[PATCH 4.19 100/219] gpu: host1x: Allocate gather copy for host1x

Greg Kroah-Hartman
2019-12-29T17:31:38Z

From: Thierry Reding <treding@nvidia.com>

[ Upstream commit b78e70c04c149299bd210759d7c7af7c86b89ca8 ]

Currently when the gather buffers are copied, they are copied to a
buffer that is allocated for the host1x client that wants to execute the
command streams in the buffers. However, the gather buffers will be read
by the host1x device, which causes SMMU faults if the DMA API is backed
by an IOMMU.

Fix this by allocating the gather buffer copy for the host1x device,
which makes sure that it will be mapped into the host1x's IOVA space if
the DMA API is backed by an IOMMU.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/host1x/job.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/host1x/job.c b/drivers/gpu/host1x/job.c
index 527a1cddb14f..916b2355e11a 100644
--- a/drivers/gpu/host1x/job.c
+++ b/drivers/gpu/host1x/job.c
@@ -447,7 +447,8 @@ out:
return err;
}

-static inline int copy_gathers(struct host1x_job *job, struct device *dev)
+static inline int copy_gathers(struct device *host, struct host1x_job *job,
+ struct device *dev)
{
struct host1x_firewall fw;
size_t size = 0;
@@ -470,12 +471,12 @@ static inline int copy_gathers(struct host1x_job *job, struct device *dev)
* Try a non-blocking allocation from a higher priority pools first,
* as awaiting for the allocation here is a major performance hit.
*/
- job->gather_copy_mapped = dma_alloc_wc(dev, size, &job->gather_copy,
+ job->gather_copy_mapped = dma_alloc_wc(host, size, &job->gather_copy,
GFP_NOWAIT);

/* the higher priority allocation failed, try the generic-blocking */
if (!job->gather_copy_mapped)
- job->gather_copy_mapped = dma_alloc_wc(dev, size,
+ job->gather_copy_mapped = dma_alloc_wc(host, size,
&job->gather_copy,
GFP_KERNEL);
if (!job->gather_copy_mapped)
@@ -523,7 +524,7 @@ int host1x_job_pin(struct host1x_job *job, struct device *dev)
goto out;

if (IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL)) {
- err = copy_gathers(job, dev);
+ err = copy_gathers(host->dev, job, dev);
if (err)
goto out;
}
@@ -584,7 +585,7 @@ void host1x_job_unpin(struct host1x_job *job)
job->num_unpins = 0;

if (job->gather_copy_size)
- dma_free_wc(job->channel->dev, job->gather_copy_size,
+ dma_free_wc(host->dev, job->gather_copy_size,
job->gather_copy_mapped, job->gather_copy);
}
EXPORT_SYMBOL(host1x_job_unpin);
--
2.20.1