Dan Carpenter has reported that there is the following static checker
warning:
drivers/gpu/drm/drm_prime.c:317 drm_gem_map_dma_buf()
warn: 'sgt' can also be NULL
314 sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
315
316 if (!IS_ERR(sgt)) {
317 if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
Problematic functions are xen_drm_front_gem_get_sg_table and
drm_gem_cma_prime_get_sg_table. Fix those by replacing NULL with error value.
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180719093713.3643-1-andr2000@gmail.com
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Merge tag 'drm-next-2018-06-06-1' of git://anongit.freedesktop.org/drm/drm
Pull drm updates from Dave Airlie:
"This starts to support NVIDIA volta hardware with nouveau, and adds
amdgpu support for the GPU in the Kabylake-G (the intel + radeon
single package chip), along with some initial Intel icelake enabling.
Summary:
New Drivers:
- v3d - driver for broadcom V3D V3.x+ hardware
- xen-front - XEN PV display frontend
core:
- handle zpos normalization in the core
- stop looking at legacy pointers in atomic paths
- improved scheduler documentation
- improved aspect ratio validation
- aspect ratio support for 64:27 and 256:135
- drop unused control node code.
i915:
- Icelake (ICL) enabling
- GuC/HuC refactoring
- PSR/PSR2 enabling and fixes
- DPLL management refactoring
- DP MST fixes
- NV12 enabling
- HDCP improvements
- GEM/Execlist/reset improvements
- GVT improvements
- stolen memory first 4k fix
amdgpu:
- Vega 20 support
- VEGAM support (Kabylake-G)
- preOS scanout buffer reservation
- power management gfxoff support for raven
- SR-IOV fixes
- Vega10 power profiles and clock voltage control
- scatter/gather display support on CZ/ST
amdkfd:
- GFX9 dGPU support
- userptr memory mapping
nouveau:
- major refactoring for Volta GV100 support
tda998x:
- HDMI i2c CEC support
etnaviv:
- removed unused logging code
- license text cleanups
- MMU handling improvements
- timeout fence fix for 50 days uptime
tegra:
- IOMMU support in gr2d/gr3d drivers
- zpos support
vc4:
- syncobj support
- CTM, plane alpha and async cursor support
analogix_dp:
- HPD and aux chan fixes
sun4i:
- MIPI DSI support
tilcdc:
- clock divider fixes for OMAP-l138 LCDK board
rcar-du:
- R8A77965 support
- dma-buf fences fixes
- hardware indexed crtc/du group handling
- generic zplane property support
atmel-hclcdc:
- generic zplane property support
mediatek:
- use generic video mode function
exynos:
- S5PV210 FIMD variant support
- IPP v2 framework
- more HW overlays support"
* tag 'drm-next-2018-06-06-1' of git://anongit.freedesktop.org/drm/drm: (1286 commits)
drm/amdgpu: fix 32-bit build warning
drm/exynos: fimc: signedness bug in fimc_setup_clocks()
drm/exynos: scaler: fix static checker warning
drm/amdgpu: Use dev_info() to report amdkfd is not supported for this ASIC
drm/amd/display: Remove use of division operator for long longs
drm/amdgpu: Update GFX info structure to match what vega20 used
drm/amdgpu/pp: remove duplicate assignment
drm/sched: add rcu_barrier after entity fini
drm/amdgpu: move VM BOs on LRU again
drm/amdgpu: consistenly use VM moved flag
drm/amdgpu: kmap PDs/PTs in amdgpu_vm_update_directories
drm/amdgpu: further optimize amdgpu_vm_handle_moved
drm/amdgpu: cleanup amdgpu_vm_validate_pt_bos v2
drm/amdgpu: rework VM state machine lock handling v2
drm/amdgpu: Add runtime VCN PG support
drm/amdgpu: Enable VCN static PG by default on RV
drm/amdgpu: Add VCN static PG support on RV
drm/amdgpu: Enable VCN CG by default on RV
drm/amdgpu: Add static CG control for VCN on RV
drm/exynos: Fix default value for zpos plane property
...
Building for a 32-bit target results in warnings from casting
between a 32-bit pointer and a 64-bit integer. Fix the warnings
by casting those pointers to uintptr_t first.
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180523113630.29811-1-andr2000@gmail.com
If the loop times out then we want to exit with "to" set to zero, but in
the current code it's set to -1.
Fixes: c575b7eeb8 ("drm/xen-front: Add support for Xen PV display frontend")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180508092829.GC661@mwanda
The xen_drm_front_shbuf_alloc() function was returning a mix of error
pointers and NULL and the the caller wasn't checking correctly. I've
changed it to always return error pointer consistently.
Fixes: c575b7eeb8 ("drm/xen-front: Add support for Xen PV display frontend")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180508092739.GB661@mwanda
It turns out this was only needed to paper over a bug in the CMA
helpers, which was addressed in
commit 998fb1a0f4
Author: Liviu Dudau <Liviu.Dudau@arm.com>
Date: Fri Nov 10 13:33:10 2017 +0000
drm: gem_cma_helper.c: Allow importing of contiguous scatterlists with nents > 1
Without this the following pipeline didn't work:
domU:
1. xen-front allocates a non-contig buffer
2. creates grants out of it
dom0:
3. converts the grants into a dma-buf. Since they're non-contig, the
scatter-list is huge.
4. imports it into rcar-du, which requires dma-contig memory for
scanout.
-> On this given platform there's an IOMMU, so in theory this should
work. But in practice this failed, because of the huge number of sg
entries, even though the IOMMU driver mapped it all into a dma-contig
range.
With a guest-contig buffer allocated in step 1, this problem doesn't
exist. But there's technically no reason to require guest-contig
memory for xen buffer sharing using grants.
Given all that, the xen-front cma support is not needed and should be
removed.
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180417074012.21311-1-andr2000@gmail.com
Add support for Xen para-virtualized frontend display driver.
Accompanying backend [1] is implemented as a user-space application
and its helper library [2], capable of running as a Weston client
or DRM master.
Configuration of both backend and frontend is done via
Xen guest domain configuration options [3].
Driver limitations:
1. Only primary plane without additional properties is supported.
2. Only one video mode supported which resolution is configured
via XenStore.
3. All CRTCs operate at fixed frequency of 60Hz.
1. Implement Xen bus state machine for the frontend driver according to
the state diagram and recovery flow from display para-virtualized
protocol: xen/interface/io/displif.h.
2. Read configuration values from Xen store according
to xen/interface/io/displif.h protocol:
- read connector(s) configuration
- read buffer allocation mode (backend/frontend)
3. Handle Xen event channels:
- create for all configured connectors and publish
corresponding ring references and event channels in Xen store,
so backend can connect
- implement event channels interrupt handlers
- create and destroy event channels with respect to Xen bus state
4. Implement shared buffer handling according to the
para-virtualized display device protocol at xen/interface/io/displif.h:
- handle page directories according to displif protocol:
- allocate and share page directories
- grant references to the required set of pages for the
page directory
- allocate xen balllooned pages via Xen balloon driver
with alloc_xenballooned_pages/free_xenballooned_pages
- grant references to the required set of pages for the
shared buffer itself
- implement pages map/unmap for the buffers allocated by the
backend (gnttab_map_refs/gnttab_unmap_refs)
5. Implement kernel modesetiing/connector handling using
DRM simple KMS helper pipeline:
- implement KMS part of the driver with the help of DRM
simple pipepline helper which is possible due to the fact
that the para-virtualized driver only supports a single
(primary) plane:
- initialize connectors according to XenStore configuration
- handle frame done events from the backend
- create and destroy frame buffers and propagate those
to the backend
- propagate set/reset mode configuration to the backend on display
enable/disable callbacks
- send page flip request to the backend and implement logic for
reporting backend IO errors on prepare fb callback
- implement virtual connector handling:
- support only pixel formats suitable for single plane modes
- make sure the connector is always connected
- support a single video mode as per para-virtualized driver
configuration
6. Implement GEM handling depending on driver mode of operation:
depending on the requirements for the para-virtualized environment,
namely requirements dictated by the accompanying DRM/(v)GPU drivers
running in both host and guest environments, number of operating
modes of para-virtualized display driver are supported:
- display buffers can be allocated by either
frontend driver or backend
- display buffers can be allocated to be contiguous
in memory or not
Note! Frontend driver itself has no dependency on contiguous memory for
its operation.
6.1. Buffers allocated by the frontend driver.
The below modes of operation are configured at compile-time via
frontend driver's kernel configuration.
6.1.1. Front driver configured to use GEM CMA helpers
This use-case is useful when used with accompanying DRM/vGPU driver
in guest domain which was designed to only work with contiguous
buffers, e.g. DRM driver based on GEM CMA helpers: such drivers can
only import contiguous PRIME buffers, thus requiring frontend driver
to provide such. In order to implement this mode of operation
para-virtualized frontend driver can be configured to use
GEM CMA helpers.
6.1.2. Front driver doesn't use GEM CMA
If accompanying drivers can cope with non-contiguous memory then, to
lower pressure on CMA subsystem of the kernel, driver can allocate
buffers from system memory.
Note! If used with accompanying DRM/(v)GPU drivers this mode of operation
may require IOMMU support on the platform, so accompanying DRM/vGPU
hardware can still reach display buffer memory while importing PRIME
buffers from the frontend driver.
6.2. Buffers allocated by the backend
This mode of operation is run-time configured via guest domain
configuration through XenStore entries.
For systems which do not provide IOMMU support, but having specific
requirements for display buffers it is possible to allocate such buffers
at backend side and share those with the frontend.
For example, if host domain is 1:1 mapped and has DRM/GPU hardware
expecting physically contiguous memory, this allows implementing
zero-copying use-cases.
Note, while using this scenario the following should be considered:
a) If guest domain dies then pages/grants received from the backend
cannot be claimed back
b) Misbehaving guest may send too many requests to the
backend exhausting its grant references and memory
(consider this from security POV).
Note! Configuration options 1.1 (contiguous display buffers) and 2
(backend allocated buffers) are not supported at the same time.
7. Handle communication with the backend:
- send requests and wait for the responses according
to the displif protocol
- serialize access to the communication channel
- time-out used for backend communication is set to 3000 ms
- manage display buffers shared with the backend
[1] https://github.com/xen-troops/displ_be
[2] https://github.com/xen-troops/libxenbe
[3] https://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=docs/man/xl.cfg.pod.5.in;h=a699367779e2ae1212ff8f638eff0206ec1a1cc9;hb=refs/heads/master#l1257
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20180403112317.28751-2-andr2000@gmail.com
