From 196339f1733726ffd69ab81ec1c66678585f5846 Mon Sep 17 00:00:00 2001
From: Stefan Weinhuber <wein@de.ibm.com>
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 <wein@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---
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
--
2.34.1