
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* CONFIG_PGTABLE_LEVELS value. For the folded levels they simply return 0
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* because in such cases PTRS_PER_PxD equals 1.
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*/
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static inline unsigned long pte_index(unsigned long address)
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{
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return (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
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}
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#define pte_index pte_index
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#ifndef pmd_index
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static inline unsigned long pmd_index(unsigned long address)
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{
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return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
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}
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#define pmd_index pmd_index
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#endif
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#ifndef pud_index
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static inline unsigned long pud_index(unsigned long address)
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{
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return (address >> PUD_SHIFT) & (PTRS_PER_PUD - 1);
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}
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#define pud_index pud_index
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#endif
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#ifndef pgd_index
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/* Must be a compile-time constant, so implement it as a macro */
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#define pgd_index(a) (((a) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
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#endif
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#ifndef pte_offset_kernel
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static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long address)
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{
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return (pte_t *)pmd_page_vaddr(*pmd) + pte_index(address);
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}
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#define pte_offset_kernel pte_offset_kernel
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#endif
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#if defined(CONFIG_HIGHPTE)
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#define pte_offset_map(dir, address) \
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((pte_t *)kmap_atomic(pmd_page(*(dir))) + \
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pte_index((address)))
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#define pte_unmap(pte) kunmap_atomic((pte))
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#else
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#define pte_offset_map(dir, address) pte_offset_kernel((dir), (address))
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#define pte_unmap(pte) ((void)(pte)) /* NOP */
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#endif
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/* Find an entry in the second-level page table.. */
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#ifndef pmd_offset
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static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
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{
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return pud_pgtable(*pud) + pmd_index(address);
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}
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#define pmd_offset pmd_offset
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#endif
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#ifndef pud_offset
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static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
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{
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return p4d_pgtable(*p4d) + pud_index(address);
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}
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#define pud_offset pud_offset
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#endif
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static inline pgd_t *pgd_offset_pgd(pgd_t *pgd, unsigned long address)
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{
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return (pgd + pgd_index(address));
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};
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/*
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* a shortcut to get a pgd_t in a given mm
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*/
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#ifndef pgd_offset
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#define pgd_offset(mm, address) pgd_offset_pgd((mm)->pgd, (address))
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#endif
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/*
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* a shortcut which implies the use of the kernel's pgd, instead
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* of a process's
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*/
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#ifndef pgd_offset_k
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#define pgd_offset_k(address) pgd_offset(&init_mm, (address))
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#endif
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/*
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* In many cases it is known that a virtual address is mapped at PMD or PTE
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* level, so instead of traversing all the page table levels, we can get a
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* pointer to the PMD entry in user or kernel page table or translate a virtual
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* address to the pointer in the PTE in the kernel page tables with simple
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* helpers.
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*/
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static inline pmd_t *pmd_off(struct mm_struct *mm, unsigned long va)
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{
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return pmd_offset(pud_offset(p4d_offset(pgd_offset(mm, va), va), va), va);
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}
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static inline pmd_t *pmd_off_k(unsigned long va)
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{
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return pmd_offset(pud_offset(p4d_offset(pgd_offset_k(va), va), va), va);
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}
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static inline pte_t *virt_to_kpte(unsigned long vaddr)
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{
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pmd_t *pmd = pmd_off_k(vaddr);
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return pmd_none(*pmd) ? NULL : pte_offset_kernel(pmd, vaddr);
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}
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#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
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extern int ptep_set_access_flags(struct vm_area_struct *vma,
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unsigned long address, pte_t *ptep,
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pte_t entry, int dirty);
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#endif
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#ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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extern int pmdp_set_access_flags(struct vm_area_struct *vma,
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unsigned long address, pmd_t *pmdp,
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pmd_t entry, int dirty);
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extern int pudp_set_access_flags(struct vm_area_struct *vma,
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unsigned long address, pud_t *pudp,
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pud_t entry, int dirty);
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#else
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static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
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unsigned long address, pmd_t *pmdp,
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pmd_t entry, int dirty)
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{
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BUILD_BUG();
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return 0;
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}
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static inline int pudp_set_access_flags(struct vm_area_struct *vma,
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unsigned long address, pud_t *pudp,
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pud_t entry, int dirty)
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{
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BUILD_BUG();
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return 0;
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}
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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#endif
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#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
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static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
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unsigned long address,
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pte_t *ptep)
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{
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pte_t pte = *ptep;
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int r = 1;
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if (!pte_young(pte))
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r = 0;
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else
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set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte));
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return r;
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}
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#endif
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#ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
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unsigned long address,
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pmd_t *pmdp)
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{
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pmd_t pmd = *pmdp;
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int r = 1;
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if (!pmd_young(pmd))
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r = 0;
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else
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set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd));
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return r;
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}
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#else
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static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
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unsigned long address,
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pmd_t *pmdp)
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{
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BUILD_BUG();
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return 0;
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}
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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#endif
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#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
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int ptep_clear_flush_young(struct vm_area_struct *vma,
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unsigned long address, pte_t *ptep);
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#endif
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#ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
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#ifdef CONFIG_TRANSPARENT_HUGEPAGE
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extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
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unsigned long address, pmd_t *pmdp);
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#else
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/*
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* Despite relevant to THP only, this API is called from generic rmap code
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* under PageTransHuge(), hence needs a dummy implementation for !THP
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*/
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static inline int pmdp_clear_flush_young(struct vm_area_struct *vma,
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unsigned long address, pmd_t *pmdp)
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{
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BUILD_BUG();
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return 0;
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}
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#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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#endif
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#ifndef __HAVE_ARCH_PTEP_CLEAR
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static inline void ptep_clear(struct mm_struct *mm, unsigned long addr,
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pte_t *ptep)
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{
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pte_clear(mm, addr, ptep);
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}
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#endif
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#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
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static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
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unsigned long address,
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pte_t *ptep)
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{
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pte_t pte = *ptep;
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pte_clear(mm, address, ptep);
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return pte;
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}
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#endif
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#ifndef __HAVE_ARCH_PTEP_GET
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static inline pte_t ptep_get(pte_t *ptep)
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{
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return READ_ONCE(*ptep);
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}
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#endif
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#ifdef CONFIG_GUP_GET_PTE_LOW_HIGH
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/*
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* WARNING: only to be used in the get_user_pages_fast() implementation.
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*
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* With get_user_pages_fast(), we walk down the pagetables without taking any
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* locks. For this we would like to load the pointers atomically, but sometimes
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* that is not possible (e.g. without expensive cmpxchg8b on x86_32 PAE). What
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* we do have is the guarantee that a PTE will only either go from not present
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* to present, or present to not present or both -- it will not switch to a
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* completely different present page without a TLB flush in between; something
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* that we are blocking by holding interrupts off.
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*
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* Setting ptes from not present to present goes:
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*
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* ptep->pte_high = h;
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* smp_wmb();
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* ptep->pte_low = l;
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*
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* And present to not present goes:
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*
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* ptep->pte_low = 0;
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* smp_wmb();
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* ptep->pte_high = 0;
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*
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* We must ensure here that the load of pte_low sees 'l' IFF pte_high sees 'h'.
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* We load pte_high *after* loading pte_low, which ensures we don't see an older
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* value of pte_high. *Then* we recheck pte_low, which ensures that we haven't
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* picked up a changed pte high. We might have gotten rubbish values from
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* pte_low and pte_high, but we are guaranteed that pte_low will not have the
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* present bit set *unless* it is 'l'. Because get_user_pages_fast() only
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* operates on present ptes we're safe.
|
|
*/
|
|
static inline pte_t ptep_get_lockless(pte_t *ptep)
|
|
{
|
|
pte_t pte;
|
|
|
|
do {
|
|
pte.pte_low = ptep->pte_low;
|
|
smp_rmb();
|
|
pte.pte_high = ptep->pte_high;
|
|
smp_rmb();
|
|
} while (unlikely(pte.pte_low != ptep->pte_low));
|
|
|
|
return pte;
|
|
}
|
|
#else /* CONFIG_GUP_GET_PTE_LOW_HIGH */
|
|
/*
|
|
* We require that the PTE can be read atomically.
|
|
*/
|
|
static inline pte_t ptep_get_lockless(pte_t *ptep)
|
|
{
|
|
return ptep_get(ptep);
|
|
}
|
|
#endif /* CONFIG_GUP_GET_PTE_LOW_HIGH */
|
|
|
|
#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 vm_area_struct *vma,
|
|
unsigned long address, pmd_t *pmdp,
|
|
int full)
|
|
{
|
|
return pmdp_huge_get_and_clear(vma->vm_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
|
|
|
|
|
|
/*
|
|
* If two threads concurrently fault at the same page, the thread that
|
|
* won the race updates the PTE and its local TLB/Cache. The other thread
|
|
* gives up, simply does nothing, and continues; on architectures where
|
|
* software can update TLB, local TLB can be updated here to avoid next page
|
|
* fault. This function updates TLB only, do nothing with cache or others.
|
|
* It is the difference with function update_mmu_cache.
|
|
*/
|
|
#ifndef __HAVE_ARCH_UPDATE_MMU_TLB
|
|
static inline void update_mmu_tlb(struct vm_area_struct *vma,
|
|
unsigned long address, pte_t *ptep)
|
|
{
|
|
}
|
|
#define __HAVE_ARCH_UPDATE_MMU_TLB
|
|
#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
|
|
|
|
/*
|
|
* On some architectures hardware does not set page access bit when accessing
|
|
* memory page, it is responsibility of software setting this bit. It brings
|
|
* out extra page fault penalty to track page access bit. For optimization page
|
|
* access bit can be set during all page fault flow on these arches.
|
|
* To be differentiate with macro pte_mkyoung, this macro is used on platforms
|
|
* where software maintains page access bit.
|
|
*/
|
|
#ifndef pte_sw_mkyoung
|
|
static inline pte_t pte_sw_mkyoung(pte_t pte)
|
|
{
|
|
return pte;
|
|
}
|
|
#define pte_sw_mkyoung pte_sw_mkyoung
|
|
#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
|
|
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
/*
|
|
* This is an implementation of pmdp_establish() that is only suitable for an
|
|
* architecture that doesn't have hardware dirty/accessed bits. In this case we
|
|
* can't race with CPU which sets these bits and non-atomic approach is fine.
|
|
*/
|
|
static inline pmd_t generic_pmdp_establish(struct vm_area_struct *vma,
|
|
unsigned long address, pmd_t *pmdp, pmd_t pmd)
|
|
{
|
|
pmd_t old_pmd = *pmdp;
|
|
set_pmd_at(vma->vm_mm, address, pmdp, pmd);
|
|
return old_pmd;
|
|
}
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_PMDP_INVALIDATE
|
|
extern pmd_t pmdp_invalidate(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
|
|
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);
|
|
}
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_P4D_SAME
|
|
static inline int p4d_same(p4d_t p4d_a, p4d_t p4d_b)
|
|
{
|
|
return p4d_val(p4d_a) == p4d_val(p4d_b);
|
|
}
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_PGD_SAME
|
|
static inline int pgd_same(pgd_t pgd_a, pgd_t pgd_b)
|
|
{
|
|
return pgd_val(pgd_a) == pgd_val(pgd_b);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Use set_p*_safe(), and elide TLB flushing, when confident that *no*
|
|
* TLB flush will be required as a result of the "set". For example, use
|
|
* in scenarios where it is known ahead of time that the routine is
|
|
* setting non-present entries, or re-setting an existing entry to the
|
|
* same value. Otherwise, use the typical "set" helpers and flush the
|
|
* TLB.
|
|
*/
|
|
#define set_pte_safe(ptep, pte) \
|
|
({ \
|
|
WARN_ON_ONCE(pte_present(*ptep) && !pte_same(*ptep, pte)); \
|
|
set_pte(ptep, pte); \
|
|
})
|
|
|
|
#define set_pmd_safe(pmdp, pmd) \
|
|
({ \
|
|
WARN_ON_ONCE(pmd_present(*pmdp) && !pmd_same(*pmdp, pmd)); \
|
|
set_pmd(pmdp, pmd); \
|
|
})
|
|
|
|
#define set_pud_safe(pudp, pud) \
|
|
({ \
|
|
WARN_ON_ONCE(pud_present(*pudp) && !pud_same(*pudp, pud)); \
|
|
set_pud(pudp, pud); \
|
|
})
|
|
|
|
#define set_p4d_safe(p4dp, p4d) \
|
|
({ \
|
|
WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \
|
|
set_p4d(p4dp, p4d); \
|
|
})
|
|
|
|
#define set_pgd_safe(pgdp, pgd) \
|
|
({ \
|
|
WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \
|
|
set_pgd(pgdp, pgd); \
|
|
})
|
|
|
|
#ifndef __HAVE_ARCH_DO_SWAP_PAGE
|
|
/*
|
|
* Some architectures support metadata associated with a page. When a
|
|
* page is being swapped out, this metadata must be saved so it can be
|
|
* restored when the page is swapped back in. SPARC M7 and newer
|
|
* processors support an ADI (Application Data Integrity) tag for the
|
|
* page as metadata for the page. arch_do_swap_page() can restore this
|
|
* metadata when a page is swapped back in.
|
|
*/
|
|
static inline void arch_do_swap_page(struct mm_struct *mm,
|
|
struct vm_area_struct *vma,
|
|
unsigned long addr,
|
|
pte_t pte, pte_t oldpte)
|
|
{
|
|
|
|
}
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_UNMAP_ONE
|
|
/*
|
|
* Some architectures support metadata associated with a page. When a
|
|
* page is being swapped out, this metadata must be saved so it can be
|
|
* restored when the page is swapped back in. SPARC M7 and newer
|
|
* processors support an ADI (Application Data Integrity) tag for the
|
|
* page as metadata for the page. arch_unmap_one() can save this
|
|
* metadata on a swap-out of a page.
|
|
*/
|
|
static inline int arch_unmap_one(struct mm_struct *mm,
|
|
struct vm_area_struct *vma,
|
|
unsigned long addr,
|
|
pte_t orig_pte)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Allow architectures to preserve additional metadata associated with
|
|
* swapped-out pages. The corresponding __HAVE_ARCH_SWAP_* macros and function
|
|
* prototypes must be defined in the arch-specific asm/pgtable.h file.
|
|
*/
|
|
#ifndef __HAVE_ARCH_PREPARE_TO_SWAP
|
|
static inline int arch_prepare_to_swap(struct page *page)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_SWAP_INVALIDATE
|
|
static inline void arch_swap_invalidate_page(int type, pgoff_t offset)
|
|
{
|
|
}
|
|
|
|
static inline void arch_swap_invalidate_area(int type)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
#ifndef __HAVE_ARCH_SWAP_RESTORE
|
|
static inline void arch_swap_restore(swp_entry_t entry, struct page *page)
|
|
{
|
|
}
|
|
#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
|
|
|
|
/*
|
|
* 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 *);
|
|
|
|
#ifndef __PAGETABLE_P4D_FOLDED
|
|
void p4d_clear_bad(p4d_t *);
|
|
#else
|
|
#define p4d_clear_bad(p4d) do { } while (0)
|
|
#endif
|
|
|
|
#ifndef __PAGETABLE_PUD_FOLDED
|
|
void pud_clear_bad(pud_t *);
|
|
#else
|
|
#define pud_clear_bad(p4d) do { } while (0)
|
|
#endif
|
|
|
|
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 vm_area_struct *vma,
|
|
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(vma->vm_mm, addr, ptep);
|
|
}
|
|
|
|
static inline void __ptep_modify_prot_commit(struct vm_area_struct *vma,
|
|
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(vma->vm_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 transaction.
|
|
*
|
|
* 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 vm_area_struct *vma,
|
|
unsigned long addr,
|
|
pte_t *ptep)
|
|
{
|
|
return __ptep_modify_prot_start(vma, 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 vm_area_struct *vma,
|
|
unsigned long addr,
|
|
pte_t *ptep, pte_t old_pte, pte_t pte)
|
|
{
|
|
__ptep_modify_prot_commit(vma, 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 even if CONFIG_MMU is not defined.
|
|
*/
|
|
|
|
#ifndef pgprot_nx
|
|
#define pgprot_nx(prot) (prot)
|
|
#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_mhp
|
|
#define pgprot_mhp(prot) (prot)
|
|
#endif
|
|
|
|
#ifdef CONFIG_MMU
|
|
#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
|
|
#endif /* CONFIG_MMU */
|
|
|
|
#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
|
|
|
|
/*
|
|
* When replacing an anonymous page by a real (!non) swap entry, we clear
|
|
* PG_anon_exclusive from the page and instead remember whether the flag was
|
|
* set in the swp pte. During fork(), we have to mark the entry as !exclusive
|
|
* (possibly shared). On swapin, we use that information to restore
|
|
* PG_anon_exclusive, which is very helpful in cases where we might have
|
|
* additional (e.g., FOLL_GET) references on a page and wouldn't be able to
|
|
* detect exclusivity.
|
|
*
|
|
* These functions don't apply to non-swap entries (e.g., migration, hwpoison,
|
|
* ...).
|
|
*/
|
|
#ifndef __HAVE_ARCH_PTE_SWP_EXCLUSIVE
|
|
static inline pte_t pte_swp_mkexclusive(pte_t pte)
|
|
{
|
|
return pte;
|
|
}
|
|
|
|
static inline int pte_swp_exclusive(pte_t pte)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
static inline pte_t pte_swp_clear_exclusive(pte_t pte)
|
|
{
|
|
return pte;
|
|
}
|
|
#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,
|
|
* vmf_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 vmf_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 CONFIG_MMU
|
|
#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
|
|
#else
|
|
static inline int is_zero_pfn(unsigned long pfn)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline unsigned long my_zero_pfn(unsigned long addr)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_MMU */
|
|
|
|
#ifdef CONFIG_MMU
|
|
|
|
#ifndef CONFIG_TRANSPARENT_HUGEPAGE
|
|
static inline int pmd_trans_huge(pmd_t pmd)
|
|
{
|
|
return 0;
|
|
}
|
|
#ifndef pmd_write
|
|
static inline int pmd_write(pmd_t pmd)
|
|
{
|
|
BUG();
|
|
return 0;
|
|
}
|
|
#endif /* pmd_write */
|
|
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
|
|
|
|
#ifndef pud_write
|
|
static inline int pud_write(pud_t pud)
|
|
{
|
|
BUG();
|
|
return 0;
|
|
}
|
|
#endif /* pud_write */
|
|
|
|
#if !defined(CONFIG_ARCH_HAS_PTE_DEVMAP) || !defined(CONFIG_TRANSPARENT_HUGEPAGE)
|
|
static inline int pmd_devmap(pmd_t pmd)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int pud_devmap(pud_t pud)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int pgd_devmap(pgd_t pgd)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#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
|
|
|
|
/* See pmd_none_or_trans_huge_or_clear_bad for discussion. */
|
|
static inline int pud_none_or_trans_huge_or_dev_or_clear_bad(pud_t *pud)
|
|
{
|
|
pud_t pudval = READ_ONCE(*pud);
|
|
|
|
if (pud_none(pudval) || pud_trans_huge(pudval) || pud_devmap(pudval))
|
|
return 1;
|
|
if (unlikely(pud_bad(pudval))) {
|
|
pud_clear_bad(pud);
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* See pmd_trans_unstable for discussion. */
|
|
static inline int pud_trans_unstable(pud_t *pud)
|
|
{
|
|
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && \
|
|
defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)
|
|
return pud_none_or_trans_huge_or_dev_or_clear_bad(pud);
|
|
#else
|
|
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_lock held 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_lock 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_lock 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 resolve 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 preserved 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_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
|
|
}
|
|
|
|
/*
|
|
* the ordering of these checks is important for pmds with _page_devmap set.
|
|
* if we check pmd_trans_unstable() first we will trip the bad_pmd() check
|
|
* inside of pmd_none_or_trans_huge_or_clear_bad(). this will end up correctly
|
|
* returning 1 but not before it spams dmesg with the pmd_clear_bad() output.
|
|
*/
|
|
static inline int pmd_devmap_trans_unstable(pmd_t *pmd)
|
|
{
|
|
return pmd_devmap(*pmd) || pmd_trans_unstable(pmd);
|
|
}
|
|
|
|
#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 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);
|
|
int p4d_free_pud_page(p4d_t *p4d, unsigned long addr);
|
|
int pud_free_pmd_page(pud_t *pud, unsigned long addr);
|
|
int pmd_free_pte_page(pmd_t *pmd, unsigned long addr);
|
|
#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;
|
|
}
|
|
static inline int p4d_free_pud_page(p4d_t *p4d, unsigned long addr)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int pud_free_pmd_page(pud_t *pud, unsigned long addr)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
|
|
{
|
|
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 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 desirable.
|
|
* 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);
|
|
|
|
#ifndef CONFIG_X86_ESPFIX64
|
|
static inline void init_espfix_bsp(void) { }
|
|
#endif
|
|
|
|
extern void __init pgtable_cache_init(void);
|
|
|
|
#ifndef __HAVE_ARCH_PFN_MODIFY_ALLOWED
|
|
static inline bool pfn_modify_allowed(unsigned long pfn, pgprot_t prot)
|
|
{
|
|
return true;
|
|
}
|
|
|
|
static inline bool arch_has_pfn_modify_check(void)
|
|
{
|
|
return false;
|
|
}
|
|
#endif /* !_HAVE_ARCH_PFN_MODIFY_ALLOWED */
|
|
|
|
/*
|
|
* Architecture PAGE_KERNEL_* fallbacks
|
|
*
|
|
* Some architectures don't define certain PAGE_KERNEL_* flags. This is either
|
|
* because they really don't support them, or the port needs to be updated to
|
|
* reflect the required functionality. Below are a set of relatively safe
|
|
* fallbacks, as best effort, which we can count on in lieu of the architectures
|
|
* not defining them on their own yet.
|
|
*/
|
|
|
|
#ifndef PAGE_KERNEL_RO
|
|
# define PAGE_KERNEL_RO PAGE_KERNEL
|
|
#endif
|
|
|
|
#ifndef PAGE_KERNEL_EXEC
|
|
# define PAGE_KERNEL_EXEC PAGE_KERNEL
|
|
#endif
|
|
|
|
/*
|
|
* Page Table Modification bits for pgtbl_mod_mask.
|
|
*
|
|
* These are used by the p?d_alloc_track*() set of functions an in the generic
|
|
* vmalloc/ioremap code to track at which page-table levels entries have been
|
|
* modified. Based on that the code can better decide when vmalloc and ioremap
|
|
* mapping changes need to be synchronized to other page-tables in the system.
|
|
*/
|
|
#define __PGTBL_PGD_MODIFIED 0
|
|
#define __PGTBL_P4D_MODIFIED 1
|
|
#define __PGTBL_PUD_MODIFIED 2
|
|
#define __PGTBL_PMD_MODIFIED 3
|
|
#define __PGTBL_PTE_MODIFIED 4
|
|
|
|
#define PGTBL_PGD_MODIFIED BIT(__PGTBL_PGD_MODIFIED)
|
|
#define PGTBL_P4D_MODIFIED BIT(__PGTBL_P4D_MODIFIED)
|
|
#define PGTBL_PUD_MODIFIED BIT(__PGTBL_PUD_MODIFIED)
|
|
#define PGTBL_PMD_MODIFIED BIT(__PGTBL_PMD_MODIFIED)
|
|
#define PGTBL_PTE_MODIFIED BIT(__PGTBL_PTE_MODIFIED)
|
|
|
|
/* Page-Table Modification Mask */
|
|
typedef unsigned int pgtbl_mod_mask;
|
|
|
|
#endif /* !__ASSEMBLY__ */
|
|
|
|
#if !defined(MAX_POSSIBLE_PHYSMEM_BITS) && !defined(CONFIG_64BIT)
|
|
#ifdef CONFIG_PHYS_ADDR_T_64BIT
|
|
/*
|
|
* ZSMALLOC needs to know the highest PFN on 32-bit architectures
|
|
* with physical address space extension, but falls back to
|
|
* BITS_PER_LONG otherwise.
|
|
*/
|
|
#error Missing MAX_POSSIBLE_PHYSMEM_BITS definition
|
|
#else
|
|
#define MAX_POSSIBLE_PHYSMEM_BITS 32
|
|
#endif
|
|
#endif
|
|
|
|
#ifndef has_transparent_hugepage
|
|
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
|
|
#define has_transparent_hugepage() 1
|
|
#else
|
|
#define has_transparent_hugepage() 0
|
|
#endif
|
|
#endif
|
|
|
|
/*
|
|
* On some architectures it depends on the mm if the p4d/pud or pmd
|
|
* layer of the page table hierarchy is folded or not.
|
|
*/
|
|
#ifndef mm_p4d_folded
|
|
#define mm_p4d_folded(mm) __is_defined(__PAGETABLE_P4D_FOLDED)
|
|
#endif
|
|
|
|
#ifndef mm_pud_folded
|
|
#define mm_pud_folded(mm) __is_defined(__PAGETABLE_PUD_FOLDED)
|
|
#endif
|
|
|
|
#ifndef mm_pmd_folded
|
|
#define mm_pmd_folded(mm) __is_defined(__PAGETABLE_PMD_FOLDED)
|
|
#endif
|
|
|
|
#ifndef p4d_offset_lockless
|
|
#define p4d_offset_lockless(pgdp, pgd, address) p4d_offset(&(pgd), address)
|
|
#endif
|
|
#ifndef pud_offset_lockless
|
|
#define pud_offset_lockless(p4dp, p4d, address) pud_offset(&(p4d), address)
|
|
#endif
|
|
#ifndef pmd_offset_lockless
|
|
#define pmd_offset_lockless(pudp, pud, address) pmd_offset(&(pud), address)
|
|
#endif
|
|
|
|
/*
|
|
* p?d_leaf() - true if this entry is a final mapping to a physical address.
|
|
* This differs from p?d_huge() by the fact that they are always available (if
|
|
* the architecture supports large pages at the appropriate level) even
|
|
* if CONFIG_HUGETLB_PAGE is not defined.
|
|
* Only meaningful when called on a valid entry.
|
|
*/
|
|
#ifndef pgd_leaf
|
|
#define pgd_leaf(x) 0
|
|
#endif
|
|
#ifndef p4d_leaf
|
|
#define p4d_leaf(x) 0
|
|
#endif
|
|
#ifndef pud_leaf
|
|
#define pud_leaf(x) 0
|
|
#endif
|
|
#ifndef pmd_leaf
|
|
#define pmd_leaf(x) 0
|
|
#endif
|
|
|
|
#ifndef pgd_leaf_size
|
|
#define pgd_leaf_size(x) (1ULL << PGDIR_SHIFT)
|
|
#endif
|
|
#ifndef p4d_leaf_size
|
|
#define p4d_leaf_size(x) P4D_SIZE
|
|
#endif
|
|
#ifndef pud_leaf_size
|
|
#define pud_leaf_size(x) PUD_SIZE
|
|
#endif
|
|
#ifndef pmd_leaf_size
|
|
#define pmd_leaf_size(x) PMD_SIZE
|
|
#endif
|
|
#ifndef pte_leaf_size
|
|
#define pte_leaf_size(x) PAGE_SIZE
|
|
#endif
|
|
|
|
/*
|
|
* Some architectures have MMUs that are configurable or selectable at boot
|
|
* time. These lead to variable PTRS_PER_x. For statically allocated arrays it
|
|
* helps to have a static maximum value.
|
|
*/
|
|
|
|
#ifndef MAX_PTRS_PER_PTE
|
|
#define MAX_PTRS_PER_PTE PTRS_PER_PTE
|
|
#endif
|
|
|
|
#ifndef MAX_PTRS_PER_PMD
|
|
#define MAX_PTRS_PER_PMD PTRS_PER_PMD
|
|
#endif
|
|
|
|
#ifndef MAX_PTRS_PER_PUD
|
|
#define MAX_PTRS_PER_PUD PTRS_PER_PUD
|
|
#endif
|
|
|
|
#ifndef MAX_PTRS_PER_P4D
|
|
#define MAX_PTRS_PER_P4D PTRS_PER_P4D
|
|
#endif
|
|
|
|
#endif /* _LINUX_PGTABLE_H */
|