From 81b1b599dfd71c958418dad586fa72c8d30d1065 Mon Sep 17 00:00:00 2001 From: Fei Yang Date: Tue, 6 Jun 2023 12:00:42 +0200 Subject: drm/i915: Allow user to set cache at BO creation To comply with the design that buffer objects shall have immutable cache setting through out their life cycle, {set, get}_caching ioctl's are no longer supported from MTL onward. With that change caching policy can only be set at object creation time. The current code applies a default (platform dependent) cache setting for all objects. However this is not optimal for performance tuning. The patch extends the existing gem_create uAPI to let user set PAT index for the object at creation time. The new extension is platform independent, so UMD's can switch to using this extension for older platforms as well, while {set, get}_caching are still supported on these legacy paltforms for compatibility reason. However, since PAT index was not clearly defined for platforms prior to GEN12 (TGL), so we are limiting this externsion to GEN12+ platforms only. See ext_set_pat() in for the implementation details. The documentation related to the PAT/MOCS tables is currently available for Tiger Lake here: https://www.intel.com/content/www/us/en/docs/graphics-for-linux/developer-reference/1-0/tiger-lake.html The documentation for other platforms is currently being updated. BSpec: 45101 Mesa support has been submitted in this merge request: https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22878 The media driver supprt has bin submitted in this merge request: https://github.com/intel/media-driver/pull/1680 The IGT test related to this change is igt@gem_create@create-ext-set-pat Signed-off-by: Fei Yang Cc: Chris Wilson Cc: Matt Roper Cc: Andi Shyti Reviewed-by: Andi Shyti Acked-by: Jordan Justen Tested-by: Jordan Justen Acked-by: Carl Zhang Tested-by: Lihao Gu Signed-off-by: Andi Shyti Acked-by: Tvrtko Ursulin Acked-by: Slawomir Milczarek Link: https://patchwork.freedesktop.org/patch/msgid/20230606100042.482345-2-andi.shyti@linux.intel.com --- drivers/gpu/drm/i915/gem/i915_gem_create.c | 40 ++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) (limited to 'drivers/gpu/drm/i915/gem/i915_gem_create.c') diff --git a/drivers/gpu/drm/i915/gem/i915_gem_create.c b/drivers/gpu/drm/i915/gem/i915_gem_create.c index bfe1dbda4cb7..d24c0ce8805c 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_create.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_create.c @@ -245,6 +245,7 @@ struct create_ext { unsigned int n_placements; unsigned int placement_mask; unsigned long flags; + unsigned int pat_index; }; static void repr_placements(char *buf, size_t size, @@ -394,11 +395,43 @@ static int ext_set_protected(struct i915_user_extension __user *base, void *data return 0; } +static int ext_set_pat(struct i915_user_extension __user *base, void *data) +{ + struct create_ext *ext_data = data; + struct drm_i915_private *i915 = ext_data->i915; + struct drm_i915_gem_create_ext_set_pat ext; + unsigned int max_pat_index; + + BUILD_BUG_ON(sizeof(struct drm_i915_gem_create_ext_set_pat) != + offsetofend(struct drm_i915_gem_create_ext_set_pat, rsvd)); + + /* Limiting the extension only to Meteor Lake */ + if (!IS_METEORLAKE(i915)) + return -ENODEV; + + if (copy_from_user(&ext, base, sizeof(ext))) + return -EFAULT; + + max_pat_index = INTEL_INFO(i915)->max_pat_index; + + if (ext.pat_index > max_pat_index) { + drm_dbg(&i915->drm, "PAT index is invalid: %u\n", + ext.pat_index); + return -EINVAL; + } + + ext_data->pat_index = ext.pat_index; + + return 0; +} + static const i915_user_extension_fn create_extensions[] = { [I915_GEM_CREATE_EXT_MEMORY_REGIONS] = ext_set_placements, [I915_GEM_CREATE_EXT_PROTECTED_CONTENT] = ext_set_protected, + [I915_GEM_CREATE_EXT_SET_PAT] = ext_set_pat, }; +#define PAT_INDEX_NOT_SET 0xffff /** * i915_gem_create_ext_ioctl - Creates a new mm object and returns a handle to it. * @dev: drm device pointer @@ -418,6 +451,7 @@ i915_gem_create_ext_ioctl(struct drm_device *dev, void *data, if (args->flags & ~I915_GEM_CREATE_EXT_FLAG_NEEDS_CPU_ACCESS) return -EINVAL; + ext_data.pat_index = PAT_INDEX_NOT_SET; ret = i915_user_extensions(u64_to_user_ptr(args->extensions), create_extensions, ARRAY_SIZE(create_extensions), @@ -454,5 +488,11 @@ i915_gem_create_ext_ioctl(struct drm_device *dev, void *data, if (IS_ERR(obj)) return PTR_ERR(obj); + if (ext_data.pat_index != PAT_INDEX_NOT_SET) { + i915_gem_object_set_pat_index(obj, ext_data.pat_index); + /* Mark pat_index is set by UMD */ + obj->pat_set_by_user = true; + } + return i915_gem_publish(obj, file, &args->size, &args->handle); } -- cgit v1.2.3