platsmp.c
2.98 KB
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/*
* Copyright 2011-2014 Freescale Semiconductor, Inc.
* Copyright 2011 Linaro Ltd.
*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/init.h>
#include <linux/smp.h>
#include <asm/cacheflush.h>
#include <asm/page.h>
#include <asm/smp_scu.h>
#include <asm/mach/map.h>
#include "common.h"
#include "hardware.h"
#define SCU_STANDBY_ENABLE (1 << 5)
u32 g_diag_reg;
void __iomem *imx_scu_base;
static struct map_desc scu_io_desc __initdata = {
/* .virtual and .pfn are run-time assigned */
.length = SZ_4K,
.type = MT_DEVICE,
};
void __init imx_scu_map_io(void)
{
unsigned long base;
/* Get SCU base */
asm("mrc p15, 4, %0, c15, c0, 0" : "=r" (base));
scu_io_desc.virtual = IMX_IO_P2V(base);
scu_io_desc.pfn = __phys_to_pfn(base);
iotable_init(&scu_io_desc, 1);
imx_scu_base = IMX_IO_ADDRESS(base);
}
void imx_scu_standby_enable(void)
{
u32 val = readl_relaxed(imx_scu_base);
val |= SCU_STANDBY_ENABLE;
writel_relaxed(val, imx_scu_base);
}
static int __cpuinit imx_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
imx_set_cpu_jump(cpu, v7_secondary_startup);
imx_enable_cpu(cpu, true);
return 0;
}
/*
* Initialise the CPU possible map early - this describes the CPUs
* which may be present or become present in the system.
*/
static void __init imx_smp_init_cpus(void)
{
int i, ncores = scu_get_core_count(imx_scu_base);
u32 me = smp_processor_id();
if (setup_max_cpus < ncores)
ncores = (setup_max_cpus) ? setup_max_cpus : 1;
for (i = ncores; i < NR_CPUS; i++)
set_cpu_possible(i, false);
/* Set the SCU CPU Power status for each inactive core. */
for (i = 0; i < NR_CPUS; i++) {
if (i != me)
__raw_writeb(SCU_PM_POWEROFF, imx_scu_base + 0x08 + i);
}
}
void imx_smp_prepare(void)
{
scu_enable(imx_scu_base);
/* Need to enable SCU standby for entering WAIT mode */
imx_scu_standby_enable();
}
static void __init imx_smp_prepare_cpus(unsigned int max_cpus)
{
imx_smp_prepare();
/*
* The diagnostic register holds the errata bits. Mostly bootloader
* does not bring up secondary cores, so that when errata bits are set
* in bootloader, they are set only for boot cpu. But on a SMP
* configuration, it should be equally done on every single core.
* Read the register from boot cpu here, and will replicate it into
* secondary cores when booting them.
*/
asm("mrc p15, 0, %0, c15, c0, 1" : "=r" (g_diag_reg) : : "cc");
__cpuc_flush_dcache_area(&g_diag_reg, sizeof(g_diag_reg));
outer_clean_range(__pa(&g_diag_reg), __pa(&g_diag_reg + 1));
}
struct smp_operations imx_smp_ops __initdata = {
.smp_init_cpus = imx_smp_init_cpus,
.smp_prepare_cpus = imx_smp_prepare_cpus,
.smp_boot_secondary = imx_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = imx_cpu_die,
.cpu_kill = imx_cpu_kill,
#endif
};