diff mbox

[v7] ARM: EXYNOS: Use MCPM call-backs to support S2R on Exynos5420

Message ID 1404503133-19760-1-git-send-email-a.kesavan@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Abhilash Kesavan July 4, 2014, 7:45 p.m. UTC
Use the MCPM layer to handle core suspend/resume on Exynos5420.
Also, restore the entry address setup code post-resume.

Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
---
Changes in v2:
	- Made use of the MCPM suspend/powered_up call-backs
Changes in v3:
	- Used the residency value to indicate the entered state
Changes in v4:
	- Checked if MCPM has been enabled to prevent build error
Changes in v5:
	- Removed the MCPM flags and just used a local flag to
	indicate that we are suspending.
Changes in v6:
	- Read the SYS_PWR_REG value to decide if we are suspending
	the system.
	- Restore the SYS_PWR_REG value post-resume.
	- Modified the comments to reflect the first change.
Changes in v7:
	- Add the suspend check in exynos_cpu_power_down() rather
	than the MCPM back-end.
	- Clean-up unnecessary changes related to earlier versions.

This has been tested both on an SMDK5420 and Peach Pit Chromebook on
next-20140704. Nicolas' boot cluster CCI enablement patches are in
linux-next now.

Here are the dependencies (some of these patches did not apply cleanly):
1) Cleanup patches for mach-exynos
http://comments.gmane.org/gmane.linux.kernel.samsung-soc/33772

2) PMU cleanup and refactoring for using DT
https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg671625.html

3) Exynos5420 PMU/S2R Series
http://comments.gmane.org/gmane.linux.kernel.samsung-soc/33898

4) Exynos5420 CPUIdle Series which populates MCPM suspend/powered_up
call-backs.
www.gossamer-threads.com/lists/linux/kernel/1945347
https://patchwork.kernel.org/patch/4357461/

5) Exynos5420 MCPM cluster power down support
http://www.spinics.net/lists/arm-kernel/msg339988.html

6) TPM reset mask patch
http://www.spinics.net/lists/arm-kernel/msg341884.html
 
 arch/arm/mach-exynos/mcpm-exynos.c | 32 +++++++++++++++-------
 arch/arm/mach-exynos/pm.c          | 54 ++++++++++++++++++++++++++++++++++++--
 2 files changed, 74 insertions(+), 12 deletions(-)

Comments

Nicolas Pitre July 4, 2014, 9 p.m. UTC | #1
On Sat, 5 Jul 2014, Abhilash Kesavan wrote:

> Use the MCPM layer to handle core suspend/resume on Exynos5420.
> Also, restore the entry address setup code post-resume.
> 
> Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>

Acked-by: Nicolas Pitre <nico@linaro.org>


> ---
> Changes in v2:
> 	- Made use of the MCPM suspend/powered_up call-backs
> Changes in v3:
> 	- Used the residency value to indicate the entered state
> Changes in v4:
> 	- Checked if MCPM has been enabled to prevent build error
> Changes in v5:
> 	- Removed the MCPM flags and just used a local flag to
> 	indicate that we are suspending.
> Changes in v6:
> 	- Read the SYS_PWR_REG value to decide if we are suspending
> 	the system.
> 	- Restore the SYS_PWR_REG value post-resume.
> 	- Modified the comments to reflect the first change.
> Changes in v7:
> 	- Add the suspend check in exynos_cpu_power_down() rather
> 	than the MCPM back-end.
> 	- Clean-up unnecessary changes related to earlier versions.
> 
> This has been tested both on an SMDK5420 and Peach Pit Chromebook on
> next-20140704. Nicolas' boot cluster CCI enablement patches are in
> linux-next now.
> 
> Here are the dependencies (some of these patches did not apply cleanly):
> 1) Cleanup patches for mach-exynos
> http://comments.gmane.org/gmane.linux.kernel.samsung-soc/33772
> 
> 2) PMU cleanup and refactoring for using DT
> https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg671625.html
> 
> 3) Exynos5420 PMU/S2R Series
> http://comments.gmane.org/gmane.linux.kernel.samsung-soc/33898
> 
> 4) Exynos5420 CPUIdle Series which populates MCPM suspend/powered_up
> call-backs.
> www.gossamer-threads.com/lists/linux/kernel/1945347
> https://patchwork.kernel.org/patch/4357461/
> 
> 5) Exynos5420 MCPM cluster power down support
> http://www.spinics.net/lists/arm-kernel/msg339988.html
> 
> 6) TPM reset mask patch
> http://www.spinics.net/lists/arm-kernel/msg341884.html
>  
>  arch/arm/mach-exynos/mcpm-exynos.c | 32 +++++++++++++++-------
>  arch/arm/mach-exynos/pm.c          | 54 ++++++++++++++++++++++++++++++++++++--
>  2 files changed, 74 insertions(+), 12 deletions(-)
> 
> diff --git a/arch/arm/mach-exynos/mcpm-exynos.c b/arch/arm/mach-exynos/mcpm-exynos.c
> index 2dd51cc..74ad772 100644
> --- a/arch/arm/mach-exynos/mcpm-exynos.c
> +++ b/arch/arm/mach-exynos/mcpm-exynos.c
> @@ -15,6 +15,7 @@
>  #include <linux/delay.h>
>  #include <linux/io.h>
>  #include <linux/of_address.h>
> +#include <linux/syscore_ops.h>
>  
>  #include <asm/cputype.h>
>  #include <asm/cp15.h>
> @@ -30,6 +31,8 @@
>  #define EXYNOS5420_USE_ARM_CORE_DOWN_STATE	BIT(29)
>  #define EXYNOS5420_USE_L2_COMMON_UP_STATE	BIT(30)
>  
> +static void __iomem *ns_sram_base_addr;
> +
>  /*
>   * The common v7_exit_coherency_flush API could not be used because of the
>   * Erratum 799270 workaround. This macro is the same as the common one (in
> @@ -319,10 +322,26 @@ static const struct of_device_id exynos_dt_mcpm_match[] = {
>  	{},
>  };
>  
> +static void exynos_mcpm_setup_entry_point(void)
> +{
> +	/*
> +	 * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
> +	 * as part of secondary_cpu_start().  Let's redirect it to the
> +	 * mcpm_entry_point(). This is done during both secondary boot-up as
> +	 * well as system resume.
> +	 */
> +	__raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
> +	__raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
> +	__raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
> +}
> +
> +static struct syscore_ops exynos_mcpm_syscore_ops = {
> +	.resume	= exynos_mcpm_setup_entry_point,
> +};
> +
>  static int __init exynos_mcpm_init(void)
>  {
>  	struct device_node *node;
> -	void __iomem *ns_sram_base_addr;
>  	unsigned int value, i;
>  	int ret;
>  
> @@ -389,16 +408,9 @@ static int __init exynos_mcpm_init(void)
>  		__raw_writel(value, pmu_base_addr + EXYNOS_COMMON_OPTION(i));
>  	}
>  
> -	/*
> -	 * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
> -	 * as part of secondary_cpu_start().  Let's redirect it to the
> -	 * mcpm_entry_point().
> -	 */
> -	__raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
> -	__raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
> -	__raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
> +	exynos_mcpm_setup_entry_point();
>  
> -	iounmap(ns_sram_base_addr);
> +	register_syscore_ops(&exynos_mcpm_syscore_ops);
>  
>  	return ret;
>  }
> diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
> index 69cf678..e2ba1e5 100644
> --- a/arch/arm/mach-exynos/pm.c
> +++ b/arch/arm/mach-exynos/pm.c
> @@ -24,6 +24,7 @@
>  
>  #include <asm/cacheflush.h>
>  #include <asm/hardware/cache-l2x0.h>
> +#include <asm/mcpm.h>
>  #include <asm/smp_scu.h>
>  #include <asm/suspend.h>
>  
> @@ -123,6 +124,17 @@ static int exynos_irq_set_wake(struct irq_data *data, unsigned int state)
>   */
>  void exynos_cpu_power_down(int cpu)
>  {
> +	if (soc_is_exynos5420() && cpu == 0) {
> +		/*
> +		 * Bypass power down for CPU0 during suspend. Check for
> +		 * the SYS_PWR_REG value to decide if we are suspending
> +		 * the system.
> +		 */
> +		int val = __raw_readl(pmu_base_addr +
> +				EXYNOS5_ARM_CORE0_SYS_PWR_REG);
> +		if (!(val & S5P_CORE_LOCAL_PWR_EN))
> +			return;
> +	}
>  	pmu_raw_writel(0, EXYNOS_ARM_CORE_CONFIGURATION(cpu));
>  }
>  
> @@ -318,7 +330,10 @@ static void exynos_pm_prepare(void)
>  
>  	/* ensure at least INFORM0 has the resume address */
>  
> -	pmu_raw_writel(virt_to_phys(exynos_cpu_resume), S5P_INFORM0);
> +	if (soc_is_exynos5420() && IS_ENABLED(CONFIG_MCPM))
> +		pmu_raw_writel(virt_to_phys(mcpm_entry_point), S5P_INFORM0);
> +	else
> +		pmu_raw_writel(virt_to_phys(exynos_cpu_resume), S5P_INFORM0);
>  
>  	if (soc_is_exynos5420()) {
>  		tmp = __raw_readl(pmu_base_addr + EXYNOS5_ARM_L2_OPTION);
> @@ -408,6 +423,12 @@ static void exynos_pm_resume(void)
>  	unsigned int tmp;
>  
>  	if (soc_is_exynos5420()) {
> +		/* Restore the CPU0 low power state register */
> +		tmp = __raw_readl(pmu_base_addr +
> +			EXYNOS5_ARM_CORE0_SYS_PWR_REG);
> +		pmu_raw_writel(tmp | S5P_CORE_LOCAL_PWR_EN,
> +			EXYNOS5_ARM_CORE0_SYS_PWR_REG);
> +
>  		/* Restore the sysram cpu state register */
>  		__raw_writel(exynos5420_cpu_state,
>  		sysram_base_addr + EXYNOS5420_CPU_STATE);
> @@ -490,6 +511,28 @@ static struct syscore_ops exynos_pm_syscore_ops = {
>  	.resume		= exynos_pm_resume,
>  };
>  
> +static int notrace exynos_mcpm_cpu_suspend(unsigned long arg)
> +{
> +	/* MCPM works with HW CPU identifiers */
> +	unsigned int mpidr = read_cpuid_mpidr();
> +	unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
> +	unsigned int cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
> +
> +	__raw_writel(0x0, sysram_base_addr + EXYNOS5420_CPU_STATE);
> +
> +	mcpm_set_entry_vector(cpu, cluster, exynos_cpu_resume);
> +
> +	/*
> +	 * Residency value passed to mcpm_cpu_suspend back-end
> +	 * has to be given clear semantics. Set to 0 as a
> +	 * temporary value.
> +	 */
> +	mcpm_cpu_suspend(0);
> +
> +	/* return value != 0 means failure */
> +	return 1;
> +}
> +
>  /*
>   * Suspend Ops
>   */
> @@ -517,10 +560,17 @@ static int exynos_suspend_enter(suspend_state_t state)
>  	flush_cache_all();
>  	s3c_pm_check_store();
>  
> -	ret = cpu_suspend(0, exynos_cpu_suspend);
> +	/* Use the MCPM layer to suspend 5420 which is a multi-cluster SoC */
> +	if (soc_is_exynos5420() && IS_ENABLED(CONFIG_MCPM))
> +		ret = cpu_suspend(0, exynos_mcpm_cpu_suspend);
> +	else
> +		ret = cpu_suspend(0, exynos_cpu_suspend);
>  	if (ret)
>  		return ret;
>  
> +	if (soc_is_exynos5420() && IS_ENABLED(CONFIG_MCPM))
> +		mcpm_cpu_powered_up();
> +
>  	s3c_pm_restore_uarts();
>  
>  	S3C_PMDBG("%s: wakeup stat: %08x\n", __func__,
> -- 
> 2.0.0
> 
> 
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Abhilash Kesavan July 4, 2014, 9:21 p.m. UTC | #2
On Sat, Jul 5, 2014 at 2:30 AM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote:
> On Sat, 5 Jul 2014, Abhilash Kesavan wrote:
>
>> Use the MCPM layer to handle core suspend/resume on Exynos5420.
>> Also, restore the entry address setup code post-resume.
>>
>> Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
>
> Acked-by: Nicolas Pitre <nico@linaro.org>
This is one of the last missing bits for exynos MCPM. Thanks for your
patient reviews of all the exynos mcpm back-end patches.

Regards,
Abhilash
>
>
>> ---
>> Changes in v2:
>>       - Made use of the MCPM suspend/powered_up call-backs
>> Changes in v3:
>>       - Used the residency value to indicate the entered state
>> Changes in v4:
>>       - Checked if MCPM has been enabled to prevent build error
>> Changes in v5:
>>       - Removed the MCPM flags and just used a local flag to
>>       indicate that we are suspending.
>> Changes in v6:
>>       - Read the SYS_PWR_REG value to decide if we are suspending
>>       the system.
>>       - Restore the SYS_PWR_REG value post-resume.
>>       - Modified the comments to reflect the first change.
>> Changes in v7:
>>       - Add the suspend check in exynos_cpu_power_down() rather
>>       than the MCPM back-end.
>>       - Clean-up unnecessary changes related to earlier versions.
>>
>> This has been tested both on an SMDK5420 and Peach Pit Chromebook on
>> next-20140704. Nicolas' boot cluster CCI enablement patches are in
>> linux-next now.
>>
>> Here are the dependencies (some of these patches did not apply cleanly):
>> 1) Cleanup patches for mach-exynos
>> http://comments.gmane.org/gmane.linux.kernel.samsung-soc/33772
>>
>> 2) PMU cleanup and refactoring for using DT
>> https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg671625.html
>>
>> 3) Exynos5420 PMU/S2R Series
>> http://comments.gmane.org/gmane.linux.kernel.samsung-soc/33898
>>
>> 4) Exynos5420 CPUIdle Series which populates MCPM suspend/powered_up
>> call-backs.
>> www.gossamer-threads.com/lists/linux/kernel/1945347
>> https://patchwork.kernel.org/patch/4357461/
>>
>> 5) Exynos5420 MCPM cluster power down support
>> http://www.spinics.net/lists/arm-kernel/msg339988.html
>>
>> 6) TPM reset mask patch
>> http://www.spinics.net/lists/arm-kernel/msg341884.html
>>
>>  arch/arm/mach-exynos/mcpm-exynos.c | 32 +++++++++++++++-------
>>  arch/arm/mach-exynos/pm.c          | 54 ++++++++++++++++++++++++++++++++++++--
>>  2 files changed, 74 insertions(+), 12 deletions(-)
>>
>> diff --git a/arch/arm/mach-exynos/mcpm-exynos.c b/arch/arm/mach-exynos/mcpm-exynos.c
>> index 2dd51cc..74ad772 100644
>> --- a/arch/arm/mach-exynos/mcpm-exynos.c
>> +++ b/arch/arm/mach-exynos/mcpm-exynos.c
>> @@ -15,6 +15,7 @@
>>  #include <linux/delay.h>
>>  #include <linux/io.h>
>>  #include <linux/of_address.h>
>> +#include <linux/syscore_ops.h>
>>
>>  #include <asm/cputype.h>
>>  #include <asm/cp15.h>
>> @@ -30,6 +31,8 @@
>>  #define EXYNOS5420_USE_ARM_CORE_DOWN_STATE   BIT(29)
>>  #define EXYNOS5420_USE_L2_COMMON_UP_STATE    BIT(30)
>>
>> +static void __iomem *ns_sram_base_addr;
>> +
>>  /*
>>   * The common v7_exit_coherency_flush API could not be used because of the
>>   * Erratum 799270 workaround. This macro is the same as the common one (in
>> @@ -319,10 +322,26 @@ static const struct of_device_id exynos_dt_mcpm_match[] = {
>>       {},
>>  };
>>
>> +static void exynos_mcpm_setup_entry_point(void)
>> +{
>> +     /*
>> +      * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
>> +      * as part of secondary_cpu_start().  Let's redirect it to the
>> +      * mcpm_entry_point(). This is done during both secondary boot-up as
>> +      * well as system resume.
>> +      */
>> +     __raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
>> +     __raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
>> +     __raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
>> +}
>> +
>> +static struct syscore_ops exynos_mcpm_syscore_ops = {
>> +     .resume = exynos_mcpm_setup_entry_point,
>> +};
>> +
>>  static int __init exynos_mcpm_init(void)
>>  {
>>       struct device_node *node;
>> -     void __iomem *ns_sram_base_addr;
>>       unsigned int value, i;
>>       int ret;
>>
>> @@ -389,16 +408,9 @@ static int __init exynos_mcpm_init(void)
>>               __raw_writel(value, pmu_base_addr + EXYNOS_COMMON_OPTION(i));
>>       }
>>
>> -     /*
>> -      * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
>> -      * as part of secondary_cpu_start().  Let's redirect it to the
>> -      * mcpm_entry_point().
>> -      */
>> -     __raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
>> -     __raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
>> -     __raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
>> +     exynos_mcpm_setup_entry_point();
>>
>> -     iounmap(ns_sram_base_addr);
>> +     register_syscore_ops(&exynos_mcpm_syscore_ops);
>>
>>       return ret;
>>  }
>> diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
>> index 69cf678..e2ba1e5 100644
>> --- a/arch/arm/mach-exynos/pm.c
>> +++ b/arch/arm/mach-exynos/pm.c
>> @@ -24,6 +24,7 @@
>>
>>  #include <asm/cacheflush.h>
>>  #include <asm/hardware/cache-l2x0.h>
>> +#include <asm/mcpm.h>
>>  #include <asm/smp_scu.h>
>>  #include <asm/suspend.h>
>>
>> @@ -123,6 +124,17 @@ static int exynos_irq_set_wake(struct irq_data *data, unsigned int state)
>>   */
>>  void exynos_cpu_power_down(int cpu)
>>  {
>> +     if (soc_is_exynos5420() && cpu == 0) {
>> +             /*
>> +              * Bypass power down for CPU0 during suspend. Check for
>> +              * the SYS_PWR_REG value to decide if we are suspending
>> +              * the system.
>> +              */
>> +             int val = __raw_readl(pmu_base_addr +
>> +                             EXYNOS5_ARM_CORE0_SYS_PWR_REG);
>> +             if (!(val & S5P_CORE_LOCAL_PWR_EN))
>> +                     return;
>> +     }
>>       pmu_raw_writel(0, EXYNOS_ARM_CORE_CONFIGURATION(cpu));
>>  }
>>
>> @@ -318,7 +330,10 @@ static void exynos_pm_prepare(void)
>>
>>       /* ensure at least INFORM0 has the resume address */
>>
>> -     pmu_raw_writel(virt_to_phys(exynos_cpu_resume), S5P_INFORM0);
>> +     if (soc_is_exynos5420() && IS_ENABLED(CONFIG_MCPM))
>> +             pmu_raw_writel(virt_to_phys(mcpm_entry_point), S5P_INFORM0);
>> +     else
>> +             pmu_raw_writel(virt_to_phys(exynos_cpu_resume), S5P_INFORM0);
>>
>>       if (soc_is_exynos5420()) {
>>               tmp = __raw_readl(pmu_base_addr + EXYNOS5_ARM_L2_OPTION);
>> @@ -408,6 +423,12 @@ static void exynos_pm_resume(void)
>>       unsigned int tmp;
>>
>>       if (soc_is_exynos5420()) {
>> +             /* Restore the CPU0 low power state register */
>> +             tmp = __raw_readl(pmu_base_addr +
>> +                     EXYNOS5_ARM_CORE0_SYS_PWR_REG);
>> +             pmu_raw_writel(tmp | S5P_CORE_LOCAL_PWR_EN,
>> +                     EXYNOS5_ARM_CORE0_SYS_PWR_REG);
>> +
>>               /* Restore the sysram cpu state register */
>>               __raw_writel(exynos5420_cpu_state,
>>               sysram_base_addr + EXYNOS5420_CPU_STATE);
>> @@ -490,6 +511,28 @@ static struct syscore_ops exynos_pm_syscore_ops = {
>>       .resume         = exynos_pm_resume,
>>  };
>>
>> +static int notrace exynos_mcpm_cpu_suspend(unsigned long arg)
>> +{
>> +     /* MCPM works with HW CPU identifiers */
>> +     unsigned int mpidr = read_cpuid_mpidr();
>> +     unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
>> +     unsigned int cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
>> +
>> +     __raw_writel(0x0, sysram_base_addr + EXYNOS5420_CPU_STATE);
>> +
>> +     mcpm_set_entry_vector(cpu, cluster, exynos_cpu_resume);
>> +
>> +     /*
>> +      * Residency value passed to mcpm_cpu_suspend back-end
>> +      * has to be given clear semantics. Set to 0 as a
>> +      * temporary value.
>> +      */
>> +     mcpm_cpu_suspend(0);
>> +
>> +     /* return value != 0 means failure */
>> +     return 1;
>> +}
>> +
>>  /*
>>   * Suspend Ops
>>   */
>> @@ -517,10 +560,17 @@ static int exynos_suspend_enter(suspend_state_t state)
>>       flush_cache_all();
>>       s3c_pm_check_store();
>>
>> -     ret = cpu_suspend(0, exynos_cpu_suspend);
>> +     /* Use the MCPM layer to suspend 5420 which is a multi-cluster SoC */
>> +     if (soc_is_exynos5420() && IS_ENABLED(CONFIG_MCPM))
>> +             ret = cpu_suspend(0, exynos_mcpm_cpu_suspend);
>> +     else
>> +             ret = cpu_suspend(0, exynos_cpu_suspend);
>>       if (ret)
>>               return ret;
>>
>> +     if (soc_is_exynos5420() && IS_ENABLED(CONFIG_MCPM))
>> +             mcpm_cpu_powered_up();
>> +
>>       s3c_pm_restore_uarts();
>>
>>       S3C_PMDBG("%s: wakeup stat: %08x\n", __func__,
>> --
>> 2.0.0
>>
>>
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Lorenzo Pieralisi July 8, 2014, 10:53 a.m. UTC | #3
On Fri, Jul 04, 2014 at 10:21:56PM +0100, Abhilash Kesavan wrote:
> On Sat, Jul 5, 2014 at 2:30 AM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote:
> > On Sat, 5 Jul 2014, Abhilash Kesavan wrote:
> >
> >> Use the MCPM layer to handle core suspend/resume on Exynos5420.
> >> Also, restore the entry address setup code post-resume.
> >>
> >> Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
> >
> > Acked-by: Nicolas Pitre <nico@linaro.org>
> This is one of the last missing bits for exynos MCPM. Thanks for your
> patient reviews of all the exynos mcpm back-end patches.

Sorry for the delay in getting back to you.

You still need to handle the residency parameter in the MCPM suspend call
properly to differentiate between core gating and cluster gating.

CPUidle might want to request a state that allows for core gating
residency but not cluster gating one, in that case the last man
standing must not shutdown the cluster.

This must be handled in the power down function, and it can be done
in a separate patch since it is an optimization. Current MCPM interface has
all it is needed to handle this properly, and I am keen on patching the
CPUidle bL driver to pass the actual residency instead of hardcoding it
to 0 (ie on TC2 it was not needed, no core gating).

Lorenzo

> 
> Regards,
> Abhilash
> >
> >
> >> ---
> >> Changes in v2:
> >>       - Made use of the MCPM suspend/powered_up call-backs
> >> Changes in v3:
> >>       - Used the residency value to indicate the entered state
> >> Changes in v4:
> >>       - Checked if MCPM has been enabled to prevent build error
> >> Changes in v5:
> >>       - Removed the MCPM flags and just used a local flag to
> >>       indicate that we are suspending.
> >> Changes in v6:
> >>       - Read the SYS_PWR_REG value to decide if we are suspending
> >>       the system.
> >>       - Restore the SYS_PWR_REG value post-resume.
> >>       - Modified the comments to reflect the first change.
> >> Changes in v7:
> >>       - Add the suspend check in exynos_cpu_power_down() rather
> >>       than the MCPM back-end.
> >>       - Clean-up unnecessary changes related to earlier versions.
> >>
> >> This has been tested both on an SMDK5420 and Peach Pit Chromebook on
> >> next-20140704. Nicolas' boot cluster CCI enablement patches are in
> >> linux-next now.
> >>
> >> Here are the dependencies (some of these patches did not apply cleanly):
> >> 1) Cleanup patches for mach-exynos
> >> http://comments.gmane.org/gmane.linux.kernel.samsung-soc/33772
> >>
> >> 2) PMU cleanup and refactoring for using DT
> >> https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg671625.html
> >>
> >> 3) Exynos5420 PMU/S2R Series
> >> http://comments.gmane.org/gmane.linux.kernel.samsung-soc/33898
> >>
> >> 4) Exynos5420 CPUIdle Series which populates MCPM suspend/powered_up
> >> call-backs.
> >> www.gossamer-threads.com/lists/linux/kernel/1945347
> >> https://patchwork.kernel.org/patch/4357461/
> >>
> >> 5) Exynos5420 MCPM cluster power down support
> >> http://www.spinics.net/lists/arm-kernel/msg339988.html
> >>
> >> 6) TPM reset mask patch
> >> http://www.spinics.net/lists/arm-kernel/msg341884.html
> >>
> >>  arch/arm/mach-exynos/mcpm-exynos.c | 32 +++++++++++++++-------
> >>  arch/arm/mach-exynos/pm.c          | 54 ++++++++++++++++++++++++++++++++++++--
> >>  2 files changed, 74 insertions(+), 12 deletions(-)
> >>
> >> diff --git a/arch/arm/mach-exynos/mcpm-exynos.c b/arch/arm/mach-exynos/mcpm-exynos.c
> >> index 2dd51cc..74ad772 100644
> >> --- a/arch/arm/mach-exynos/mcpm-exynos.c
> >> +++ b/arch/arm/mach-exynos/mcpm-exynos.c
> >> @@ -15,6 +15,7 @@
> >>  #include <linux/delay.h>
> >>  #include <linux/io.h>
> >>  #include <linux/of_address.h>
> >> +#include <linux/syscore_ops.h>
> >>
> >>  #include <asm/cputype.h>
> >>  #include <asm/cp15.h>
> >> @@ -30,6 +31,8 @@
> >>  #define EXYNOS5420_USE_ARM_CORE_DOWN_STATE   BIT(29)
> >>  #define EXYNOS5420_USE_L2_COMMON_UP_STATE    BIT(30)
> >>
> >> +static void __iomem *ns_sram_base_addr;
> >> +
> >>  /*
> >>   * The common v7_exit_coherency_flush API could not be used because of the
> >>   * Erratum 799270 workaround. This macro is the same as the common one (in
> >> @@ -319,10 +322,26 @@ static const struct of_device_id exynos_dt_mcpm_match[] = {
> >>       {},
> >>  };
> >>
> >> +static void exynos_mcpm_setup_entry_point(void)
> >> +{
> >> +     /*
> >> +      * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
> >> +      * as part of secondary_cpu_start().  Let's redirect it to the
> >> +      * mcpm_entry_point(). This is done during both secondary boot-up as
> >> +      * well as system resume.
> >> +      */
> >> +     __raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
> >> +     __raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
> >> +     __raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
> >> +}
> >> +
> >> +static struct syscore_ops exynos_mcpm_syscore_ops = {
> >> +     .resume = exynos_mcpm_setup_entry_point,
> >> +};
> >> +
> >>  static int __init exynos_mcpm_init(void)
> >>  {
> >>       struct device_node *node;
> >> -     void __iomem *ns_sram_base_addr;
> >>       unsigned int value, i;
> >>       int ret;
> >>
> >> @@ -389,16 +408,9 @@ static int __init exynos_mcpm_init(void)
> >>               __raw_writel(value, pmu_base_addr + EXYNOS_COMMON_OPTION(i));
> >>       }
> >>
> >> -     /*
> >> -      * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
> >> -      * as part of secondary_cpu_start().  Let's redirect it to the
> >> -      * mcpm_entry_point().
> >> -      */
> >> -     __raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
> >> -     __raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
> >> -     __raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
> >> +     exynos_mcpm_setup_entry_point();
> >>
> >> -     iounmap(ns_sram_base_addr);
> >> +     register_syscore_ops(&exynos_mcpm_syscore_ops);
> >>
> >>       return ret;
> >>  }
> >> diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
> >> index 69cf678..e2ba1e5 100644
> >> --- a/arch/arm/mach-exynos/pm.c
> >> +++ b/arch/arm/mach-exynos/pm.c
> >> @@ -24,6 +24,7 @@
> >>
> >>  #include <asm/cacheflush.h>
> >>  #include <asm/hardware/cache-l2x0.h>
> >> +#include <asm/mcpm.h>
> >>  #include <asm/smp_scu.h>
> >>  #include <asm/suspend.h>
> >>
> >> @@ -123,6 +124,17 @@ static int exynos_irq_set_wake(struct irq_data *data, unsigned int state)
> >>   */
> >>  void exynos_cpu_power_down(int cpu)
> >>  {
> >> +     if (soc_is_exynos5420() && cpu == 0) {
> >> +             /*
> >> +              * Bypass power down for CPU0 during suspend. Check for
> >> +              * the SYS_PWR_REG value to decide if we are suspending
> >> +              * the system.
> >> +              */
> >> +             int val = __raw_readl(pmu_base_addr +
> >> +                             EXYNOS5_ARM_CORE0_SYS_PWR_REG);
> >> +             if (!(val & S5P_CORE_LOCAL_PWR_EN))
> >> +                     return;
> >> +     }
> >>       pmu_raw_writel(0, EXYNOS_ARM_CORE_CONFIGURATION(cpu));
> >>  }
> >>
> >> @@ -318,7 +330,10 @@ static void exynos_pm_prepare(void)
> >>
> >>       /* ensure at least INFORM0 has the resume address */
> >>
> >> -     pmu_raw_writel(virt_to_phys(exynos_cpu_resume), S5P_INFORM0);
> >> +     if (soc_is_exynos5420() && IS_ENABLED(CONFIG_MCPM))
> >> +             pmu_raw_writel(virt_to_phys(mcpm_entry_point), S5P_INFORM0);
> >> +     else
> >> +             pmu_raw_writel(virt_to_phys(exynos_cpu_resume), S5P_INFORM0);
> >>
> >>       if (soc_is_exynos5420()) {
> >>               tmp = __raw_readl(pmu_base_addr + EXYNOS5_ARM_L2_OPTION);
> >> @@ -408,6 +423,12 @@ static void exynos_pm_resume(void)
> >>       unsigned int tmp;
> >>
> >>       if (soc_is_exynos5420()) {
> >> +             /* Restore the CPU0 low power state register */
> >> +             tmp = __raw_readl(pmu_base_addr +
> >> +                     EXYNOS5_ARM_CORE0_SYS_PWR_REG);
> >> +             pmu_raw_writel(tmp | S5P_CORE_LOCAL_PWR_EN,
> >> +                     EXYNOS5_ARM_CORE0_SYS_PWR_REG);
> >> +
> >>               /* Restore the sysram cpu state register */
> >>               __raw_writel(exynos5420_cpu_state,
> >>               sysram_base_addr + EXYNOS5420_CPU_STATE);
> >> @@ -490,6 +511,28 @@ static struct syscore_ops exynos_pm_syscore_ops = {
> >>       .resume         = exynos_pm_resume,
> >>  };
> >>
> >> +static int notrace exynos_mcpm_cpu_suspend(unsigned long arg)
> >> +{
> >> +     /* MCPM works with HW CPU identifiers */
> >> +     unsigned int mpidr = read_cpuid_mpidr();
> >> +     unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
> >> +     unsigned int cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
> >> +
> >> +     __raw_writel(0x0, sysram_base_addr + EXYNOS5420_CPU_STATE);
> >> +
> >> +     mcpm_set_entry_vector(cpu, cluster, exynos_cpu_resume);
> >> +
> >> +     /*
> >> +      * Residency value passed to mcpm_cpu_suspend back-end
> >> +      * has to be given clear semantics. Set to 0 as a
> >> +      * temporary value.
> >> +      */
> >> +     mcpm_cpu_suspend(0);
> >> +
> >> +     /* return value != 0 means failure */
> >> +     return 1;
> >> +}
> >> +
> >>  /*
> >>   * Suspend Ops
> >>   */
> >> @@ -517,10 +560,17 @@ static int exynos_suspend_enter(suspend_state_t state)
> >>       flush_cache_all();
> >>       s3c_pm_check_store();
> >>
> >> -     ret = cpu_suspend(0, exynos_cpu_suspend);
> >> +     /* Use the MCPM layer to suspend 5420 which is a multi-cluster SoC */
> >> +     if (soc_is_exynos5420() && IS_ENABLED(CONFIG_MCPM))
> >> +             ret = cpu_suspend(0, exynos_mcpm_cpu_suspend);
> >> +     else
> >> +             ret = cpu_suspend(0, exynos_cpu_suspend);
> >>       if (ret)
> >>               return ret;
> >>
> >> +     if (soc_is_exynos5420() && IS_ENABLED(CONFIG_MCPM))
> >> +             mcpm_cpu_powered_up();
> >> +
> >>       s3c_pm_restore_uarts();
> >>
> >>       S3C_PMDBG("%s: wakeup stat: %08x\n", __func__,
> >> --
> >> 2.0.0
> >>
> >>
> 

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Abhilash Kesavan July 8, 2014, 1:39 p.m. UTC | #4
Hi Lorenzo,

On Tue, Jul 8, 2014 at 4:23 PM, Lorenzo Pieralisi
<lorenzo.pieralisi@arm.com> wrote:
> On Fri, Jul 04, 2014 at 10:21:56PM +0100, Abhilash Kesavan wrote:
>> On Sat, Jul 5, 2014 at 2:30 AM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote:
>> > On Sat, 5 Jul 2014, Abhilash Kesavan wrote:
>> >
>> >> Use the MCPM layer to handle core suspend/resume on Exynos5420.
>> >> Also, restore the entry address setup code post-resume.
>> >>
>> >> Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
>> >
>> > Acked-by: Nicolas Pitre <nico@linaro.org>
>> This is one of the last missing bits for exynos MCPM. Thanks for your
>> patient reviews of all the exynos mcpm back-end patches.
>
> Sorry for the delay in getting back to you.
Thanks for your comments.
>
> You still need to handle the residency parameter in the MCPM suspend call
> properly to differentiate between core gating and cluster gating.
I am not too familiar with the cpuidle driver, but I see only cluster
power off state listed in the bL cpuidle driver.
>
> CPUidle might want to request a state that allows for core gating
> residency but not cluster gating one, in that case the last man
> standing must not shutdown the cluster.
For this, I would have to add another state to the bL cpuidle driver
or migrate to using your under-review generic idle state patchset.
Then based on the residency value skip/do cluster power down. Is this
correct ?
>
> This must be handled in the power down function, and it can be done
> in a separate patch since it is an optimization. Current MCPM interface has
> all it is needed to handle this properly, and I am keen on patching the
> CPUidle bL driver to pass the actual residency instead of hardcoding it
> to 0 (ie on TC2 it was not needed, no core gating).
I will look at doing this once the s2r patch gets merged.

Thanks,
Abhilash
>
> Lorenzo
>
>>
>> Regards,
>> Abhilash
>> >
>> >
>> >> ---
>> >> Changes in v2:
>> >>       - Made use of the MCPM suspend/powered_up call-backs
>> >> Changes in v3:
>> >>       - Used the residency value to indicate the entered state
>> >> Changes in v4:
>> >>       - Checked if MCPM has been enabled to prevent build error
>> >> Changes in v5:
>> >>       - Removed the MCPM flags and just used a local flag to
>> >>       indicate that we are suspending.
>> >> Changes in v6:
>> >>       - Read the SYS_PWR_REG value to decide if we are suspending
>> >>       the system.
>> >>       - Restore the SYS_PWR_REG value post-resume.
>> >>       - Modified the comments to reflect the first change.
>> >> Changes in v7:
>> >>       - Add the suspend check in exynos_cpu_power_down() rather
>> >>       than the MCPM back-end.
>> >>       - Clean-up unnecessary changes related to earlier versions.
>> >>
>> >> This has been tested both on an SMDK5420 and Peach Pit Chromebook on
>> >> next-20140704. Nicolas' boot cluster CCI enablement patches are in
>> >> linux-next now.
>> >>
>> >> Here are the dependencies (some of these patches did not apply cleanly):
>> >> 1) Cleanup patches for mach-exynos
>> >> http://comments.gmane.org/gmane.linux.kernel.samsung-soc/33772
>> >>
>> >> 2) PMU cleanup and refactoring for using DT
>> >> https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg671625.html
>> >>
>> >> 3) Exynos5420 PMU/S2R Series
>> >> http://comments.gmane.org/gmane.linux.kernel.samsung-soc/33898
>> >>
>> >> 4) Exynos5420 CPUIdle Series which populates MCPM suspend/powered_up
>> >> call-backs.
>> >> www.gossamer-threads.com/lists/linux/kernel/1945347
>> >> https://patchwork.kernel.org/patch/4357461/
>> >>
>> >> 5) Exynos5420 MCPM cluster power down support
>> >> http://www.spinics.net/lists/arm-kernel/msg339988.html
>> >>
>> >> 6) TPM reset mask patch
>> >> http://www.spinics.net/lists/arm-kernel/msg341884.html
>> >>
>> >>  arch/arm/mach-exynos/mcpm-exynos.c | 32 +++++++++++++++-------
>> >>  arch/arm/mach-exynos/pm.c          | 54 ++++++++++++++++++++++++++++++++++++--
>> >>  2 files changed, 74 insertions(+), 12 deletions(-)
>> >>
>> >> diff --git a/arch/arm/mach-exynos/mcpm-exynos.c b/arch/arm/mach-exynos/mcpm-exynos.c
>> >> index 2dd51cc..74ad772 100644
>> >> --- a/arch/arm/mach-exynos/mcpm-exynos.c
>> >> +++ b/arch/arm/mach-exynos/mcpm-exynos.c
>> >> @@ -15,6 +15,7 @@
>> >>  #include <linux/delay.h>
>> >>  #include <linux/io.h>
>> >>  #include <linux/of_address.h>
>> >> +#include <linux/syscore_ops.h>
>> >>
>> >>  #include <asm/cputype.h>
>> >>  #include <asm/cp15.h>
>> >> @@ -30,6 +31,8 @@
>> >>  #define EXYNOS5420_USE_ARM_CORE_DOWN_STATE   BIT(29)
>> >>  #define EXYNOS5420_USE_L2_COMMON_UP_STATE    BIT(30)
>> >>
>> >> +static void __iomem *ns_sram_base_addr;
>> >> +
>> >>  /*
>> >>   * The common v7_exit_coherency_flush API could not be used because of the
>> >>   * Erratum 799270 workaround. This macro is the same as the common one (in
>> >> @@ -319,10 +322,26 @@ static const struct of_device_id exynos_dt_mcpm_match[] = {
>> >>       {},
>> >>  };
>> >>
>> >> +static void exynos_mcpm_setup_entry_point(void)
>> >> +{
>> >> +     /*
>> >> +      * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
>> >> +      * as part of secondary_cpu_start().  Let's redirect it to the
>> >> +      * mcpm_entry_point(). This is done during both secondary boot-up as
>> >> +      * well as system resume.
>> >> +      */
>> >> +     __raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
>> >> +     __raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
>> >> +     __raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
>> >> +}
>> >> +
>> >> +static struct syscore_ops exynos_mcpm_syscore_ops = {
>> >> +     .resume = exynos_mcpm_setup_entry_point,
>> >> +};
>> >> +
>> >>  static int __init exynos_mcpm_init(void)
>> >>  {
>> >>       struct device_node *node;
>> >> -     void __iomem *ns_sram_base_addr;
>> >>       unsigned int value, i;
>> >>       int ret;
>> >>
>> >> @@ -389,16 +408,9 @@ static int __init exynos_mcpm_init(void)
>> >>               __raw_writel(value, pmu_base_addr + EXYNOS_COMMON_OPTION(i));
>> >>       }
>> >>
>> >> -     /*
>> >> -      * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
>> >> -      * as part of secondary_cpu_start().  Let's redirect it to the
>> >> -      * mcpm_entry_point().
>> >> -      */
>> >> -     __raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
>> >> -     __raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
>> >> -     __raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
>> >> +     exynos_mcpm_setup_entry_point();
>> >>
>> >> -     iounmap(ns_sram_base_addr);
>> >> +     register_syscore_ops(&exynos_mcpm_syscore_ops);
>> >>
>> >>       return ret;
>> >>  }
>> >> diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
>> >> index 69cf678..e2ba1e5 100644
>> >> --- a/arch/arm/mach-exynos/pm.c
>> >> +++ b/arch/arm/mach-exynos/pm.c
>> >> @@ -24,6 +24,7 @@
>> >>
>> >>  #include <asm/cacheflush.h>
>> >>  #include <asm/hardware/cache-l2x0.h>
>> >> +#include <asm/mcpm.h>
>> >>  #include <asm/smp_scu.h>
>> >>  #include <asm/suspend.h>
>> >>
>> >> @@ -123,6 +124,17 @@ static int exynos_irq_set_wake(struct irq_data *data, unsigned int state)
>> >>   */
>> >>  void exynos_cpu_power_down(int cpu)
>> >>  {
>> >> +     if (soc_is_exynos5420() && cpu == 0) {
>> >> +             /*
>> >> +              * Bypass power down for CPU0 during suspend. Check for
>> >> +              * the SYS_PWR_REG value to decide if we are suspending
>> >> +              * the system.
>> >> +              */
>> >> +             int val = __raw_readl(pmu_base_addr +
>> >> +                             EXYNOS5_ARM_CORE0_SYS_PWR_REG);
>> >> +             if (!(val & S5P_CORE_LOCAL_PWR_EN))
>> >> +                     return;
>> >> +     }
>> >>       pmu_raw_writel(0, EXYNOS_ARM_CORE_CONFIGURATION(cpu));
>> >>  }
>> >>
>> >> @@ -318,7 +330,10 @@ static void exynos_pm_prepare(void)
>> >>
>> >>       /* ensure at least INFORM0 has the resume address */
>> >>
>> >> -     pmu_raw_writel(virt_to_phys(exynos_cpu_resume), S5P_INFORM0);
>> >> +     if (soc_is_exynos5420() && IS_ENABLED(CONFIG_MCPM))
>> >> +             pmu_raw_writel(virt_to_phys(mcpm_entry_point), S5P_INFORM0);
>> >> +     else
>> >> +             pmu_raw_writel(virt_to_phys(exynos_cpu_resume), S5P_INFORM0);
>> >>
>> >>       if (soc_is_exynos5420()) {
>> >>               tmp = __raw_readl(pmu_base_addr + EXYNOS5_ARM_L2_OPTION);
>> >> @@ -408,6 +423,12 @@ static void exynos_pm_resume(void)
>> >>       unsigned int tmp;
>> >>
>> >>       if (soc_is_exynos5420()) {
>> >> +             /* Restore the CPU0 low power state register */
>> >> +             tmp = __raw_readl(pmu_base_addr +
>> >> +                     EXYNOS5_ARM_CORE0_SYS_PWR_REG);
>> >> +             pmu_raw_writel(tmp | S5P_CORE_LOCAL_PWR_EN,
>> >> +                     EXYNOS5_ARM_CORE0_SYS_PWR_REG);
>> >> +
>> >>               /* Restore the sysram cpu state register */
>> >>               __raw_writel(exynos5420_cpu_state,
>> >>               sysram_base_addr + EXYNOS5420_CPU_STATE);
>> >> @@ -490,6 +511,28 @@ static struct syscore_ops exynos_pm_syscore_ops = {
>> >>       .resume         = exynos_pm_resume,
>> >>  };
>> >>
>> >> +static int notrace exynos_mcpm_cpu_suspend(unsigned long arg)
>> >> +{
>> >> +     /* MCPM works with HW CPU identifiers */
>> >> +     unsigned int mpidr = read_cpuid_mpidr();
>> >> +     unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
>> >> +     unsigned int cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
>> >> +
>> >> +     __raw_writel(0x0, sysram_base_addr + EXYNOS5420_CPU_STATE);
>> >> +
>> >> +     mcpm_set_entry_vector(cpu, cluster, exynos_cpu_resume);
>> >> +
>> >> +     /*
>> >> +      * Residency value passed to mcpm_cpu_suspend back-end
>> >> +      * has to be given clear semantics. Set to 0 as a
>> >> +      * temporary value.
>> >> +      */
>> >> +     mcpm_cpu_suspend(0);
>> >> +
>> >> +     /* return value != 0 means failure */
>> >> +     return 1;
>> >> +}
>> >> +
>> >>  /*
>> >>   * Suspend Ops
>> >>   */
>> >> @@ -517,10 +560,17 @@ static int exynos_suspend_enter(suspend_state_t state)
>> >>       flush_cache_all();
>> >>       s3c_pm_check_store();
>> >>
>> >> -     ret = cpu_suspend(0, exynos_cpu_suspend);
>> >> +     /* Use the MCPM layer to suspend 5420 which is a multi-cluster SoC */
>> >> +     if (soc_is_exynos5420() && IS_ENABLED(CONFIG_MCPM))
>> >> +             ret = cpu_suspend(0, exynos_mcpm_cpu_suspend);
>> >> +     else
>> >> +             ret = cpu_suspend(0, exynos_cpu_suspend);
>> >>       if (ret)
>> >>               return ret;
>> >>
>> >> +     if (soc_is_exynos5420() && IS_ENABLED(CONFIG_MCPM))
>> >> +             mcpm_cpu_powered_up();
>> >> +
>> >>       s3c_pm_restore_uarts();
>> >>
>> >>       S3C_PMDBG("%s: wakeup stat: %08x\n", __func__,
>> >> --
>> >> 2.0.0
>> >>
>> >>
>>
>
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Lorenzo Pieralisi July 8, 2014, 3:19 p.m. UTC | #5
On Tue, Jul 08, 2014 at 02:39:37PM +0100, Abhilash Kesavan wrote:
> Hi Lorenzo,
> 
> On Tue, Jul 8, 2014 at 4:23 PM, Lorenzo Pieralisi
> <lorenzo.pieralisi@arm.com> wrote:
> > On Fri, Jul 04, 2014 at 10:21:56PM +0100, Abhilash Kesavan wrote:
> >> On Sat, Jul 5, 2014 at 2:30 AM, Nicolas Pitre <nicolas.pitre@linaro.org> wrote:
> >> > On Sat, 5 Jul 2014, Abhilash Kesavan wrote:
> >> >
> >> >> Use the MCPM layer to handle core suspend/resume on Exynos5420.
> >> >> Also, restore the entry address setup code post-resume.
> >> >>
> >> >> Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
> >> >
> >> > Acked-by: Nicolas Pitre <nico@linaro.org>
> >> This is one of the last missing bits for exynos MCPM. Thanks for your
> >> patient reviews of all the exynos mcpm back-end patches.
> >
> > Sorry for the delay in getting back to you.
> Thanks for your comments.
> >
> > You still need to handle the residency parameter in the MCPM suspend call
> > properly to differentiate between core gating and cluster gating.
> I am not too familiar with the cpuidle driver, but I see only cluster
> power off state listed in the bL cpuidle driver.
> >
> > CPUidle might want to request a state that allows for core gating
> > residency but not cluster gating one, in that case the last man
> > standing must not shutdown the cluster.
> For this, I would have to add another state to the bL cpuidle driver
> or migrate to using your under-review generic idle state patchset.
> Then based on the residency value skip/do cluster power down. Is this
> correct ?
> >
> > This must be handled in the power down function, and it can be done
> > in a separate patch since it is an optimization. Current MCPM interface has
> > all it is needed to handle this properly, and I am keen on patching the
> > CPUidle bL driver to pass the actual residency instead of hardcoding it
> > to 0 (ie on TC2 it was not needed, no core gating).
> I will look at doing this once the s2r patch gets merged.

Ok, let's get it done once the CPUidle bL driver DT version gets merged,
I will add a patch that passes the proper residency and you can patch
the MCPM back-end then, until then CPUidle will be suboptimal but I
guess we can live with that for now.

Thanks,
Lorenzo

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diff mbox

Patch

diff --git a/arch/arm/mach-exynos/mcpm-exynos.c b/arch/arm/mach-exynos/mcpm-exynos.c
index 2dd51cc..74ad772 100644
--- a/arch/arm/mach-exynos/mcpm-exynos.c
+++ b/arch/arm/mach-exynos/mcpm-exynos.c
@@ -15,6 +15,7 @@ 
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/of_address.h>
+#include <linux/syscore_ops.h>
 
 #include <asm/cputype.h>
 #include <asm/cp15.h>
@@ -30,6 +31,8 @@ 
 #define EXYNOS5420_USE_ARM_CORE_DOWN_STATE	BIT(29)
 #define EXYNOS5420_USE_L2_COMMON_UP_STATE	BIT(30)
 
+static void __iomem *ns_sram_base_addr;
+
 /*
  * The common v7_exit_coherency_flush API could not be used because of the
  * Erratum 799270 workaround. This macro is the same as the common one (in
@@ -319,10 +322,26 @@  static const struct of_device_id exynos_dt_mcpm_match[] = {
 	{},
 };
 
+static void exynos_mcpm_setup_entry_point(void)
+{
+	/*
+	 * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
+	 * as part of secondary_cpu_start().  Let's redirect it to the
+	 * mcpm_entry_point(). This is done during both secondary boot-up as
+	 * well as system resume.
+	 */
+	__raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
+	__raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
+	__raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
+}
+
+static struct syscore_ops exynos_mcpm_syscore_ops = {
+	.resume	= exynos_mcpm_setup_entry_point,
+};
+
 static int __init exynos_mcpm_init(void)
 {
 	struct device_node *node;
-	void __iomem *ns_sram_base_addr;
 	unsigned int value, i;
 	int ret;
 
@@ -389,16 +408,9 @@  static int __init exynos_mcpm_init(void)
 		__raw_writel(value, pmu_base_addr + EXYNOS_COMMON_OPTION(i));
 	}
 
-	/*
-	 * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
-	 * as part of secondary_cpu_start().  Let's redirect it to the
-	 * mcpm_entry_point().
-	 */
-	__raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
-	__raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
-	__raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
+	exynos_mcpm_setup_entry_point();
 
-	iounmap(ns_sram_base_addr);
+	register_syscore_ops(&exynos_mcpm_syscore_ops);
 
 	return ret;
 }
diff --git a/arch/arm/mach-exynos/pm.c b/arch/arm/mach-exynos/pm.c
index 69cf678..e2ba1e5 100644
--- a/arch/arm/mach-exynos/pm.c
+++ b/arch/arm/mach-exynos/pm.c
@@ -24,6 +24,7 @@ 
 
 #include <asm/cacheflush.h>
 #include <asm/hardware/cache-l2x0.h>
+#include <asm/mcpm.h>
 #include <asm/smp_scu.h>
 #include <asm/suspend.h>
 
@@ -123,6 +124,17 @@  static int exynos_irq_set_wake(struct irq_data *data, unsigned int state)
  */
 void exynos_cpu_power_down(int cpu)
 {
+	if (soc_is_exynos5420() && cpu == 0) {
+		/*
+		 * Bypass power down for CPU0 during suspend. Check for
+		 * the SYS_PWR_REG value to decide if we are suspending
+		 * the system.
+		 */
+		int val = __raw_readl(pmu_base_addr +
+				EXYNOS5_ARM_CORE0_SYS_PWR_REG);
+		if (!(val & S5P_CORE_LOCAL_PWR_EN))
+			return;
+	}
 	pmu_raw_writel(0, EXYNOS_ARM_CORE_CONFIGURATION(cpu));
 }
 
@@ -318,7 +330,10 @@  static void exynos_pm_prepare(void)
 
 	/* ensure at least INFORM0 has the resume address */
 
-	pmu_raw_writel(virt_to_phys(exynos_cpu_resume), S5P_INFORM0);
+	if (soc_is_exynos5420() && IS_ENABLED(CONFIG_MCPM))
+		pmu_raw_writel(virt_to_phys(mcpm_entry_point), S5P_INFORM0);
+	else
+		pmu_raw_writel(virt_to_phys(exynos_cpu_resume), S5P_INFORM0);
 
 	if (soc_is_exynos5420()) {
 		tmp = __raw_readl(pmu_base_addr + EXYNOS5_ARM_L2_OPTION);
@@ -408,6 +423,12 @@  static void exynos_pm_resume(void)
 	unsigned int tmp;
 
 	if (soc_is_exynos5420()) {
+		/* Restore the CPU0 low power state register */
+		tmp = __raw_readl(pmu_base_addr +
+			EXYNOS5_ARM_CORE0_SYS_PWR_REG);
+		pmu_raw_writel(tmp | S5P_CORE_LOCAL_PWR_EN,
+			EXYNOS5_ARM_CORE0_SYS_PWR_REG);
+
 		/* Restore the sysram cpu state register */
 		__raw_writel(exynos5420_cpu_state,
 		sysram_base_addr + EXYNOS5420_CPU_STATE);
@@ -490,6 +511,28 @@  static struct syscore_ops exynos_pm_syscore_ops = {
 	.resume		= exynos_pm_resume,
 };
 
+static int notrace exynos_mcpm_cpu_suspend(unsigned long arg)
+{
+	/* MCPM works with HW CPU identifiers */
+	unsigned int mpidr = read_cpuid_mpidr();
+	unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+	unsigned int cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+
+	__raw_writel(0x0, sysram_base_addr + EXYNOS5420_CPU_STATE);
+
+	mcpm_set_entry_vector(cpu, cluster, exynos_cpu_resume);
+
+	/*
+	 * Residency value passed to mcpm_cpu_suspend back-end
+	 * has to be given clear semantics. Set to 0 as a
+	 * temporary value.
+	 */
+	mcpm_cpu_suspend(0);
+
+	/* return value != 0 means failure */
+	return 1;
+}
+
 /*
  * Suspend Ops
  */
@@ -517,10 +560,17 @@  static int exynos_suspend_enter(suspend_state_t state)
 	flush_cache_all();
 	s3c_pm_check_store();
 
-	ret = cpu_suspend(0, exynos_cpu_suspend);
+	/* Use the MCPM layer to suspend 5420 which is a multi-cluster SoC */
+	if (soc_is_exynos5420() && IS_ENABLED(CONFIG_MCPM))
+		ret = cpu_suspend(0, exynos_mcpm_cpu_suspend);
+	else
+		ret = cpu_suspend(0, exynos_cpu_suspend);
 	if (ret)
 		return ret;
 
+	if (soc_is_exynos5420() && IS_ENABLED(CONFIG_MCPM))
+		mcpm_cpu_powered_up();
+
 	s3c_pm_restore_uarts();
 
 	S3C_PMDBG("%s: wakeup stat: %08x\n", __func__,