On Fri, 2019-08-02 at 19:29 +0200, Lucas Stach wrote:
With softpin we allow the userspace to take control over the GPU virtual address space. The new capability is relected by a bump of the minor DRM version. There are a few restrictions for userspace to take into account:
- The kernel reserves a bit of the address space to implement zero page
faulting and mapping of the kernel internal ring buffer. Userspace can query the kernel for the first usable GPU VM address via ETNAVIV_PARAM_SOFTPIN_START_ADDR.
- We only allow softpin on GPUs, which implement proper process
separation via PPAS. If softpin is not available the softpin start address will be set to ~0.
- Softpin is all or nothing. A submit using softpin must not use any
address fixups via relocs.
Signed-off-by: Lucas Stach l.stach@pengutronix.de
drivers/gpu/drm/etnaviv/etnaviv_drv.c | 2 +- drivers/gpu/drm/etnaviv/etnaviv_drv.h | 2 ++ drivers/gpu/drm/etnaviv/etnaviv_gem.c | 4 ++-- drivers/gpu/drm/etnaviv/etnaviv_gem.h | 1 + drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c | 25 +++++++++++++++++++- drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 9 +++++++ include/uapi/drm/etnaviv_drm.h | 5 +++- 7 files changed, 43 insertions(+), 5 deletions(-)
[...]
diff --git a/include/uapi/drm/etnaviv_drm.h b/include/uapi/drm/etnaviv_drm.h index 0d5c49dc478c..c5710485650c 100644 --- a/include/uapi/drm/etnaviv_drm.h +++ b/include/uapi/drm/etnaviv_drm.h @@ -73,6 +73,7 @@ struct drm_etnaviv_timespec { #define ETNAVIV_PARAM_GPU_INSTRUCTION_COUNT 0x18 #define ETNAVIV_PARAM_GPU_NUM_CONSTANTS 0x19 #define ETNAVIV_PARAM_GPU_NUM_VARYINGS 0x1a +#define ETNAVIV_PARAM_SOFTPIN_START_ADDR 0x1b
#define ETNA_MAX_PIPES 4
@@ -177,9 +178,11 @@ struct drm_etnaviv_gem_submit_pmr { #define ETNA_SUBMIT_NO_IMPLICIT 0x0001 #define ETNA_SUBMIT_FENCE_FD_IN 0x0002 #define ETNA_SUBMIT_FENCE_FD_OUT 0x0004 +#define ETNA_SUBMIT_SOFTPIN 0x0008 #define ETNA_SUBMIT_FLAGS (ETNA_SUBMIT_NO_IMPLICIT | \ ETNA_SUBMIT_FENCE_FD_IN | \
ETNA_SUBMIT_FENCE_FD_OUT)
ETNA_SUBMIT_FENCE_FD_OUT| \ETNA_SUBMIT_SOFTPIN)#define ETNA_PIPE_3D 0x00 #define ETNA_PIPE_2D 0x01 #define ETNA_PIPE_VG 0x02
The presumed field of drm_etnaviv_gem_submit_bo has an elaborate comment on its supposed pre-softpin use in etnaviv_drm.h, maybe that should be updated.
Otherwise,
Reviewed-by: Philipp Zabel p.zabel@pengutronix.de
regards Philipp