From 5cf4537975bbd5691b9ddd015d540bb92f61e322 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 3 Jun 2019 09:14:31 +0200 Subject: dma-mapping: introduce a dma_common_find_pages helper A helper to find the backing page array based on a virtual address. This also ensures we do the same vm_flags check everywhere instead of slightly different or missing ones in a few places. Signed-off-by: Christoph Hellwig --- kernel/dma/remap.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'kernel/dma/remap.c') diff --git a/kernel/dma/remap.c b/kernel/dma/remap.c index f6b90521a7e4..ca4e5d44b571 100644 --- a/kernel/dma/remap.c +++ b/kernel/dma/remap.c @@ -11,6 +11,15 @@ #include #include +struct page **dma_common_find_pages(void *cpu_addr) +{ + struct vm_struct *area = find_vm_area(cpu_addr); + + if (!area || area->flags != VM_DMA_COHERENT) + return NULL; + return area->pages; +} + static struct vm_struct *__dma_common_pages_remap(struct page **pages, size_t size, pgprot_t prot, const void *caller) { @@ -78,9 +87,9 @@ void *dma_common_contiguous_remap(struct page *page, size_t size, */ void dma_common_free_remap(void *cpu_addr, size_t size) { - struct vm_struct *area = find_vm_area(cpu_addr); + struct page **pages = dma_common_find_pages(cpu_addr); - if (!area || area->flags != VM_DMA_COHERENT) { + if (!pages) { WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr); return; } -- cgit v1.2.3-58-ga151