[S390] Add ioctl support for EMC Symmetrix Subsystem Control I/O

EMC Symmetrix Subsystem Control I/O through CKD dasd requires a
specific parameter list sent to the array via a Perform Subsystem
Function CCW. The Symmetrix response is retrieved from the array
via a Read Subsystem Data CCW.

Signed-off-by: Nigel Hislop <hislop_nigel@emc.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 114 insertions, 0 deletions

diff --git a/arch/s390/include/asm/dasd.h b/arch/s390/include/asm/dasd.h
index 3f002e13d024..55b2b80cdf6e 100644
--- a/arch/s390/include/asm/dasd.h
+++ b/arch/s390/include/asm/dasd.h
@@ -3,6 +3,8 @@
  * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
  * Bugreports.to..: <Linux390@de.ibm.com>
  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
+ * EMC Symmetrix ioctl Copyright EMC Corporation, 2008
+ * Author.........: Nigel Hislop <hislop_nigel@emc.com>
  *
  * This file is the interface of the DASD device driver, which is exported to user space
  * any future changes wrt the API will result in a change of the APIVERSION reported
@@ -202,6 +204,16 @@ typedef struct attrib_data_t {
 #define DASD_SEQ_PRESTAGE  0x4
 #define DASD_REC_ACCESS    0x5
 
+/*
+ * Perform EMC Symmetrix I/O
+ */
+typedef struct dasd_symmio_parms {
+        unsigned char reserved[8];      /* compat with older releases */
+        unsigned long long psf_data;    /* char * cast to u64 */
+        unsigned long long rssd_result; /* char * cast to u64 */
+        int psf_data_len;
+        int rssd_result_len;
+} __attribute__ ((packed)) dasd_symmio_parms_t;
 
 /********************************************************************************
  * SECTION: Definition of IOCTLs
@@ -247,6 +259,7 @@ typedef struct attrib_data_t {
 /* Set Attributes (cache operations) */
 #define BIODASDSATTR   _IOW(DASD_IOCTL_LETTER,2,attrib_data_t) 
 
+#define BIODASDSYMMIO  _IOWR(DASD_IOCTL_LETTER, 240, dasd_symmio_parms_t)
 
 #endif                          /* DASD_H */
 
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 8095629bc493..49f9d221e23d 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -6,6 +6,8 @@
  *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
  * Bugreports.to..: <Linux390@de.ibm.com>
  * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 1999,2000
+ * EMC Symmetrix ioctl Copyright EMC Corporation, 2008
+ * Author.........: Nigel Hislop <hislop_nigel@emc.com>
  *
  */
 
@@ -2083,6 +2085,103 @@ dasd_eckd_set_attrib(struct dasd_device *device, void __user *argp)
         return 0;
 }
 
+/*
+ * Issue syscall I/O to EMC Symmetrix array.
+ * CCWs are PSF and RSSD
+ */
+static int dasd_symm_io(struct dasd_device *device, void __user *argp)
+{
+        struct dasd_symmio_parms usrparm;
+        char *psf_data, *rssd_result;
+        struct dasd_ccw_req *cqr;
+        struct ccw1 *ccw;
+        int rc;
+
+        /* Copy parms from caller */
+        rc = -EFAULT;
+        if (copy_from_user(&usrparm, argp, sizeof(usrparm)))
+                goto out;
+#ifndef CONFIG_64BIT
+        /* Make sure pointers are sane even on 31 bit. */
+        if ((usrparm.psf_data >> 32) != 0 || (usrparm.rssd_result >> 32) != 0) {
+                rc = -EINVAL;
+                goto out;
+        }
+#endif
+        /* alloc I/O data area */
+        psf_data = kzalloc(usrparm.psf_data_len, GFP_KERNEL | GFP_DMA);
+        rssd_result = kzalloc(usrparm.rssd_result_len, GFP_KERNEL | GFP_DMA);
+        if (!psf_data || !rssd_result) {
+                rc = -ENOMEM;
+                goto out_free;
+        }
+
+        /* get syscall header from user space */
+        rc = -EFAULT;
+        if (copy_from_user(psf_data,
+                           (void __user *)(unsigned long) usrparm.psf_data,
+                           usrparm.psf_data_len))
+                goto out_free;
+
+        /* sanity check on syscall header */
+        if (psf_data[0] != 0x17 && psf_data[1] != 0xce) {
+                rc = -EINVAL;
+                goto out_free;
+        }
+
+        /* setup CCWs for PSF + RSSD */
+        cqr = dasd_smalloc_request("ECKD", 2 , 0, device);
+        if (IS_ERR(cqr)) {
+                DEV_MESSAGE(KERN_WARNING, device, "%s",
+                        "Could not allocate initialization request");
+                rc = PTR_ERR(cqr);
+                goto out_free;
+        }
+
+        cqr->startdev = device;
+        cqr->memdev = device;
+        cqr->retries = 3;
+        cqr->expires = 10 * HZ;
+        cqr->buildclk = get_clock();
+        cqr->status = DASD_CQR_FILLED;
+
+        /* Build the ccws */
+        ccw = cqr->cpaddr;
+
+        /* PSF ccw */
+        ccw->cmd_code = DASD_ECKD_CCW_PSF;
+        ccw->count = usrparm.psf_data_len;
+        ccw->flags |= CCW_FLAG_CC;
+        ccw->cda = (__u32)(addr_t) psf_data;
+
+        ccw++;
+
+        /* RSSD ccw  */
+        ccw->cmd_code = DASD_ECKD_CCW_RSSD;
+        ccw->count = usrparm.rssd_result_len;
+        ccw->flags = CCW_FLAG_SLI ;
+        ccw->cda = (__u32)(addr_t) rssd_result;
+
+        rc = dasd_sleep_on(cqr);
+        if (rc)
+                goto out_sfree;
+
+        rc = -EFAULT;
+        if (copy_to_user((void __user *)(unsigned long) usrparm.rssd_result,
+                           rssd_result, usrparm.rssd_result_len))
+                goto out_sfree;
+        rc = 0;
+
+out_sfree:
+        dasd_sfree_request(cqr, cqr->memdev);
+out_free:
+        kfree(rssd_result);
+        kfree(psf_data);
+out:
+        DBF_DEV_EVENT(DBF_WARNING, device, "Symmetrix ioctl: rc=%d", rc);
+        return rc;
+}
+
 static int
 dasd_eckd_ioctl(struct dasd_block *block, unsigned int cmd, void __user *argp)
 {
@@ -2101,6 +2200,8 @@ 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 BIODASDSYMMIO:
+                return dasd_symm_io(device, argp);
         default:
                 return -ENOIOCTLCMD;
         }