[PATCH 3/3] drm/tegra: Implement correct DMA-BUF semantics
Thierry Reding
thierry.reding at gmail.com
Tue Dec 3 16:32:03 UTC 2019
From: Thierry Reding <treding at nvidia.com>
DMA-BUF requires that each device that accesses a DMA-BUF attaches to it
separately. To do so the host1x_bo_pin() and host1x_bo_unpin() functions
need to be reimplemented so that they can return a mapping, which either
represents an attachment or a map of the driver's own GEM object.
Signed-off-by: Thierry Reding <treding at nvidia.com>
---
drivers/gpu/drm/tegra/gem.c | 131 +++++++++++++++++++++-------------
drivers/gpu/drm/tegra/plane.c | 47 ++++--------
drivers/gpu/drm/tegra/plane.h | 2 +-
drivers/gpu/host1x/job.c | 127 ++++++++++++--------------------
drivers/gpu/host1x/job.h | 6 +-
include/linux/host1x.h | 32 ++++++---
6 files changed, 162 insertions(+), 183 deletions(-)
diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index 1237df157e05..c085499067ed 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -27,71 +27,77 @@ static void tegra_bo_put(struct host1x_bo *bo)
drm_gem_object_put_unlocked(&obj->gem);
}
-/* XXX move this into lib/scatterlist.c? */
-static int sg_alloc_table_from_sg(struct sg_table *sgt, struct scatterlist *sg,
- unsigned int nents, gfp_t gfp_mask)
+static struct host1x_bo_mapping *
+tegra_bo_pin(struct device *dev, struct host1x_bo *bo,
+ enum dma_data_direction direction)
{
- struct scatterlist *dst;
- unsigned int i;
+ struct tegra_bo *obj = host1x_to_tegra_bo(bo);
+ struct drm_gem_object *gem = &obj->gem;
+ struct host1x_bo_mapping *map;
int err;
- err = sg_alloc_table(sgt, nents, gfp_mask);
- if (err < 0)
- return err;
-
- dst = sgt->sgl;
+ map = kzalloc(sizeof(*map), GFP_KERNEL);
+ if (!map)
+ return ERR_PTR(-ENOMEM);
- for (i = 0; i < nents; i++) {
- sg_set_page(dst, sg_page(sg), sg->length, 0);
- dst = sg_next(dst);
- sg = sg_next(sg);
- }
-
- return 0;
-}
-
-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;
+ map->direction = direction;
+ map->dev = dev;
+ map->bo = bo;
/*
* If we've manually mapped the buffer object through the IOMMU, make
* sure to return the IOVA address of our mapping.
*/
- if (phys && obj->mm) {
- *phys = obj->iova;
- return NULL;
+ if (obj->mm) {
+ map->phys = obj->iova;
+ return map;
+ }
+
+ /*
+ * Imported buffers need special treatment to satisfy the semantics of
+ * DMA-BUF.
+ */
+ if (gem->import_attach) {
+ struct dma_buf *buf = gem->import_attach->dmabuf;
+
+ map->attach = dma_buf_attach(buf, dev);
+ if (IS_ERR(map->attach)) {
+ err = PTR_ERR(map->attach);
+ goto free;
+ }
+
+ map->sgt = dma_buf_map_attachment(map->attach, direction);
+ if (IS_ERR(map->sgt)) {
+ dma_buf_detach(buf, map->attach);
+ err = PTR_ERR(map->sgt);
+ goto free;
+ }
+
+ map->chunks = sgt_dma_count_chunks(map->sgt);
+ map->phys = sg_dma_address(map->sgt->sgl);
+ map->size = gem->size;
+
+ return map;
}
/*
* If we don't have a mapping for this buffer yet, return an SG table
* so that host1x can do the mapping for us via the DMA API.
*/
- sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
- if (!sgt)
- return ERR_PTR(-ENOMEM);
+ map->sgt = kzalloc(sizeof(*map->sgt), GFP_KERNEL);
+ if (!map->sgt) {
+ err = -ENOMEM;
+ goto free;
+ }
if (obj->pages) {
/*
* If the buffer object was allocated from the explicit IOMMU
* API code paths, construct an SG table from the 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 if (obj->sgt) {
- /*
- * If the buffer object already has an SG table but no pages
- * were allocated for it, it means the buffer was imported and
- * the SG table needs to be copied to avoid overwriting any
- * other potential users of the original SG table.
- */
- err = sg_alloc_table_from_sg(sgt, obj->sgt->sgl, obj->sgt->nents,
- GFP_KERNEL);
+ err = sg_alloc_table_from_pages(map->sgt, obj->pages,
+ obj->num_pages, 0,
+ obj->gem.size, GFP_KERNEL);
if (err < 0)
goto free;
} else {
@@ -100,25 +106,48 @@ static struct sg_table *tegra_bo_pin(struct device *dev, struct host1x_bo *bo,
* not imported, it had to be allocated with the DMA API, so
* the DMA API helper can be used.
*/
- err = dma_get_sgtable(dev, sgt, obj->vaddr, obj->iova,
+ err = dma_get_sgtable(dev, map->sgt, obj->vaddr, obj->iova,
obj->gem.size);
if (err < 0)
goto free;
}
- return sgt;
+ err = dma_map_sg(dev, map->sgt->sgl, map->sgt->nents, direction);
+ if (!err) {
+ err = -ENOMEM;
+ goto free_sgt;
+ }
+
+ map->phys = sg_dma_address(map->sgt->sgl);
+ map->size = gem->size;
+ map->chunks = err;
+
+ return map;
+free_sgt:
+ sg_free_table(map->sgt);
free:
- kfree(sgt);
+ kfree(map->sgt);
+ kfree(map);
return ERR_PTR(err);
}
-static void tegra_bo_unpin(struct device *dev, struct sg_table *sgt)
+static void tegra_bo_unpin(struct host1x_bo_mapping *map)
{
- if (sgt) {
- sg_free_table(sgt);
- kfree(sgt);
+ if (!map)
+ return;
+
+ if (map->attach) {
+ dma_buf_unmap_attachment(map->attach, map->sgt, map->direction);
+ dma_buf_detach(map->attach->dmabuf, map->attach);
+ } else {
+ dma_unmap_sg(map->dev, map->sgt->sgl, map->sgt->nents,
+ map->direction);
+ sg_free_table(map->sgt);
+ kfree(map->sgt);
}
+
+ kfree(map);
}
static void *tegra_bo_mmap(struct host1x_bo *bo)
diff --git a/drivers/gpu/drm/tegra/plane.c b/drivers/gpu/drm/tegra/plane.c
index cadcdd9ea427..28cf668026da 100644
--- a/drivers/gpu/drm/tegra/plane.c
+++ b/drivers/gpu/drm/tegra/plane.c
@@ -67,7 +67,7 @@ tegra_plane_atomic_duplicate_state(struct drm_plane *plane)
for (i = 0; i < 3; i++) {
copy->iova[i] = DMA_MAPPING_ERROR;
- copy->sgt[i] = NULL;
+ copy->map[i] = NULL;
}
return ©->base;
@@ -114,18 +114,11 @@ static int tegra_dc_pin(struct tegra_dc *dc, struct tegra_plane_state *state)
struct tegra_bo *bo = tegra_fb_get_plane(state->base.fb, i);
if (!dc->client.group) {
- struct sg_table *sgt;
+ struct host1x_bo_mapping *map;
- sgt = host1x_bo_pin(dc->dev, &bo->base, NULL);
- if (IS_ERR(sgt)) {
- err = PTR_ERR(sgt);
- goto unpin;
- }
-
- err = dma_map_sg(dc->dev, sgt->sgl, sgt->nents,
- DMA_TO_DEVICE);
- if (err == 0) {
- err = -ENOMEM;
+ map = host1x_bo_pin(dc->dev, &bo->base, DMA_TO_DEVICE);
+ if (IS_ERR(map)) {
+ err = PTR_ERR(map);
goto unpin;
}
@@ -135,13 +128,13 @@ static int tegra_dc_pin(struct tegra_dc *dc, struct tegra_plane_state *state)
* map its SG table to a single contiguous chunk of
* I/O virtual memory.
*/
- if (err > 1) {
+ if (map->chunks > 1) {
err = -EINVAL;
goto unpin;
}
- state->iova[i] = sg_dma_address(sgt->sgl);
- state->sgt[i] = sgt;
+ state->iova[i] = map->phys;
+ state->map[i] = map;
} else {
state->iova[i] = bo->iova;
}
@@ -153,14 +146,9 @@ static int tegra_dc_pin(struct tegra_dc *dc, struct tegra_plane_state *state)
dev_err(dc->dev, "failed to map plane %u: %d\n", i, err);
while (i--) {
- struct tegra_bo *bo = tegra_fb_get_plane(state->base.fb, i);
- struct sg_table *sgt = state->sgt[i];
-
- dma_unmap_sg(dc->dev, sgt->sgl, sgt->nents, DMA_TO_DEVICE);
- host1x_bo_unpin(dc->dev, &bo->base, sgt);
-
+ host1x_bo_unpin(state->map[i]);
state->iova[i] = DMA_MAPPING_ERROR;
- state->sgt[i] = NULL;
+ state->map[i] = NULL;
}
return err;
@@ -171,20 +159,11 @@ static void tegra_dc_unpin(struct tegra_dc *dc, struct tegra_plane_state *state)
unsigned int i;
for (i = 0; i < state->base.fb->format->num_planes; i++) {
- struct tegra_bo *bo = tegra_fb_get_plane(state->base.fb, i);
-
- if (!dc->client.group) {
- struct sg_table *sgt = state->sgt[i];
-
- if (sgt) {
- dma_unmap_sg(dc->dev, sgt->sgl, sgt->nents,
- DMA_TO_DEVICE);
- host1x_bo_unpin(dc->dev, &bo->base, sgt);
- }
- }
+ if (!dc->client.group)
+ host1x_bo_unpin(state->map[i]);
state->iova[i] = DMA_MAPPING_ERROR;
- state->sgt[i] = NULL;
+ state->map[i] = NULL;
}
}
diff --git a/drivers/gpu/drm/tegra/plane.h b/drivers/gpu/drm/tegra/plane.h
index a158a915109a..08df1ba1f567 100644
--- a/drivers/gpu/drm/tegra/plane.h
+++ b/drivers/gpu/drm/tegra/plane.h
@@ -39,7 +39,7 @@ struct tegra_plane_legacy_blending_state {
struct tegra_plane_state {
struct drm_plane_state base;
- struct sg_table *sgt[3];
+ struct host1x_bo_mapping *map[3];
dma_addr_t iova[3];
struct tegra_bo_tiling tiling;
diff --git a/drivers/gpu/host1x/job.c b/drivers/gpu/host1x/job.c
index 60b2fedd0061..88e445553df3 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)
{
+ unsigned long mask = HOST1X_RELOC_READ | HOST1X_RELOC_WRITE;
struct host1x_client *client = job->client;
struct device *dev = client->dev;
unsigned int i;
@@ -108,8 +109,8 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
for (i = 0; i < job->num_relocs; i++) {
struct host1x_reloc *reloc = &job->relocs[i];
- dma_addr_t phys_addr, *phys;
- struct sg_table *sgt;
+ enum dma_data_direction direction;
+ struct host1x_bo_mapping *map;
reloc->target.bo = host1x_bo_get(reloc->target.bo);
if (!reloc->target.bo) {
@@ -117,63 +118,40 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
goto unpin;
}
- if (client->group)
- phys = &phys_addr;
- else
- phys = NULL;
-
- sgt = host1x_bo_pin(dev, reloc->target.bo, phys);
- if (IS_ERR(sgt)) {
- err = PTR_ERR(sgt);
- goto unpin;
- }
-
- if (sgt) {
- unsigned long mask = HOST1X_RELOC_READ |
- HOST1X_RELOC_WRITE;
- enum dma_data_direction dir;
-
- switch (reloc->flags & mask) {
- case HOST1X_RELOC_READ:
- dir = DMA_TO_DEVICE;
- break;
-
- case HOST1X_RELOC_WRITE:
- dir = DMA_FROM_DEVICE;
- break;
+ switch (reloc->flags & mask) {
+ case HOST1X_RELOC_READ:
+ direction = DMA_TO_DEVICE;
+ break;
- case HOST1X_RELOC_READ | HOST1X_RELOC_WRITE:
- dir = DMA_BIDIRECTIONAL;
- break;
+ case HOST1X_RELOC_WRITE:
+ direction = DMA_FROM_DEVICE;
+ break;
- default:
- err = -EINVAL;
- goto unpin;
- }
+ case HOST1X_RELOC_READ | HOST1X_RELOC_WRITE:
+ direction = DMA_BIDIRECTIONAL;
+ break;
- err = dma_map_sg(dev, sgt->sgl, sgt->nents, dir);
- if (!err) {
- err = -ENOMEM;
- goto unpin;
- }
+ default:
+ err = -EINVAL;
+ goto unpin;
+ }
- job->unpins[job->num_unpins].dev = dev;
- job->unpins[job->num_unpins].dir = dir;
- phys_addr = sg_dma_address(sgt->sgl);
+ map = host1x_bo_pin(dev, reloc->target.bo, direction);
+ if (IS_ERR(map)) {
+ err = PTR_ERR(map);
+ goto unpin;
}
- job->addr_phys[job->num_unpins] = phys_addr;
- job->unpins[job->num_unpins].bo = reloc->target.bo;
- job->unpins[job->num_unpins].sgt = sgt;
+ job->addr_phys[job->num_unpins] = map->phys;
+ job->unpins[job->num_unpins].map = map;
job->num_unpins++;
}
for (i = 0; i < job->num_gathers; i++) {
struct host1x_job_gather *g = &job->gathers[i];
+ struct host1x_bo_mapping *map;
size_t gather_size = 0;
struct scatterlist *sg;
- struct sg_table *sgt;
- dma_addr_t phys_addr;
unsigned long shift;
struct iova *alloc;
unsigned int j;
@@ -184,15 +162,16 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
goto unpin;
}
- sgt = host1x_bo_pin(host->dev, g->bo, NULL);
- if (IS_ERR(sgt)) {
- err = PTR_ERR(sgt);
+ map = host1x_bo_pin(host->dev, g->bo, DMA_TO_DEVICE);
+ if (IS_ERR(map)) {
+ err = PTR_ERR(map);
goto unpin;
}
if (!IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL) && host->domain) {
- for_each_sg(sgt->sgl, sg, sgt->nents, j)
+ for_each_sg(map->sgt->sgl, sg, map->sgt->nents, j)
gather_size += sg->length;
+
gather_size = iova_align(&host->iova, gather_size);
shift = iova_shift(&host->iova);
@@ -204,35 +183,24 @@ static unsigned int pin_job(struct host1x *host, struct host1x_job *job)
}
err = iommu_map_sg(host->domain,
- iova_dma_addr(&host->iova, alloc),
- sgt->sgl, sgt->nents, IOMMU_READ);
+ iova_dma_addr(&host->iova, alloc),
+ map->sgt->sgl, map->sgt->nents,
+ IOMMU_READ);
if (err == 0) {
__free_iova(&host->iova, alloc);
err = -EINVAL;
goto unpin;
}
- job->unpins[job->num_unpins].size = gather_size;
- phys_addr = iova_dma_addr(&host->iova, alloc);
- } else {
- err = dma_map_sg(host->dev, sgt->sgl, sgt->nents,
- DMA_TO_DEVICE);
- if (!err) {
- err = -ENOMEM;
- goto unpin;
- }
-
- job->unpins[job->num_unpins].dev = host->dev;
- phys_addr = sg_dma_address(sgt->sgl);
+ map->phys = iova_dma_addr(&host->iova, alloc);
+ map->size = gather_size;
}
- job->addr_phys[job->num_unpins] = phys_addr;
- job->gather_addr_phys[i] = phys_addr;
-
- job->unpins[job->num_unpins].dir = DMA_TO_DEVICE;
- job->unpins[job->num_unpins].bo = g->bo;
- job->unpins[job->num_unpins].sgt = sgt;
+ job->addr_phys[job->num_unpins] = map->phys;
+ job->unpins[job->num_unpins].map = map;
job->num_unpins++;
+
+ job->gather_addr_phys[i] = map->phys;
}
return 0;
@@ -608,24 +576,19 @@ void host1x_job_unpin(struct host1x_job *job)
unsigned int i;
for (i = 0; i < job->num_unpins; i++) {
- struct host1x_job_unpin_data *unpin = &job->unpins[i];
- struct device *dev = unpin->dev ?: host->dev;
- struct sg_table *sgt = unpin->sgt;
+ struct host1x_bo_mapping *map = job->unpins[i].map;
+ struct host1x_bo *bo = map->bo;
if (!IS_ENABLED(CONFIG_TEGRA_HOST1X_FIREWALL) &&
- unpin->size && host->domain) {
+ map->size && host->domain) {
iommu_unmap(host->domain, job->addr_phys[i],
- unpin->size);
+ map->size);
free_iova(&host->iova,
- iova_pfn(&host->iova, job->addr_phys[i]));
+ iova_pfn(&host->iova, job->addr_phys[i]));
}
- if (unpin->dev && sgt)
- dma_unmap_sg(unpin->dev, sgt->sgl, sgt->nents,
- unpin->dir);
-
- host1x_bo_unpin(dev, unpin->bo, sgt);
- host1x_bo_put(unpin->bo);
+ host1x_bo_unpin(map);
+ host1x_bo_put(bo);
}
job->num_unpins = 0;
diff --git a/drivers/gpu/host1x/job.h b/drivers/gpu/host1x/job.h
index 94bc2e4ae241..c28eebb8ce14 100644
--- a/drivers/gpu/host1x/job.h
+++ b/drivers/gpu/host1x/job.h
@@ -19,11 +19,7 @@ struct host1x_job_gather {
};
struct host1x_job_unpin_data {
- struct host1x_bo *bo;
- struct sg_table *sgt;
- struct device *dev;
- size_t size;
- enum dma_data_direction dir;
+ struct host1x_bo_mapping *map;
};
/*
diff --git a/include/linux/host1x.h b/include/linux/host1x.h
index 0254ebcdc0a7..f1e6fad19289 100644
--- a/include/linux/host1x.h
+++ b/include/linux/host1x.h
@@ -7,6 +7,7 @@
#define __LINUX_HOST1X_H
#include <linux/device.h>
+#include <linux/dma-direction.h>
#include <linux/types.h>
enum host1x_class {
@@ -72,12 +73,24 @@ struct host1x_client {
struct host1x_bo;
struct sg_table;
+struct host1x_bo_mapping {
+ struct dma_buf_attachment *attach;
+ enum dma_data_direction direction;
+ struct host1x_bo *bo;
+ struct sg_table *sgt;
+ unsigned int chunks;
+ struct device *dev;
+ dma_addr_t phys;
+ size_t size;
+};
+
struct host1x_bo_ops {
struct host1x_bo *(*get)(struct host1x_bo *bo);
void (*put)(struct host1x_bo *bo);
- struct sg_table *(*pin)(struct device *dev, struct host1x_bo *bo,
- dma_addr_t *phys);
- void (*unpin)(struct device *dev, struct sg_table *sgt);
+ struct host1x_bo_mapping *(*pin)(struct device *dev,
+ struct host1x_bo *bo,
+ enum dma_data_direction dir);
+ void (*unpin)(struct host1x_bo_mapping *map);
void *(*mmap)(struct host1x_bo *bo);
void (*munmap)(struct host1x_bo *bo, void *addr);
};
@@ -102,17 +115,16 @@ static inline void host1x_bo_put(struct host1x_bo *bo)
bo->ops->put(bo);
}
-static inline struct sg_table *host1x_bo_pin(struct device *dev,
- struct host1x_bo *bo,
- dma_addr_t *phys)
+static inline struct host1x_bo_mapping *
+host1x_bo_pin(struct device *dev, struct host1x_bo *bo,
+ enum dma_data_direction dir)
{
- return bo->ops->pin(dev, bo, phys);
+ return bo->ops->pin(dev, bo, dir);
}
-static inline void host1x_bo_unpin(struct device *dev, struct host1x_bo *bo,
- struct sg_table *sgt)
+static inline void host1x_bo_unpin(struct host1x_bo_mapping *map)
{
- bo->ops->unpin(dev, sgt);
+ map->bo->ops->unpin(map);
}
static inline void *host1x_bo_mmap(struct host1x_bo *bo)
--
2.23.0
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