[resend PATCH 2/5] libata: export ata_port suspend/resume infrastructure for sas
From: Dan Williams <hidden>
Date: 2012-07-10 04:05:52
Also in:
linux-scsi
Subsystem:
libata subsystem (serial and parallel ata drivers), the rest · Maintainers:
Damien Le Moal, Niklas Cassel, Linus Torvalds
Reuse ata_port_{suspend|resume}_common for sas. This path is chosen
over adding coordination between ata-tranport and sas-transport because
libsas wants to revalidate the domain at resume-time at the host level.
It can not validate links have resumed properly until libata has had a
chance to perform its revalidation, and any sane placing of an ata_port
in the sas-transport model would delay it's resumption until after the
host.
Export the common portion of port suspend/resume (bypass pm_runtime),
and allow sas to perform these operations asynchronously (similar to the
libsas async-ata probe implmentation). Async operation is determined by
having an external, rather than stack based, location for storing the
result of the operation.
Reviewed-by: Jacek Danecki <redacted>
Signed-off-by: Dan Williams <redacted>
---
drivers/ata/libata-core.c | 58 ++++++++++++++++++++++++++++++++++++---------
include/linux/libata.h | 11 +++++++++
2 files changed, 57 insertions(+), 12 deletions(-)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index efd2c72..da31691 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c@@ -5248,16 +5248,20 @@ bool ata_link_offline(struct ata_link *link) #ifdef CONFIG_PM static int ata_port_request_pm(struct ata_port *ap, pm_message_t mesg, unsigned int action, unsigned int ehi_flags, - int wait) + int *async) { struct ata_link *link; unsigned long flags; - int rc; + int rc = 0; /* Previous resume operation might still be in * progress. Wait for PM_PENDING to clear. */ if (ap->pflags & ATA_PFLAG_PM_PENDING) { + if (async) { + *async = -EAGAIN; + return 0; + } ata_port_wait_eh(ap); WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING); }
@@ -5266,10 +5270,10 @@ static int ata_port_request_pm(struct ata_port *ap, pm_message_t mesg, spin_lock_irqsave(ap->lock, flags); ap->pm_mesg = mesg; - if (wait) { - rc = 0; + if (async) + ap->pm_result = async; + else ap->pm_result = &rc; - } ap->pflags |= ATA_PFLAG_PM_PENDING; ata_for_each_link(link, ap, HOST_FIRST) {
@@ -5282,7 +5286,7 @@ static int ata_port_request_pm(struct ata_port *ap, pm_message_t mesg, spin_unlock_irqrestore(ap->lock, flags); /* wait and check result */ - if (wait) { + if (!async) { ata_port_wait_eh(ap); WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING); }
@@ -5292,9 +5296,8 @@ static int ata_port_request_pm(struct ata_port *ap, pm_message_t mesg, #define to_ata_port(d) container_of(d, struct ata_port, tdev) -static int ata_port_suspend_common(struct device *dev, pm_message_t mesg) +static int __ata_port_suspend_common(struct ata_port *ap, pm_message_t mesg, int *async) { - struct ata_port *ap = to_ata_port(dev); unsigned int ehi_flags = ATA_EHI_QUIET; int rc;
@@ -5309,10 +5312,17 @@ static int ata_port_suspend_common(struct device *dev, pm_message_t mesg) if (mesg.event == PM_EVENT_SUSPEND) ehi_flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_NO_RECOVERY; - rc = ata_port_request_pm(ap, mesg, 0, ehi_flags, 1); + rc = ata_port_request_pm(ap, mesg, 0, ehi_flags, async); return rc; } +static int ata_port_suspend_common(struct device *dev, pm_message_t mesg) +{ + struct ata_port *ap = to_ata_port(dev); + + return __ata_port_suspend_common(ap, mesg, NULL); +} + static int ata_port_suspend(struct device *dev) { if (pm_runtime_suspended(dev))
@@ -5337,16 +5347,22 @@ static int ata_port_poweroff(struct device *dev) return ata_port_suspend_common(dev, PMSG_HIBERNATE); } -static int ata_port_resume_common(struct device *dev) +static int __ata_port_resume_common(struct ata_port *ap, int *async) { - struct ata_port *ap = to_ata_port(dev); int rc; rc = ata_port_request_pm(ap, PMSG_ON, ATA_EH_RESET, - ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET, 1); + ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET, async); return rc; } +static int ata_port_resume_common(struct device *dev) +{ + struct ata_port *ap = to_ata_port(dev); + + return __ata_port_resume_common(ap, NULL); +} + static int ata_port_resume(struct device *dev) { int rc;
@@ -5379,6 +5395,24 @@ static const struct dev_pm_ops ata_port_pm_ops = { .runtime_idle = ata_port_runtime_idle, }; +/* sas ports don't participate in pm runtime management of ata_ports, + * and need to resume ata devices at the domain level, not the per-port + * level. sas suspend/resume is async to allow parallel port recovery + * since sas has multiple ata_port instances per Scsi_Host. + */ +int ata_sas_port_async_suspend(struct ata_port *ap, int *async) +{ + return __ata_port_suspend_common(ap, PMSG_SUSPEND, async); +} +EXPORT_SYMBOL_GPL(ata_sas_port_async_suspend); + +int ata_sas_port_async_resume(struct ata_port *ap, int *async) +{ + return __ata_port_resume_common(ap, async); +} +EXPORT_SYMBOL_GPL(ata_sas_port_async_resume); + + /** * ata_host_suspend - suspend host * @host: host to suspend
diff --git a/include/linux/libata.h b/include/linux/libata.h
index f777d30..af467d3 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h@@ -1016,6 +1016,17 @@ extern bool ata_link_offline(struct ata_link *link); #ifdef CONFIG_PM extern int ata_host_suspend(struct ata_host *host, pm_message_t mesg); extern void ata_host_resume(struct ata_host *host); +extern int ata_sas_port_async_suspend(struct ata_port *ap, int *async); +extern int ata_sas_port_async_resume(struct ata_port *ap, int *async); +#else +static inline int ata_sas_port_async_suspend(struct ata_port *ap, int *async) +{ + return 0; +} +static inline int ata_sas_port_async_resume(struct ata_port *ap, int *async) +{ + return 0; +} #endif extern int ata_ratelimit(void); extern void ata_msleep(struct ata_port *ap, unsigned int msecs);