Update Linux to v5.10.109

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz

Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/mm/memremap.c b/mm/memremap.c
index c51c6bd..2455bac 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -7,6 +7,7 @@
 #include <linux/mm.h>
 #include <linux/pfn_t.h>
 #include <linux/swap.h>
+#include <linux/mmzone.h>
 #include <linux/swapops.h>
 #include <linux/types.h>
 #include <linux/wait_bit.h>
@@ -14,56 +15,91 @@
 
 static DEFINE_XARRAY(pgmap_array);
 
+/*
+ * The memremap() and memremap_pages() interfaces are alternately used
+ * to map persistent memory namespaces. These interfaces place different
+ * constraints on the alignment and size of the mapping (namespace).
+ * memremap() can map individual PAGE_SIZE pages. memremap_pages() can
+ * only map subsections (2MB), and at least one architecture (PowerPC)
+ * the minimum mapping granularity of memremap_pages() is 16MB.
+ *
+ * The role of memremap_compat_align() is to communicate the minimum
+ * arch supported alignment of a namespace such that it can freely
+ * switch modes without violating the arch constraint. Namely, do not
+ * allow a namespace to be PAGE_SIZE aligned since that namespace may be
+ * reconfigured into a mode that requires SUBSECTION_SIZE alignment.
+ */
+#ifndef CONFIG_ARCH_HAS_MEMREMAP_COMPAT_ALIGN
+unsigned long memremap_compat_align(void)
+{
+	return SUBSECTION_SIZE;
+}
+EXPORT_SYMBOL_GPL(memremap_compat_align);
+#endif
+
 #ifdef CONFIG_DEV_PAGEMAP_OPS
 DEFINE_STATIC_KEY_FALSE(devmap_managed_key);
 EXPORT_SYMBOL(devmap_managed_key);
-static atomic_t devmap_managed_enable;
 
-static void devmap_managed_enable_put(void)
+static void devmap_managed_enable_put(struct dev_pagemap *pgmap)
 {
-	if (atomic_dec_and_test(&devmap_managed_enable))
-		static_branch_disable(&devmap_managed_key);
+	if (pgmap->type == MEMORY_DEVICE_PRIVATE ||
+	    pgmap->type == MEMORY_DEVICE_FS_DAX)
+		static_branch_dec(&devmap_managed_key);
 }
 
-static int devmap_managed_enable_get(struct dev_pagemap *pgmap)
+static void devmap_managed_enable_get(struct dev_pagemap *pgmap)
 {
-	if (!pgmap->ops || !pgmap->ops->page_free) {
-		WARN(1, "Missing page_free method\n");
-		return -EINVAL;
-	}
-
-	if (atomic_inc_return(&devmap_managed_enable) == 1)
-		static_branch_enable(&devmap_managed_key);
-	return 0;
+	if (pgmap->type == MEMORY_DEVICE_PRIVATE ||
+	    pgmap->type == MEMORY_DEVICE_FS_DAX)
+		static_branch_inc(&devmap_managed_key);
 }
 #else
-static int devmap_managed_enable_get(struct dev_pagemap *pgmap)
+static void devmap_managed_enable_get(struct dev_pagemap *pgmap)
 {
-	return -EINVAL;
 }
-static void devmap_managed_enable_put(void)
+static void devmap_managed_enable_put(struct dev_pagemap *pgmap)
 {
 }
 #endif /* CONFIG_DEV_PAGEMAP_OPS */
 
-static void pgmap_array_delete(struct resource *res)
+static void pgmap_array_delete(struct range *range)
 {
-	xa_store_range(&pgmap_array, PHYS_PFN(res->start), PHYS_PFN(res->end),
+	xa_store_range(&pgmap_array, PHYS_PFN(range->start), PHYS_PFN(range->end),
 			NULL, GFP_KERNEL);
 	synchronize_rcu();
 }
 
-static unsigned long pfn_first(struct dev_pagemap *pgmap)
+static unsigned long pfn_first(struct dev_pagemap *pgmap, int range_id)
 {
-	return PHYS_PFN(pgmap->res.start) +
-		vmem_altmap_offset(pgmap_altmap(pgmap));
+	struct range *range = &pgmap->ranges[range_id];
+	unsigned long pfn = PHYS_PFN(range->start);
+
+	if (range_id)
+		return pfn;
+	return pfn + vmem_altmap_offset(pgmap_altmap(pgmap));
 }
 
-static unsigned long pfn_end(struct dev_pagemap *pgmap)
+bool pgmap_pfn_valid(struct dev_pagemap *pgmap, unsigned long pfn)
 {
-	const struct resource *res = &pgmap->res;
+	int i;
 
-	return (res->start + resource_size(res)) >> PAGE_SHIFT;
+	for (i = 0; i < pgmap->nr_range; i++) {
+		struct range *range = &pgmap->ranges[i];
+
+		if (pfn >= PHYS_PFN(range->start) &&
+		    pfn <= PHYS_PFN(range->end))
+			return pfn >= pfn_first(pgmap, i);
+	}
+
+	return false;
+}
+
+static unsigned long pfn_end(struct dev_pagemap *pgmap, int range_id)
+{
+	const struct range *range = &pgmap->ranges[range_id];
+
+	return (range->start + range_len(range)) >> PAGE_SHIFT;
 }
 
 static unsigned long pfn_next(unsigned long pfn)
@@ -73,8 +109,8 @@
 	return pfn + 1;
 }
 
-#define for_each_device_pfn(pfn, map) \
-	for (pfn = pfn_first(map); pfn < pfn_end(map); pfn = pfn_next(pfn))
+#define for_each_device_pfn(pfn, map, i) \
+	for (pfn = pfn_first(map, i); pfn < pfn_end(map, i); pfn = pfn_next(pfn))
 
 static void dev_pagemap_kill(struct dev_pagemap *pgmap)
 {
@@ -100,39 +136,51 @@
 		pgmap->ref = NULL;
 }
 
-void memunmap_pages(struct dev_pagemap *pgmap)
+static void pageunmap_range(struct dev_pagemap *pgmap, int range_id)
 {
-	struct resource *res = &pgmap->res;
+	struct range *range = &pgmap->ranges[range_id];
 	struct page *first_page;
-	unsigned long pfn;
 	int nid;
 
-	dev_pagemap_kill(pgmap);
-	for_each_device_pfn(pfn, pgmap)
-		put_page(pfn_to_page(pfn));
-	dev_pagemap_cleanup(pgmap);
-
 	/* make sure to access a memmap that was actually initialized */
-	first_page = pfn_to_page(pfn_first(pgmap));
+	first_page = pfn_to_page(pfn_first(pgmap, range_id));
 
 	/* pages are dead and unused, undo the arch mapping */
 	nid = page_to_nid(first_page);
 
 	mem_hotplug_begin();
+	remove_pfn_range_from_zone(page_zone(first_page), PHYS_PFN(range->start),
+				   PHYS_PFN(range_len(range)));
 	if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
-		__remove_pages(PHYS_PFN(res->start),
-			       PHYS_PFN(resource_size(res)), NULL);
+		__remove_pages(PHYS_PFN(range->start),
+			       PHYS_PFN(range_len(range)), NULL);
 	} else {
-		arch_remove_memory(nid, res->start, resource_size(res),
+		arch_remove_memory(nid, range->start, range_len(range),
 				pgmap_altmap(pgmap));
-		kasan_remove_zero_shadow(__va(res->start), resource_size(res));
+		kasan_remove_zero_shadow(__va(range->start), range_len(range));
 	}
 	mem_hotplug_done();
 
-	untrack_pfn(NULL, PHYS_PFN(res->start), resource_size(res));
-	pgmap_array_delete(res);
+	untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range));
+	pgmap_array_delete(range);
+}
+
+void memunmap_pages(struct dev_pagemap *pgmap)
+{
+	unsigned long pfn;
+	int i;
+
+	dev_pagemap_kill(pgmap);
+	for (i = 0; i < pgmap->nr_range; i++)
+		for_each_device_pfn(pfn, pgmap, i)
+			put_page(pfn_to_page(pfn));
+	dev_pagemap_cleanup(pgmap);
+
+	for (i = 0; i < pgmap->nr_range; i++)
+		pageunmap_range(pgmap, i);
+
 	WARN_ONCE(pgmap->altmap.alloc, "failed to free all reserved pages\n");
-	devmap_managed_enable_put();
+	devmap_managed_enable_put(pgmap);
 }
 EXPORT_SYMBOL_GPL(memunmap_pages);
 
@@ -149,6 +197,115 @@
 	complete(&pgmap->done);
 }
 
+static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params,
+		int range_id, int nid)
+{
+	struct range *range = &pgmap->ranges[range_id];
+	struct dev_pagemap *conflict_pgmap;
+	int error, is_ram;
+
+	if (WARN_ONCE(pgmap_altmap(pgmap) && range_id > 0,
+				"altmap not supported for multiple ranges\n"))
+		return -EINVAL;
+
+	conflict_pgmap = get_dev_pagemap(PHYS_PFN(range->start), NULL);
+	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);
+	if (conflict_pgmap) {
+		WARN(1, "Conflicting mapping in same section\n");
+		put_dev_pagemap(conflict_pgmap);
+		return -ENOMEM;
+	}
+
+	is_ram = region_intersects(range->start, range_len(range),
+		IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);
+
+	if (is_ram != REGION_DISJOINT) {
+		WARN_ONCE(1, "attempted on %s region %#llx-%#llx\n",
+				is_ram == REGION_MIXED ? "mixed" : "ram",
+				range->start, range->end);
+		return -ENXIO;
+	}
+
+	error = xa_err(xa_store_range(&pgmap_array, PHYS_PFN(range->start),
+				PHYS_PFN(range->end), pgmap, GFP_KERNEL));
+	if (error)
+		return error;
+
+	if (nid < 0)
+		nid = numa_mem_id();
+
+	error = track_pfn_remap(NULL, &params->pgprot, PHYS_PFN(range->start), 0,
+			range_len(range));
+	if (error)
+		goto err_pfn_remap;
+
+	mem_hotplug_begin();
+
+	/*
+	 * For device private memory we call add_pages() as we only need to
+	 * allocate and initialize struct page for the device memory. More-
+	 * over the device memory is un-accessible thus we do not want to
+	 * create a linear mapping for the memory like arch_add_memory()
+	 * would do.
+	 *
+	 * For all other device memory types, which are accessible by
+	 * the CPU, we do want the linear mapping and thus use
+	 * arch_add_memory().
+	 */
+	if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
+		error = add_pages(nid, PHYS_PFN(range->start),
+				PHYS_PFN(range_len(range)), params);
+	} else {
+		error = kasan_add_zero_shadow(__va(range->start), range_len(range));
+		if (error) {
+			mem_hotplug_done();
+			goto err_kasan;
+		}
+
+		error = arch_add_memory(nid, range->start, range_len(range),
+					params);
+	}
+
+	if (!error) {
+		struct zone *zone;
+
+		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);
+	}
+
+	mem_hotplug_done();
+	if (error)
+		goto err_add_memory;
+
+	/*
+	 * Initialization of the pages has been deferred until now in order
+	 * to allow us to do the work while not holding the hotplug lock.
+	 */
+	memmap_init_zone_device(&NODE_DATA(nid)->node_zones[ZONE_DEVICE],
+				PHYS_PFN(range->start),
+				PHYS_PFN(range_len(range)), pgmap);
+	percpu_ref_get_many(pgmap->ref, pfn_end(pgmap, range_id)
+			- pfn_first(pgmap, range_id));
+	return 0;
+
+err_add_memory:
+	kasan_remove_zero_shadow(__va(range->start), range_len(range));
+err_kasan:
+	untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range));
+err_pfn_remap:
+	pgmap_array_delete(range);
+	return error;
+}
+
+
 /*
  * Not device managed version of dev_memremap_pages, undone by
  * memunmap_pages().  Please use dev_memremap_pages if you have a struct
@@ -156,17 +313,15 @@
  */
 void *memremap_pages(struct dev_pagemap *pgmap, int nid)
 {
-	struct resource *res = &pgmap->res;
-	struct dev_pagemap *conflict_pgmap;
-	struct mhp_restrictions restrictions = {
-		/*
-		 * We do not want any optional features only our own memmap
-		 */
+	struct mhp_params params = {
 		.altmap = pgmap_altmap(pgmap),
+		.pgprot = PAGE_KERNEL,
 	};
-	pgprot_t pgprot = PAGE_KERNEL;
-	int error, is_ram;
-	bool need_devmap_managed = true;
+	const int nr_range = pgmap->nr_range;
+	int error, i;
+
+	if (WARN_ONCE(!nr_range, "nr_range must be specified\n"))
+		return ERR_PTR(-EINVAL);
 
 	switch (pgmap->type) {
 	case MEMORY_DEVICE_PRIVATE:
@@ -178,6 +333,14 @@
 			WARN(1, "Missing migrate_to_ram method\n");
 			return ERR_PTR(-EINVAL);
 		}
+		if (!pgmap->ops->page_free) {
+			WARN(1, "Missing page_free method\n");
+			return ERR_PTR(-EINVAL);
+		}
+		if (!pgmap->owner) {
+			WARN(1, "Missing owner\n");
+			return ERR_PTR(-EINVAL);
+		}
 		break;
 	case MEMORY_DEVICE_FS_DAX:
 		if (!IS_ENABLED(CONFIG_ZONE_DEVICE) ||
@@ -186,9 +349,10 @@
 			return ERR_PTR(-EINVAL);
 		}
 		break;
-	case MEMORY_DEVICE_DEVDAX:
+	case MEMORY_DEVICE_GENERIC:
+		break;
 	case MEMORY_DEVICE_PCI_P2PDMA:
-		need_devmap_managed = false;
+		params.pgprot = pgprot_noncached(params.pgprot);
 		break;
 	default:
 		WARN(1, "Invalid pgmap type %d\n", pgmap->type);
@@ -212,111 +376,29 @@
 		}
 	}
 
-	if (need_devmap_managed) {
-		error = devmap_managed_enable_get(pgmap);
+	devmap_managed_enable_get(pgmap);
+
+	/*
+	 * Clear the pgmap nr_range as it will be incremented for each
+	 * successfully processed range. This communicates how many
+	 * regions to unwind in the abort case.
+	 */
+	pgmap->nr_range = 0;
+	error = 0;
+	for (i = 0; i < nr_range; i++) {
+		error = pagemap_range(pgmap, &params, i, nid);
 		if (error)
-			return ERR_PTR(error);
+			break;
+		pgmap->nr_range++;
 	}
 
-	conflict_pgmap = get_dev_pagemap(PHYS_PFN(res->start), NULL);
-	if (conflict_pgmap) {
-		WARN(1, "Conflicting mapping in same section\n");
-		put_dev_pagemap(conflict_pgmap);
-		error = -ENOMEM;
-		goto err_array;
+	if (i < nr_range) {
+		memunmap_pages(pgmap);
+		pgmap->nr_range = nr_range;
+		return ERR_PTR(error);
 	}
 
-	conflict_pgmap = get_dev_pagemap(PHYS_PFN(res->end), NULL);
-	if (conflict_pgmap) {
-		WARN(1, "Conflicting mapping in same section\n");
-		put_dev_pagemap(conflict_pgmap);
-		error = -ENOMEM;
-		goto err_array;
-	}
-
-	is_ram = region_intersects(res->start, resource_size(res),
-		IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);
-
-	if (is_ram != REGION_DISJOINT) {
-		WARN_ONCE(1, "%s attempted on %s region %pr\n", __func__,
-				is_ram == REGION_MIXED ? "mixed" : "ram", res);
-		error = -ENXIO;
-		goto err_array;
-	}
-
-	error = xa_err(xa_store_range(&pgmap_array, PHYS_PFN(res->start),
-				PHYS_PFN(res->end), pgmap, GFP_KERNEL));
-	if (error)
-		goto err_array;
-
-	if (nid < 0)
-		nid = numa_mem_id();
-
-	error = track_pfn_remap(NULL, &pgprot, PHYS_PFN(res->start), 0,
-			resource_size(res));
-	if (error)
-		goto err_pfn_remap;
-
-	mem_hotplug_begin();
-
-	/*
-	 * For device private memory we call add_pages() as we only need to
-	 * allocate and initialize struct page for the device memory. More-
-	 * over the device memory is un-accessible thus we do not want to
-	 * create a linear mapping for the memory like arch_add_memory()
-	 * would do.
-	 *
-	 * For all other device memory types, which are accessible by
-	 * the CPU, we do want the linear mapping and thus use
-	 * arch_add_memory().
-	 */
-	if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
-		error = add_pages(nid, PHYS_PFN(res->start),
-				PHYS_PFN(resource_size(res)), &restrictions);
-	} else {
-		error = kasan_add_zero_shadow(__va(res->start), resource_size(res));
-		if (error) {
-			mem_hotplug_done();
-			goto err_kasan;
-		}
-
-		error = arch_add_memory(nid, res->start, resource_size(res),
-					&restrictions);
-	}
-
-	if (!error) {
-		struct zone *zone;
-
-		zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE];
-		move_pfn_range_to_zone(zone, PHYS_PFN(res->start),
-				PHYS_PFN(resource_size(res)), restrictions.altmap);
-	}
-
-	mem_hotplug_done();
-	if (error)
-		goto err_add_memory;
-
-	/*
-	 * Initialization of the pages has been deferred until now in order
-	 * to allow us to do the work while not holding the hotplug lock.
-	 */
-	memmap_init_zone_device(&NODE_DATA(nid)->node_zones[ZONE_DEVICE],
-				PHYS_PFN(res->start),
-				PHYS_PFN(resource_size(res)), pgmap);
-	percpu_ref_get_many(pgmap->ref, pfn_end(pgmap) - pfn_first(pgmap));
-	return __va(res->start);
-
- err_add_memory:
-	kasan_remove_zero_shadow(__va(res->start), resource_size(res));
- err_kasan:
-	untrack_pfn(NULL, PHYS_PFN(res->start), resource_size(res));
- err_pfn_remap:
-	pgmap_array_delete(res);
- err_array:
-	dev_pagemap_kill(pgmap);
-	dev_pagemap_cleanup(pgmap);
-	devmap_managed_enable_put();
-	return ERR_PTR(error);
+	return __va(pgmap->ranges[0].start);
 }
 EXPORT_SYMBOL_GPL(memremap_pages);
 
@@ -336,7 +418,7 @@
  *    'live' on entry and will be killed and reaped at
  *    devm_memremap_pages_release() time, or if this routine fails.
  *
- * 4/ res is expected to be a host memory range that could feasibly be
+ * 4/ range is expected to be a host memory range that could feasibly be
  *    treated as a "System RAM" range, i.e. not a device mmio range, but
  *    this is not enforced.
  */
@@ -393,7 +475,7 @@
 	 * In the cached case we're already holding a live reference.
 	 */
 	if (pgmap) {
-		if (phys >= pgmap->res.start && phys <= pgmap->res.end)
+		if (phys >= pgmap->range.start && phys <= pgmap->range.end)
 			return pgmap;
 		put_dev_pagemap(pgmap);
 	}
@@ -410,48 +492,40 @@
 EXPORT_SYMBOL_GPL(get_dev_pagemap);
 
 #ifdef CONFIG_DEV_PAGEMAP_OPS
-void __put_devmap_managed_page(struct page *page)
+void free_devmap_managed_page(struct page *page)
 {
-	int count = page_ref_dec_return(page);
+	/* notify page idle for dax */
+	if (!is_device_private_page(page)) {
+		wake_up_var(&page->_refcount);
+		return;
+	}
+
+	__ClearPageWaiters(page);
+
+	mem_cgroup_uncharge(page);
 
 	/*
-	 * If refcount is 1 then page is freed and refcount is stable as nobody
-	 * holds a reference on the page.
+	 * When a device_private page is freed, the page->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.
+	 *
+	 * 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.
 	 */
-	if (count == 1) {
-		/* Clear Active bit in case of parallel mark_page_accessed */
-		__ClearPageActive(page);
-		__ClearPageWaiters(page);
-
-		mem_cgroup_uncharge(page);
-
-		/*
-		 * When a device_private page is freed, the page->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.
-		 *
-		 * 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.
-		 */
-		if (is_device_private_page(page))
-			page->mapping = NULL;
-
-		page->pgmap->ops->page_free(page);
-	} else if (!count)
-		__put_page(page);
+	page->mapping = NULL;
+	page->pgmap->ops->page_free(page);
 }
-EXPORT_SYMBOL(__put_devmap_managed_page);
 #endif /* CONFIG_DEV_PAGEMAP_OPS */