[PATCH i-g-t] tests/intel/xe_pm: Test to validate vram-sr through Mods during host s2idle

[Soham Purkait]

    Add test to validate vram-sr through Mods during host s2idle. It checks
whether vram self refresh capability is supported through debugfs node and
then introduce host s2idle to check ModS residency to confirm vram self
refresh capability upon success.

Signed-off-by: Soham Purkait <soham.purkait at intel.com>
---
 tests/intel/xe_pm.c | 99 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 98 insertions(+), 1 deletion(-)

diff --git a/tests/intel/xe_pm.c b/tests/intel/xe_pm.c
index 6eb21d5ec..322b22eb0 100644
--- a/tests/intel/xe_pm.c
+++ b/tests/intel/xe_pm.c
@@ -10,9 +10,10 @@
  * Sub-category: Suspend-resume tests
  * Test category: functionality test
  */
-
+#include <ctype.h>
 #include <limits.h>
 #include <fcntl.h>
+#include <stddef.h>
 #include <string.h>
 
 #include "igt.h"
@@ -413,6 +414,46 @@ child_exec(void *arguments)
 	return NULL;
 }
 
+static char *read_content_line(const char *content, const char *prefix)
+{
+	const char *line_start = content;
+	char line[1024];
+	char *result;
+	size_t len;
+
+	while (*line_start) {
+		const char *line_end = strchr(line_start, '\n');
+		size_t line_len = line_end ? (size_t)(line_end - line_start) : strlen(line_start);
+
+		if (line_len >= sizeof(line))
+			line_len = sizeof(line) - 1;
+
+		memcpy(line, line_start, line_len);
+		line[line_len] = '\0';
+
+		if (strstr(line, prefix)) {
+			char *colon = strchr(line, ':');
+
+			if (colon) {
+				colon++;
+				while (isspace((unsigned char)*colon))
+					colon++;
+
+				result = strdup(colon);
+				len = strlen(result);
+				if (len > 0 && result[len - 1] == '\n')
+					result[len - 1] = '\0';
+
+				return result;
+			}
+		}
+		line_start = line_end ? line_end + 1 : NULL;
+		if (!line_start)
+			break;
+	}
+	return NULL;
+}
+
 /**
  * SUBTEST: %s-basic
  * Description: test CPU/GPU in and out of s/d state from %arg[1]
@@ -777,6 +818,57 @@ static void test_mocs_suspend_resume(device_t device, enum igt_suspend_state s_s
 	}
 }
 
+/**
+ * SUBTEST: vrsr-capability-during-host-s2idle
+ * Functionality: pm - vram-sr
+ * Description: Test to validate vram self refresh through
+ * ModS residency counter during host s2idle
+ */
+
+static void test_vrsr_capability_during_host_s2idle(device_t device)
+{
+	u32 bo, placement;
+	u64 s2idle_start_mods, s2idle_end_mods;
+	int dir, ret;
+	char buf[4096] = {0};
+	char *result;
+	void *map;
+
+	dir = igt_debugfs_dir(device.fd_xe);
+	ret = igt_debugfs_simple_read(dir, "vrsr_capable",
+				      buf, sizeof(buf));
+	igt_assert_f(ret >= 0, "vrsr_capable node is not present in debugfs.\n");
+	igt_assert_f(strstr(buf, "true"), "VRSR capability is not supported.");
+
+	placement = vram_memory(device.fd_xe, 0);
+#define XE_BO_SIZE (350 * 1024 * 1024)
+	bo = xe_bo_create(device.fd_xe, 0, XE_BO_SIZE, placement, 0);
+	map = xe_bo_map(device.fd_xe, bo, XE_BO_SIZE);
+	memset(map, 0, XE_BO_SIZE);
+
+	ret = igt_debugfs_simple_read(dir, "gtidle/dgfx_pkg_residencies", buf, sizeof(buf));
+	igt_assert_f(ret >= 0, "dgfx_pkg_residencies node is not present in debugfs.\n");
+
+#define MODS_PREFIX "ModS"
+	result = read_content_line(buf, MODS_PREFIX);
+	igt_assert(result);
+	s2idle_start_mods = (uint64_t)strtoull(result, NULL, 10);
+	free(result);
+
+	igt_system_suspend_autoresume(SUSPEND_STATE_FREEZE, SUSPEND_TEST_NONE);
+	munmap(map, XE_BO_SIZE);
+	memset(buf, 0, sizeof(buf));
+	ret = igt_debugfs_simple_read(dir, "gtidle/dgfx_pkg_residencies", buf, sizeof(buf));
+
+	result = read_content_line(buf, MODS_PREFIX);
+	igt_assert(result);
+
+	s2idle_end_mods = (uint64_t)strtoull(result, NULL, 10);
+	free(result);
+
+	igt_assert(s2idle_start_mods != s2idle_end_mods);
+}
+
 igt_main
 {
 	device_t device;
@@ -936,6 +1028,11 @@ igt_main
 		test_vram_d3cold_threshold(device, sysfs_fd);
 	}
 
+	igt_describe("Validate VRAM self refresh capability during host s2idle");
+	igt_subtest("vrsr-capability-during-host-s2idle") {
+		test_vrsr_capability_during_host_s2idle(device);
+	}
+
 	igt_fixture {
 		close(sysfs_fd);
 		igt_pm_set_d3cold_allowed(device.pci_slot_name, d3cold_allowed);
-- 
2.34.1