[PATCH i-g-t] tests/intel/xe_evict_ccs: This patch adjust object size as per VRAM

[Sobin Thomas]

Some BIOS configurations do not support or enable resizable BAR,
resulting in a maximum BAR size of 256MB. This patch adjusts the
maximum object size used in test conditions based on the available
VRAM.

v2: Adjusted the subject name

v3: Inco-operated review comments [kamil]

v4: Fixed typo.

v5: Fixed review comment for igt warnings and commit subject. [kamil]
    Fixed the condition for user provided max size value. [kamil]

Signed-off-by: Sobin Thomas <sobin.thomas at intel.com>
---
 tests/intel/xe_evict_ccs.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/tests/intel/xe_evict_ccs.c b/tests/intel/xe_evict_ccs.c
index 281d27015..16abba4ec 100644
--- a/tests/intel/xe_evict_ccs.c
+++ b/tests/intel/xe_evict_ccs.c
@@ -39,12 +39,14 @@ static struct param {
 	int vram_percent;
 	int min_size_kb;
 	int max_size_kb;
+	bool user_set_max_size;
 	bool verify;
 } params = {
 	.num_objs = 0,
 	.vram_percent = OVERCOMMIT_VRAM_PERCENT,
 	.min_size_kb = MIN_OBJ_KB,
 	.max_size_kb = MAX_OBJ_KB,
+	.user_set_max_size = false,
 };
 
 struct object {
@@ -343,6 +345,34 @@ static void set_config(int fd, uint32_t flags, const struct param *param,
 	igt_debug("nproc: %d, mem per proc: %dMB\n", nproc, config->mb_per_proc);
 }
 
+static void adjust_params_for_vram_size(uint64_t vram_size)
+{
+	uint64_t vram_mb = vram_size / (1024 * 1024);
+	int recommended_max_size_kb = 0;
+	int max_object_mb = vram_mb / MIN_OBJ_KB;
+
+	/* max_object_mb clamped between 2MB and 256MB */
+	max_object_mb = max_t(int, 2, min_t(int, max_object_mb, 256));
+	recommended_max_size_kb = max_object_mb * 1024;
+
+	igt_info("VRAM (%"PRIu64"MB): Calculated %d%% usage, %dMB max objects\n",
+		 vram_mb, params.vram_percent, max_object_mb);
+
+	if (params.user_set_max_size &&
+		params.max_size_kb > recommended_max_size_kb) {
+		igt_warn("User specified size (%dMB) may not be optimal for %"PRIu64"MB VRAM\n"
+				"(recommended size: %dMB)\n",
+				params.max_size_kb / 1024, vram_mb,
+				recommended_max_size_kb / 1024);
+
+	} else {
+		params.max_size_kb = recommended_max_size_kb;
+	}
+
+	igt_info("Final settings: %d%% VRAM, %dMB max object\n",
+		 params.vram_percent, params.max_size_kb / 1024);
+}
+
 static void evict_ccs(int fd, uint32_t flags, const struct param *param)
 {
 	struct config config;
@@ -440,6 +470,7 @@ static int opt_handler(int opt, int opt_index, void *data)
 		break;
 	case 'S':
 		params.max_size_kb = atoi(optarg);
+		params.user_set_max_size = true;
 		igt_debug("Max size kb: %d\n", params.max_size_kb);
 		break;
 	case 'V':
@@ -500,6 +531,7 @@ igt_main_args("bdDn:p:s:S:V", NULL, help_str, opt_handler, NULL)
 		igt_require(xe_has_vram(fd));
 		vram_size = xe_visible_vram_size(fd, 0);
 		igt_assert(vram_size);
+		adjust_params_for_vram_size(vram_size);
 		has_flatccs = HAS_FLATCCS(intel_get_drm_devid(fd));
 	}
 
-- 
2.34.1