From 094f2100d6bb16ef0c4f82167cc55173ca22ee93 Mon Sep 17 00:00:00 2001
From: Michael Ernst <mernst@de.ibm.com>
Date: Wed, 26 May 2010 23:27:08 +0200
Subject: [PATCH] [S390] cio: unit check handling during internal I/O
Send unit checks that occur during internal I/O to the device driver
and react according to its return code.
Signed-off-by: Michael Ernst <mernst@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
arch/s390/include/asm/ccwdev.h | 10 ++++++++++
drivers/s390/cio/ccwreq.c | 15 +++++++++++++++
2 files changed, 25 insertions(+)
diff --git a/arch/s390/include/asm/ccwdev.h b/arch/s390/include/asm/ccwdev.h
index f4bd346a52d3..1c0030f9b890 100644
--- a/arch/s390/include/asm/ccwdev.h
+++ b/arch/s390/include/asm/ccwdev.h
@@ -91,6 +91,14 @@ struct ccw_device {
void (*handler) (struct ccw_device *, unsigned long, struct irb *);
};
+/*
+ * Possible CIO actions triggered by the unit check handler.
+ */
+enum uc_todo {
+ UC_TODO_RETRY,
+ UC_TODO_RETRY_ON_NEW_PATH,
+ UC_TODO_STOP
+};
/**
* struct ccw driver - device driver for channel attached devices
@@ -107,6 +115,7 @@ struct ccw_device {
* @freeze: callback for freezing during hibernation snapshotting
* @thaw: undo work done in @freeze
* @restore: callback for restoring after hibernation
+ * @uc_handler: callback for unit check handler
* @driver: embedded device driver structure
* @name: device driver name
*/
@@ -124,6 +133,7 @@ struct ccw_driver {
int (*freeze)(struct ccw_device *);
int (*thaw) (struct ccw_device *);
int (*restore)(struct ccw_device *);
+ enum uc_todo (*uc_handler) (struct ccw_device *, struct irb *);
struct device_driver driver;
char *name;
};
diff --git a/drivers/s390/cio/ccwreq.c b/drivers/s390/cio/ccwreq.c
index 37df42af05ec..7f206ed44fdf 100644
--- a/drivers/s390/cio/ccwreq.c
+++ b/drivers/s390/cio/ccwreq.c
@@ -159,6 +159,7 @@ static enum io_status ccwreq_status(struct ccw_device *cdev, struct irb *lcirb)
{
struct irb *irb = &cdev->private->irb;
struct cmd_scsw *scsw = &irb->scsw.cmd;
+ enum uc_todo todo;
/* Perform BASIC SENSE if needed. */
if (ccw_device_accumulate_and_sense(cdev, lcirb))
@@ -178,6 +179,20 @@ static enum io_status ccwreq_status(struct ccw_device *cdev, struct irb *lcirb)
/* Check for command reject. */
if (irb->ecw[0] & SNS0_CMD_REJECT)
return IO_REJECTED;
+ /* Ask the driver what to do */
+ if (cdev->drv && cdev->drv->uc_handler) {
+ todo = cdev->drv->uc_handler(cdev, lcirb);
+ switch (todo) {
+ case UC_TODO_RETRY:
+ return IO_STATUS_ERROR;
+ case UC_TODO_RETRY_ON_NEW_PATH:
+ return IO_PATH_ERROR;
+ case UC_TODO_STOP:
+ return IO_REJECTED;
+ default:
+ return IO_STATUS_ERROR;
+ }
+ }
/* Assume that unexpected SENSE data implies an error. */
return IO_STATUS_ERROR;
}
--
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