[igt-dev] [PATCH i-g-t v6 2/4] lib/igt_sysfs: Handling gt related sysfs uapi changes

[Himal Prasad Ghimiray]

Patch https://patchwork.freedesktop.org/series/118927/
is moving gt sysfs parent under tile folder.

With the above patch path for sysfs changes:
from: /sys/class/drm/cardX/device/gtN/
to : /sys/class/drm/cardX/device/tileN/gtN

Adding xe_gt_sysfs_path function to access new path.

v2:
- Calculate number of tiles once within iterator. (Rahul)

v3:
- Drop usage of local variable for tilecount.
- Change order of tile and gt. (Ashutosh)

v4:
- Drop xe_for_each_gt_under_each_tile macro
  add xe_gt_sysfs_path to return path. (Ashutosh)
- Support older dir path along with new. (kamil)

v5:
- Initialize the variable and use for loop
instead of while.

Cc: Kamil Konieczny <kamil.konieczny at linux.intel.com>
Cc: Aravind Iddamsetty <aravind.iddamsetty at intel.com>
Cc: Upadhyay <tejas.upadhyay at intel.com>
Cc: Janga Rahul Kumar <janga.rahul.kumar at intel.com>
Cc: Francois Dugast <francois.dugast at intel.com>
Cc: Ashutosh Dixit <ashutosh.dixit at intel.com>
Cc: Matt Roper <matthew.d.roper at intel.com>
Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
---
 lib/igt_sysfs.c | 40 ++++++++++++++++++++++++++++++++++++++++
 lib/igt_sysfs.h |  1 +
 2 files changed, 41 insertions(+)

diff --git a/lib/igt_sysfs.c b/lib/igt_sysfs.c
index 2ea9eb1b9..32d78cfb6 100644
--- a/lib/igt_sysfs.c
+++ b/lib/igt_sysfs.c
@@ -46,6 +46,7 @@
 #include "igt_device.h"
 #include "igt_io.h"
 
+#define XE_MAX_GT_SYSFS_PATH 3
 /**
  * SECTION:igt_sysfs
  * @short_description: Support code for sysfs features
@@ -933,3 +934,42 @@ void igt_sysfs_engines(int xe, int engines, const char **property,
 		close(engine_fd);
 	}
 }
+
+/**
+ * xe_gt_sysfs_path::
+ * @sysfs: fd of sysfs
+ * @gt_id: gt id
+ *
+ * This function returns the path for gtX directory
+ */
+char *xe_gt_sysfs_path(int sysfs, int gt_id)
+{
+	char path[XE_MAX_GT_SYSFS_PATH][32];
+	struct stat gtpathstat;
+	char *gt_path;
+	int i;
+
+	/* Path for multitile platforms with single gt on each tile
+	 * Tile id will be same as gt id.
+	 */
+	snprintf(path[0], sizeof(path[0]), "device/tile%d/gt%d/", gt_id, gt_id);
+
+	/* Path for single tile platforms with multiple gt's
+	 * all gt's will be under tile0 eg: MTL.
+	 */
+	snprintf(path[1], sizeof(path[1]), "device/tile0/gt%d/", gt_id);
+
+	/* Path not under tile.
+	 * To support older dir structure.
+	 */
+	snprintf(path[2], sizeof(path[2]), "device/gt%d/", gt_id);
+
+	for (i = 0; i < XE_MAX_GT_SYSFS_PATH; i++) {
+		if (!fstatat(sysfs, path[i], &gtpathstat, 0) && S_ISDIR(gtpathstat.st_mode)) {
+			gt_path = malloc(sizeof(path[i]));
+			strcpy(gt_path, path[i]);
+			return gt_path;
+		}
+	}
+	igt_assert_f(false, "No gt%d dir found in sysfs", gt_id);
+}
diff --git a/lib/igt_sysfs.h b/lib/igt_sysfs.h
index c31765542..a937ee7b5 100644
--- a/lib/igt_sysfs.h
+++ b/lib/igt_sysfs.h
@@ -153,6 +153,7 @@ typedef struct igt_sysfs_rw_attr {
 } igt_sysfs_rw_attr_t;
 
 void igt_sysfs_rw_attr_verify(igt_sysfs_rw_attr_t *rw);
+char *xe_gt_sysfs_path(int sysfs, int gt_id);
 
 void igt_sysfs_engines(int xe, int engines, const char **property,
 		       void (*test)(int, int, const char **));
-- 
2.25.1