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| author | Shawn Guo <shawn.guo@linaro.org> | 2013-03-26 09:46:07 +0100 |
|---|---|---|
| committer | Shawn Guo <shawn.guo@linaro.org> | 2013-03-26 13:25:45 +0100 |
| commit | 2f3edfd7e27ad4206acbc2ae99c9df5f46353024 (patch) | |
| tree | 91a1caefb205cb5fe9fc28de6cddd9490540c9b0 /arch/arm | |
| parent | ARM: imx: add dependency check for DEBUG_IMX_UART_PORT (diff) | |
| download | linux-2f3edfd7e27ad4206acbc2ae99c9df5f46353024.tar.xz linux-2f3edfd7e27ad4206acbc2ae99c9df5f46353024.zip | |
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>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/mach-imx/common.h | 2 | ||||
| -rw-r--r-- | arch/arm/mach-imx/hotplug.c | 12 | ||||
| -rw-r--r-- | arch/arm/mach-imx/src.c | 12 |
3 files changed, 26 insertions, 0 deletions
diff --git a/arch/arm/mach-imx/common.h b/arch/arm/mach-imx/common.h index 5a800bfcec5b..5bf4a97ab241 100644 --- a/arch/arm/mach-imx/common.h +++ b/arch/arm/mach-imx/common.h @@ -110,6 +110,8 @@ void tzic_handle_irq(struct pt_regs *); extern void imx_enable_cpu(int cpu, bool enable); extern void imx_set_cpu_jump(int cpu, void *jump_addr); +extern u32 imx_get_cpu_arg(int cpu); +extern void imx_set_cpu_arg(int cpu, u32 arg); extern void v7_cpu_resume(void); extern u32 *pl310_get_save_ptr(void); #ifdef CONFIG_SMP diff --git a/arch/arm/mach-imx/hotplug.c b/arch/arm/mach-imx/hotplug.c index 7bc5fe15dda2..361a253e2b63 100644 --- a/arch/arm/mach-imx/hotplug.c +++ b/arch/arm/mach-imx/hotplug.c @@ -46,11 +46,23 @@ static inline void cpu_enter_lowpower(void) void imx_cpu_die(unsigned int cpu) { cpu_enter_lowpower(); + /* + * We use the cpu jumping argument register to sync with + * imx_cpu_kill() which is running on cpu0 and waiting for + * the register being cleared to kill the cpu. + */ + imx_set_cpu_arg(cpu, ~0); cpu_do_idle(); } int imx_cpu_kill(unsigned int cpu) { + unsigned long timeout = jiffies + msecs_to_jiffies(50); + + while (imx_get_cpu_arg(cpu) == 0) + if (time_after(jiffies, timeout)) + return 0; imx_enable_cpu(cpu, false); + imx_set_cpu_arg(cpu, 0); return 1; } diff --git a/arch/arm/mach-imx/src.c b/arch/arm/mach-imx/src.c index e15f1555c59b..09a742f8c7ab 100644 --- a/arch/arm/mach-imx/src.c +++ b/arch/arm/mach-imx/src.c @@ -43,6 +43,18 @@ void imx_set_cpu_jump(int cpu, void *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; |