1 files changed, 74 insertions, 127 deletions

diff --git a/mm/memremap.c b/mm/memremap.c
index 08cbf54fe037..4c2e0d68eb27 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -5,8 +5,8 @@
 #include <linux/kasan.h>
 #include <linux/memory_hotplug.h>
 #include <linux/memremap.h>
-#include <linux/pfn_t.h>
 #include <linux/swap.h>
+#include <linux/mm.h>
 #include <linux/mmzone.h>
 #include <linux/swapops.h>
 #include <linux/types.h>
@@ -38,30 +38,6 @@ unsigned long memremap_compat_align(void)
 EXPORT_SYMBOL_GPL(memremap_compat_align);
 #endif
 
-#ifdef CONFIG_FS_DAX
-DEFINE_STATIC_KEY_FALSE(devmap_managed_key);
-EXPORT_SYMBOL(devmap_managed_key);
-
-static void devmap_managed_enable_put(struct dev_pagemap *pgmap)
-{
-	if (pgmap->type == MEMORY_DEVICE_FS_DAX)
-		static_branch_dec(&devmap_managed_key);
-}
-
-static void devmap_managed_enable_get(struct dev_pagemap *pgmap)
-{
-	if (pgmap->type == MEMORY_DEVICE_FS_DAX)
-		static_branch_inc(&devmap_managed_key);
-}
-#else
-static void devmap_managed_enable_get(struct dev_pagemap *pgmap)
-{
-}
-static void devmap_managed_enable_put(struct dev_pagemap *pgmap)
-{
-}
-#endif /* CONFIG_FS_DAX */
-
 static void pgmap_array_delete(struct range *range)
 {
 	xa_store_range(&pgmap_array, PHYS_PFN(range->start), PHYS_PFN(range->end),
@@ -129,7 +105,7 @@ static void pageunmap_range(struct dev_pagemap *pgmap, int range_id)
 	}
 	mem_hotplug_done();
 
-	untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range));
+	pfnmap_untrack(PHYS_PFN(range->start), range_len(range));
 	pgmap_array_delete(range);
 }
 
@@ -150,7 +126,6 @@ void memunmap_pages(struct dev_pagemap *pgmap)
 	percpu_ref_exit(&pgmap->ref);
 
 	WARN_ONCE(pgmap->altmap.alloc, "failed to free all reserved pages\n");
-	devmap_managed_enable_put(pgmap);
 }
 EXPORT_SYMBOL_GPL(memunmap_pages);
 
@@ -178,14 +153,14 @@ static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params,
 				"altmap not supported for multiple ranges\n"))
 		return -EINVAL;
 
-	conflict_pgmap = get_dev_pagemap(PHYS_PFN(range->start), NULL);
+	conflict_pgmap = get_dev_pagemap(PHYS_PFN(range->start));
 	if (conflict_pgmap) {
 		WARN(1, "Conflicting mapping in same section\n");
 		put_dev_pagemap(conflict_pgmap);
 		return -ENOMEM;
 	}
 
-	conflict_pgmap = get_dev_pagemap(PHYS_PFN(range->end), NULL);
+	conflict_pgmap = get_dev_pagemap(PHYS_PFN(range->end));
 	if (conflict_pgmap) {
 		WARN(1, "Conflicting mapping in same section\n");
 		put_dev_pagemap(conflict_pgmap);
@@ -210,8 +185,8 @@ static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params,
 	if (nid < 0)
 		nid = numa_mem_id();
 
-	error = track_pfn_remap(NULL, &params->pgprot, PHYS_PFN(range->start), 0,
-			range_len(range));
+	error = pfnmap_track(PHYS_PFN(range->start), range_len(range),
+			     &params->pgprot);
 	if (error)
 		goto err_pfn_remap;
 
@@ -253,7 +228,7 @@ static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params,
 		zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE];
 		move_pfn_range_to_zone(zone, PHYS_PFN(range->start),
 				PHYS_PFN(range_len(range)), params->altmap,
-				MIGRATE_MOVABLE);
+				MIGRATE_MOVABLE, false);
 	}
 
 	mem_hotplug_done();
@@ -276,7 +251,7 @@ err_add_memory:
 	if (!is_private)
 		kasan_remove_zero_shadow(__va(range->start), range_len(range));
 err_kasan:
-	untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range));
+	pfnmap_untrack(PHYS_PFN(range->start), range_len(range));
 err_pfn_remap:
 	pgmap_array_delete(range);
 	return error;
@@ -300,6 +275,9 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 
 	if (WARN_ONCE(!nr_range, "nr_range must be specified\n"))
 		return ERR_PTR(-EINVAL);
+	if (WARN_ONCE(pgmap->vmemmap_shift > MAX_FOLIO_ORDER,
+		      "requested folio size unsupported\n"))
+		return ERR_PTR(-EINVAL);
 
 	switch (pgmap->type) {
 	case MEMORY_DEVICE_PRIVATE:
@@ -311,8 +289,8 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 			WARN(1, "Missing migrate_to_ram method\n");
 			return ERR_PTR(-EINVAL);
 		}
-		if (!pgmap->ops->page_free) {
-			WARN(1, "Missing page_free method\n");
+		if (!pgmap->ops->folio_free) {
+			WARN(1, "Missing folio_free method\n");
 			return ERR_PTR(-EINVAL);
 		}
 		if (!pgmap->owner) {
@@ -321,8 +299,8 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 		}
 		break;
 	case MEMORY_DEVICE_COHERENT:
-		if (!pgmap->ops->page_free) {
-			WARN(1, "Missing page_free method\n");
+		if (!pgmap->ops->folio_free) {
+			WARN(1, "Missing folio_free method\n");
 			return ERR_PTR(-EINVAL);
 		}
 		if (!pgmap->owner) {
@@ -331,10 +309,6 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 		}
 		break;
 	case MEMORY_DEVICE_FS_DAX:
-		if (IS_ENABLED(CONFIG_FS_DAX_LIMITED)) {
-			WARN(1, "File system DAX not supported\n");
-			return ERR_PTR(-EINVAL);
-		}
 		params.pgprot = pgprot_decrypted(params.pgprot);
 		break;
 	case MEMORY_DEVICE_GENERIC:
@@ -353,8 +327,6 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 	if (error)
 		return ERR_PTR(error);
 
-	devmap_managed_enable_get(pgmap);
-
 	/*
 	 * Clear the pgmap nr_range as it will be incremented for each
 	 * successfully processed range. This communicates how many
@@ -385,7 +357,7 @@ EXPORT_SYMBOL_GPL(memremap_pages);
  * @pgmap: pointer to a struct dev_pagemap
  *
  * Notes:
- * 1/ At a minimum the res and type members of @pgmap must be initialized
+ * 1/ At a minimum the range and type members of @pgmap must be initialized
  *    by the caller before passing it to this function
  *
  * 2/ The altmap field may optionally be initialized, in which case
@@ -422,42 +394,15 @@ void devm_memunmap_pages(struct device *dev, struct dev_pagemap *pgmap)
 }
 EXPORT_SYMBOL_GPL(devm_memunmap_pages);
 
-unsigned long vmem_altmap_offset(struct vmem_altmap *altmap)
-{
-	/* number of pfns from base where pfn_to_page() is valid */
-	if (altmap)
-		return altmap->reserve + altmap->free;
-	return 0;
-}
-
-void vmem_altmap_free(struct vmem_altmap *altmap, unsigned long nr_pfns)
-{
-	altmap->alloc -= nr_pfns;
-}
-
 /**
  * get_dev_pagemap() - take a new live reference on the dev_pagemap for @pfn
  * @pfn: page frame number to lookup page_map
- * @pgmap: optional known pgmap that already has a reference
- *
- * If @pgmap is non-NULL and covers @pfn it will be returned as-is.  If @pgmap
- * is non-NULL but does not cover @pfn the reference to it will be released.
  */
-struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
-		struct dev_pagemap *pgmap)
+struct dev_pagemap *get_dev_pagemap(unsigned long pfn)
 {
+	struct dev_pagemap *pgmap;
 	resource_size_t phys = PFN_PHYS(pfn);
 
-	/*
-	 * In the cached case we're already holding a live reference.
-	 */
-	if (pgmap) {
-		if (phys >= pgmap->range.start && phys <= pgmap->range.end)
-			return pgmap;
-		put_dev_pagemap(pgmap);
-	}
-
-	/* fall back to slow path lookup */
 	rcu_read_lock();
 	pgmap = xa_load(&pgmap_array, PHYS_PFN(phys));
 	if (pgmap && !percpu_ref_tryget_live_rcu(&pgmap->ref))
@@ -468,83 +413,85 @@ struct dev_pagemap *get_dev_pagemap(unsigned long pfn,
 }
 EXPORT_SYMBOL_GPL(get_dev_pagemap);
 
-void free_zone_device_page(struct page *page)
+void free_zone_device_folio(struct folio *folio)
 {
-	if (WARN_ON_ONCE(!page->pgmap->ops || !page->pgmap->ops->page_free))
+	struct dev_pagemap *pgmap = folio->pgmap;
+	unsigned long nr = folio_nr_pages(folio);
+	int i;
+
+	if (WARN_ON_ONCE(!pgmap))
 		return;
 
-	mem_cgroup_uncharge(page_folio(page));
+	mem_cgroup_uncharge(folio);
 
-	/*
-	 * Note: we don't expect anonymous compound pages yet. Once supported
-	 * and we could PTE-map them similar to THP, we'd have to clear
-	 * PG_anon_exclusive on all tail pages.
-	 */
-	VM_BUG_ON_PAGE(PageAnon(page) && PageCompound(page), page);
-	if (PageAnon(page))
-		__ClearPageAnonExclusive(page);
+	if (folio_test_anon(folio)) {
+		for (i = 0; i < nr; i++)
+			__ClearPageAnonExclusive(folio_page(folio, i));
+	} else {
+		VM_WARN_ON_ONCE(folio_test_large(folio));
+	}
 
 	/*
-	 * When a device managed page is freed, the page->mapping field
+	 * When a device managed page is freed, the folio->mapping field
 	 * may still contain a (stale) mapping value. For example, the
-	 * lower bits of page->mapping may still identify the page as an
-	 * anonymous page. Ultimately, this entire field is just stale
-	 * and wrong, and it will cause errors if not cleared.  One
-	 * example is:
-	 *
-	 *  migrate_vma_pages()
-	 *    migrate_vma_insert_page()
-	 *      page_add_new_anon_rmap()
-	 *        __page_set_anon_rmap()
-	 *          ...checks page->mapping, via PageAnon(page) call,
-	 *            and incorrectly concludes that the page is an
-	 *            anonymous page. Therefore, it incorrectly,
-	 *            silently fails to set up the new anon rmap.
+	 * lower bits of folio->mapping may still identify the folio as an
+	 * anonymous folio. Ultimately, this entire field is just stale
+	 * and wrong, and it will cause errors if not cleared.
 	 *
 	 * For other types of ZONE_DEVICE pages, migration is either
 	 * handled differently or not done at all, so there is no need
-	 * to clear page->mapping.
+	 * to clear folio->mapping.
+	 *
+	 * FS DAX pages clear the mapping when the folio->share count hits
+	 * zero which indicating the page has been removed from the file
+	 * system mapping.
 	 */
-	page->mapping = NULL;
-	page->pgmap->ops->page_free(page);
+	if (pgmap->type != MEMORY_DEVICE_FS_DAX &&
+	    pgmap->type != MEMORY_DEVICE_GENERIC)
+		folio->mapping = NULL;
 
-	if (page->pgmap->type != MEMORY_DEVICE_PRIVATE &&
-	    page->pgmap->type != MEMORY_DEVICE_COHERENT)
+	switch (pgmap->type) {
+	case MEMORY_DEVICE_PRIVATE:
+	case MEMORY_DEVICE_COHERENT:
+		if (WARN_ON_ONCE(!pgmap->ops || !pgmap->ops->folio_free))
+			break;
+		pgmap->ops->folio_free(folio);
+		percpu_ref_put_many(&folio->pgmap->ref, nr);
+		break;
+
+	case MEMORY_DEVICE_GENERIC:
 		/*
-		 * Reset the page count to 1 to prepare for handing out the page
+		 * Reset the refcount to 1 to prepare for handing out the page
 		 * again.
 		 */
-		set_page_count(page, 1);
-	else
-		put_dev_pagemap(page->pgmap);
+		folio_set_count(folio, 1);
+		break;
+
+	case MEMORY_DEVICE_FS_DAX:
+		wake_up_var(&folio->page);
+		break;
+
+	case MEMORY_DEVICE_PCI_P2PDMA:
+		if (WARN_ON_ONCE(!pgmap->ops || !pgmap->ops->folio_free))
+			break;
+		pgmap->ops->folio_free(folio);
+		break;
+	}
 }
 
-void zone_device_page_init(struct page *page)
+void zone_device_page_init(struct page *page, unsigned int order)
 {
+	VM_WARN_ON_ONCE(order > MAX_ORDER_NR_PAGES);
+
 	/*
 	 * Drivers shouldn't be allocating pages after calling
 	 * memunmap_pages().
 	 */
-	WARN_ON_ONCE(!percpu_ref_tryget_live(&page->pgmap->ref));
+	WARN_ON_ONCE(!percpu_ref_tryget_many(&page_pgmap(page)->ref, 1 << order));
 	set_page_count(page, 1);
 	lock_page(page);
-}
-EXPORT_SYMBOL_GPL(zone_device_page_init);
-
-#ifdef CONFIG_FS_DAX
-bool __put_devmap_managed_page_refs(struct page *page, int refs)
-{
-	if (page->pgmap->type != MEMORY_DEVICE_FS_DAX)
-		return false;
 
-	/*
-	 * fsdax page refcounts are 1-based, rather than 0-based: if
-	 * refcount is 1, then the page is free and the refcount is
-	 * stable because nobody holds a reference on the page.
-	 */
-	if (page_ref_sub_return(page, refs) == 1)
-		wake_up_var(&page->_refcount);
-	return true;
+	if (order)
+		prep_compound_page(page, order);
 }
-EXPORT_SYMBOL(__put_devmap_managed_page_refs);
-#endif /* CONFIG_FS_DAX */
+EXPORT_SYMBOL_GPL(zone_device_page_init);