@@ -170,11 +170,9 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
goto unpin;
}
- err = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
- if (!err) {
- err = -ENOMEM;
+ err = dma_map_sgtable(dev, sgt, dir, 0);
+ if (err)
goto unpin;
- }
job->unpins[job->num_unpins].dev = dev;
job->unpins[job->num_unpins].dir = dir;
@@ -228,7 +226,7 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
}
if (host->domain) {
- for_each_sg(sgt->sgl, sg, sgt->nents, j)
+ for_each_sgtable_sg(sgt, sg, j)
gather_size += sg->length;
gather_size = iova_align(&host->iova, gather_size);
@@ -240,9 +238,9 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
goto put;
}
- err = iommu_map_sg(host->domain,
+ err = iommu_map_sgtable(host->domain,
iova_dma_addr(&host->iova, alloc),
- sgt->sgl, sgt->nents, IOMMU_READ);
+ sgt, IOMMU_READ);
if (err == 0) {
__free_iova(&host->iova, alloc);
err = -EINVAL;
@@ -252,12 +250,9 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
job->unpins[job->num_unpins].size = gather_size;
phys_addr = iova_dma_addr(&host->iova, alloc);
} else if (sgt) {
- err = dma_map_sg(host->dev, sgt->sgl, sgt->nents,
- DMA_TO_DEVICE);
- if (!err) {
- err = -ENOMEM;
+ err = dma_map_sgtable(host->dev, sgt, DMA_TO_DEVICE, 0);
+ if (err)
goto put;
- }
job->unpins[job->num_unpins].dir = DMA_TO_DEVICE;
job->unpins[job->num_unpins].dev = host->dev;
@@ -660,8 +655,7 @@ void host1x_job_unpin(struct host1x_job *job)
}
if (unpin->dev && sgt)
- dma_unmap_sg(unpin->dev, sgt->sgl, sgt->nents,
- unpin->dir);
+ dma_unmap_sgtable(unpin->dev, sgt, unpin->dir, 0);
host1x_bo_unpin(dev, unpin->bo, sgt);
host1x_bo_put(unpin->bo);
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@samsung.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com> --- drivers/gpu/host1x/job.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-)