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authorMax Filippov <jcmvbkbc@gmail.com>2018-02-14 16:12:54 -0800
committerMax Filippov <jcmvbkbc@gmail.com>2018-07-11 11:13:33 -0700
commitadbfa4e6f99689511f1079452508d9d22417544c (patch)
treef4dc68dbca63090aa995105ac8a87f182eb8e05f /arch/xtensa/kernel/pci-dma.c
parent3f2bbf443e21584887f954328ceee8515d7691e7 (diff)
xtensa: support DMA_ATTR_NO_KERNEL_MAPPING attribute
An application that doesn't need kernel mapping of the DMA memory it allocates may specify DMA_ATTR_NO_KERNEL_MAPPING attribute to allocation function. Support this attribute and return address of the first struct page that covers the allocation. Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Diffstat (limited to 'arch/xtensa/kernel/pci-dma.c')
-rw-r--r--arch/xtensa/kernel/pci-dma.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c
index a83d60e92908..5c8a67fc3aa1 100644
--- a/arch/xtensa/kernel/pci-dma.c
+++ b/arch/xtensa/kernel/pci-dma.c
@@ -116,6 +116,10 @@ void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
*handle = phys_to_dma(dev, page_to_phys(page));
+ if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) {
+ return page;
+ }
+
#ifdef CONFIG_MMU
if (PageHighMem(page)) {
void *p;
@@ -147,8 +151,10 @@ void arch_dma_free(struct device *dev, size_t size, void *vaddr,
unsigned long addr = (unsigned long)vaddr;
struct page *page;
- if (addr >= XCHAL_KSEG_BYPASS_VADDR &&
- addr - XCHAL_KSEG_BYPASS_VADDR < XCHAL_KSEG_SIZE) {
+ if (attrs & DMA_ATTR_NO_KERNEL_MAPPING) {
+ page = vaddr;
+ } else if (addr >= XCHAL_KSEG_BYPASS_VADDR &&
+ addr - XCHAL_KSEG_BYPASS_VADDR < XCHAL_KSEG_SIZE) {
addr += XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;
page = virt_to_page(addr);
} else {