[PATCH 6/8] lib/igt_drm_netlink: add event notify subscription and event wait support

Added event notification support with subscribe for an error-notify event and
wait for the event notification functionalities.

Signed-off-by: Ravi Kishore Koppuravuri <[email protected]>
---
 lib/igt_drm_netlink.c | 108 ++++++++++++++++++++++++++++++++++++++++++
 lib/igt_drm_netlink.h |   6 +++
 2 files changed, 114 insertions(+)

diff --git a/lib/igt_drm_netlink.c b/lib/igt_drm_netlink.c
index 4738090af..b72fb343d 100644
--- a/lib/igt_drm_netlink.c
+++ b/lib/igt_drm_netlink.c
@@ -6,6 +6,7 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <errno.h>
+#include <poll.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -31,6 +32,26 @@ static int ras_command_cb(struct nl_msg *msg, void *arg)
 	switch (gnlh->cmd) {
 	case DRM_RAS_CMD_SET_ERROR_THRESHOLD:
 		break;
+	case DRM_RAS_CMD_ERROR_EVENT: {
+		struct nlattr *attrs[DRM_RAS_A_ERROR_EVENT_ATTRS_MAX + 1];
+
+		ret = genlmsg_parse(nlh, 0, attrs,
+				    DRM_RAS_A_ERROR_EVENT_ATTRS_MAX, NULL);
+		if (ret < 0)
+			return NL_SKIP;
+
+		if (!attrs[DRM_RAS_A_ERROR_EVENT_ATTRS_NODE_ID] ||
+		    !attrs[DRM_RAS_A_ERROR_EVENT_ATTRS_ERROR_ID] ||
+		    !attrs[DRM_RAS_A_ERROR_EVENT_ATTRS_ERROR_VALUE])
+			return NL_SKIP;
+
+		ctx->event_node_id = nla_get_u32(attrs[DRM_RAS_A_ERROR_EVENT_ATTRS_NODE_ID]);
+		ctx->event_error_id = nla_get_u32(attrs[DRM_RAS_A_ERROR_EVENT_ATTRS_ERROR_ID]);
+		ctx->event_error_value =
+			nla_get_u32(attrs[DRM_RAS_A_ERROR_EVENT_ATTRS_ERROR_VALUE]);
+		ctx->event_received = true;
+		break;
+	}
 	case DRM_RAS_CMD_GET_ERROR_COUNTER: {
 		struct nlattr *attrs[DRM_RAS_A_ERROR_COUNTER_ATTRS_MAX + 1];
 
@@ -171,6 +192,10 @@ int init_app_context(struct app_context *ctx)
 	ctx->error_id = UINT32_MAX;
 	ctx->error_value = 0;
 	ctx->error_threshold = 0;
+	ctx->event_node_id = UINT32_MAX;
+	ctx->event_error_id = UINT32_MAX;
+	ctx->event_error_value = 0;
+	ctx->event_received = false;
 	ctx->family_id = -1;
 
 	return 0;
@@ -186,6 +211,10 @@ void cleanup_app_context(struct app_context *ctx)
 	ctx->error_id = UINT32_MAX;
 	ctx->error_value = 0;
 	ctx->error_threshold = 0;
+	ctx->event_node_id = UINT32_MAX;
+	ctx->event_error_id = UINT32_MAX;
+	ctx->event_error_value = 0;
+	ctx->event_received = false;
 	ctx->family_id = -1;
 }
 
@@ -319,3 +348,82 @@ int set_error_threshold(struct app_context *ctx)
 
 	return 0;
 }
+
+int subscribe_error_notify(struct app_context *ctx, const char *notify_group_name)
+{
+	int grp_id;
+	int ret;
+
+	if (!ctx || !ctx->sock || ctx->family_id < 0 ||
+	    !notify_group_name || notify_group_name[0] == '\0')
+		return -EINVAL;
+
+	grp_id = genl_ctrl_resolve_grp(ctx->sock,
+				       DRM_RAS_FAMILY_NAME,
+				       notify_group_name);
+	if (grp_id < 0)
+		return grp_id;
+
+	ret = nl_socket_add_membership(ctx->sock, grp_id);
+	if (ret < 0)
+		return ret;
+
+	igt_debug("Subscribed to DRM RAS multicast group '%s' (id=%d).\n",
+		  notify_group_name, grp_id);
+
+	return 0;
+}
+
+int wait_for_error_notify_event(struct app_context *ctx, int timeout_ms)
+{
+	struct nl_cb *cb;
+	struct pollfd pfd;
+	int ret;
+
+	if (!ctx || !ctx->sock || ctx->family_id < 0)
+		return -EINVAL;
+
+	if (timeout_ms < -1)
+		return -EINVAL;
+
+	cb = nl_cb_alloc(NL_CB_DEFAULT);
+	if (!cb)
+		return -ENOMEM;
+
+	ret = nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, ras_command_cb, ctx);
+	if (ret < 0) {
+		nl_cb_put(cb);
+		return ret;
+	}
+
+	ctx->event_received = false;
+
+	pfd.fd = nl_socket_get_fd(ctx->sock);
+	pfd.events = POLLIN;
+	pfd.revents = 0;
+
+	ret = poll(&pfd, 1, timeout_ms);
+	if (ret == 0) {
+		nl_cb_put(cb);
+		return -ETIMEDOUT;
+	}
+
+	if (ret < 0) {
+		ret = -errno;
+		nl_cb_put(cb);
+		return ret;
+	}
+
+	ret = nl_recvmsgs(ctx->sock, cb);
+	nl_cb_put(cb);
+	if (ret < 0)
+		return ret;
+
+	if (!ctx->event_received)
+		return -ENOMSG;
+
+	igt_debug("Received error-notify event: node_id=%u error_id=%u value=%u\n",
+		  ctx->event_node_id, ctx->event_error_id, ctx->event_error_value);
+
+	return 0;
+}
diff --git a/lib/igt_drm_netlink.h b/lib/igt_drm_netlink.h
index c44486ffa..b04221a23 100644
--- a/lib/igt_drm_netlink.h
+++ b/lib/igt_drm_netlink.h
@@ -24,6 +24,10 @@ struct app_context {
 	uint32_t error_id;
 	uint32_t error_value;
 	uint32_t error_threshold;
+	uint32_t event_node_id;
+	uint32_t event_error_id;
+	uint32_t event_error_value;
+	bool event_received;
 	int family_id;
 };
 
@@ -34,6 +38,8 @@ int init_nl_socket(struct app_context *ctx);
 int get_error_counter(struct app_context *ctx);
 int get_error_threshold(struct app_context *ctx);
 int set_error_threshold(struct app_context *ctx);
+int subscribe_error_notify(struct app_context *ctx, const char *notify_group_name);
+int wait_for_error_notify_event(struct app_context *ctx, int timeout_ms);
 
 #endif /* IGT_DRM_NETLINK_H */
 
-- 
2.34.1