linux/arch/arm/mach-actions/platsmp.c

157 lines
3.6 KiB
C

/*
* Actions Semi Leopard
*
* This file is based on arm realview smp platform.
*
* Copyright 2012 Actions Semi Inc.
* Author: Actions Semi, Inc.
*
* Copyright (c) 2017 Andreas Färber
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*/
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/smp.h>
#include <linux/soc/actions/owl-sps.h>
#include <asm/cacheflush.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
#define OWL_CPU1_ADDR 0x50
#define OWL_CPU1_FLAG 0x5c
#define OWL_CPUx_FLAG_BOOT 0x55aa
#define OWL_SPS_PG_CTL_PWR_CPU2 BIT(5)
#define OWL_SPS_PG_CTL_PWR_CPU3 BIT(6)
#define OWL_SPS_PG_CTL_ACK_CPU2 BIT(21)
#define OWL_SPS_PG_CTL_ACK_CPU3 BIT(22)
static void __iomem *scu_base_addr;
static void __iomem *sps_base_addr;
static void __iomem *timer_base_addr;
static int ncores;
static int s500_wakeup_secondary(unsigned int cpu)
{
int ret;
if (cpu > 3)
return -EINVAL;
/* The generic PM domain driver is not available this early. */
switch (cpu) {
case 2:
ret = owl_sps_set_pg(sps_base_addr,
OWL_SPS_PG_CTL_PWR_CPU2,
OWL_SPS_PG_CTL_ACK_CPU2, true);
if (ret)
return ret;
break;
case 3:
ret = owl_sps_set_pg(sps_base_addr,
OWL_SPS_PG_CTL_PWR_CPU3,
OWL_SPS_PG_CTL_ACK_CPU3, true);
if (ret)
return ret;
break;
}
/* wait for CPUx to run to WFE instruction */
udelay(200);
writel(__pa_symbol(secondary_startup),
timer_base_addr + OWL_CPU1_ADDR + (cpu - 1) * 4);
writel(OWL_CPUx_FLAG_BOOT,
timer_base_addr + OWL_CPU1_FLAG + (cpu - 1) * 4);
dsb_sev();
mb();
return 0;
}
static int s500_smp_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
int ret;
ret = s500_wakeup_secondary(cpu);
if (ret)
return ret;
udelay(10);
smp_send_reschedule(cpu);
writel(0, timer_base_addr + OWL_CPU1_ADDR + (cpu - 1) * 4);
writel(0, timer_base_addr + OWL_CPU1_FLAG + (cpu - 1) * 4);
return 0;
}
static void __init s500_smp_prepare_cpus(unsigned int max_cpus)
{
struct device_node *node;
node = of_find_compatible_node(NULL, NULL, "actions,s500-timer");
if (!node) {
pr_err("%s: missing timer\n", __func__);
return;
}
timer_base_addr = of_iomap(node, 0);
if (!timer_base_addr) {
pr_err("%s: could not map timer registers\n", __func__);
return;
}
node = of_find_compatible_node(NULL, NULL, "actions,s500-sps");
if (!node) {
pr_err("%s: missing sps\n", __func__);
return;
}
sps_base_addr = of_iomap(node, 0);
if (!sps_base_addr) {
pr_err("%s: could not map sps registers\n", __func__);
return;
}
if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) {
node = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
if (!node) {
pr_err("%s: missing scu\n", __func__);
return;
}
scu_base_addr = of_iomap(node, 0);
if (!scu_base_addr) {
pr_err("%s: could not map scu registers\n", __func__);
return;
}
/*
* While the number of cpus is gathered from dt, also get the
* number of cores from the scu to verify this value when
* booting the cores.
*/
ncores = scu_get_core_count(scu_base_addr);
pr_debug("%s: ncores %d\n", __func__, ncores);
scu_enable(scu_base_addr);
}
}
static const struct smp_operations s500_smp_ops __initconst = {
.smp_prepare_cpus = s500_smp_prepare_cpus,
.smp_boot_secondary = s500_smp_boot_secondary,
};
CPU_METHOD_OF_DECLARE(s500_smp, "actions,s500-smp", &s500_smp_ops);