From 0fbcf57077c47b444e91b9ce8a243e6f7f53693d Mon Sep 17 00:00:00 2001 From: Fei Yang Date: Thu, 18 May 2023 22:11:02 -0700 Subject: drm/i915/mtl: end support for set caching ioctl The design is to keep Buffer Object's caching policy immutable through out its life cycle. This patch ends the support for set caching ioctl from MTL onward. While doing that we also set BO's to be 1-way coherent at creation time because GPU is no longer automatically snooping CPU cache. For userspace components needing to fine tune the caching policy for BO's, a follow up patch will extend the GEM_CREATE uAPI to allow them specify caching mode at BO creation time. Signed-off-by: Fei Yang Reviewed-by: Andi Shyti Reviewed-by: Andrzej Hajda Signed-off-by: Andi Shyti Link: https://patchwork.freedesktop.org/patch/msgid/20230519051103.3404990-2-fei.yang@intel.com --- drivers/gpu/drm/i915/gem/i915_gem_domain.c | 3 +++ drivers/gpu/drm/i915/gem/i915_gem_shmem.c | 9 ++++++++- 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_domain.c b/drivers/gpu/drm/i915/gem/i915_gem_domain.c index 05107a6efe45..dfaaa8b66ac3 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_domain.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_domain.c @@ -350,6 +350,9 @@ int i915_gem_set_caching_ioctl(struct drm_device *dev, void *data, if (IS_DGFX(i915)) return -ENODEV; + if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 70)) + return -EOPNOTSUPP; + switch (args->caching) { case I915_CACHING_NONE: level = I915_CACHE_NONE; diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c index 37d1efcd3ca6..cad4a6017f4b 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_shmem.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_shmem.c @@ -601,7 +601,14 @@ static int shmem_object_init(struct intel_memory_region *mem, obj->write_domain = I915_GEM_DOMAIN_CPU; obj->read_domains = I915_GEM_DOMAIN_CPU; - if (HAS_LLC(i915)) + /* + * MTL doesn't snoop CPU cache by default for GPU access (namely + * 1-way coherency). However some UMD's are currently depending on + * that. Make 1-way coherent the default setting for MTL. A follow + * up patch will extend the GEM_CREATE uAPI to allow UMD's specify + * caching mode at BO creation time + */ + if (HAS_LLC(i915) || (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 70))) /* On some devices, we can have the GPU use the LLC (the CPU * cache) for about a 10% performance improvement * compared to uncached. Graphics requests other than -- cgit v1.2.3