+ x86-xen-open-code-alloc_vm_area-in-arch_gnttab_valloc.patch added to -mm tree

[akpm@linux-foundation.org]

The patch titled
     Subject: x86/xen: open code alloc_vm_area in arch_gnttab_valloc
has been added to the -mm tree.  Its filename is
     x86-xen-open-code-alloc_vm_area-in-arch_gnttab_valloc.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/x86-xen-open-code-alloc_vm_area-in-arch_gnttab_valloc.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/x86-xen-open-code-alloc_vm_area-in-arch_gnttab_valloc.patch

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------------------------------------------------------
From: Christoph Hellwig <hch@lst.de>
Subject: x86/xen: open code alloc_vm_area in arch_gnttab_valloc

Open code alloc_vm_area in the last remaining caller.

Link: https://lkml.kernel.org/r/20200918163724.2511-7-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/x86/xen/grant-table.c |   27 ++++++++++++++-----
 include/linux/vmalloc.h    |    5 ---
 mm/nommu.c                 |    7 -----
 mm/vmalloc.c               |   48 -----------------------------------
 4 files changed, 21 insertions(+), 66 deletions(-)

--- a/arch/x86/xen/grant-table.c~x86-xen-open-code-alloc_vm_area-in-arch_gnttab_valloc
+++ a/arch/x86/xen/grant-table.c
@@ -90,19 +90,32 @@ void arch_gnttab_unmap(void *shared, uns
 	}
 }
 
+static int gnttab_apply(pte_t *pte, unsigned long addr, void *data)
+{
+	pte_t ***p = data;
+
+	**p = pte;
+	(*p)++;
+	return 0;
+}
+
 static int arch_gnttab_valloc(struct gnttab_vm_area *area, unsigned nr_frames)
 {
 	area->ptes = kmalloc_array(nr_frames, sizeof(*area->ptes), GFP_KERNEL);
 	if (area->ptes == NULL)
 		return -ENOMEM;
-
-	area->area = alloc_vm_area(PAGE_SIZE * nr_frames, area->ptes);
-	if (area->area == NULL) {
-		kfree(area->ptes);
-		return -ENOMEM;
-	}
-
+	area->area = get_vm_area(PAGE_SIZE * nr_frames, VM_IOREMAP);
+	if (!area->area)
+		goto out_free_ptes;
+	if (apply_to_page_range(&init_mm, (unsigned long)area->area->addr,
+			PAGE_SIZE * nr_frames, gnttab_apply, &area->ptes))
+		goto out_free_vm_area;
 	return 0;
+out_free_vm_area:
+	free_vm_area(area->area);
+out_free_ptes:
+	kfree(area->ptes);
+	return -ENOMEM;
 }
 
 static void arch_gnttab_vfree(struct gnttab_vm_area *area)
--- a/include/linux/vmalloc.h~x86-xen-open-code-alloc_vm_area-in-arch_gnttab_valloc
+++ a/include/linux/vmalloc.h
@@ -168,6 +168,7 @@ extern struct vm_struct *__get_vm_area_c
 					unsigned long flags,
 					unsigned long start, unsigned long end,
 					const void *caller);
+void free_vm_area(struct vm_struct *area);
 extern struct vm_struct *remove_vm_area(const void *addr);
 extern struct vm_struct *find_vm_area(const void *addr);
 
@@ -203,10 +204,6 @@ static inline void set_vm_flush_reset_pe
 }
 #endif
 
-/* Allocate/destroy a 'vmalloc' VM area. */
-extern struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes);
-extern void free_vm_area(struct vm_struct *area);
-
 /* for /dev/kmem */
 extern long vread(char *buf, char *addr, unsigned long count);
 extern long vwrite(char *buf, char *addr, unsigned long count);
--- a/mm/nommu.c~x86-xen-open-code-alloc_vm_area-in-arch_gnttab_valloc
+++ a/mm/nommu.c
@@ -354,13 +354,6 @@ void vm_unmap_aliases(void)
 }
 EXPORT_SYMBOL_GPL(vm_unmap_aliases);
 
-struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
-{
-	BUG();
-	return NULL;
-}
-EXPORT_SYMBOL_GPL(alloc_vm_area);
-
 void free_vm_area(struct vm_struct *area)
 {
 	BUG();
--- a/mm/vmalloc.c~x86-xen-open-code-alloc_vm_area-in-arch_gnttab_valloc
+++ a/mm/vmalloc.c
@@ -3077,54 +3077,6 @@ int remap_vmalloc_range(struct vm_area_s
 }
 EXPORT_SYMBOL(remap_vmalloc_range);
 
-static int f(pte_t *pte, unsigned long addr, void *data)
-{
-	pte_t ***p = data;
-
-	if (p) {
-		*(*p) = pte;
-		(*p)++;
-	}
-	return 0;
-}
-
-/**
- * alloc_vm_area - allocate a range of kernel address space
- * @size:	   size of the area
- * @ptes:	   returns the PTEs for the address space
- *
- * Returns:	NULL on failure, vm_struct on success
- *
- * This function reserves a range of kernel address space, and
- * allocates pagetables to map that range.  No actual mappings
- * are created.
- *
- * If @ptes is non-NULL, pointers to the PTEs (in init_mm)
- * allocated for the VM area are returned.
- */
-struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes)
-{
-	struct vm_struct *area;
-
-	area = get_vm_area_caller(size, VM_IOREMAP,
-				__builtin_return_address(0));
-	if (area == NULL)
-		return NULL;
-
-	/*
-	 * This ensures that page tables are constructed for this region
-	 * of kernel virtual address space and mapped into init_mm.
-	 */
-	if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
-				size, f, ptes ? &ptes : NULL)) {
-		free_vm_area(area);
-		return NULL;
-	}
-
-	return area;
-}
-EXPORT_SYMBOL_GPL(alloc_vm_area);
-
 void free_vm_area(struct vm_struct *area)
 {
 	struct vm_struct *ret;
_

Patches currently in -mm which might be from hch@lst.de are

zsmalloc-switch-from-alloc_vm_area-to-get_vm_area.patch
mm-add-a-vmap_pfn-function.patch
drm-i915-use-vmap-in-shmem_pin_map.patch
drm-i915-use-vmap-in-i915_gem_object_map.patch
xen-xenbus-use-apply_to_page_range-directly-in-xenbus_map_ring_pv.patch
x86-xen-open-code-alloc_vm_area-in-arch_gnttab_valloc.patch