Having the support for vmapping dmabuf's is required to share dmabufs to drivers that want CPU access. This is the case of a vivid to virtio-gpu pipeline, where the virtio-gpu driver exports dmabufs to the video4linux vivid driver.
The first patch adds virtio_gpu_object_kunmap() and calls it from the TTM object destroy path. This function will be used to unmap prime objects.
The second patch reworks virtio_gpu_object_kmap(), so it's balanced with virtio_gpu_object_kunmap.
Finally, the third patch uses virtio_gpu_object_k{map,unmap} to support prime v{map,unmap}.
Please review!
Ezequiel Garcia (3): virtio: Add virtio_gpu_object_kunmap() virtio: Rework virtio_gpu_object_kmap() virtio: Support prime objects vmap/vunmap
drivers/gpu/drm/virtio/virtgpu_drv.h | 3 ++- drivers/gpu/drm/virtio/virtgpu_fb.c | 10 ++-------- drivers/gpu/drm/virtio/virtgpu_object.c | 19 +++++++++++-------- drivers/gpu/drm/virtio/virtgpu_prime.c | 11 ++++++++--- 4 files changed, 23 insertions(+), 20 deletions(-)
Implement a virtio_gpu_object_kunmap() to unmap the kernel mapping, and use it in the TTM object destroy path.
Signed-off-by: Ezequiel Garcia ezequiel@collabora.com --- drivers/gpu/drm/virtio/virtgpu_drv.h | 1 + drivers/gpu/drm/virtio/virtgpu_object.c | 8 ++++++++ 2 files changed, 9 insertions(+)
diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h index 2de29c90bed2..a8af46570a01 100644 --- a/drivers/gpu/drm/virtio/virtgpu_drv.h +++ b/drivers/gpu/drm/virtio/virtgpu_drv.h @@ -356,6 +356,7 @@ void virtio_gpu_fence_event_process(struct virtio_gpu_device *vdev, int virtio_gpu_object_create(struct virtio_gpu_device *vgdev, unsigned long size, bool kernel, bool pinned, struct virtio_gpu_object **bo_ptr); +void virtio_gpu_object_kunmap(struct virtio_gpu_object *bo); int virtio_gpu_object_kmap(struct virtio_gpu_object *bo, void **ptr); int virtio_gpu_object_get_sg_table(struct virtio_gpu_device *qdev, struct virtio_gpu_object *bo); diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c index 9f2f470efd9b..113eae00d293 100644 --- a/drivers/gpu/drm/virtio/virtgpu_object.c +++ b/drivers/gpu/drm/virtio/virtgpu_object.c @@ -37,6 +37,8 @@ static void virtio_gpu_ttm_bo_destroy(struct ttm_buffer_object *tbo) virtio_gpu_cmd_unref_resource(vgdev, bo->hw_res_handle); if (bo->pages) virtio_gpu_object_free_sg_table(bo); + if (bo->vmap) + virtio_gpu_object_kunmap(bo); drm_gem_object_release(&bo->gem_base); kfree(bo); } @@ -99,6 +101,12 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev, return 0; }
+void virtio_gpu_object_kunmap(struct virtio_gpu_object *bo) +{ + bo->vmap = NULL; + ttm_bo_kunmap(&bo->kmap); +} + int virtio_gpu_object_kmap(struct virtio_gpu_object *bo, void **ptr) { bool is_iomem;
Currently, virtio_gpu_object_kmap() is only called by virtio_gpufb_create(), when a DRM framebuffer is created.
Thus, instead of returning the vmap'ed address, emit a warning if virtio_gpu_object_kmap is called on an already mapped object. With this change, kmap/kunmap calls are now balanced.
Signed-off-by: Ezequiel Garcia ezequiel@collabora.com --- drivers/gpu/drm/virtio/virtgpu_drv.h | 2 +- drivers/gpu/drm/virtio/virtgpu_fb.c | 10 ++-------- drivers/gpu/drm/virtio/virtgpu_object.c | 11 +++-------- 3 files changed, 6 insertions(+), 17 deletions(-)
diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h index a8af46570a01..97f366f5d2ea 100644 --- a/drivers/gpu/drm/virtio/virtgpu_drv.h +++ b/drivers/gpu/drm/virtio/virtgpu_drv.h @@ -357,7 +357,7 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev, unsigned long size, bool kernel, bool pinned, struct virtio_gpu_object **bo_ptr); void virtio_gpu_object_kunmap(struct virtio_gpu_object *bo); -int virtio_gpu_object_kmap(struct virtio_gpu_object *bo, void **ptr); +int virtio_gpu_object_kmap(struct virtio_gpu_object *bo); int virtio_gpu_object_get_sg_table(struct virtio_gpu_device *qdev, struct virtio_gpu_object *bo); void virtio_gpu_object_free_sg_table(struct virtio_gpu_object *bo); diff --git a/drivers/gpu/drm/virtio/virtgpu_fb.c b/drivers/gpu/drm/virtio/virtgpu_fb.c index b5cebc9a179a..08ab43b91509 100644 --- a/drivers/gpu/drm/virtio/virtgpu_fb.c +++ b/drivers/gpu/drm/virtio/virtgpu_fb.c @@ -210,12 +210,6 @@ static struct fb_ops virtio_gpufb_ops = { .fb_imageblit = virtio_gpu_3d_imageblit, };
-static int virtio_gpu_vmap_fb(struct virtio_gpu_device *vgdev, - struct virtio_gpu_object *obj) -{ - return virtio_gpu_object_kmap(obj, NULL); -} - static int virtio_gpufb_create(struct drm_fb_helper *helper, struct drm_fb_helper_surface_size *sizes) { @@ -248,9 +242,9 @@ static int virtio_gpufb_create(struct drm_fb_helper *helper, virtio_gpu_cmd_create_resource(vgdev, resid, format, mode_cmd.width, mode_cmd.height);
- ret = virtio_gpu_vmap_fb(vgdev, obj); + ret = virtio_gpu_object_kmap(obj); if (ret) { - DRM_ERROR("failed to vmap fb %d\n", ret); + DRM_ERROR("failed to kmap fb %d\n", ret); goto err_obj_vmap; }
diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c index 113eae00d293..eca765537470 100644 --- a/drivers/gpu/drm/virtio/virtgpu_object.c +++ b/drivers/gpu/drm/virtio/virtgpu_object.c @@ -107,22 +107,17 @@ void virtio_gpu_object_kunmap(struct virtio_gpu_object *bo) ttm_bo_kunmap(&bo->kmap); }
-int virtio_gpu_object_kmap(struct virtio_gpu_object *bo, void **ptr) +int virtio_gpu_object_kmap(struct virtio_gpu_object *bo) { bool is_iomem; int r;
- if (bo->vmap) { - if (ptr) - *ptr = bo->vmap; - return 0; - } + WARN_ON(bo->vmap); + r = ttm_bo_kmap(&bo->tbo, 0, bo->tbo.num_pages, &bo->kmap); if (r) return r; bo->vmap = ttm_kmap_obj_virtual(&bo->kmap, &is_iomem); - if (ptr) - *ptr = bo->vmap; return 0; }
Implement vmap/vunmap so we can export dmabufs to other drivers, such as video4linux.
Tested with a virtio-gpu / vivid (virtual capture driver) pipeline, where the vivid driver imports the dmabufs exported by virtio-gpu.
Note that dma_buf_vmap() does its own vmap counting, so it's not needed to take care of it in the driver.
Signed-off-by: Ezequiel Garcia ezequiel@collabora.com --- drivers/gpu/drm/virtio/virtgpu_prime.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/virtio/virtgpu_prime.c b/drivers/gpu/drm/virtio/virtgpu_prime.c index d27a1688714f..86ce0ae93f59 100644 --- a/drivers/gpu/drm/virtio/virtgpu_prime.c +++ b/drivers/gpu/drm/virtio/virtgpu_prime.c @@ -55,13 +55,18 @@ struct drm_gem_object *virtgpu_gem_prime_import_sg_table(
void *virtgpu_gem_prime_vmap(struct drm_gem_object *obj) { - WARN_ONCE(1, "not implemented"); - return ERR_PTR(-ENODEV); + struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj); + int ret; + + ret = virtio_gpu_object_kmap(bo); + if (ret) + return NULL; + return bo->vmap; }
void virtgpu_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr) { - WARN_ONCE(1, "not implemented"); + virtio_gpu_object_kunmap(gem_to_virtio_gpu_obj(obj)); }
int virtgpu_gem_prime_mmap(struct drm_gem_object *obj,
Hi,
Having the support for vmapping dmabuf's is required to share dmabufs to drivers that want CPU access. This is the case of a vivid to virtio-gpu pipeline, where the virtio-gpu driver exports dmabufs to the video4linux vivid driver.
The first patch adds virtio_gpu_object_kunmap() and calls it from the TTM object destroy path. This function will be used to unmap prime objects.
The second patch reworks virtio_gpu_object_kmap(), so it's balanced with virtio_gpu_object_kunmap.
Finally, the third patch uses virtio_gpu_object_k{map,unmap} to support prime v{map,unmap}.
Please review!
Pushed to drm-misc-next.
thanks, Gerd
dri-devel@lists.freedesktop.org
-
Ezequiel Garcia -
Gerd Hoffmann