[igt-dev] [PATCH i-g-t 1/2] lib/igt_sysfs: Add helpers to iterate over gts

[Ashutosh Dixit]

From: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>

Provide iterators to:
- construct the subdirectory string for a gt
- obtain fd for the subdirectory of the interface

Cc: Andi Shyti <andi.shyti at intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Cc: Sujaritha Sundaresan <sujaritha.sundaresan at intel.com>
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
---
 lib/igt_sysfs.c | 137 ++++++++++++++++++++++++++++++++++++++++++++++++
 lib/igt_sysfs.h |  67 +++++++++++++++++++++++
 2 files changed, 204 insertions(+)

diff --git a/lib/igt_sysfs.c b/lib/igt_sysfs.c
index f8ef23e2c8e2..1ba26c0b3fc2 100644
--- a/lib/igt_sysfs.c
+++ b/lib/igt_sysfs.c
@@ -44,6 +44,87 @@
 #include "igt_device.h"
 #include "igt_io.h"
 
+enum {
+	GT,
+	RPS,
+
+	SYSFS_NUM_TYPES,
+};
+
+static const char *i915_attr_name[SYSFS_NUM_TYPES][SYSFS_NUM_ATTR] = {
+	{
+		"gt_act_freq_mhz",
+		"gt_cur_freq_mhz",
+		"gt_min_freq_mhz",
+		"gt_max_freq_mhz",
+		"gt_RP0_freq_mhz",
+		"gt_RP1_freq_mhz",
+		"gt_RPn_freq_mhz",
+		"gt_idle_freq_mhz",
+		"gt_boost_freq_mhz",
+		"power/rc6_enable",
+		"power/rc6_residency_ms",
+		"power/rc6p_residency_ms",
+		"power/rc6pp_residency_ms",
+		"power/media_rc6_residency_ms",
+	},
+	{
+		"rps_act_freq_mhz",
+		"rps_cur_freq_mhz",
+		"rps_min_freq_mhz",
+		"rps_max_freq_mhz",
+		"rps_RP0_freq_mhz",
+		"rps_RP1_freq_mhz",
+		"rps_RPn_freq_mhz",
+		"rps_idle_freq_mhz",
+		"rps_boost_freq_mhz",
+		"rc6_enable",
+		"rc6_residency_ms",
+		"rc6p_residency_ms",
+		"rc6pp_residency_ms",
+		"media_rc6_residency_ms",
+	},
+};
+
+/**
+ * igt_sysfs_has_attr:
+ * @dir: sysfs directory fd
+ * @attr: attr inside sysfs dir that needs to be checked for existence
+ *
+ * This checks if specified attr exists in device sysfs directory.
+ *
+ * Returns:
+ * true if attr exists in sysfs, false otherwise.
+ */
+bool igt_sysfs_has_attr(int dir, const char *attr)
+{
+	return !faccessat(dir, attr, F_OK, 0);
+}
+
+const char *igt_sysfs_dir_id_to_name(int dir, enum i915_attr_id id)
+{
+	igt_assert(id < SYSFS_NUM_ATTR);
+
+	return igt_sysfs_has_attr(dir, i915_attr_name[GT][id]) ?
+		i915_attr_name[GT][id] :
+		i915_attr_name[RPS][id];
+}
+
+const char *igt_sysfs_path_id_to_name(const char *path, enum i915_attr_id id)
+{
+	int dir;
+	const char *name;
+
+	dir = open(path, O_RDONLY);
+	if (dir < 0)
+		return NULL;
+
+	name = igt_sysfs_dir_id_to_name(dir, id);
+	close(dir);
+
+	return name;
+}
+
 /**
  * SECTION:igt_sysfs
  * @short_description: Support code for sysfs features
@@ -104,6 +185,62 @@ int igt_sysfs_open(int device)
 	return open(path, O_RDONLY);
 }
 
+/**
+ * igt_sysfs_gt_path:
+ * @device: fd of the device
+ * @gt: gt number
+ * @path: buffer to fill with the sysfs gt path to the device
+ * @pathlen: length of @path buffer
+ *
+ * This finds the sysfs directory corresponding to @device and @gt. If the gt
+ * specific directory is not available and gt is 0, path is filled with sysfs
+ * base directory.
+ *
+ * Returns:
+ * The directory path, or NULL on failure.
+ */
+char *igt_sysfs_gt_path(int device, int gt, char *path, int pathlen)
+{
+	struct stat st;
+
+	if (device < 0)
+		return NULL;
+
+	if (igt_debug_on(fstat(device, &st)) || igt_debug_on(!S_ISCHR(st.st_mode)))
+		return NULL;
+
+	snprintf(path, pathlen, "/sys/dev/char/%d:%d/gt/gt%d",
+		 major(st.st_rdev), minor(st.st_rdev), gt);
+
+	if (!igt_debug_on(access(path, F_OK)))
+		return path;
+	else if (!igt_debug_on(gt != 0))
+		return igt_sysfs_path(device, path, pathlen);
+
+	return NULL;
+}
+
+/**
+ * igt_sysfs_gt_open:
+ * @device: fd of the device
+ * @gt: gt number
+ *
+ * This opens the sysfs gt directory corresponding to device and gt for use
+ * with igt_sysfs_set() and igt_sysfs_get().
+ *
+ * Returns:
+ * The directory fd, or -1 on failure.
+ */
+int igt_sysfs_gt_open(int device, int gt)
+{
+	char path[96];
+
+	if (igt_debug_on(!igt_sysfs_gt_path(device, gt, path, sizeof(path))))
+		return -1;
+
+	return open(path, O_RDONLY);
+}
+
 /**
  * igt_sysfs_write:
  * @dir: directory for the device from igt_sysfs_open()
diff --git a/lib/igt_sysfs.h b/lib/igt_sysfs.h
index 56741a0a37e3..8e39b8fa9890 100644
--- a/lib/igt_sysfs.h
+++ b/lib/igt_sysfs.h
@@ -28,8 +28,75 @@
 #include <stdbool.h>
 #include <stdarg.h>
 
+#define for_each_sysfs_gt_path(i915__, path__, pathlen__) \
+	for (int gt__ = 0; \
+	     igt_sysfs_gt_path(i915__, gt__, path__, pathlen__) != NULL; \
+	     gt__++)
+
+#define for_each_sysfs_gt_dirfd(i915__, dirfd__, gt__) \
+	for (gt__ = 0; \
+	     (dirfd__ = igt_sysfs_gt_open(i915__, gt__)) != -1; \
+	     close(dirfd__), gt__++)
+
+#define igt_sysfs_rps_write(dir, id, data, len) \
+	igt_sysfs_write(dir, igt_sysfs_dir_id_to_name(dir, id), data, len)
+
+#define igt_sysfs_rps_read(dir, id, data, len) \
+	igt_sysfs_read(dir, igt_sysfs_dir_id_to_name(dir, id), data, len)
+
+#define igt_sysfs_rps_set(dir, id, value) \
+	igt_sysfs_set(dir, igt_sysfs_dir_id_to_name(dir, id), value)
+
+#define igt_sysfs_rps_get(dir, id) \
+	igt_sysfs_get(dir, igt_sysfs_dir_id_to_name(dir, id))
+
+#define igt_sysfs_rps_scanf(dir, id, fmt, ...) \
+	igt_sysfs_scanf(dir, igt_sysfs_dir_id_to_name(dir, id), fmt, ##__VA_ARGS__)
+
+#define igt_sysfs_rps_vprintf(dir, id, fmt, ap) \
+	igt_sysfs_vprintf(dir, igt_sysfs_dir_id_to_name(id), fmt, ap)
+
+#define igt_sysfs_rps_printf(dir, id, fmt, ...) \
+	igt_sysfs_printf(dir, igt_sysfs_dir_id_to_name(dir, id), fmt, ##__VA_ARGS__)
+
+#define igt_sysfs_rps_get_u32(dir, id) \
+	igt_sysfs_get_u32(dir, igt_sysfs_dir_id_to_name(dir, id))
+
+#define igt_sysfs_rps_set_u32(dir, id, value) \
+	igt_sysfs_set_u32(dir, igt_sysfs_dir_id_to_name(dir, id), value)
+
+#define igt_sysfs_rps_get_boolean(dir, id) \
+	igt_sysfs_get_boolean(dir, igt_sysfs_dir_id_to_name(dir, id))
+
+#define igt_sysfs_rps_set_boolean(dir, id, value) \
+	igt_sysfs_set_boolean(dir, igt_sysfs_dir_id_to_name(dir, id), value)
+
+enum i915_attr_id {
+	RPS_ACT_FREQ_MHZ,
+	RPS_CUR_FREQ_MHZ,
+	RPS_MIN_FREQ_MHZ,
+	RPS_MAX_FREQ_MHZ,
+	RPS_RP0_FREQ_MHZ,
+	RPS_RP1_FREQ_MHZ,
+	RPS_RPn_FREQ_MHZ,
+	RPS_IDLE_FREQ_MHZ,
+	RPS_BOOST_FREQ_MHZ,
+	RC6_ENABLE,
+	RC6_RESIDENCY_MS,
+	RC6P_RESIDENCY_MS,
+	RC6PP_RESIDENCY_MS,
+	MEDIA_RC6_RESIDENCY_MS,
+
+	SYSFS_NUM_ATTR,
+};
+
 char *igt_sysfs_path(int device, char *path, int pathlen);
 int igt_sysfs_open(int device);
+char *igt_sysfs_gt_path(int device, int gt, char *path, int pathlen);
+int igt_sysfs_gt_open(int device, int gt);
+bool igt_sysfs_has_attr(int dir, const char *attr);
+const char *igt_sysfs_dir_id_to_name(int dir, enum i915_attr_id id);
+const char *igt_sysfs_path_id_to_name(const char *path, enum i915_attr_id id);
 
 int igt_sysfs_read(int dir, const char *attr, void *data, int len);
 int igt_sysfs_write(int dir, const char *attr, const void *data, int len);
-- 
2.34.1