On Wed, 30 Sep 2020 18:09:13 Christoph Hellwig wrote:
>
> Prepare for supporting the DMA_ATTR_NO_KERNEL_MAPPING flag in
> dma_alloc_pages.
>
> Signed-off-by: Christoph Hellwig <h...@lst.de>
> ---
> kernel/dma/direct.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
> index b5f20781d3a96f..b5d56810130b22 100644
> --- a/kernel/dma/direct.c
> +++ b/kernel/dma/direct.c
> @@ -296,9 +296,10 @@ struct page *dma_direct_alloc_pages(struct device *dev,
> size_t size,
> dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
> {
> struct page *page;
> - void *ret;
>
> if (dma_should_alloc_from_pool(dev, gfp, 0)) {
> + void *ret;
> +
> page = dma_alloc_from_pool(dev, size, &ret, gfp,
> dma_coherent_ok);
> if (!page)
> @@ -306,7 +307,7 @@ struct page *dma_direct_alloc_pages(struct device *dev,
> size_t size,
> goto done;
> }
>
> - page = __dma_direct_alloc_pages(dev, size, gfp);
> + page = __dma_direct_alloc_pages(dev, size, gfp | __GFP_ZERO);
> if (!page)
> return NULL;
> if (PageHighMem(page)) {
> @@ -320,13 +321,11 @@ struct page *dma_direct_alloc_pages(struct device *dev,
> size_t size,
> goto out_free_pages;
> }
>
> - ret = page_address(page);
> if (force_dma_unencrypted(dev)) {
> - if (set_memory_decrypted((unsigned long)ret,
> + if (set_memory_decrypted((unsigned long)page_address(page),
> 1 << get_order(size)))
> goto out_free_pages;
> }
> - memset(ret, 0, size);
Not sure this works without changes in cma_alloc().
> done:
> *dma_handle = phys_to_dma_direct(dev, page_to_phys(page));
> return page;
> --
> 2.28.0
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