s390/dasd: add support for control unit initiated reconfiguration

Add support for Control Unit Initiated Reconfiguration (CUIR) to
Linux, a storage server interface to reconcile concurrent hardware
changes between storage and host.
Reviewed-by: Stefan Weinhuber <wein@de.ibm.com>
Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/block/dasd.c

@@ -1660,6 +1660,14 @@ void dasd_int_handler(struct ccw_device *cdev, unsigned long intparm,
 		device->discipline->check_for_device_change(device, cqr, irb);
 		dasd_put_device(device);
 	}
+
+	/* check for for attention message */
+	if (scsw_dstat(&irb->scsw) & DEV_STAT_ATTENTION) {
+		device = dasd_device_from_cdev_locked(cdev);
+		device->discipline->check_attention(device, irb->esw.esw1.lpum);
+		dasd_put_device(device);
+	}
+
 	if (!cqr)
 		return;
 

drivers/s390/block/dasd_devmap.c

@@ -1432,6 +1432,29 @@ static ssize_t dasd_reservation_state_store(struct device *dev,
 static DEVICE_ATTR(last_known_reservation_state, 0644,
 		   dasd_reservation_state_show, dasd_reservation_state_store);
 
+static ssize_t dasd_pm_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct dasd_device *device;
+	u8 opm, nppm, cablepm, cuirpm, hpfpm;
+
+	device = dasd_device_from_cdev(to_ccwdev(dev));
+	if (IS_ERR(device))
+		return sprintf(buf, "0\n");
+
+	opm = device->path_data.opm;
+	nppm = device->path_data.npm;
+	cablepm = device->path_data.cablepm;
+	cuirpm = device->path_data.cuirpm;
+	hpfpm = device->path_data.hpfpm;
+	dasd_put_device(device);
+
+	return sprintf(buf, "%02x %02x %02x %02x %02x\n", opm, nppm,
+		       cablepm, cuirpm, hpfpm);
+}
+
+static DEVICE_ATTR(path_masks, 0444, dasd_pm_show, NULL);
+
 static struct attribute * dasd_attrs[] = {
 	&dev_attr_readonly.attr,
 	&dev_attr_discipline.attr,
@@ -1450,6 +1473,7 @@ static struct attribute * dasd_attrs[] = {
 	&dev_attr_reservation_policy.attr,
 	&dev_attr_last_known_reservation_state.attr,
 	&dev_attr_safe_offline.attr,
+	&dev_attr_path_masks.attr,
 	NULL,
 };
 

drivers/s390/block/dasd_eckd.h

@@ -51,8 +51,35 @@
 /*
  * Perform Subsystem Function / Sub-Orders
  */
-#define PSF_ORDER_PRSSD 0x18
-#define PSF_ORDER_SSC	0x1D
+#define PSF_ORDER_PRSSD			 0x18
+#define PSF_ORDER_CUIR_RESPONSE		 0x1A
+#define PSF_ORDER_SSC			 0x1D
+
+/*
+ * CUIR response condition codes
+ */
+#define PSF_CUIR_INVALID		 0x00
+#define PSF_CUIR_COMPLETED		 0x01
+#define PSF_CUIR_NOT_SUPPORTED		 0x02
+#define PSF_CUIR_ERROR_IN_REQ		 0x03
+#define PSF_CUIR_DENIED			 0x04
+#define PSF_CUIR_LAST_PATH		 0x05
+#define PSF_CUIR_DEVICE_ONLINE		 0x06
+#define PSF_CUIR_VARY_FAILURE		 0x07
+#define PSF_CUIR_SOFTWARE_FAILURE	 0x08
+#define PSF_CUIR_NOT_RECOGNIZED		 0x09
+
+/*
+ * CUIR codes
+ */
+#define CUIR_QUIESCE			 0x01
+#define CUIR_RESUME			 0x02
+
+/*
+ * attention message definitions
+ */
+#define ATTENTION_LENGTH_CUIR		 0x0e
+#define ATTENTION_FORMAT_CUIR		 0x01
 
 /*
  * Size that is reportet for large volumes in the old 16-bit no_cyl field
@@ -342,6 +369,38 @@ struct dasd_rssd_features {
 	char feature[256];
 } __attribute__((packed));
 
+struct dasd_rssd_messages {
+	__u16 length;
+	__u8 format;
+	__u8 code;
+	__u32 message_id;
+	__u8 flags;
+	char messages[4087];
+} __packed;
+
+struct dasd_cuir_message {
+	__u16 length;
+	__u8 format;
+	__u8 code;
+	__u32 message_id;
+	__u8 flags;
+	__u8 neq_map[3];
+	__u8 ned_map;
+	__u8 record_selector;
+} __packed;
+
+struct dasd_psf_cuir_response {
+	__u8 order;
+	__u8 flags;
+	__u8 cc;
+	__u8 chpid;
+	__u16 device_nr;
+	__u16 reserved;
+	__u32 message_id;
+	__u64 system_id;
+	__u8 cssid;
+	__u8 ssid;
+} __packed;
 
 /*
  * Perform Subsystem Function - Prepare for Read Subsystem Data

drivers/s390/block/dasd_int.h

@@ -357,6 +357,7 @@ struct dasd_discipline {
 
 	int (*get_uid) (struct dasd_device *, struct dasd_uid *);
 	void (*kick_validate) (struct dasd_device *);
+	int (*check_attention)(struct dasd_device *, __u8);
 };
 
 extern struct dasd_discipline *dasd_diag_discipline_pointer;
@@ -382,6 +383,10 @@ struct dasd_path {
 	__u8 tbvpm;
 	__u8 ppm;
 	__u8 npm;
+	/* paths that are not used because of a special condition */
+	__u8 cablepm; /* miss-cabled */
+	__u8 hpfpm;   /* the HPF requirements of the other paths are not met */
+	__u8 cuirpm;  /* CUIR varied offline */
 };
 
 struct dasd_profile_info {
@@ -501,7 +506,10 @@ struct dasd_block {
 	struct dasd_profile profile;
 };
 
-
+struct dasd_attention_data {
+	struct dasd_device *device;
+	__u8 lpum;
+};
 
 /* reasons why device (ccw_device_start) was stopped */
 #define DASD_STOPPED_NOT_ACC 1         /* not accessible */