ipi.c

/*
 * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

/*
 * Xilinx IPI agent registers access management
 */

#include <errno.h>
#include <string.h>

#include <common/debug.h>
#include <common/runtime_svc.h>
#include <drivers/delay_timer.h>
#include <lib/bakery_lock.h>
#include <lib/mmio.h>

#include <ipi.h>
#include <plat_ipi.h>
#include <plat_private.h>

/*********************************************************************
 * Macros definitions
 ********************************************************************/

/* IPI registers offsets macros */
#define IPI_TRIG_OFFSET 0x00U
#define IPI_OBR_OFFSET  0x04U
#define IPI_ISR_OFFSET  0x10U
#define IPI_IMR_OFFSET  0x14U
#define IPI_IER_OFFSET  0x18U
#define IPI_IDR_OFFSET  0x1CU

/* IPI register start offset */
#define IPI_REG_BASE(I) (ipi_table[(I)].ipi_reg_base)

/* IPI register bit mask */
#define IPI_BIT_MASK(I) (ipi_table[(I)].ipi_bit_mask)

/* IPI Timeout */
#define TIMEOUT_COUNT_US	U(0x4000)

/* IPI configuration table */
const static struct ipi_config *ipi_table;

/* Total number of IPI */
static uint32_t ipi_total;

/**
 * ipi_config_init() - Initialize IPI configuration data
 *
 * @ipi_config_table  - IPI configuration table
 * @ipi_total - Total number of IPI available
 *
 */
void ipi_config_table_init(const struct ipi_config *ipi_config_table,
			   uint32_t total_ipi)
{
	ipi_table = ipi_config_table;
	ipi_total = total_ipi;
}

/* is_ipi_mb_within_range() - verify if IPI mailbox is within range
 *
 * @local  - local IPI ID
 * @remote - remote IPI ID
 *
 * return - 1 if within range, 0 if not
 */
static inline int is_ipi_mb_within_range(uint32_t local, uint32_t remote)
{
	int ret = 1;

	if (remote >= ipi_total || local >= ipi_total)
		ret = 0;

	return ret;
}

/**
 * ipi_mb_validate() - validate IPI mailbox access
 *
 * @local  - local IPI ID
 * @remote - remote IPI ID
 * @is_secure - indicate if the requester is from secure software
 *
 * return - 0 success, negative value for errors
 */
int ipi_mb_validate(uint32_t local, uint32_t remote, unsigned int is_secure)
{
	int ret = 0;

	if (!is_ipi_mb_within_range(local, remote))
		ret = -EINVAL;
	else if (IPI_IS_SECURE(local) && !is_secure)
		ret = -EPERM;
	else if (IPI_IS_SECURE(remote) && !is_secure)
		ret = -EPERM;

	return ret;
}

/**
 * ipi_mb_open() - Open IPI mailbox.
 *
 * @local  - local IPI ID
 * @remote - remote IPI ID
 *
 */
void ipi_mb_open(uint32_t local, uint32_t remote)
{
	mmio_write_32(IPI_REG_BASE(local) + IPI_IDR_OFFSET,
		      IPI_BIT_MASK(remote));
	mmio_write_32(IPI_REG_BASE(local) + IPI_ISR_OFFSET,
		      IPI_BIT_MASK(remote));
}

/**
 * ipi_mb_release() - Open IPI mailbox.
 *
 * @local  - local IPI ID
 * @remote - remote IPI ID
 *
 */
void ipi_mb_release(uint32_t local, uint32_t remote)
{
	mmio_write_32(IPI_REG_BASE(local) + IPI_IDR_OFFSET,
		      IPI_BIT_MASK(remote));
}

/**
 * ipi_mb_enquire_status() - Enquire IPI mailbox status
 *
 * @local  - local IPI ID
 * @remote - remote IPI ID
 *
 * return - 0 idle, positive value for pending sending or receiving,
 *          negative value for errors
 */
int ipi_mb_enquire_status(uint32_t local, uint32_t remote)
{
	int ret = 0;
	uint32_t status;

	status = mmio_read_32(IPI_REG_BASE(local) + IPI_OBR_OFFSET);
	if (status & IPI_BIT_MASK(remote))
		ret |= IPI_MB_STATUS_SEND_PENDING;
	status = mmio_read_32(IPI_REG_BASE(local) + IPI_ISR_OFFSET);
	if (status & IPI_BIT_MASK(remote))
		ret |= IPI_MB_STATUS_RECV_PENDING;

	return ret;
}

/* ipi_mb_notify() - Trigger IPI mailbox notification
 *
 * @local - local IPI ID
 * @remote - remote IPI ID
 * @is_blocking - if to trigger the notification in blocking mode or not.
 *
 * return - 0 - Success or Error incase of timeout
 * It sets the remote bit in the IPI agent trigger register.
 *
 */
int ipi_mb_notify(uint32_t local, uint32_t remote, uint32_t is_blocking)
{
	uint32_t status;
	const unsigned int timeout_count = TIMEOUT_COUNT_US;
	uint64_t timeout;

	mmio_write_32(IPI_REG_BASE(local) + IPI_TRIG_OFFSET,
		      IPI_BIT_MASK(remote));
	if (is_blocking) {
		timeout = timeout_init_us(timeout_count);
		do {
			status = mmio_read_32(IPI_REG_BASE(local) +
					      IPI_OBR_OFFSET);
			if (timeout_elapsed(timeout)) {
				return -ETIMEDOUT;
			}
		} while (status & IPI_BIT_MASK(remote));
	}

	return 0;
}

/* ipi_mb_ack() - Ack IPI mailbox notification from the other end
 *
 * @local - local IPI ID
 * @remote - remote IPI ID
 *
 * It will clear the remote bit in the isr register.
 *
 */
void ipi_mb_ack(uint32_t local, uint32_t remote)
{
	mmio_write_32(IPI_REG_BASE(local) + IPI_ISR_OFFSET,
		      IPI_BIT_MASK(remote));
}

/* ipi_mb_disable_irq() - Disable IPI mailbox notification interrupt
 *
 * @local - local IPI ID
 * @remote - remote IPI ID
 *
 * It will mask the remote bit in the idr register.
 *
 */
void ipi_mb_disable_irq(uint32_t local, uint32_t remote)
{
	mmio_write_32(IPI_REG_BASE(local) + IPI_IDR_OFFSET,
		      IPI_BIT_MASK(remote));
}

/* ipi_mb_enable_irq() - Enable IPI mailbox notification interrupt
 *
 * @local - local IPI ID
 * @remote - remote IPI ID
 *
 * It will mask the remote bit in the idr register.
 *
 */
void ipi_mb_enable_irq(uint32_t local, uint32_t remote)
{
	mmio_write_32(IPI_REG_BASE(local) + IPI_IER_OFFSET,
		      IPI_BIT_MASK(remote));
}