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[PATCH v4 1/5] ACPI / processor_idle: introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE

Started bySudeep Holla <sudeep.holla@arm.com>
First post2016-04-19 14:40 +0200
Last post2016-04-20 12:10 +0200
Articles 5 — 3 participants

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  [PATCH v4 1/5] ACPI / processor_idle: introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE Sudeep Holla <sudeep.holla@arm.com> - 2016-04-19 14:40 +0200
    Re: [PATCH v4 1/5] ACPI / processor_idle: introduce  ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE kbuild test robot <lkp@intel.com> - 2016-04-19 15:00 +0200
      Re: [PATCH v4 1/5] ACPI / processor_idle: introduce  ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE Sudeep Holla <sudeep.holla@arm.com> - 2016-04-19 15:10 +0200
    Re: [PATCH v4 1/5] ACPI / processor_idle: introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE Vikas Sajjan <sajjan.linux@gmail.com> - 2016-04-20 12:00 +0200
      Re: [PATCH v4 1/5] ACPI / processor_idle: introduce  ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE Sudeep Holla <sudeep.holla@arm.com> - 2016-04-20 12:10 +0200

#1382450 — [PATCH v4 1/5] ACPI / processor_idle: introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE

FromSudeep Holla <sudeep.holla@arm.com>
Date2016-04-19 14:40 +0200
Subject[PATCH v4 1/5] ACPI / processor_idle: introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE
Message-ID<rpD6G-6Tc-11@gated-at.bofh.it>
ACPI 6.0 adds a new method to specify the CPU idle states(C-states)
called Low Power Idle(LPI) states. Since new architectures like ARM64
use only LPIs, introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE to
encapsulate all the code supporting the old style C-states(_CST)

This patch will help to extend the processor_idle module to support
LPI.

Cc: x86@kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 arch/ia64/Kconfig             |  1 +
 arch/x86/Kconfig              |  1 +
 drivers/acpi/Kconfig          |  3 ++
 drivers/acpi/processor_idle.c | 74 +++++++++++++++++++++++++++++--------------
 include/acpi/processor.h      |  3 +-
 5 files changed, 57 insertions(+), 25 deletions(-)

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index b534ebab36ea..717de2a146e2 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -16,6 +16,7 @@ config IA64
 	select PCI if (!IA64_HP_SIM)
 	select ACPI if (!IA64_HP_SIM)
 	select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
+	select ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE if ACPI
 	select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
 	select HAVE_UNSTABLE_SCHED_CLOCK
 	select HAVE_IDE
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2dc18605831f..eb03fd0d63b9 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -37,6 +37,7 @@ config X86
 	select ARCH_MIGHT_HAVE_ACPI_PDC		if ACPI
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO
+	select ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE if ACPI
 	select ARCH_SUPPORTS_ATOMIC_RMW
 	select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
 	select ARCH_SUPPORTS_INT128		if X86_64
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index 82b96ee8624c..ec289078667c 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -48,6 +48,9 @@ config ACPI_LEGACY_TABLES_LOOKUP
 config ARCH_MIGHT_HAVE_ACPI_PDC
 	bool
 
+config ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE
+	bool
+
 config ACPI_GENERIC_GSI
 	bool
 
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 444e3745c8b3..1f3fe54194b5 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -59,6 +59,12 @@ module_param(latency_factor, uint, 0644);
 
 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
 
+struct cpuidle_driver acpi_idle_driver = {
+	.name =		"acpi_idle",
+	.owner =	THIS_MODULE,
+};
+
+#ifdef CONFIG_ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE
 static
 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
 
@@ -804,11 +810,6 @@ static void acpi_idle_enter_freeze(struct cpuidle_device *dev,
 	acpi_idle_do_entry(cx);
 }
 
-struct cpuidle_driver acpi_idle_driver = {
-	.name =		"acpi_idle",
-	.owner =	THIS_MODULE,
-};
-
 /**
  * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
  * device i.e. per-cpu data
@@ -925,6 +926,49 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
 	return 0;
 }
 
+static inline void acpi_processor_cstate_first_run_checks(void)
+{
+	static int first_run;
+
+	if (first_run)
+		return;
+	dmi_check_system(processor_power_dmi_table);
+	max_cstate = acpi_processor_cstate_check(max_cstate);
+	if (max_cstate < ACPI_C_STATES_MAX)
+		pr_notice("ACPI: processor limited to max C-state %d\n",
+			  max_cstate);
+	first_run++;
+
+	if (acpi_gbl_FADT.cst_control && !nocst) {
+		status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
+					    acpi_gbl_FADT.cst_control, 8);
+		if (ACPI_FAILURE(status))
+			ACPI_EXCEPTION((AE_INFO, status,
+					"Notifying BIOS of _CST ability failed"));
+	}
+}
+#else
+
+static inline int disabled_by_idle_boot_param(void) { return 0; }
+static inline void acpi_processor_cstate_first_run_checks(void) { }
+static int acpi_processor_get_power_info(struct acpi_processor *pr)
+{
+	return -ENODEV;
+}
+
+static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
+					   struct cpuidle_device *dev)
+{
+	return -EINVAL;
+}
+
+static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
+{
+	return -EINVAL;
+}
+
+#endif
+
 int acpi_processor_hotplug(struct acpi_processor *pr)
 {
 	int ret = 0;
@@ -1018,29 +1062,11 @@ int acpi_processor_power_init(struct acpi_processor *pr)
 	acpi_status status;
 	int retval;
 	struct cpuidle_device *dev;
-	static int first_run;
 
 	if (disabled_by_idle_boot_param())
 		return 0;
 
-	if (!first_run) {
-		dmi_check_system(processor_power_dmi_table);
-		max_cstate = acpi_processor_cstate_check(max_cstate);
-		if (max_cstate < ACPI_C_STATES_MAX)
-			printk(KERN_NOTICE
-			       "ACPI: processor limited to max C-state %d\n",
-			       max_cstate);
-		first_run++;
-	}
-
-	if (acpi_gbl_FADT.cst_control && !nocst) {
-		status =
-		    acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
-		if (ACPI_FAILURE(status)) {
-			ACPI_EXCEPTION((AE_INFO, status,
-					"Notifying BIOS of _CST ability failed"));
-		}
-	}
+	acpi_processor_cstate_first_run_checks();
 
 	acpi_processor_get_power_info(pr);
 	pr->flags.power_setup_done = 1;
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 6f1805dd5d3c..50f2423d31fa 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -242,7 +242,8 @@ extern int acpi_processor_get_performance_info(struct acpi_processor *pr);
 DECLARE_PER_CPU(struct acpi_processor *, processors);
 extern struct acpi_processor_errata errata;
 
-#ifdef ARCH_HAS_POWER_INIT
+#if defined(ARCH_HAS_POWER_INIT) && \
+	defined(CONFIG_ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE)
 void acpi_processor_power_init_bm_check(struct acpi_processor_flags *flags,
 					unsigned int cpu);
 int acpi_processor_ffh_cstate_probe(unsigned int cpu,
-- 
1.9.1

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#1382484 — Re: [PATCH v4 1/5] ACPI / processor_idle: introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE

Fromkbuild test robot <lkp@intel.com>
Date2016-04-19 15:00 +0200
SubjectRe: [PATCH v4 1/5] ACPI / processor_idle: introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE
Message-ID<rpDq2-71o-1@gated-at.bofh.it>
In reply to#1382450

[Multipart message — attachments visible in raw view] — view raw

Hi,

[auto build test ERROR on pm/linux-next]
[also build test ERROR on v4.6-rc4 next-20160419]
[if your patch is applied to the wrong git tree, please drop us a note to help improving the system]

url:    https://github.com/0day-ci/linux/commits/Sudeep-Holla/ACPI-processor_idle-Add-ACPI-v6-0-LPI-support/20160419-203500
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
config: i386-randconfig-x000-201616 (attached as .config)
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

Note: the linux-review/Sudeep-Holla/ACPI-processor_idle-Add-ACPI-v6-0-LPI-support/20160419-203500 HEAD c51fc2a756d7b0dce908a4ca043d1d458c400af5 builds fine.
      It only hurts bisectibility.

All error/warnings (new ones prefixed by >>):

   drivers/acpi/processor_idle.c: In function 'acpi_processor_cstate_first_run_checks':
>> drivers/acpi/processor_idle.c:943:3: error: 'status' undeclared (first use in this function)
      status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
      ^
   drivers/acpi/processor_idle.c:943:3: note: each undeclared identifier is reported only once for each function it appears in
   drivers/acpi/processor_idle.c: In function 'acpi_processor_power_init':
>> drivers/acpi/processor_idle.c:1062:14: warning: unused variable 'status' [-Wunused-variable]
     acpi_status status;
                 ^

vim +/status +943 drivers/acpi/processor_idle.c

   937		if (max_cstate < ACPI_C_STATES_MAX)
   938			pr_notice("ACPI: processor limited to max C-state %d\n",
   939				  max_cstate);
   940		first_run++;
   941	
   942		if (acpi_gbl_FADT.cst_control && !nocst) {
 > 943			status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
   944						    acpi_gbl_FADT.cst_control, 8);
   945			if (ACPI_FAILURE(status))
   946				ACPI_EXCEPTION((AE_INFO, status,
   947						"Notifying BIOS of _CST ability failed"));
   948		}
   949	}
   950	#else
   951	
   952	static inline int disabled_by_idle_boot_param(void) { return 0; }
   953	static inline void acpi_processor_cstate_first_run_checks(void) { }
   954	static int acpi_processor_get_power_info(struct acpi_processor *pr)
   955	{
   956		return -ENODEV;
   957	}
   958	
   959	static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
   960						   struct cpuidle_device *dev)
   961	{
   962		return -EINVAL;
   963	}
   964	
   965	static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
   966	{
   967		return -EINVAL;
   968	}
   969	
   970	#endif
   971	
   972	int acpi_processor_hotplug(struct acpi_processor *pr)
   973	{
   974		int ret = 0;
   975		struct cpuidle_device *dev;
   976	
   977		if (disabled_by_idle_boot_param())
   978			return 0;
   979	
   980		if (nocst)
   981			return -ENODEV;
   982	
   983		if (!pr->flags.power_setup_done)
   984			return -ENODEV;
   985	
   986		dev = per_cpu(acpi_cpuidle_device, pr->id);
   987		cpuidle_pause_and_lock();
   988		cpuidle_disable_device(dev);
   989		acpi_processor_get_power_info(pr);
   990		if (pr->flags.power) {
   991			acpi_processor_setup_cpuidle_cx(pr, dev);
   992			ret = cpuidle_enable_device(dev);
   993		}
   994		cpuidle_resume_and_unlock();
   995	
   996		return ret;
   997	}
   998	
   999	int acpi_processor_cst_has_changed(struct acpi_processor *pr)
  1000	{
  1001		int cpu;
  1002		struct acpi_processor *_pr;
  1003		struct cpuidle_device *dev;
  1004	
  1005		if (disabled_by_idle_boot_param())
  1006			return 0;
  1007	
  1008		if (nocst)
  1009			return -ENODEV;
  1010	
  1011		if (!pr->flags.power_setup_done)
  1012			return -ENODEV;
  1013	
  1014		/*
  1015		 * FIXME:  Design the ACPI notification to make it once per
  1016		 * system instead of once per-cpu.  This condition is a hack
  1017		 * to make the code that updates C-States be called once.
  1018		 */
  1019	
  1020		if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
  1021	
  1022			/* Protect against cpu-hotplug */
  1023			get_online_cpus();
  1024			cpuidle_pause_and_lock();
  1025	
  1026			/* Disable all cpuidle devices */
  1027			for_each_online_cpu(cpu) {
  1028				_pr = per_cpu(processors, cpu);
  1029				if (!_pr || !_pr->flags.power_setup_done)
  1030					continue;
  1031				dev = per_cpu(acpi_cpuidle_device, cpu);
  1032				cpuidle_disable_device(dev);
  1033			}
  1034	
  1035			/* Populate Updated C-state information */
  1036			acpi_processor_get_power_info(pr);
  1037			acpi_processor_setup_cpuidle_states(pr);
  1038	
  1039			/* Enable all cpuidle devices */
  1040			for_each_online_cpu(cpu) {
  1041				_pr = per_cpu(processors, cpu);
  1042				if (!_pr || !_pr->flags.power_setup_done)
  1043					continue;
  1044				acpi_processor_get_power_info(_pr);
  1045				if (_pr->flags.power) {
  1046					dev = per_cpu(acpi_cpuidle_device, cpu);
  1047					acpi_processor_setup_cpuidle_cx(_pr, dev);
  1048					cpuidle_enable_device(dev);
  1049				}
  1050			}
  1051			cpuidle_resume_and_unlock();
  1052			put_online_cpus();
  1053		}
  1054	
  1055		return 0;
  1056	}
  1057	
  1058	static int acpi_processor_registered;
  1059	
  1060	int acpi_processor_power_init(struct acpi_processor *pr)
  1061	{
> 1062		acpi_status status;
  1063		int retval;
  1064		struct cpuidle_device *dev;
  1065	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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#1382493 — Re: [PATCH v4 1/5] ACPI / processor_idle: introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE

FromSudeep Holla <sudeep.holla@arm.com>
Date2016-04-19 15:10 +0200
SubjectRe: [PATCH v4 1/5] ACPI / processor_idle: introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE
Message-ID<rpDzI-7oD-17@gated-at.bofh.it>
In reply to#1382484
Hi,

On 19/04/16 13:49, kbuild test robot wrote:
> Hi,
>
> [auto build test ERROR on pm/linux-next]
> [also build test ERROR on v4.6-rc4 next-20160419]
> [if your patch is applied to the wrong git tree, please drop us a note to help improving the system]
>
> url:    https://github.com/0day-ci/linux/commits/Sudeep-Holla/ACPI-processor_idle-Add-ACPI-v6-0-LPI-support/20160419-203500
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
> config: i386-randconfig-x000-201616 (attached as .config)
> reproduce:
>          # save the attached .config to linux build tree
>          make ARCH=i386
>
> Note: the linux-review/Sudeep-Holla/ACPI-processor_idle-Add-ACPI-v6-0-LPI-support/20160419-203500 HEAD c51fc2a756d7b0dce908a4ca043d1d458c400af5 builds fine.
>        It only hurts bisectibility.
>

Thanks for the report, it's now fixed locally.
It will part of the next version.

--
Regards,
Sudeep

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#1383233

FromVikas Sajjan <sajjan.linux@gmail.com>
Date2016-04-20 12:00 +0200
Message-ID<rpX5p-5R6-25@gated-at.bofh.it>
In reply to#1382450
Hi Sudeep,

On Tue, Apr 19, 2016 at 6:00 PM, Sudeep Holla <sudeep.holla@arm.com> wrote:
> ACPI 6.0 adds a new method to specify the CPU idle states(C-states)
> called Low Power Idle(LPI) states. Since new architectures like ARM64
> use only LPIs, introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE to
> encapsulate all the code supporting the old style C-states(_CST)
>
> This patch will help to extend the processor_idle module to support
> LPI.
>
> Cc: x86@kernel.org
> Cc: linux-ia64@vger.kernel.org
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> ---
>  arch/ia64/Kconfig             |  1 +
>  arch/x86/Kconfig              |  1 +
>  drivers/acpi/Kconfig          |  3 ++
>  drivers/acpi/processor_idle.c | 74 +++++++++++++++++++++++++++++--------------
>  include/acpi/processor.h      |  3 +-
>  5 files changed, 57 insertions(+), 25 deletions(-)
>
> diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
> index b534ebab36ea..717de2a146e2 100644
> --- a/arch/ia64/Kconfig
> +++ b/arch/ia64/Kconfig
> @@ -16,6 +16,7 @@ config IA64
>         select PCI if (!IA64_HP_SIM)
>         select ACPI if (!IA64_HP_SIM)
>         select ACPI_SYSTEM_POWER_STATES_SUPPORT if ACPI
> +       select ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE if ACPI
>         select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI
>         select HAVE_UNSTABLE_SCHED_CLOCK
>         select HAVE_IDE
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 2dc18605831f..eb03fd0d63b9 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -37,6 +37,7 @@ config X86
>         select ARCH_MIGHT_HAVE_ACPI_PDC         if ACPI
>         select ARCH_MIGHT_HAVE_PC_PARPORT
>         select ARCH_MIGHT_HAVE_PC_SERIO
> +       select ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE if ACPI
>         select ARCH_SUPPORTS_ATOMIC_RMW
>         select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT
>         select ARCH_SUPPORTS_INT128             if X86_64
> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> index 82b96ee8624c..ec289078667c 100644
> --- a/drivers/acpi/Kconfig
> +++ b/drivers/acpi/Kconfig
> @@ -48,6 +48,9 @@ config ACPI_LEGACY_TABLES_LOOKUP
>  config ARCH_MIGHT_HAVE_ACPI_PDC
>         bool
>
> +config ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE
> +       bool
> +
>  config ACPI_GENERIC_GSI
>         bool
>
> diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
> index 444e3745c8b3..1f3fe54194b5 100644
> --- a/drivers/acpi/processor_idle.c
> +++ b/drivers/acpi/processor_idle.c
> @@ -59,6 +59,12 @@ module_param(latency_factor, uint, 0644);
>
>  static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
>
> +struct cpuidle_driver acpi_idle_driver = {
> +       .name =         "acpi_idle",
> +       .owner =        THIS_MODULE,
> +};
> +
> +#ifdef CONFIG_ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE
>  static
>  DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
>
> @@ -804,11 +810,6 @@ static void acpi_idle_enter_freeze(struct cpuidle_device *dev,
>         acpi_idle_do_entry(cx);
>  }
>
> -struct cpuidle_driver acpi_idle_driver = {
> -       .name =         "acpi_idle",
> -       .owner =        THIS_MODULE,
> -};
> -
>  /**
>   * acpi_processor_setup_cpuidle_cx - prepares and configures CPUIDLE
>   * device i.e. per-cpu data
> @@ -925,6 +926,49 @@ static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
>         return 0;
>  }
>
> +static inline void acpi_processor_cstate_first_run_checks(void)
> +{
> +       static int first_run;
> +
> +       if (first_run)
> +               return;
> +       dmi_check_system(processor_power_dmi_table);
> +       max_cstate = acpi_processor_cstate_check(max_cstate);
> +       if (max_cstate < ACPI_C_STATES_MAX)
> +               pr_notice("ACPI: processor limited to max C-state %d\n",
> +                         max_cstate);
> +       first_run++;
> +
> +       if (acpi_gbl_FADT.cst_control && !nocst) {
> +               status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
> +                                           acpi_gbl_FADT.cst_control, 8);
> +               if (ACPI_FAILURE(status))
> +                       ACPI_EXCEPTION((AE_INFO, status,
> +                                       "Notifying BIOS of _CST ability failed"));
> +       }
> +}
> +#else
> +
> +static inline int disabled_by_idle_boot_param(void) { return 0; }
> +static inline void acpi_processor_cstate_first_run_checks(void) { }
> +static int acpi_processor_get_power_info(struct acpi_processor *pr)
> +{
> +       return -ENODEV;
> +}
> +
> +static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
> +                                          struct cpuidle_device *dev)
> +{
> +       return -EINVAL;
> +}
> +
> +static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
> +{
> +       return -EINVAL;
> +}
> +
> +#endif
> +
>  int acpi_processor_hotplug(struct acpi_processor *pr)
>  {
>         int ret = 0;
> @@ -1018,29 +1062,11 @@ int acpi_processor_power_init(struct acpi_processor *pr)
>         acpi_status status;
>         int retval;
>         struct cpuidle_device *dev;
> -       static int first_run;
>
>         if (disabled_by_idle_boot_param())
>                 return 0;
>
> -       if (!first_run) {
> -               dmi_check_system(processor_power_dmi_table);
> -               max_cstate = acpi_processor_cstate_check(max_cstate);
> -               if (max_cstate < ACPI_C_STATES_MAX)
> -                       printk(KERN_NOTICE
> -                              "ACPI: processor limited to max C-state %d\n",
> -                              max_cstate);
> -               first_run++;
> -       }
> -
> -       if (acpi_gbl_FADT.cst_control && !nocst) {
> -               status =
> -                   acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
> -               if (ACPI_FAILURE(status)) {
> -                       ACPI_EXCEPTION((AE_INFO, status,
> -                                       "Notifying BIOS of _CST ability failed"));
> -               }
> -       }
> +       acpi_processor_cstate_first_run_checks();
>
>         acpi_processor_get_power_info(pr);
>         pr->flags.power_setup_done = 1;

Not related to your change,
The acpi_processor_get_power_info() function can return failure, so i
thought it makes sense to check for the return value
and then set the  flag pr->flags.power_setup_done appropriately.


> diff --git a/include/acpi/processor.h b/include/acpi/processor.h
> index 6f1805dd5d3c..50f2423d31fa 100644
> --- a/include/acpi/processor.h
> +++ b/include/acpi/processor.h
> @@ -242,7 +242,8 @@ extern int acpi_processor_get_performance_info(struct acpi_processor *pr);
>  DECLARE_PER_CPU(struct acpi_processor *, processors);
>  extern struct acpi_processor_errata errata;
>
> -#ifdef ARCH_HAS_POWER_INIT
> +#if defined(ARCH_HAS_POWER_INIT) && \
> +       defined(CONFIG_ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE)
>  void acpi_processor_power_init_bm_check(struct acpi_processor_flags *flags,
>                                         unsigned int cpu);
>  int acpi_processor_ffh_cstate_probe(unsigned int cpu,
> --
> 1.9.1
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

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#1383238 — Re: [PATCH v4 1/5] ACPI / processor_idle: introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE

FromSudeep Holla <sudeep.holla@arm.com>
Date2016-04-20 12:10 +0200
SubjectRe: [PATCH v4 1/5] ACPI / processor_idle: introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE
Message-ID<rpXf4-6cK-19@gated-at.bofh.it>
In reply to#1383233

On 20/04/16 10:56, Vikas Sajjan wrote:
> Hi Sudeep,
>
> On Tue, Apr 19, 2016 at 6:00 PM, Sudeep Holla <sudeep.holla@arm.com> wrote:
>> ACPI 6.0 adds a new method to specify the CPU idle states(C-states)
>> called Low Power Idle(LPI) states. Since new architectures like ARM64
>> use only LPIs, introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE to
>> encapsulate all the code supporting the old style C-states(_CST)
>>
>> This patch will help to extend the processor_idle module to support
>> LPI.
>>

[...]

>> @@ -1018,29 +1062,11 @@ int acpi_processor_power_init(struct acpi_processor *pr)
>>          acpi_status status;
>>          int retval;
>>          struct cpuidle_device *dev;
>> -       static int first_run;
>>
>>          if (disabled_by_idle_boot_param())
>>                  return 0;
>>
>> -       if (!first_run) {
>> -               dmi_check_system(processor_power_dmi_table);
>> -               max_cstate = acpi_processor_cstate_check(max_cstate);
>> -               if (max_cstate < ACPI_C_STATES_MAX)
>> -                       printk(KERN_NOTICE
>> -                              "ACPI: processor limited to max C-state %d\n",
>> -                              max_cstate);
>> -               first_run++;
>> -       }
>> -
>> -       if (acpi_gbl_FADT.cst_control && !nocst) {
>> -               status =
>> -                   acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
>> -               if (ACPI_FAILURE(status)) {
>> -                       ACPI_EXCEPTION((AE_INFO, status,
>> -                                       "Notifying BIOS of _CST ability failed"));
>> -               }
>> -       }
>> +       acpi_processor_cstate_first_run_checks();
>>
>>          acpi_processor_get_power_info(pr);
>>          pr->flags.power_setup_done = 1;
>
> Not related to your change,
> The acpi_processor_get_power_info() function can return failure, so i
> thought it makes sense to check for the return value
> and then set the  flag pr->flags.power_setup_done appropriately.
>

Makes sense, will do that.

-- 
Regards,
Sudeep

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