// SPDX-License-Identifier: BSD-2-Clause
/*
 * Copyright (c) 2019-2021, Linaro Limited
 * Copyright (c) 2019-2021, STMicroelectronics
 */
#include <compiler.h>
#include <config.h>
#include <drivers/scmi-msg.h>
#include <kernel/pseudo_ta.h>
#include <pta_scmi_client.h>
#include <stdint.h>
#include <string.h>

static TEE_Result cmd_capabilities(uint32_t ptypes,
				   TEE_Param param[TEE_NUM_PARAMS])
{
	const uint32_t exp_ptypes = TEE_PARAM_TYPES(TEE_PARAM_TYPE_VALUE_OUTPUT,
						    TEE_PARAM_TYPE_NONE,
						    TEE_PARAM_TYPE_NONE,
						    TEE_PARAM_TYPE_NONE);
	uint32_t caps = 0;

	if (ptypes != exp_ptypes)
		return TEE_ERROR_BAD_PARAMETERS;

	if (IS_ENABLED(CFG_SCMI_MSG_SMT))
		caps |= PTA_SCMI_CAPS_SMT_HEADER;
	if (IS_ENABLED(CFG_SCMI_MSG_SHM_MSG))
		caps |= PTA_SCMI_CAPS_MSG_HEADER;

	param[0].value.a = caps;
	param[0].value.b = 0;

	return TEE_SUCCESS;
}

static TEE_Result cmd_process_smt_channel(uint32_t ptypes,
					  TEE_Param params[TEE_NUM_PARAMS])
{
	const uint32_t exp_ptypes = TEE_PARAM_TYPES(TEE_PARAM_TYPE_VALUE_INPUT,
						    TEE_PARAM_TYPE_NONE,
						    TEE_PARAM_TYPE_NONE,
						    TEE_PARAM_TYPE_NONE);
	unsigned int channel_id = params[0].value.a;

	if (ptypes != exp_ptypes)
		return TEE_ERROR_BAD_PARAMETERS;

	if (IS_ENABLED(CFG_SCMI_MSG_SMT)) {
		struct scmi_msg_channel *channel = NULL;

		channel = plat_scmi_get_channel(channel_id);
		if (!channel)
			return TEE_ERROR_BAD_PARAMETERS;

		scmi_smt_threaded_entry(channel_id);

		return TEE_SUCCESS;
	}

	return TEE_ERROR_NOT_SUPPORTED;
}

static TEE_Result cmd_process_smt_message(uint32_t ptypes,
					  TEE_Param params[TEE_NUM_PARAMS])
{
	const uint32_t exp_ptypes = TEE_PARAM_TYPES(TEE_PARAM_TYPE_VALUE_INPUT,
						    TEE_PARAM_TYPE_MEMREF_INOUT,
						    TEE_PARAM_TYPE_NONE,
						    TEE_PARAM_TYPE_NONE);
	unsigned int channel_id = params[0].value.a;
	TEE_Param *param1 = params + 1;

	if (ptypes != exp_ptypes)
		return TEE_ERROR_BAD_PARAMETERS;

	if (IS_ENABLED(CFG_SCMI_MSG_SMT)) {
		struct scmi_msg_channel *channel = NULL;

		if (param1->memref.size < SMT_BUF_SLOT_SIZE)
			return TEE_ERROR_BAD_PARAMETERS;

		channel = plat_scmi_get_channel(channel_id);
		if (!channel)
			return TEE_ERROR_BAD_PARAMETERS;

		/*
		 * Caller provides the buffer, we bind channel to that buffer.
		 * Once message is processed, unbind the buffer since it is
		 * valid only for the current invocation.
		 */
		scmi_smt_set_shared_buffer(channel, param1->memref.buffer);
		scmi_smt_threaded_entry(channel_id);
		scmi_smt_set_shared_buffer(channel, NULL);

		return TEE_SUCCESS;
	}

	return TEE_ERROR_NOT_SUPPORTED;
}

static TEE_Result cmd_process_msg_channel(uint32_t ptypes,
					  TEE_Param params[TEE_NUM_PARAMS])
{
	TEE_Result res = TEE_ERROR_GENERIC;
	const uint32_t exp_pt = TEE_PARAM_TYPES(TEE_PARAM_TYPE_VALUE_INPUT,
						TEE_PARAM_TYPE_MEMREF_INPUT,
						TEE_PARAM_TYPE_MEMREF_OUTPUT,
						TEE_PARAM_TYPE_NONE);
	unsigned int channel_id = params[0].value.a;
	void *in_buf = params[1].memref.buffer;
	size_t in_size = params[1].memref.size;
	void *out_buf = params[2].memref.buffer;
	size_t out_size = params[2].memref.size;

	if (ptypes != exp_pt || !in_buf || !out_buf)
		return TEE_ERROR_BAD_PARAMETERS;

	if (IS_ENABLED(CFG_SCMI_MSG_SHM_MSG)) {
		struct scmi_msg_channel *channel = NULL;

		channel = plat_scmi_get_channel(channel_id);
		if (!channel)
			return TEE_ERROR_BAD_PARAMETERS;

		res = scmi_msg_threaded_entry(channel_id, in_buf, in_size,
					      out_buf, &out_size);
		if (!res)
			params[2].memref.size = out_size;

		return res;
	}

	return TEE_ERROR_NOT_SUPPORTED;
}

static TEE_Result cmd_get_channel_handle(uint32_t ptypes,
					 TEE_Param params[TEE_NUM_PARAMS])
{
	const uint32_t exp_ptypes = TEE_PARAM_TYPES(TEE_PARAM_TYPE_VALUE_INOUT,
						    TEE_PARAM_TYPE_NONE,
						    TEE_PARAM_TYPE_NONE,
						    TEE_PARAM_TYPE_NONE);
	unsigned int channel_id = params[0].value.a;
	unsigned int caps = params[0].value.b;
	const unsigned int supported_caps = PTA_SCMI_CAPS_SMT_HEADER |
					    PTA_SCMI_CAPS_MSG_HEADER;

	if (ptypes != exp_ptypes || caps & ~supported_caps)
		return TEE_ERROR_BAD_PARAMETERS;

	if (IS_ENABLED(CFG_SCMI_MSG_DRIVERS)) {
		struct scmi_msg_channel *channel = NULL;

		if ((!IS_ENABLED(CFG_SCMI_MSG_SMT) &&
		     caps & PTA_SCMI_CAPS_SMT_HEADER) ||
		    (!IS_ENABLED(CFG_SCMI_MSG_SHM_MSG) &&
		     caps & PTA_SCMI_CAPS_MSG_HEADER))
			return TEE_ERROR_NOT_SUPPORTED;

		channel = plat_scmi_get_channel(channel_id);
		if (!channel)
			return TEE_ERROR_BAD_PARAMETERS;

		channel->threaded = true;
		params[0].value.a = scmi_smt_channel_handle(channel_id);

		return TEE_SUCCESS;
	}

	return TEE_ERROR_NOT_SUPPORTED;
}

static TEE_Result pta_scmi_open_session(uint32_t ptypes __unused,
					TEE_Param par[TEE_NUM_PARAMS] __unused,
					void **session __unused)
{
	struct ts_session *ts = ts_get_current_session();
	struct tee_ta_session *ta_session = to_ta_session(ts);

	/* Only REE kernel is allowed to access SCMI resources */
	if (ta_session->clnt_id.login != TEE_LOGIN_REE_KERNEL) {
		DMSG("Expecting TEE_LOGIN_REE_KERNEL");
		return TEE_ERROR_ACCESS_DENIED;
	}

	if (IS_ENABLED(CFG_SCMI_MSG_SMT) || IS_ENABLED(CFG_SCMI_MSG_SHM_MSG))
		return TEE_SUCCESS;

	return TEE_ERROR_NOT_SUPPORTED;
}

static TEE_Result pta_scmi_invoke_command(void *session __unused, uint32_t cmd,
					  uint32_t ptypes,
					  TEE_Param params[TEE_NUM_PARAMS])
{
	FMSG("SCMI command %#"PRIx32" ptypes %#"PRIx32, cmd, ptypes);

	switch (cmd) {
	case PTA_SCMI_CMD_CAPABILITIES:
		return cmd_capabilities(ptypes, params);
	case PTA_SCMI_CMD_PROCESS_SMT_CHANNEL:
		return cmd_process_smt_channel(ptypes, params);
	case PTA_SCMI_CMD_PROCESS_SMT_CHANNEL_MESSAGE:
		return cmd_process_smt_message(ptypes, params);
	case PTA_SCMI_CMD_PROCESS_MSG_CHANNEL:
		return cmd_process_msg_channel(ptypes, params);
	case PTA_SCMI_CMD_GET_CHANNEL_HANDLE:
		return cmd_get_channel_handle(ptypes, params);
	default:
		return TEE_ERROR_NOT_SUPPORTED;
	}
}

pseudo_ta_register(.uuid = PTA_SCMI_UUID, .name = PTA_SCMI_NAME,
		   .flags = PTA_DEFAULT_FLAGS | TA_FLAG_CONCURRENT |
			    TA_FLAG_DEVICE_ENUM,
		   .open_session_entry_point = pta_scmi_open_session,
		   .invoke_command_entry_point = pta_scmi_invoke_command);