libata: add ata_ratelimit(), use it in AHCI driver irq handler
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index f0894bf..ceffaef 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -48,6 +48,7 @@
#include <linux/completion.h>
#include <linux/suspend.h>
#include <linux/workqueue.h>
+#include <linux/jiffies.h>
#include <scsi/scsi.h>
#include "scsi.h"
#include "scsi_priv.h"
@@ -4688,6 +4689,27 @@
module_init(ata_init);
module_exit(ata_exit);
+static unsigned long ratelimit_time;
+static spinlock_t ata_ratelimit_lock = SPIN_LOCK_UNLOCKED;
+
+int ata_ratelimit(void)
+{
+ int rc;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ata_ratelimit_lock, flags);
+
+ if (time_after(jiffies, ratelimit_time)) {
+ rc = 1;
+ ratelimit_time = jiffies + (HZ/5);
+ } else
+ rc = 0;
+
+ spin_unlock_irqrestore(&ata_ratelimit_lock, flags);
+
+ return rc;
+}
+
/*
* libata is essentially a library of internal helper functions for
* low-level ATA host controller drivers. As such, the API/ABI is
@@ -4729,6 +4751,7 @@
EXPORT_SYMBOL_GPL(__sata_phy_reset);
EXPORT_SYMBOL_GPL(ata_bus_reset);
EXPORT_SYMBOL_GPL(ata_port_disable);
+EXPORT_SYMBOL_GPL(ata_ratelimit);
EXPORT_SYMBOL_GPL(ata_scsi_ioctl);
EXPORT_SYMBOL_GPL(ata_scsi_queuecmd);
EXPORT_SYMBOL_GPL(ata_scsi_error);