From 094f2100d6bb16ef0c4f82167cc55173ca22ee93 Mon Sep 17 00:00:00 2001 From: Michael Ernst 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 Signed-off-by: Martin Schwidefsky --- 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; }