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

[Chander Kashyap <chander.kashyap@linaro.org>]

On 18 June 2013 23:29, Kukjin Kim <kgene.kim@samsung.com> wrote:
> On 06/19/13 02:45, Tomasz Figa wrote:
>>
>> 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
>
>
> Yes, not happened...and just note exynos5440 doesn't support hotplug :) so
> this is available on exynos4412 and added 5420.
>
>
>> 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.
>>>
> I need to test on board about above...
>
>>> Cc: stable@vger.kernel.org
>>> Signed-off-by: Tomasz Figa<t.figa@samsung.com>
>>> Signed-off-by: Kyungmin Park<kyungmin.park@samsung.com>
>>> ---
>>>   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);
Tomasz,
This will break for non-zero, MPIDR value.  Say if MPIDR is 1 then for
cpu0 phys_cpu value will be 0x100,
and address calculation will be   (S5P_ARM_CORE0_CONFIGURATION +
((0x101) * 0x80)), which is wrong.
>>> +               __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))
Ditto
>>>                         &  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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--
with warm regards,
Chander Kashyap