[PATCH v4 3/6] lib/xe/xe_query: introduce helpers for device query

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

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

There are two flawors, to fulfill current usage patterns:
- xe_query_device_may_fail - returns NULL if query is not supported,
- xe_query_device - asserts on error otherwise returns valid pointer.

Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com>
---
 lib/xe/xe_query.c | 43 +++++++++++++++++++++++++++++++++++++++++++
 lib/xe/xe_query.h | 20 ++++++++++++++++++++
 2 files changed, 63 insertions(+)

diff --git a/lib/xe/xe_query.c b/lib/xe/xe_query.c
index a3fab133e6c4d9f949564b47cc817383bee7a568..f3c9de4aa219162610af6becb6c3c02500187099 100644
--- a/lib/xe/xe_query.c
+++ b/lib/xe/xe_query.c
@@ -25,6 +25,49 @@
 #include "xe_query.h"
 #include "xe_ioctl.h"
 
+/**
+ * xe_query_device_may_fail:
+ * @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
+ *
+ * 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. If @query is not supported
+ * function returns NULL. On any other error it asserts.
+ */
+void *xe_query_device_may_fail(int fd, uint32_t type, uint32_t *size)
+{
+	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)
+		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..3e4d73e01b922b47f29731d3cbccc72f67b4c4e1 100644
--- a/lib/xe/xe_query.h
+++ b/lib/xe/xe_query.h
@@ -143,9 +143,29 @@ 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_may_fail(int fd, uint32_t type, uint32_t *size);
 int xe_query_pxp_status(int fd);
 int xe_wait_for_pxp_init(int fd);
 
+/**
+ * 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
+ *
+ * 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. If @query is not supported
+ * or on any other error it asserts.
+ */
+static inline void *xe_query_device(int fd, uint32_t type, uint32_t *size)
+{
+	void *data = xe_query_device_may_fail(fd, type, size);
+
+	igt_assert(data);
+	return data;
+}
+
 struct xe_device *xe_device_get(int fd);
 void xe_device_put(int fd);
 

-- 
2.43.0