From 7641842164c34b672ef3e70e881e8a72735305c1 Mon Sep 17 00:00:00 2001
From: Alexander Duyck <alexander.h.duyck@intel.com>
Date: Wed, 2 Nov 2016 07:12:47 -0400
Subject: swiotlb-xen: Enforce return of DMA_ERROR_CODE in mapping function
The mapping function should always return DMA_ERROR_CODE when a mapping has
failed as this is what the DMA API expects when a DMA error has occurred.
The current function for mapping a page in Xen was returning either
DMA_ERROR_CODE or 0 depending on where it failed.
On x86 DMA_ERROR_CODE is 0, but on other architectures such as ARM it is
~0. We need to make sure we return the same error value if either the
mapping failed or the device is not capable of accessing the mapping.
If we are returning DMA_ERROR_CODE as our error value we can drop the
function for checking the error code as the default is to compare the
return value against DMA_ERROR_CODE if no function is defined.
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>
---
drivers/xen/swiotlb-xen.c | 18 ++++++------------
1 file changed, 6 insertions(+), 12 deletions(-)
(limited to 'drivers/xen')
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 87e6035c9e81..b8014bf2b2ed 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -416,11 +416,12 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
/*
* Ensure that the address returned is DMA'ble
*/
- if (!dma_capable(dev, dev_addr, size)) {
- swiotlb_tbl_unmap_single(dev, map, size, dir);
- dev_addr = 0;
- }
- return dev_addr;
+ if (dma_capable(dev, dev_addr, size))
+ return dev_addr;
+
+ swiotlb_tbl_unmap_single(dev, map, size, dir);
+
+ return DMA_ERROR_CODE;
}
EXPORT_SYMBOL_GPL(xen_swiotlb_map_page);
@@ -648,13 +649,6 @@ xen_swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
}
EXPORT_SYMBOL_GPL(xen_swiotlb_sync_sg_for_device);
-int
-xen_swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
-{
- return !dma_addr;
-}
-EXPORT_SYMBOL_GPL(xen_swiotlb_dma_mapping_error);
-
/*
* Return whether the given device DMA address mask can be supported
* properly. For example, if your device can only drive the low 24-bits
--
cgit v1.2.3
From 0443fa003fa199f41bfbed3012f314d02c5b1f24 Mon Sep 17 00:00:00 2001
From: Alexander Duyck <alexander.h.duyck@intel.com>
Date: Wed, 2 Nov 2016 07:13:02 -0400
Subject: swiotlb: Add support for DMA_ATTR_SKIP_CPU_SYNC
As a first step to making DMA_ATTR_SKIP_CPU_SYNC apply to architectures
beyond just ARM I need to make it so that the swiotlb will respect the
flag. In order to do that I also need to update the swiotlb-xen since it
heavily makes use of the functionality.
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>
---
drivers/xen/swiotlb-xen.c | 11 +++++----
include/linux/swiotlb.h | 6 +++--
lib/swiotlb.c | 59 ++++++++++++++++++++++++++++++-----------------
3 files changed, 49 insertions(+), 27 deletions(-)
(limited to 'drivers/xen')
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index b8014bf2b2ed..3d048afcee38 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -405,7 +405,8 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
*/
trace_swiotlb_bounced(dev, dev_addr, size, swiotlb_force);
- map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir);
+ map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir,
+ attrs);
if (map == SWIOTLB_MAP_ERROR)
return DMA_ERROR_CODE;
@@ -419,7 +420,8 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
if (dma_capable(dev, dev_addr, size))
return dev_addr;
- swiotlb_tbl_unmap_single(dev, map, size, dir);
+ swiotlb_tbl_unmap_single(dev, map, size, dir,
+ attrs | DMA_ATTR_SKIP_CPU_SYNC);
return DMA_ERROR_CODE;
}
@@ -445,7 +447,7 @@ static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr,
/* NOTE: We use dev_addr here, not paddr! */
if (is_xen_swiotlb_buffer(dev_addr)) {
- swiotlb_tbl_unmap_single(hwdev, paddr, size, dir);
+ swiotlb_tbl_unmap_single(hwdev, paddr, size, dir, attrs);
return;
}
@@ -558,11 +560,12 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
start_dma_addr,
sg_phys(sg),
sg->length,
- dir);
+ dir, attrs);
if (map == SWIOTLB_MAP_ERROR) {
dev_warn(hwdev, "swiotlb buffer is full\n");
/* Don't panic here, we expect map_sg users
to do proper error handling. */
+ attrs |= DMA_ATTR_SKIP_CPU_SYNC;
xen_swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
attrs);
sg_dma_len(sgl) = 0;
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index f0d258967869..183f37c8a5e1 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -44,11 +44,13 @@ enum dma_sync_target {
extern phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
dma_addr_t tbl_dma_addr,
phys_addr_t phys, size_t size,
- enum dma_data_direction dir);
+ enum dma_data_direction dir,
+ unsigned long attrs);
extern void swiotlb_tbl_unmap_single(struct device *hwdev,
phys_addr_t tlb_addr,
- size_t size, enum dma_data_direction dir);
+ size_t size, enum dma_data_direction dir,
+ unsigned long attrs);
extern void swiotlb_tbl_sync_single(struct device *hwdev,
phys_addr_t tlb_addr,
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index bdcc0d8a7405..8e883c762728 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -425,7 +425,8 @@ static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr,
phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
dma_addr_t tbl_dma_addr,
phys_addr_t orig_addr, size_t size,
- enum dma_data_direction dir)
+ enum dma_data_direction dir,
+ unsigned long attrs)
{
unsigned long flags;
phys_addr_t tlb_addr;
@@ -526,7 +527,8 @@ found:
*/
for (i = 0; i < nslots; i++)
io_tlb_orig_addr[index+i] = orig_addr + (i << IO_TLB_SHIFT);
- if (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
+ (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL))
swiotlb_bounce(orig_addr, tlb_addr, size, DMA_TO_DEVICE);
return tlb_addr;
@@ -539,18 +541,20 @@ EXPORT_SYMBOL_GPL(swiotlb_tbl_map_single);
static phys_addr_t
map_single(struct device *hwdev, phys_addr_t phys, size_t size,
- enum dma_data_direction dir)
+ enum dma_data_direction dir, unsigned long attrs)
{
dma_addr_t start_dma_addr = phys_to_dma(hwdev, io_tlb_start);
- return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size, dir);
+ return swiotlb_tbl_map_single(hwdev, start_dma_addr, phys, size,
+ dir, attrs);
}
/*
* dma_addr is the kernel virtual address of the bounce buffer to unmap.
*/
void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr,
- size_t size, enum dma_data_direction dir)
+ size_t size, enum dma_data_direction dir,
+ unsigned long attrs)
{
unsigned long flags;
int i, count, nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
@@ -561,6 +565,7 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr,
* First, sync the memory before unmapping the entry
*/
if (orig_addr != INVALID_PHYS_ADDR &&
+ !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
((dir == DMA_FROM_DEVICE) || (dir == DMA_BIDIRECTIONAL)))
swiotlb_bounce(orig_addr, tlb_addr, size, DMA_FROM_DEVICE);
@@ -654,7 +659,8 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
* GFP_DMA memory; fall back on map_single(), which
* will grab memory from the lowest available address range.
*/
- phys_addr_t paddr = map_single(hwdev, 0, size, DMA_FROM_DEVICE);
+ phys_addr_t paddr = map_single(hwdev, 0, size,
+ DMA_FROM_DEVICE, 0);
if (paddr == SWIOTLB_MAP_ERROR)
goto err_warn;
@@ -667,9 +673,13 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
(unsigned long long)dma_mask,
(unsigned long long)dev_addr);
- /* DMA_TO_DEVICE to avoid memcpy in unmap_single */
+ /*
+ * DMA_TO_DEVICE to avoid memcpy in unmap_single.
+ * The DMA_ATTR_SKIP_CPU_SYNC is optional.
+ */
swiotlb_tbl_unmap_single(hwdev, paddr,
- size, DMA_TO_DEVICE);
+ size, DMA_TO_DEVICE,
+ DMA_ATTR_SKIP_CPU_SYNC);
goto err_warn;
}
}
@@ -698,8 +708,12 @@ swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
if (!is_swiotlb_buffer(paddr))
free_pages((unsigned long)vaddr, get_order(size));
else
- /* DMA_TO_DEVICE to avoid memcpy in swiotlb_tbl_unmap_single */
- swiotlb_tbl_unmap_single(hwdev, paddr, size, DMA_TO_DEVICE);
+ /*
+ * DMA_TO_DEVICE to avoid memcpy in swiotlb_tbl_unmap_single.
+ * DMA_ATTR_SKIP_CPU_SYNC is optional.
+ */
+ swiotlb_tbl_unmap_single(hwdev, paddr, size, DMA_TO_DEVICE,
+ DMA_ATTR_SKIP_CPU_SYNC);
}
EXPORT_SYMBOL(swiotlb_free_coherent);
@@ -755,7 +769,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
trace_swiotlb_bounced(dev, dev_addr, size, swiotlb_force);
/* Oh well, have to allocate and map a bounce buffer. */
- map = map_single(dev, phys, size, dir);
+ map = map_single(dev, phys, size, dir, attrs);
if (map == SWIOTLB_MAP_ERROR) {
swiotlb_full(dev, size, dir, 1);
return phys_to_dma(dev, io_tlb_overflow_buffer);
@@ -764,12 +778,13 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
dev_addr = phys_to_dma(dev, map);
/* Ensure that the address returned is DMA'ble */
- if (!dma_capable(dev, dev_addr, size)) {
- swiotlb_tbl_unmap_single(dev, map, size, dir);
- return phys_to_dma(dev, io_tlb_overflow_buffer);
- }
+ if (dma_capable(dev, dev_addr, size))
+ return dev_addr;
+
+ swiotlb_tbl_unmap_single(dev, map, size, dir,
+ attrs | DMA_ATTR_SKIP_CPU_SYNC);
- return dev_addr;
+ return phys_to_dma(dev, io_tlb_overflow_buffer);
}
EXPORT_SYMBOL_GPL(swiotlb_map_page);
@@ -782,14 +797,15 @@ EXPORT_SYMBOL_GPL(swiotlb_map_page);
* whatever the device wrote there.
*/
static void unmap_single(struct device *hwdev, dma_addr_t dev_addr,
- size_t size, enum dma_data_direction dir)
+ size_t size, enum dma_data_direction dir,
+ unsigned long attrs)
{
phys_addr_t paddr = dma_to_phys(hwdev, dev_addr);
BUG_ON(dir == DMA_NONE);
if (is_swiotlb_buffer(paddr)) {
- swiotlb_tbl_unmap_single(hwdev, paddr, size, dir);
+ swiotlb_tbl_unmap_single(hwdev, paddr, size, dir, attrs);
return;
}
@@ -809,7 +825,7 @@ void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
size_t size, enum dma_data_direction dir,
unsigned long attrs)
{
- unmap_single(hwdev, dev_addr, size, dir);
+ unmap_single(hwdev, dev_addr, size, dir, attrs);
}
EXPORT_SYMBOL_GPL(swiotlb_unmap_page);
@@ -891,7 +907,7 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
if (swiotlb_force ||
!dma_capable(hwdev, dev_addr, sg->length)) {
phys_addr_t map = map_single(hwdev, sg_phys(sg),
- sg->length, dir);
+ sg->length, dir, attrs);
if (map == SWIOTLB_MAP_ERROR) {
/* Don't panic here, we expect map_sg users
to do proper error handling. */
@@ -925,7 +941,8 @@ swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
BUG_ON(dir == DMA_NONE);
for_each_sg(sgl, sg, nelems, i)
- unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir);
+ unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir,
+ attrs);
}
EXPORT_SYMBOL(swiotlb_unmap_sg_attrs);
--
cgit v1.2.3
From d29fa0cb7602fa3e96c9eee05e14d14d3e823c89 Mon Sep 17 00:00:00 2001
From: Alexander Duyck <alexander.h.duyck@intel.com>
Date: Thu, 10 Nov 2016 07:05:31 -0500
Subject: swiotlb: Minor fix-ups for DMA_ATTR_SKIP_CPU_SYNC support
I am updating the paths so that instead of trying to pass
"attr | DMA_ATTR_SKIP_CPU_SYNC" we instead just OR the value into attr and
then pass it since attr will not be used after we make the unmap call.
I realized there was one spot I had missed when I was applying the DMA
attribute to the DMA mapping exception handling. This change corrects that.
Finally it looks like there is a stray blank line at the end of the
swiotlb_unmap_sg_attrs function that can be dropped.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>
---
drivers/xen/swiotlb-xen.c | 4 ++--
lib/swiotlb.c | 6 +++---
2 files changed, 5 insertions(+), 5 deletions(-)
(limited to 'drivers/xen')
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 3d048afcee38..478fb91e3df2 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -420,8 +420,8 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
if (dma_capable(dev, dev_addr, size))
return dev_addr;
- swiotlb_tbl_unmap_single(dev, map, size, dir,
- attrs | DMA_ATTR_SKIP_CPU_SYNC);
+ attrs |= DMA_ATTR_SKIP_CPU_SYNC;
+ swiotlb_tbl_unmap_single(dev, map, size, dir, attrs);
return DMA_ERROR_CODE;
}
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 8e883c762728..cb1b54ee8527 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -781,8 +781,8 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
if (dma_capable(dev, dev_addr, size))
return dev_addr;
- swiotlb_tbl_unmap_single(dev, map, size, dir,
- attrs | DMA_ATTR_SKIP_CPU_SYNC);
+ attrs |= DMA_ATTR_SKIP_CPU_SYNC;
+ swiotlb_tbl_unmap_single(dev, map, size, dir, attrs);
return phys_to_dma(dev, io_tlb_overflow_buffer);
}
@@ -912,6 +912,7 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
/* Don't panic here, we expect map_sg users
to do proper error handling. */
swiotlb_full(hwdev, sg->length, dir, 0);
+ attrs |= DMA_ATTR_SKIP_CPU_SYNC;
swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
attrs);
sg_dma_len(sgl) = 0;
@@ -943,7 +944,6 @@ swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
for_each_sg(sgl, sg, nelems, i)
unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir,
attrs);
-
}
EXPORT_SYMBOL(swiotlb_unmap_sg_attrs);
--
cgit v1.2.3