From 196339f1733726ffd69ab81ec1c66678585f5846 Mon Sep 17 00:00:00 2001 From: Stefan Weinhuber Date: Fri, 29 Oct 2010 16:50:43 +0200 Subject: [PATCH] [S390] dasd: provide a Sense Path Group ID ioctl The BIODASDSNID ioctl executes a 'Sense Path Group ID' command on a DASD ECKD device. The returned path group data allows user space programs to determine path state and path group ID of the channel paths to the device. Signed-off-by: Stefan Weinhuber Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/dasd.h | 40 +++++++++++--------- drivers/s390/block/dasd_eckd.c | 69 ++++++++++++++++++++++++++++++++++ drivers/s390/block/dasd_eckd.h | 1 + 3 files changed, 92 insertions(+), 18 deletions(-) diff --git a/arch/s390/include/asm/dasd.h b/arch/s390/include/asm/dasd.h index 218bce81ec70..b604a9186f8e 100644 --- a/arch/s390/include/asm/dasd.h +++ b/arch/s390/include/asm/dasd.h @@ -217,6 +217,25 @@ typedef struct dasd_symmio_parms { int rssd_result_len; } __attribute__ ((packed)) dasd_symmio_parms_t; +/* + * Data returned by Sense Path Group ID (SNID) + */ +struct dasd_snid_data { + struct { + __u8 group:2; + __u8 reserve:2; + __u8 mode:1; + __u8 res:3; + } __attribute__ ((packed)) path_state; + __u8 pgid[11]; +} __attribute__ ((packed)); + +struct dasd_snid_ioctl_data { + struct dasd_snid_data data; + __u8 path_mask; +} __attribute__ ((packed)); + + /******************************************************************************** * SECTION: Definition of IOCTLs * @@ -261,25 +280,10 @@ typedef struct dasd_symmio_parms { /* Set Attributes (cache operations) */ #define BIODASDSATTR _IOW(DASD_IOCTL_LETTER,2,attrib_data_t) +/* Get Sense Path Group ID (SNID) data */ +#define BIODASDSNID _IOWR(DASD_IOCTL_LETTER, 1, struct dasd_snid_ioctl_data) + #define BIODASDSYMMIO _IOWR(DASD_IOCTL_LETTER, 240, dasd_symmio_parms_t) #endif /* DASD_H */ -/* - * Overrides for Emacs so that we follow Linus's tabbing style. - * Emacs will notice this stuff at the end of the file and automatically - * adjust the settings for this buffer only. This must remain at the end - * of the file. - * --------------------------------------------------------------------------- - * Local variables: - * c-indent-level: 4 - * c-brace-imaginary-offset: 0 - * c-brace-offset: -4 - * c-argdecl-indent: 4 - * c-label-offset: -4 - * c-continued-statement-offset: 4 - * c-continued-brace-offset: 0 - * indent-tabs-mode: nil - * tab-width: 8 - * End: - */ diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c index 50cf96389d2c..bf61274af3bb 100644 --- a/drivers/s390/block/dasd_eckd.c +++ b/drivers/s390/block/dasd_eckd.c @@ -2801,6 +2801,73 @@ dasd_eckd_steal_lock(struct dasd_device *device) return rc; } +/* + * SNID - Sense Path Group ID + * This ioctl may be used in situations where I/O is stalled due to + * a reserve, so if the normal dasd_smalloc_request fails, we use the + * preallocated dasd_reserve_req. + */ +static int dasd_eckd_snid(struct dasd_device *device, + void __user *argp) +{ + struct dasd_ccw_req *cqr; + int rc; + struct ccw1 *ccw; + int useglobal; + struct dasd_snid_ioctl_data usrparm; + + if (!capable(CAP_SYS_ADMIN)) + return -EACCES; + + if (copy_from_user(&usrparm, argp, sizeof(usrparm))) + return -EFAULT; + + useglobal = 0; + cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, 1, + sizeof(struct dasd_snid_data), device); + if (IS_ERR(cqr)) { + mutex_lock(&dasd_reserve_mutex); + useglobal = 1; + cqr = &dasd_reserve_req->cqr; + memset(cqr, 0, sizeof(*cqr)); + memset(&dasd_reserve_req->ccw, 0, + sizeof(dasd_reserve_req->ccw)); + cqr->cpaddr = &dasd_reserve_req->ccw; + cqr->data = &dasd_reserve_req->data; + cqr->magic = DASD_ECKD_MAGIC; + } + ccw = cqr->cpaddr; + ccw->cmd_code = DASD_ECKD_CCW_SNID; + ccw->flags |= CCW_FLAG_SLI; + ccw->count = 12; + ccw->cda = (__u32)(addr_t) cqr->data; + cqr->startdev = device; + cqr->memdev = device; + clear_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags); + set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags); + cqr->retries = 5; + cqr->expires = 10 * HZ; + cqr->buildclk = get_clock(); + cqr->status = DASD_CQR_FILLED; + cqr->lpm = usrparm.path_mask; + + rc = dasd_sleep_on_immediatly(cqr); + /* verify that I/O processing didn't modify the path mask */ + if (!rc && usrparm.path_mask && (cqr->lpm != usrparm.path_mask)) + rc = -EIO; + if (!rc) { + usrparm.data = *((struct dasd_snid_data *)cqr->data); + if (copy_to_user(argp, &usrparm, sizeof(usrparm))) + rc = -EFAULT; + } + + if (useglobal) + mutex_unlock(&dasd_reserve_mutex); + else + dasd_sfree_request(cqr, cqr->memdev); + return rc; +} + /* * Read performance statistics */ @@ -3036,6 +3103,8 @@ dasd_eckd_ioctl(struct dasd_block *block, unsigned int cmd, void __user *argp) return dasd_eckd_reserve(device); case BIODASDSLCK: return dasd_eckd_steal_lock(device); + case BIODASDSNID: + return dasd_eckd_snid(device, argp); case BIODASDSYMMIO: return dasd_symm_io(device, argp); default: diff --git a/drivers/s390/block/dasd_eckd.h b/drivers/s390/block/dasd_eckd.h index 0eb49655a6cd..12097c24f2f5 100644 --- a/drivers/s390/block/dasd_eckd.h +++ b/drivers/s390/block/dasd_eckd.h @@ -27,6 +27,7 @@ #define DASD_ECKD_CCW_WRITE_CKD 0x1d #define DASD_ECKD_CCW_READ_CKD 0x1e #define DASD_ECKD_CCW_PSF 0x27 +#define DASD_ECKD_CCW_SNID 0x34 #define DASD_ECKD_CCW_RSSD 0x3e #define DASD_ECKD_CCW_LOCATE_RECORD 0x47 #define DASD_ECKD_CCW_SNSS 0x54