diff mbox

[2/2] drivers: firmware: psci: add system suspend support

Message ID 1434462640-19613-3-git-send-email-sudeep.holla@arm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Sudeep Holla June 16, 2015, 1:50 p.m. UTC
PSCI v1.0 introduces a new API called PSCI_SYSTEM_SUSPEND. This API
provides the mechanism by which the calling OS can request entry into
the deepest possible system sleep state.

It meets all the necessary preconditions for entrying suspend to RAM
state in Linux. This patch adds support for PSCI_SYSTEM_SUSPEND in psci
firmware and registers a psci system suspend operation to implement the
suspend-to-RAM(s2r) in a generic way on all the platforms implementing
PSCI.

Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/firmware/psci.c   | 39 +++++++++++++++++++++++++++++++++++++++
 include/uapi/linux/psci.h |  2 ++
 2 files changed, 41 insertions(+)

Comments

Lorenzo Pieralisi June 17, 2015, 3:08 p.m. UTC | #1
On Tue, Jun 16, 2015 at 02:50:40PM +0100, Sudeep Holla wrote:
> PSCI v1.0 introduces a new API called PSCI_SYSTEM_SUSPEND. This API
> provides the mechanism by which the calling OS can request entry into
> the deepest possible system sleep state.
> 
> It meets all the necessary preconditions for entrying suspend to RAM

s/entrying/entering/

> state in Linux. This patch adds support for PSCI_SYSTEM_SUSPEND in psci
> firmware and registers a psci system suspend operation to implement the
> suspend-to-RAM(s2r) in a generic way on all the platforms implementing
> PSCI.
> 
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> ---
>  drivers/firmware/psci.c   | 39 +++++++++++++++++++++++++++++++++++++++
>  include/uapi/linux/psci.h |  2 ++
>  2 files changed, 41 insertions(+)
> 
> diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
> index 68d0c2f6d004..4f0359516119 100644
> --- a/drivers/firmware/psci.c
> +++ b/drivers/firmware/psci.c
> @@ -20,11 +20,13 @@
>  #include <linux/printk.h>
>  #include <linux/psci.h>
>  #include <linux/reboot.h>
> +#include <linux/suspend.h>
>  
>  #include <uapi/linux/psci.h>
>  
>  #include <asm/system_misc.h>
>  #include <asm/smp_plat.h>
> +#include <asm/suspend.h>
>  
>  /*
>   * While a 64-bit OS can make calls with SMC32 calling conventions, for some
> @@ -222,6 +224,41 @@ static int __init psci_features(u32 psci_func_id)
>  			      psci_func_id, 0, 0);
>  }
>  
> +static int psci_system_suspend(unsigned long entry_point)
> +{
> +	return invoke_psci_fn(PSCI_0_2_FN_NATIVE(SYSTEM_SUSPEND),
> +			      entry_point, 0, 0);
> +}
> +
> +static int psci_system_suspend_finisher(unsigned long unused)
> +{
> +	return psci_system_suspend(virt_to_phys(cpu_resume));

Do we really need another level of indirection ? I would invoke
the PSCI function from here.

> +}
> +
> +static int psci_system_suspend_enter(suspend_state_t state)
> +{
> +	if (state != PM_SUSPEND_MEM)
> +		return 0;

suspend_valid_only_mem should check this, am I missing something ?

You should not return 0 on failure anyway.

> +
> +	return cpu_suspend(0, psci_system_suspend_finisher);
> +}
> +
> +static const struct platform_suspend_ops psci_suspend_ops = {
> +	.valid          = suspend_valid_only_mem,
> +	.enter          = psci_system_suspend_enter,
> +};
> +
> +static void __init psci_init_system_suspend(void)
> +{
> +	if (!IS_ENABLED(CONFIG_SUSPEND))
> +		return;
> +
> +	if (psci_features(PSCI_0_2_FN_NATIVE(SYSTEM_SUSPEND)))

Nit: I think we should use a 1_0 tag here for SYSTEM_SUSPEND.

> +		return;
> +
> +	suspend_set_ops(&psci_suspend_ops);
> +}
> +
>  static void __init psci_init_cpu_suspend(void)
>  {
>  	int feature = psci_features(psci_function_id[PSCI_FN_CPU_SUSPEND]);
> @@ -310,6 +347,8 @@ static int __init psci_probe(void)
>  
>  	psci_init_cpu_suspend();
>  
> +	psci_init_system_suspend();
> +
>  	return 0;
>  }
>  
> diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
> index 2598d7c9bf20..62b054524819 100644
> --- a/include/uapi/linux/psci.h
> +++ b/include/uapi/linux/psci.h
> @@ -39,12 +39,14 @@
>  #define PSCI_0_2_FN_MIGRATE_INFO_UP_CPU		PSCI_0_2_FN(7)
>  #define PSCI_0_2_FN_SYSTEM_OFF			PSCI_0_2_FN(8)
>  #define PSCI_0_2_FN_SYSTEM_RESET		PSCI_0_2_FN(9)
> +#define PSCI_0_2_FN_SYSTEM_SUSPEND		PSCI_0_2_FN(14)

I think you should keep versioning consistent, namely SYSTEM_SUSPEND
is a 1.0 only feature and the tag should reflect that.

>  #define PSCI_0_2_FN64_CPU_SUSPEND		PSCI_0_2_FN64(1)
>  #define PSCI_0_2_FN64_CPU_ON			PSCI_0_2_FN64(3)
>  #define PSCI_0_2_FN64_AFFINITY_INFO		PSCI_0_2_FN64(4)
>  #define PSCI_0_2_FN64_MIGRATE			PSCI_0_2_FN64(5)
>  #define PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU	PSCI_0_2_FN64(7)
> +#define PSCI_0_2_FN64_SYSTEM_SUSPEND		PSCI_0_2_FN64(14)

Ditto.

Thanks,
Lorenzo

>  
>  #define PSCI_1_0_FN_PSCI_FEATURES		PSCI_0_2_FN(10)
>  
> -- 
> 1.9.1
>
Sudeep Holla June 17, 2015, 3:41 p.m. UTC | #2
On 17/06/15 16:08, Lorenzo Pieralisi wrote:
> On Tue, Jun 16, 2015 at 02:50:40PM +0100, Sudeep Holla wrote:
>> PSCI v1.0 introduces a new API called PSCI_SYSTEM_SUSPEND. This API
>> provides the mechanism by which the calling OS can request entry into
>> the deepest possible system sleep state.
>>
>> It meets all the necessary preconditions for entrying suspend to RAM
>
> s/entrying/entering/
>
>> state in Linux. This patch adds support for PSCI_SYSTEM_SUSPEND in psci
>> firmware and registers a psci system suspend operation to implement the
>> suspend-to-RAM(s2r) in a generic way on all the platforms implementing
>> PSCI.
>>
>> Cc: Mark Rutland <mark.rutland@arm.com>
>> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
>> ---
>>   drivers/firmware/psci.c   | 39 +++++++++++++++++++++++++++++++++++++++
>>   include/uapi/linux/psci.h |  2 ++
>>   2 files changed, 41 insertions(+)
>>
>> diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
>> index 68d0c2f6d004..4f0359516119 100644
>> --- a/drivers/firmware/psci.c
>> +++ b/drivers/firmware/psci.c
>> @@ -20,11 +20,13 @@
>>   #include <linux/printk.h>
>>   #include <linux/psci.h>
>>   #include <linux/reboot.h>
>> +#include <linux/suspend.h>
>>
>>   #include <uapi/linux/psci.h>
>>
>>   #include <asm/system_misc.h>
>>   #include <asm/smp_plat.h>
>> +#include <asm/suspend.h>
>>
>>   /*
>>    * While a 64-bit OS can make calls with SMC32 calling conventions, for some
>> @@ -222,6 +224,41 @@ static int __init psci_features(u32 psci_func_id)
>>   			      psci_func_id, 0, 0);
>>   }
>>
>> +static int psci_system_suspend(unsigned long entry_point)
>> +{
>> +	return invoke_psci_fn(PSCI_0_2_FN_NATIVE(SYSTEM_SUSPEND),
>> +			      entry_point, 0, 0);
>> +}
>> +
>> +static int psci_system_suspend_finisher(unsigned long unused)
>> +{
>> +	return psci_system_suspend(virt_to_phys(cpu_resume));
>
> Do we really need another level of indirection ? I would invoke
> the PSCI function from here.
>

True not really required, copied from other functions just for
consistency. I will merge them into one.

>> +}
>> +
>> +static int psci_system_suspend_enter(suspend_state_t state)
>> +{
>> +	if (state != PM_SUSPEND_MEM)
>> +		return 0;
>
> suspend_valid_only_mem should check this, am I missing something ?
>

Yes it's taken care, I can remove that.

[...]

>> diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
>> index 2598d7c9bf20..62b054524819 100644
>> --- a/include/uapi/linux/psci.h
>> +++ b/include/uapi/linux/psci.h
>> @@ -39,12 +39,14 @@
>>   #define PSCI_0_2_FN_MIGRATE_INFO_UP_CPU		PSCI_0_2_FN(7)
>>   #define PSCI_0_2_FN_SYSTEM_OFF			PSCI_0_2_FN(8)
>>   #define PSCI_0_2_FN_SYSTEM_RESET		PSCI_0_2_FN(9)
>> +#define PSCI_0_2_FN_SYSTEM_SUSPEND		PSCI_0_2_FN(14)
>
> I think you should keep versioning consistent, namely SYSTEM_SUSPEND
> is a 1.0 only feature and the tag should reflect that.
>

Correct, IIRC I kept it to make you use of PSCI_0_2_FN_NATIVE initially
and forgot to change. I will update them all to use _1_0 tag.

Regards,
Sudeep
diff mbox

Patch

diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c
index 68d0c2f6d004..4f0359516119 100644
--- a/drivers/firmware/psci.c
+++ b/drivers/firmware/psci.c
@@ -20,11 +20,13 @@ 
 #include <linux/printk.h>
 #include <linux/psci.h>
 #include <linux/reboot.h>
+#include <linux/suspend.h>
 
 #include <uapi/linux/psci.h>
 
 #include <asm/system_misc.h>
 #include <asm/smp_plat.h>
+#include <asm/suspend.h>
 
 /*
  * While a 64-bit OS can make calls with SMC32 calling conventions, for some
@@ -222,6 +224,41 @@  static int __init psci_features(u32 psci_func_id)
 			      psci_func_id, 0, 0);
 }
 
+static int psci_system_suspend(unsigned long entry_point)
+{
+	return invoke_psci_fn(PSCI_0_2_FN_NATIVE(SYSTEM_SUSPEND),
+			      entry_point, 0, 0);
+}
+
+static int psci_system_suspend_finisher(unsigned long unused)
+{
+	return psci_system_suspend(virt_to_phys(cpu_resume));
+}
+
+static int psci_system_suspend_enter(suspend_state_t state)
+{
+	if (state != PM_SUSPEND_MEM)
+		return 0;
+
+	return cpu_suspend(0, psci_system_suspend_finisher);
+}
+
+static const struct platform_suspend_ops psci_suspend_ops = {
+	.valid          = suspend_valid_only_mem,
+	.enter          = psci_system_suspend_enter,
+};
+
+static void __init psci_init_system_suspend(void)
+{
+	if (!IS_ENABLED(CONFIG_SUSPEND))
+		return;
+
+	if (psci_features(PSCI_0_2_FN_NATIVE(SYSTEM_SUSPEND)))
+		return;
+
+	suspend_set_ops(&psci_suspend_ops);
+}
+
 static void __init psci_init_cpu_suspend(void)
 {
 	int feature = psci_features(psci_function_id[PSCI_FN_CPU_SUSPEND]);
@@ -310,6 +347,8 @@  static int __init psci_probe(void)
 
 	psci_init_cpu_suspend();
 
+	psci_init_system_suspend();
+
 	return 0;
 }
 
diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
index 2598d7c9bf20..62b054524819 100644
--- a/include/uapi/linux/psci.h
+++ b/include/uapi/linux/psci.h
@@ -39,12 +39,14 @@ 
 #define PSCI_0_2_FN_MIGRATE_INFO_UP_CPU		PSCI_0_2_FN(7)
 #define PSCI_0_2_FN_SYSTEM_OFF			PSCI_0_2_FN(8)
 #define PSCI_0_2_FN_SYSTEM_RESET		PSCI_0_2_FN(9)
+#define PSCI_0_2_FN_SYSTEM_SUSPEND		PSCI_0_2_FN(14)
 
 #define PSCI_0_2_FN64_CPU_SUSPEND		PSCI_0_2_FN64(1)
 #define PSCI_0_2_FN64_CPU_ON			PSCI_0_2_FN64(3)
 #define PSCI_0_2_FN64_AFFINITY_INFO		PSCI_0_2_FN64(4)
 #define PSCI_0_2_FN64_MIGRATE			PSCI_0_2_FN64(5)
 #define PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU	PSCI_0_2_FN64(7)
+#define PSCI_0_2_FN64_SYSTEM_SUSPEND		PSCI_0_2_FN64(14)
 
 #define PSCI_1_0_FN_PSCI_FEATURES		PSCI_0_2_FN(10)