diff options
Diffstat (limited to 'drivers/media/v4l2-core/videobuf2-dma-sg.c')
| -rw-r--r-- | drivers/media/v4l2-core/videobuf2-dma-sg.c | 425 |
1 files changed, 407 insertions, 18 deletions
diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c index 9b163a440f89..b1838abb6d00 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-sg.c +++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c @@ -30,17 +30,30 @@ module_param(debug, int, 0644); printk(KERN_DEBUG "vb2-dma-sg: " fmt, ## arg); \ } while (0) +struct vb2_dma_sg_conf { + struct device *dev; +}; + struct vb2_dma_sg_buf { + struct device *dev; void *vaddr; struct page **pages; - int write; int offset; + enum dma_data_direction dma_dir; struct sg_table sg_table; + /* + * This will point to sg_table when used with the MMAP or USERPTR + * memory model, and to the dma_buf sglist when used with the + * DMABUF memory model. + */ + struct sg_table *dma_sgt; size_t size; unsigned int num_pages; atomic_t refcount; struct vb2_vmarea_handler handler; struct vm_area_struct *vma; + + struct dma_buf_attachment *db_attach; }; static void vb2_dma_sg_put(void *buf_priv); @@ -86,22 +99,31 @@ static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf, return 0; } -static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_flags) +static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, + enum dma_data_direction dma_dir, gfp_t gfp_flags) { + struct vb2_dma_sg_conf *conf = alloc_ctx; struct vb2_dma_sg_buf *buf; + struct sg_table *sgt; int ret; int num_pages; + DEFINE_DMA_ATTRS(attrs); + dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs); + + if (WARN_ON(alloc_ctx == NULL)) + return NULL; buf = kzalloc(sizeof *buf, GFP_KERNEL); if (!buf) return NULL; buf->vaddr = NULL; - buf->write = 0; + buf->dma_dir = dma_dir; buf->offset = 0; buf->size = size; /* size is already page aligned */ buf->num_pages = size >> PAGE_SHIFT; + buf->dma_sgt = &buf->sg_table; buf->pages = kzalloc(buf->num_pages * sizeof(struct page *), GFP_KERNEL); @@ -112,11 +134,23 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_fla if (ret) goto fail_pages_alloc; - ret = sg_alloc_table_from_pages(&buf->sg_table, buf->pages, + ret = sg_alloc_table_from_pages(buf->dma_sgt, buf->pages, buf->num_pages, 0, size, GFP_KERNEL); if (ret) goto fail_table_alloc; + /* Prevent the device from being released while the buffer is used */ + buf->dev = get_device(conf->dev); + + sgt = &buf->sg_table; + /* + * No need to sync to the device, this will happen later when the + * prepare() memop is called. + */ + if (dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->nents, + buf->dma_dir, &attrs) == 0) + goto fail_map; + buf->handler.refcount = &buf->refcount; buf->handler.put = vb2_dma_sg_put; buf->handler.arg = buf; @@ -127,6 +161,9 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_fla __func__, buf->num_pages); return buf; +fail_map: + put_device(buf->dev); + sg_free_table(buf->dma_sgt); fail_table_alloc: num_pages = buf->num_pages; while (num_pages--) @@ -141,42 +178,81 @@ fail_pages_array_alloc: static void vb2_dma_sg_put(void *buf_priv) { struct vb2_dma_sg_buf *buf = buf_priv; + struct sg_table *sgt = &buf->sg_table; int i = buf->num_pages; if (atomic_dec_and_test(&buf->refcount)) { + DEFINE_DMA_ATTRS(attrs); + + dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs); dprintk(1, "%s: Freeing buffer of %d pages\n", __func__, buf->num_pages); + dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->nents, + buf->dma_dir, &attrs); if (buf->vaddr) vm_unmap_ram(buf->vaddr, buf->num_pages); - sg_free_table(&buf->sg_table); + sg_free_table(buf->dma_sgt); while (--i >= 0) __free_page(buf->pages[i]); kfree(buf->pages); + put_device(buf->dev); kfree(buf); } } +static void vb2_dma_sg_prepare(void *buf_priv) +{ + struct vb2_dma_sg_buf *buf = buf_priv; + struct sg_table *sgt = buf->dma_sgt; + + /* DMABUF exporter will flush the cache for us */ + if (buf->db_attach) + return; + + dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); +} + +static void vb2_dma_sg_finish(void *buf_priv) +{ + struct vb2_dma_sg_buf *buf = buf_priv; + struct sg_table *sgt = buf->dma_sgt; + + /* DMABUF exporter will flush the cache for us */ + if (buf->db_attach) + return; + + dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); +} + static inline int vma_is_io(struct vm_area_struct *vma) { return !!(vma->vm_flags & (VM_IO | VM_PFNMAP)); } static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, - unsigned long size, int write) + unsigned long size, + enum dma_data_direction dma_dir) { + struct vb2_dma_sg_conf *conf = alloc_ctx; struct vb2_dma_sg_buf *buf; unsigned long first, last; int num_pages_from_user; struct vm_area_struct *vma; + struct sg_table *sgt; + DEFINE_DMA_ATTRS(attrs); + + dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs); buf = kzalloc(sizeof *buf, GFP_KERNEL); if (!buf) return NULL; buf->vaddr = NULL; - buf->write = write; + buf->dev = conf->dev; + buf->dma_dir = dma_dir; buf->offset = vaddr & ~PAGE_MASK; buf->size = size; + buf->dma_sgt = &buf->sg_table; first = (vaddr & PAGE_MASK) >> PAGE_SHIFT; last = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT; @@ -221,7 +297,7 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, num_pages_from_user = get_user_pages(current, current->mm, vaddr & PAGE_MASK, buf->num_pages, - write, + buf->dma_dir == DMA_FROM_DEVICE, 1, /* force */ buf->pages, NULL); @@ -229,12 +305,22 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, if (num_pages_from_user != buf->num_pages) goto userptr_fail_get_user_pages; - if (sg_alloc_table_from_pages(&buf->sg_table, buf->pages, + if (sg_alloc_table_from_pages(buf->dma_sgt, buf->pages, buf->num_pages, buf->offset, size, 0)) goto userptr_fail_alloc_table_from_pages; + sgt = &buf->sg_table; + /* + * No need to sync to the device, this will happen later when the + * prepare() memop is called. + */ + if (dma_map_sg_attrs(buf->dev, sgt->sgl, sgt->nents, + buf->dma_dir, &attrs) == 0) + goto userptr_fail_map; return buf; +userptr_fail_map: + sg_free_table(&buf->sg_table); userptr_fail_alloc_table_from_pages: userptr_fail_get_user_pages: dprintk(1, "get_user_pages requested/got: %d/%d]\n", @@ -257,15 +343,20 @@ userptr_fail_alloc_pages: static void vb2_dma_sg_put_userptr(void *buf_priv) { struct vb2_dma_sg_buf *buf = buf_priv; + struct sg_table *sgt = &buf->sg_table; int i = buf->num_pages; + DEFINE_DMA_ATTRS(attrs); + + dma_set_attr(DMA_ATTR_SKIP_CPU_SYNC, &attrs); dprintk(1, "%s: Releasing userspace buffer of %d pages\n", __func__, buf->num_pages); + dma_unmap_sg_attrs(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir, &attrs); if (buf->vaddr) vm_unmap_ram(buf->vaddr, buf->num_pages); - sg_free_table(&buf->sg_table); + sg_free_table(buf->dma_sgt); while (--i >= 0) { - if (buf->write) + if (buf->dma_dir == DMA_FROM_DEVICE) set_page_dirty_lock(buf->pages[i]); if (!vma_is_io(buf->vma)) put_page(buf->pages[i]); @@ -281,14 +372,16 @@ static void *vb2_dma_sg_vaddr(void *buf_priv) BUG_ON(!buf); - if (!buf->vaddr) - buf->vaddr = vm_map_ram(buf->pages, - buf->num_pages, - -1, - PAGE_KERNEL); + if (!buf->vaddr) { + if (buf->db_attach) + buf->vaddr = dma_buf_vmap(buf->db_attach->dmabuf); + else + buf->vaddr = vm_map_ram(buf->pages, + buf->num_pages, -1, PAGE_KERNEL); + } /* add offset in case userptr is not page-aligned */ - return buf->vaddr + buf->offset; + return buf->vaddr ? buf->vaddr + buf->offset : NULL; } static unsigned int vb2_dma_sg_num_users(void *buf_priv) @@ -335,11 +428,279 @@ static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma) return 0; } +/*********************************************/ +/* DMABUF ops for exporters */ +/*********************************************/ + +struct vb2_dma_sg_attachment { + struct sg_table sgt; + enum dma_data_direction dma_dir; +}; + +static int vb2_dma_sg_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev, + struct dma_buf_attachment *dbuf_attach) +{ + struct vb2_dma_sg_attachment *attach; + unsigned int i; + struct scatterlist *rd, *wr; + struct sg_table *sgt; + struct vb2_dma_sg_buf *buf = dbuf->priv; + int ret; + + attach = kzalloc(sizeof(*attach), GFP_KERNEL); + if (!attach) + return -ENOMEM; + + sgt = &attach->sgt; + /* Copy the buf->base_sgt scatter list to the attachment, as we can't + * map the same scatter list to multiple attachments at the same time. + */ + ret = sg_alloc_table(sgt, buf->dma_sgt->orig_nents, GFP_KERNEL); + if (ret) { + kfree(attach); + return -ENOMEM; + } + + rd = buf->dma_sgt->sgl; + wr = sgt->sgl; + for (i = 0; i < sgt->orig_nents; ++i) { + sg_set_page(wr, sg_page(rd), rd->length, rd->offset); + rd = sg_next(rd); + wr = sg_next(wr); + } + + attach->dma_dir = DMA_NONE; + dbuf_attach->priv = attach; + + return 0; +} + +static void vb2_dma_sg_dmabuf_ops_detach(struct dma_buf *dbuf, + struct dma_buf_attachment *db_attach) +{ + struct vb2_dma_sg_attachment *attach = db_attach->priv; + struct sg_table *sgt; + + if (!attach) + return; + + sgt = &attach->sgt; + + /* release the scatterlist cache */ + if (attach->dma_dir != DMA_NONE) + dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, + attach->dma_dir); + sg_free_table(sgt); + kfree(attach); + db_attach->priv = NULL; +} + +static struct sg_table *vb2_dma_sg_dmabuf_ops_map( + struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir) +{ + struct vb2_dma_sg_attachment *attach = db_attach->priv; + /* stealing dmabuf mutex to serialize map/unmap operations */ + struct mutex *lock = &db_attach->dmabuf->lock; + struct sg_table *sgt; + int ret; + + mutex_lock(lock); + + sgt = &attach->sgt; + /* return previously mapped sg table */ + if (attach->dma_dir == dma_dir) { + mutex_unlock(lock); + return sgt; + } + + /* release any previous cache */ + if (attach->dma_dir != DMA_NONE) { + dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, + attach->dma_dir); + attach->dma_dir = DMA_NONE; + } + + /* mapping to the client with new direction */ + ret = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, dma_dir); + if (ret <= 0) { + pr_err("failed to map scatterlist\n"); + mutex_unlock(lock); + return ERR_PTR(-EIO); + } + + attach->dma_dir = dma_dir; + + mutex_unlock(lock); + + return sgt; +} + +static void vb2_dma_sg_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach, + struct sg_table *sgt, enum dma_data_direction dma_dir) +{ + /* nothing to be done here */ +} + +static void vb2_dma_sg_dmabuf_ops_release(struct dma_buf *dbuf) +{ + /* drop reference obtained in vb2_dma_sg_get_dmabuf */ + vb2_dma_sg_put(dbuf->priv); +} + +static void *vb2_dma_sg_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnum) +{ + struct vb2_dma_sg_buf *buf = dbuf->priv; + + return buf->vaddr ? buf->vaddr + pgnum * PAGE_SIZE : NULL; +} + +static void *vb2_dma_sg_dmabuf_ops_vmap(struct dma_buf *dbuf) +{ + struct vb2_dma_sg_buf *buf = dbuf->priv; + + return vb2_dma_sg_vaddr(buf); +} + +static int vb2_dma_sg_dmabuf_ops_mmap(struct dma_buf *dbuf, + struct vm_area_struct *vma) +{ + return vb2_dma_sg_mmap(dbuf->priv, vma); +} + +static struct dma_buf_ops vb2_dma_sg_dmabuf_ops = { + .attach = vb2_dma_sg_dmabuf_ops_attach, + .detach = vb2_dma_sg_dmabuf_ops_detach, + .map_dma_buf = vb2_dma_sg_dmabuf_ops_map, + .unmap_dma_buf = vb2_dma_sg_dmabuf_ops_unmap, + .kmap = vb2_dma_sg_dmabuf_ops_kmap, + .kmap_atomic = vb2_dma_sg_dmabuf_ops_kmap, + .vmap = vb2_dma_sg_dmabuf_ops_vmap, + .mmap = vb2_dma_sg_dmabuf_ops_mmap, + .release = vb2_dma_sg_dmabuf_ops_release, +}; + +static struct dma_buf *vb2_dma_sg_get_dmabuf(void *buf_priv, unsigned long flags) +{ + struct vb2_dma_sg_buf *buf = buf_priv; + struct dma_buf *dbuf; + + if (WARN_ON(!buf->dma_sgt)) + return NULL; + + dbuf = dma_buf_export(buf, &vb2_dma_sg_dmabuf_ops, buf->size, flags, NULL); + if (IS_ERR(dbuf)) + return NULL; + + /* dmabuf keeps reference to vb2 buffer */ + atomic_inc(&buf->refcount); + + return dbuf; +} + +/*********************************************/ +/* callbacks for DMABUF buffers */ +/*********************************************/ + +static int vb2_dma_sg_map_dmabuf(void *mem_priv) +{ + struct vb2_dma_sg_buf *buf = mem_priv; + struct sg_table *sgt; + + if (WARN_ON(!buf->db_attach)) { + pr_err("trying to pin a non attached buffer\n"); + return -EINVAL; + } + + if (WARN_ON(buf->dma_sgt)) { + pr_err("dmabuf buffer is already pinned\n"); + return 0; + } + + /* get the associated scatterlist for this buffer */ + sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir); + if (IS_ERR(sgt)) { + pr_err("Error getting dmabuf scatterlist\n"); + return -EINVAL; + } + + buf->dma_sgt = sgt; + buf->vaddr = NULL; + + return 0; +} + +static void vb2_dma_sg_unmap_dmabuf(void *mem_priv) +{ + struct vb2_dma_sg_buf *buf = mem_priv; + struct sg_table *sgt = buf->dma_sgt; + + if (WARN_ON(!buf->db_attach)) { + pr_err("trying to unpin a not attached buffer\n"); + return; + } + + if (WARN_ON(!sgt)) { + pr_err("dmabuf buffer is already unpinned\n"); + return; + } + + if (buf->vaddr) { + dma_buf_vunmap(buf->db_attach->dmabuf, buf->vaddr); + buf->vaddr = NULL; + } + dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir); + + buf->dma_sgt = NULL; +} + +static void vb2_dma_sg_detach_dmabuf(void *mem_priv) +{ + struct vb2_dma_sg_buf *buf = mem_priv; + + /* if vb2 works correctly you should never detach mapped buffer */ + if (WARN_ON(buf->dma_sgt)) + vb2_dma_sg_unmap_dmabuf(buf); + + /* detach this attachment */ + dma_buf_detach(buf->db_attach->dmabuf, buf->db_attach); + kfree(buf); +} + +static void *vb2_dma_sg_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf, + unsigned long size, enum dma_data_direction dma_dir) +{ + struct vb2_dma_sg_conf *conf = alloc_ctx; + struct vb2_dma_sg_buf *buf; + struct dma_buf_attachment *dba; + + if (dbuf->size < size) + return ERR_PTR(-EFAULT); + + buf = kzalloc(sizeof(*buf), GFP_KERNEL); + if (!buf) + return ERR_PTR(-ENOMEM); + + buf->dev = conf->dev; + /* create attachment for the dmabuf with the user device */ + dba = dma_buf_attach(dbuf, buf->dev); + if (IS_ERR(dba)) { + pr_err("failed to attach dmabuf\n"); + kfree(buf); + return dba; + } + + buf->dma_dir = dma_dir; + buf->size = size; + buf->db_attach = dba; + + return buf; +} + static void *vb2_dma_sg_cookie(void *buf_priv) { struct vb2_dma_sg_buf *buf = buf_priv; - return &buf->sg_table; + return buf->dma_sgt; } const struct vb2_mem_ops vb2_dma_sg_memops = { @@ -347,13 +708,41 @@ const struct vb2_mem_ops vb2_dma_sg_memops = { .put = vb2_dma_sg_put, .get_userptr = vb2_dma_sg_get_userptr, .put_userptr = vb2_dma_sg_put_userptr, + .prepare = vb2_dma_sg_prepare, + .finish = vb2_dma_sg_finish, .vaddr = vb2_dma_sg_vaddr, .mmap = vb2_dma_sg_mmap, .num_users = vb2_dma_sg_num_users, + .get_dmabuf = vb2_dma_sg_get_dmabuf, + .map_dmabuf = vb2_dma_sg_map_dmabuf, + .unmap_dmabuf = vb2_dma_sg_unmap_dmabuf, + .attach_dmabuf = vb2_dma_sg_attach_dmabuf, + .detach_dmabuf = vb2_dma_sg_detach_dmabuf, .cookie = vb2_dma_sg_cookie, }; EXPORT_SYMBOL_GPL(vb2_dma_sg_memops); +void *vb2_dma_sg_init_ctx(struct device *dev) +{ + struct vb2_dma_sg_conf *conf; + + conf = kzalloc(sizeof(*conf), GFP_KERNEL); + if (!conf) + return ERR_PTR(-ENOMEM); + + conf->dev = dev; + + return conf; +} +EXPORT_SYMBOL_GPL(vb2_dma_sg_init_ctx); + +void vb2_dma_sg_cleanup_ctx(void *alloc_ctx) +{ + if (!IS_ERR_OR_NULL(alloc_ctx)) + kfree(alloc_ctx); +} +EXPORT_SYMBOL_GPL(vb2_dma_sg_cleanup_ctx); + MODULE_DESCRIPTION("dma scatter/gather memory handling routines for videobuf2"); MODULE_AUTHOR("Andrzej Pietrasiewicz"); MODULE_LICENSE("GPL"); |