On Thu, 1 Jul 2021 at 16:10, Matthew Auld matthew.auld@intel.com wrote:
The CPU domain should be static for discrete, and on DG1 we don't need any flushing since everything is already coherent, so really all this does is an object wait, for which we have an ioctl. Longer term the desired caching should be an immutable creation time property for the BO, which can be set with something like gem_create_ext.
One other user is iris + userptr, which uses the set_domain to probe all the pages to check if the GUP succeeds, however keeping the set_domain around just for that seems rather scuffed. We could equally just submit a dummy batch, which should hopefully be good enough, otherwise adding a new creation time flag for userptr might be an option. Although longer term we will also have vm_bind, which should also be a nice fit for this, so adding a whole new flag is likely overkill.
Kenneth, do you have a preference for the iris + userptr use case? Adding the flag shouldn't be much work, if you feel the dummy batch is too ugly. I don't mind either way.
Suggested-by: Daniel Vetter daniel@ffwll.ch Signed-off-by: Matthew Auld matthew.auld@intel.com Cc: Thomas Hellström thomas.hellstrom@linux.intel.com Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Jordan Justen jordan.l.justen@intel.com Cc: Kenneth Graunke kenneth@whitecape.org Cc: Jason Ekstrand jason@jlekstrand.net Cc: Daniel Vetter daniel.vetter@ffwll.ch Cc: Ramalingam C ramalingam.c@intel.com
drivers/gpu/drm/i915/gem/i915_gem_domain.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_domain.c b/drivers/gpu/drm/i915/gem/i915_gem_domain.c index 43004bef55cb..b684a62bf3b0 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_domain.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_domain.c @@ -490,6 +490,9 @@ i915_gem_set_domain_ioctl(struct drm_device *dev, void *data, u32 write_domain = args->write_domain; int err;
if (IS_DGFX(to_i915(dev)))return -ENODEV;/* Only handle setting domains to types used by the CPU. */ if ((write_domain | read_domains) & I915_GEM_GPU_DOMAINS) return -EINVAL;-- 2.26.3