s390/dasd: Refactor prefix_LRE() and related functions

We already have define_extent() that prepares necessary data for the
Define Extent CCW. The exact same thing is done in prefix_LRE().

Remove the duplicate code and move commands that were only used in
combination with the Prefix command to define_extent(). One of these
commands needs the blocksize to be specified. Add the blksize parameter
to define_extent() to account for that.

In addition, the check_XRC() function can be made more generic. Do this
and remove the Prefix-specific check_XRC_on_prefix() function.

Furthermore, prefix_LRE() uses fill_LRE_data() to prepare Locate Record
Extended data. Rename the function to fit the scheme better and make it
usable outside of the Prefix context by adding the corresponding CCW
command.

Reviewed-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 78 insertions, 140 deletions

diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 122456e4db89..4fdf1101bd2f 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -213,10 +213,8 @@ static void set_ch_t(struct ch_t *geo, __u32 cyl, __u8 head)
 	geo->head |= head;
 }
 
-static int
-check_XRC (struct ccw1         *de_ccw,
-           struct DE_eckd_data *data,
-           struct dasd_device  *device)
+static int check_XRC(struct ccw1 *ccw, struct DE_eckd_data *data,
+		     struct dasd_device *device)
 {
 	struct dasd_eckd_private *private = device->private;
 	int rc;
@@ -224,7 +222,7 @@ check_XRC (struct ccw1         *de_ccw,
 	if (!private->rdc_data.facilities.XRC_supported)
 		return 0;
 
-        /* switch on System Time Stamp - needed for XRC Support */
+	/* switch on System Time Stamp - needed for XRC Support */
 	data->ga_extended |= 0x08; /* switch on 'Time Stamp Valid'   */
 	data->ga_extended |= 0x02; /* switch on 'Extended Parameter' */
 
@@ -233,24 +231,30 @@ check_XRC (struct ccw1         *de_ccw,
 	if (rc == -EOPNOTSUPP || rc == -EACCES)
 		rc = 0;
 
-	de_ccw->count = sizeof(struct DE_eckd_data);
-	de_ccw->flags |= CCW_FLAG_SLI;
+	if (ccw) {
+		ccw->count = sizeof(struct DE_eckd_data);
+		ccw->flags |= CCW_FLAG_SLI;
+	}
+
 	return rc;
 }
 
 static int
 define_extent(struct ccw1 *ccw, struct DE_eckd_data *data, unsigned int trk,
-	      unsigned int totrk, int cmd, struct dasd_device *device)
+	      unsigned int totrk, int cmd, struct dasd_device *device,
+	      int blksize)
 {
 	struct dasd_eckd_private *private = device->private;
-	u32 begcyl, endcyl;
 	u16 heads, beghead, endhead;
+	u32 begcyl, endcyl;
 	int rc = 0;
 
-	ccw->cmd_code = DASD_ECKD_CCW_DEFINE_EXTENT;
-	ccw->flags = 0;
-	ccw->count = 16;
-	ccw->cda = (__u32) __pa(data);
+	if (ccw) {
+		ccw->cmd_code = DASD_ECKD_CCW_DEFINE_EXTENT;
+		ccw->flags = 0;
+		ccw->count = 16;
+		ccw->cda = (__u32)__pa(data);
+	}
 
 	memset(data, 0, sizeof(struct DE_eckd_data));
 	switch (cmd) {
@@ -269,18 +273,24 @@ define_extent(struct ccw1 *ccw, struct DE_eckd_data *data, unsigned int trk,
 		data->mask.perm = 0x1;
 		data->attributes.operation = DASD_BYPASS_CACHE;
 		break;
+	case DASD_ECKD_CCW_READ_TRACK:
+	case DASD_ECKD_CCW_READ_TRACK_DATA:
+		data->mask.perm = 0x1;
+		data->attributes.operation = private->attrib.operation;
+		data->blk_size = 0;
+		break;
 	case DASD_ECKD_CCW_WRITE:
 	case DASD_ECKD_CCW_WRITE_MT:
 	case DASD_ECKD_CCW_WRITE_KD:
 	case DASD_ECKD_CCW_WRITE_KD_MT:
 		data->mask.perm = 0x02;
 		data->attributes.operation = private->attrib.operation;
-		rc = check_XRC (ccw, data, device);
+		rc = check_XRC(ccw, data, device);
 		break;
 	case DASD_ECKD_CCW_WRITE_CKD:
 	case DASD_ECKD_CCW_WRITE_CKD_MT:
 		data->attributes.operation = DASD_BYPASS_CACHE;
-		rc = check_XRC (ccw, data, device);
+		rc = check_XRC(ccw, data, device);
 		break;
 	case DASD_ECKD_CCW_ERASE:
 	case DASD_ECKD_CCW_WRITE_HOME_ADDRESS:
@@ -288,7 +298,18 @@ define_extent(struct ccw1 *ccw, struct DE_eckd_data *data, unsigned int trk,
 		data->mask.perm = 0x3;
 		data->mask.auth = 0x1;
 		data->attributes.operation = DASD_BYPASS_CACHE;
-		rc = check_XRC (ccw, data, device);
+		rc = check_XRC(ccw, data, device);
+		break;
+	case DASD_ECKD_CCW_WRITE_FULL_TRACK:
+		data->mask.perm = 0x03;
+		data->attributes.operation = private->attrib.operation;
+		data->blk_size = 0;
+		break;
+	case DASD_ECKD_CCW_WRITE_TRACK_DATA:
+		data->mask.perm = 0x02;
+		data->attributes.operation = private->attrib.operation;
+		data->blk_size = blksize;
+		rc = check_XRC(ccw, data, device);
 		break;
 	default:
 		dev_err(&device->cdev->dev,
@@ -325,36 +346,26 @@ define_extent(struct ccw1 *ccw, struct DE_eckd_data *data, unsigned int trk,
 	return rc;
 }
 
-static int check_XRC_on_prefix(struct PFX_eckd_data *pfxdata,
-			       struct dasd_device  *device)
-{
-	struct dasd_eckd_private *private = device->private;
-	int rc;
 
-	if (!private->rdc_data.facilities.XRC_supported)
-		return 0;
-
-	/* switch on System Time Stamp - needed for XRC Support */
-	pfxdata->define_extent.ga_extended |= 0x08; /* 'Time Stamp Valid'   */
-	pfxdata->define_extent.ga_extended |= 0x02; /* 'Extended Parameter' */
-	pfxdata->validity.time_stamp = 1;	    /* 'Time Stamp Valid'   */
-
-	rc = get_phys_clock(&pfxdata->define_extent.ep_sys_time);
-	/* Ignore return code if sync clock is switched off. */
-	if (rc == -EOPNOTSUPP || rc == -EACCES)
-		rc = 0;
-	return rc;
-}
-
-static void fill_LRE_data(struct LRE_eckd_data *data, unsigned int trk,
-			  unsigned int rec_on_trk, int count, int cmd,
-			  struct dasd_device *device, unsigned int reclen,
-			  unsigned int tlf)
+static void locate_record_ext(struct ccw1 *ccw, struct LRE_eckd_data *data,
+			      unsigned int trk, unsigned int rec_on_trk,
+			      int count, int cmd, struct dasd_device *device,
+			      unsigned int reclen, unsigned int tlf)
 {
 	struct dasd_eckd_private *private = device->private;
 	int sector;
 	int dn, d;
 
+	if (ccw) {
+		ccw->cmd_code = DASD_ECKD_CCW_LOCATE_RECORD_EXT;
+		ccw->flags = 0;
+		if (cmd == DASD_ECKD_CCW_WRITE_FULL_TRACK)
+			ccw->count = 22;
+		else
+			ccw->count = 20;
+		ccw->cda = (__u32)__pa(data);
+	}
+
 	memset(data, 0, sizeof(*data));
 	sector = 0;
 	if (rec_on_trk) {
@@ -481,14 +492,12 @@ static void fill_LRE_data(struct LRE_eckd_data *data, unsigned int trk,
 static int prefix_LRE(struct ccw1 *ccw, struct PFX_eckd_data *pfxdata,
 		      unsigned int trk, unsigned int totrk, int cmd,
 		      struct dasd_device *basedev, struct dasd_device *startdev,
-		      unsigned char format, unsigned int rec_on_trk, int count,
+		      unsigned int format, unsigned int rec_on_trk, int count,
 		      unsigned int blksize, unsigned int tlf)
 {
 	struct dasd_eckd_private *basepriv, *startpriv;
-	struct DE_eckd_data *dedata;
 	struct LRE_eckd_data *lredata;
-	u32 begcyl, endcyl;
-	u16 heads, beghead, endhead;
+	struct DE_eckd_data *dedata;
 	int rc = 0;
 
 	basepriv = basedev->private;
@@ -527,98 +536,19 @@ static int prefix_LRE(struct ccw1 *ccw, struct PFX_eckd_data *pfxdata,
 			pfxdata->validity.hyper_pav = 1;
 	}
 
-	/* define extend data (mostly)*/
-	switch (cmd) {
-	case DASD_ECKD_CCW_READ_HOME_ADDRESS:
-	case DASD_ECKD_CCW_READ_RECORD_ZERO:
-	case DASD_ECKD_CCW_READ:
-	case DASD_ECKD_CCW_READ_MT:
-	case DASD_ECKD_CCW_READ_CKD:
-	case DASD_ECKD_CCW_READ_CKD_MT:
-	case DASD_ECKD_CCW_READ_KD:
-	case DASD_ECKD_CCW_READ_KD_MT:
-		dedata->mask.perm = 0x1;
-		dedata->attributes.operation = basepriv->attrib.operation;
-		break;
-	case DASD_ECKD_CCW_READ_COUNT:
-		dedata->mask.perm = 0x1;
-		dedata->attributes.operation = DASD_BYPASS_CACHE;
-		break;
-	case DASD_ECKD_CCW_READ_TRACK:
-	case DASD_ECKD_CCW_READ_TRACK_DATA:
-		dedata->mask.perm = 0x1;
-		dedata->attributes.operation = basepriv->attrib.operation;
-		dedata->blk_size = 0;
-		break;
-	case DASD_ECKD_CCW_WRITE:
-	case DASD_ECKD_CCW_WRITE_MT:
-	case DASD_ECKD_CCW_WRITE_KD:
-	case DASD_ECKD_CCW_WRITE_KD_MT:
-		dedata->mask.perm = 0x02;
-		dedata->attributes.operation = basepriv->attrib.operation;
-		rc = check_XRC_on_prefix(pfxdata, basedev);
-		break;
-	case DASD_ECKD_CCW_WRITE_CKD:
-	case DASD_ECKD_CCW_WRITE_CKD_MT:
-		dedata->attributes.operation = DASD_BYPASS_CACHE;
-		rc = check_XRC_on_prefix(pfxdata, basedev);
-		break;
-	case DASD_ECKD_CCW_ERASE:
-	case DASD_ECKD_CCW_WRITE_HOME_ADDRESS:
-	case DASD_ECKD_CCW_WRITE_RECORD_ZERO:
-		dedata->mask.perm = 0x3;
-		dedata->mask.auth = 0x1;
-		dedata->attributes.operation = DASD_BYPASS_CACHE;
-		rc = check_XRC_on_prefix(pfxdata, basedev);
-		break;
-	case DASD_ECKD_CCW_WRITE_FULL_TRACK:
-		dedata->mask.perm = 0x03;
-		dedata->attributes.operation = basepriv->attrib.operation;
-		dedata->blk_size = 0;
-		break;
-	case DASD_ECKD_CCW_WRITE_TRACK_DATA:
-		dedata->mask.perm = 0x02;
-		dedata->attributes.operation = basepriv->attrib.operation;
-		dedata->blk_size = blksize;
-		rc = check_XRC_on_prefix(pfxdata, basedev);
-		break;
-	default:
-		DBF_DEV_EVENT(DBF_ERR, basedev,
-			    "PFX LRE unknown opcode 0x%x", cmd);
-		BUG();
-		return -EINVAL;
-	}
-
-	dedata->attributes.mode = 0x3;	/* ECKD */
-
-	if ((basepriv->rdc_data.cu_type == 0x2105 ||
-	     basepriv->rdc_data.cu_type == 0x2107 ||
-	     basepriv->rdc_data.cu_type == 0x1750)
-	    && !(basepriv->uses_cdl && trk < 2))
-		dedata->ga_extended |= 0x40; /* Regular Data Format Mode */
-
-	heads = basepriv->rdc_data.trk_per_cyl;
-	begcyl = trk / heads;
-	beghead = trk % heads;
-	endcyl = totrk / heads;
-	endhead = totrk % heads;
-
-	/* check for sequential prestage - enhance cylinder range */
-	if (dedata->attributes.operation == DASD_SEQ_PRESTAGE ||
-	    dedata->attributes.operation == DASD_SEQ_ACCESS) {
-
-		if (endcyl + basepriv->attrib.nr_cyl < basepriv->real_cyl)
-			endcyl += basepriv->attrib.nr_cyl;
-		else
-			endcyl = (basepriv->real_cyl - 1);
-	}
+	rc = define_extent(NULL, dedata, trk, totrk, cmd, basedev, blksize);
 
-	set_ch_t(&dedata->beg_ext, begcyl, beghead);
-	set_ch_t(&dedata->end_ext, endcyl, endhead);
+	/*
+	 * For some commands the System Time Stamp is set in the define extent
+	 * data when XRC is supported. The validity of the time stamp must be
+	 * reflected in the prefix data as well.
+	 */
+	if (dedata->ga_extended & 0x08 && dedata->ga_extended & 0x02)
+		pfxdata->validity.time_stamp = 1; /* 'Time Stamp Valid'   */
 
 	if (format == 1) {
-		fill_LRE_data(lredata, trk, rec_on_trk, count, cmd,
-			      basedev, blksize, tlf);
+		locate_record_ext(NULL, lredata, trk, rec_on_trk, count, cmd,
+				  basedev, blksize, tlf);
 	}
 
 	return rc;
@@ -1887,7 +1817,7 @@ dasd_eckd_analysis_ccw(struct dasd_device *device)
 	ccw = cqr->cpaddr;
 	/* Define extent for the first 3 tracks. */
 	define_extent(ccw++, cqr->data, 0, 2,
-		      DASD_ECKD_CCW_READ_COUNT, device);
+		      DASD_ECKD_CCW_READ_COUNT, device, 0);
 	LO_data = cqr->data + sizeof(struct DE_eckd_data);
 	/* Locate record for the first 4 records on track 0. */
 	ccw[-1].flags |= CCW_FLAG_CC;
@@ -2266,7 +2196,7 @@ dasd_eckd_build_check(struct dasd_device *base, struct format_data_t *fdata,
 			   count, 0, 0);
 	} else {
 		define_extent(ccw++, data, fdata->start_unit, fdata->stop_unit,
-			      DASD_ECKD_CCW_READ_COUNT, startdev);
+			      DASD_ECKD_CCW_READ_COUNT, startdev, 0);
 
 		data += sizeof(struct DE_eckd_data);
 		ccw[-1].flags |= CCW_FLAG_CC;
@@ -2420,7 +2350,7 @@ dasd_eckd_build_format(struct dasd_device *base,
 		} else {
 			define_extent(ccw++, (struct DE_eckd_data *) data,
 				      fdata->start_unit, fdata->stop_unit,
-				      DASD_ECKD_CCW_WRITE_CKD, startdev);
+				      DASD_ECKD_CCW_WRITE_CKD, startdev, 0);
 			/* grant subsystem permission to format R0 */
 			if (r0_perm)
 				((struct DE_eckd_data *) data)
@@ -2444,7 +2374,7 @@ dasd_eckd_build_format(struct dasd_device *base,
 		} else {
 			define_extent(ccw++, (struct DE_eckd_data *) data,
 			       fdata->start_unit, fdata->stop_unit,
-			       DASD_ECKD_CCW_WRITE_RECORD_ZERO, startdev);
+			       DASD_ECKD_CCW_WRITE_RECORD_ZERO, startdev, 0);
 			data += sizeof(struct DE_eckd_data);
 		}
 		ccw[-1].flags |= CCW_FLAG_CC;
@@ -2463,7 +2393,7 @@ dasd_eckd_build_format(struct dasd_device *base,
 		} else {
 			define_extent(ccw++, (struct DE_eckd_data *) data,
 			       fdata->start_unit, fdata->stop_unit,
-			       DASD_ECKD_CCW_WRITE_CKD, startdev);
+			       DASD_ECKD_CCW_WRITE_CKD, startdev, 0);
 			data += sizeof(struct DE_eckd_data);
 		}
 		ccw[-1].flags |= CCW_FLAG_CC;
@@ -3187,7 +3117,7 @@ static struct dasd_ccw_req *dasd_eckd_build_cp_cmd_single(
 					   sizeof(struct PFX_eckd_data));
 	} else {
 		if (define_extent(ccw++, cqr->data, first_trk,
-				  last_trk, cmd, basedev) == -EAGAIN) {
+				  last_trk, cmd, basedev, 0) == -EAGAIN) {
 			/* Clock not in sync and XRC is enabled.
 			 * Try again later.
 			 */
@@ -3509,12 +3439,19 @@ static int prepare_itcw(struct itcw *itcw,
 		dedata->mask.perm = 0x02;
 		dedata->attributes.operation = basepriv->attrib.operation;
 		dedata->blk_size = blksize;
-		rc = check_XRC_on_prefix(&pfxdata, basedev);
+		rc = check_XRC(NULL, dedata, basedev);
 		dedata->ga_extended |= 0x42;
 		lredata->operation.orientation = 0x0;
 		lredata->operation.operation = 0x3F;
 		lredata->extended_operation = 0x23;
 		lredata->auxiliary.check_bytes = 0x2;
+		/*
+		 * If XRC is supported the System Time Stamp is set. The
+		 * validity of the time stamp must be reflected in the prefix
+		 * data as well.
+		 */
+		if (dedata->ga_extended & 0x08 && dedata->ga_extended & 0x02)
+			pfxdata.validity.time_stamp = 1; /* 'Time Stamp Valid' */
 		pfx_cmd = DASD_ECKD_CCW_PFX;
 		break;
 	case DASD_ECKD_CCW_READ_COUNT_MT:
diff --git a/drivers/s390/block/dasd_eckd.h b/drivers/s390/block/dasd_eckd.h
index e2a710c250a5..fb1f537d986a 100644
--- a/drivers/s390/block/dasd_eckd.h
+++ b/drivers/s390/block/dasd_eckd.h
@@ -29,6 +29,7 @@
 #define DASD_ECKD_CCW_SNID		 0x34
 #define DASD_ECKD_CCW_RSSD		 0x3e
 #define DASD_ECKD_CCW_LOCATE_RECORD	 0x47
+#define DASD_ECKD_CCW_LOCATE_RECORD_EXT	 0x4b
 #define DASD_ECKD_CCW_SNSS		 0x54
 #define DASD_ECKD_CCW_DEFINE_EXTENT	 0x63
 #define DASD_ECKD_CCW_WRITE_MT		 0x85