mm: convert do_set_pte() to set_pte_range()

set_pte_range() allows to setup page table entries for a specific
range.  It takes advantage of batched rmap update for large folio.
It now takes care of calling update_mmu_cache_range().

Link: https://lkml.kernel.org/r/20230802151406.3735276-37-willy@infradead.org
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst
index ed14891..211a030 100644 (file)
--- a/Documentation/filesystems/locking.rst
+++ b/Documentation/filesystems/locking.rst
@@ -661,7 +661,7 @@ locked. The VM will unlock the page.
 Filesystem should find and map pages associated with offsets from "start_pgoff"
 till "end_pgoff". ->map_pages() is called with the RCU lock held and must
 not block.  If it's not possible to reach a page without blocking,
-filesystem should skip it. Filesystem should use do_set_pte() to setup
+filesystem should skip it. Filesystem should use set_pte_range() to setup
 page table entry. Pointer to entry associated with the page is passed in
 "pte" field in vm_fault structure. Pointers to entries for other offsets
 should be calculated relative to "pte".

diff --git a/include/linux/mm.h b/include/linux/mm.h
index c1db400..ddb9596 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1322,7 +1322,8 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
 }
 
 vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page);
-void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr);
+void set_pte_range(struct vm_fault *vmf, struct folio *folio,
+               struct page *page, unsigned int nr, unsigned long addr);
 
 vm_fault_t finish_fault(struct vm_fault *vmf);
 vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf);

diff --git a/mm/filemap.c b/mm/filemap.c
index bdc1e0b..c06e9d3 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3501,8 +3501,7 @@ static vm_fault_t filemap_map_folio_range(struct vm_fault *vmf,
                        ret = VM_FAULT_NOPAGE;
 
                ref_count++;
-               do_set_pte(vmf, page, addr);
-               update_mmu_cache(vma, addr, vmf->pte);
+               set_pte_range(vmf, folio, page, 1, addr);
        } while (vmf->pte++, page++, addr += PAGE_SIZE, ++count < nr_pages);
 
        /* Restore the vmf->pte */

diff --git a/mm/memory.c b/mm/memory.c
index fbb7f06..12b385e 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4330,15 +4330,24 @@ vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page)
 }
 #endif
 
-void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr)
+/**
+ * set_pte_range - Set a range of PTEs to point to pages in a folio.
+ * @vmf: Fault decription.
+ * @folio: The folio that contains @page.
+ * @page: The first page to create a PTE for.
+ * @nr: The number of PTEs to create.
+ * @addr: The first address to create a PTE for.
+ */
+void set_pte_range(struct vm_fault *vmf, struct folio *folio,
+               struct page *page, unsigned int nr, unsigned long addr)
 {
        struct vm_area_struct *vma = vmf->vma;
        bool uffd_wp = vmf_orig_pte_uffd_wp(vmf);
        bool write = vmf->flags & FAULT_FLAG_WRITE;
-       bool prefault = vmf->address != addr;
+       bool prefault = in_range(vmf->address, addr, nr * PAGE_SIZE);
        pte_t entry;
 
-       flush_icache_page(vma, page);
+       flush_icache_pages(vma, page, nr);
        entry = mk_pte(page, vma->vm_page_prot);
 
        if (prefault && arch_wants_old_prefaulted_pte())
@@ -4352,14 +4361,18 @@ void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr)
                entry = pte_mkuffd_wp(entry);
        /* copy-on-write page */
        if (write && !(vma->vm_flags & VM_SHARED)) {
-               inc_mm_counter(vma->vm_mm, MM_ANONPAGES);
-               page_add_new_anon_rmap(page, vma, addr);
-               lru_cache_add_inactive_or_unevictable(page, vma);
+               add_mm_counter(vma->vm_mm, MM_ANONPAGES, nr);
+               VM_BUG_ON_FOLIO(nr != 1, folio);
+               folio_add_new_anon_rmap(folio, vma, addr);
+               folio_add_lru_vma(folio, vma);
        } else {
-               inc_mm_counter(vma->vm_mm, mm_counter_file(page));
-               page_add_file_rmap(page, vma, false);
+               add_mm_counter(vma->vm_mm, mm_counter_file(page), nr);
+               folio_add_file_rmap_range(folio, page, nr, vma, false);
        }
-       set_pte_at(vma->vm_mm, addr, vmf->pte, entry);
+       set_ptes(vma->vm_mm, addr, vmf->pte, entry, nr);
+
+       /* no need to invalidate: a not-present page won't be cached */
+       update_mmu_cache_range(vmf, vma, addr, vmf->pte, nr);
 }
 
 static bool vmf_pte_changed(struct vm_fault *vmf)
@@ -4427,11 +4440,9 @@ vm_fault_t finish_fault(struct vm_fault *vmf)
 
        /* Re-check under ptl */
        if (likely(!vmf_pte_changed(vmf))) {
-               do_set_pte(vmf, page, vmf->address);
-
-               /* no need to invalidate: a not-present page won't be cached */
-               update_mmu_cache(vma, vmf->address, vmf->pte);
+               struct folio *folio = page_folio(page);
 
+               set_pte_range(vmf, folio, page, 1, vmf->address);
                ret = 0;
        } else {
                update_mmu_tlb(vma, vmf->address, vmf->pte);