Subject: Re: [PATCH v5] powerpc/powernv: Add poweroff (EPOW, DPO) events support for PowerNV platform

From: Vipin K Parashar <[email-masked]>
Date: Tue, 02 Jun 2015 10:50:44 +0530

Hi Michael,
              Please add below minor additions in commit log once u
accept this patch. Thanks for your help with this. Let me know,
if anything else is needed from me on this.

Regards,
Vipin

On 05/18/2015 08:48 PM, Vipin K Parashar wrote:
> This patch adds support for FSP EPOW (Early Power Off Warning) and
> DPO (Delayed Power Off) events for PowerNV platform. EPOW events are
> generated by SPCN/FSP due to various critical system conditions that
> need system shutdown. Few examples of these conditions are high
> ambient temperature or system running on UPS power with low UPS battery.
> DPO event is generated in response to admin initiated system request.

s/system request/shutdown request/

> 	Upon receipt of EPOW and DPO events host kernel invokes
> orderly_poweroff for performing graceful system shutdown. System admin
> can also add systemd service shutdown scripts to perform any specific
> actions like graceful guest shutdown upon system poweroff. libvirt-guests
> is systemd service available on recent distros for management of guests
> at system start/shutdown time.
>
> Signed-off-by: Vipin K Parashar <[email-masked]>

Reviewed-by: Joel Stanley <[email-masked]>
Reviewed-by: Vaibhav Jain <[email-masked]>

> ---
>   arch/powerpc/include/asm/opal-api.h            |  44 ++++++++
>   arch/powerpc/include/asm/opal.h                |   3 +-
>   arch/powerpc/platforms/powernv/opal-power.c    | 147 ++++++++++++++++++++++---
>   arch/powerpc/platforms/powernv/opal-wrappers.S |   1 +
>   4 files changed, 179 insertions(+), 16 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
> index 0321a90..90fa364 100644
> --- a/arch/powerpc/include/asm/opal-api.h
> +++ b/arch/powerpc/include/asm/opal-api.h
> @@ -355,6 +355,10 @@ enum opal_msg_type {
>   	OPAL_MSG_TYPE_MAX,
>   };
>
> +/* OPAL_MSG_SHUTDOWN parameter values */
> +#define	SOFT_OFF	0x00
> +#define	SOFT_REBOOT	0x01
> +
>   struct opal_msg {
>   	__be32 msg_type;
>   	__be32 reserved;
> @@ -730,6 +734,46 @@ struct opal_i2c_request {
>   	__be64 buffer_ra;		/* Buffer real address */
>   };
>
> +/*
> + * EPOW status sharing (OPAL and the host)
> + *
> + * The host will pass on OPAL, a buffer of length OPAL_SYSEPOW_MAX
> + * with individual elements being 16 bits wide to fetch the system
> + * wide EPOW status. Each element in the buffer will contain the
> + * EPOW status in it's bit representation for a particular EPOW sub
> + * class as defiend here. So multiple detailed EPOW status bits
> + * specific for any sub class can be represented in a single buffer
> + * element as it's bit representation.
> + */
> +
> +/* System EPOW type */
> +enum OpalSysEpow {
> +	OPAL_SYSEPOW_POWER	= 0,	/* Power EPOW */
> +	OPAL_SYSEPOW_TEMP	= 1,	/* Temperature EPOW */
> +	OPAL_SYSEPOW_COOLING	= 2,	/* Cooling EPOW */
> +	OPAL_SYSEPOW_MAX	= 3,	/* Max EPOW categories */
> +};
> +
> +/* Power EPOW */
> +enum OpalSysPower {
> +	OPAL_SYSPOWER_UPS	= 0x0001, /* System on UPS power */
> +	OPAL_SYSPOWER_CHNG	= 0x0002, /* System power config change */
> +	OPAL_SYSPOWER_FAIL	= 0x0004, /* System impending power failure */
> +	OPAL_SYSPOWER_INCL	= 0x0008, /* System incomplete power */
> +};
> +
> +/* Temperature EPOW */
> +enum OpalSysTemp {
> +	OPAL_SYSTEMP_AMB	= 0x0001, /* System over ambient temperature */
> +	OPAL_SYSTEMP_INT	= 0x0002, /* System over internal temperature */
> +	OPAL_SYSTEMP_HMD	= 0x0004, /* System over ambient humidity */
> +};
> +
> +/* Cooling EPOW */
> +enum OpalSysCooling {
> +	OPAL_SYSCOOL_INSF	= 0x0001, /* System insufficient cooling */
> +};
> +
>   #endif /* __ASSEMBLY__ */
>
>   #endif /* __OPAL_API_H */
> diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
> index 042af1a..d30766f 100644
> --- a/arch/powerpc/include/asm/opal.h
> +++ b/arch/powerpc/include/asm/opal.h
> @@ -141,7 +141,8 @@ int64_t opal_pci_fence_phb(uint64_t phb_id);
>   int64_t opal_pci_reinit(uint64_t phb_id, uint64_t reinit_scope, uint64_t data);
>   int64_t opal_pci_mask_pe_error(uint64_t phb_id, uint16_t pe_number, uint8_t error_type, uint8_t mask_action);
>   int64_t opal_set_slot_led_status(uint64_t phb_id, uint64_t slot_id, uint8_t led_type, uint8_t led_action);
> -int64_t opal_get_epow_status(__be64 *status);
> +int64_t opal_get_epow_status(uint16_t *status, uint16_t *length);
> +int64_t opal_get_dpo_status(int64_t *dpo_timeout);
>   int64_t opal_set_system_attention_led(uint8_t led_action);
>   int64_t opal_pci_next_error(uint64_t phb_id, __be64 *first_frozen_pe,
>   			    __be16 *pci_error_type, __be16 *severity);
> diff --git a/arch/powerpc/platforms/powernv/opal-power.c b/arch/powerpc/platforms/powernv/opal-power.c
> index ac46c2c..581bbd8 100644
> --- a/arch/powerpc/platforms/powernv/opal-power.c
> +++ b/arch/powerpc/platforms/powernv/opal-power.c
> @@ -1,5 +1,5 @@
>   /*
> - * PowerNV OPAL power control for graceful shutdown handling
> + * PowerNV support for OPAL power-control, poweroff events
>    *
>    * Copyright 2015 IBM Corp.
>    *
> @@ -9,18 +9,87 @@
>    * 2 of the License, or (at your option) any later version.
>    */
>
> +#define pr_fmt(fmt)	"OPAL-POWER: "	fmt
> +
>   #include <linux/kernel.h>
> +#include <linux/spinlock.h>
> +#include <linux/timer.h>
>   #include <linux/reboot.h>
> -#include <linux/notifier.h>
> -
> +#include <linux/of.h>
>   #include <asm/opal.h>
>   #include <asm/machdep.h>
>
> -#define SOFT_OFF 0x00
> -#define SOFT_REBOOT 0x01
> +/* Get EPOW status */
> +static bool get_epow_status(void)
> +{
> +	int i;
> +	u16 num_classes;
> +	__be16 epow_classes;
> +	__be16 opal_epow_status[OPAL_SYSEPOW_MAX] = {0};
> +
> +	/* Send kernel EPOW classes supported info to OPAL */
> +	epow_classes = cpu_to_be16(OPAL_SYSEPOW_MAX);
> +
> +	/* Get EPOW events information from OPAL */
> +	opal_get_epow_status(opal_epow_status, &epow_classes);
> +
> +	/* Look for EPOW events present */
> +	num_classes = be16_to_cpu(epow_classes);
> +	for (i = 0; i < num_classes; i++) {
> +		if (be16_to_cpu(opal_epow_status[i]))
> +			return true;
> +	}
> +
> +	return false;
> +}
> +
> +/* Process existing EPOW, DPO events */
> +static void process_existing_poweroff_events(void)
> +{
> +	int rc;
> +	__be64 opal_dpo_timeout;
>
> +	/* Check for DPO event */
> +	rc = opal_get_dpo_status(&opal_dpo_timeout);
> +	if (rc != OPAL_WRONG_STATE) {
> +		pr_info("Existing DPO event detected. Powering off system\n");
> +		goto poweroff;
> +	}
> +
> +	/* Check for EPOW event */
> +	if (get_epow_status()) {
> +		pr_info("Existing EPOW event detected. Powering off system");
> +		goto poweroff;
> +	}
> +	return;
> +
> +poweroff:
> +	orderly_poweroff(true);
> +}
> +
> +/* OPAL EPOW, DPO event notifier */
> +static int opal_epow_dpo_event(struct notifier_block *nb,
> +				unsigned long msg_type, void *msg)
> +{
> +	switch (msg_type) {
> +	case OPAL_MSG_EPOW:
> +		pr_info("EPOW msg received. Powering off system\n");
> +		break;
> +	case OPAL_MSG_DPO:
> +		pr_info("DPO msg received. Powering off system\n");
> +		break;
> +	default:
> +		pr_err("Unknown message type %lu\n", msg_type);
> +		return 0;
> +	}
> +
> +	orderly_poweroff(true);
> +	return 0;
> +}
> +
> +/* OPAL power-control events notifier */
>   static int opal_power_control_event(struct notifier_block *nb,
> -				    unsigned long msg_type, void *msg)
> +					unsigned long msg_type, void *msg)
>   {
>   	struct opal_msg *power_msg = msg;
>   	uint64_t type;
> @@ -29,20 +98,35 @@ static int opal_power_control_event(struct notifier_block *nb,
>
>   	switch (type) {
>   	case SOFT_REBOOT:
> -		pr_info("OPAL: reboot requested\n");
> +		pr_info("Reboot requested\n");
>   		orderly_reboot();
>   		break;
>   	case SOFT_OFF:
> -		pr_info("OPAL: poweroff requested\n");
> +		pr_info("Poweroff requested\n");
>   		orderly_poweroff(true);
>   		break;
>   	default:
> -		pr_err("OPAL: power control type unexpected %016llx\n", type);
> +		pr_err("Unknown power-control type %llu\n", type);
>   	}
>
>   	return 0;
>   }
>
> +/* OPAL EPOW event notifier block */
> +static struct notifier_block opal_epow_nb = {
> +	.notifier_call	= opal_epow_dpo_event,
> +	.next		= NULL,
> +	.priority	= 0,
> +};
> +
> +/* OPAL DPO event notifier block */
> +static struct notifier_block opal_dpo_nb = {
> +	.notifier_call	= opal_epow_dpo_event,
> +	.next		= NULL,
> +	.priority	= 0,
> +};
> +
> +/* OPAL power-control event notifier block */
>   static struct notifier_block opal_power_control_nb = {
>   	.notifier_call	= opal_power_control_event,
>   	.next		= NULL,
> @@ -51,16 +135,49 @@ static struct notifier_block opal_power_control_nb = {
>
>   static int __init opal_power_control_init(void)
>   {
> -	int ret;
> +	int ret, epow_dpo_supported = 0;
> +	struct device_node *node_epow;
>
> +	/* Register OPAL power-control events notifier */
>   	ret = opal_message_notifier_register(OPAL_MSG_SHUTDOWN,
> -					     &opal_power_control_nb);
> -	if (ret) {
> -		pr_err("%s: Can't register OPAL event notifier (%d)\n",
> -				__func__, ret);
> -		return ret;
> +				&opal_power_control_nb);
> +	if (ret)
> +		pr_err("Power-control events notifier registration "
> +				"failed, ret = %d\n", ret);
> +
> +	/* Determine EPOW, DPO support in hardware. */
> +	node_epow = of_find_node_by_path("/ibm,opal/epow");
> +	if (node_epow) {
> +		epow_dpo_supported = of_device_is_compatible(node_epow,
> +				"ibm,opal-v3-epow");
> +		of_node_put(node_epow);
>   	}
>
> +	if (epow_dpo_supported)
> +		pr_info("OPAL EPOW, DPO support detected.\n");
> +	else
> +		return 0;
> +
> +	/* Register EPOW event notifier */
> +	ret = opal_message_notifier_register(OPAL_MSG_EPOW,
> +			&opal_epow_nb);
> +	if (ret)
> +		pr_err("EPOW event notifier registration failed, "
> +				"ret = %d\n", ret);
> +
> +	/* Register DPO event notifier */
> +	ret = opal_message_notifier_register(OPAL_MSG_DPO,
> +			&opal_dpo_nb);
> +	if (ret)
> +		pr_err("DPO event notifier registration failed, "
> +				"ret = %d\n", ret);
> +
> +	/* Check for any existing EPOW or DPO events. */
> +	process_existing_poweroff_events();
> +
> +	pr_info("Poweroff events support initialized\n");
> +
>   	return 0;
>   }
> +
>   machine_subsys_initcall(powernv, opal_power_control_init);
> diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
> index a7ade94..5d3c8e3 100644
> --- a/arch/powerpc/platforms/powernv/opal-wrappers.S
> +++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
> @@ -249,6 +249,7 @@ OPAL_CALL(opal_pci_reinit,			OPAL_PCI_REINIT);
>   OPAL_CALL(opal_pci_mask_pe_error,		OPAL_PCI_MASK_PE_ERROR);
>   OPAL_CALL(opal_set_slot_led_status,		OPAL_SET_SLOT_LED_STATUS);
>   OPAL_CALL(opal_get_epow_status,			OPAL_GET_EPOW_STATUS);
> +OPAL_CALL(opal_get_dpo_status,			OPAL_GET_DPO_STATUS);
>   OPAL_CALL(opal_set_system_attention_led,	OPAL_SET_SYSTEM_ATTENTION_LED);
>   OPAL_CALL(opal_pci_next_error,			OPAL_PCI_NEXT_ERROR);
>   OPAL_CALL(opal_pci_poll,			OPAL_PCI_POLL);