[RFC PATCH v3 13/13] firmware: arm_scmi: Add Base notifications support

[Cristian Marussi <cristian.marussi@arm.com>]

Make SCMI Base protocol register with the notification core.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
V2 --> V3
- added handle awareness
V1 --> V2
- simplified .set_notify_enabled() implementation moving the ALL_SRCIDs
  logic out of protocol. ALL_SRCIDs logic is now in charge of the
  notification core, together with proper reference counting of enables
- switched to devres protocol-registration
---
 drivers/firmware/arm_scmi/base.c | 109 +++++++++++++++++++++++++++++++
 include/linux/scmi_protocol.h    |   8 +++
 2 files changed, 117 insertions(+)

diff --git a/drivers/firmware/arm_scmi/base.c b/drivers/firmware/arm_scmi/base.c
index ce7d9203e41b..0d4bbf313a4a 100644
--- a/drivers/firmware/arm_scmi/base.c
+++ b/drivers/firmware/arm_scmi/base.c
@@ -6,6 +6,9 @@
  */
 
 #include "common.h"
+#include "notify.h"
+
+#define SCMI_BASE_NUM_SOURCES	1
 
 enum scmi_base_protocol_cmd {
 	BASE_DISCOVER_VENDOR = 0x3,
@@ -29,6 +32,19 @@ struct scmi_msg_resp_base_attributes {
 	__le16 reserved;
 };
 
+struct scmi_msg_base_error_notify {
+	__le32 event_control;
+#define BASE_TP_NOTIFY_ALL	BIT(0)
+};
+
+struct scmi_base_error_notify_payld {
+	__le32 agent_id;
+	__le32 error_status;
+#define IS_FATAL_ERROR(x)	((x) & BIT(31))
+#define ERROR_CMD_COUNT(x)	FIELD_GET(GENMASK(9, 0), (x))
+	__le64 msg_reports[8192];
+};
+
 /**
  * scmi_base_attributes_get() - gets the implementation details
  *	that are associated with the base protocol.
@@ -222,6 +238,93 @@ static int scmi_base_discover_agent_get(const struct scmi_handle *handle,
 	return ret;
 }
 
+static int scmi_base_error_notify(const struct scmi_handle *handle, bool enable)
+{
+	int ret;
+	u32 evt_cntl = enable ? BASE_TP_NOTIFY_ALL : 0;
+	struct scmi_xfer *t;
+	struct scmi_msg_base_error_notify *cfg;
+
+	ret = scmi_xfer_get_init(handle, BASE_NOTIFY_ERRORS,
+				 SCMI_PROTOCOL_BASE, sizeof(*cfg), 0, &t);
+	if (ret)
+		return ret;
+
+	cfg = t->tx.buf;
+	cfg->event_control = cpu_to_le32(evt_cntl);
+
+	ret = scmi_do_xfer(handle, t);
+
+	scmi_xfer_put(handle, t);
+	return ret;
+}
+
+static bool scmi_base_set_notify_enabled(const struct scmi_handle *handle,
+					 u8 evt_id, u32 src_id, bool enable)
+{
+	int ret;
+
+	ret = scmi_base_error_notify(handle, enable);
+	if (ret)
+		pr_warn("SCMI Notifications - Proto:%X - FAIL_ENABLED - evt[%X] ret:%d\n",
+			SCMI_PROTOCOL_BASE, evt_id, ret);
+
+	return !ret ? true : false;
+}
+
+static void *scmi_base_fill_custom_report(u8 evt_id, u64 timestamp,
+					  const void *payld, size_t payld_sz,
+					  void *report, u32 *src_id)
+{
+	void *rep = NULL;
+
+	switch (evt_id) {
+	case BASE_ERROR_EVENT:
+	{
+		int i;
+		const struct scmi_base_error_notify_payld *p = payld;
+		struct scmi_base_error_report *r = report;
+
+		/*
+		 * BaseError notification payload is variable in size but
+		 * up to a maximum length determined by the struct ponted by p.
+		 * Instead payld_sz is the effective length of this notification
+		 * payload so cannot be greater of the maximum allowed size as
+		 * pointed by p.
+		 */
+		if (sizeof(*p) < payld_sz)
+			break;
+
+		r->timestamp = timestamp;
+		r->agent_id = le32_to_cpu(p->agent_id);
+		r->fatal = IS_FATAL_ERROR(le32_to_cpu(p->error_status));
+		r->cmd_count = ERROR_CMD_COUNT(le32_to_cpu(p->error_status));
+		for (i = 0; i < r->cmd_count; i++)
+			r->reports[i] = le64_to_cpu(p->msg_reports[i]);
+		*src_id = 0;
+		rep = r;
+		break;
+	}
+	default:
+		break;
+	}
+
+	return rep;
+}
+
+static const struct scmi_event base_events[] = {
+	{
+		.evt_id = BASE_ERROR_EVENT,
+		.max_payld_sz = 8192,
+		.max_report_sz = sizeof(struct scmi_base_error_report),
+	},
+};
+
+static const struct scmi_protocol_event_ops base_event_ops = {
+	.set_notify_enabled = scmi_base_set_notify_enabled,
+	.fill_custom_report = scmi_base_fill_custom_report,
+};
+
 int scmi_base_protocol_init(struct scmi_handle *h)
 {
 	int id, ret;
@@ -256,6 +359,12 @@ int scmi_base_protocol_init(struct scmi_handle *h)
 	dev_dbg(dev, "Found %d protocol(s) %d agent(s)\n", rev->num_protocols,
 		rev->num_agents);
 
+	scmi_register_protocol_events(handle,
+				      SCMI_PROTOCOL_BASE, (4 * PAGE_SIZE),
+				      &base_event_ops, base_events,
+				      ARRAY_SIZE(base_events),
+				      SCMI_BASE_NUM_SOURCES);
+
 	for (id = 0; id < rev->num_agents; id++) {
 		scmi_base_discover_agent_get(handle, id, name);
 		dev_dbg(dev, "Agent %d: %s\n", id, name);
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 91c5fdf567d5..3a1bc8014f51 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -420,4 +420,12 @@ struct scmi_reset_issued_report {
 	u32	reset_state;
 };
 
+struct scmi_base_error_report {
+	ktime_t	timestamp;
+	u32	agent_id;
+	bool	fatal;
+	u16	cmd_count;
+	u64	reports[8192];
+};
+
 #endif /* _LINUX_SCMI_PROTOCOL_H */
-- 
2.17.1