diff options
Diffstat (limited to 'drivers/base')
-rw-r--r-- | drivers/base/dma-mapping.c | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c index 6cd08e1..9e8bbdd 100644 --- a/drivers/base/dma-mapping.c +++ b/drivers/base/dma-mapping.c @@ -10,6 +10,8 @@ #include <linux/dma-mapping.h> #include <linux/export.h> #include <linux/gfp.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> #include <asm-generic/dma-coherent.h> /* @@ -267,3 +269,73 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma, return ret; } EXPORT_SYMBOL(dma_common_mmap); + +#ifdef CONFIG_MMU +/* + * remaps an array of PAGE_SIZE pages into another vm_area + * Cannot be used in non-sleeping contexts + */ +void *dma_common_pages_remap(struct page **pages, size_t size, + unsigned long vm_flags, pgprot_t prot, + const void *caller) +{ + struct vm_struct *area; + + area = get_vm_area_caller(size, vm_flags, caller); + if (!area) + return NULL; + + area->pages = pages; + + if (map_vm_area(area, prot, pages)) { + vunmap(area->addr); + return NULL; + } + + return area->addr; +} + +/* + * remaps an allocated contiguous region into another vm_area. + * Cannot be used in non-sleeping contexts + */ + +void *dma_common_contiguous_remap(struct page *page, size_t size, + unsigned long vm_flags, + pgprot_t prot, const void *caller) +{ + int i; + struct page **pages; + void *ptr; + unsigned long pfn; + + pages = kmalloc(sizeof(struct page *) << get_order(size), GFP_KERNEL); + if (!pages) + return NULL; + + for (i = 0, pfn = page_to_pfn(page); i < (size >> PAGE_SHIFT); i++) + pages[i] = pfn_to_page(pfn + i); + + ptr = dma_common_pages_remap(pages, size, vm_flags, prot, caller); + + kfree(pages); + + return ptr; +} + +/* + * unmaps a range previously mapped by dma_common_*_remap + */ +void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags) +{ + struct vm_struct *area = find_vm_area(cpu_addr); + + if (!area || (area->flags & vm_flags) != vm_flags) { + WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr); + return; + } + + unmap_kernel_range((unsigned long)cpu_addr, size); + vunmap(cpu_addr); +} +#endif |