linux-toradex.git/drivers/gpu/drm/virtio/virtgpu_object.c, branch v5.12

drm/shmem-helper: Use cached mappings by default

2020-11-24T08:10:21+00:00

SHMEM-buffer backing storage is allocated from system memory; which is
typically cachable. The default mode for SHMEM objects is writecombine
though.

Unify SHMEM semantics by defaulting to cached mappings. The exception
is pages imported via dma-buf. DMA memory is usually not cached.

DRM drivers that require write-combined mappings set the map_wc flag
in struct drm_gem_shmem_object to true. This currently affects lima,
panfrost and v3d.

The drivers mgag200, udl, virtio and vkms continue to use default
shmem mappings.

The drivers cirrus and gm12u320 change caching flags. Both used
writecombine and now switch over to shmem defaults. Both drivers use
SHMEM objects as shadow buffers for internal video memory, so cached
mappings will not affect them negatively.

v3:
	* set value of shmem pointer before dereferencing it in
	  __drm_gem_shmem_create() (Dan, kernel test robot)
v2:
	* recreate patch on top of latest SHMEM helpers
	* update lima, panfrost, v3d to select writecombine (Daniel, Rob)

Signed-off-by: Thomas Zimmermann 
Acked-by: Maxime Ripard 
Link: https://patchwork.freedesktop.org/patch/msgid/20201117133156.26822-2-tzimmermann@suse.de

drm/virtio: use kvmalloc for large allocations

2020-11-05T11:33:26+00:00

We observed that some of virtio_gpu_object_shmem_init() allocations
can be rather costly - order 6 - which can be difficult to fulfill
under memory pressure conditions. Switch to kvmalloc_array() in
virtio_gpu_object_shmem_init() and let the kernel vmalloc the entries
array.

Signed-off-by: Sergey Senozhatsky 
Link: http://patchwork.freedesktop.org/patch/msgid/20201105014744.1662226-1-senozhatsky@chromium.org
Signed-off-by: Gerd Hoffmann

Merge drm/drm-next into drm-misc-next

2020-11-02T10:17:54+00:00

Daniel needs -rc2 in drm-misc-next to merge some patches

Signed-off-by: Maxime Ripard

drm/virtio: implement blob resources: resource create blob ioctl

2020-09-29T09:23:51+00:00

Implement resource create blob as specified.

Signed-off-by: Gerd Hoffmann 
Acked-by: Tomeu Vizoso 
Link: http://patchwork.freedesktop.org/patch/msgid/20200924003214.662-18-gurchetansingh@chromium.org
Co-developed-by: Gurchetan Singh 
Signed-off-by: Gurchetan Singh

drm/virtio: implement blob resources: implement vram object

2020-09-29T09:23:33+00:00

A virtio-gpu vram object is based on range-based allocation.
No guest shmemfs backing, so we call drm_gem_private_object_init.

This is for host memory without any guest backing (atleast initially).

Signed-off-by: Gerd Hoffmann 
Acked-by: Tomeu Vizoso 
Link: http://patchwork.freedesktop.org/patch/msgid/20200924003214.662-12-gurchetansingh@chromium.org
Co-developed-by: Gurchetan Singh 
Signed-off-by: Gurchetan Singh

drm/virtio: implement blob resources: expose virtio_gpu_resource_id_get

2020-09-29T09:23:28+00:00

VRAM object will need it.

Signed-off-by: Gurchetan Singh 
Acked-by: Tomeu Vizoso 
Link: http://patchwork.freedesktop.org/patch/msgid/20200924003214.662-10-gurchetansingh@chromium.org
Signed-off-by: Gerd Hoffmann

drm/virtio: blob prep: refactor getting pages and attaching backing

2020-09-29T09:22:42+00:00

Useful for upcoming blob resources.

Signed-off-by: Gurchetan Singh 
Acked-by: Tomeu Vizoso 
Link: http://patchwork.freedesktop.org/patch/msgid/20200924003214.662-1-gurchetansingh@chromium.org
Signed-off-by: Gerd Hoffmann

drm/virtgpu: Set PRIME export function in struct drm_gem_object_funcs

2020-09-25T07:21:33+00:00

GEM object functions deprecate several similar callback interfaces in
struct drm_driver. This patch replaces virtgpu's per-driver PRIME export
function with a per-object function.

Signed-off-by: Thomas Zimmermann 
Reviewed-by: Daniel Vetter 
Acked-by: Christian König 
Link: https://patchwork.freedesktop.org/patch/msgid/20200923102159.24084-19-tzimmermann@suse.de

Merge branch 'for-5.10-drm-sg-fix' of https://github.com/mszyprow/linux into drm-next

2020-09-17T06:07:11+00:00

Please pull a set of fixes for various DRM drivers that finally resolve
incorrect usage of the scatterlists (struct sg_table nents and orig_nents
entries), what causes issues when IOMMU is used.

Signed-off-by: Dave Airlie 
From: Marek Szyprowski 
Link: https://patchwork.freedesktop.org/patch/msgid/20200910080505.24456-1-m.szyprowski@samsung.com

drm: virtio: fix common struct sg_table related issues

2020-09-10T06:18:35+00:00

The Documentation/DMA-API-HOWTO.txt states that the dma_map_sg() function
returns the number of the created entries in the DMA address space.
However the subsequent calls to the dma_sync_sg_for_{device,cpu}() and
dma_unmap_sg must be called with the original number of the entries
passed to the dma_map_sg().

struct sg_table is a common structure used for describing a non-contiguous
memory buffer, used commonly in the DRM and graphics subsystems. It
consists of a scatterlist with memory pages and DMA addresses (sgl entry),
as well as the number of scatterlist entries: CPU pages (orig_nents entry)
and DMA mapped pages (nents entry).

It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg()
function.

To avoid such issues, lets use a common dma-mapping wrappers operating
directly on the struct sg_table objects and use scatterlist page
iterators where possible. This, almost always, hides references to the
nents and orig_nents entries, making the code robust, easier to follow
and copy/paste safe.

Signed-off-by: Marek Szyprowski 
Acked-by: Gerd Hoffmann