From: okaya@codeaurora•org (Sinan Kaya)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 2/3] swiotlb: prefix dma_to_phys and phys_to_dma functions
Date: Fri, 18 Mar 2016 11:00:21 -0400 [thread overview]
Message-ID: <56EC1805.5060207@codeaurora.org> (raw)
In-Reply-To: <56EBF09A.1060503@arm.com>
On 3/18/2016 8:12 AM, Robin Murphy wrote:
> Since we know for sure that swiotlb_to_phys is a no-op on arm64, it might be cleaner to simply not reference it at all. I suppose we could have some private local wrappers, e.g.:
>
> #define swiotlb_to_virt(addr) phys_to_virt((phys_addr_t)(addr))
>
> to keep the intent of the code clear (and just in case anyone ever builds a system mad enough to warrant switching out that definition, but I'd hope that never happens).
>
> Otherwise, looks good - thanks for doing this!
OK. I added this. Reviewed-by?
I'm not happy to submit such a big patch for all different ARCHs. I couldn't
find a cleaner solution. I'm willing to split this patch into multiple if there
is a better way.
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index ada00c3..8c0f66b 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -29,6 +29,14 @@
#include <asm/cacheflush.h>
+/*
+ * If you are building a system without IOMMU, then you are using SWIOTLB
+ * library. The ARM64 adaptation of this library does not support address
+ * translation and it assumes that physical address = dma address for such
+ * a use case. Please don't build a platform that violates this.
+ */
+#define swiotlb_to_virt(addr) phys_to_virt((phys_addr_t)(addr))
+
static pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot,
bool coherent)
{
@@ -188,7 +196,7 @@ static void __dma_free(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle,
struct dma_attrs *attrs)
{
- void *swiotlb_addr = phys_to_virt(swiotlb_dma_to_phys(dev, dma_handle));
+ void *swiotlb_addr = swiotlb_to_virt(dma_handle);
size = PAGE_ALIGN(size);
@@ -209,8 +217,7 @@ static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page,
dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs);
if (!is_device_dma_coherent(dev))
- __dma_map_area(phys_to_virt(swiotlb_dma_to_phys(dev, dev_addr)),
- size, dir);
+ __dma_map_area(swiotlb_to_virt(dev_addr), size, dir);
return dev_addr;
}
@@ -283,8 +290,7 @@ static void __swiotlb_sync_single_for_device(struct device *dev,
{
swiotlb_sync_single_for_device(dev, dev_addr, size, dir);
if (!is_device_dma_coherent(dev))
- __dma_map_area(phys_to_virt(swiotlb_dma_to_phys(dev, dev_addr)),
- size, dir);
+ __dma_map_area(swiotlb_to_virt(dev_addr), size, dir);
}
--
Sinan Kaya
Qualcomm Technologies, Inc. on behalf of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
next prev parent reply other threads:[~2016-03-18 15:00 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-17 22:02 [PATCH 1/3] crypto: marvell/cesa - replace dma_to_phys with dma_map_single Sinan Kaya
2016-03-17 22:02 ` [PATCH 2/3] swiotlb: prefix dma_to_phys and phys_to_dma functions Sinan Kaya
2016-03-18 12:12 ` Robin Murphy
2016-03-18 15:00 ` Sinan Kaya [this message]
2016-03-28 18:29 ` Konrad Rzeszutek Wilk
2016-03-29 12:44 ` Stefano Stabellini
2016-03-29 12:57 ` Sinan Kaya
2016-03-29 19:32 ` Arnd Bergmann
2016-03-17 22:02 ` [PATCH 3/3] dma-mapping: move swiotlb dma-phys functions to common header Sinan Kaya
2016-03-18 11:31 ` Robin Murphy
2016-03-18 13:55 ` Sinan Kaya
2016-03-17 22:54 ` [PATCH 1/3] crypto: marvell/cesa - replace dma_to_phys with dma_map_single Russell King - ARM Linux
2016-03-17 23:17 ` okaya at codeaurora.org
2016-03-17 23:50 ` Russell King - ARM Linux
2016-03-18 9:30 ` Boris Brezillon
2016-03-18 11:25 ` Robin Murphy
2016-03-18 11:32 ` Boris Brezillon
2016-03-18 13:51 ` Sinan Kaya
2016-03-18 14:00 ` Sinan Kaya
2016-03-18 14:20 ` Boris Brezillon
2016-03-18 14:21 ` Sinan Kaya
2016-03-18 20:18 ` kbuild test robot
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=56EC1805.5060207@codeaurora.org \
--to=okaya@codeaurora$(echo .)org \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox