[PATCH v8 2/2] tests/intel/xe_pat: validate PAT table using debugfs

[Xin Wang <x.wang@intel.com>]

Use xe_get_pat_sw_config() to parse the kernel-exposed PAT layout from
debugfs and validate it against IGT's predefined UC/WT/WB/UC_COMP mapping
returned by intel_get_pat_idx_*().

This helps catch drift as new platforms are added, while keeping the
common library path free of debugfs dependencies.

Also use the debugfs-provided reserved flags to determine which PAT
indices should be rejected by the kernel, instead of hard-coding the
reserved range.

V2:
 - Validate the parsed sw config against intel_pat getters

CC: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Xin Wang <x.wang@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
---
 tests/intel/xe_pat.c | 48 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 46 insertions(+), 2 deletions(-)

diff --git a/tests/intel/xe_pat.c b/tests/intel/xe_pat.c
index 2fd3635fd..9b8ea165f 100644
--- a/tests/intel/xe_pat.c
+++ b/tests/intel/xe_pat.c
@@ -77,6 +77,18 @@ static void userptr_coh_none(int fd)
 	xe_vm_destroy(fd, vm);
 }
 
+#define BITS_TO(n)		(n >= sizeof(long) * 8 ? ~0 : (1UL << (n)) - 1)
+#define BITMASK(high, low)	(uint32_t)(BITS_TO(high+1) & ~BITS_TO(low))
+#define FIELD_GET(val, high, low)	(((val) & (BITMASK(high, low))) >> (low))
+#define FIELD_GET_BIT(val, n)		FIELD_GET(val, n, n)
+
+#define XE_NO_PROMOTE(val)	FIELD_GET_BIT(val, 10)
+#define XE_COMP_EN(val)		FIELD_GET_BIT(val, 9)
+#define XE_L3_CLOS(val)		FIELD_GET(val, 7, 6)
+#define XE_L3_POLICY(val)	FIELD_GET(val, 5, 4)
+#define XE_L4_POLICY(val)	FIELD_GET(val, 3, 2)
+#define XE_COH_MODE(val)	FIELD_GET(val, 1, 0)
+
 /**
  * SUBTEST: pat-index-all
  * Test category: functionality test
@@ -86,6 +98,7 @@ static void pat_index_all(int fd)
 {
 	uint16_t dev_id = intel_get_drm_devid(fd);
 	size_t size = xe_get_default_alignment(fd);
+	struct intel_pat_cache pat_sw_config = {};
 	uint32_t vm, bo;
 	uint8_t pat_index;
 
@@ -114,10 +127,41 @@ static void pat_index_all(int fd)
 
 	igt_assert(intel_get_max_pat_index(fd));
 
+	if (intel_graphics_ver(dev_id) >= IP_VER(20, 0)) {
+		/* Get the Xe PAT software configuration from the debugfs.*/
+		int32_t parsed = xe_get_pat_sw_config(fd, &pat_sw_config);
+		igt_require_f(parsed > 0,
+			      "Couldn't get Xe PAT software configuration\n");
+		for (int i = 0; i < parsed; i++) {
+			uint32_t pat = pat_sw_config.entries[i].pat;
+			igt_debug("PAT[%2d] = [ %u, %u, %u, %u, %u, %u]  (%#8x)%s\n", i,
+				  XE_NO_PROMOTE(pat),
+				  XE_COMP_EN(pat),
+				  XE_L3_CLOS(pat),
+				  XE_L3_POLICY(pat),
+				  XE_L4_POLICY(pat),
+				  XE_COH_MODE(pat),
+				  pat,
+				  pat_sw_config.entries[i].rsvd ? " *" : "");
+		}
+
+		/* Validate the parsed sw config against intel_pat getters */
+		igt_assert(pat_sw_config.max_index == intel_get_max_pat_index(fd));
+		igt_assert(pat_sw_config.uc == intel_get_pat_idx_uc(fd));
+		igt_assert(pat_sw_config.wb == intel_get_pat_idx_wb(fd));
+		if (intel_graphics_ver(dev_id) != IP_VER(35, 11)) {
+			igt_assert(pat_sw_config.wt == intel_get_pat_idx_wt(fd));
+			igt_assert(pat_sw_config.uc_comp == intel_get_pat_idx_uc_comp(fd));
+		}
+	}
+
 	for (pat_index = 0; pat_index <= intel_get_max_pat_index(fd);
 	     pat_index++) {
-		if (intel_get_device_info(dev_id)->graphics_ver >= 20 &&
-		    pat_index >= 16 && pat_index <= 19) { /* hw reserved */
+
+		bool hw_reserved = intel_graphics_ver(dev_id) >= IP_VER(20, 0) ?
+				   pat_sw_config.entries[pat_index].rsvd : false;
+
+		if (hw_reserved) {
 			igt_assert_eq(__xe_vm_bind(fd, vm, 0, bo, 0, 0x40000,
 						   size, DRM_XE_VM_BIND_OP_MAP, 0, NULL, 0, 0,
 						   pat_index, 0),
-- 
2.43.0