Re: [PATCH] ARM: EXYNOS: Fix incorrect usage of S5P_ARM_CORE1_* registers

From: Tomasz Figa
Date: Tue Jun 18 2013 - 13:45:42 EST


Ccing Arnd and Olof, because I forgot to add them to git send-email...

Sorry for the noise.

On Tuesday 18 of June 2013 17:26:31 Tomasz Figa wrote:
> S5P_ARM_CORE1_* registers affect only core 1. To control further cores
> properly another registers must be used.
>
> This patch replaces S5P_ARM_CORE1_* register definitions with
> S5P_ARM_CORE_*(x) macro which return addresses of registers for
> specified core.
>
> This fixes CPU hotplug on quad core Exynos SoCs on which currently
> offlining CPUs 2 or 3 caused CPU 1 to be turned off.

Obviously this doesn't happen currently because of the if (cpu == 1), but
if logical cpu1 turned out not to be physical cpu1, then it would crash.

Best regards,
Tomasz

> In addition,
> bring-up of CPU 2 and 3 is fixed on boards where bootloader powers off
> secondary cores by default.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Tomasz Figa <t.figa@xxxxxxxxxxx>
> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> ---
> arch/arm/mach-exynos/hotplug.c | 9 +++++----
> arch/arm/mach-exynos/include/mach/regs-pmu.h | 10 +++++++---
> arch/arm/mach-exynos/platsmp.c | 9 +++++----
> 3 files changed, 17 insertions(+), 11 deletions(-)
>
> diff --git a/arch/arm/mach-exynos/hotplug.c
> b/arch/arm/mach-exynos/hotplug.c index af90cfa..c089943 100644
> --- a/arch/arm/mach-exynos/hotplug.c
> +++ b/arch/arm/mach-exynos/hotplug.c
> @@ -93,10 +93,11 @@ static inline void cpu_leave_lowpower(void)
> static inline void platform_do_lowpower(unsigned int cpu, int
> *spurious) {
> for (;;) {
> + void __iomem *reg_base;
> + unsigned int phys_cpu = cpu_logical_map(cpu);
>
> - /* make cpu1 to be turned off at next WFI command */
> - if (cpu == 1)
> - __raw_writel(0, S5P_ARM_CORE1_CONFIGURATION);
> + reg_base = S5P_ARM_CORE_CONFIGURATION(phys_cpu);
> + __raw_writel(0, reg_base);
>
> /*
> * here's the WFI
> @@ -106,7 +107,7 @@ static inline void platform_do_lowpower(unsigned int
> cpu, int *spurious)
> : "memory", "cc");
>
> - if (pen_release == cpu_logical_map(cpu)) {
> + if (pen_release == phys_cpu) {
> /*
> * OK, proper wakeup, we're done
> */
> diff --git a/arch/arm/mach-exynos/include/mach/regs-pmu.h
> b/arch/arm/mach-exynos/include/mach/regs-pmu.h index 57344b7..cf40b86
> 100644
> --- a/arch/arm/mach-exynos/include/mach/regs-pmu.h
> +++ b/arch/arm/mach-exynos/include/mach/regs-pmu.h
> @@ -125,10 +125,14 @@
> #define S5P_GPS_ALIVE_LOWPWR S5P_PMUREG(0x13A0)
>
> #define S5P_ARM_CORE0_CONFIGURATION S5P_PMUREG(0x2000)
> +#define S5P_ARM_CORE0_STATUS S5P_PMUREG(0x2004)
> #define S5P_ARM_CORE0_OPTION S5P_PMUREG(0x2008)
> -#define S5P_ARM_CORE1_CONFIGURATION S5P_PMUREG(0x2080)
> -#define S5P_ARM_CORE1_STATUS S5P_PMUREG(0x2084)
> -#define S5P_ARM_CORE1_OPTION S5P_PMUREG(0x2088)
> +#define S5P_ARM_CORE_CONFIGURATION(_nr) \
> + (S5P_ARM_CORE0_CONFIGURATION + ((_nr) * 0x80))
> +#define S5P_ARM_CORE_STATUS(_nr) \
> + (S5P_ARM_CORE0_STATUS + ((_nr) * 0x80))
> +#define S5P_ARM_CORE_OPTION(_nr) \
> + (S5P_ARM_CORE0_OPTION + ((_nr) * 0x80))
>
> #define S5P_ARM_COMMON_OPTION S5P_PMUREG(0x2408)
> #define S5P_TOP_PWR_OPTION S5P_PMUREG(0x2C48)
> diff --git a/arch/arm/mach-exynos/platsmp.c
> b/arch/arm/mach-exynos/platsmp.c index d9c6d0a..2cbabc8 100644
> --- a/arch/arm/mach-exynos/platsmp.c
> +++ b/arch/arm/mach-exynos/platsmp.c
> @@ -109,14 +109,15 @@ static int __cpuinit
> exynos_boot_secondary(unsigned int cpu, struct task_struct */
> write_pen_release(phys_cpu);
>
> - if (!(__raw_readl(S5P_ARM_CORE1_STATUS) & S5P_CORE_LOCAL_PWR_EN))
{
> + if (!(__raw_readl(S5P_ARM_CORE_STATUS(phys_cpu))
> + & S5P_CORE_LOCAL_PWR_EN)) {
> __raw_writel(S5P_CORE_LOCAL_PWR_EN,
> - S5P_ARM_CORE1_CONFIGURATION);
> + S5P_ARM_CORE_CONFIGURATION(phys_cpu));
>
> timeout = 10;
>
> /* wait max 10 ms until cpu1 is on */
> - while ((__raw_readl(S5P_ARM_CORE1_STATUS)
> + while ((__raw_readl(S5P_ARM_CORE_STATUS(phys_cpu))
> & S5P_CORE_LOCAL_PWR_EN) != S5P_CORE_LOCAL_PWR_EN)
{
> if (timeout-- == 0)
> break;
> @@ -125,7 +126,7 @@ static int __cpuinit exynos_boot_secondary(unsigned
> int cpu, struct task_struct }
>
> if (timeout == 0) {
> - printk(KERN_ERR "cpu1 power enable failed");
> + printk(KERN_ERR "cpu%u power enable failed", cpu);
> spin_unlock(&boot_lock);
> return -ETIMEDOUT;
> }
--
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