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dma-direct: clean up the remapping checks in dma_direct_alloc

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Add two local variables to track if we want to remap the returned
address using vmap or call dma_set_uncached and use that to simplify
the code flow.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
This commit is contained in:
Christoph Hellwig 2021-11-09 15:20:40 +01:00
parent a90cf30437
commit f3c962226d
1 changed files with 26 additions and 22 deletions
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48
kernel/dma/direct.c
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@ -171,6 +171,7 @@ static void *dma_direct_alloc_from_pool(struct device *dev, size_t size,
void *dma_direct_alloc(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
bool remap = false, set_uncached = false;
struct page *page;
void *ret;
@ -222,9 +223,25 @@ void *dma_direct_alloc(struct device *dev, size_t size,
if (!page)
return NULL;
if ((IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&
!dev_is_dma_coherent(dev)) ||
(IS_ENABLED(CONFIG_DMA_REMAP) && PageHighMem(page))) {
if (!dev_is_dma_coherent(dev) && IS_ENABLED(CONFIG_DMA_DIRECT_REMAP)) {
remap = true;
} else if (PageHighMem(page)) {
/*
* Depending on the cma= arguments and per-arch setup,
* dma_alloc_contiguous could return highmem pages.
* Without remapping there is no way to return them here, so
* log an error and fail.
*/
if (!IS_ENABLED(CONFIG_DMA_REMAP)) {
dev_info(dev, "Rejecting highmem page from CMA.\n");
goto out_free_pages;
}
remap = true;
} else if (!dev_is_dma_coherent(dev) &&
IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED))
set_uncached = true;
if (remap) {
/* remove any dirty cache lines on the kernel alias */
arch_dma_prep_coherent(page, size);
@ -234,34 +251,21 @@ void *dma_direct_alloc(struct device *dev, size_t size,
__builtin_return_address(0));
if (!ret)
goto out_free_pages;
memset(ret, 0, size);
goto done;
} else {
ret = page_address(page);
if (dma_set_decrypted(dev, ret, size))
goto out_free_pages;
}
if (PageHighMem(page)) {
/*
* Depending on the cma= arguments and per-arch setup
* dma_alloc_contiguous could return highmem pages.
* Without remapping there is no way to return them here,
* so log an error and fail.
*/
dev_info(dev, "Rejecting highmem page from CMA.\n");
goto out_free_pages;
}
ret = page_address(page);
if (dma_set_decrypted(dev, ret, size))
goto out_free_pages;
memset(ret, 0, size);
if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) &&
!dev_is_dma_coherent(dev)) {
if (set_uncached) {
arch_dma_prep_coherent(page, size);
ret = arch_dma_set_uncached(ret, size);
if (IS_ERR(ret))
goto out_encrypt_pages;
}
done:
*dma_handle = phys_to_dma_direct(dev, page_to_phys(page));
return ret;