On 06/18/2013 04:08 PM, Laurent Pinchart wrote: > Hi Aaron, > > A bit late, but here's a small question. > > On Tuesday 15 January 2013 12:47:42 Aaron Plattner wrote: >> Instead of reimplementing all of the dma_buf functionality in every driver, >> create helpers drm_prime_import and drm_prime_export that implement them in >> terms of new, lower-level hook functions: >> >> gem_prime_pin: callback when a buffer is created, used to pin buffers into >> GTT gem_prime_get_sg_table: convert a drm_gem_object to an sg_table for >> export gem_prime_import_sg_table: convert an sg_table into a drm_gem_object >> gem_prime_vmap, gem_prime_vunmap: map and unmap an object >> >> These hooks are optional; drivers can opt in by using drm_gem_prime_import >> and drm_gem_prime_export as the .gem_prime_import and .gem_prime_export >> fields of struct drm_driver. >> >> v2: >> - Drop .begin_cpu_access. None of the drivers this code replaces >> implemented it. Having it here was a leftover from when I was trying to >> include i915 in this rework. >> - Use mutex_lock instead of mutex_lock_interruptible, as these three drivers >> did. This patch series shouldn't change that behavior. >> - Rename helpers to gem_prime_get_sg_table and gem_prime_import_sg_table. >> Rename struct sg_table* variables to 'sgt' for clarity. >> - Update drm.tmpl for these new hooks. >> >> v3: >> - Pass the vaddr down to the driver. This lets drivers that just call >> vunmap on the pointer avoid having to store the pointer in their GEM >> private structures. - Move documentation into a /** DOC */ comment in >> drm_prime.c and include it in drm.tmpl with a !P line. I tried to use !F >> lines to include documentation of the individual functions from drmP.h, but >> the docproc / kernel-doc scripts barf on that file, so hopefully this is >> good enough for now. >> - apply refcount fix from commit be8a42ae60addd8b6092535c11b42d099d6470ec >> ("drm/prime: drop reference on imported dma-buf come from gem") >> >> Signed-off-by: Aaron Plattner <aplattner at nvidia.com> >> Cc: Daniel Vetter <daniel.vetter at ffwll.ch> >> Cc: David Airlie <airlied at linux.ie> >> --- >> Documentation/DocBook/drm.tmpl | 4 + >> drivers/gpu/drm/drm_prime.c | 186 +++++++++++++++++++++++++++++++++++++- >> include/drm/drmP.h | 12 +++ >> 3 files changed, 201 insertions(+), 1 deletion(-) > > [snip] > >> diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c >> index 7f12573..366910d 100644 >> --- a/drivers/gpu/drm/drm_prime.c >> +++ b/drivers/gpu/drm/drm_prime.c > > [snip] > >> +/** >> + * DOC: PRIME Helpers >> + * >> + * Drivers can implement @gem_prime_export and @gem_prime_import in terms >> of + * simpler APIs by using the helper functions @drm_gem_prime_export and >> + * @drm_gem_prime_import. These functions implement dma-buf support in >> terms of + * five lower-level driver callbacks: >> + * >> + * Export callbacks: >> + * >> + * - @gem_prime_pin (optional): prepare a GEM object for exporting >> + * >> + * - @gem_prime_get_sg_table: provide a scatter/gather table of pinned >> pages + * >> + * - @gem_prime_vmap: vmap a buffer exported by your driver >> + * >> + * - @gem_prime_vunmap: vunmap a buffer exported by your driver >> + * >> + * Import callback: >> + * >> + * - @gem_prime_import_sg_table (import): produce a GEM object from >> another + * driver's scatter/gather table >> + */ >> + >> +struct dma_buf *drm_gem_prime_export(struct drm_device *dev, >> + struct drm_gem_object *obj, int flags) >> +{ >> + if (dev->driver->gem_prime_pin) { >> + int ret = dev->driver->gem_prime_pin(obj); >> + if (ret) >> + return ERR_PTR(ret); >> + } >> + return dma_buf_export(obj, &drm_gem_prime_dmabuf_ops, obj->size, >> + 0600); > > Why do you use 0600 instead of the flags passed by the caller ?
Because I copied & pasted it from i915_gem_prime_export prior to commit 5b42427fc38ecb9056c4e64deaff36d6d6ba1b67 and didn't notice until you pointed it out just now. >> +} >> +EXPORT_SYMBOL(drm_gem_prime_export); -- Aaron