Merge branch 'akpm' (patches from Andrew)

Merge yet more updates from Andrew Morton:
 "Subsystems affected by this patch series: mm (memcg, migration,
  pagemap, gup, madvise, vmalloc), ia64, and misc"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (31 commits)
  mm: remove duplicate include statement in mmu.c
  mm: remove the filename in the top of file comment in vmalloc.c
  mm: cleanup the gfp_mask handling in __vmalloc_area_node
  mm: remove alloc_vm_area
  x86/xen: open code alloc_vm_area in arch_gnttab_valloc
  xen/xenbus: use apply_to_page_range directly in xenbus_map_ring_pv
  drm/i915: use vmap in i915_gem_object_map
  drm/i915: stop using kmap in i915_gem_object_map
  drm/i915: use vmap in shmem_pin_map
  zsmalloc: switch from alloc_vm_area to get_vm_area
  mm: allow a NULL fn callback in apply_to_page_range
  mm: add a vmap_pfn function
  mm: add a VM_MAP_PUT_PAGES flag for vmap
  mm: update the documentation for vfree
  mm/madvise: introduce process_madvise() syscall: an external memory hinting API
  pid: move pidfd_get_pid() to pid.c
  mm/madvise: pass mm to do_madvise
  selftests/vm: 10x speedup for hmm-tests
  binfmt_elf: take the mmap lock around find_extend_vma()
  mm/gup_benchmark: take the mmap lock around GUP
  ...

4 files changed, 95 insertions, 144 deletions

diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig
index 9afa5c4a6bf0..1e1cb245fca7 100644
--- a/drivers/gpu/drm/i915/Kconfig
+++ b/drivers/gpu/drm/i915/Kconfig
@@ -25,6 +25,7 @@ config DRM_I915
 	select CRC32
 	select SND_HDA_I915 if SND_HDA_CORE
 	select CEC_CORE if CEC_NOTIFIER
+	select VMAP_PFN
 	help
 	  Choose this option if you have a system that has "Intel Graphics
 	  Media Accelerator" or "HD Graphics" integrated graphics,
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
index d6eeefab3d01..f60ca6dc911f 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c
@@ -162,8 +162,6 @@ static void unmap_object(struct drm_i915_gem_object *obj, void *ptr)
 {
 	if (is_vmalloc_addr(ptr))
 		vunmap(ptr);
-	else
-		kunmap(kmap_to_page(ptr));
 }
 
 struct sg_table *
@@ -234,34 +232,21 @@ unlock:
 	return err;
 }
 
-static inline pte_t iomap_pte(resource_size_t base,
-			      dma_addr_t offset,
-			      pgprot_t prot)
-{
-	return pte_mkspecial(pfn_pte((base + offset) >> PAGE_SHIFT, prot));
-}
-
 /* The 'mapping' part of i915_gem_object_pin_map() below */
-static void *i915_gem_object_map(struct drm_i915_gem_object *obj,
-				 enum i915_map_type type)
+static void *i915_gem_object_map_page(struct drm_i915_gem_object *obj,
+		enum i915_map_type type)
 {
-	unsigned long n_pte = obj->base.size >> PAGE_SHIFT;
-	struct sg_table *sgt = obj->mm.pages;
-	pte_t *stack[32], **mem;
-	struct vm_struct *area;
+	unsigned long n_pages = obj->base.size >> PAGE_SHIFT, i;
+	struct page *stack[32], **pages = stack, *page;
+	struct sgt_iter iter;
 	pgprot_t pgprot;
+	void *vaddr;
 
-	if (!i915_gem_object_has_struct_page(obj) && type != I915_MAP_WC)
-		return NULL;
-
-	if (GEM_WARN_ON(type == I915_MAP_WC &&
-			!static_cpu_has(X86_FEATURE_PAT)))
-		return NULL;
-
-	/* A single page can always be kmapped */
-	if (n_pte == 1 && type == I915_MAP_WB) {
-		struct page *page = sg_page(sgt->sgl);
-
+	switch (type) {
+	default:
+		MISSING_CASE(type);
+		fallthrough;	/* to use PAGE_KERNEL anyway */
+	case I915_MAP_WB:
 		/*
 		 * On 32b, highmem using a finite set of indirect PTE (i.e.
 		 * vmap) to provide virtual mappings of the high pages.
@@ -277,33 +262,10 @@ static void *i915_gem_object_map(struct drm_i915_gem_object *obj,
 		 * forever.
 		 *
 		 * So if the page is beyond the 32b boundary, make an explicit
-		 * vmap. On 64b, this check will be optimised away as we can
-		 * directly kmap any page on the system.
+		 * vmap.
 		 */
-		if (!PageHighMem(page))
-			return kmap(page);
-	}
-
-	mem = stack;
-	if (n_pte > ARRAY_SIZE(stack)) {
-		/* Too big for stack -- allocate temporary array instead */
-		mem = kvmalloc_array(n_pte, sizeof(*mem), GFP_KERNEL);
-		if (!mem)
-			return NULL;
-	}
-
-	area = alloc_vm_area(obj->base.size, mem);
-	if (!area) {
-		if (mem != stack)
-			kvfree(mem);
-		return NULL;
-	}
-
-	switch (type) {
-	default:
-		MISSING_CASE(type);
-		fallthrough;	/* to use PAGE_KERNEL anyway */
-	case I915_MAP_WB:
+		if (n_pages == 1 && !PageHighMem(sg_page(obj->mm.pages->sgl)))
+			return page_address(sg_page(obj->mm.pages->sgl));
 		pgprot = PAGE_KERNEL;
 		break;
 	case I915_MAP_WC:
@@ -311,30 +273,50 @@ static void *i915_gem_object_map(struct drm_i915_gem_object *obj,
 		break;
 	}
 
-	if (i915_gem_object_has_struct_page(obj)) {
-		struct sgt_iter iter;
-		struct page *page;
-		pte_t **ptes = mem;
+	if (n_pages > ARRAY_SIZE(stack)) {
+		/* Too big for stack -- allocate temporary array instead */
+		pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL);
+		if (!pages)
+			return NULL;
+	}
 
-		for_each_sgt_page(page, iter, sgt)
-			**ptes++ = mk_pte(page, pgprot);
-	} else {
-		resource_size_t iomap;
-		struct sgt_iter iter;
-		pte_t **ptes = mem;
-		dma_addr_t addr;
+	i = 0;
+	for_each_sgt_page(page, iter, obj->mm.pages)
+		pages[i++] = page;
+	vaddr = vmap(pages, n_pages, 0, pgprot);
+	if (pages != stack)
+		kvfree(pages);
+	return vaddr;
+}
 
-		iomap = obj->mm.region->iomap.base;
-		iomap -= obj->mm.region->region.start;
+static void *i915_gem_object_map_pfn(struct drm_i915_gem_object *obj,
+		enum i915_map_type type)
+{
+	resource_size_t iomap = obj->mm.region->iomap.base -
+		obj->mm.region->region.start;
+	unsigned long n_pfn = obj->base.size >> PAGE_SHIFT;
+	unsigned long stack[32], *pfns = stack, i;
+	struct sgt_iter iter;
+	dma_addr_t addr;
+	void *vaddr;
+
+	if (type != I915_MAP_WC)
+		return NULL;
 
-		for_each_sgt_daddr(addr, iter, sgt)
-			**ptes++ = iomap_pte(iomap, addr, pgprot);
+	if (n_pfn > ARRAY_SIZE(stack)) {
+		/* Too big for stack -- allocate temporary array instead */
+		pfns = kvmalloc_array(n_pfn, sizeof(*pfns), GFP_KERNEL);
+		if (!pfns)
+			return NULL;
 	}
 
-	if (mem != stack)
-		kvfree(mem);
-
-	return area->addr;
+	i = 0;
+	for_each_sgt_daddr(addr, iter, obj->mm.pages)
+		pfns[i++] = (iomap + addr) >> PAGE_SHIFT;
+	vaddr = vmap_pfn(pfns, n_pfn, pgprot_writecombine(PAGE_KERNEL_IO));
+	if (pfns != stack)
+		kvfree(pfns);
+	return vaddr;
 }
 
 /* get, pin, and map the pages of the object into kernel space */
@@ -386,7 +368,13 @@ void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj,
 	}
 
 	if (!ptr) {
-		ptr = i915_gem_object_map(obj, type);
+		if (GEM_WARN_ON(type == I915_MAP_WC &&
+				!static_cpu_has(X86_FEATURE_PAT)))
+			ptr = NULL;
+		else if (i915_gem_object_has_struct_page(obj))
+			ptr = i915_gem_object_map_page(obj, type);
+		else
+			ptr = i915_gem_object_map_pfn(obj, type);
 		if (!ptr) {
 			err = -ENOMEM;
 			goto err_unpin;
diff --git a/drivers/gpu/drm/i915/gt/shmem_utils.c b/drivers/gpu/drm/i915/gt/shmem_utils.c
index 43c7acbdc79d..f011ea42487e 100644
--- a/drivers/gpu/drm/i915/gt/shmem_utils.c
+++ b/drivers/gpu/drm/i915/gt/shmem_utils.c
@@ -49,80 +49,40 @@ struct file *shmem_create_from_object(struct drm_i915_gem_object *obj)
 	return file;
 }
 
-static size_t shmem_npte(struct file *file)
-{
-	return file->f_mapping->host->i_size >> PAGE_SHIFT;
-}
-
-static void __shmem_unpin_map(struct file *file, void *ptr, size_t n_pte)
-{
-	unsigned long pfn;
-
-	vunmap(ptr);
-
-	for (pfn = 0; pfn < n_pte; pfn++) {
-		struct page *page;
-
-		page = shmem_read_mapping_page_gfp(file->f_mapping, pfn,
-						   GFP_KERNEL);
-		if (!WARN_ON(IS_ERR(page))) {
-			put_page(page);
-			put_page(page);
-		}
-	}
-}
-
 void *shmem_pin_map(struct file *file)
 {
-	const size_t n_pte = shmem_npte(file);
-	pte_t *stack[32], **ptes, **mem;
-	struct vm_struct *area;
-	unsigned long pfn;
-
-	mem = stack;
-	if (n_pte > ARRAY_SIZE(stack)) {
-		mem = kvmalloc_array(n_pte, sizeof(*mem), GFP_KERNEL);
-		if (!mem)
-			return NULL;
-	}
+	struct page **pages;
+	size_t n_pages, i;
+	void *vaddr;
 
-	area = alloc_vm_area(n_pte << PAGE_SHIFT, mem);
-	if (!area) {
-		if (mem != stack)
-			kvfree(mem);
+	n_pages = file->f_mapping->host->i_size >> PAGE_SHIFT;
+	pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL);
+	if (!pages)
 		return NULL;
-	}
 
-	ptes = mem;
-	for (pfn = 0; pfn < n_pte; pfn++) {
-		struct page *page;
-
-		page = shmem_read_mapping_page_gfp(file->f_mapping, pfn,
-						   GFP_KERNEL);
-		if (IS_ERR(page))
+	for (i = 0; i < n_pages; i++) {
+		pages[i] = shmem_read_mapping_page_gfp(file->f_mapping, i,
+						       GFP_KERNEL);
+		if (IS_ERR(pages[i]))
 			goto err_page;
-
-		**ptes++ = mk_pte(page,  PAGE_KERNEL);
 	}
 
-	if (mem != stack)
-		kvfree(mem);
-
+	vaddr = vmap(pages, n_pages, VM_MAP_PUT_PAGES, PAGE_KERNEL);
+	if (!vaddr)
+		goto err_page;
 	mapping_set_unevictable(file->f_mapping);
-	return area->addr;
-
+	return vaddr;
 err_page:
-	if (mem != stack)
-		kvfree(mem);
-
-	__shmem_unpin_map(file, area->addr, pfn);
+	while (--i >= 0)
+		put_page(pages[i]);
+	kvfree(pages);
 	return NULL;
 }
 
 void shmem_unpin_map(struct file *file, void *ptr)
 {
 	mapping_clear_unevictable(file->f_mapping);
-	__shmem_unpin_map(file, ptr, shmem_npte(file));
+	vfree(ptr);
 }
 
 static int __shmem_rw(struct file *file, loff_t off,
diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
index 2690318ad50f..fd80e318b99c 100644
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -73,16 +73,13 @@ struct map_ring_valloc {
 	struct xenbus_map_node *node;
 
 	/* Why do we need two arrays? See comment of __xenbus_map_ring */
-	union {
-		unsigned long addrs[XENBUS_MAX_RING_GRANTS];
-		pte_t *ptes[XENBUS_MAX_RING_GRANTS];
-	};
+	unsigned long addrs[XENBUS_MAX_RING_GRANTS];
 	phys_addr_t phys_addrs[XENBUS_MAX_RING_GRANTS];
 
 	struct gnttab_map_grant_ref map[XENBUS_MAX_RING_GRANTS];
 	struct gnttab_unmap_grant_ref unmap[XENBUS_MAX_RING_GRANTS];
 
-	unsigned int idx;	/* HVM only. */
+	unsigned int idx;
 };
 
 static DEFINE_SPINLOCK(xenbus_valloc_lock);
@@ -686,6 +683,14 @@ int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr)
 EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree);
 
 #ifdef CONFIG_XEN_PV
+static int map_ring_apply(pte_t *pte, unsigned long addr, void *data)
+{
+	struct map_ring_valloc *info = data;
+
+	info->phys_addrs[info->idx++] = arbitrary_virt_to_machine(pte).maddr;
+	return 0;
+}
+
 static int xenbus_map_ring_pv(struct xenbus_device *dev,
 			      struct map_ring_valloc *info,
 			      grant_ref_t *gnt_refs,
@@ -694,18 +699,15 @@ static int xenbus_map_ring_pv(struct xenbus_device *dev,
 {
 	struct xenbus_map_node *node = info->node;
 	struct vm_struct *area;
-	int err = GNTST_okay;
-	int i;
-	bool leaked;
+	bool leaked = false;
+	int err = -ENOMEM;
 
-	area = alloc_vm_area(XEN_PAGE_SIZE * nr_grefs, info->ptes);
+	area = get_vm_area(XEN_PAGE_SIZE * nr_grefs, VM_IOREMAP);
 	if (!area)
 		return -ENOMEM;
-
-	for (i = 0; i < nr_grefs; i++)
-		info->phys_addrs[i] =
-			arbitrary_virt_to_machine(info->ptes[i]).maddr;
-
+	if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
+				XEN_PAGE_SIZE * nr_grefs, map_ring_apply, info))
+		goto failed;
 	err = __xenbus_map_ring(dev, gnt_refs, nr_grefs, node->handles,
 				info, GNTMAP_host_map | GNTMAP_contains_pte,
 				&leaked);