---
drivers/gpu/drm/i915/gem/i915_gem_create.c | 40 +++++++++++++++++++++
drivers/gpu/drm/i915/gem/i915_gem_object.c | 6 ++++
include/uapi/drm/i915_drm.h | 41 ++++++++++++++++++++++
3 files changed, 87 insertions(+)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_create.c b/drivers/gpu/drm/i915/gem/i915_gem_create.c
index bfe1dbda4cb75..d24c0ce8805c7 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);
}
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c
index 46a19b099ec88..97ac6fb37958f 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c
@@ -208,6 +208,12 @@ bool i915_gem_object_can_bypass_llc(struct drm_i915_gem_object *obj)
if (!(obj->flags & I915_BO_ALLOC_USER))
return false;
+ /*
+ * Always flush cache for UMD objects at creation time.
+ */
+ if (obj->pat_set_by_user)
+ return true;
+
/*
* EHL and JSL add the 'Bypass LLC' MOCS entry, which should make it
* possible for userspace to bypass the GTT caching bits set by the
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index a1848e8060590..7000e5910a1d7 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -3680,9 +3680,13 @@ struct drm_i915_gem_create_ext {
*
* For I915_GEM_CREATE_EXT_PROTECTED_CONTENT usage see
* struct drm_i915_gem_create_ext_protected_content.
+ *
+ * For I915_GEM_CREATE_EXT_SET_PAT usage see
+ * struct drm_i915_gem_create_ext_set_pat.
*/
#define I915_GEM_CREATE_EXT_MEMORY_REGIONS 0
#define I915_GEM_CREATE_EXT_PROTECTED_CONTENT 1
+#define I915_GEM_CREATE_EXT_SET_PAT 2
__u64 extensions;
};
@@ -3797,6 +3801,43 @@ struct drm_i915_gem_create_ext_protected_content {
__u32 flags;
};
+/**
+ * struct drm_i915_gem_create_ext_set_pat - The
+ * I915_GEM_CREATE_EXT_SET_PAT extension.
+ *
+ * If this extension is provided, the specified caching policy (PAT index) is
+ * applied to the buffer object.
+ *
+ * Below is an example on how to create an object with specific caching policy:
+ *
+ * .. code-block:: C
+ *
+ * struct drm_i915_gem_create_ext_set_pat set_pat_ext = {
+ * .base = { .name = I915_GEM_CREATE_EXT_SET_PAT },
+ * .pat_index = 0,
+ * };
+ * struct drm_i915_gem_create_ext create_ext = {
+ * .size = PAGE_SIZE,
+ * .extensions = (uintptr_t)&set_pat_ext,
+ * };
+ *
+ * int err = ioctl(fd, DRM_IOCTL_I915_GEM_CREATE_EXT, &create_ext);
+ * if (err) ...
+ */
+struct drm_i915_gem_create_ext_set_pat {
+ /** @base: Extension link. See struct i915_user_extension. */
+ struct i915_user_extension base;
+ /**
+ * @pat_index: PAT index to be set
+ * PAT index is a bit field in Page Table Entry to control caching
+ * behaviors for GPU accesses. The definition of PAT index is
+ * platform dependent and can be found in hardware specifications,
+ */
+ __u32 pat_index;
+ /** @rsvd: reserved for future use */
+ __u32 rsvd;
+};
+
/* ID of the protected content session managed by i915 when PXP is active */
#define I915_PROTECTED_CONTENT_DEFAULT_SESSION 0xf
