diff options
| -rw-r--r-- | drivers/s390/cio/Makefile | 2 | ||||
| -rw-r--r-- | drivers/s390/cio/ccwreq.c | 327 | ||||
| -rw-r--r-- | drivers/s390/cio/device.h | 8 | ||||
| -rw-r--r-- | drivers/s390/cio/io_sch.h | 50 |
4 files changed, 386 insertions, 1 deletions
diff --git a/drivers/s390/cio/Makefile b/drivers/s390/cio/Makefile index fa4c9662f65..d033414f759 100644 --- a/drivers/s390/cio/Makefile +++ b/drivers/s390/cio/Makefile @@ -3,7 +3,7 @@ # obj-y += airq.o blacklist.o chsc.o cio.o css.o chp.o idset.o isc.o \ - fcx.o itcw.o crw.o + fcx.o itcw.o crw.o ccwreq.o ccw_device-objs += device.o device_fsm.o device_ops.o ccw_device-objs += device_id.o device_pgid.o device_status.o obj-y += ccw_device.o cmf.o diff --git a/drivers/s390/cio/ccwreq.c b/drivers/s390/cio/ccwreq.c new file mode 100644 index 00000000000..a6e205a384b --- /dev/null +++ b/drivers/s390/cio/ccwreq.c @@ -0,0 +1,327 @@ +/* + * Handling of internal CCW device requests. + * + * Copyright IBM Corp. 2009 + * Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com> + */ + +#include <linux/types.h> +#include <linux/err.h> +#include <asm/ccwdev.h> +#include <asm/cio.h> + +#include "io_sch.h" +#include "cio.h" +#include "device.h" +#include "cio_debug.h" + +/** + * lpm_adjust - adjust path mask + * @lpm: path mask to adjust + * @mask: mask of available paths + * + * Shift @lpm right until @lpm and @mask have at least one bit in common or + * until @lpm is zero. Return the resulting lpm. + */ +int lpm_adjust(int lpm, int mask) +{ + while (lpm && ((lpm & mask) == 0)) + lpm >>= 1; + return lpm; +} + +/* + * Adjust path mask to use next path and reset retry count. Return resulting + * path mask. + */ +static u16 ccwreq_next_path(struct ccw_device *cdev) +{ + struct ccw_request *req = &cdev->private->req; + + req->retries = req->maxretries; + req->mask = lpm_adjust(req->mask >>= 1, req->lpm); + + return req->mask; +} + +/* + * Clean up device state and report to callback. + */ +static void ccwreq_stop(struct ccw_device *cdev, int rc) +{ + struct subchannel *sch = to_subchannel(cdev->dev.parent); + struct ccw_request *req = &cdev->private->req; + + if (req->done) + return; + req->done = 1; + ccw_device_set_timeout(cdev, 0); + memset(&cdev->private->irb, 0, sizeof(struct irb)); + sch->lpm = sch->schib.pmcw.pam; + if (rc && rc != -ENODEV && req->drc) + rc = req->drc; + req->callback(cdev, req->data, rc); +} + +/* + * (Re-)Start the operation until retries and paths are exhausted. + */ +static void ccwreq_do(struct ccw_device *cdev) +{ + struct ccw_request *req = &cdev->private->req; + struct subchannel *sch = to_subchannel(cdev->dev.parent); + struct ccw1 *cp = req->cp; + int rc = -EACCES; + + while (req->mask) { + if (req->retries-- == 0) { + /* Retries exhausted, try next path. */ + ccwreq_next_path(cdev); + continue; + } + /* Perform start function. */ + sch->lpm = 0xff; + memset(&cdev->private->irb, 0, sizeof(struct irb)); + rc = cio_start(sch, cp, req->mask); + if (rc == 0) { + /* I/O started successfully. */ + ccw_device_set_timeout(cdev, req->timeout); + return; + } + if (rc == -ENODEV) { + /* Permanent device error. */ + break; + } + if (rc == -EACCES) { + /* Permant path error. */ + ccwreq_next_path(cdev); + continue; + } + /* Temporary improper status. */ + rc = cio_clear(sch); + if (rc) + break; + return; + } + ccwreq_stop(cdev, rc); +} + +/** + * ccw_request_start - perform I/O request + * @cdev: ccw device + * + * Perform the I/O request specified by cdev->req. + */ +void ccw_request_start(struct ccw_device *cdev) +{ + struct ccw_request *req = &cdev->private->req; + + req->mask = 0x80; + req->retries = req->maxretries; + req->mask = lpm_adjust(req->mask, req->lpm); + req->drc = 0; + req->done = 0; + req->cancel = 0; + if (!req->mask) + goto out_nopath; + ccwreq_do(cdev); + return; + +out_nopath: + ccwreq_stop(cdev, -EACCES); +} + +/** + * ccw_request_cancel - cancel running I/O request + * @cdev: ccw device + * + * Cancel the I/O request specified by cdev->req. Return non-zero if request + * has already finished, zero otherwise. + */ +int ccw_request_cancel(struct ccw_device *cdev) +{ + struct subchannel *sch = to_subchannel(cdev->dev.parent); + struct ccw_request *req = &cdev->private->req; + int rc; + + if (req->done) + return 1; + req->cancel = 1; + rc = cio_clear(sch); + if (rc) + ccwreq_stop(cdev, rc); + return 0; +} + +/* + * Return the status of the internal I/O started on the specified ccw device. + * Perform BASIC SENSE if required. + */ +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; + + /* Perform BASIC SENSE if needed. */ + if (ccw_device_accumulate_and_sense(cdev, lcirb)) + return IO_RUNNING; + /* Check for halt/clear interrupt. */ + if (scsw->fctl & (SCSW_FCTL_HALT_FUNC | SCSW_FCTL_CLEAR_FUNC)) + return IO_KILLED; + /* Check for path error. */ + if (scsw->cc == 3 || scsw->pno) + return IO_PATH_ERROR; + /* Handle BASIC SENSE data. */ + if (irb->esw.esw0.erw.cons) { + CIO_TRACE_EVENT(2, "sensedata"); + CIO_HEX_EVENT(2, &cdev->private->dev_id, + sizeof(struct ccw_dev_id)); + CIO_HEX_EVENT(2, &cdev->private->irb.ecw, SENSE_MAX_COUNT); + /* Check for command reject. */ + if (irb->ecw[0] & SNS0_CMD_REJECT) + return IO_REJECTED; + /* Assume that unexpected SENSE data implies an error. */ + return IO_STATUS_ERROR; + } + /* Check for channel errors. */ + if (scsw->cstat != 0) + return IO_STATUS_ERROR; + /* Check for device errors. */ + if (scsw->dstat & ~(DEV_STAT_CHN_END | DEV_STAT_DEV_END)) + return IO_STATUS_ERROR; + /* Check for final state. */ + if (!(scsw->dstat & DEV_STAT_DEV_END)) + return IO_RUNNING; + /* Check for other improper status. */ + if (scsw->cc == 1 && (scsw->stctl & SCSW_STCTL_ALERT_STATUS)) + return IO_STATUS_ERROR; + return IO_DONE; +} + +/* + * Log ccw request status. + */ +static void ccwreq_log_status(struct ccw_device *cdev, enum io_status status) +{ + struct ccw_request *req = &cdev->private->req; + struct { + struct ccw_dev_id dev_id; + u16 retries; + u8 lpm; + u8 status; + } __attribute__ ((packed)) data; + data.dev_id = cdev->private->dev_id; + data.retries = req->retries; + data.lpm = req->mask; + data.status = (u8) status; + CIO_TRACE_EVENT(2, "reqstat"); + CIO_HEX_EVENT(2, &data, sizeof(data)); +} + +/** + * ccw_request_handler - interrupt handler for I/O request procedure. + * @cdev: ccw device + * + * Handle interrupt during I/O request procedure. + */ +void ccw_request_handler(struct ccw_device *cdev) +{ + struct ccw_request *req = &cdev->private->req; + struct irb *irb = (struct irb *) __LC_IRB; + enum io_status status; + int rc = -EOPNOTSUPP; + + /* Check status of I/O request. */ + status = ccwreq_status(cdev, irb); + if (req->filter) + status = req->filter(cdev, req->data, irb, status); + if (status != IO_RUNNING) + ccw_device_set_timeout(cdev, 0); + if (status != IO_DONE && status != IO_RUNNING) + ccwreq_log_status(cdev, status); + switch (status) { + case IO_DONE: + break; + case IO_RUNNING: + return; + case IO_REJECTED: + goto err; + case IO_PATH_ERROR: + goto out_next_path; + case IO_STATUS_ERROR: + goto out_restart; + case IO_KILLED: + /* Check if request was cancelled on purpose. */ + if (req->cancel) { + rc = -EIO; + goto err; + } + goto out_restart; + } + /* Check back with request initiator. */ + if (!req->check) + goto out; + switch (req->check(cdev, req->data)) { + case 0: + break; + case -EAGAIN: + goto out_restart; + case -EACCES: + goto out_next_path; + default: + goto err; + } +out: + ccwreq_stop(cdev, 0); + return; + +out_next_path: + /* Try next path and restart I/O. */ + if (!ccwreq_next_path(cdev)) { + rc = -EACCES; + goto err; + } +out_restart: + /* Restart. */ + ccwreq_do(cdev); + return; +err: + ccwreq_stop(cdev, rc); +} + + +/** + * ccw_request_timeout - timeout handler for I/O request procedure + * @cdev: ccw device + * + * Handle timeout during I/O request procedure. + */ +void ccw_request_timeout(struct ccw_device *cdev) +{ + struct subchannel *sch = to_subchannel(cdev->dev.parent); + struct ccw_request *req = &cdev->private->req; + int rc; + + if (!ccwreq_next_path(cdev)) { + /* set the final return code for this request */ + req->drc = -ETIME; + } + rc = cio_clear(sch); + if (rc) + goto err; + return; + +err: + ccwreq_stop(cdev, rc); +} + +/** + * ccw_request_notoper - notoper handler for I/O request procedure + * @cdev: ccw device + * + * Handle timeout during I/O request procedure. + */ +void ccw_request_notoper(struct ccw_device *cdev) +{ + ccwreq_stop(cdev, -ENODEV); +} diff --git a/drivers/s390/cio/device.h b/drivers/s390/cio/device.h index 78662e05d31..f3c8a2a8c3a 100644 --- a/drivers/s390/cio/device.h +++ b/drivers/s390/cio/device.h @@ -98,6 +98,14 @@ void ccw_device_accumulate_basic_sense(struct ccw_device *, struct irb *); int ccw_device_accumulate_and_sense(struct ccw_device *, struct irb *); int ccw_device_do_sense(struct ccw_device *, struct irb *); +/* Function prototype for internal request handling. */ +int lpm_adjust(int lpm, int mask); +void ccw_request_start(struct ccw_device *); +int ccw_request_cancel(struct ccw_device *cdev); +void ccw_request_handler(struct ccw_device *cdev); +void ccw_request_timeout(struct ccw_device *cdev); +void ccw_request_notoper(struct ccw_device *cdev); + /* Function prototypes for sense id stuff. */ void ccw_device_sense_id_start(struct ccw_device *); void ccw_device_sense_id_irq(struct ccw_device *, enum dev_event); diff --git a/drivers/s390/cio/io_sch.h b/drivers/s390/cio/io_sch.h index b770e420213..f9ff7683e24 100644 --- a/drivers/s390/cio/io_sch.h +++ b/drivers/s390/cio/io_sch.h @@ -1,7 +1,10 @@ #ifndef S390_IO_SCH_H #define S390_IO_SCH_H +#include <linux/types.h> #include <asm/schid.h> +#include <asm/ccwdev.h> +#include "css.h" /* * command-mode operation request block @@ -68,6 +71,52 @@ struct io_subchannel_private { #define MAX_CIWS 8 /* + * Possible status values for a CCW request's I/O. + */ +enum io_status { + IO_DONE, + IO_RUNNING, + IO_STATUS_ERROR, + IO_PATH_ERROR, + IO_REJECTED, + IO_KILLED +}; + +/** + * ccw_request - Internal CCW request. + * @cp: channel program to start + * @timeout: maximum allowable time in jiffies between start I/O and interrupt + * @maxretries: number of retries per I/O operation and path + * @lpm: mask of paths to use + * @check: optional callback that determines if results are final + * @filter: optional callback to adjust request status based on IRB data + * @callback: final callback + * @data: user-defined pointer passed to all callbacks + * @mask: current path mask + * @retries: current number of retries + * @drc: delayed return code + * @cancel: non-zero if request was cancelled + * @done: non-zero if request was finished + */ +struct ccw_request { + struct ccw1 *cp; + unsigned long timeout; + u16 maxretries; + u8 lpm; + int (*check)(struct ccw_device *, void *); + enum io_status (*filter)(struct ccw_device *, void *, struct irb *, + enum io_status); + void (*callback)(struct ccw_device *, void *, int); + void *data; + /* These fields are used internally. */ + u8 mask; + u16 retries; + int drc; + int cancel:1; + int done:1; +} __attribute__((packed)); + +/* * sense-id response buffer layout */ struct senseid { @@ -99,6 +148,7 @@ struct ccw_device_private { unsigned long registered; struct ccw_dev_id dev_id; /* device id */ struct subchannel_id schid; /* subchannel number */ + struct ccw_request req; /* internal I/O request */ u8 imask; /* lpm mask for SNID/SID/SPGID */ int iretry; /* retry counter SNID/SID/SPGID */ struct { |