1 files changed, 52 insertions, 9 deletions

diff --git a/mm/mmu_gather.c b/mm/mmu_gather.c
index 6540c99c6758..d175c0f1e2c8 100644
--- a/mm/mmu_gather.c
+++ b/mm/mmu_gather.c
@@ -50,12 +50,21 @@ static bool tlb_next_batch(struct mmu_gather *tlb)
 #ifdef CONFIG_SMP
 static void tlb_flush_rmap_batch(struct mmu_gather_batch *batch, struct vm_area_struct *vma)
 {
+	struct encoded_page **pages = batch->encoded_pages;
+
 	for (int i = 0; i < batch->nr; i++) {
-		struct encoded_page *enc = batch->encoded_pages[i];
+		struct encoded_page *enc = pages[i];
 
 		if (encoded_page_flags(enc) & ENCODED_PAGE_BIT_DELAY_RMAP) {
 			struct page *page = encoded_page_ptr(enc);
-			folio_remove_rmap_pte(page_folio(page), page, vma);
+			unsigned int nr_pages = 1;
+
+			if (unlikely(encoded_page_flags(enc) &
+				     ENCODED_PAGE_BIT_NR_PAGES_NEXT))
+				nr_pages = encoded_nr_pages(pages[++i]);
+
+			folio_remove_rmap_ptes(page_folio(page), page, nr_pages,
+					       vma);
 		}
 	}
 }
@@ -89,18 +98,26 @@ static void tlb_batch_pages_flush(struct mmu_gather *tlb)
 	for (batch = &tlb->local; batch && batch->nr; batch = batch->next) {
 		struct encoded_page **pages = batch->encoded_pages;
 
-		do {
+		while (batch->nr) {
 			/*
 			 * limit free batch count when PAGE_SIZE > 4K
 			 */
 			unsigned int nr = min(512U, batch->nr);
 
+			/*
+			 * Make sure we cover page + nr_pages, and don't leave
+			 * nr_pages behind when capping the number of entries.
+			 */
+			if (unlikely(encoded_page_flags(pages[nr - 1]) &
+				     ENCODED_PAGE_BIT_NR_PAGES_NEXT))
+				nr++;
+
 			free_pages_and_swap_cache(pages, nr);
 			pages += nr;
 			batch->nr -= nr;
 
 			cond_resched();
-		} while (batch->nr);
+		}
 	}
 	tlb->active = &tlb->local;
 }
@@ -116,8 +133,9 @@ static void tlb_batch_list_free(struct mmu_gather *tlb)
 	tlb->local.next = NULL;
 }
 
-bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page,
-		bool delay_rmap, int page_size)
+static bool __tlb_remove_folio_pages_size(struct mmu_gather *tlb,
+		struct page *page, unsigned int nr_pages, bool delay_rmap,
+		int page_size)
 {
 	int flags = delay_rmap ? ENCODED_PAGE_BIT_DELAY_RMAP : 0;
 	struct mmu_gather_batch *batch;
@@ -126,6 +144,8 @@ bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page,
 
 #ifdef CONFIG_MMU_GATHER_PAGE_SIZE
 	VM_WARN_ON(tlb->page_size != page_size);
+	VM_WARN_ON_ONCE(nr_pages != 1 && page_size != PAGE_SIZE);
+	VM_WARN_ON_ONCE(page_folio(page) != page_folio(page + nr_pages - 1));
 #endif
 
 	batch = tlb->active;
@@ -133,17 +153,40 @@ bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page,
 	 * Add the page and check if we are full. If so
 	 * force a flush.
 	 */
-	batch->encoded_pages[batch->nr++] = encode_page(page, flags);
-	if (batch->nr == batch->max) {
+	if (likely(nr_pages == 1)) {
+		batch->encoded_pages[batch->nr++] = encode_page(page, flags);
+	} else {
+		flags |= ENCODED_PAGE_BIT_NR_PAGES_NEXT;
+		batch->encoded_pages[batch->nr++] = encode_page(page, flags);
+		batch->encoded_pages[batch->nr++] = encode_nr_pages(nr_pages);
+	}
+	/*
+	 * Make sure that we can always add another "page" + "nr_pages",
+	 * requiring two entries instead of only a single one.
+	 */
+	if (batch->nr >= batch->max - 1) {
 		if (!tlb_next_batch(tlb))
 			return true;
 		batch = tlb->active;
 	}
-	VM_BUG_ON_PAGE(batch->nr > batch->max, page);
+	VM_BUG_ON_PAGE(batch->nr > batch->max - 1, page);
 
 	return false;
 }
 
+bool __tlb_remove_folio_pages(struct mmu_gather *tlb, struct page *page,
+		unsigned int nr_pages, bool delay_rmap)
+{
+	return __tlb_remove_folio_pages_size(tlb, page, nr_pages, delay_rmap,
+					     PAGE_SIZE);
+}
+
+bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page,
+		bool delay_rmap, int page_size)
+{
+	return __tlb_remove_folio_pages_size(tlb, page, 1, delay_rmap, page_size);
+}
+
 #endif /* MMU_GATHER_NO_GATHER */
 
 #ifdef CONFIG_MMU_GATHER_TABLE_FREE