linux/arch/arm/mach-imx/src.c
Shawn Guo 2f3edfd7e2 ARM: imx: fix sync issue between imx_cpu_die and imx_cpu_kill
There is a sync issue with hotplug operation.  It's possible that when
imx_cpu_kill gets running on primary core, the imx_cpu_die execution
on the core which is to be killed hasn't been finished yet.  The problem
will very likely be hit when running suspend without no_console_suspend
setting on kernel cmdline.

It uses cpu jumping argument register to sync imx_cpu_die and
imx_cpu_kill.  The register will be set in imx_cpu_die and imx_cpu_kill
will wait for the register being cleared to actually kill the cpu.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: <stable@vger.kernel.org>
2013-03-26 20:25:45 +08:00

88 lines
2.1 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/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/smp.h>
#include <asm/smp_plat.h>
#define SRC_SCR 0x000
#define SRC_GPR1 0x020
#define BP_SRC_SCR_WARM_RESET_ENABLE 0
#define BP_SRC_SCR_CORE1_RST 14
#define BP_SRC_SCR_CORE1_ENABLE 22
static void __iomem *src_base;
void imx_enable_cpu(int cpu, bool enable)
{
u32 mask, val;
cpu = cpu_logical_map(cpu);
mask = 1 << (BP_SRC_SCR_CORE1_ENABLE + cpu - 1);
val = readl_relaxed(src_base + SRC_SCR);
val = enable ? val | mask : val & ~mask;
writel_relaxed(val, src_base + SRC_SCR);
}
void imx_set_cpu_jump(int cpu, void *jump_addr)
{
cpu = cpu_logical_map(cpu);
writel_relaxed(virt_to_phys(jump_addr),
src_base + SRC_GPR1 + cpu * 8);
}
u32 imx_get_cpu_arg(int cpu)
{
cpu = cpu_logical_map(cpu);
return readl_relaxed(src_base + SRC_GPR1 + cpu * 8 + 4);
}
void imx_set_cpu_arg(int cpu, u32 arg)
{
cpu = cpu_logical_map(cpu);
writel_relaxed(arg, src_base + SRC_GPR1 + cpu * 8 + 4);
}
void imx_src_prepare_restart(void)
{
u32 val;
/* clear enable bits of secondary cores */
val = readl_relaxed(src_base + SRC_SCR);
val &= ~(0x7 << BP_SRC_SCR_CORE1_ENABLE);
writel_relaxed(val, src_base + SRC_SCR);
/* clear persistent entry register of primary core */
writel_relaxed(0, src_base + SRC_GPR1);
}
void __init imx_src_init(void)
{
struct device_node *np;
u32 val;
np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-src");
src_base = of_iomap(np, 0);
WARN_ON(!src_base);
/*
* force warm reset sources to generate cold reset
* for a more reliable restart
*/
val = readl_relaxed(src_base + SRC_SCR);
val &= ~(1 << BP_SRC_SCR_WARM_RESET_ENABLE);
writel_relaxed(val, src_base + SRC_SCR);
}