linux-stable/arch/arm/mach-imx/platsmp.c
Shawn Guo 087bb28329 ARM: imx: replicate the diagnostic register of boot cpu into secondary cores
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.
Set up the diagnostic register for secondary cores by replicating
the register from boot cpu.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Dirk Behme <dirk.behme@de.bosch.com>
2013-05-12 21:39:18 +08:00

107 lines
2.6 KiB
C

/*
* Copyright 2011 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;
static void __iomem *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);
scu_base = IMX_IO_ADDRESS(base);
}
void imx_scu_standby_enable(void)
{
u32 val = readl_relaxed(scu_base);
val |= SCU_STANDBY_ENABLE;
writel_relaxed(val, 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;
ncores = scu_get_core_count(scu_base);
for (i = ncores; i < NR_CPUS; i++)
set_cpu_possible(i, false);
}
void imx_smp_prepare(void)
{
scu_enable(scu_base);
}
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
};