From: Christoph Hellwig <hch@lst.de>
To: Will Deacon <will.deacon@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Robin Murphy <robin.murphy@arm.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: linux-arm-kernel@lists.infradead.org,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Subject: [PATCH 8/9] swiotlb: add support for non-coherent DMA
Date: Mon, 17 Sep 2018 17:38:25 +0200 [thread overview]
Message-ID: <20180917153826.28052-9-hch@lst.de> (raw)
In-Reply-To: <20180917153826.28052-1-hch@lst.de>
Handle architectures that are not cache coherent directly in the main
swiotlb code. This involves two related changes:
- call arch_sync_dma_for_{device,cpu} in all the right places from the
various dma_map/unmap/sync methods when the device is non-coherent
- call arch_dma_{alloc,free} for devices that are non-coherent
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/arm64/mm/dma-mapping.c | 6 ++---
include/linux/swiotlb.h | 4 ++--
kernel/dma/swiotlb.c | 44 ++++++++++++++++++++++++++++++-------
3 files changed, 41 insertions(+), 13 deletions(-)
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index abcae73eea50..07d9c2633f80 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -112,7 +112,7 @@ static void *__dma_alloc(struct device *dev, size_t size,
return addr;
}
- ptr = swiotlb_alloc(dev, size, dma_handle, flags, attrs);
+ ptr = __swiotlb_alloc(dev, size, dma_handle, flags, attrs);
if (!ptr)
goto no_mem;
@@ -133,7 +133,7 @@ static void *__dma_alloc(struct device *dev, size_t size,
return coherent_ptr;
no_map:
- swiotlb_free(dev, size, ptr, *dma_handle, attrs);
+ __swiotlb_free(dev, size, ptr, *dma_handle, attrs);
no_mem:
return NULL;
}
@@ -151,7 +151,7 @@ static void __dma_free(struct device *dev, size_t size,
return;
vunmap(vaddr);
}
- swiotlb_free(dev, size, swiotlb_addr, dma_handle, attrs);
+ __swiotlb_free(dev, size, swiotlb_addr, dma_handle, attrs);
}
static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page,
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index f847c1b265c4..bc809d826d4f 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -67,9 +67,9 @@ extern void swiotlb_tbl_sync_single(struct device *hwdev,
/* Accessory functions. */
-void *swiotlb_alloc(struct device *hwdev, size_t size, dma_addr_t *dma_handle,
+void *__swiotlb_alloc(struct device *hwdev, size_t size, dma_addr_t *dma_handle,
gfp_t flags, unsigned long attrs);
-void swiotlb_free(struct device *dev, size_t size, void *vaddr,
+void __swiotlb_free(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_addr, unsigned long attrs);
extern dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 4d7a4d85d71e..83e597101c6a 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -21,6 +21,7 @@
#include <linux/cache.h>
#include <linux/dma-direct.h>
+#include <linux/dma-noncoherent.h>
#include <linux/mm.h>
#include <linux/export.h>
#include <linux/spinlock.h>
@@ -749,6 +750,10 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
dma_addr = swiotlb_bounce_page(dev, &phys, size, dir, attrs);
}
+ if (!dev_is_dma_coherent(dev) &&
+ (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
+ arch_sync_dma_for_device(dev, phys, size, dir);
+
return dma_addr;
}
@@ -768,6 +773,10 @@ void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
BUG_ON(dir == DMA_NONE);
+ if (!dev_is_dma_coherent(hwdev) &&
+ (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
+ arch_sync_dma_for_cpu(hwdev, paddr, size, dir);
+
if (is_swiotlb_buffer(paddr)) {
swiotlb_tbl_unmap_single(hwdev, paddr, size, dir, attrs);
return;
@@ -804,15 +813,17 @@ swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
BUG_ON(dir == DMA_NONE);
- if (is_swiotlb_buffer(paddr)) {
+ if (!dev_is_dma_coherent(hwdev) && target == SYNC_FOR_CPU)
+ arch_sync_dma_for_cpu(hwdev, paddr, size, dir);
+
+ if (is_swiotlb_buffer(paddr))
swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target);
- return;
- }
- if (dir != DMA_FROM_DEVICE)
- return;
+ if (!dev_is_dma_coherent(hwdev) && target == SYNC_FOR_DEVICE)
+ arch_sync_dma_for_device(hwdev, paddr, size, dir);
- dma_mark_clean(phys_to_virt(paddr), size);
+ if (!is_swiotlb_buffer(paddr) && dir == DMA_FROM_DEVICE)
+ dma_mark_clean(phys_to_virt(paddr), size);
}
void
@@ -928,7 +939,7 @@ swiotlb_dma_supported(struct device *hwdev, u64 mask)
return __phys_to_dma(hwdev, io_tlb_end - 1) <= mask;
}
-void *swiotlb_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
+void *__swiotlb_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
gfp_t gfp, unsigned long attrs)
{
void *vaddr;
@@ -950,13 +961,30 @@ void *swiotlb_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
return vaddr;
}
-void swiotlb_free(struct device *dev, size_t size, void *vaddr,
+static void *swiotlb_alloc(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
+{
+ if (!dev_is_dma_coherent(dev))
+ return arch_dma_alloc(dev, size, dma_handle, gfp, attrs);
+ return __swiotlb_alloc(dev, size, dma_handle, gfp, attrs);
+}
+
+void __swiotlb_free(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_addr, unsigned long attrs)
{
if (!swiotlb_free_buffer(dev, size, dma_addr))
dma_direct_free(dev, size, vaddr, dma_addr, attrs);
}
+static void swiotlb_free(struct device *dev, size_t size, void *vaddr,
+ dma_addr_t dma_addr, unsigned long attrs)
+{
+ if (!dev_is_dma_coherent(dev))
+ arch_dma_free(dev, size, vaddr, dma_addr, attrs);
+ else
+ __swiotlb_free(dev, size, vaddr, dma_addr, attrs);
+}
+
const struct dma_map_ops swiotlb_dma_ops = {
.mapping_error = dma_direct_mapping_error,
.alloc = swiotlb_alloc,
--
2.18.0
next prev parent reply other threads:[~2018-09-17 15:39 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-17 15:38 move swiotlb noncoherent dma support from arm64 to generic code Christoph Hellwig
2018-09-17 15:38 ` [PATCH 1/9] swiotlb: remove a pointless comment Christoph Hellwig
2018-09-17 15:38 ` [PATCH 2/9] swiotlb: mark is_swiotlb_buffer static Christoph Hellwig
2018-09-17 15:38 ` [PATCH 3/9] swiotlb: do not panic on mapping failures Christoph Hellwig
2018-09-17 15:38 ` [PATCH 4/9] swiotlb: remove the overflow buffer Christoph Hellwig
2018-09-17 15:38 ` [PATCH 5/9] swiotlb: merge swiotlb_unmap_page and unmap_single Christoph Hellwig
2018-09-17 15:38 ` [PATCH 6/9] swiotlb: use swiotlb_map_page in swiotlb_map_sg_attrs Christoph Hellwig
2018-09-17 15:38 ` [PATCH 7/9] swiotlb: refactor swiotlb_map_page Christoph Hellwig
2018-09-17 15:38 ` Christoph Hellwig [this message]
2018-09-17 15:38 ` [PATCH 9/9] arm64: use the generic swiotlb_dma_ops Christoph Hellwig
2018-09-18 13:28 ` move swiotlb noncoherent dma support from arm64 to generic code Robin Murphy
2018-09-18 16:11 ` Christoph Hellwig
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