diff options
Diffstat (limited to 'mm/vmalloc.c')
-rw-r--r-- | mm/vmalloc.c | 72 |
1 files changed, 65 insertions, 7 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index d3a9c5368257..3130c343088f 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -68,12 +68,12 @@ static inline void vunmap_pud_range(pgd_t *pgd, unsigned long addr, } while (pud++, addr = next, addr != end); } -void unmap_vm_area(struct vm_struct *area) +void unmap_kernel_range(unsigned long addr, unsigned long size) { pgd_t *pgd; unsigned long next; - unsigned long addr = (unsigned long) area->addr; - unsigned long end = addr + area->size; + unsigned long start = addr; + unsigned long end = addr + size; BUG_ON(addr >= end); pgd = pgd_offset_k(addr); @@ -84,7 +84,12 @@ void unmap_vm_area(struct vm_struct *area) continue; vunmap_pud_range(pgd, addr, next); } while (pgd++, addr = next, addr != end); - flush_tlb_kernel_range((unsigned long) area->addr, end); + flush_tlb_kernel_range(start, end); +} + +static void unmap_vm_area(struct vm_struct *area) +{ + unmap_kernel_range((unsigned long)area->addr, area->size); } static int vmap_pte_range(pmd_t *pmd, unsigned long addr, @@ -427,11 +432,12 @@ void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, area->nr_pages = nr_pages; /* Please note that the recursion is strictly bounded. */ if (array_size > PAGE_SIZE) { - pages = __vmalloc_node(array_size, gfp_mask, PAGE_KERNEL, node); + pages = __vmalloc_node(array_size, gfp_mask | __GFP_ZERO, + PAGE_KERNEL, node); area->flags |= VM_VPAGES; } else { pages = kmalloc_node(array_size, - (gfp_mask & GFP_LEVEL_MASK), + (gfp_mask & GFP_LEVEL_MASK) | __GFP_ZERO, node); } area->pages = pages; @@ -440,7 +446,6 @@ void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, kfree(area); return NULL; } - memset(area->pages, 0, array_size); for (i = 0; i < area->nr_pages; i++) { if (node < 0) @@ -762,3 +767,56 @@ EXPORT_SYMBOL(remap_vmalloc_range); void __attribute__((weak)) vmalloc_sync_all(void) { } + + +static int f(pte_t *pte, struct page *pmd_page, unsigned long addr, void *data) +{ + /* apply_to_page_range() does all the hard work. */ + return 0; +} + +/** + * alloc_vm_area - allocate a range of kernel address space + * @size: size of the area + * @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 the kernel address space is not shared + * between processes, it syncs the pagetable across all + * processes. + */ +struct vm_struct *alloc_vm_area(size_t size) +{ + struct vm_struct *area; + + area = get_vm_area(size, VM_IOREMAP); + 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, + area->size, f, NULL)) { + free_vm_area(area); + return NULL; + } + + /* Make sure the pagetables are constructed in process kernel + mappings */ + vmalloc_sync_all(); + + return area; +} +EXPORT_SYMBOL_GPL(alloc_vm_area); + +void free_vm_area(struct vm_struct *area) +{ + struct vm_struct *ret; + ret = remove_vm_area(area->addr); + BUG_ON(ret != area); + kfree(area); +} +EXPORT_SYMBOL_GPL(free_vm_area); |