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);
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);
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;
__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--)
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;
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);
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",
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]);
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)
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 = {
.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");
projects / cascardo / linux.git / blobdiff