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.
Signed-off-by: Laurent Pinchart laurent.pinchart@ideasonboard.com ---
Changes since v1:
- Drop the dma-buf reexport check, reexport is handled by the DRM core --- drivers/gpu/drm/omapdrm/omap_drv.h | 2 + drivers/gpu/drm/omapdrm/omap_gem.c | 138 ++++++++++++++++++++++++------ drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 53 +++++++++--- 3 files changed, 159 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 51580eaa37af..2beb78632279 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..19e426b698d3 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) @@ -178,15 +182,20 @@ 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 +206,33 @@ 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); }