| Message ID | 1333634408-4960-12-git-send-email-t.stanislaws@samsung.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
Hi Tomasz, On Thursday 05 April 2012 16:00:08 Tomasz Stanislawski wrote: > From: Sumit Semwal <sumit.semwal@ti.com> > > This patch makes changes for adding dma-contig as a dma_buf user. It > provides function implementations for the {attach, detach, map, > unmap}_dmabuf() mem_ops of DMABUF memory type. > > Signed-off-by: Sumit Semwal <sumit.semwal@ti.com> > Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> > [author of the original patch] > Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com> > [integration with refactored dma-contig allocator] > --- > drivers/media/video/videobuf2-dma-contig.c | 117 +++++++++++++++++++++++++ > 1 files changed, 117 insertions(+), 0 deletions(-) > > diff --git a/drivers/media/video/videobuf2-dma-contig.c > b/drivers/media/video/videobuf2-dma-contig.c index 30f316588..6329483 > 100644 > --- a/drivers/media/video/videobuf2-dma-contig.c > +++ b/drivers/media/video/videobuf2-dma-contig.c > @@ -10,6 +10,7 @@ > * the Free Software Foundation. > */ > > +#include <linux/dma-buf.h> > #include <linux/module.h> > #include <linux/scatterlist.h> > #include <linux/sched.h> > @@ -33,6 +34,9 @@ struct vb2_dc_buf { > > /* USERPTR related */ > struct vm_area_struct *vma; > + > + /* DMABUF related */ > + struct dma_buf_attachment *db_attach; > }; > > /*********************************************/ > @@ -425,6 +429,115 @@ fail_buf: > } > > /*********************************************/ > +/* callbacks for DMABUF buffers */ > +/*********************************************/ > + > +static int vb2_dc_map_dmabuf(void *mem_priv) > +{ > + struct vb2_dc_buf *buf = mem_priv; > + struct sg_table *sgt; > + unsigned long contig_size; > + int ret = 0; > + > + if (WARN_ON(!buf->db_attach)) { > + printk(KERN_ERR "trying to pin a non attached buffer\n"); > + return -EINVAL; > + } > + > + if (WARN_ON(buf->dma_sgt)) { > + printk(KERN_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_OR_NULL(sgt)) { > + printk(KERN_ERR "Error getting dmabuf scatterlist\n"); > + return -EINVAL; > + } > + > + /* checking if dmabuf is big enough to store contiguous chunk */ > + contig_size = vb2_dc_get_contiguous_size(sgt); > + if (contig_size < buf->size) { > + printk(KERN_ERR "contiguous chunk of dmabuf is too small\n"); > + ret = -EFAULT; > + goto fail_map; The fail_map label is only used here, you can move the dma_buf_unmap_attachment() call here and return -EFAULT directly. > + } > + > + buf->dma_addr = sg_dma_address(sgt->sgl); > + buf->dma_sgt = sgt; > + > + return 0; > + > +fail_map: > + dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir); > + > + return ret; > +} > + > +static void vb2_dc_unmap_dmabuf(void *mem_priv) > +{ > + struct vb2_dc_buf *buf = mem_priv; > + struct sg_table *sgt = buf->dma_sgt; > + > + if (WARN_ON(!buf->db_attach)) { > + printk(KERN_ERR "trying to unpin a not attached buffer\n"); > + return; > + } > + > + if (WARN_ON(!sgt)) { > + printk(KERN_ERR "dmabuf buffer is already unpinned\n"); > + return; > + } > + > + dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir); > + > + buf->dma_addr = 0; > + buf->dma_sgt = NULL; > +} > + > +static void vb2_dc_detach_dmabuf(void *mem_priv) > +{ > + struct vb2_dc_buf *buf = mem_priv; > + > + if (buf->dma_addr) > + vb2_dc_unmap_dmabuf(buf); What would you think about calling vb2_dc_unmap_dmabuf() from vb2 core instead, to keep the map/unmap calls symmetrical (the second WARN_ON and the related printk in vb2_dc_unmap_dmabuf() might need to go then) ? > + /* detach this attachment */ > + dma_buf_detach(buf->db_attach->dmabuf, buf->db_attach); > + kfree(buf); > +} > + > +static void *vb2_dc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf, > + unsigned long size, int write) > +{ > + struct vb2_dc_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 = alloc_ctx; > + /* create attachment for the dmabuf with the user device */ > + dba = dma_buf_attach(dbuf, buf->dev); > + if (IS_ERR(dba)) { > + printk(KERN_ERR "failed to attach dmabuf\n"); > + kfree(buf); > + return dba; > + } > + > + buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE; > + buf->size = size; > + buf->db_attach = dba; > + > + return buf; > +} > + > +/*********************************************/ > /* DMA CONTIG exported functions */ > /*********************************************/ > > @@ -438,6 +551,10 @@ const struct vb2_mem_ops vb2_dma_contig_memops = { > .put_userptr = vb2_dc_put_userptr, > .prepare = vb2_dc_prepare, > .finish = vb2_dc_finish, > + .map_dmabuf = vb2_dc_map_dmabuf, > + .unmap_dmabuf = vb2_dc_unmap_dmabuf, > + .attach_dmabuf = vb2_dc_attach_dmabuf, > + .detach_dmabuf = vb2_dc_detach_dmabuf, > .num_users = vb2_dc_num_users, > }; > EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);
Hi Laurent, Thanks for review. On 04/06/2012 05:12 PM, Laurent Pinchart wrote: > Hi Tomasz, > > On Thursday 05 April 2012 16:00:08 Tomasz Stanislawski wrote: >> From: Sumit Semwal <sumit.semwal@ti.com> >> >> This patch makes changes for adding dma-contig as a dma_buf user. It >> provides function implementations for the {attach, detach, map, >> unmap}_dmabuf() mem_ops of DMABUF memory type. >> >> Signed-off-by: Sumit Semwal <sumit.semwal@ti.com> >> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org> >> [author of the original patch] >> Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com> >> [integration with refactored dma-contig allocator] >> --- >> drivers/media/video/videobuf2-dma-contig.c | 117 +++++++++++++++++++++++++ >> 1 files changed, 117 insertions(+), 0 deletions(-) >> >> diff --git a/drivers/media/video/videobuf2-dma-contig.c >> b/drivers/media/video/videobuf2-dma-contig.c index 30f316588..6329483 >> 100644 >> --- a/drivers/media/video/videobuf2-dma-contig.c >> +++ b/drivers/media/video/videobuf2-dma-contig.c >> @@ -10,6 +10,7 @@ >> * the Free Software Foundation. >> */ >> >> +#include <linux/dma-buf.h> >> #include <linux/module.h> >> #include <linux/scatterlist.h> >> #include <linux/sched.h> >> @@ -33,6 +34,9 @@ struct vb2_dc_buf { >> >> /* USERPTR related */ >> struct vm_area_struct *vma; >> + >> + /* DMABUF related */ >> + struct dma_buf_attachment *db_attach; >> }; >> >> /*********************************************/ >> @@ -425,6 +429,115 @@ fail_buf: >> } >> >> /*********************************************/ >> +/* callbacks for DMABUF buffers */ >> +/*********************************************/ >> + >> +static int vb2_dc_map_dmabuf(void *mem_priv) >> +{ >> + struct vb2_dc_buf *buf = mem_priv; >> + struct sg_table *sgt; >> + unsigned long contig_size; >> + int ret = 0; >> + >> + if (WARN_ON(!buf->db_attach)) { >> + printk(KERN_ERR "trying to pin a non attached buffer\n"); >> + return -EINVAL; >> + } >> + >> + if (WARN_ON(buf->dma_sgt)) { >> + printk(KERN_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_OR_NULL(sgt)) { >> + printk(KERN_ERR "Error getting dmabuf scatterlist\n"); >> + return -EINVAL; >> + } >> + >> + /* checking if dmabuf is big enough to store contiguous chunk */ >> + contig_size = vb2_dc_get_contiguous_size(sgt); >> + if (contig_size < buf->size) { >> + printk(KERN_ERR "contiguous chunk of dmabuf is too small\n"); >> + ret = -EFAULT; >> + goto fail_map; > > The fail_map label is only used here, you can move the > dma_buf_unmap_attachment() call here and return -EFAULT directly. > Patch "[RFC 07/13] v4l: vb2-dma-contig: change map/unmap behaviour for importers" introduces other cleanup labels. Anyway I will remove this redundant label as you proposed. >> + } >> + >> + buf->dma_addr = sg_dma_address(sgt->sgl); >> + buf->dma_sgt = sgt; >> + >> + return 0; >> + >> +fail_map: >> + dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir); >> + >> + return ret; >> +} >> + >> +static void vb2_dc_unmap_dmabuf(void *mem_priv) >> +{ >> + struct vb2_dc_buf *buf = mem_priv; >> + struct sg_table *sgt = buf->dma_sgt; >> + >> + if (WARN_ON(!buf->db_attach)) { >> + printk(KERN_ERR "trying to unpin a not attached buffer\n"); >> + return; >> + } >> + >> + if (WARN_ON(!sgt)) { >> + printk(KERN_ERR "dmabuf buffer is already unpinned\n"); >> + return; >> + } >> + >> + dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir); >> + >> + buf->dma_addr = 0; >> + buf->dma_sgt = NULL; >> +} >> + >> +static void vb2_dc_detach_dmabuf(void *mem_priv) >> +{ >> + struct vb2_dc_buf *buf = mem_priv; >> + >> + if (buf->dma_addr) >> + vb2_dc_unmap_dmabuf(buf); > > What would you think about calling vb2_dc_unmap_dmabuf() from vb2 core > instead, to keep the map/unmap calls symmetrical (the second WARN_ON and the > related printk in vb2_dc_unmap_dmabuf() might need to go then) ? > Detach without unmap may happen in a case of closing a video fd without prior dequeuing of all buffers. A call map_dmabuf should be moved to __enqueue_in_driver and add calling unmap_dmabuf to vb2_buffer_done in order to keep map/unmap calls symmetrical. I'll check if this could work. Regards, Tomasz Stanislawski
diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c index 30f316588..6329483 100644 --- a/drivers/media/video/videobuf2-dma-contig.c +++ b/drivers/media/video/videobuf2-dma-contig.c @@ -10,6 +10,7 @@ * the Free Software Foundation. */ +#include <linux/dma-buf.h> #include <linux/module.h> #include <linux/scatterlist.h> #include <linux/sched.h> @@ -33,6 +34,9 @@ struct vb2_dc_buf { /* USERPTR related */ struct vm_area_struct *vma; + + /* DMABUF related */ + struct dma_buf_attachment *db_attach; }; /*********************************************/ @@ -425,6 +429,115 @@ fail_buf: } /*********************************************/ +/* callbacks for DMABUF buffers */ +/*********************************************/ + +static int vb2_dc_map_dmabuf(void *mem_priv) +{ + struct vb2_dc_buf *buf = mem_priv; + struct sg_table *sgt; + unsigned long contig_size; + int ret = 0; + + if (WARN_ON(!buf->db_attach)) { + printk(KERN_ERR "trying to pin a non attached buffer\n"); + return -EINVAL; + } + + if (WARN_ON(buf->dma_sgt)) { + printk(KERN_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_OR_NULL(sgt)) { + printk(KERN_ERR "Error getting dmabuf scatterlist\n"); + return -EINVAL; + } + + /* checking if dmabuf is big enough to store contiguous chunk */ + contig_size = vb2_dc_get_contiguous_size(sgt); + if (contig_size < buf->size) { + printk(KERN_ERR "contiguous chunk of dmabuf is too small\n"); + ret = -EFAULT; + goto fail_map; + } + + buf->dma_addr = sg_dma_address(sgt->sgl); + buf->dma_sgt = sgt; + + return 0; + +fail_map: + dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir); + + return ret; +} + +static void vb2_dc_unmap_dmabuf(void *mem_priv) +{ + struct vb2_dc_buf *buf = mem_priv; + struct sg_table *sgt = buf->dma_sgt; + + if (WARN_ON(!buf->db_attach)) { + printk(KERN_ERR "trying to unpin a not attached buffer\n"); + return; + } + + if (WARN_ON(!sgt)) { + printk(KERN_ERR "dmabuf buffer is already unpinned\n"); + return; + } + + dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir); + + buf->dma_addr = 0; + buf->dma_sgt = NULL; +} + +static void vb2_dc_detach_dmabuf(void *mem_priv) +{ + struct vb2_dc_buf *buf = mem_priv; + + if (buf->dma_addr) + vb2_dc_unmap_dmabuf(buf); + + /* detach this attachment */ + dma_buf_detach(buf->db_attach->dmabuf, buf->db_attach); + kfree(buf); +} + +static void *vb2_dc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf, + unsigned long size, int write) +{ + struct vb2_dc_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 = alloc_ctx; + /* create attachment for the dmabuf with the user device */ + dba = dma_buf_attach(dbuf, buf->dev); + if (IS_ERR(dba)) { + printk(KERN_ERR "failed to attach dmabuf\n"); + kfree(buf); + return dba; + } + + buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE; + buf->size = size; + buf->db_attach = dba; + + return buf; +} + +/*********************************************/ /* DMA CONTIG exported functions */ /*********************************************/ @@ -438,6 +551,10 @@ const struct vb2_mem_ops vb2_dma_contig_memops = { .put_userptr = vb2_dc_put_userptr, .prepare = vb2_dc_prepare, .finish = vb2_dc_finish, + .map_dmabuf = vb2_dc_map_dmabuf, + .unmap_dmabuf = vb2_dc_unmap_dmabuf, + .attach_dmabuf = vb2_dc_attach_dmabuf, + .detach_dmabuf = vb2_dc_detach_dmabuf, .num_users = vb2_dc_num_users, }; EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);