[PATCH v3 3/8] lib/xe/xe_query: introduce helper for device query

[Andrzej Hajda <andrzej.hajda@intel.com>]

The helper abstracts out common bits of DRM_XE_DEVICE_QUERY_HWCONFIG ioctl:
- query data size,
- alloc memory,
- get data,
- error checks,
- valgrind annotations.

Since almost all users of DRM_XE_DEVICE_QUERY_HWCONFIG use asserts for
error checking helper uses them as well.

Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com>
---
 lib/xe/xe_query.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 lib/xe/xe_query.h |  1 +
 2 files changed, 48 insertions(+)

diff --git a/lib/xe/xe_query.c b/lib/xe/xe_query.c
index a3fab133e6c4d9f949564b47cc817383bee7a568..4d46b36fa9754fc48e50633dd79f06b935ce8300 100644
--- a/lib/xe/xe_query.c
+++ b/lib/xe/xe_query.c
@@ -25,6 +25,53 @@
 #include "xe_query.h"
 #include "xe_ioctl.h"
 
+/**
+ * xe_query_device:
+ * @fd: xe device fd
+ * @type: query type, one of DRM_XE_DEVICE_QUERY_* values
+ * @size: pointer to get size of returned data, can be NULL
+ * @can_fail: bool indicating if query can fail
+ *
+ * Calls DRM_IOCTL_XE_DEVICE_QUERY ioctl to query device information
+ * about specified @type. Returns pointer to malloc'ed data, which
+ * should be freed later by the user. @can_fail indicates if function
+ * should return NULL or assert if @query is not supported.
+ * On any other error it asserts.
+ */
+void *xe_query_device(int fd, uint32_t type, uint32_t *size, bool can_fail)
+{
+	struct drm_xe_device_query query = {
+		.extensions = 0,
+		.query = type,
+		.size = 0,
+		.data = 0,
+	};
+	void *data = NULL;
+
+	/* In case of unsupported query xe driver usually returns error,
+	 * but in case of HWCONFIG it can also return query.size == 0
+	 * on older platforms.
+	 */
+	if (igt_ioctl(fd, DRM_IOCTL_XE_DEVICE_QUERY, &query) || !query.size)
+		igt_assert(can_fail);
+	if (!query.size)
+		goto skip_query;
+
+	data = malloc(query.size);
+	igt_assert(data);
+
+	query.data = to_user_pointer(data);
+	igt_assert_eq(igt_ioctl(fd, DRM_IOCTL_XE_DEVICE_QUERY, &query), 0);
+
+	VG(VALGRIND_MAKE_MEM_DEFINED(data, query.size));
+
+skip_query:
+	if (size)
+		*size = query.size;
+
+	return data;
+}
+
 static struct drm_xe_query_config *xe_query_config_new(int fd)
 {
 	struct drm_xe_query_config *config;
diff --git a/lib/xe/xe_query.h b/lib/xe/xe_query.h
index 4f1c0687133c03b81ba53f95457c55860e5ce194..b1483f5eb6ac330454e719423dee52013b4b6137 100644
--- a/lib/xe/xe_query.h
+++ b/lib/xe/xe_query.h
@@ -143,6 +143,7 @@ uint16_t xe_gt_get_tile_id(int fd, int gt);
 uint16_t xe_tile_get_main_gt_id(int fd, uint8_t tile);
 uint32_t *xe_hwconfig_lookup_value(int fd, enum intel_hwconfig attribute, uint32_t *len);
 uint32_t xe_hwconfig_get_u32(int fd, enum intel_hwconfig attribute, uint32_t default_value);
+void *xe_query_device(int fd, uint32_t type, uint32_t *size, bool can_fail);
 int xe_query_pxp_status(int fd);
 int xe_wait_for_pxp_init(int fd);
 

-- 
2.43.0