drivers/scmi-msg: support for reset domain protocol

Adds SCMI reset domain protocol support in the SCMI message drivers
as defined in SCMI specification v2.0 [1]. Not all the messages
defined in the specification are supported.

scmi_msg_get_rd_handler() sanitizes the message_id value
against any speculative use of reset domain ID as a index since by
SCMI specification, IDs are indices.

This implementation is based on the OP-TEE project implementation [2]
itself based on the SCP-firmware implementation [3] of the SCMI
protocol server side.

Link: [1] http://infocenter.arm.com/help/topic/com.arm.doc.den0056a/DEN0056A_System_Control_and_Management_Interface.pdf
Link: [2] https://github.com/OP-TEE/optee_os/commit/56a1f10ed99d683ee3a8af29b6147a59a99ef3e0
Link: [3] https://github.com/ARM-software/SCP-firmware.git



Change-Id: If7cf13de40a815dedb40dcd5af8b6bb6725d9078
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

drivers/st/scmi-msg/common.h

@@ -13,6 +13,7 @@
 
 #include "base.h"
 #include "clock.h"
+#include "reset_domain.h"
 
 #define SCMI_VERSION			0x20000U
 #define SCMI_IMPL_VERSION		0U
@@ -102,6 +103,13 @@ scmi_msg_handler_t scmi_msg_get_base_handler(struct scmi_msg *msg);
  */
 scmi_msg_handler_t scmi_msg_get_clock_handler(struct scmi_msg *msg);
 
+/*
+ * scmi_msg_get_rstd_handler - Return a handler for a reset domain message
+ * @msg - message to process
+ * Return a function handler for the message or NULL
+ */
+scmi_msg_handler_t scmi_msg_get_rstd_handler(struct scmi_msg *msg);
+
 /*
  * Process Read, process and write response for input SCMI message
  *

drivers/st/scmi-msg/entry.c

@@ -44,6 +44,9 @@ void scmi_process_message(struct scmi_msg *msg)
 	case SCMI_PROTOCOL_ID_CLOCK:
 		handler = scmi_msg_get_clock_handler(msg);
 		break;
+	case SCMI_PROTOCOL_ID_RESET_DOMAIN:
+		handler = scmi_msg_get_rstd_handler(msg);
+		break;
 	default:
 		break;
 	}

drivers/st/scmi-msg/reset_domain.c

+// SPDX-License-Identifier: BSD-3-Clause
+/*
+ * Copyright (c) 2015-2020, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2019-2020, Linaro Limited
+ */
+#include <cdefs.h>
+#include <string.h>
+
+#include <drivers/st/scmi-msg.h>
+#include <drivers/st/scmi.h>
+#include <lib/utils.h>
+#include <lib/utils_def.h>
+
+#include "common.h"
+
+static bool message_id_is_supported(unsigned int message_id);
+
+#pragma weak plat_scmi_rstd_count
+#pragma weak plat_scmi_rstd_get_name
+#pragma weak plat_scmi_rstd_autonomous
+#pragma weak plat_scmi_rstd_set_state
+
+size_t plat_scmi_rstd_count(unsigned int agent_id __unused)
+{
+	return 0U;
+}
+
+const char *plat_scmi_rstd_get_name(unsigned int agent_id __unused,
+				  unsigned int scmi_id __unused)
+{
+	return NULL;
+}
+
+int32_t plat_scmi_rstd_autonomous(unsigned int agent_id __unused,
+				unsigned int scmi_id __unused,
+				unsigned int state __unused)
+{
+	return SCMI_NOT_SUPPORTED;
+}
+
+int32_t plat_scmi_rstd_set_state(unsigned int agent_id __unused,
+			       unsigned int scmi_id __unused,
+			       bool assert_not_deassert __unused)
+{
+	return SCMI_NOT_SUPPORTED;
+}
+
+static void report_version(struct scmi_msg *msg)
+{
+	struct scmi_protocol_version_p2a return_values = {
+		.status = SCMI_SUCCESS,
+		.version = SCMI_PROTOCOL_VERSION_RESET_DOMAIN,
+	};
+
+	if (msg->in_size != 0U) {
+		scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
+		return;
+	}
+
+	scmi_write_response(msg, &return_values, sizeof(return_values));
+}
+
+static void report_attributes(struct scmi_msg *msg)
+{
+	struct scmi_protocol_attributes_p2a return_values = {
+		.status = SCMI_SUCCESS,
+		.attributes = plat_scmi_rstd_count(msg->agent_id),
+	};
+
+	if (msg->in_size != 0U) {
+		scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
+		return;
+	}
+
+	scmi_write_response(msg, &return_values, sizeof(return_values));
+}
+
+static void report_message_attributes(struct scmi_msg *msg)
+{
+	struct scmi_protocol_message_attributes_a2p *in_args = (void *)msg->in;
+	struct scmi_protocol_message_attributes_p2a return_values = {
+		.status = SCMI_SUCCESS,
+		/* For this protocol, attributes shall be zero */
+		.attributes = 0U,
+	};
+
+	if (msg->in_size != sizeof(*in_args)) {
+		scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
+		return;
+	}
+
+	if (!message_id_is_supported(in_args->message_id)) {
+		scmi_status_response(msg, SCMI_NOT_FOUND);
+		return;
+	}
+
+	scmi_write_response(msg, &return_values, sizeof(return_values));
+}
+
+static void reset_domain_attributes(struct scmi_msg *msg)
+{
+	struct scmi_reset_domain_attributes_a2p *in_args = (void *)msg->in;
+	struct scmi_reset_domain_attributes_p2a return_values;
+	const char *name = NULL;
+	unsigned int domain_id = 0U;
+
+	if (msg->in_size != sizeof(*in_args)) {
+		scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
+		return;
+	}
+
+	domain_id = SPECULATION_SAFE_VALUE(in_args->domain_id);
+
+	if (domain_id >= plat_scmi_rstd_count(msg->agent_id)) {
+		scmi_status_response(msg, SCMI_INVALID_PARAMETERS);
+		return;
+	}
+
+	name = plat_scmi_rstd_get_name(msg->agent_id, domain_id);
+	if (name == NULL) {
+		scmi_status_response(msg, SCMI_NOT_FOUND);
+		return;
+	}
+
+	zeromem(&return_values, sizeof(return_values));
+	COPY_NAME_IDENTIFIER(return_values.name, name);
+	return_values.status = SCMI_SUCCESS;
+	return_values.flags = 0U; /* Async and Notif are not supported */
+	return_values.latency = SCMI_RESET_DOMAIN_ATTR_UNK_LAT;
+
+	scmi_write_response(msg, &return_values, sizeof(return_values));
+}
+
+static void reset_request(struct scmi_msg *msg)
+{
+	struct scmi_reset_domain_request_a2p *in_args = (void *)msg->in;
+	struct scmi_reset_domain_request_p2a out_args = {
+		.status = SCMI_SUCCESS,
+	};
+	unsigned int domain_id = 0U;
+
+	if (msg->in_size != sizeof(*in_args)) {
+		scmi_status_response(msg, SCMI_PROTOCOL_ERROR);
+		return;
+	}
+
+	domain_id = SPECULATION_SAFE_VALUE(in_args->domain_id);
+
+	if (domain_id >= plat_scmi_rstd_count(msg->agent_id)) {
+		scmi_status_response(msg, SCMI_NOT_FOUND);
+		return;
+	}
+
+	if ((in_args->flags & SCMI_RESET_DOMAIN_AUTO) != 0U) {
+		out_args.status = plat_scmi_rstd_autonomous(msg->agent_id,
+							  domain_id,
+							  in_args->reset_state);
+	} else if ((in_args->flags & SCMI_RESET_DOMAIN_EXPLICIT) != 0U) {
+		out_args.status = plat_scmi_rstd_set_state(msg->agent_id,
+							 domain_id, true);
+	} else {
+		out_args.status = plat_scmi_rstd_set_state(msg->agent_id,
+							 domain_id, false);
+	}
+
+	if (out_args.status != SCMI_SUCCESS) {
+		scmi_status_response(msg, out_args.status);
+	} else {
+		scmi_write_response(msg, &out_args, sizeof(out_args));
+	}
+}
+
+static const scmi_msg_handler_t scmi_rstd_handler_table[] = {
+	[SCMI_PROTOCOL_VERSION] = report_version,
+	[SCMI_PROTOCOL_ATTRIBUTES] = report_attributes,
+	[SCMI_PROTOCOL_MESSAGE_ATTRIBUTES] = report_message_attributes,
+	[SCMI_RESET_DOMAIN_ATTRIBUTES] = reset_domain_attributes,
+	[SCMI_RESET_DOMAIN_REQUEST] = reset_request,
+};
+
+static bool message_id_is_supported(unsigned int message_id)
+{
+	return (message_id < ARRAY_SIZE(scmi_rstd_handler_table)) &&
+	       (scmi_rstd_handler_table[message_id] != NULL);
+}
+
+scmi_msg_handler_t scmi_msg_get_rstd_handler(struct scmi_msg *msg)
+{
+	unsigned int message_id = SPECULATION_SAFE_VALUE(msg->message_id);
+
+	if (message_id >= ARRAY_SIZE(scmi_rstd_handler_table)) {
+		VERBOSE("Reset domain handle not found %u\n", msg->message_id);
+		return NULL;
+	}
+
+	return scmi_rstd_handler_table[message_id];
+}

drivers/st/scmi-msg/reset_domain.h

+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Copyright (c) 2015-2019, Arm Limited and Contributors. All rights reserved.
+ * Copyright (c) 2019, Linaro Limited
+ */
+#ifndef SCMI_MSG_RESET_DOMAIN_H
+#define SCMI_MSG_RESET_DOMAIN_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include <lib/utils_def.h>
+
+#define SCMI_PROTOCOL_VERSION_RESET_DOMAIN	0x10000U
+
+#define SCMI_RESET_STATE_ARCH			BIT(31)
+#define SCMI_RESET_STATE_IMPL			0U
+
+/*
+ * Identifiers of the SCMI Reset Domain Management Protocol commands
+ */
+enum scmi_reset_domain_command_id {
+	SCMI_RESET_DOMAIN_ATTRIBUTES = 0x03,
+	SCMI_RESET_DOMAIN_REQUEST = 0x04,
+	SCMI_RESET_DOMAIN_NOTIFY = 0x05,
+};
+
+/*
+ * Identifiers of the SCMI Reset Domain Management Protocol responses
+ */
+enum scmi_reset_domain_response_id {
+	SCMI_RESET_ISSUED = 0x00,
+	SCMI_RESET_COMPLETE = 0x04,
+};
+
+/*
+ * PROTOCOL_ATTRIBUTES
+ */
+
+#define SCMI_RESET_DOMAIN_COUNT_MASK		GENMASK_32(15, 0)
+
+struct scmi_reset_domain_protocol_attributes_p2a {
+	int32_t status;
+	uint32_t attributes;
+};
+
+/* Value for scmi_reset_domain_attributes_p2a:flags */
+#define SCMI_RESET_DOMAIN_ATTR_ASYNC		BIT(31)
+#define SCMI_RESET_DOMAIN_ATTR_NOTIF		BIT(30)
+
+/* Value for scmi_reset_domain_attributes_p2a:latency */
+#define SCMI_RESET_DOMAIN_ATTR_UNK_LAT		0x7fffffffU
+#define SCMI_RESET_DOMAIN_ATTR_MAX_LAT		0x7ffffffeU
+
+/* Macro for scmi_reset_domain_attributes_p2a:name */
+#define SCMI_RESET_DOMAIN_ATTR_NAME_SZ		16U
+
+struct scmi_reset_domain_attributes_a2p {
+	uint32_t domain_id;
+};
+
+struct scmi_reset_domain_attributes_p2a {
+	int32_t status;
+	uint32_t flags;
+	uint32_t latency;
+	char name[SCMI_RESET_DOMAIN_ATTR_NAME_SZ];
+};
+
+/*
+ * RESET
+ */
+
+/* Values for scmi_reset_domain_request_a2p:flags */
+#define SCMI_RESET_DOMAIN_ASYNC			BIT(2)
+#define SCMI_RESET_DOMAIN_EXPLICIT		BIT(1)
+#define SCMI_RESET_DOMAIN_AUTO			BIT(0)
+
+struct scmi_reset_domain_request_a2p {
+	uint32_t domain_id;
+	uint32_t flags;
+	uint32_t reset_state;
+};
+
+struct scmi_reset_domain_request_p2a {
+	int32_t status;
+};
+
+/*
+ * RESET_NOTIFY
+ */
+
+/* Values for scmi_reset_notify_p2a:flags */
+#define SCMI_RESET_DOMAIN_DO_NOTIFY		BIT(0)
+
+struct scmi_reset_domain_notify_a2p {
+	uint32_t domain_id;
+	uint32_t notify_enable;
+};
+
+struct scmi_reset_domain_notify_p2a {
+	int32_t status;
+};
+
+/*
+ * RESET_COMPLETE
+ */
+
+struct scmi_reset_domain_complete_p2a {
+	int32_t status;
+	uint32_t domain_id;
+};
+
+/*
+ * RESET_ISSUED
+ */
+
+struct scmi_reset_domain_issued_p2a {
+	uint32_t domain_id;
+	uint32_t reset_state;
+};
+
+#endif /* SCMI_MSG_RESET_DOMAIN_H */

include/drivers/st/scmi-msg.h

@@ -141,4 +141,41 @@ int32_t plat_scmi_clock_get_state(unsigned int agent_id, unsigned int scmi_id);
 int32_t plat_scmi_clock_set_state(unsigned int agent_id, unsigned int scmi_id,
 				  bool enable_not_disable);
 
+/* Handlers for SCMI Reset Domain protocol services */
+
+/*
+ * Return number of reset domains for the agent
+ * @agent_id: SCMI agent ID
+ * Return number of reset domains
+ */
+size_t plat_scmi_rstd_count(unsigned int agent_id);
+
+/*
+ * Get reset domain string ID (aka name)
+ * @agent_id: SCMI agent ID
+ * @scmi_id: SCMI reset domain ID
+ * Return pointer to name or NULL
+ */
+const char *plat_scmi_rstd_get_name(unsigned int agent_id, unsigned int scmi_id);
+
+/*
+ * Perform a reset cycle on a target reset domain
+ * @agent_id: SCMI agent ID
+ * @scmi_id: SCMI reset domain ID
+ * @state: Target reset state (see SCMI specification, 0 means context loss)
+ * Return a compliant SCMI error code
+ */
+int32_t plat_scmi_rstd_autonomous(unsigned int agent_id, unsigned int scmi_id,
+				  unsigned int state);
+
+/*
+ * Assert or deassert target reset domain
+ * @agent_id: SCMI agent ID
+ * @scmi_id: SCMI reset domain ID
+ * @assert_not_deassert: Assert domain if true, otherwise deassert domain
+ * Return a compliant SCMI error code
+ */
+int32_t plat_scmi_rstd_set_state(unsigned int agent_id, unsigned int scmi_id,
+				 bool assert_not_deassert);
+
 #endif /* SCMI_MSG_H */