igt/gem_mmap_wc: Test cpu mmap vs wc mmap coherency

Similar to the cpu mmap vs gtt mmap coherency test.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

lib/igt_gt.c

@@ -343,3 +343,57 @@ void igt_set_stop_rings(enum stop_ring_flags flags)
 		      "i915_ring_stop readback mismatch 0x%x vs 0x%x\n",
 		      flags, current);
 }
+
+static unsigned int clflush_size;
+
+int igt_setup_clflush(void)
+{
+	FILE *file;
+	char *line = NULL;
+	size_t size = 0;
+	int first_stanza = 1;
+	int has_clflush = 0;
+
+	if (clflush_size)
+		return 1;
+
+	file = fopen("/proc/cpuinfo", "r");
+	if (file == NULL)
+		return 0;
+
+	while (getline(&line, &size, file) != -1) {
+		if (strncmp(line, "processor", 9) == 0) {
+			if (!first_stanza)
+				break;
+			first_stanza = 0;
+		}
+
+		if (strncmp(line, "flags", 5) == 0) {
+			if (strstr(line, "clflush"))
+				has_clflush = 1;
+		}
+
+		if (strncmp(line, "clflush size", 12) == 0) {
+			char *colon = strchr(line, ':');
+			if (colon)
+				clflush_size = atoi(colon + 1);
+		}
+	}
+	free(line);
+	fclose(file);
+
+	return has_clflush && clflush_size;
+}
+
+void igt_clflush_range(void *addr, int size)
+{
+	char *p, *end;
+
+	end = (char *)addr + size;
+	p = (char *)((uintptr_t)addr & ~((uintptr_t)clflush_size - 1));
+
+	asm volatile("mfence" ::: "memory");
+	for (; p < end; p += clflush_size)
+		asm volatile("clflush %0" : "+m" (*(volatile char *)p));
+	asm volatile("mfence" ::: "memory");
+}

lib/igt_gt.h

@@ -74,4 +74,7 @@ enum stop_ring_flags igt_to_stop_ring_flag(int ring);
 void igt_set_stop_rings(enum stop_ring_flags flags);
 enum stop_ring_flags igt_get_stop_rings(void);
 
+int igt_setup_clflush(void);
+void igt_clflush_range(void *addr, int size);
+
 #endif /* IGT_GT_H */

tests/gem_mmap_gtt.c

@@ -253,56 +253,6 @@ test_write_gtt(int fd)
 	munmap(src, OBJECT_SIZE);
 }
 
-static unsigned int clflush_size;
-static int setup_clflush(void)
-{
-	FILE *file;
-	char *line = NULL;
-	size_t size = 0;
-	int first_stanza = 1;
-	int has_clflush = 0;
-
-	file = fopen("/proc/cpuinfo", "r");
-	if (file == NULL)
-		return 0;
-
-	while (getline(&line, &size, file) != -1) {
-		if (strncmp(line, "processor", 9) == 0) {
-			if (!first_stanza)
-				break;
-			first_stanza = 0;
-		}
-
-		if (strncmp(line, "flags", 5) == 0) {
-			if (strstr(line, "clflush"))
-				has_clflush = 1;
-		}
-
-		if (strncmp(line, "clflush size", 12) == 0) {
-			char *colon = strchr(line, ':');
-			if (colon)
-				clflush_size = atoi(colon + 1);
-		}
-	}
-	free(line);
-	fclose(file);
-
-	return has_clflush && clflush_size;
-}
-
-static void clflush(void *addr, int size)
-{
-	char *p, *end;
-
-	end = (char *)addr + size;
-	p = (char *)((uintptr_t)addr & ~((uintptr_t)clflush_size - 1));
-
-	asm volatile("mfence" ::: "memory");
-	for (; p < end; p += clflush_size)
-		asm volatile("clflush %0" : "+m" (*(volatile char *)p));
-	asm volatile("mfence" ::: "memory");
-}
-
 static void
 test_coherency(int fd)
 {
@@ -310,7 +260,7 @@ test_coherency(int fd)
 	uint32_t *gtt, *cpu;
 	int i;
 
-	igt_require(setup_clflush());
+	igt_require(igt_setup_clflush());
 
 	handle = gem_create(fd, OBJECT_SIZE);
 
@@ -321,7 +271,7 @@ test_coherency(int fd)
 	for (i = 0; i < OBJECT_SIZE / 64; i++) {
 		int x = 16*i + (i%16);
 		gtt[x] = i;
-		clflush(&cpu[x], sizeof(cpu[x]));
+		igt_clflush_range(&cpu[x], sizeof(cpu[x]));
 		igt_assert_eq(cpu[x], i);
 	}
 

tests/gem_mmap_wc.c

@@ -217,6 +217,33 @@ test_write(int fd)
 	munmap(src, OBJECT_SIZE);
 }
 
+static void
+test_coherency(int fd)
+{
+	uint32_t handle;
+	uint32_t *wc, *cpu;
+	int i;
+
+	igt_require(igt_setup_clflush());
+
+	handle = gem_create(fd, OBJECT_SIZE);
+
+	wc = gem_mmap__wc(fd, handle, 0, OBJECT_SIZE, PROT_READ | PROT_WRITE);
+	cpu = gem_mmap__cpu(fd, handle, 0, OBJECT_SIZE, PROT_READ | PROT_WRITE);
+	gem_set_domain(fd, handle, I915_GEM_DOMAIN_GTT, I915_GEM_DOMAIN_GTT);
+
+	for (i = 0; i < OBJECT_SIZE / 64; i++) {
+		int x = 16*i + (i%16);
+		wc[x] = i;
+		igt_clflush_range(&cpu[x], sizeof(cpu[x]));
+		igt_assert_eq(cpu[x], i);
+	}
+
+	munmap(cpu, OBJECT_SIZE);
+	munmap(wc, OBJECT_SIZE);
+	gem_close(fd, handle);
+}
+
 static void
 test_write_gtt(int fd)
 {
@@ -446,6 +473,8 @@ igt_main
 		test_read(fd);
 	igt_subtest("write")
 		test_write(fd);
+	igt_subtest("coherency")
+		test_coherency(fd);
 	igt_subtest("write-gtt")
 		test_write_gtt(fd);
 	igt_subtest("read-write")