diff --git a/plat/arm/css/common/css_scpi.c b/plat/arm/css/common/css_scpi.c index 02d573c9f..90a8939d9 100644 --- a/plat/arm/css/common/css_scpi.c +++ b/plat/arm/css/common/css_scpi.c @@ -41,11 +41,18 @@ #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 @@ -163,6 +170,68 @@ void scpi_set_css_power_state(unsigned mpidr, scpi_power_state_t cpu_state, 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 + */ + cpu = mpidr & MPIDR_AFFLVL_MASK; + cluster = (mpidr >> MPIDR_AFF1_SHIFT) & MPIDR_AFFLVL_MASK; + if (cpu >= 8 || cluster >= 0xf) + return -1; + + scpi_secure_message_start(); + + /* Populate request headers */ + cmd = memset(SCPI_CMD_HEADER_AP_TO_SCP, 0, sizeof(*cmd)); + 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; diff --git a/plat/arm/css/common/css_scpi.h b/plat/arm/css/common/css_scpi.h index 4a601f3ef..1fb55e4dd 100644 --- a/plat/arm/css/common/css_scpi.h +++ b/plat/arm/css/common/css_scpi.h @@ -1,5 +1,5 @@ /* - * Copyright (c) 2014-2015, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2014-2016, ARM Limited and Contributors. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: @@ -81,9 +81,34 @@ typedef uint32_t scpi_status_t; typedef enum { SCPI_CMD_SCP_READY = 0x01, SCPI_CMD_SET_CSS_POWER_STATE = 0x03, + SCPI_CMD_GET_CSS_POWER_STATE = 0x04, SCPI_CMD_SYS_POWER_STATE = 0x05 } scpi_command_t; +/* + * Macros to parse SCP response to GET_CSS_POWER_STATE command + * + * [3:0] : cluster ID + * [7:4] : cluster state: 0 = on; 3 = off; rest are reserved + * [15:8]: on/off state for individual CPUs in the cluster + * + * Payload is in little-endian + */ +#define CLUSTER_ID(_resp) ((_resp) & 0xf) +#define CLUSTER_POWER_STATE(_resp) (((_resp) >> 4) & 0xf) + +/* Result is a bit mask of CPU on/off states in the cluster */ +#define CPU_POWER_STATE(_resp) (((_resp) >> 8) & 0xff) + +/* + * For GET_CSS_POWER_STATE, SCP returns the power states of every cluster. The + * size of response depends on the number of clusters in the system. The + * SCP-to-AP payload contains 2 bytes per cluster. Make sure the response is + * large enough to contain power states of a given cluster + */ +#define CHECK_RESPONSE(_resp, _clus) \ + (_resp.size >= (((_clus) + 1) * 2)) + typedef enum { scpi_power_on = 0, scpi_power_retention = 1, @@ -101,6 +126,8 @@ extern void scpi_set_css_power_state(unsigned mpidr, scpi_power_state_t cpu_state, scpi_power_state_t cluster_state, scpi_power_state_t css_state); +int scpi_get_css_power_state(unsigned int mpidr, unsigned int *cpu_state_p, + unsigned int *cluster_state_p); uint32_t scpi_sys_power_state(scpi_system_state_t system_state);