Commit b7a0e756 authored by Jacek Lawrynowicz's avatar Jacek Lawrynowicz
Browse files

accel/ivpu: Disable buffer sharing among VPU contexts 



This was not supported properly. A buffer was imported to another VPU
context as a separate buffer object with duplicated sgt.
Both exported and imported buffers could be DMA mapped causing a double
mapping on the same device.

Buffers imported from another VPU context will now just increase
reference count, leaving only a single sgt, fixing the problem above.
Buffers still can't be shared among VPU contexts because each has its
own MMU mapping and ivpu_bo only supports single MMU mappings.

The solution would be to use a mapping list as in panfrost or etnaviv
drivers and it will be implemented in future if required.

Signed-off-by: default avatarJacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Reviewed-by: default avatarAndrzej Kacprowski <andrzej.kacprowski@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240115134434.493839-8-jacek.lawrynowicz@linux.intel.com
parent a8c099d5

drivers/accel/ivpu/ivpu_gem.c

+6 −38
Original line number Diff line number Diff line
@@ -222,6 +222,12 @@ static int ivpu_bo_open(struct drm_gem_object *obj, struct drm_file *file) 
	struct ivpu_bo *bo = to_ivpu_bo(obj);

	struct ivpu_addr_range *range;



	if (bo->ctx) {

		ivpu_warn(vdev, "Can't add BO to ctx %u: already in ctx %u\n",

			  file_priv->ctx.id, bo->ctx->id);

		return -EALREADY;

	}



	if (bo->flags & DRM_IVPU_BO_SHAVE_MEM)

		range = &vdev->hw->ranges.shave;

	else if (bo->flags & DRM_IVPU_BO_DMA_MEM)
@@ -252,47 +258,9 @@ static void ivpu_bo_free(struct drm_gem_object *obj) 
	drm_gem_shmem_free(&bo->base);

}



static const struct dma_buf_ops ivpu_bo_dmabuf_ops =  {

	.cache_sgt_mapping = true,

	.attach = drm_gem_map_attach,

	.detach = drm_gem_map_detach,

	.map_dma_buf = drm_gem_map_dma_buf,

	.unmap_dma_buf = drm_gem_unmap_dma_buf,

	.release = drm_gem_dmabuf_release,

	.mmap = drm_gem_dmabuf_mmap,

	.vmap = drm_gem_dmabuf_vmap,

	.vunmap = drm_gem_dmabuf_vunmap,

};



static struct dma_buf *ivpu_bo_export(struct drm_gem_object *obj, int flags)

{

	struct drm_device *dev = obj->dev;

	struct dma_buf_export_info exp_info = {

		.exp_name = KBUILD_MODNAME,

		.owner = dev->driver->fops->owner,

		.ops = &ivpu_bo_dmabuf_ops,

		.size = obj->size,

		.flags = flags,

		.priv = obj,

		.resv = obj->resv,

	};

	void *sgt;



	/*

	 * Make sure that pages are allocated and dma-mapped before exporting the bo.

	 * DMA-mapping is required if the bo will be imported to the same device.

	 */

	sgt = drm_gem_shmem_get_pages_sgt(to_drm_gem_shmem_obj(obj));

	if (IS_ERR(sgt))

		return sgt;



	return drm_gem_dmabuf_export(dev, &exp_info);

}



static const struct drm_gem_object_funcs ivpu_gem_funcs = {

	.free = ivpu_bo_free,

	.open = ivpu_bo_open,

	.export = ivpu_bo_export,

	.print_info = drm_gem_shmem_object_print_info,

	.pin = drm_gem_shmem_object_pin,

	.unpin = drm_gem_shmem_object_unpin,