[PATCH] arm: exynos: generalize power register address calculation
Chander Kashyap
chander.kashyap at linaro.org
Mon Apr 14 20:58:03 PDT 2014
Hi Tomasz,
Thanks for the review comments,
On 14 April 2014 22:58, Tomasz Figa <tomasz.figa at gmail.com> wrote:
> Hi Chander,
>
> Few more comments inline.
>
>
> On 09.04.2014 13:09, Chander Kashyap wrote:
>>
>> Currently status/configuration power register values are hard-coded for
>> cpu1.
>>
>> Make it generic so that it is useful for SoC's with more than two cpus.
>>
>> Signed-off-by: Chander Kashyap <chander.kashyap at linaro.org>
>> ---
>> changes in v2 : Used existing macros for clusterid and cpuid calculation
>>
>> arch/arm/mach-exynos/hotplug.c | 15 ++++++++++++---
>> arch/arm/mach-exynos/platsmp.c | 20 +++++++++++++++-----
>> arch/arm/mach-exynos/regs-pmu.h | 9 +++++++--
>> 3 files changed, 34 insertions(+), 10 deletions(-)
>>
>> diff --git a/arch/arm/mach-exynos/hotplug.c
>> b/arch/arm/mach-exynos/hotplug.c
>> index 5eead53..eab6121 100644
>> --- a/arch/arm/mach-exynos/hotplug.c
>> +++ b/arch/arm/mach-exynos/hotplug.c
>> @@ -17,6 +17,7 @@
>>
>> #include <asm/cacheflush.h>
>> #include <asm/cp15.h>
>> +#include <asm/cputype.h>
>> #include <asm/smp_plat.h>
>>
>> #include <plat/cpu.h>
>> @@ -92,11 +93,19 @@ static inline void cpu_leave_lowpower(void)
>>
>> static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
>> {
>> + unsigned int mpidr, cpunr, cluster;
>> +
>> + mpidr = cpu_logical_map(cpu);
>> + cpunr = MPIDR_AFFINITY_LEVEL(mpidr, 0);
>> + cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
>> +
>> + /* Maximum possible cpus in a cluster can be 4 */
>> + cpunr += cluster * 4;
>
>
> This could be put in a helper, as it seems to be used both by hotplug and
> platsmp code. Also 4 could be defined as a preprocessor macro.
>
Sounds great. I will modify this.
>
>> for (;;) {
>>
>> - /* make cpu1 to be turned off at next WFI command */
>> - if (cpu == 1)
>> - __raw_writel(0, S5P_ARM_CORE1_CONFIGURATION);
>> + /* make cpu to be turned off at next WFI command */
>> + if (cpu)
>
>
> Do you need this if here at all? I don't think there would be any problem
> with this function called for CPU 0 (which shouldn't happen anyway, without
> CPU 0 hotplug support enabled).
>
Well this is to avoid corner case where someone does cpu-hotplug-out
on cpu0 manually.
>
>> + __raw_writel(0,
>> S5P_ARM_CORE_CONFIGURATION(cpunr));
>>
>> /*
>> * here's the WFI
>> diff --git a/arch/arm/mach-exynos/platsmp.c
>> b/arch/arm/mach-exynos/platsmp.c
>> index 8ea02f6..8d06b2c 100644
>> --- a/arch/arm/mach-exynos/platsmp.c
>> +++ b/arch/arm/mach-exynos/platsmp.c
>> @@ -22,6 +22,7 @@
>> #include <linux/io.h>
>>
>> #include <asm/cacheflush.h>
>> +#include <asm/cputype.h>
>> #include <asm/smp_plat.h>
>> #include <asm/smp_scu.h>
>> #include <asm/firmware.h>
>> @@ -92,6 +93,14 @@ static int exynos_boot_secondary(unsigned int cpu,
>> struct task_struct *idle)
>> {
>> unsigned long timeout;
>> unsigned long phys_cpu = cpu_logical_map(cpu);
>> + unsigned int mpidr, cpunr, cluster;
>> +
>> + mpidr = cpu_logical_map(cpu);
>> + cpunr = MPIDR_AFFINITY_LEVEL(mpidr, 0);
>> + cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
>> +
>> + /* Maximum possible cpus in a cluster can be 4 */
>> + cpunr += cluster * 4;
>
>
> Here basically the same code is used as in hotplug.c, so a helper would be
> nice. (e.g. cpunr = exynos_pmu_cpunr(mpidr)).
Yes,
>
>
>>
>> /*
>> * Set synchronisation state between this boot processor
>> @@ -109,14 +118,15 @@ static int exynos_boot_secondary(unsigned int cpu,
>> struct task_struct *idle)
>> */
>> write_pen_release(phys_cpu);
>>
>> - if (!(__raw_readl(S5P_ARM_CORE1_STATUS) & S5P_CORE_LOCAL_PWR_EN))
>> {
>> + if (!(__raw_readl(S5P_ARM_CORE_STATUS(cpunr))
>> + & S5P_CORE_LOCAL_PWR_EN)) {
>> __raw_writel(S5P_CORE_LOCAL_PWR_EN,
>> - S5P_ARM_CORE1_CONFIGURATION);
>> + S5P_ARM_CORE_CONFIGURATION(cpunr));
>>
>> timeout = 10;
>>
>> - /* wait max 10 ms until cpu1 is on */
>> - while ((__raw_readl(S5P_ARM_CORE1_STATUS)
>> + /* wait max 10 ms until secondary cpu is on */
>> + while ((__raw_readl(S5P_ARM_CORE_STATUS(cpunr))
>> & S5P_CORE_LOCAL_PWR_EN) != S5P_CORE_LOCAL_PWR_EN)
>> {
>> if (timeout-- == 0)
>> break;
>> @@ -125,7 +135,7 @@ static int exynos_boot_secondary(unsigned int cpu,
>> struct task_struct *idle)
>> }
>>
>> if (timeout == 0) {
>> - printk(KERN_ERR "cpu1 power enable failed");
>> + pr_err("cpu%x power enable failed", cpu);
>
>
> Shouldn't %d be used instead? "cpu a" on a 10-core machine would sound
> weird.
Ok.
>
>
>> spin_unlock(&boot_lock);
>> return -ETIMEDOUT;
>> }
>> diff --git a/arch/arm/mach-exynos/regs-pmu.h
>> b/arch/arm/mach-exynos/regs-pmu.h
>> index 7c029ce..16e17e4 100644
>> --- a/arch/arm/mach-exynos/regs-pmu.h
>> +++ b/arch/arm/mach-exynos/regs-pmu.h
>> @@ -104,8 +104,13 @@
>> #define S5P_GPS_LOWPWR S5P_PMUREG(0x139C)
>> #define S5P_GPS_ALIVE_LOWPWR S5P_PMUREG(0x13A0)
>>
>> -#define S5P_ARM_CORE1_CONFIGURATION S5P_PMUREG(0x2080)
>> -#define S5P_ARM_CORE1_STATUS S5P_PMUREG(0x2084)
>> +#define S5P_ARM_CORE0_CONFIGURATION S5P_PMUREG(0x2000)
>> +#define S5P_ARM_CORE0_STATUS S5P_PMUREG(0x2004)
>> +
>> +#define S5P_ARM_CORE_CONFIGURATION(_cpunr) \
>> + (S5P_ARM_CORE0_CONFIGURATION + 0x80 * _cpunr)
>> +#define S5P_ARM_CORE_STATUS(_cpunr) \
>> + (S5P_ARM_CORE0_STATUS + 0x80 * _cpunr)
>
>
> Please wrap _cpunr in parentheses to make sure that passed value doesn't
> affect the order of computations.
ok.
>
> Best regards,
> Tomasz
Thanks again,
--
with warm regards,
Chander Kashyap
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