blob: 4b73265add495af5e9259015fd63d677cf6f2d50 [file] [log] [blame]
/*
* Copyright (c) 2014-2018, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <assert.h>
#include <string.h>
#include <arch_helpers.h>
#include <common/debug.h>
#include <drivers/arm/css/css_mhu.h>
#include <drivers/arm/css/css_scpi.h>
#include <lib/utils.h>
#include <plat/common/platform.h>
#include <platform_def.h>
#define SCPI_SHARED_MEM_SCP_TO_AP PLAT_CSS_SCP_COM_SHARED_MEM_BASE
#define SCPI_SHARED_MEM_AP_TO_SCP (PLAT_CSS_SCP_COM_SHARED_MEM_BASE \
+ 0x100)
/* Header and payload addresses for commands from AP to SCP */
#define SCPI_CMD_HEADER_AP_TO_SCP \
((scpi_cmd_t *) SCPI_SHARED_MEM_AP_TO_SCP)
#define SCPI_CMD_PAYLOAD_AP_TO_SCP \
((void *) (SCPI_SHARED_MEM_AP_TO_SCP + sizeof(scpi_cmd_t)))
/* Header and payload addresses for responses from SCP to AP */
#define SCPI_RES_HEADER_SCP_TO_AP \
((scpi_cmd_t *) SCPI_SHARED_MEM_SCP_TO_AP)
#define SCPI_RES_PAYLOAD_SCP_TO_AP \
((void *) (SCPI_SHARED_MEM_SCP_TO_AP + sizeof(scpi_cmd_t)))
/* ID of the MHU slot used for the SCPI protocol */
#define SCPI_MHU_SLOT_ID 0
static void scpi_secure_message_start(void)
{
mhu_secure_message_start(SCPI_MHU_SLOT_ID);
}
static void scpi_secure_message_send(size_t payload_size)
{
/*
* Ensure that any write to the SCPI payload area is seen by SCP before
* we write to the MHU register. If these 2 writes were reordered by
* the CPU then SCP would read stale payload data
*/
dmbst();
mhu_secure_message_send(SCPI_MHU_SLOT_ID);
}
static void scpi_secure_message_receive(scpi_cmd_t *cmd)
{
uint32_t mhu_status;
assert(cmd != NULL);
mhu_status = mhu_secure_message_wait();
/* Expect an SCPI message, reject any other protocol */
if (mhu_status != (1 << SCPI_MHU_SLOT_ID)) {
ERROR("MHU: Unexpected protocol (MHU status: 0x%x)\n",
mhu_status);
panic();
}
/*
* Ensure that any read to the SCPI payload area is done after reading
* the MHU register. If these 2 reads were reordered then the CPU would
* read invalid payload data
*/
dmbld();
memcpy(cmd, (void *) SCPI_SHARED_MEM_SCP_TO_AP, sizeof(*cmd));
}
static void scpi_secure_message_end(void)
{
mhu_secure_message_end(SCPI_MHU_SLOT_ID);
}
int scpi_wait_ready(void)
{
scpi_cmd_t scpi_cmd;
VERBOSE("Waiting for SCP_READY command...\n");
/* Get a message from the SCP */
scpi_secure_message_start();
scpi_secure_message_receive(&scpi_cmd);
scpi_secure_message_end();
/* We are expecting 'SCP Ready', produce correct error if it's not */
scpi_status_t status = SCP_OK;
if (scpi_cmd.id != SCPI_CMD_SCP_READY) {
ERROR("Unexpected SCP command: expected command #%u, got command #%u\n",
SCPI_CMD_SCP_READY, scpi_cmd.id);
status = SCP_E_SUPPORT;
} else if (scpi_cmd.size != 0) {
ERROR("SCP_READY command has incorrect size: expected 0, got %u\n",
scpi_cmd.size);
status = SCP_E_SIZE;
}
VERBOSE("Sending response for SCP_READY command\n");
/*
* Send our response back to SCP.
* We are using the same SCPI header, just update the status field.
*/
scpi_cmd.status = status;
scpi_secure_message_start();
memcpy((void *) SCPI_SHARED_MEM_AP_TO_SCP, &scpi_cmd, sizeof(scpi_cmd));
scpi_secure_message_send(0);
scpi_secure_message_end();
return status == SCP_OK ? 0 : -1;
}
void scpi_set_css_power_state(unsigned int mpidr,
scpi_power_state_t cpu_state, scpi_power_state_t cluster_state,
scpi_power_state_t css_state)
{
scpi_cmd_t *cmd;
uint32_t state = 0;
uint32_t *payload_addr;
#if ARM_PLAT_MT
/*
* The current SCPI driver only caters for single-threaded platforms.
* Hence we ignore the thread ID (which is always 0) for such platforms.
*/
state |= (mpidr >> MPIDR_AFF1_SHIFT) & 0x0f; /* CPU ID */
state |= ((mpidr >> MPIDR_AFF2_SHIFT) & 0x0f) << 4; /* Cluster ID */
#else
state |= mpidr & 0x0f; /* CPU ID */
state |= (mpidr & 0xf00) >> 4; /* Cluster ID */
#endif /* ARM_PLAT_MT */
state |= cpu_state << 8;
state |= cluster_state << 12;
state |= css_state << 16;
scpi_secure_message_start();
/* Populate the command header */
cmd = SCPI_CMD_HEADER_AP_TO_SCP;
cmd->id = SCPI_CMD_SET_CSS_POWER_STATE;
cmd->set = SCPI_SET_NORMAL;
cmd->sender = 0;
cmd->size = sizeof(state);
/* Populate the command payload */
payload_addr = SCPI_CMD_PAYLOAD_AP_TO_SCP;
*payload_addr = state;
scpi_secure_message_send(sizeof(state));
/*
* SCP does not reply to this command in order to avoid MHU interrupts
* from the sender, which could interfere with its power state request.
*/
scpi_secure_message_end();
}
/*
* Query and obtain CSS power state from SCP.
*
* In response to the query, SCP returns power states of all CPUs in all
* clusters of the system. The returned response is then filtered based on the
* supplied MPIDR. Power states of requested cluster and CPUs within are updated
* via. supplied non-NULL pointer arguments.
*
* Returns 0 on success, or -1 on errors.
*/
int scpi_get_css_power_state(unsigned int mpidr, unsigned int *cpu_state_p,
unsigned int *cluster_state_p)
{
scpi_cmd_t *cmd;
scpi_cmd_t response;
int power_state, cpu, cluster, rc = -1;
/*
* Extract CPU and cluster membership of the given MPIDR. SCPI caters
* for only up to 0xf clusters, and 8 CPUs per cluster
*/
#if ARM_PLAT_MT
/*
* The current SCPI driver only caters for single-threaded platforms.
* Hence we ignore the thread ID (which is always 0) for such platforms.
*/
cpu = (mpidr >> MPIDR_AFF1_SHIFT) & MPIDR_AFFLVL_MASK;
cluster = (mpidr >> MPIDR_AFF2_SHIFT) & MPIDR_AFFLVL_MASK;
#else
cpu = mpidr & MPIDR_AFFLVL_MASK;
cluster = (mpidr >> MPIDR_AFF1_SHIFT) & MPIDR_AFFLVL_MASK;
#endif /* ARM_PLAT_MT */
if (cpu >= 8 || cluster >= 0xf)
return -1;
scpi_secure_message_start();
/* Populate request headers */
zeromem(SCPI_CMD_HEADER_AP_TO_SCP, sizeof(*cmd));
cmd = SCPI_CMD_HEADER_AP_TO_SCP;
cmd->id = SCPI_CMD_GET_CSS_POWER_STATE;
/*
* Send message and wait for SCP's response
*/
scpi_secure_message_send(0);
scpi_secure_message_receive(&response);
if (response.status != SCP_OK)
goto exit;
/* Validate SCP response */
if (!CHECK_RESPONSE(response, cluster))
goto exit;
/* Extract power states for required cluster */
power_state = *(((uint16_t *) SCPI_RES_PAYLOAD_SCP_TO_AP) + cluster);
if (CLUSTER_ID(power_state) != cluster)
goto exit;
/* Update power state via. pointers */
if (cluster_state_p)
*cluster_state_p = CLUSTER_POWER_STATE(power_state);
if (cpu_state_p)
*cpu_state_p = CPU_POWER_STATE(power_state);
rc = 0;
exit:
scpi_secure_message_end();
return rc;
}
uint32_t scpi_sys_power_state(scpi_system_state_t system_state)
{
scpi_cmd_t *cmd;
uint8_t *payload_addr;
scpi_cmd_t response;
scpi_secure_message_start();
/* Populate the command header */
cmd = SCPI_CMD_HEADER_AP_TO_SCP;
cmd->id = SCPI_CMD_SYS_POWER_STATE;
cmd->set = 0;
cmd->sender = 0;
cmd->size = sizeof(*payload_addr);
/* Populate the command payload */
payload_addr = SCPI_CMD_PAYLOAD_AP_TO_SCP;
*payload_addr = system_state & 0xff;
scpi_secure_message_send(sizeof(*payload_addr));
scpi_secure_message_receive(&response);
scpi_secure_message_end();
return response.status;
}