[igt-dev] [PATCH v5 1/1] test/gem_create: exercise gem_create_ext_set_pat

[fei.yang@intel.com]

From: Fei Yang <fei.yang@intel.com>

Gem_create uAPI has been extended with capability of setting PAT index.
Add a test case to exercise it.

PAT index is a page attribute that gets programmed into Page Table
Entry (PTE) for caching policy control. Please refer to kernel patch
for implementation details.

https://patchwork.freedesktop.org/series/116870/

Signed-off-by: Fei Yang <fei.yang@intel.com>
---
 lib/i915/i915_drm_local.h | 34 +++++++++++++++++++++++
 tests/i915/gem_create.c   | 58 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 92 insertions(+)

diff --git a/lib/i915/i915_drm_local.h b/lib/i915/i915_drm_local.h
index bb2ebef3..0f47578c 100644
--- a/lib/i915/i915_drm_local.h
+++ b/lib/i915/i915_drm_local.h
@@ -41,6 +41,40 @@ extern "C" {
 #define __I915_PMU_RC6_RESIDENCY(gt)		___I915_PMU_OTHER(gt, 3)
 #define __I915_PMU_SOFTWARE_GT_AWAKE_TIME(gt)	___I915_PMU_OTHER(gt, 4)
 
+#define I915_GEM_CREATE_EXT_SET_PAT 2
+
+/**
+ * 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 */
+	__u32 pat_index;
+	/** @rsvd: reserved for future use */
+	__u32 rsvd;
+};
+
 #if defined(__cplusplus)
 }
 #endif
diff --git a/tests/i915/gem_create.c b/tests/i915/gem_create.c
index fc991894..2e0c0ab9 100644
--- a/tests/i915/gem_create.c
+++ b/tests/i915/gem_create.c
@@ -587,6 +587,60 @@ static void create_ext_placement_each(int fd)
 	free(regions);
 }
 
+/**
+  * TEST: GEM create uAPI
+  * Category: Infrastructure
+  * Description: Tests the DRM_IOCTL_I915_GEM_CREATE_EXT ioctl.
+  * Feature: core
+  * Functionality: Create GEM object with specific PAT index
+  * Run type: BAT
+  * Sub-category: i915
+  * Test category: GEM_Legacy
+  *
+  * SUBTEST: create-ext-set-pat
+  */
+static void create_ext_set_pat(int fd)
+{
+	struct drm_i915_gem_create_ext_set_pat setparam_pat = {
+		.base = { .name = I915_GEM_CREATE_EXT_SET_PAT },
+		.pat_index = 0,
+	};
+	struct drm_i915_gem_create_ext_set_pat setparam_inv_pat = {
+		.base = { .name = I915_GEM_CREATE_EXT_SET_PAT },
+		.pat_index = 65,
+	};
+	struct drm_i915_gem_caching arg;
+	uint64_t size;
+	uint32_t handle;
+	int ret;
+
+	size = PAGE_SIZE;
+
+	ret = __gem_create_ext(fd, &size, 0, &handle, &setparam_pat.base);
+
+	/*
+	 * With a valid PAT index specified, returning -EINVAL here
+	 * indicates set_pat extension is not supported
+	 */
+	if (ret == -EINVAL)
+		igt_skip("I915_GEM_CREATE_EXT_SET_PAT is not supported\n");
+	igt_assert(ret == 0);
+
+	/* {set|get}_caching ioctl should fail for objects created with set_pat */
+	igt_assert_eq(__gem_set_caching(fd, handle, 1), -EOPNOTSUPP);
+
+	memset(&arg, 0, sizeof(arg));
+	arg.handle = handle;
+	igt_assert(ioctl(fd, DRM_IOCTL_I915_GEM_GET_CACHING, &arg) < 0 &&
+		   errno == EOPNOTSUPP);
+
+	/* gem_create should fail with -EINVAL if invalid pat index specified */
+	igt_assert_eq(__gem_create_ext(fd, &size, 0, &handle, &setparam_inv_pat.base),
+		      -EINVAL);
+
+	gem_close(fd, handle);
+}
+
 static bool supports_needs_cpu_access(int fd)
 {
 	struct drm_i915_gem_memory_class_instance regions[] = {
@@ -947,6 +1001,10 @@ igt_main
 	igt_subtest("create-ext-placement-all")
 		create_ext_placement_all(fd);
 
+	igt_describe("Validate basic creation of objects with PAT cache setting.");
+	igt_subtest("create-ext-set-pat")
+		create_ext_set_pat(fd);
+
 	igt_describe("Verify the basic functionally and expected ABI contract around I915_GEM_CREATE_EXT_FLAG_NEEDS_CPU_ACCESS");
 	igt_subtest("create-ext-cpu-access-sanity-check") {
 		igt_require(supports_needs_cpu_access(fd));
-- 
2.25.1