2020-11-24 15:41:51

by Ricardo Ribalda

Subject: [PATCH 2/6] dma-direct: use __GFP_ZERO in dma_direct_alloc_pages

From: Christoph Hellwig <[email protected]>

Prepare for supporting the DMA_ATTR_NO_KERNEL_MAPPING flag in
dma_alloc_pages.

Signed-off-by: Christoph Hellwig <[email protected]>
---
kernel/dma/direct.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 06c111544f61..76c741e610fc 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -280,13 +280,12 @@ 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 (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&
force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp))
return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);

- 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)) {
@@ -300,13 +299,11 @@ 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);
*dma_handle = phys_to_dma_direct(dev, page_to_phys(page));
return page;
out_free_pages:
--
2.29.2.454.gaff20da3a2-goog

2020-11-30 08:31:18

by Christoph Hellwig

Subject: Re: [PATCH 2/6] dma-direct: use __GFP_ZERO in dma_direct_alloc_pages

On Tue, Nov 24, 2020 at 04:38:41PM +0100, Ricardo Ribalda wrote:
> From: Christoph Hellwig <[email protected]>
>
> Prepare for supporting the DMA_ATTR_NO_KERNEL_MAPPING flag in
> dma_alloc_pages.
>
> Signed-off-by: Christoph Hellwig <[email protected]>

FYI, this patch should be dropped as I've implemented the functionality
differently.