| Message ID | 1449268039-24682-16-git-send-email-laurent.pinchart@ideasonboard.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sat, Dec 05, 2015 at 12:27:19AM +0200, Laurent Pinchart wrote: > OMAP GEM objects backed by dma_buf reuse the current OMAP GEM object > support as much as possible. If the imported buffer is physically > contiguous its physical address will be used directly, reusing the > OMAP_BO_MEM_DMA_API code paths. Otherwise it will be mapped through the > TILER using a pages list created from the scatterlist instead of the > shmem backing storage. > > Disallow exporting imported buffers for now as those code paths haven't > been verified. Use cases of such a feature are suspicious anyway. If you export a buffer that's been imported the drm_prime.c helpers should dig out the original dma-buf again. You should never end up with a dma-buf -> omap gem bo -> dma-buf chain. If that doesn't work then there's a bug somewhere ... -Daniel > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > --- > drivers/gpu/drm/omapdrm/omap_drv.h | 2 + > drivers/gpu/drm/omapdrm/omap_gem.c | 138 ++++++++++++++++++++++++------ > drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 57 +++++++++--- > 3 files changed, 163 insertions(+), 34 deletions(-) > > diff --git a/drivers/gpu/drm/omapdrm/omap_drv.h b/drivers/gpu/drm/omapdrm/omap_drv.h > index 97fcb892fdd7..6615b7d51ee3 100644 > --- a/drivers/gpu/drm/omapdrm/omap_drv.h > +++ b/drivers/gpu/drm/omapdrm/omap_drv.h > @@ -200,6 +200,8 @@ void omap_gem_deinit(struct drm_device *dev); > > struct drm_gem_object *omap_gem_new(struct drm_device *dev, > union omap_gem_size gsize, uint32_t flags); > +struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size, > + struct sg_table *sgt); > int omap_gem_new_handle(struct drm_device *dev, struct drm_file *file, > union omap_gem_size gsize, uint32_t flags, uint32_t *handle); > void omap_gem_free_object(struct drm_gem_object *obj); > diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c > index 11df4f78d8a7..8a54d333a47b 100644 > --- a/drivers/gpu/drm/omapdrm/omap_gem.c > +++ b/drivers/gpu/drm/omapdrm/omap_gem.c > @@ -33,6 +33,7 @@ > #define OMAP_BO_MEM_DMA_API 0x01000000 /* memory allocated with the dma_alloc_* API */ > #define OMAP_BO_MEM_SHMEM 0x02000000 /* memory allocated through shmem backing */ > #define OMAP_BO_MEM_EXT 0x04000000 /* memory allocated externally */ > +#define OMAP_BO_MEM_DMABUF 0x08000000 /* memory imported from a dmabuf */ > #define OMAP_BO_EXT_SYNC 0x10000000 /* externally allocated sync object */ > > struct omap_gem_object { > @@ -49,17 +50,25 @@ struct omap_gem_object { > uint32_t roll; > > /** > - * If buffer is allocated physically contiguous, the OMAP_BO_MEM_DMA_API > - * flag is set and the paddr is valid. Also if the buffer is remapped > - * in TILER and paddr_cnt > 0, then paddr is valid. But if you are using > - * the physical address and OMAP_BO_MEM_DMA_API is not set, then you > - * should be going thru omap_gem_{get,put}_paddr() to ensure the mapping > - * is not removed from under your feet. > + * paddr contains the buffer DMA address. It is valid for > * > - * Note that OMAP_BO_SCANOUT is a hint from userspace that DMA capable > - * buffer is requested, but doesn't mean that it is. Use the > - * OMAP_BO_MEM_DMA_API flag to determine if the buffer has a DMA capable > - * physical address. > + * - buffers allocated through the DMA mapping API (with the > + * OMAP_BO_MEM_DMA_API flag set) > + * > + * - buffers imported from dmabuf (with the OMAP_BO_MEM_DMABUF flag set) > + * if they are physically contiguous (when sgt->orig_nents == 1) > + * > + * - buffers mapped through the TILER when paddr_cnt is not zero, in > + * which case the DMA address points to the TILER aperture > + * > + * Physically contiguous buffers have their DMA address equal to the > + * physical address as we don't remap those buffers through the TILER. > + * > + * Buffers mapped to the TILER have their DMA address pointing to the > + * TILER aperture. As TILER mappings are refcounted (through paddr_cnt) > + * the DMA address must be accessed through omap_get_get_paddr() to > + * ensure that the mapping won't disappear unexpectedly. References must > + * be released with omap_gem_put_paddr(). > */ > dma_addr_t paddr; > > @@ -69,6 +78,12 @@ struct omap_gem_object { > uint32_t paddr_cnt; > > /** > + * If the buffer has been imported from a dmabuf the OMAP_DB_DMABUF flag > + * is set and the sgt field is valid. > + */ > + struct sg_table *sgt; > + > + /** > * tiler block used when buffer is remapped in DMM/TILER. > */ > struct tiler_block *block; > @@ -166,6 +181,17 @@ static uint64_t mmap_offset(struct drm_gem_object *obj) > return drm_vma_node_offset_addr(&obj->vma_node); > } > > +static bool is_contiguous(struct omap_gem_object *omap_obj) > +{ > + if (omap_obj->flags & OMAP_BO_MEM_DMA_API) > + return true; > + > + if ((omap_obj->flags & OMAP_BO_MEM_DMABUF) && omap_obj->sgt->nents == 1) > + return true; > + > + return false; > +} > + > /* ----------------------------------------------------------------------------- > * Eviction > */ > @@ -384,7 +410,7 @@ static int fault_1d(struct drm_gem_object *obj, > omap_gem_cpu_sync(obj, pgoff); > pfn = page_to_pfn(omap_obj->pages[pgoff]); > } else { > - BUG_ON(!(omap_obj->flags & OMAP_BO_MEM_DMA_API)); > + BUG_ON(!is_contiguous(omap_obj)); > pfn = (omap_obj->paddr >> PAGE_SHIFT) + pgoff; > } > > @@ -774,8 +800,7 @@ int omap_gem_get_paddr(struct drm_gem_object *obj, > > mutex_lock(&obj->dev->struct_mutex); > > - if (!(omap_obj->flags & OMAP_BO_MEM_DMA_API) && > - remap && priv->usergart) { > + if (!is_contiguous(omap_obj) && remap && priv->usergart) { > if (omap_obj->paddr_cnt == 0) { > struct page **pages; > uint32_t npages = obj->size >> PAGE_SHIFT; > @@ -822,7 +847,7 @@ int omap_gem_get_paddr(struct drm_gem_object *obj, > omap_obj->paddr_cnt++; > > *paddr = omap_obj->paddr; > - } else if (omap_obj->flags & OMAP_BO_MEM_DMA_API) { > + } else if (is_contiguous(omap_obj)) { > *paddr = omap_obj->paddr; > } else { > ret = -EINVAL; > @@ -1290,9 +1315,6 @@ unlock: > * Constructor & Destructor > */ > > -/* don't call directly.. called from GEM core when it is time to actually > - * free the object.. > - */ > void omap_gem_free_object(struct drm_gem_object *obj) > { > struct drm_device *dev = obj->dev; > @@ -1314,14 +1336,20 @@ void omap_gem_free_object(struct drm_gem_object *obj) > > /* don't free externally allocated backing memory */ > if (!(omap_obj->flags & OMAP_BO_MEM_EXT)) { > - if (omap_obj->pages) > - omap_gem_detach_pages(obj); > + if (omap_obj->pages) { > + if (omap_obj->flags & OMAP_BO_MEM_DMABUF) > + kfree(omap_obj->pages); > + else > + omap_gem_detach_pages(obj); > + } > > if (omap_obj->flags & OMAP_BO_MEM_DMA_API) { > dma_free_writecombine(dev->dev, obj->size, > omap_obj->vaddr, omap_obj->paddr); > } else if (omap_obj->vaddr) { > vunmap(omap_obj->vaddr); > + } else if (obj->import_attach) { > + drm_prime_gem_destroy(obj, omap_obj->sgt); > } > } > > @@ -1367,14 +1395,15 @@ struct drm_gem_object *omap_gem_new(struct drm_device *dev, > flags |= tiler_get_cpu_cache_flags(); > } else if ((flags & OMAP_BO_SCANOUT) && !priv->usergart) { > /* > - * Use contiguous memory if we don't have DMM to remap > - * discontiguous buffers. > + * OMAP_BO_SCANOUT hints that the buffer doesn't need to be > + * tiled. However, to lower the pressure on memory allocation, > + * use contiguous memory only if no TILER is available. > */ > flags |= OMAP_BO_MEM_DMA_API; > - } else if (!(flags & OMAP_BO_MEM_EXT)) { > + } else if (!(flags & (OMAP_BO_MEM_EXT | OMAP_BO_MEM_DMABUF))) { > /* > - * All other buffers not backed with external memory are > - * shmem-backed. > + * All other buffers not backed by external memory or dma_buf > + * are shmem-backed. > */ > flags |= OMAP_BO_MEM_SHMEM; > } > @@ -1436,6 +1465,67 @@ fail: > return NULL; > } > > +struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size, > + struct sg_table *sgt) > +{ > + struct omap_drm_private *priv = dev->dev_private; > + struct omap_gem_object *omap_obj; > + struct drm_gem_object *obj; > + union omap_gem_size gsize; > + > + /* Without a DMM only physically contiguous buffers can be supported. */ > + if (sgt->orig_nents != 1 && !priv->usergart) > + return ERR_PTR(-EINVAL); > + > + mutex_lock(&dev->struct_mutex); > + > + gsize.bytes = PAGE_ALIGN(size); > + obj = omap_gem_new(dev, gsize, OMAP_BO_MEM_DMABUF | OMAP_BO_WC); > + if (!obj) { > + obj = ERR_PTR(-ENOMEM); > + goto done; > + } > + > + omap_obj = to_omap_bo(obj); > + omap_obj->sgt = sgt; > + > + if (sgt->orig_nents == 1) { > + omap_obj->paddr = sg_dma_address(sgt->sgl); > + } else { > + /* Create pages list from sgt */ > + struct sg_page_iter iter; > + struct page **pages; > + unsigned int npages; > + unsigned int i = 0; > + > + npages = DIV_ROUND_UP(size, PAGE_SIZE); > + pages = kcalloc(npages, sizeof(*pages), GFP_KERNEL); > + if (!pages) { > + omap_gem_free_object(obj); > + obj = ERR_PTR(-ENOMEM); > + goto done; > + } > + > + omap_obj->pages = pages; > + > + for_each_sg_page(sgt->sgl, &iter, sgt->orig_nents, 0) { > + pages[i++] = sg_page_iter_page(&iter); > + if (i > npages) > + break; > + } > + > + if (WARN_ON(i != npages)) { > + omap_gem_free_object(obj); > + obj = ERR_PTR(-ENOMEM); > + goto done; > + } > + } > + > +done: > + mutex_unlock(&dev->struct_mutex); > + return obj; > +} > + > /* convenience method to construct a GEM buffer object, and userspace handle */ > int omap_gem_new_handle(struct drm_device *dev, struct drm_file *file, > union omap_gem_size gsize, uint32_t flags, uint32_t *handle) > diff --git a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c > index 27c297672076..3f7d25a8baf1 100644 > --- a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c > +++ b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c > @@ -21,6 +21,10 @@ > > #include "omap_drv.h" > > +/* ----------------------------------------------------------------------------- > + * DMABUF Export > + */ > + > static struct sg_table *omap_gem_map_dma_buf( > struct dma_buf_attachment *attachment, > enum dma_data_direction dir) > @@ -170,6 +174,10 @@ struct dma_buf *omap_gem_prime_export(struct drm_device *dev, > { > DEFINE_DMA_BUF_EXPORT_INFO(exp_info); > > + /* Don't allow exporting buffers that have been imported. */ > + if (obj->import_attach) > + return ERR_PTR(-EINVAL); > + > exp_info.ops = &omap_dmabuf_ops; > exp_info.size = obj->size; > exp_info.flags = flags; > @@ -178,15 +186,20 @@ struct dma_buf *omap_gem_prime_export(struct drm_device *dev, > return dma_buf_export(&exp_info); > } > > +/* ----------------------------------------------------------------------------- > + * DMABUF Import > + */ > + > struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev, > - struct dma_buf *buffer) > + struct dma_buf *dma_buf) > { > + struct dma_buf_attachment *attach; > struct drm_gem_object *obj; > + struct sg_table *sgt; > + int ret; > > - /* is this one of own objects? */ > - if (buffer->ops == &omap_dmabuf_ops) { > - obj = buffer->priv; > - /* is it from our device? */ > + if (dma_buf->ops == &omap_dmabuf_ops) { > + obj = dma_buf->priv; > if (obj->dev == dev) { > /* > * Importing dmabuf exported from out own gem increases > @@ -197,9 +210,33 @@ struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev, > } > } > > - /* > - * TODO add support for importing buffers from other devices.. > - * for now we don't need this but would be nice to add eventually > - */ > - return ERR_PTR(-EINVAL); > + attach = dma_buf_attach(dma_buf, dev->dev); > + if (IS_ERR(attach)) > + return ERR_CAST(attach); > + > + get_dma_buf(dma_buf); > + > + sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL); > + if (IS_ERR(sgt)) { > + ret = PTR_ERR(sgt); > + goto fail_detach; > + } > + > + obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt); > + if (IS_ERR(obj)) { > + ret = PTR_ERR(obj); > + goto fail_unmap; > + } > + > + obj->import_attach = attach; > + > + return obj; > + > +fail_unmap: > + dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL); > +fail_detach: > + dma_buf_detach(dma_buf, attach); > + dma_buf_put(dma_buf); > + > + return ERR_PTR(ret); > } > -- > 2.4.10 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel
Hi Daniel, On Saturday 05 December 2015 16:40:14 Daniel Vetter wrote: > On Sat, Dec 05, 2015 at 12:27:19AM +0200, Laurent Pinchart wrote: > > OMAP GEM objects backed by dma_buf reuse the current OMAP GEM object > > support as much as possible. If the imported buffer is physically > > contiguous its physical address will be used directly, reusing the > > OMAP_BO_MEM_DMA_API code paths. Otherwise it will be mapped through the > > TILER using a pages list created from the scatterlist instead of the > > shmem backing storage. > > > > Disallow exporting imported buffers for now as those code paths haven't > > been verified. Use cases of such a feature are suspicious anyway. > > If you export a buffer that's been imported the drm_prime.c helpers should > dig out the original dma-buf again. You should never end up with a dma-buf > -> omap gem bo -> dma-buf chain. > > If that doesn't work then there's a bug somewhere ... Very good point. I'll drop the check. Thank you for the review. > > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > > --- > > > > drivers/gpu/drm/omapdrm/omap_drv.h | 2 + > > drivers/gpu/drm/omapdrm/omap_gem.c | 138 +++++++++++++++++++------ > > drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 57 +++++++++--- > > 3 files changed, 163 insertions(+), 34 deletions(-)
diff --git a/drivers/gpu/drm/omapdrm/omap_drv.h b/drivers/gpu/drm/omapdrm/omap_drv.h index 97fcb892fdd7..6615b7d51ee3 100644 --- a/drivers/gpu/drm/omapdrm/omap_drv.h +++ b/drivers/gpu/drm/omapdrm/omap_drv.h @@ -200,6 +200,8 @@ void omap_gem_deinit(struct drm_device *dev); struct drm_gem_object *omap_gem_new(struct drm_device *dev, union omap_gem_size gsize, uint32_t flags); +struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size, + struct sg_table *sgt); int omap_gem_new_handle(struct drm_device *dev, struct drm_file *file, union omap_gem_size gsize, uint32_t flags, uint32_t *handle); void omap_gem_free_object(struct drm_gem_object *obj); diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c index 11df4f78d8a7..8a54d333a47b 100644 --- a/drivers/gpu/drm/omapdrm/omap_gem.c +++ b/drivers/gpu/drm/omapdrm/omap_gem.c @@ -33,6 +33,7 @@ #define OMAP_BO_MEM_DMA_API 0x01000000 /* memory allocated with the dma_alloc_* API */ #define OMAP_BO_MEM_SHMEM 0x02000000 /* memory allocated through shmem backing */ #define OMAP_BO_MEM_EXT 0x04000000 /* memory allocated externally */ +#define OMAP_BO_MEM_DMABUF 0x08000000 /* memory imported from a dmabuf */ #define OMAP_BO_EXT_SYNC 0x10000000 /* externally allocated sync object */ struct omap_gem_object { @@ -49,17 +50,25 @@ struct omap_gem_object { uint32_t roll; /** - * If buffer is allocated physically contiguous, the OMAP_BO_MEM_DMA_API - * flag is set and the paddr is valid. Also if the buffer is remapped - * in TILER and paddr_cnt > 0, then paddr is valid. But if you are using - * the physical address and OMAP_BO_MEM_DMA_API is not set, then you - * should be going thru omap_gem_{get,put}_paddr() to ensure the mapping - * is not removed from under your feet. + * paddr contains the buffer DMA address. It is valid for * - * Note that OMAP_BO_SCANOUT is a hint from userspace that DMA capable - * buffer is requested, but doesn't mean that it is. Use the - * OMAP_BO_MEM_DMA_API flag to determine if the buffer has a DMA capable - * physical address. + * - buffers allocated through the DMA mapping API (with the + * OMAP_BO_MEM_DMA_API flag set) + * + * - buffers imported from dmabuf (with the OMAP_BO_MEM_DMABUF flag set) + * if they are physically contiguous (when sgt->orig_nents == 1) + * + * - buffers mapped through the TILER when paddr_cnt is not zero, in + * which case the DMA address points to the TILER aperture + * + * Physically contiguous buffers have their DMA address equal to the + * physical address as we don't remap those buffers through the TILER. + * + * Buffers mapped to the TILER have their DMA address pointing to the + * TILER aperture. As TILER mappings are refcounted (through paddr_cnt) + * the DMA address must be accessed through omap_get_get_paddr() to + * ensure that the mapping won't disappear unexpectedly. References must + * be released with omap_gem_put_paddr(). */ dma_addr_t paddr; @@ -69,6 +78,12 @@ struct omap_gem_object { uint32_t paddr_cnt; /** + * If the buffer has been imported from a dmabuf the OMAP_DB_DMABUF flag + * is set and the sgt field is valid. + */ + struct sg_table *sgt; + + /** * tiler block used when buffer is remapped in DMM/TILER. */ struct tiler_block *block; @@ -166,6 +181,17 @@ static uint64_t mmap_offset(struct drm_gem_object *obj) return drm_vma_node_offset_addr(&obj->vma_node); } +static bool is_contiguous(struct omap_gem_object *omap_obj) +{ + if (omap_obj->flags & OMAP_BO_MEM_DMA_API) + return true; + + if ((omap_obj->flags & OMAP_BO_MEM_DMABUF) && omap_obj->sgt->nents == 1) + return true; + + return false; +} + /* ----------------------------------------------------------------------------- * Eviction */ @@ -384,7 +410,7 @@ static int fault_1d(struct drm_gem_object *obj, omap_gem_cpu_sync(obj, pgoff); pfn = page_to_pfn(omap_obj->pages[pgoff]); } else { - BUG_ON(!(omap_obj->flags & OMAP_BO_MEM_DMA_API)); + BUG_ON(!is_contiguous(omap_obj)); pfn = (omap_obj->paddr >> PAGE_SHIFT) + pgoff; } @@ -774,8 +800,7 @@ int omap_gem_get_paddr(struct drm_gem_object *obj, mutex_lock(&obj->dev->struct_mutex); - if (!(omap_obj->flags & OMAP_BO_MEM_DMA_API) && - remap && priv->usergart) { + if (!is_contiguous(omap_obj) && remap && priv->usergart) { if (omap_obj->paddr_cnt == 0) { struct page **pages; uint32_t npages = obj->size >> PAGE_SHIFT; @@ -822,7 +847,7 @@ int omap_gem_get_paddr(struct drm_gem_object *obj, omap_obj->paddr_cnt++; *paddr = omap_obj->paddr; - } else if (omap_obj->flags & OMAP_BO_MEM_DMA_API) { + } else if (is_contiguous(omap_obj)) { *paddr = omap_obj->paddr; } else { ret = -EINVAL; @@ -1290,9 +1315,6 @@ unlock: * Constructor & Destructor */ -/* don't call directly.. called from GEM core when it is time to actually - * free the object.. - */ void omap_gem_free_object(struct drm_gem_object *obj) { struct drm_device *dev = obj->dev; @@ -1314,14 +1336,20 @@ void omap_gem_free_object(struct drm_gem_object *obj) /* don't free externally allocated backing memory */ if (!(omap_obj->flags & OMAP_BO_MEM_EXT)) { - if (omap_obj->pages) - omap_gem_detach_pages(obj); + if (omap_obj->pages) { + if (omap_obj->flags & OMAP_BO_MEM_DMABUF) + kfree(omap_obj->pages); + else + omap_gem_detach_pages(obj); + } if (omap_obj->flags & OMAP_BO_MEM_DMA_API) { dma_free_writecombine(dev->dev, obj->size, omap_obj->vaddr, omap_obj->paddr); } else if (omap_obj->vaddr) { vunmap(omap_obj->vaddr); + } else if (obj->import_attach) { + drm_prime_gem_destroy(obj, omap_obj->sgt); } } @@ -1367,14 +1395,15 @@ struct drm_gem_object *omap_gem_new(struct drm_device *dev, flags |= tiler_get_cpu_cache_flags(); } else if ((flags & OMAP_BO_SCANOUT) && !priv->usergart) { /* - * Use contiguous memory if we don't have DMM to remap - * discontiguous buffers. + * OMAP_BO_SCANOUT hints that the buffer doesn't need to be + * tiled. However, to lower the pressure on memory allocation, + * use contiguous memory only if no TILER is available. */ flags |= OMAP_BO_MEM_DMA_API; - } else if (!(flags & OMAP_BO_MEM_EXT)) { + } else if (!(flags & (OMAP_BO_MEM_EXT | OMAP_BO_MEM_DMABUF))) { /* - * All other buffers not backed with external memory are - * shmem-backed. + * All other buffers not backed by external memory or dma_buf + * are shmem-backed. */ flags |= OMAP_BO_MEM_SHMEM; } @@ -1436,6 +1465,67 @@ fail: return NULL; } +struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size, + struct sg_table *sgt) +{ + struct omap_drm_private *priv = dev->dev_private; + struct omap_gem_object *omap_obj; + struct drm_gem_object *obj; + union omap_gem_size gsize; + + /* Without a DMM only physically contiguous buffers can be supported. */ + if (sgt->orig_nents != 1 && !priv->usergart) + return ERR_PTR(-EINVAL); + + mutex_lock(&dev->struct_mutex); + + gsize.bytes = PAGE_ALIGN(size); + obj = omap_gem_new(dev, gsize, OMAP_BO_MEM_DMABUF | OMAP_BO_WC); + if (!obj) { + obj = ERR_PTR(-ENOMEM); + goto done; + } + + omap_obj = to_omap_bo(obj); + omap_obj->sgt = sgt; + + if (sgt->orig_nents == 1) { + omap_obj->paddr = sg_dma_address(sgt->sgl); + } else { + /* Create pages list from sgt */ + struct sg_page_iter iter; + struct page **pages; + unsigned int npages; + unsigned int i = 0; + + npages = DIV_ROUND_UP(size, PAGE_SIZE); + pages = kcalloc(npages, sizeof(*pages), GFP_KERNEL); + if (!pages) { + omap_gem_free_object(obj); + obj = ERR_PTR(-ENOMEM); + goto done; + } + + omap_obj->pages = pages; + + for_each_sg_page(sgt->sgl, &iter, sgt->orig_nents, 0) { + pages[i++] = sg_page_iter_page(&iter); + if (i > npages) + break; + } + + if (WARN_ON(i != npages)) { + omap_gem_free_object(obj); + obj = ERR_PTR(-ENOMEM); + goto done; + } + } + +done: + mutex_unlock(&dev->struct_mutex); + return obj; +} + /* convenience method to construct a GEM buffer object, and userspace handle */ int omap_gem_new_handle(struct drm_device *dev, struct drm_file *file, union omap_gem_size gsize, uint32_t flags, uint32_t *handle) diff --git a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c index 27c297672076..3f7d25a8baf1 100644 --- a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c +++ b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c @@ -21,6 +21,10 @@ #include "omap_drv.h" +/* ----------------------------------------------------------------------------- + * DMABUF Export + */ + static struct sg_table *omap_gem_map_dma_buf( struct dma_buf_attachment *attachment, enum dma_data_direction dir) @@ -170,6 +174,10 @@ struct dma_buf *omap_gem_prime_export(struct drm_device *dev, { DEFINE_DMA_BUF_EXPORT_INFO(exp_info); + /* Don't allow exporting buffers that have been imported. */ + if (obj->import_attach) + return ERR_PTR(-EINVAL); + exp_info.ops = &omap_dmabuf_ops; exp_info.size = obj->size; exp_info.flags = flags; @@ -178,15 +186,20 @@ struct dma_buf *omap_gem_prime_export(struct drm_device *dev, return dma_buf_export(&exp_info); } +/* ----------------------------------------------------------------------------- + * DMABUF Import + */ + struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev, - struct dma_buf *buffer) + struct dma_buf *dma_buf) { + struct dma_buf_attachment *attach; struct drm_gem_object *obj; + struct sg_table *sgt; + int ret; - /* is this one of own objects? */ - if (buffer->ops == &omap_dmabuf_ops) { - obj = buffer->priv; - /* is it from our device? */ + if (dma_buf->ops == &omap_dmabuf_ops) { + obj = dma_buf->priv; if (obj->dev == dev) { /* * Importing dmabuf exported from out own gem increases @@ -197,9 +210,33 @@ struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev, } } - /* - * TODO add support for importing buffers from other devices.. - * for now we don't need this but would be nice to add eventually - */ - return ERR_PTR(-EINVAL); + attach = dma_buf_attach(dma_buf, dev->dev); + if (IS_ERR(attach)) + return ERR_CAST(attach); + + get_dma_buf(dma_buf); + + sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL); + if (IS_ERR(sgt)) { + ret = PTR_ERR(sgt); + goto fail_detach; + } + + obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt); + if (IS_ERR(obj)) { + ret = PTR_ERR(obj); + goto fail_unmap; + } + + obj->import_attach = attach; + + return obj; + +fail_unmap: + dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL); +fail_detach: + dma_buf_detach(dma_buf, attach); + dma_buf_put(dma_buf); + + return ERR_PTR(ret); }
OMAP GEM objects backed by dma_buf reuse the current OMAP GEM object support as much as possible. If the imported buffer is physically contiguous its physical address will be used directly, reusing the OMAP_BO_MEM_DMA_API code paths. Otherwise it will be mapped through the TILER using a pages list created from the scatterlist instead of the shmem backing storage. Disallow exporting imported buffers for now as those code paths haven't been verified. Use cases of such a feature are suspicious anyway. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> --- drivers/gpu/drm/omapdrm/omap_drv.h | 2 + drivers/gpu/drm/omapdrm/omap_gem.c | 138 ++++++++++++++++++++++++------ drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 57 +++++++++--- 3 files changed, 163 insertions(+), 34 deletions(-)