This patch implements hotplug by polling - hp-poll. It is used for
* hotplug event detection on controllers which don't provide PHY
status changed interrupt.
* hotplug event detection on disabled ports after reset failure.
libata used to leave such ports in frozen state to protect the
system from malfunctioning controller/device. With hp-poll, hotplug
events no such ports are watched safely by polling, such that
removing/replacing the malfunctioning device triggers EH retry on
the port.
There are three port ops for hp-poll - hp_poll_activate, hp_poll,
hp_poll_deactivate. Only hp_poll is mandatory for hp-poll to work.
This patch also implements SATA standard polling callbacks which poll
SError.N/X bits - sata_std_hp_poll_activate() and sata_std_hp_poll().
By default, hp-poll is enabled only on disabled ports. If a LLD
doesn't support hotplug interrupts but can poll for hotplug events, it
should indicate so by setting ATA_FLAG_HP_POLLING which tells libata
to turn on hp-poll by default.
Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
---
drivers/ata/libata-core.c | 79 +++++++++++++++++++++++++++++
drivers/ata/libata-eh.c | 123 ++++++++++++++++++++++++++++++++++++++++++++-
drivers/ata/libata.h | 2 +
include/linux/libata.h | 10 ++++
4 files changed, 211 insertions(+), 3 deletions(-)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index c127d6f..006ab12 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2909,6 +2909,76 @@ void ata_std_postreset(struct ata_port *
}
/**
+ * sata_std_hp_poll_activate - standard SATA hotplug polling activation
+ * @ap: the target ata_port
+ *
+ * Activate SATA std hotplug polling.
+ *
+ * LOCKING:
+ * Kernel thread context (may sleep).
+ */
+void sata_std_hp_poll_activate(struct ata_port *ap)
+{
+ u32 serror;
+
+ sata_scr_read(ap, SCR_ERROR, &serror);
+ serror &= SERR_PHYRDY_CHG | SERR_DEV_XCHG;
+ if (serror)
+ sata_scr_write(ap, SCR_ERROR, serror);
+
+ ap->hp_poll_data = 0;
+}
+
+/**
+ * sata_std_hp_poll - standard SATA hotplug polling callback
+ * @ap: the target ata_port
+ *
+ * Poll SError.N/X for hotplug event. Hotplug event is triggered
+ * only after PHY stays stable for at least one full polling
+ * interval after the first event detection.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host_set lock)
+ *
+ * RETURNS:
+ * 1 if hotplug event has occurred, 0 otherwise.
+ */
+int sata_std_hp_poll(struct ata_port *ap)
+{
+ unsigned long state = (unsigned long)ap->hp_poll_data;
+ u32 serror;
+ int rc = 0;
+
+ sata_scr_read(ap, SCR_ERROR, &serror);
+ serror &= SERR_PHYRDY_CHG | SERR_DEV_XCHG;
+
+ switch (state) {
+ case 0:
+ if (serror) {
+ /* PHY status could be bouncing crazy due to
+ * faulty controller or device. Don't fire
+ * hotplug event till hotplug event stays
+ * quiescent for one full polling interval.
+ */
+ sata_scr_write(ap, SCR_ERROR, serror);
+ state = 1;
+ }
+ break;
+
+ case 1:
+ if (!serror)
+ rc = 1;
+ else
+ sata_scr_write(ap, SCR_ERROR, serror);
+ break;
+ }
+
+ ap->hp_poll_data = (void *)state;
+
+ return rc;
+}
+
+/**
* ata_dev_same_device - Determine whether new ID matches configured device
* @dev: device to compare against
* @new_class: class of the new device
@@ -5437,6 +5507,7 @@ void ata_host_init(struct ata_host *host
host->dev = dev;
host->flags = flags;
host->ops = ops;
+ INIT_WORK(&host->hp_poll_task, ata_hp_poll_worker, host);
}
/**
@@ -5691,11 +5762,15 @@ void ata_port_detach(struct ata_port *ap
ata_port_wait_eh(ap);
- /* Flush hotplug task. The sequence is similar to
+ /* deactivate hotplug polling */
+ ata_hp_poll_deactivate(ap);
+
+ /* Flush hotplug tasks. The sequence is similar to
* ata_port_flush_task().
*/
flush_workqueue(ata_aux_wq);
cancel_delayed_work(&ap->hotplug_task);
+ cancel_delayed_work(&ap->host->hp_poll_task);
flush_workqueue(ata_aux_wq);
skip_eh:
@@ -6129,6 +6204,8 @@ EXPORT_SYMBOL_GPL(ata_std_prereset);
EXPORT_SYMBOL_GPL(ata_std_softreset);
EXPORT_SYMBOL_GPL(sata_std_hardreset);
EXPORT_SYMBOL_GPL(ata_std_postreset);
+EXPORT_SYMBOL_GPL(sata_std_hp_poll_activate);
+EXPORT_SYMBOL_GPL(sata_std_hp_poll);
EXPORT_SYMBOL_GPL(ata_dev_revalidate);
EXPORT_SYMBOL_GPL(ata_dev_classify);
EXPORT_SYMBOL_GPL(ata_dev_pair);
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 02b2b27..6787fbc 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -33,6 +33,7 @@
*/
#include <linux/kernel.h>
+#include <linux/module.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_eh.h>
@@ -44,10 +45,17 @@ #include <linux/libata.h>
#include "libata.h"
+static unsigned long hotplug_polling_interval = 2000;
+module_param(hotplug_polling_interval, ulong, 0644);
+MODULE_PARM_DESC(hotplug_polling_interval,
+ "Hotplug polling interval in milliseconds (default 2000)");
+
static void __ata_port_freeze(struct ata_port *ap);
static void ata_eh_finish(struct ata_port *ap);
static void ata_eh_handle_port_suspend(struct ata_port *ap);
static void ata_eh_handle_port_resume(struct ata_port *ap);
+static void ata_hp_poll_activate(struct ata_port *ap);
+
static void ata_ering_record(struct ata_ering *ering, int is_io,
unsigned int err_mask)
@@ -616,7 +624,10 @@ int ata_port_freeze(struct ata_port *ap)
* ata_eh_freeze_port - EH helper to freeze port
* @ap: ATA port to freeze
*
- * Freeze @ap.
+ * Freeze @ap. As the 'freeze' operation means 'shutdown event
+ * reporting', it is a perfect place to deactivate hp-poll. Note
+ * that ata_port_freeze() always invokes EH and eventually this
+ * function, so deactivating hp-poll in this function is enough.
*
* LOCKING:
* None.
@@ -628,6 +639,8 @@ void ata_eh_freeze_port(struct ata_port
if (!ap->ops->error_handler)
return;
+ ata_hp_poll_deactivate(ap);
+
spin_lock_irqsave(ap->lock, flags);
__ata_port_freeze(ap);
spin_unlock_irqrestore(ap->lock, flags);
@@ -637,7 +650,7 @@ void ata_eh_freeze_port(struct ata_port
* ata_port_thaw_port - EH helper to thaw port
* @ap: ATA port to thaw
*
- * Thaw frozen port @ap.
+ * Thaw frozen port @ap and activate hp-poll if necessary.
*
* LOCKING:
* None.
@@ -658,6 +671,9 @@ void ata_eh_thaw_port(struct ata_port *a
spin_unlock_irqrestore(ap->lock, flags);
+ if (ap->flags & ATA_FLAG_HP_POLLING)
+ ata_hp_poll_activate(ap);
+
DPRINTK("ata%u port thawed\n", ap->id);
}
@@ -2059,6 +2075,9 @@ static int ata_eh_recover(struct ata_por
out:
if (rc) {
+ /* recovery failed, activate hp-poll */
+ ata_hp_poll_activate(ap);
+
for (i = 0; i < ATA_MAX_DEVICES; i++)
ata_dev_disable(&ap->device[i]);
}
@@ -2247,3 +2266,103 @@ static void ata_eh_handle_port_resume(st
}
spin_unlock_irqrestore(ap->lock, flags);
}
+
+static unsigned long ata_hp_poll_delay(void)
+{
+ unsigned long interval, now;
+
+ /* Group polls to polling interval boundaries to allow cpu to
+ * go idle as much as possible.
+ */
+ interval = hotplug_polling_interval * HZ / 1000;
+ now = jiffies;
+ return roundup(now + 1, interval) - now;
+}
+
+/**
+ * ata_hp_poll_activate - activate hotplug polling
+ * @ap: host port to activate hotplug polling for
+ *
+ * Activate hotplug probing for @ap.
+ *
+ * LOCKING:
+ * Kernel thread context (may sleep).
+ */
+static void ata_hp_poll_activate(struct ata_port *ap)
+{
+ unsigned long flags;
+
+ if (!ap->ops->hp_poll || (ap->pflags & ATA_PFLAG_HP_POLL))
+ return;
+
+ if (ap->ops->hp_poll_activate)
+ ap->ops->hp_poll_activate(ap);
+
+ queue_delayed_work(ata_aux_wq, &ap->host->hp_poll_task,
+ ata_hp_poll_delay());
+ ap->hp_poll_data = 0;
+
+ spin_lock_irqsave(ap->lock, flags);
+ ap->pflags |= ATA_PFLAG_HP_POLL;
+ spin_unlock_irqrestore(ap->lock, flags);
+}
+
+/**
+ * ata_hp_poll_deactivate - deactivate hotplug polling
+ * @ap: host port to deactivate hotplug polling for
+ *
+ * Deactivate hotplug probing for @ap.
+ *
+ * LOCKING:
+ * Kernel thread context (may sleep).
+ */
+void ata_hp_poll_deactivate(struct ata_port *ap)
+{
+ unsigned long flags;
+
+ if (!(ap->pflags & ATA_PFLAG_HP_POLL))
+ return;
+
+ spin_lock_irqsave(ap->lock, flags);
+ ap->pflags &= ~ATA_PFLAG_HP_POLL;
+ spin_unlock_irqrestore(ap->lock, flags);
+
+ if (ap->ops->hp_poll_deactivate)
+ ap->ops->hp_poll_deactivate(ap);
+}
+
+void ata_hp_poll_worker(void *data)
+{
+ struct ata_host *host = data;
+ int i, nr_to_poll = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&host->lock, flags);
+
+ for (i = 0; i < host->n_ports; i++) {
+ struct ata_port *ap = host->ports[i];
+ int rc;
+
+ if (!(ap->pflags & ATA_PFLAG_HP_POLL))
+ continue;
+
+ /* Poll. Positive return value indicates hotplug
+ * event while negative indicates error condition.
+ */
+ rc = ap->ops->hp_poll(ap);
+ if (rc) {
+ if (rc > 0) {
+ ata_ehi_hotplugged(&ap->eh_info);
+ ata_port_freeze(ap);
+ }
+ ap->pflags &= ~ATA_PFLAG_HP_POLL;
+ } else
+ nr_to_poll++;
+ }
+
+ spin_unlock_irqrestore(&host->lock, flags);
+
+ if (nr_to_poll)
+ queue_delayed_work(ata_aux_wq, &host->hp_poll_task,
+ ata_hp_poll_delay());
+}
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index a5ecb71..017dc08 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -118,5 +118,7 @@ extern enum scsi_eh_timer_return ata_scs
extern void ata_scsi_error(struct Scsi_Host *host);
extern void ata_port_wait_eh(struct ata_port *ap);
extern void ata_qc_schedule_eh(struct ata_queued_cmd *qc);
+extern void ata_hp_poll_worker(void *data);
+extern void ata_hp_poll_deactivate(struct ata_port *ap);
#endif /* __LIBATA_H__ */
diff --git a/include/linux/libata.h b/include/linux/libata.h
index d0a7ad5..4fc74c4 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -175,6 +175,7 @@ enum {
ATA_FLAG_SKIP_D2H_BSY = (1 << 12), /* can't wait for the first D2H
* Register FIS clearing BSY */
ATA_FLAG_DEBUGMSG = (1 << 13),
+ ATA_FLAG_HP_POLLING = (1 << 14), /* hotplug by polling */
/* The following flag belongs to ap->pflags but is kept in
* ap->flags because it's referenced in many LLDs and will be
@@ -192,6 +193,7 @@ enum {
ATA_PFLAG_LOADING = (1 << 4), /* boot/loading probe */
ATA_PFLAG_UNLOADING = (1 << 5), /* module is unloading */
ATA_PFLAG_SCSI_HOTPLUG = (1 << 6), /* SCSI hotplug scheduled */
+ ATA_PFLAG_HP_POLL = (1 << 7), /* hp-poll active */
ATA_PFLAG_FLUSH_PORT_TASK = (1 << 16), /* flush port task */
ATA_PFLAG_SUSPENDED = (1 << 17), /* port is suspended (power) */
@@ -401,6 +403,7 @@ struct ata_host {
unsigned long flags;
int simplex_claimed; /* Keep seperate in case we
ever need to do this locked */
+ struct work_struct hp_poll_task;
struct ata_port *ports[0];
};
@@ -581,6 +584,7 @@ struct ata_port {
pm_message_t pm_mesg;
int *pm_result;
+ void *hp_poll_data;
void *private_data;
u8 sector_buf[ATA_SECT_SIZE]; /* owned by EH */
@@ -628,6 +632,10 @@ struct ata_port_operations {
void (*error_handler) (struct ata_port *ap);
void (*post_internal_cmd) (struct ata_queued_cmd *qc);
+ void (*hp_poll_activate) (struct ata_port *ap);
+ void (*hp_poll_deactivate) (struct ata_port *ap);
+ int (*hp_poll) (struct ata_port *ap);
+
irq_handler_t irq_handler;
void (*irq_clear) (struct ata_port *);
@@ -702,6 +710,8 @@ extern int ata_std_prereset(struct ata_p
extern int ata_std_softreset(struct ata_port *ap, unsigned int *classes);
extern int sata_std_hardreset(struct ata_port *ap, unsigned int *class);
extern void ata_std_postreset(struct ata_port *ap, unsigned int *classes);
+extern void sata_std_hp_poll_activate(struct ata_port *ap);
+extern int sata_std_hp_poll(struct ata_port *ap);
extern int ata_dev_revalidate(struct ata_device *dev, int post_reset);
extern void ata_port_disable(struct ata_port *);
extern void ata_std_ports(struct ata_ioports *ioaddr);
--
1.4.2.3
-
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
