Revert "mm/vmalloc: hugepage vmalloc mappings"

This reverts commit c353e29979762d1489a39ccc1d391726a28e3e26.

2 files changed, 28 insertions, 105 deletions

diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 4c92dc608928..812bea5866d6 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -42,7 +42,6 @@ struct vm_struct {
 	unsigned long		size;
 	unsigned long		flags;
 	struct page		**pages;
-	unsigned int		page_shift;
 	unsigned int		nr_pages;
 	phys_addr_t		phys_addr;
 	const void		*caller;
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 6370e0876a2c..5b9232e015fc 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -36,7 +36,6 @@
 #include <linux/rbtree_augmented.h>
 
 #include <linux/uaccess.h>
-#include <asm/pgtable.h>
 #include <asm/tlbflush.h>
 #include <asm/shmparam.h>
 
@@ -440,41 +439,6 @@ static int vmap_pages_range(unsigned long start, unsigned long end,
 	return ret;
 }
 
-#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
-static int vmap_hpages_range(unsigned long start, unsigned long end,
-				   pgprot_t prot, struct page **pages,
-				   unsigned int page_shift)
-{
-	unsigned long addr = start;
-	unsigned int i, nr = (end - start) >> (PAGE_SHIFT + page_shift);
-
-	for (i = 0; i < nr; i++) {
-		int err;
-
-		err = vmap_range_noflush(addr,
-					addr + (PAGE_SIZE << page_shift),
-					__pa(page_address(pages[i])), prot,
-					page_shift);
-		if (err)
-			return err;
-
-		addr += PAGE_SIZE << page_shift;
-	}
-	flush_cache_vmap(start, end);
-
-	return nr;
-}
-#else
-static int vmap_hpages_range(unsigned long start, unsigned long end,
-			   pgprot_t prot, struct page **pages,
-			   unsigned int page_shift)
-{
-	BUG_ON(page_shift != PAGE_SIZE);
-	return vmap_pages_range(start, end, prot, pages);
-}
-#endif
-
-
 int is_vmalloc_or_module_addr(const void *x)
 {
 	/*
@@ -497,7 +461,7 @@ struct page *vmalloc_to_page(const void *vmalloc_addr)
 {
 	unsigned long addr = (unsigned long) vmalloc_addr;
 	struct page *page = NULL;
-	pgd_t *pgd;
+	pgd_t *pgd = pgd_offset_k(addr);
 	p4d_t *p4d;
 	pud_t *pud;
 	pmd_t *pmd;
@@ -509,38 +473,27 @@ struct page *vmalloc_to_page(const void *vmalloc_addr)
 	 */
 	VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
 
-	pgd = pgd_offset_k(addr);
 	if (pgd_none(*pgd))
 		return NULL;
-
 	p4d = p4d_offset(pgd, addr);
 	if (p4d_none(*p4d))
 		return NULL;
-#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
-	if (p4d_large(*p4d))
-		return p4d_page(*p4d) + ((addr & ~P4D_MASK) >> PAGE_SHIFT);
-#endif
-	if (WARN_ON_ONCE(p4d_bad(*p4d)))
-		return NULL;
-
 	pud = pud_offset(p4d, addr);
-	if (pud_none(*pud))
-		return NULL;
-#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
-	if (pud_large(*pud))
-		return pud_page(*pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
-#endif
-	if (WARN_ON_ONCE(pud_bad(*pud)))
-		return NULL;
 
-	pmd = pmd_offset(pud, addr);
-	if (pmd_none(*pmd))
+	/*
+	 * Don't dereference bad PUD or PMD (below) entries. This will also
+	 * identify huge mappings, which we may encounter on architectures
+	 * that define CONFIG_HAVE_ARCH_HUGE_VMAP=y. Such regions will be
+	 * identified as vmalloc addresses by is_vmalloc_addr(), but are
+	 * not [unambiguously] associated with a struct page, so there is
+	 * no correct value to return for them.
+	 */
+	WARN_ON_ONCE(pud_bad(*pud));
+	if (pud_none(*pud) || pud_bad(*pud))
 		return NULL;
-#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
-	if (pmd_large(*pmd))
-		return pmd_page(*pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
-#endif
-	if (WARN_ON_ONCE(pmd_bad(*pmd)))
+	pmd = pmd_offset(pud, addr);
+	WARN_ON_ONCE(pmd_bad(*pmd));
+	if (pmd_none(*pmd) || pmd_bad(*pmd))
 		return NULL;
 
 	ptep = pte_offset_map(pmd, addr);
@@ -548,7 +501,6 @@ struct page *vmalloc_to_page(const void *vmalloc_addr)
 	if (pte_present(pte))
 		page = pte_page(pte);
 	pte_unmap(ptep);
-
 	return page;
 }
 EXPORT_SYMBOL(vmalloc_to_page);
@@ -2295,9 +2247,8 @@ static struct vm_struct *__get_vm_area_node(unsigned long size,
 		return NULL;
 
 	if (flags & VM_IOREMAP)
-		align = max(align,
-				1ul << clamp_t(int, get_count_order_long(size),
-				       PAGE_SHIFT, IOREMAP_MAX_ORDER));
+		align = 1ul << clamp_t(int, get_count_order_long(size),
+				       PAGE_SHIFT, IOREMAP_MAX_ORDER);
 
 	area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
 	if (unlikely(!area))
@@ -2509,7 +2460,7 @@ static void __vunmap(const void *addr, int deallocate_pages)
 			struct page *page = area->pages[i];
 
 			BUG_ON(!page);
-			__free_pages(page, area->page_shift);
+			__free_pages(page, 0);
 		}
 
 		kvfree(area->pages);
@@ -2652,17 +2603,14 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
 				 pgprot_t prot, int node)
 {
 	struct page **pages;
-	unsigned long addr = (unsigned long)area->addr;
-	unsigned long size = get_vm_area_size(area);
-	unsigned int page_shift = area->page_shift;
-	unsigned int shift = page_shift + PAGE_SHIFT;
 	unsigned int nr_pages, array_size, i;
 	const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
 	const gfp_t alloc_mask = gfp_mask | __GFP_NOWARN;
 	const gfp_t highmem_mask = (gfp_mask & (GFP_DMA | GFP_DMA32)) ?
-					0 : __GFP_HIGHMEM;
+					0 :
+					__GFP_HIGHMEM;
 
-	nr_pages = size >> shift;
+	nr_pages = get_vm_area_size(area) >> PAGE_SHIFT;
 	array_size = (nr_pages * sizeof(struct page *));
 
 	area->nr_pages = nr_pages;
@@ -2683,8 +2631,10 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
 	for (i = 0; i < area->nr_pages; i++) {
 		struct page *page;
 
-		page = alloc_pages_node(node,
-				alloc_mask|highmem_mask, page_shift);
+		if (node == NUMA_NO_NODE)
+			page = alloc_page(alloc_mask|highmem_mask);
+		else
+			page = alloc_pages_node(node, alloc_mask|highmem_mask, 0);
 
 		if (unlikely(!page)) {
 			/* Successfully allocated i pages, free them in __vunmap() */
@@ -2696,9 +2646,8 @@ static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
 			cond_resched();
 	}
 
-	if (vmap_hpages_range(addr, addr + size, prot, pages, page_shift) < 0)
+	if (map_vm_area(area, prot, pages))
 		goto fail;
-
 	return area->addr;
 
 fail:
@@ -2732,39 +2681,22 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align,
 			pgprot_t prot, unsigned long vm_flags, int node,
 			const void *caller)
 {
-	struct vm_struct *area = NULL;
+	struct vm_struct *area;
 	void *addr;
 	unsigned long real_size = size;
-	unsigned long real_align = align;
-	unsigned int shift = PAGE_SHIFT;
 
 	size = PAGE_ALIGN(size);
 	if (!size || (size >> PAGE_SHIFT) > totalram_pages())
 		goto fail;
 
-	if (IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP)) {
-		unsigned long size_per_node;
-
-		size_per_node = size;
-		if (node == NUMA_NO_NODE)
-			size_per_node /= num_online_nodes();
-		if (size_per_node >= PMD_SIZE)
-			shift = PMD_SHIFT;
-	}
-again:
-	align = max(real_align, 1UL << shift);
-	size = ALIGN(real_size, align);
-
 	area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED |
 				vm_flags, start, end, node, gfp_mask, caller);
 	if (!area)
 		goto fail;
 
-	area->page_shift = shift - PAGE_SHIFT;
-
 	addr = __vmalloc_area_node(area, gfp_mask, prot, node);
 	if (!addr)
-		goto fail;
+		return NULL;
 
 	/*
 	 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
@@ -2778,16 +2710,8 @@ again:
 	return addr;
 
 fail:
-	if (shift == PMD_SHIFT) {
-		shift = PAGE_SHIFT;
-		goto again;
-	}
-
-	if (!area) {
-		/* Warn for area allocation, page allocations already warn */
-		warn_alloc(gfp_mask, NULL,
+	warn_alloc(gfp_mask, NULL,
 			  "vmalloc: allocation failure: %lu bytes", real_size);
-	}
 	return NULL;
 }