This is rather overkill since currently all drivers call this from
hardirq (or at least timers). But maybe in the future we're going to
have thread irq handlers and what not, doesn't hurt to be prepared.
Plus this is an easy start for sprinkling these fence annotations into
shared code.
Cc: linux-media(a)vger.kernel.org
Cc: linaro-mm-sig(a)lists.linaro.org
Cc: linux-rdma(a)vger.kernel.org
Cc: amd-gfx(a)lists.freedesktop.org
Cc: intel-gfx(a)lists.freedesktop.org
Cc: Chris Wilson <chris(a)chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst(a)linux.intel.com>
Cc: Christian König <christian.koenig(a)amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter(a)intel.com>
---
drivers/gpu/drm/drm_vblank.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index 42a84eb4cc8c..d681ab09963c 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -24,6 +24,7 @@
* OTHER DEALINGS IN THE SOFTWARE.
*/
+#include <linux/dma-fence.h>
#include <linux/export.h>
#include <linux/moduleparam.h>
@@ -1909,7 +1910,7 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
{
struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
unsigned long irqflags;
- bool disable_irq;
+ bool disable_irq, fence_cookie;
if (drm_WARN_ON_ONCE(dev, !drm_dev_has_vblank(dev)))
return false;
@@ -1917,6 +1918,8 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
if (drm_WARN_ON(dev, pipe >= dev->num_crtcs))
return false;
+ fence_cookie = dma_fence_begin_signalling();
+
spin_lock_irqsave(&dev->event_lock, irqflags);
/* Need timestamp lock to prevent concurrent execution with
@@ -1929,6 +1932,7 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
if (!vblank->enabled) {
spin_unlock(&dev->vblank_time_lock);
spin_unlock_irqrestore(&dev->event_lock, irqflags);
+ dma_fence_end_signalling(fence_cookie);
return false;
}
@@ -1954,6 +1958,8 @@ bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe)
if (disable_irq)
vblank_disable_fn(&vblank->disable_timer);
+ dma_fence_end_signalling(fence_cookie);
+
return true;
}
EXPORT_SYMBOL(drm_handle_vblank);
--
2.27.0
From: Xiyu Yang <xiyuyang19(a)fudan.edu.cn>
[ Upstream commit 11425c4519e2c974a100fc984867046d905b9380 ]
ttm_bo_add_move_fence() invokes dma_fence_get(), which returns a
reference of the specified dma_fence object to "fence" with increased
refcnt.
When ttm_bo_add_move_fence() returns, local variable "fence" becomes
invalid, so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in one exception handling path of
ttm_bo_add_move_fence(). When no_wait_gpu flag is equals to true, the
function forgets to decrease the refcnt increased by dma_fence_get(),
causing a refcnt leak.
Fix this issue by calling dma_fence_put() when no_wait_gpu flag is
equals to true.
Signed-off-by: Xiyu Yang <xiyuyang19(a)fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf(a)gmail.com>
Reviewed-by: Christian König <christian.koenig(a)amd.com>
Link: https://patchwork.freedesktop.org/patch/370221/
Signed-off-by: Christian König <christian.koenig(a)amd.com>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
drivers/gpu/drm/ttm/ttm_bo.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index abf165b2f64fc..3ce8ad7603c7f 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -941,8 +941,10 @@ static int ttm_bo_add_move_fence(struct ttm_buffer_object *bo,
if (!fence)
return 0;
- if (no_wait_gpu)
+ if (no_wait_gpu) {
+ dma_fence_put(fence);
return -EBUSY;
+ }
dma_resv_add_shared_fence(bo->base.resv, fence);
--
2.25.1
From: Xiyu Yang <xiyuyang19(a)fudan.edu.cn>
[ Upstream commit 11425c4519e2c974a100fc984867046d905b9380 ]
ttm_bo_add_move_fence() invokes dma_fence_get(), which returns a
reference of the specified dma_fence object to "fence" with increased
refcnt.
When ttm_bo_add_move_fence() returns, local variable "fence" becomes
invalid, so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in one exception handling path of
ttm_bo_add_move_fence(). When no_wait_gpu flag is equals to true, the
function forgets to decrease the refcnt increased by dma_fence_get(),
causing a refcnt leak.
Fix this issue by calling dma_fence_put() when no_wait_gpu flag is
equals to true.
Signed-off-by: Xiyu Yang <xiyuyang19(a)fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf(a)gmail.com>
Reviewed-by: Christian König <christian.koenig(a)amd.com>
Link: https://patchwork.freedesktop.org/patch/370221/
Signed-off-by: Christian König <christian.koenig(a)amd.com>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
drivers/gpu/drm/ttm/ttm_bo.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 9e07c3f75156b..ef5bc00c73e23 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -881,8 +881,10 @@ static int ttm_bo_add_move_fence(struct ttm_buffer_object *bo,
if (!fence)
return 0;
- if (no_wait_gpu)
+ if (no_wait_gpu) {
+ dma_fence_put(fence);
return -EBUSY;
+ }
dma_resv_add_shared_fence(bo->base.resv, fence);
--
2.25.1
From: Xiyu Yang <xiyuyang19(a)fudan.edu.cn>
[ Upstream commit 37cc4b95d13f311c04aa8e9daacca3905ad45ca7 ]
ttm_bo_vm_fault_reserved() invokes dma_fence_get(), which returns a
reference of the specified dma_fence object to "moving" with increased
refcnt.
When ttm_bo_vm_fault_reserved() returns, local variable "moving" becomes
invalid, so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in several exception handling paths
of ttm_bo_vm_fault_reserved(). When those error scenarios occur such as
"err" equals to -EBUSY, the function forgets to decrease the refcnt
increased by dma_fence_get(), causing a refcnt leak.
Fix this issue by calling dma_fence_put() when no_wait_gpu flag is
equals to true.
Signed-off-by: Xiyu Yang <xiyuyang19(a)fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf(a)gmail.com>
Reviewed-by: Christian König <christian.koenig(a)amd.com>
Link: https://patchwork.freedesktop.org/patch/370219/
Signed-off-by: Christian König <christian.koenig(a)amd.com>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
drivers/gpu/drm/ttm/ttm_bo_vm.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index 0ad30b1129821..72100b84c7a90 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -300,8 +300,10 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf,
break;
case -EBUSY:
case -ERESTARTSYS:
+ dma_fence_put(moving);
return VM_FAULT_NOPAGE;
default:
+ dma_fence_put(moving);
return VM_FAULT_SIGBUS;
}
--
2.25.1
On 21.06.2020 06:00, Dmitry Osipenko wrote:
> В Fri, 19 Jun 2020 12:36:31 +0200
> Marek Szyprowski <m.szyprowski(a)samsung.com> пишет:
>
>> The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg()
>> function returns the number of the created entries in the DMA address
>> space. However the subsequent calls to the
>> dma_sync_sg_for_{device,cpu}() and dma_unmap_sg must be called with
>> the original number of the entries passed to the dma_map_sg().
>>
>> struct sg_table is a common structure used for describing a
>> non-contiguous memory buffer, used commonly in the DRM and graphics
>> subsystems. It consists of a scatterlist with memory pages and DMA
>> addresses (sgl entry), as well as the number of scatterlist entries:
>> CPU pages (orig_nents entry) and DMA mapped pages (nents entry).
>>
>> It turned out that it was a common mistake to misuse nents and
>> orig_nents entries, calling DMA-mapping functions with a wrong number
>> of entries or ignoring the number of mapped entries returned by the
>> dma_map_sg() function.
>>
>> To avoid such issues, lets use a common dma-mapping wrappers operating
>> directly on the struct sg_table objects and use scatterlist page
>> iterators where possible. This, almost always, hides references to the
>> nents and orig_nents entries, making the code robust, easier to follow
>> and copy/paste safe.
>>
>> Signed-off-by: Marek Szyprowski <m.szyprowski(a)samsung.com>
>> Reviewed-by: Dmitry Osipenko <digetx(a)gmail.com>
>> ---
>> drivers/staging/media/tegra-vde/iommu.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/staging/media/tegra-vde/iommu.c
>> b/drivers/staging/media/tegra-vde/iommu.c index
>> 6af863d92123..adf8dc7ee25c 100644 ---
>> a/drivers/staging/media/tegra-vde/iommu.c +++
>> b/drivers/staging/media/tegra-vde/iommu.c @@ -36,8 +36,8 @@ int
>> tegra_vde_iommu_map(struct tegra_vde *vde,
>> addr = iova_dma_addr(&vde->iova, iova);
>>
>> - size = iommu_map_sg(vde->domain, addr, sgt->sgl, sgt->nents,
>> - IOMMU_READ | IOMMU_WRITE);
>> + size = iommu_map_sgtable(vde->domain, addr, sgt,
>> + IOMMU_READ | IOMMU_WRITE);
>> if (!size) {
>> __free_iova(&vde->iova, iova);
>> return -ENXIO;
> Ahh, I saw the build failure report. You're changing the DMA API in
> this series, while DMA API isn't used by this driver, it uses IOMMU
> API. Hence there is no need to touch this code. Similar problem in the
> host1x driver patch.
The issue is caused by the lack of iommu_map_sgtable() stub when no
IOMMU support is configured. I've posted a patch for this:
https://lore.kernel.org/lkml/20200630081756.18526-1-m.szyprowski@samsung.co…
The patch for this driver is fine, we have to wait until the above fix
gets merged and then it can be applied during the next release cycle.
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
On Wed, May 20, 2020 at 03:39:31PM +0200, Erwan Le Ray wrote:
> Add support of generic DT binding for annoucing RTS/CTS lines. The initial
> binding 'st,hw-flow-control' is not needed anymore since generic binding
> is available, but is kept for backward compatibility.
>
> Signed-off-by: Erwan Le Ray <erwan.leray(a)st.com>
>
> diff --git a/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml b/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml
> index 75b8521eb7cb..06d5f251ec88 100644
> --- a/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml
> +++ b/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml
> @@ -35,9 +35,11 @@ properties:
> description: label associated with this uart
>
> st,hw-flow-ctrl:
> - description: enable hardware flow control
> + description: enable hardware flow control (deprecated)
> $ref: /schemas/types.yaml#/definitions/flag
>
> + uart-has-rtscts: true
> +
> dmas:
> minItems: 1
> maxItems: 2
> --
> 2.17.1
>
Did this get ignored by the DT maintainers? :(