Commit 6137e416 authored by Max Filippov's avatar Max Filippov

xtensa: support DMA buffers in high memory

If a DMA buffer is allocated in high memory and kernel mapping is
required use dma_common_contiguous_remap to map buffer to the vmalloc
region and dma_common_free_remap to unmap it.
Signed-off-by: default avatarMax Filippov <jcmvbkbc@gmail.com>
parent 6ac5a11d
...@@ -16,6 +16,7 @@ ...@@ -16,6 +16,7 @@
*/ */
#include <linux/dma-contiguous.h> #include <linux/dma-contiguous.h>
#include <linux/dma-direct.h>
#include <linux/gfp.h> #include <linux/gfp.h>
#include <linux/highmem.h> #include <linux/highmem.h>
#include <linux/mm.h> #include <linux/mm.h>
...@@ -123,7 +124,7 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size, ...@@ -123,7 +124,7 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size,
unsigned long attrs) unsigned long attrs)
{ {
unsigned long ret; unsigned long ret;
unsigned long uncached = 0; unsigned long uncached;
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
struct page *page = NULL; struct page *page = NULL;
...@@ -144,15 +145,27 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size, ...@@ -144,15 +145,27 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size,
if (!page) if (!page)
return NULL; return NULL;
ret = (unsigned long)page_address(page); *handle = phys_to_dma(dev, page_to_phys(page));
/* We currently don't support coherent memory outside KSEG */ #ifdef CONFIG_MMU
if (PageHighMem(page)) {
void *p;
p = dma_common_contiguous_remap(page, size, VM_MAP,
pgprot_noncached(PAGE_KERNEL),
__builtin_return_address(0));
if (!p) {
if (!dma_release_from_contiguous(dev, page, count))
__free_pages(page, get_order(size));
}
return p;
}
#endif
ret = (unsigned long)page_address(page);
BUG_ON(ret < XCHAL_KSEG_CACHED_VADDR || BUG_ON(ret < XCHAL_KSEG_CACHED_VADDR ||
ret > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1); ret > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1);
uncached = ret + XCHAL_KSEG_BYPASS_VADDR - XCHAL_KSEG_CACHED_VADDR; uncached = ret + XCHAL_KSEG_BYPASS_VADDR - XCHAL_KSEG_CACHED_VADDR;
*handle = virt_to_bus((void *)ret);
__invalidate_dcache_range(ret, size); __invalidate_dcache_range(ret, size);
return (void *)uncached; return (void *)uncached;
...@@ -161,13 +174,20 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size, ...@@ -161,13 +174,20 @@ static void *xtensa_dma_alloc(struct device *dev, size_t size,
static void xtensa_dma_free(struct device *dev, size_t size, void *vaddr, static void xtensa_dma_free(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle, unsigned long attrs) dma_addr_t dma_handle, unsigned long attrs)
{ {
unsigned long addr = (unsigned long)vaddr +
XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR;
struct page *page = virt_to_page(addr);
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned long addr = (unsigned long)vaddr;
BUG_ON(addr < XCHAL_KSEG_CACHED_VADDR || struct page *page;
addr > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1);
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 {
#ifdef CONFIG_MMU
dma_common_free_remap(vaddr, size, VM_MAP);
#endif
page = pfn_to_page(PHYS_PFN(dma_to_phys(dev, dma_handle)));
}
if (!dma_release_from_contiguous(dev, page, count)) if (!dma_release_from_contiguous(dev, page, count))
__free_pages(page, get_order(size)); __free_pages(page, get_order(size));
......
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