blob: 509afe8f29bdd641f44ba750d58aa467da2dae23 [file] [log] [blame]
/*
* Copyright (c) 2014-2016, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch_helpers.h>
#include <assert.h>
#include <bakery_lock.h>
#include <css_def.h>
#include <mmio.h>
#include <plat_arm.h>
#include <platform_def.h>
#include "css_mhu.h"
/* SCP MHU secure channel registers */
#define SCP_INTR_S_STAT 0x200
#define SCP_INTR_S_SET 0x208
#define SCP_INTR_S_CLEAR 0x210
/* CPU MHU secure channel registers */
#define CPU_INTR_S_STAT 0x300
#define CPU_INTR_S_SET 0x308
#define CPU_INTR_S_CLEAR 0x310
ARM_INSTANTIATE_LOCK
/* Weak definition may be overridden in specific CSS based platform */
#pragma weak plat_arm_pwrc_setup
/*
* Slot 31 is reserved because the MHU hardware uses this register bit to
* indicate a non-secure access attempt. The total number of available slots is
* therefore 31 [30:0].
*/
#define MHU_MAX_SLOT_ID 30
void mhu_secure_message_start(unsigned int slot_id)
{
assert(slot_id <= MHU_MAX_SLOT_ID);
arm_lock_get();
/* Make sure any previous command has finished */
while (mmio_read_32(PLAT_CSS_MHU_BASE + CPU_INTR_S_STAT) &
(1 << slot_id))
;
}
void mhu_secure_message_send(unsigned int slot_id)
{
assert(slot_id <= MHU_MAX_SLOT_ID);
assert(!(mmio_read_32(PLAT_CSS_MHU_BASE + CPU_INTR_S_STAT) &
(1 << slot_id)));
/* Send command to SCP */
mmio_write_32(PLAT_CSS_MHU_BASE + CPU_INTR_S_SET, 1 << slot_id);
}
uint32_t mhu_secure_message_wait(void)
{
/* Wait for response from SCP */
uint32_t response;
while (!(response = mmio_read_32(PLAT_CSS_MHU_BASE + SCP_INTR_S_STAT)))
;
return response;
}
void mhu_secure_message_end(unsigned int slot_id)
{
assert(slot_id <= MHU_MAX_SLOT_ID);
/*
* Clear any response we got by writing one in the relevant slot bit to
* the CLEAR register
*/
mmio_write_32(PLAT_CSS_MHU_BASE + SCP_INTR_S_CLEAR, 1 << slot_id);
arm_lock_release();
}
void mhu_secure_init(void)
{
arm_lock_init();
/*
* The STAT register resets to zero. Ensure it is in the expected state,
* as a stale or garbage value would make us think it's a message we've
* already sent.
*/
assert(mmio_read_32(PLAT_CSS_MHU_BASE + CPU_INTR_S_STAT) == 0);
}
void plat_arm_pwrc_setup(void)
{
mhu_secure_init();
}