diff options
Diffstat (limited to 'drivers/media/common/videobuf2/videobuf2-dma-sg.c')
| -rw-r--r-- | drivers/media/common/videobuf2/videobuf2-dma-sg.c | 686 |
1 files changed, 686 insertions, 0 deletions
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c new file mode 100644 index 000000000..cb1e4bc69 --- /dev/null +++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c @@ -0,0 +1,686 @@ +/* + * videobuf2-dma-sg.c - dma scatter/gather memory allocator for videobuf2 + * + * Copyright (C) 2010 Samsung Electronics + * + * Author: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/refcount.h> +#include <linux/scatterlist.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> + +#include <media/videobuf2-v4l2.h> +#include <media/videobuf2-memops.h> +#include <media/videobuf2-dma-sg.h> + +static int debug; +module_param(debug, int, 0644); + +#define dprintk(level, fmt, arg...) \ + do { \ + if (debug >= level) \ + printk(KERN_DEBUG "vb2-dma-sg: " fmt, ## arg); \ + } while (0) + +struct vb2_dma_sg_buf { + struct device *dev; + void *vaddr; + struct page **pages; + struct frame_vector *vec; + 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; + refcount_t refcount; + struct vb2_vmarea_handler handler; + + struct dma_buf_attachment *db_attach; + + struct vb2_buffer *vb; +}; + +static void vb2_dma_sg_put(void *buf_priv); + +static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf, + gfp_t gfp_flags) +{ + unsigned int last_page = 0; + unsigned long size = buf->size; + + while (size > 0) { + struct page *pages; + int order; + int i; + + order = get_order(size); + /* Don't over allocate*/ + if ((PAGE_SIZE << order) > size) + order--; + + pages = NULL; + while (!pages) { + pages = alloc_pages(GFP_KERNEL | __GFP_ZERO | + __GFP_NOWARN | gfp_flags, order); + if (pages) + break; + + if (order == 0) { + while (last_page--) + __free_page(buf->pages[last_page]); + return -ENOMEM; + } + order--; + } + + split_page(pages, order); + for (i = 0; i < (1 << order); i++) + buf->pages[last_page++] = &pages[i]; + + size -= PAGE_SIZE << order; + } + + return 0; +} + +static void *vb2_dma_sg_alloc(struct vb2_buffer *vb, struct device *dev, + unsigned long size) +{ + struct vb2_dma_sg_buf *buf; + struct sg_table *sgt; + int ret; + int num_pages; + + if (WARN_ON(!dev) || WARN_ON(!size)) + return ERR_PTR(-EINVAL); + + buf = kzalloc(sizeof *buf, GFP_KERNEL); + if (!buf) + return ERR_PTR(-ENOMEM); + + buf->vaddr = NULL; + buf->dma_dir = vb->vb2_queue->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; + + /* + * NOTE: dma-sg allocates memory using the page allocator directly, so + * there is no memory consistency guarantee, hence dma-sg ignores DMA + * attributes passed from the upper layer. + */ + buf->pages = kvcalloc(buf->num_pages, sizeof(struct page *), GFP_KERNEL); + if (!buf->pages) + goto fail_pages_array_alloc; + + ret = vb2_dma_sg_alloc_compacted(buf, vb->vb2_queue->gfp_flags); + if (ret) + goto fail_pages_alloc; + + 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(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_sgtable(buf->dev, sgt, buf->dma_dir, + DMA_ATTR_SKIP_CPU_SYNC)) + goto fail_map; + + buf->handler.refcount = &buf->refcount; + buf->handler.put = vb2_dma_sg_put; + buf->handler.arg = buf; + buf->vb = vb; + + refcount_set(&buf->refcount, 1); + + dprintk(1, "%s: Allocated buffer of %d pages\n", + __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--) + __free_page(buf->pages[num_pages]); +fail_pages_alloc: + kvfree(buf->pages); +fail_pages_array_alloc: + kfree(buf); + return ERR_PTR(-ENOMEM); +} + +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 (refcount_dec_and_test(&buf->refcount)) { + dprintk(1, "%s: Freeing buffer of %d pages\n", __func__, + buf->num_pages); + dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, + DMA_ATTR_SKIP_CPU_SYNC); + if (buf->vaddr) + vm_unmap_ram(buf->vaddr, buf->num_pages); + sg_free_table(buf->dma_sgt); + while (--i >= 0) + __free_page(buf->pages[i]); + kvfree(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; + + if (buf->vb->skip_cache_sync_on_prepare) + return; + + dma_sync_sgtable_for_device(buf->dev, sgt, 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; + + if (buf->vb->skip_cache_sync_on_finish) + return; + + dma_sync_sgtable_for_cpu(buf->dev, sgt, buf->dma_dir); +} + +static void *vb2_dma_sg_get_userptr(struct vb2_buffer *vb, struct device *dev, + unsigned long vaddr, unsigned long size) +{ + struct vb2_dma_sg_buf *buf; + struct sg_table *sgt; + struct frame_vector *vec; + + if (WARN_ON(!dev)) + return ERR_PTR(-EINVAL); + + buf = kzalloc(sizeof *buf, GFP_KERNEL); + if (!buf) + return ERR_PTR(-ENOMEM); + + buf->vaddr = NULL; + buf->dev = dev; + buf->dma_dir = vb->vb2_queue->dma_dir; + buf->offset = vaddr & ~PAGE_MASK; + buf->size = size; + buf->dma_sgt = &buf->sg_table; + buf->vb = vb; + vec = vb2_create_framevec(vaddr, size); + if (IS_ERR(vec)) + goto userptr_fail_pfnvec; + buf->vec = vec; + + buf->pages = frame_vector_pages(vec); + if (IS_ERR(buf->pages)) + goto userptr_fail_sgtable; + buf->num_pages = frame_vector_count(vec); + + if (sg_alloc_table_from_pages(buf->dma_sgt, buf->pages, + buf->num_pages, buf->offset, size, 0)) + goto userptr_fail_sgtable; + + sgt = &buf->sg_table; + /* + * No need to sync to the device, this will happen later when the + * prepare() memop is called. + */ + if (dma_map_sgtable(buf->dev, sgt, buf->dma_dir, + DMA_ATTR_SKIP_CPU_SYNC)) + goto userptr_fail_map; + + return buf; + +userptr_fail_map: + sg_free_table(&buf->sg_table); +userptr_fail_sgtable: + vb2_destroy_framevec(vec); +userptr_fail_pfnvec: + kfree(buf); + return ERR_PTR(-ENOMEM); +} + +/* + * @put_userptr: inform the allocator that a USERPTR buffer will no longer + * be used + */ +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; + + dprintk(1, "%s: Releasing userspace buffer of %d pages\n", + __func__, buf->num_pages); + dma_unmap_sgtable(buf->dev, sgt, buf->dma_dir, DMA_ATTR_SKIP_CPU_SYNC); + if (buf->vaddr) + vm_unmap_ram(buf->vaddr, buf->num_pages); + sg_free_table(buf->dma_sgt); + if (buf->dma_dir == DMA_FROM_DEVICE || + buf->dma_dir == DMA_BIDIRECTIONAL) + while (--i >= 0) + set_page_dirty_lock(buf->pages[i]); + vb2_destroy_framevec(buf->vec); + kfree(buf); +} + +static void *vb2_dma_sg_vaddr(struct vb2_buffer *vb, void *buf_priv) +{ + struct vb2_dma_sg_buf *buf = buf_priv; + struct iosys_map map; + int ret; + + BUG_ON(!buf); + + if (!buf->vaddr) { + if (buf->db_attach) { + ret = dma_buf_vmap(buf->db_attach->dmabuf, &map); + buf->vaddr = ret ? NULL : map.vaddr; + } else { + buf->vaddr = vm_map_ram(buf->pages, buf->num_pages, -1); + } + } + + /* add offset in case userptr is not page-aligned */ + return buf->vaddr ? buf->vaddr + buf->offset : NULL; +} + +static unsigned int vb2_dma_sg_num_users(void *buf_priv) +{ + struct vb2_dma_sg_buf *buf = buf_priv; + + return refcount_read(&buf->refcount); +} + +static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma) +{ + struct vb2_dma_sg_buf *buf = buf_priv; + int err; + + if (!buf) { + printk(KERN_ERR "No memory to map\n"); + return -EINVAL; + } + + err = vm_map_pages(vma, buf->pages, buf->num_pages); + if (err) { + printk(KERN_ERR "Remapping memory, error: %d\n", err); + return err; + } + + /* + * Use common vm_area operations to track buffer refcount. + */ + vma->vm_private_data = &buf->handler; + vma->vm_ops = &vb2_common_vm_ops; + + vma->vm_ops->open(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 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_sgtable(db_attach->dev, sgt, attach->dma_dir, 0); + 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; + + 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_sgtable(db_attach->dev, sgt, attach->dma_dir, 0); + attach->dma_dir = DMA_NONE; + } + + /* mapping to the client with new direction */ + if (dma_map_sgtable(db_attach->dev, sgt, dma_dir, 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 int +vb2_dma_sg_dmabuf_ops_begin_cpu_access(struct dma_buf *dbuf, + enum dma_data_direction direction) +{ + struct vb2_dma_sg_buf *buf = dbuf->priv; + struct sg_table *sgt = buf->dma_sgt; + + dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); + return 0; +} + +static int +vb2_dma_sg_dmabuf_ops_end_cpu_access(struct dma_buf *dbuf, + enum dma_data_direction direction) +{ + struct vb2_dma_sg_buf *buf = dbuf->priv; + struct sg_table *sgt = buf->dma_sgt; + + dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); + return 0; +} + +static int vb2_dma_sg_dmabuf_ops_vmap(struct dma_buf *dbuf, + struct iosys_map *map) +{ + struct vb2_dma_sg_buf *buf; + void *vaddr; + + buf = dbuf->priv; + vaddr = vb2_dma_sg_vaddr(buf->vb, buf); + if (!vaddr) + return -EINVAL; + + iosys_map_set_vaddr(map, vaddr); + + return 0; +} + +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 const 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, + .begin_cpu_access = vb2_dma_sg_dmabuf_ops_begin_cpu_access, + .end_cpu_access = vb2_dma_sg_dmabuf_ops_end_cpu_access, + .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(struct vb2_buffer *vb, + void *buf_priv, + unsigned long flags) +{ + struct vb2_dma_sg_buf *buf = buf_priv; + struct dma_buf *dbuf; + DEFINE_DMA_BUF_EXPORT_INFO(exp_info); + + exp_info.ops = &vb2_dma_sg_dmabuf_ops; + exp_info.size = buf->size; + exp_info.flags = flags; + exp_info.priv = buf; + + if (WARN_ON(!buf->dma_sgt)) + return NULL; + + dbuf = dma_buf_export(&exp_info); + if (IS_ERR(dbuf)) + return NULL; + + /* dmabuf keeps reference to vb2 buffer */ + refcount_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; + struct iosys_map map = IOSYS_MAP_INIT_VADDR(buf->vaddr); + + 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, &map); + 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(struct vb2_buffer *vb, struct device *dev, + struct dma_buf *dbuf, unsigned long size) +{ + struct vb2_dma_sg_buf *buf; + struct dma_buf_attachment *dba; + + if (WARN_ON(!dev)) + return ERR_PTR(-EINVAL); + + if (dbuf->size < size) + return ERR_PTR(-EFAULT); + + buf = kzalloc(sizeof(*buf), GFP_KERNEL); + if (!buf) + return ERR_PTR(-ENOMEM); + + buf->dev = 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 = vb->vb2_queue->dma_dir; + buf->size = size; + buf->db_attach = dba; + buf->vb = vb; + + return buf; +} + +static void *vb2_dma_sg_cookie(struct vb2_buffer *vb, void *buf_priv) +{ + struct vb2_dma_sg_buf *buf = buf_priv; + + return buf->dma_sgt; +} + +const struct vb2_mem_ops vb2_dma_sg_memops = { + .alloc = vb2_dma_sg_alloc, + .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); + +MODULE_DESCRIPTION("dma scatter/gather memory handling routines for videobuf2"); +MODULE_AUTHOR("Andrzej Pietrasiewicz"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS(DMA_BUF); |