From: Thierry Reding treding@nvidia.com
The host1x_bo_pin() and host1x_bo_unpin() APIs are used to pin and unpin buffers during host1x job submission. Pinning currently returns the SG table and the DMA address (an IOVA if an IOMMU is used or a physical address if no IOMMU is used) of the buffer. The DMA address is only used for buffers that are relocated, whereas the host1x driver will map gather buffers into its own IOVA space so that they can be processed by the CDMA engine.
This approach has a couple of issues. On one hand it's not very useful to return a DMA address for the buffer if host1x doesn't need it. On the other hand, returning the SG table of the buffer is suboptimal because a single SG table cannot be shared for multiple mappings, because the DMA address is stored within the SG table, and the DMA address may be different for different devices.
Subsequent patches will move the host1x driver over to the DMA API which doesn't work with a single shared SG table. Fix this by returning a new SG table each time a buffer is pinned. This allows the buffer to be referenced by multiple jobs for different engines.
Change the prototypes of host1x_bo_pin() and host1x_bo_unpin() to take a struct device *, specifying the device for which the buffer should be pinned. This is required in order to be able to properly construct the SG table. While at it, make host1x_bo_pin() return the SG table because that allows us to return an ERR_PTR()-encoded error code if we need to, or return NULL to signal that we don't need the SG table to be remapped and can simply use the DMA address as-is. At the same time, returning the DMA address is made optional because in the example of command buffers, host1x doesn't need to know the DMA address since it will have to create its own mapping anyway.
Signed-off-by: Thierry Reding treding@nvidia.com --- drivers/gpu/drm/tegra/gem.c | 34 ++++++++++++++++++++++++++++++---- drivers/gpu/host1x/job.c | 15 ++++++++++++--- include/linux/host1x.h | 17 ++++++++++------- 3 files changed, 52 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c index d2f88cc3134f..564ef60f67c2 100644 --- a/drivers/gpu/drm/tegra/gem.c +++ b/drivers/gpu/drm/tegra/gem.c @@ -27,17 +27,43 @@ static void tegra_bo_put(struct host1x_bo *bo) drm_gem_object_put_unlocked(&obj->gem); }
-static dma_addr_t tegra_bo_pin(struct host1x_bo *bo, struct sg_table **sgt) +static struct sg_table *tegra_bo_pin(struct device *dev, struct host1x_bo *bo, + dma_addr_t *phys) { struct tegra_bo *obj = host1x_to_tegra_bo(bo); + struct sg_table *sgt; + int err; + + if (phys) + *phys = obj->iova;
- *sgt = obj->sgt; + sgt = kzalloc(sizeof(*sgt), GFP_KERNEL); + if (!sgt) + return ERR_PTR(-ENOMEM);
- return obj->iova; + if (obj->pages) { + err = sg_alloc_table_from_pages(sgt, obj->pages, obj->num_pages, + 0, obj->gem.size, GFP_KERNEL); + if (err < 0) + goto free; + } else { + err = dma_get_sgtable(dev, sgt, obj->vaddr, obj->iova, + obj->gem.size); + if (err < 0) + goto free; + } + + return sgt; + +free: + kfree(sgt); + return ERR_PTR(err); }
-static void tegra_bo_unpin(struct host1x_bo *bo, struct sg_table *sgt) +static void tegra_bo_unpin(struct device *dev, struct sg_table *sgt) { + sg_free_table(sgt); + kfree(sgt); }
static void *tegra_bo_mmap(struct host1x_bo *bo) diff --git a/drivers/gpu/host1x/job.c b/drivers/gpu/host1x/job.c index eaa5c3352c13..90dd592fdfca 100644 --- a/drivers/gpu/host1x/job.c +++ b/drivers/gpu/host1x/job.c @@ -99,6 +99,7 @@ EXPORT_SYMBOL(host1x_job_add_gather);
static unsigned int pin_job(struct host1x *host, struct host1x_job *job) { + struct device *dev = job->client->dev; unsigned int i; int err;
@@ -115,7 +116,11 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job) goto unpin; }
- phys_addr = host1x_bo_pin(reloc->target.bo, &sgt); + sgt = host1x_bo_pin(dev, reloc->target.bo, &phys_addr); + if (IS_ERR(sgt)) { + err = PTR_ERR(sgt); + goto unpin; + }
job->addr_phys[job->num_unpins] = phys_addr; job->unpins[job->num_unpins].bo = reloc->target.bo; @@ -139,7 +144,11 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job) goto unpin; }
- phys_addr = host1x_bo_pin(g->bo, &sgt); + sgt = host1x_bo_pin(host->dev, g->bo, &phys_addr); + if (IS_ERR(sgt)) { + err = PTR_ERR(sgt); + goto unpin; + }
if (!IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL) && host->domain) { for_each_sg(sgt->sgl, sg, sgt->nents, j) @@ -566,7 +575,7 @@ void host1x_job_unpin(struct host1x_job *job) iova_pfn(&host->iova, job->addr_phys[i])); }
- host1x_bo_unpin(unpin->bo, unpin->sgt); + host1x_bo_unpin(host->dev, unpin->bo, unpin->sgt); host1x_bo_put(unpin->bo); }
diff --git a/include/linux/host1x.h b/include/linux/host1x.h index df6e613ba715..1ba23a6a2021 100644 --- a/include/linux/host1x.h +++ b/include/linux/host1x.h @@ -67,8 +67,9 @@ struct sg_table; struct host1x_bo_ops { struct host1x_bo *(*get)(struct host1x_bo *bo); void (*put)(struct host1x_bo *bo); - dma_addr_t (*pin)(struct host1x_bo *bo, struct sg_table **sgt); - void (*unpin)(struct host1x_bo *bo, struct sg_table *sgt); + struct sg_table *(*pin)(struct device *dev, struct host1x_bo *bo, + dma_addr_t *phys); + void (*unpin)(struct device *dev, struct sg_table *sgt); void *(*mmap)(struct host1x_bo *bo); void (*munmap)(struct host1x_bo *bo, void *addr); void *(*kmap)(struct host1x_bo *bo, unsigned int pagenum); @@ -95,15 +96,17 @@ static inline void host1x_bo_put(struct host1x_bo *bo) bo->ops->put(bo); }
-static inline dma_addr_t host1x_bo_pin(struct host1x_bo *bo, - struct sg_table **sgt) +static inline struct sg_table *host1x_bo_pin(struct device *dev, + struct host1x_bo *bo, + dma_addr_t *phys) { - return bo->ops->pin(bo, sgt); + return bo->ops->pin(dev, bo, phys); }
-static inline void host1x_bo_unpin(struct host1x_bo *bo, struct sg_table *sgt) +static inline void host1x_bo_unpin(struct device *dev, struct host1x_bo *bo, + struct sg_table *sgt) { - bo->ops->unpin(bo, sgt); + bo->ops->unpin(dev, sgt); }
static inline void *host1x_bo_mmap(struct host1x_bo *bo)