[Lima] [PATCH v7 2/2] drm/lima: driver for ARM Mali4xx GPUs

Wed Mar 6 23:45:55 UTC 2019

On Wed, Mar 6, 2019 at 9:24 AM Qiang Yu <yuq825 at gmail.com> wrote:
>
> - Mali 4xx GPUs have two kinds of processors GP and PP. GP is for
>   OpenGL vertex shader processing and PP is for fragment shader
>   processing. Each processor has its own MMU so prcessors work in
>   virtual address space.
> - There's only one GP but multiple PP (max 4 for mali 400 and 8
>   for mali 450) in the same mali 4xx GPU. All PPs are grouped
>   togather to handle a single fragment shader task divided by
>   FB output tiled pixels. Mali 400 user space driver is
>   responsible for assign target tiled pixels to each PP, but mali
>   450 has a HW module called DLBU to dynamically balance each
>   PP's load.
> - User space driver allocate buffer object and map into GPU
>   virtual address space, upload command stream and draw data with
>   CPU mmap of the buffer object, then submit task to GP/PP with
>   a register frame indicating where is the command stream and misc
>   settings.
> - There's no command stream validation/relocation due to each user
>   process has its own GPU virtual address space. GP/PP's MMU switch
>   virtual address space before running two tasks from different
>   user process. Error or evil user space code just get MMU fault
>   or GP/PP error IRQ, then the HW/SW will be recovered.
> - Use GEM+shmem for MM. Currently just alloc and pin memory when
>   gem object creation. GPU vm map of the buffer is also done in
>   the alloc stage in kernel space. We may delay the memory
>   allocation and real GPU vm map to command submission stage in the
>   furture as improvement.
> - Use drm_sched for GPU task schedule. Each OpenGL context should
>   have a lima context object in the kernel to distinguish tasks
>   from different user. drm_sched gets task from each lima context
>   in a fair way.
>
> mesa driver can be found here before upstreamed:
> https://gitlab.freedesktop.org/lima/mesa
>
> v7:
> - remove lima_fence_ops with default value
> - move fence slab create to device probe
> - check pad ioctl args to be zero
> - add comments for user/kernel interface
>
> v6:
> - fix comments by checkpatch.pl
>
> v5:
> - export gp/pp version to userspace
> - rebase on drm-misc-next
>
> v4:
> - use get param interface to get info
> - separate context create/free ioctl
> - remove unused max sched task param
> - update copyright time
> - use xarray instead of idr
> - stop using drmP.h
>
> v3:
> - fix comments from kbuild robot
> - restrict supported arch to tested ones
>
> v2:
> - fix syscall argument check
> - fix job finish fence leak since kernel 5.0
> - use drm syncobj to replace native fence
> - move buffer object GPU va map into kernel
> - reserve syscall argument space for future info
> - remove kernel gem modifier
> - switch TTM back to GEM+shmem MM
> - use time based io poll
> - use whole register name
> - adopt gem reservation obj integration
> - use drm_timeout_abs_to_jiffies
>
> Cc: Eric Anholt <eric at anholt.net>
> Cc: Rob Herring <robh at kernel.org>
> Cc: Christian König <ckoenig.leichtzumerken at gmail.com>
> Cc: Daniel Vetter <daniel at ffwll.ch>
> Cc: Alex Deucher <alexdeucher at gmail.com>
> Cc: Sam Ravnborg <sam at ravnborg.org>
> Cc: Rob Clark <robdclark at gmail.com>
> Signed-off-by: Andreas Baierl <ichgeh at imkreisrum.de>
> Signed-off-by: Erico Nunes <nunes.erico at gmail.com>
> Signed-off-by: Heiko Stuebner <heiko at sntech.de>
> Signed-off-by: Marek Vasut <marex at denx.de>
> Signed-off-by: Neil Armstrong <narmstrong at baylibre.com>
> Signed-off-by: Simon Shields <simon at lineageos.org>
> Signed-off-by: Vasily Khoruzhick <anarsoul at gmail.com>
> Signed-off-by: Qiang Yu <yuq825 at gmail.com>
> ---
>  drivers/gpu/drm/Kconfig               |   2 +
>  drivers/gpu/drm/Makefile              |   1 +
>  drivers/gpu/drm/lima/Kconfig          |  10 +
>  drivers/gpu/drm/lima/Makefile         |  21 ++
>  drivers/gpu/drm/lima/lima_bcast.c     |  47 +++
>  drivers/gpu/drm/lima/lima_bcast.h     |  14 +
>  drivers/gpu/drm/lima/lima_ctx.c       |  97 ++++++
>  drivers/gpu/drm/lima/lima_ctx.h       |  30 ++
>  drivers/gpu/drm/lima/lima_device.c    | 385 +++++++++++++++++++++++
>  drivers/gpu/drm/lima/lima_device.h    | 131 ++++++++
>  drivers/gpu/drm/lima/lima_dlbu.c      |  58 ++++
>  drivers/gpu/drm/lima/lima_dlbu.h      |  18 ++
>  drivers/gpu/drm/lima/lima_drv.c       | 376 +++++++++++++++++++++++
>  drivers/gpu/drm/lima/lima_drv.h       |  45 +++
>  drivers/gpu/drm/lima/lima_gem.c       | 381 +++++++++++++++++++++++
>  drivers/gpu/drm/lima/lima_gem.h       |  25 ++
>  drivers/gpu/drm/lima/lima_gem_prime.c |  47 +++
>  drivers/gpu/drm/lima/lima_gem_prime.h |  13 +
>  drivers/gpu/drm/lima/lima_gp.c        | 283 +++++++++++++++++
>  drivers/gpu/drm/lima/lima_gp.h        |  16 +
>  drivers/gpu/drm/lima/lima_l2_cache.c  |  80 +++++
>  drivers/gpu/drm/lima/lima_l2_cache.h  |  14 +
>  drivers/gpu/drm/lima/lima_mmu.c       | 142 +++++++++
>  drivers/gpu/drm/lima/lima_mmu.h       |  16 +
>  drivers/gpu/drm/lima/lima_object.c    | 122 ++++++++
>  drivers/gpu/drm/lima/lima_object.h    |  36 +++
>  drivers/gpu/drm/lima/lima_pmu.c       |  60 ++++
>  drivers/gpu/drm/lima/lima_pmu.h       |  12 +
>  drivers/gpu/drm/lima/lima_pp.c        | 427 ++++++++++++++++++++++++++
>  drivers/gpu/drm/lima/lima_pp.h        |  19 ++
>  drivers/gpu/drm/lima/lima_regs.h      | 298 ++++++++++++++++++
>  drivers/gpu/drm/lima/lima_sched.c     | 404 ++++++++++++++++++++++++
>  drivers/gpu/drm/lima/lima_sched.h     | 104 +++++++
>  drivers/gpu/drm/lima/lima_vm.c        | 282 +++++++++++++++++
>  drivers/gpu/drm/lima/lima_vm.h        |  62 ++++
>  include/uapi/drm/lima_drm.h           | 164 ++++++++++
>  36 files changed, 4242 insertions(+)

Reviewed-by: Rob Herring <robh at kerrnel.org>

I can apply this if you want, though I'm not completely sure whether
folks want the mesa bits to go upstream first.

Rob