97 lines
2.4 KiB
C
97 lines
2.4 KiB
C
/*
|
|
* linux/arch/arm/kernel/smp_scu.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/io.h>
|
|
|
|
#include <asm/smp_plat.h>
|
|
#include <asm/smp_scu.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/cputype.h>
|
|
|
|
#define SCU_CTRL 0x00
|
|
#define SCU_ENABLE (1 << 0)
|
|
#define SCU_STANDBY_ENABLE (1 << 5)
|
|
#define SCU_CONFIG 0x04
|
|
#define SCU_CPU_STATUS 0x08
|
|
#define SCU_INVALIDATE 0x0c
|
|
#define SCU_FPGA_REVISION 0x10
|
|
|
|
#ifdef CONFIG_SMP
|
|
/*
|
|
* Get the number of CPU cores from the SCU configuration
|
|
*/
|
|
unsigned int __init scu_get_core_count(void __iomem *scu_base)
|
|
{
|
|
unsigned int ncores = readl_relaxed(scu_base + SCU_CONFIG);
|
|
return (ncores & 0x03) + 1;
|
|
}
|
|
|
|
/*
|
|
* Enable the SCU
|
|
*/
|
|
void scu_enable(void __iomem *scu_base)
|
|
{
|
|
u32 scu_ctrl;
|
|
|
|
#ifdef CONFIG_ARM_ERRATA_764369
|
|
/* Cortex-A9 only */
|
|
if ((read_cpuid_id() & 0xff0ffff0) == 0x410fc090) {
|
|
scu_ctrl = readl_relaxed(scu_base + 0x30);
|
|
if (!(scu_ctrl & 1))
|
|
writel_relaxed(scu_ctrl | 0x1, scu_base + 0x30);
|
|
}
|
|
#endif
|
|
|
|
scu_ctrl = readl_relaxed(scu_base + SCU_CTRL);
|
|
/* already enabled? */
|
|
if (scu_ctrl & SCU_ENABLE)
|
|
return;
|
|
|
|
scu_ctrl |= SCU_ENABLE;
|
|
|
|
/* Cortex-A9 earlier than r2p0 has no standby bit in SCU */
|
|
if ((read_cpuid_id() & 0xff0ffff0) == 0x410fc090 &&
|
|
(read_cpuid_id() & 0x00f0000f) >= 0x00200000)
|
|
scu_ctrl |= SCU_STANDBY_ENABLE;
|
|
|
|
writel_relaxed(scu_ctrl, scu_base + SCU_CTRL);
|
|
|
|
/*
|
|
* Ensure that the data accessed by CPU0 before the SCU was
|
|
* initialised is visible to the other CPUs.
|
|
*/
|
|
flush_cache_all();
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Set the executing CPUs power mode as defined. This will be in
|
|
* preparation for it executing a WFI instruction.
|
|
*
|
|
* This function must be called with preemption disabled, and as it
|
|
* has the side effect of disabling coherency, caches must have been
|
|
* flushed. Interrupts must also have been disabled.
|
|
*/
|
|
int scu_power_mode(void __iomem *scu_base, unsigned int mode)
|
|
{
|
|
unsigned int val;
|
|
int cpu = MPIDR_AFFINITY_LEVEL(cpu_logical_map(smp_processor_id()), 0);
|
|
|
|
if (mode > 3 || mode == 1 || cpu > 3)
|
|
return -EINVAL;
|
|
|
|
val = readb_relaxed(scu_base + SCU_CPU_STATUS + cpu) & ~0x03;
|
|
val |= mode;
|
|
writeb_relaxed(val, scu_base + SCU_CPU_STATUS + cpu);
|
|
|
|
return 0;
|
|
}
|