Re: [Linaro-mm-sig] [PATCH v2] dma-buf: cleanup dma_buf_export() to make it easily extensible

On 28/01/15 06:00, Sumit Semwal wrote:

At present, dma_buf_export() takes a series of parameters, which makes it difficult to add any new parameters for exporters, if required.

Make it simpler by moving all these parameters into a struct, and pass the struct * as parameter to dma_buf_export().

While at it, unite dma_buf_export_named() with dma_buf_export(), and change all callers accordingly.

Signed-off-by: Sumit Semwal sumit.semwal@linaro.org

v2: add macro to zero out local struct, and fill KBUILD_MODNAME by default

drivers/dma-buf/dma-buf.c | 47 +++++++++++++------------- drivers/gpu/drm/armada/armada_gem.c | 10 ++++-- drivers/gpu/drm/drm_prime.c | 12 ++++--- drivers/gpu/drm/exynos/exynos_drm_dmabuf.c | 9 +++-- drivers/gpu/drm/i915/i915_gem_dmabuf.c | 10 ++++-- drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c | 9 ++++- drivers/gpu/drm/tegra/gem.c | 10 ++++-- drivers/gpu/drm/ttm/ttm_object.c | 9 +++-- drivers/gpu/drm/udl/udl_dmabuf.c | 9 ++++- drivers/media/v4l2-core/videobuf2-dma-contig.c | 8 ++++- drivers/media/v4l2-core/videobuf2-dma-sg.c | 8 ++++- drivers/media/v4l2-core/videobuf2-vmalloc.c | 8 ++++- drivers/staging/android/ion/ion.c | 9 +++-- include/linux/dma-buf.h | 35 +++++++++++++++---- 14 files changed, 143 insertions(+), 50 deletions(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 5be225c2ba98..6d3df3dd9310 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -265,7 +265,7 @@ static inline int is_dma_buf_file(struct file *file) } /**

• • dma_buf_export_named - Creates a new dma_buf, and associates an anon file

• • dma_buf_export - Creates a new dma_buf, and associates an anon file
  • with this buffer, so it can be exported.
  • Also connect the allocator specific data and ops to the buffer.
  • Additionally, provide a name string for exporter; useful in debugging.

@@ -277,31 +277,32 @@ static inline int is_dma_buf_file(struct file *file)

• @exp_name: [in] name of the exporting module - useful for debugging.
• @resv: [in] reservation-object, NULL to allocate default one.

• • All the above info comes from struct dma_buf_export_info.
• • Returns, on success, a newly created dma_buf object, which wraps the
  • supplied private data and operations for dma_buf_ops. On either missing
  • ops, or error in allocating struct dma_buf, will return negative error.
  */

-struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops,

• 		size_t size, int flags, const char *exp_name,
  

• 		struct reservation_object *resv)
  

+struct dma_buf *dma_buf_export(struct dma_buf_export_info *exp_info) { struct dma_buf *dmabuf; struct file *file; size_t alloc_size = sizeof(struct dma_buf);

• if (!resv)

• if (!exp_info->resv) alloc_size += sizeof(struct reservation_object); else /* prevent &dma_buf[1] == dma_buf->resv */ alloc_size += 1;

• if (WARN_ON(!priv || !ops

• 	  || !ops->map_dma_buf
  

• 	  || !ops->unmap_dma_buf
  

• 	  || !ops->release
  

• 	  || !ops->kmap_atomic
  

• 	  || !ops->kmap
  

• 	  || !ops->mmap)) {
  

• if (WARN_ON(!exp_info->priv

• 	  || !exp_info->ops
  

• 	  || !exp_info->ops->map_dma_buf
  

• 	  || !exp_info->ops->unmap_dma_buf
  

• 	  || !exp_info->ops->release
  

• 	  || !exp_info->ops->kmap_atomic
  

• 	  || !exp_info->ops->kmap
  

• 	  || !exp_info->ops->mmap)) {
  

  return ERR_PTR(-EINVAL); }

@@ -309,21 +310,22 @@ struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops, if (dmabuf == NULL) return ERR_PTR(-ENOMEM);

• dmabuf->priv = priv;
• dmabuf->ops = ops;
• dmabuf->size = size;
• dmabuf->exp_name = exp_name;

• dmabuf->priv = exp_info->priv;
• dmabuf->ops = exp_info->ops;
• dmabuf->size = exp_info->size;
• dmabuf->exp_name = exp_info->exp_name; init_waitqueue_head(&dmabuf->poll); dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll; dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0;

• if (!resv) {

• resv = (struct reservation_object *)&dmabuf[1];
  

• reservation_object_init(resv);
  

• if (!exp_info->resv) {

• exp_info->resv = (struct reservation_object *)&dmabuf[1];
  

• reservation_object_init(exp_info->resv);
  

  }

• dmabuf->resv = resv;

• dmabuf->resv = exp_info->resv;

• file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf, flags);

• file = anon_inode_getfile("dmabuf", &dma_buf_fops, dmabuf,

• 			exp_info->flags);
  

  if (IS_ERR(file)) { kfree(dmabuf); return ERR_CAST(file);

@@ -341,8 +343,7 @@ struct dma_buf *dma_buf_export_named(void *priv, const struct dma_buf_ops *ops, return dmabuf; } -EXPORT_SYMBOL_GPL(dma_buf_export_named);

+EXPORT_SYMBOL_GPL(dma_buf_export); /**

• dma_buf_fd - returns a file descriptor for the given dma_buf

diff --git a/drivers/gpu/drm/armada/armada_gem.c b/drivers/gpu/drm/armada/armada_gem.c index ef5feeecec84..580e10acaa3a 100644 --- a/drivers/gpu/drm/armada/armada_gem.c +++ b/drivers/gpu/drm/armada/armada_gem.c @@ -538,8 +538,14 @@ struct dma_buf * armada_gem_prime_export(struct drm_device *dev, struct drm_gem_object *obj, int flags) {

• return dma_buf_export(obj, &armada_gem_prime_dmabuf_ops, obj->size,

• 	      O_RDWR, NULL);
  

• DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
• exp_info.ops = &armada_gem_prime_dmabuf_ops;
• exp_info.size = obj->size;
• exp_info.flags = O_RDWR;
• exp_info.priv = obj;
• return dma_buf_export(&exp_info);

} struct drm_gem_object * diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c index 7482b06cd08f..7fec191b45f7 100644 --- a/drivers/gpu/drm/drm_prime.c +++ b/drivers/gpu/drm/drm_prime.c @@ -339,13 +339,17 @@ static const struct dma_buf_ops drm_gem_prime_dmabuf_ops = { struct dma_buf *drm_gem_prime_export(struct drm_device *dev, struct drm_gem_object *obj, int flags) {

• struct reservation_object *robj = NULL;

• DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
• exp_info.ops = &drm_gem_prime_dmabuf_ops;
• exp_info.size = obj->size;
• exp_info.flags = flags;
• exp_info.priv = obj;

if (dev->driver->gem_prime_res_obj)

• robj = dev->driver->gem_prime_res_obj(obj);
  

• exp_info.resv = dev->driver->gem_prime_res_obj(obj);
  

• return dma_buf_export(obj, &drm_gem_prime_dmabuf_ops, obj->size,

• 	      flags, robj);
  

• return dma_buf_export(&exp_info);

} EXPORT_SYMBOL(drm_gem_prime_export); diff --git a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c index 60192ed544f0..fc293a179f36 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c +++ b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c @@ -185,9 +185,14 @@ struct dma_buf *exynos_dmabuf_prime_export(struct drm_device *drm_dev, struct drm_gem_object *obj, int flags) { struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);

• DEFINE_DMA_BUF_EXPORT_INFO(exp_info);

• return dma_buf_export(obj, &exynos_dmabuf_ops,

• 		exynos_gem_obj->base.size, flags, NULL);
  

• exp_info.ops = &exynos_dmabuf_ops;
• exp_info.size = exynos_gem_obj->base.size;
• exp_info.flags = flags;
• exp_info.priv = obj;
• return dma_buf_export(&exp_info);

} struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev, diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c index 82a1f4b57778..7998da27c500 100644 --- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c +++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c @@ -230,6 +230,13 @@ struct dma_buf *i915_gem_prime_export(struct drm_device *dev, struct drm_gem_object *gem_obj, int flags) { struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);

• DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
• exp_info.ops = &i915_dmabuf_ops;
• exp_info.size = gem_obj->size;
• exp_info.flags = flags;
• exp_info.priv = gem_obj;

if (obj->ops->dmabuf_export) { int ret = obj->ops->dmabuf_export(obj); @@ -237,8 +244,7 @@ struct dma_buf *i915_gem_prime_export(struct drm_device *dev, return ERR_PTR(ret); }

• return dma_buf_export(gem_obj, &i915_dmabuf_ops, gem_obj->size, flags,

• 	      NULL);
  

• return dma_buf_export(&exp_info);

} static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj) diff --git a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c index a2dbfb1737b4..5874c58e72c1 100644 --- a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c +++ b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c @@ -171,7 +171,14 @@ static struct dma_buf_ops omap_dmabuf_ops = { struct dma_buf *omap_gem_prime_export(struct drm_device *dev, struct drm_gem_object *obj, int flags) {

• return dma_buf_export(obj, &omap_dmabuf_ops, obj->size, flags, NULL);

• DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
• exp_info.ops = &omap_dmabuf_ops;
• exp_info.size = obj->size;
• exp_info.flags = flags;
• exp_info.priv = obj;
• return dma_buf_export(&exp_info);

} struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev, diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c index 8777b7f75791..1f895b953f8f 100644 --- a/drivers/gpu/drm/tegra/gem.c +++ b/drivers/gpu/drm/tegra/gem.c @@ -658,8 +658,14 @@ struct dma_buf *tegra_gem_prime_export(struct drm_device *drm, struct drm_gem_object *gem, int flags) {

• return dma_buf_export(gem, &tegra_gem_prime_dmabuf_ops, gem->size,

• 	      flags, NULL);
  

• DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
• exp_info.ops = &tegra_gem_prime_dmabuf_ops;
• exp_info.size = gem->size;
• exp_info.flags = flags;
• exp_info.priv = gem;
• return dma_buf_export(&exp_info);

} struct drm_gem_object *tegra_gem_prime_import(struct drm_device *drm, diff --git a/drivers/gpu/drm/ttm/ttm_object.c b/drivers/gpu/drm/ttm/ttm_object.c index 12c87110db3a..4f5fa8d65fe9 100644 --- a/drivers/gpu/drm/ttm/ttm_object.c +++ b/drivers/gpu/drm/ttm/ttm_object.c @@ -683,6 +683,12 @@ int ttm_prime_handle_to_fd(struct ttm_object_file *tfile, dma_buf = prime->dma_buf; if (!dma_buf || !get_dma_buf_unless_doomed(dma_buf)) {

• DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
  

• exp_info.ops = &tdev->ops;
  

• exp_info.size = prime->size;
  

• exp_info.flags = flags;
  

• exp_info.priv = prime;
  

/* * Need to create a new dma_buf, with memory accounting. @@ -694,8 +700,7 @@ int ttm_prime_handle_to_fd(struct ttm_object_file *tfile, goto out_unref; }

• dma_buf = dma_buf_export(prime, &tdev->ops,
  

• 			 prime->size, flags, NULL);
  

• dma_buf = dma_buf_export(&exp_info);
  

  if (IS_ERR(dma_buf)) { ret = PTR_ERR(dma_buf); ttm_mem_global_free(tdev->mem_glob,

diff --git a/drivers/gpu/drm/udl/udl_dmabuf.c b/drivers/gpu/drm/udl/udl_dmabuf.c index ac8a66b4dfc2..e2243edd1ce3 100644 --- a/drivers/gpu/drm/udl/udl_dmabuf.c +++ b/drivers/gpu/drm/udl/udl_dmabuf.c @@ -202,7 +202,14 @@ static struct dma_buf_ops udl_dmabuf_ops = { struct dma_buf *udl_gem_prime_export(struct drm_device *dev, struct drm_gem_object *obj, int flags) {

• return dma_buf_export(obj, &udl_dmabuf_ops, obj->size, flags, NULL);

• DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
• exp_info.ops = &udl_dmabuf_ops;
• exp_info.size = obj->size;
• exp_info.flags = flags;
• exp_info.priv = obj;
• return dma_buf_export(&exp_info);

} static int udl_prime_create(struct drm_device *dev, diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c index b481d20c8372..4ad92a147919 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-contig.c +++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c @@ -402,6 +402,12 @@ static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv, unsigned long flags) { struct vb2_dc_buf *buf = buf_priv; struct dma_buf *dbuf;

• DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
• exp_info.ops = &vb2_dc_dmabuf_ops;
• exp_info.size = buf->size;
• exp_info.flags = flags;
• exp_info.priv = buf;

if (!buf->sgt_base) buf->sgt_base = vb2_dc_get_base_sgt(buf); @@ -409,7 +415,7 @@ static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv, unsigned long flags) if (WARN_ON(!buf->sgt_base)) return NULL;

• dbuf = dma_buf_export(buf, &vb2_dc_dmabuf_ops, buf->size, flags, NULL);

• dbuf = dma_buf_export(&exp_info); if (IS_ERR(dbuf)) return NULL;

diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c index b1838abb6d00..45c708e463b9 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-sg.c +++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c @@ -583,11 +583,17 @@ 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;

• 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(buf, &vb2_dma_sg_dmabuf_ops, buf->size, flags, NULL);

• dbuf = dma_buf_export(&exp_info); if (IS_ERR(dbuf)) return NULL;

diff --git a/drivers/media/v4l2-core/videobuf2-vmalloc.c b/drivers/media/v4l2-core/videobuf2-vmalloc.c index fba944e50227..992b1b59409c 100644 --- a/drivers/media/v4l2-core/videobuf2-vmalloc.c +++ b/drivers/media/v4l2-core/videobuf2-vmalloc.c @@ -367,11 +367,17 @@ static struct dma_buf *vb2_vmalloc_get_dmabuf(void *buf_priv, unsigned long flag { struct vb2_vmalloc_buf *buf = buf_priv; struct dma_buf *dbuf;

• DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
• exp_info.ops = &vb2_vmalloc_dmabuf_ops;
• exp_info.size = buf->size;
• exp_info.flags = flags;
• exp_info.priv = buf;

if (WARN_ON(!buf->vaddr)) return NULL;

• dbuf = dma_buf_export(buf, &vb2_vmalloc_dmabuf_ops, buf->size, flags, NULL);

• dbuf = dma_buf_export(&exp_info); if (IS_ERR(dbuf)) return NULL;

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index 296d347660fc..a4297be8f12f 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -1106,6 +1106,12 @@ struct dma_buf *ion_share_dma_buf(struct ion_client *client, struct ion_buffer *buffer; struct dma_buf *dmabuf; bool valid_handle;

• DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
• exp_info.ops = &dma_buf_ops;
• exp_info.size = buffer->size;
• exp_info.flags = O_RDWR;
• exp_info.priv = buffer;

mutex_lock(&client->lock); valid_handle = ion_handle_validate(client, handle); @@ -1118,8 +1124,7 @@ struct dma_buf *ion_share_dma_buf(struct ion_client *client, ion_buffer_get(buffer); mutex_unlock(&client->lock);

• dmabuf = dma_buf_export(buffer, &dma_buf_ops, buffer->size, O_RDWR,

• 		NULL);
  

• dmabuf = dma_buf_export(&exp_info); if (IS_ERR(dmabuf)) { ion_buffer_put(buffer); return dmabuf;

diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 694e1fe1c4b4..22c21a224e32 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -163,6 +163,34 @@ struct dma_buf_attachment { }; /**

• • struct dma_buf_export_info - holds information needed to export a dma_buf
• • @exp_name: name of the exporting module - useful for debugging.
• • @ops: Attach allocator-defined dma buf ops to the new buffer
• • @size: Size of the buffer
• • @flags: mode flags for the file
• • @resv: reservation-object, NULL to allocate default one
• • @priv: Attach private data of allocator to this buffer
• • This structure holds the information required to export the buffer. Used
• • with dma_buf_export() only.
• */

+struct dma_buf_export_info {

• const char *exp_name;
• const struct dma_buf_ops *ops;
• size_t size;
• int flags;
• struct reservation_object *resv;
• void *priv;

+};

+/**

• • helper macro for exporters; zeros and fills in most common values
• */

+#define DEFINE_DMA_BUF_EXPORT_INFO(a) \

• struct dma_buf_export_info a = {0}; \
• exp_info.exp_name = KBUILD_MODNAME

This risks generating C99 warnings unless used with care (and only once per function). Shouldn't this be more like:

#define DEFINE_DMA_BUF_EXPORT_INFO(a) \ struct dma_buf_export_info a = { .exp_name = KBUILD_MODNAME }

Daniel.