/*
* Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
* http://www.samsung.com
*
* Cloned from linux/arch/arm/mach-vexpress/platsmp.c
*
* Copyright (C) 2002 ARM Ltd.
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/jiffies.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <linux/of_address.h>
#include <asm/cacheflush.h>
#include <asm/cp15.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
#include <asm/firmware.h>
#include <mach/map.h>
#include "common.h"
#include "regs-pmu.h"
extern void exynos4_secondary_startup(void);
/*
* Set or clear the USE_DELAYED_RESET_ASSERTION option, set on Exynos4 SoCs
* during hot-(un)plugging CPUx.
*
* The feature can be cleared safely during first boot of secondary CPU.
*
* Exynos4 SoCs require setting USE_DELAYED_RESET_ASSERTION during powering
* down a CPU so the CPU idle clock down feature could properly detect global
* idle state when CPUx is off.
*/
static void exynos_set_delayed_reset_assertion(u32 core_id, bool enable)
{
if (soc_is_exynos4()) {
unsigned int tmp;
tmp = pmu_raw_readl(EXYNOS_ARM_CORE_OPTION(core_id));
if (enable)
tmp |= S5P_USE_DELAYED_RESET_ASSERTION;
else
tmp &= ~(S5P_USE_DELAYED_RESET_ASSERTION);
pmu_raw_writel(tmp, EXYNOS_ARM_CORE_OPTION(core_id));
}
}
#ifdef CONFIG_HOTPLUG_CPU
static inline void cpu_leave_lowpower(u32 core_id)
{
unsigned int v;
asm volatile(
"mrc p15, 0, %0, c1, c0, 0\n"
" orr %0, %0, %1\n"
" mcr p15, 0, %0, c1, c0, 0\n"
" mrc p15, 0, %0, c1, c0, 1\n"
" orr %0, %0, %2\n"
" mcr p15, 0, %0, c1, c0, 1\n"
: "=&r" (v)
: "Ir" (CR_C), "Ir" (0x40)
: "cc");
exynos_set_delayed_reset_assertion(core_id, false);
}
static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
{
u32 mpidr = cpu_logical_map(cpu);
u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
for (;;) {
/* Turn the CPU off on next WFI instruction. */
exynos_cpu_power_down(core_id);
/*
* Exynos4 SoCs require setting
* USE_DELAYED_RESET_ASSERTION so the CPU idle
* clock down feature could properly detect
* global idle state when CPUx is off.
*/
exynos_set_delayed_reset_assertion(core_id, true);
wfi();
if (pen_release == core_id) {
/*
* OK, proper wakeup, we're done
*/
break;
}
/*
* Getting here, means that we have come out of WFI without
* having been woken up - this shouldn't happen
*
* Just note it happening - when we're woken, we can report
* its occurrence.
*/
(*spurious)++;
}
}
#endif /* CONFIG_HOTPLUG_CPU */
/**
* exynos_core_power_down : power down the specified cpu
* @cpu : the cpu to power down
*
* Power down the specified cpu. The sequence must be finished by a
* call to cpu_do_idle()
*
*/
void exynos_cpu_power_down(int cpu)
{
if (cpu == 0 && (of_machine_is_compatible("samsung,exynos5420") ||
of_machine_is_compatible("samsung,exynos5800"))) {
/*
* Bypass power down for CPU0 during suspend. Check for
* the SYS_PWR_REG value to decide if we are suspending
* the system.
*/
int val = pmu_raw_readl(EXYNOS5_ARM_CORE0_SYS_PWR_REG);
if (!(val & S5P_CORE_LOCAL_PWR_EN))
return;
}
pmu_raw_writel(0, EXYNOS_ARM_CORE_CONFIGURATION(cpu));
}
/**
* exynos_cpu_power_up : power up the specified cpu
* @cpu : the cpu to power up
*
* Power up the specified cpu
*/
void exynos_cpu_power_up(int cpu)
{
pmu_raw_writel(S5P_CORE_LOCAL_PWR_EN,
EXYNOS_ARM_CORE_CONFIGURATION(cpu));
}
/**
* exynos_cpu_power_state : returns the power state of the cpu
* @cpu : the cpu to retrieve the power state from
*
*/
int exynos_cpu_power_state(int cpu)
{
return (pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(cpu)) &
S5P_CORE_LOCAL_PWR_EN);
}
/**
* exynos_cluster_power_down : power down the specified cluster
* @cluster : the cluster to power down
*/
void exynos_cluster_power_down(int cluster)
{
pmu_raw_writel(0, EXYNOS_COMMON_CONFIGURATION(cluster));
}
/**
* exynos_cluster_power_up : power up the specified cluster
* @cluster : the cluster to power up
*/
void exynos_cluster_power_up(int cluster)
{
pmu_raw_writel(S5P_CORE_LOCAL_PWR_EN,
EXYNOS_COMMON_CONFIGURATION(cluster));
}
/**
* exynos_cluster_power_state : returns the power state of the cluster
* @cluster : the cluster to retrieve the power state from
*
*/
int exynos_cluster_power_state(int cluster)
{
return (pmu_raw_readl(EXYNOS_COMMON_STATUS(cluster)) &
S5P_CORE_LOCAL_PWR_EN);
}
static inline void __iomem *cpu_boot_reg_base(void)
{
if (soc_is_exynos4210() && samsung_rev() == EXYNOS4210_REV_1_1)
return pmu_base_addr + S5P_INFORM5;
return sysram_base_addr;
}
static inline void __iomem *cpu_boot_reg(int cpu)
{
void __iomem *boot_reg;
boot_reg = cpu_boot_reg_base();
if (!boot_reg)
return ERR_PTR(-ENODEV);
if (soc_is_exynos4412())
boot_reg += 4*cpu;
else if (soc_is_exynos5420() || soc_is_exynos5800())
boot_reg += 4;
return boot_reg;
}
/*
* Set wake up by local power mode and execute software reset for given core.
*
* Currently this is needed only when booting secondary CPU on Exynos3250.
*/
static void exynos_core_restart(u32 core_id)
{
u32 val;
if (!of_machine_is_compatible("samsung,exynos3250"))
return;
val = pmu_raw_readl(EXYNOS_ARM_CORE_STATUS(core_id));
val |= S5P_CORE_WAKEUP_FROM_LOCAL_CFG;
pmu_raw_writel(val, EXYNOS_ARM_CORE_STATUS(core_id));
pr_info("CPU%u: Software reset\n", core_id);
pmu_raw_writel(EXYNOS_CORE_PO_RESET(core_id), EXYNOS_SWRESET);
}
/*
* Write pen_release in a way that is guaranteed to be visible to all
* observers, irrespective of whether they're taking part in coherency
* or not. This is necessary for the hotplug code to work reliably.
*/
static void write_pen_release(int val)
{
pen_release = val;
smp_wmb();
sync_cache_w(&pen_release);
}
static void __iomem *scu_base_addr(void)
{
return (void __iomem *)(S5P_VA_SCU);
}
static DEFINE_SPINLOCK(boot_lock);
static void exynos_secondary_init(unsigned int cpu)
{
/*
* let the primary processor know we're out of the
* pen, then head off into the C entry point
*/
write_pen_release(-1);
/*
* Synchronise with the boot thread.
*/
spin_lock(&boot_lock);
spin_unlock(&boot_lock);
}
static int exynos_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
unsigned long timeout;
u32 mpidr = cpu_logical_map(cpu);
u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
int ret = -ENOSYS;
/*
* Set synchronisation state between this boot processor
* and the secondary one
*/
spin_lock(&boot_lock);
/*
* The secondary processor is waiting to be released from
* the holding pen - release it, then wait for it to flag
* that it has been released by resetting pen_release.
*
* Note that "pen_release" is the hardware CPU core ID, whereas
* "cpu" is Linux's internal ID.
*/
write_pen_release(core_id);
if (!exynos_cpu_power_state(core_id)) {
exynos_cpu_power_up(core_id);
timeout = 10;
/* wait max 10 ms until cpu1 is on */
while (exynos_cpu_power_state(core_id)
!= S5P_CORE_LOCAL_PWR_EN) {
if (timeout-- == 0)
break;
mdelay(1);
}
if (timeout == 0) {
printk(KERN_ERR "cpu1 power enable failed");
spin_unlock(&boot_lock);
return -ETIMEDOUT;
}
}
exynos_core_restart(core_id);
/*
* Send the secondary CPU a soft interrupt, thereby causing
* the boot monitor to read the system wide flags register,
* and branch to the address found there.
*/
timeout = jiffies + (1 * HZ);
while (time_before(jiffies, timeout)) {
unsigned long boot_addr;
smp_rmb();
boot_addr = virt_to_phys(exynos4_secondary_startup);
/*
* Try to set boot address using firmware first
* and fall back to boot register if it fails.
*/
ret = call_firmware_op(set_cpu_boot_addr, core_id, boot_addr);
if (ret && ret != -ENOSYS)
goto fail;
if (ret == -ENOSYS) {
void __iomem *boot_reg = cpu_boot_reg(core_id);
if (IS_ERR(boot_reg)) {
ret = PTR_ERR(boot_reg);
goto fail;
}
__raw_writel(boot_addr, boot_reg);
}
call_firmware_op(cpu_boot, core_id);
arch_send_wakeup_ipi_mask(cpumask_of(cpu));
if (pen_release == -1)
break;
udelay(10);
}
/* No harm if this is called during first boot of secondary CPU */
exynos_set_delayed_reset_assertion(core_id, false);
/*
* now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
fail:
spin_unlock(&boot_lock);
return pen_release != -1 ? ret : 0;
}
/*
* Initialise the CPU possible map early - this describes the CPUs
* which may be present or become present in the system.
*/
static void __init exynos_smp_init_cpus(void)
{
void __iomem *scu_base = scu_base_addr();
unsigned int i, ncores;
if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
ncores = scu_base ? scu_get_core_count(scu_base) : 1;
else
/*
* CPU Nodes are passed thru DT and set_cpu_possible
* is set by "arm_dt_init_cpu_maps".
*/
return;
/* sanity check */
if (ncores > nr_cpu_ids) {
pr_warn("SMP: %u cores greater than maximum (%u), clipping\n",
ncores, nr_cpu_ids);
ncores = nr_cpu_ids;
}
for (i = 0; i < ncores; i++)
set_cpu_possible(i, true);
}
static void __init exynos_smp_prepare_cpus(unsigned int max_cpus)
{
int i;
exynos_sysram_init();
if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9)
scu_enable(scu_base_addr());
/*
* Write the address of secondary startup into the
* system-wide flags register. The boot monitor waits
* until it receives a soft interrupt, and then the
* secondary CPU branches to this address.
*
* Try using firmware operation first and fall back to
* boot register if it fails.
*/
for (i = 1; i < max_cpus; ++i) {
unsigned long boot_addr;
u32 mpidr;
u32 core_id;
int ret;
mpidr = cpu_logical_map(i);
core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
boot_addr = virt_to_phys(exynos4_secondary_startup);
ret = call_firmware_op(set_cpu_boot_addr, core_id, boot_addr);
if (ret && ret != -ENOSYS)
break;
if (ret == -ENOSYS) {
void __iomem *boot_reg = cpu_boot_reg(core_id);
if (IS_ERR(boot_reg))
break;
__raw_writel(boot_addr, boot_reg);
}
}
}
#ifdef CONFIG_HOTPLUG_CPU
/*
* platform-specific code to shutdown a CPU
*
* Called with IRQs disabled
*/
static void exynos_cpu_die(unsigned int cpu)
{
int spurious = 0;
u32 mpidr = cpu_logical_map(cpu);
u32 core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0);
v7_exit_coherency_flush(louis);
platform_do_lowpower(cpu, &spurious);
/*
* bring this CPU back into the world of cache
* coherency, and then restore interrupts
*/
cpu_leave_lowpower(core_id);
if (spurious)
pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
}
#endif /* CONFIG_HOTPLUG_CPU */
struct smp_operations exynos_smp_ops __initdata = {
.smp_init_cpus = exynos_smp_init_cpus,
.smp_prepare_cpus = exynos_smp_prepare_cpus,
.smp_secondary_init = exynos_secondary_init,
.smp_boot_secondary = exynos_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = exynos_cpu_die,
#endif
};
