[PATCH v2 i-g-t 3/5] lib/xe/xe_sriov_debugfs: Add function to read provisioned ranges

[Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>]

Implement xe_sriov_pf_debugfs_read_provisioned_ranges() to read and
parse VFs provisioned ranges from the debug filesystem. Introduce
xe_sriov_debugfs_provisioned_attr_name() to get the debugfs attribute
name for a given shared resource type.

v2: Correct function description (Adam)

Signed-off-by: Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>
Reviewed-by: Adam Miszczak <adam.miszczak@linux.intel.com>
Cc: Adam Miszczak <adam.miszczak@linux.intel.com>
Cc: Jakub Kolakowski <jakub1.kolakowski@intel.com>
Cc: Marcin Bernatowicz <marcin.bernatowicz@linux.intel.com>
Cc: Michał Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Cc: Narasimha C V <narasimha.c.v@intel.com>
Cc: Piotr Piórkowski <piotr.piorkowski@intel.com>
Cc: Satyanarayana K V P <satyanarayana.k.v.p@intel.com>
Cc: Tomasz Lis <tomasz.lis@intel.com>
---
 lib/xe/xe_sriov_debugfs.c | 139 +++++++++++++++++++++++++++++++++++++-
 lib/xe/xe_sriov_debugfs.h |   8 +++
 2 files changed, 146 insertions(+), 1 deletion(-)

diff --git a/lib/xe/xe_sriov_debugfs.c b/lib/xe/xe_sriov_debugfs.c
index dc6ef9da3..c87f91492 100644
--- a/lib/xe/xe_sriov_debugfs.c
+++ b/lib/xe/xe_sriov_debugfs.c
@@ -9,8 +9,9 @@
 #include "drmtest.h"
 #include "igt_debugfs.h"
 #include "igt_sriov_device.h"
-#include "xe/xe_sriov_debugfs.h"
 #include "xe/xe_query.h"
+#include "xe/xe_sriov_debugfs.h"
+#include "xe/xe_sriov_provisioning.h"
 
 #define SRIOV_DEBUGFS_PATH_MAX 96
 
@@ -67,3 +68,139 @@ int xe_sriov_pf_debugfs_attr_open(int pf, unsigned int vf_num, unsigned int gt_n
 
 	return debugfs;
 }
+
+/**
+ * xe_sriov_debugfs_provisioned_attr_name:
+ * @res: The shared resource type
+ *
+ * Returns the name of the debugfs provisioned attribute corresponding
+ * to the given shared resource type.
+ *
+ * Return: A string representing the debugfs provisioned attribute name if the
+ *         resource type is valid, otherwise NULL.
+ */
+const char *xe_sriov_debugfs_provisioned_attr_name(enum xe_sriov_shared_res res)
+{
+	switch (res) {
+	case XE_SRIOV_SHARED_RES_CONTEXTS:
+		return "contexts_provisioned";
+	case XE_SRIOV_SHARED_RES_DOORBELLS:
+		return "doorbells_provisioned";
+	case XE_SRIOV_SHARED_RES_GGTT:
+		return "ggtt_provisioned";
+	case XE_SRIOV_SHARED_RES_LMEM:
+		return "lmem_provisioned";
+	}
+
+	return NULL;
+}
+
+static int parse_provisioned_range(const char *line,
+				   struct xe_sriov_provisioned_range *range,
+				   enum xe_sriov_shared_res res)
+{
+	int ret = -1;
+
+	switch (res) {
+	case XE_SRIOV_SHARED_RES_CONTEXTS:
+	case XE_SRIOV_SHARED_RES_DOORBELLS:
+		if (sscanf(line, "VF%u: %lu-%lu", &range->vf_id, &range->start, &range->end) == 3)
+			ret = 0;
+		break;
+	case XE_SRIOV_SHARED_RES_GGTT:
+		if (sscanf(line, "VF%u: %lx-%lx", &range->vf_id, &range->start, &range->end) == 3)
+			ret = 0;
+		break;
+	case XE_SRIOV_SHARED_RES_LMEM:
+		/* Convert to an inclusive range as is the case for other resources.
+		 * The start is always 0 and the end is the value read - 1.
+		 */
+		if (sscanf(line, "VF%u: %lu", &range->vf_id, &range->end) == 2)
+			ret = 0;
+		if (!range->end)
+			return -1;
+		range->end -= 1;
+		range->start = 0;
+		break;
+	}
+
+	return ret;
+}
+
+/**
+ * xe_sriov_debugfs_pf_read_provisioned_ranges:
+ * @pf_fd: PF device file descriptor
+ * @res: resource
+ * @gt_id: GT number
+ * @ranges: pointer to array of provisioned ranges
+ * @nr_ranges: pointer to number of read provisioned VFs
+ *
+ * Reads provisioned ranges of shared resources.
+ * Allocates the space for ranges and updates
+ * the nr_ranges to the number of read ranges.
+ * The caller should free the allocated space.
+ *
+ * Return: 0 if successful in reading ranges, otherwise negative error code.
+ */
+int xe_sriov_pf_debugfs_read_provisioned_ranges(int pf_fd, enum xe_sriov_shared_res res,
+						unsigned int gt_id,
+						struct xe_sriov_provisioned_range **ranges,
+						unsigned int *nr_ranges)
+{
+	struct xe_sriov_provisioned_range *new_ranges;
+	struct xe_sriov_provisioned_range range;
+	FILE *file;
+	size_t n = 0;
+	const char *fname;
+	char *line = NULL;
+	int fd, ret = 0;
+	ssize_t nread;
+
+	*nr_ranges = 0;
+	*ranges = NULL;
+
+	fname = xe_sriov_debugfs_provisioned_attr_name(res);
+	if (!fname)
+		return -EINVAL;
+
+	fd = xe_sriov_pf_debugfs_attr_open(pf_fd, 0, gt_id, fname, O_RDONLY);
+	if (fd < 0)
+		return -ENOENT;
+	file = fdopen(fd, "r");
+	if (!file) {
+		close(fd);
+		return -errno;
+	}
+
+	while ((nread = getline(&line, &n, file)) != -1) {
+		ret = parse_provisioned_range(line, &range, res);
+		if (ret) {
+			igt_debug("Failed to parse line: %s\n", line);
+			goto cleanup;
+		}
+
+		new_ranges = realloc(*ranges, sizeof(range) * (*nr_ranges + 1));
+		if (!new_ranges) {
+			ret = -ENOMEM;
+			goto cleanup;
+		}
+		*ranges = new_ranges;
+		memcpy(&(*ranges)[*nr_ranges], &range, sizeof(range));
+		(*nr_ranges)++;
+	}
+
+	if (ferror(file))
+		ret = -EIO;
+
+cleanup:
+	free(line);
+	fclose(file);
+
+	if (ret < 0) {
+		free(*ranges);
+		*ranges = NULL;
+		*nr_ranges = 0;
+	}
+
+	return ret;
+}
diff --git a/lib/xe/xe_sriov_debugfs.h b/lib/xe/xe_sriov_debugfs.h
index 9f4ba8f43..856445e76 100644
--- a/lib/xe/xe_sriov_debugfs.h
+++ b/lib/xe/xe_sriov_debugfs.h
@@ -6,7 +6,15 @@
 #ifndef __XE_SRIOV_DEBUGFS_H__
 #define __XE_SRIOV_DEBUGFS_H__
 
+enum xe_sriov_shared_res;
+struct xe_sriov_provisioned_range;
+
 int xe_sriov_pf_debugfs_attr_open(int pf, unsigned int vf_num, unsigned int gt_num,
 				  const char *attr, int mode);
+const char *xe_sriov_debugfs_provisioned_attr_name(enum xe_sriov_shared_res res);
+int xe_sriov_pf_debugfs_read_provisioned_ranges(int pf_fd, enum xe_sriov_shared_res res,
+						unsigned int gt_id,
+						struct xe_sriov_provisioned_range **ranges,
+						unsigned int *nr_ranges);
 
 #endif /* __XE_SRIOV_DEBUGFS_H__ */
-- 
2.31.1