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

From: Ricardo Ribalda <ribalda@chromium.org>
To: Christoph Hellwig <hch@lst.de>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	IOMMU DRIVERS <iommu@lists.linux-foundation.org>,
	Joerg Roedel <joro@8bytes.org>,
	Robin Murphy <robin.murphy@arm.com>,
	Linux Doc Mailing List <linux-doc@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Linux Media Mailing List <linux-media@vger.kernel.org>,
	Tomasz Figa <tfiga@chromium.org>,
	Sergey Senozhatsky <senozhatsky@google.com>
Subject: [PATCH 2/6] dma-direct: use __GFP_ZERO in dma_direct_alloc_pages
Date: Tue, 24 Nov 2020 16:38:41 +0100	[thread overview]
Message-ID: <20201124153845.132207-2-ribalda@chromium.org> (raw)
In-Reply-To: <20201124153845.132207-1-ribalda@chromium.org>

From: Christoph Hellwig <hch@lst.de>

Prepare for supporting the DMA_ATTR_NO_KERNEL_MAPPING flag in
dma_alloc_pages.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 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

