The patch titled
Subject: mm: add default definition of set_ptes()
has been added to the -mm mm-unstable branch. Its filename is
mm-add-default-definition-of-set_ptes.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-add-default-definition-of-set_ptes.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: mm: add default definition of set_ptes()
Date: Wed, 2 Aug 2023 16:13:34 +0100
Most architectures can just define set_pte() and PFN_PTE_SHIFT to use this
definition. It's also a handy spot to document the guarantees provided by
the MM.
Link: https://lkml.kernel.org/r/20230802151406.3735276-7-willy@xxxxxxxxxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Suggested-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Reviewed-by: Mike Rapoport (IBM) <rppt@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/pgtable.h | 81 ++++++++++++++++++++++++++++----------
1 file changed, 60 insertions(+), 21 deletions(-)
--- a/include/linux/pgtable.h~mm-add-default-definition-of-set_ptes
+++ a/include/linux/pgtable.h
@@ -182,6 +182,66 @@ static inline int pmd_young(pmd_t pmd)
}
#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
+
+#ifndef set_ptes
+#ifdef PFN_PTE_SHIFT
+/**
+ * set_ptes - Map consecutive pages to a contiguous range of addresses.
+ * @mm: Address space to map the pages into.
+ * @addr: Address to map the first page at.
+ * @ptep: Page table pointer for the first entry.
+ * @pte: Page table entry for the first page.
+ * @nr: Number of pages to map.
+ *
+ * May be overridden by the architecture, or the architecture can define
+ * set_pte() and PFN_PTE_SHIFT.
+ *
+ * Context: The caller holds the page table lock. The pages all belong
+ * to the same folio. The PTEs are all in the same PMD.
+ */
+static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte, unsigned int nr)
+{
+ page_table_check_ptes_set(mm, ptep, pte, nr);
+
+ arch_enter_lazy_mmu_mode();
+ for (;;) {
+ set_pte(ptep, pte);
+ if (--nr == 0)
+ break;
+ ptep++;
+ pte = __pte(pte_val(pte) + (1UL << PFN_PTE_SHIFT));
+ }
+ arch_leave_lazy_mmu_mode();
+}
+#ifndef set_pte_at
+#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
+#endif
+#endif
+#else
+#define set_pte_at(mm, addr, ptep, pte) set_ptes(mm, addr, ptep, pte, 1)
+#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,
@@ -1132,27 +1192,6 @@ static inline pgprot_t pgprot_modify(pgp
#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
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-drop-per-vma-lock-when-returning-vm_fault_retry-or-vm_fault_completed-fix.patch
rmap-pass-the-folio-to-__page_check_anon_rmap.patch
highmem-add-memcpy_to_folio-and-memcpy_from_folio.patch
affs-convert-affs_symlink_read_folio-to-use-the-folio.patch
affs-convert-data-read-and-write-to-use-folios.patch
migrate-use-folio_set_bh-instead-of-set_bh_page.patch
ntfs3-convert-ntfs_get_block_vbo-to-use-a-folio.patch
jbd2-use-a-folio-in-jbd2_journal_write_metadata_buffer.patch
buffer-remove-set_bh_page.patch
zswap-make-zswap_store-take-a-folio.patch
memcg-convert-get_obj_cgroup_from_page-to-get_obj_cgroup_from_folio.patch
swap-remove-some-calls-to-compound_head-in-swap_readpage.patch
zswap-make-zswap_load-take-a-folio.patch
mm-remove-config_per_vma_lock-ifdefs.patch
mm-allow-per-vma-locks-on-file-backed-vmas.patch
mm-move-fault_flag_vma_lock-check-from-handle_mm_fault.patch
mm-handle-pud-faults-under-the-vma-lock.patch
mm-handle-some-pmd-faults-under-the-vma-lock.patch
mm-move-fault_flag_vma_lock-check-down-in-handle_pte_fault.patch
mm-move-fault_flag_vma_lock-check-down-from-do_fault.patch
mm-run-the-fault-around-code-under-the-vma-lock.patch
mm-handle-swap-and-numa-pte-faults-under-the-vma-lock.patch
mm-handle-faults-that-merely-update-the-accessed-bit-under-the-vma-lock.patch
mm-handle-faults-that-merely-update-the-accessed-bit-under-the-vma-lock-fix.patch
mm-improve-the-comment-in-isolate_migratepages_block.patch
minmax-add-in_range-macro.patch
mm-convert-page_table_check_pte_set-to-page_table_check_ptes_set.patch
mm-add-generic-flush_icache_pages-and-documentation.patch
mm-add-folio_flush_mapping.patch
mm-remove-arch_implements_flush_dcache_folio.patch
mm-add-default-definition-of-set_ptes.patch
alpha-implement-the-new-page-table-range-api.patch
arc-implement-the-new-page-table-range-api.patch
arm-implement-the-new-page-table-range-api.patch
arm64-implement-the-new-page-table-range-api.patch
csky-implement-the-new-page-table-range-api.patch
hexagon-implement-the-new-page-table-range-api.patch
ia64-implement-the-new-page-table-range-api.patch
loongarch-implement-the-new-page-table-range-api.patch
m68k-implement-the-new-page-table-range-api.patch
microblaze-implement-the-new-page-table-range-api.patch
mips-implement-the-new-page-table-range-api.patch
nios2-implement-the-new-page-table-range-api.patch
openrisc-implement-the-new-page-table-range-api.patch
parisc-implement-the-new-page-table-range-api.patch
powerpc-implement-the-new-page-table-range-api.patch
riscv-implement-the-new-page-table-range-api.patch
s390-implement-the-new-page-table-range-api.patch
sh-implement-the-new-page-table-range-api.patch
sparc32-implement-the-new-page-table-range-api.patch
sparc64-implement-the-new-page-table-range-api.patch
um-implement-the-new-page-table-range-api.patch
x86-implement-the-new-page-table-range-api.patch
xtensa-implement-the-new-page-table-range-api.patch
mm-remove-page_mapping_file.patch
mm-rationalise-flush_icache_pages-and-flush_icache_page.patch
mm-tidy-up-set_ptes-definition.patch
mm-use-flush_icache_pages-in-do_set_pmd.patch
mm-call-update_mmu_cache_range-in-more-page-fault-handling-paths.patch
