On 15/10/2025 17:03, Boris Brezillon wrote: > From: Faith Ekstrand <[email protected]> > > Will be used by the UMD to optimize CPU accesses to buffers > that are frequently read by the CPU, or on which the access > pattern makes non-cacheable mappings inefficient. > > Mapping buffers CPU-cached implies taking care of the CPU > cache maintenance in the UMD, unless the GPU is IO coherent. > > v2: > - Add more to the commit message > > v3: > - No changes > > v4: > - Fix the map_wc test in panfrost_ioctl_query_bo_info() > > Signed-off-by: Faith Ekstrand <[email protected]> > Signed-off-by: Boris Brezillon <[email protected]>
Reviewed-by: Steven Price <[email protected]> > --- > drivers/gpu/drm/panfrost/panfrost_drv.c | 10 ++++++++-- > drivers/gpu/drm/panfrost/panfrost_gem.c | 3 +++ > include/uapi/drm/panfrost_drm.h | 1 + > 3 files changed, 12 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c > b/drivers/gpu/drm/panfrost/panfrost_drv.c > index 00c0881fa2f0..9ca08d148f56 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_drv.c > +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c > @@ -125,6 +125,10 @@ static int panfrost_ioctl_get_param(struct drm_device > *ddev, void *data, struct > return 0; > } > > +#define PANFROST_BO_FLAGS (PANFROST_BO_NOEXEC | \ > + PANFROST_BO_HEAP | \ > + PANFROST_BO_WB_MMAP) > + > static int panfrost_ioctl_create_bo(struct drm_device *dev, void *data, > struct drm_file *file) > { > @@ -134,8 +138,7 @@ static int panfrost_ioctl_create_bo(struct drm_device > *dev, void *data, > struct panfrost_gem_mapping *mapping; > int ret; > > - if (!args->size || args->pad || > - (args->flags & ~(PANFROST_BO_NOEXEC | PANFROST_BO_HEAP))) > + if (!args->size || args->pad || (args->flags & ~PANFROST_BO_FLAGS)) > return -EINVAL; > > /* Heaps should never be executable */ > @@ -661,6 +664,9 @@ static int panfrost_ioctl_query_bo_info(struct drm_device > *dev, void *data, > > if (bo->is_heap) > args->create_flags |= PANFROST_BO_HEAP; > + > + if (!bo->base.map_wc) > + args->create_flags |= PANFROST_BO_WB_MMAP; > } > > drm_gem_object_put(gem_obj); > diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c > b/drivers/gpu/drm/panfrost/panfrost_gem.c > index da0362202d94..0e8028ee9d1f 100644 > --- a/drivers/gpu/drm/panfrost/panfrost_gem.c > +++ b/drivers/gpu/drm/panfrost/panfrost_gem.c > @@ -320,6 +320,9 @@ panfrost_gem_create(struct drm_device *dev, size_t size, > u32 flags) > bo->noexec = !!(flags & PANFROST_BO_NOEXEC); > bo->is_heap = !!(flags & PANFROST_BO_HEAP); > > + if (flags & PANFROST_BO_WB_MMAP) > + bo->base.map_wc = false; > + > return bo; > } > > diff --git a/include/uapi/drm/panfrost_drm.h b/include/uapi/drm/panfrost_drm.h > index e7d01e744efd..244d2f96c2d7 100644 > --- a/include/uapi/drm/panfrost_drm.h > +++ b/include/uapi/drm/panfrost_drm.h > @@ -104,6 +104,7 @@ struct drm_panfrost_wait_bo { > /* Valid flags to pass to drm_panfrost_create_bo */ > #define PANFROST_BO_NOEXEC 1 > #define PANFROST_BO_HEAP 2 > +#define PANFROST_BO_WB_MMAP 4 > > /** > * struct drm_panfrost_create_bo - ioctl argument for creating Panfrost BOs.
