[i-g-t V3 4/4] tests/xe/mmap: add tests for pci mem barrier

[Tejas Upadhyay]

We want to make sure that mmap do direct mapping of physical
page at doorbell space and whole page is accessible in order
to use pci memory barrier effect effectively.

Following subtests are added,
./build/tests/xe_mmap --r pci-membarrier
./build/tests/xe_mmap --r pci-membarrier-bad-pagesize
./build/tests/xe_mmap --r pci-membarrier-bad-object

V2(MAuld)
 - use do_ioctl and replace igt_subtest_f with igt_subtest
 - Remove unused define

Reviewed-by: Matthew Auld <matthew.auld at intel.com>
Signed-off-by: Tejas Upadhyay <tejas.upadhyay at intel.com>
---
 tests/intel/xe_mmap.c | 95 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)

diff --git a/tests/intel/xe_mmap.c b/tests/intel/xe_mmap.c
index fc5d73d59..2e5cab622 100644
--- a/tests/intel/xe_mmap.c
+++ b/tests/intel/xe_mmap.c
@@ -64,6 +64,73 @@ test_mmap(int fd, uint32_t placement, uint32_t flags)
 	gem_close(fd, bo);
 }
 
+#define PAGE_SIZE 4096
+
+/**
+ * SUBTEST: pci-membarrier
+ * Description: create pci memory barrier with write on defined mmap offset.
+ * Test category: functionality test
+ *
+ */
+static void test_pci_membarrier(int xe)
+{
+	uint64_t flags = MAP_SHARED;
+	unsigned int prot = PROT_WRITE;
+	uint32_t *ptr;
+	uint64_t size = PAGE_SIZE;
+	struct timespec tv;
+	struct drm_xe_gem_mmap_offset mmo = {
+		.handle = 0,
+		.flags = DRM_XE_MMAP_OFFSET_FLAG_PCI_BARRIER,
+	};
+
+	do_ioctl(xe, DRM_IOCTL_XE_GEM_MMAP_OFFSET, &mmo);
+	ptr = mmap(NULL, size, prot, flags, xe, mmo.offset);
+	igt_assert(ptr != MAP_FAILED);
+
+	/* Check whole page for any errors, also check as
+	 * we should not read written values back
+	 */
+	for (int i = 0; i < size / sizeof(*ptr); i++) {
+		/* It is expected unconfigured doorbell space
+		 * will return read value 0xdeadbeef
+		 */
+		igt_assert_eq_u32(READ_ONCE(ptr[i]), 0xdeadbeef);
+
+		igt_gettime(&tv);
+		ptr[i] = i;
+		if (READ_ONCE(ptr[i]) == i) {
+			while (READ_ONCE(ptr[i]) == i)
+				;
+			igt_info("fd:%d value retained for %"PRId64"ns pos:%d\n",
+				 xe, igt_nsec_elapsed(&tv), i);
+		}
+		igt_assert_neq(READ_ONCE(ptr[i]), i);
+	}
+
+	munmap(ptr, size);
+}
+
+/**
+ * SUBTEST: pci-membarrier-bad-pagesize
+ * Description: Test mmap offset with bad pagesize for pci membarrier.
+ * Test category: negative test
+ *
+ */
+static void test_bad_pagesize_for_pcimem(int fd)
+{
+	uint32_t *map;
+	uint64_t page_size = PAGE_SIZE * 2;
+	struct drm_xe_gem_mmap_offset mmo = {
+		.handle = 0,
+		.flags = DRM_XE_MMAP_OFFSET_FLAG_PCI_BARRIER,
+	};
+
+	do_ioctl(fd, DRM_IOCTL_XE_GEM_MMAP_OFFSET, &mmo);
+	map = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, fd, mmo.offset);
+	igt_assert(map == MAP_FAILED);
+}
+
 /**
  * SUBTEST: bad-flags
  * Description: Test mmap offset with bad flags.
@@ -126,6 +193,25 @@ static void test_bad_object(int fd)
 	do_ioctl_err(fd, DRM_IOCTL_XE_GEM_MMAP_OFFSET, &mmo, ENOENT);
 }
 
+/**
+ * SUBTEST: pci-membarrier-bad-object
+ * Description: Test mmap offset with bad object for pci mem barrier.
+ * Test category: negative test
+ *
+ */
+static void test_bad_object_for_pcimem(int fd)
+{
+	uint64_t size = xe_get_default_alignment(fd);
+	struct drm_xe_gem_mmap_offset mmo = {
+		.handle = xe_bo_create(fd, 0, size,
+				       vram_if_possible(fd, 0),
+				       DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM),
+		.flags = DRM_XE_MMAP_OFFSET_FLAG_PCI_BARRIER,
+	};
+
+	do_ioctl_err(fd, DRM_IOCTL_XE_GEM_MMAP_OFFSET, &mmo, EINVAL);
+}
+
 static jmp_buf jmp;
 
 __noreturn static void sigtrap(int sig)
@@ -273,6 +359,12 @@ igt_main
 		test_mmap(fd, vram_memory(fd, 0) | system_memory(fd),
 			  DRM_XE_GEM_CREATE_FLAG_NEEDS_VISIBLE_VRAM);
 
+	igt_subtest("pci-membarrier")
+		test_pci_membarrier(fd);
+
+	igt_subtest("pci-membarrier-bad-pagesize")
+		test_bad_pagesize_for_pcimem(fd);
+
 	igt_subtest("bad-flags")
 		test_bad_flags(fd);
 
@@ -282,6 +374,9 @@ igt_main
 	igt_subtest("bad-object")
 		test_bad_object(fd);
 
+	igt_subtest("pci-membarrier-bad-object")
+		test_bad_object_for_pcimem(fd);
+
 	igt_subtest("small-bar") {
 		igt_require(xe_visible_vram_size(fd, 0));
 		igt_require(xe_visible_vram_size(fd, 0) < xe_vram_size(fd, 0));
-- 
2.34.1