[S390] dasd: Add support for raw ECKD access.
authorStefan Haberland <stefan.haberland@de.ibm.com>
Wed, 5 Jan 2011 11:48:06 +0000 (12:48 +0100)
committerMartin Schwidefsky <sky@mschwide.boeblingen.de.ibm.com>
Wed, 5 Jan 2011 11:47:30 +0000 (12:47 +0100)
Normal I/O operations through the DASD device driver give only access
to the data fields of an ECKD device even for track based I/O.
This patch extends the DASD device driver to give access to whole
ECKD tracks including count, key and data fields.

Signed-off-by: Stefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
arch/s390/include/asm/dasd.h
drivers/s390/block/dasd.c
drivers/s390/block/dasd_devmap.c
drivers/s390/block/dasd_eckd.c
drivers/s390/block/dasd_eckd.h

index 47fcdad..0be28ef 100644 (file)
@@ -73,6 +73,7 @@ typedef struct dasd_information2_t {
  * 0x02: use diag discipline (diag)
  * 0x04: set the device initially online (internal use only)
  * 0x08: enable ERP related logging
+ * 0x20: give access to raw eckd data
  */
 #define DASD_FEATURE_DEFAULT        0x00
 #define DASD_FEATURE_READONLY       0x01
@@ -81,6 +82,7 @@ typedef struct dasd_information2_t {
 #define DASD_FEATURE_ERPLOG         0x08
 #define DASD_FEATURE_FAILFAST       0x10
 #define DASD_FEATURE_FAILONSLCK      0x20
+#define DASD_FEATURE_USERAW         0x40
 
 #define DASD_PARTN_BITS 2
 
index 82d9ce3..4e266f4 100644 (file)
@@ -369,6 +369,11 @@ dasd_state_ready_to_online(struct dasd_device * device)
        device->state = DASD_STATE_ONLINE;
        if (device->block) {
                dasd_schedule_block_bh(device->block);
+               if ((device->features & DASD_FEATURE_USERAW)) {
+                       disk = device->block->gdp;
+                       kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
+                       return 0;
+               }
                disk = device->block->bdev->bd_disk;
                disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
                while ((part = disk_part_iter_next(&piter)))
@@ -394,7 +399,7 @@ static int dasd_state_online_to_ready(struct dasd_device *device)
                        return rc;
        }
        device->state = DASD_STATE_READY;
-       if (device->block) {
+       if (device->block && !(device->features & DASD_FEATURE_USERAW)) {
                disk = device->block->bdev->bd_disk;
                disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
                while ((part = disk_part_iter_next(&piter)))
@@ -2258,8 +2263,20 @@ static void dasd_setup_queue(struct dasd_block *block)
 {
        int max;
 
-       blk_queue_logical_block_size(block->request_queue, block->bp_block);
-       max = block->base->discipline->max_blocks << block->s2b_shift;
+       if (block->base->features & DASD_FEATURE_USERAW) {
+               /*
+                * the max_blocks value for raw_track access is 256
+                * it is higher than the native ECKD value because we
+                * only need one ccw per track
+                * so the max_hw_sectors are
+                * 2048 x 512B = 1024kB = 16 tracks
+                */
+               max = 2048;
+       } else {
+               max = block->base->discipline->max_blocks << block->s2b_shift;
+       }
+       blk_queue_logical_block_size(block->request_queue,
+                                    block->bp_block);
        blk_queue_max_hw_sectors(block->request_queue, max);
        blk_queue_max_segments(block->request_queue, -1L);
        /* with page sized segments we can translate each segement into
index 47fc886..cb6a67b 100644 (file)
@@ -208,6 +208,8 @@ dasd_feature_list(char *str, char **endp)
                        features |= DASD_FEATURE_READONLY;
                else if (len == 4 && !strncmp(str, "diag", 4))
                        features |= DASD_FEATURE_USEDIAG;
+               else if (len == 3 && !strncmp(str, "raw", 3))
+                       features |= DASD_FEATURE_USERAW;
                else if (len == 6 && !strncmp(str, "erplog", 6))
                        features |= DASD_FEATURE_ERPLOG;
                else if (len == 8 && !strncmp(str, "failfast", 8))
@@ -857,7 +859,7 @@ dasd_use_diag_store(struct device *dev, struct device_attribute *attr,
        spin_lock(&dasd_devmap_lock);
        /* Changing diag discipline flag is only allowed in offline state. */
        rc = count;
-       if (!devmap->device) {
+       if (!devmap->device && !(devmap->features & DASD_FEATURE_USERAW)) {
                if (val)
                        devmap->features |= DASD_FEATURE_USEDIAG;
                else
@@ -870,6 +872,56 @@ dasd_use_diag_store(struct device *dev, struct device_attribute *attr,
 
 static DEVICE_ATTR(use_diag, 0644, dasd_use_diag_show, dasd_use_diag_store);
 
+/*
+ * use_raw controls whether the driver should give access to raw eckd data or
+ * operate in standard mode
+ */
+static ssize_t
+dasd_use_raw_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+       struct dasd_devmap *devmap;
+       int use_raw;
+
+       devmap = dasd_find_busid(dev_name(dev));
+       if (!IS_ERR(devmap))
+               use_raw = (devmap->features & DASD_FEATURE_USERAW) != 0;
+       else
+               use_raw = (DASD_FEATURE_DEFAULT & DASD_FEATURE_USERAW) != 0;
+       return sprintf(buf, use_raw ? "1\n" : "0\n");
+}
+
+static ssize_t
+dasd_use_raw_store(struct device *dev, struct device_attribute *attr,
+                   const char *buf, size_t count)
+{
+       struct dasd_devmap *devmap;
+       ssize_t rc;
+       unsigned long val;
+
+       devmap = dasd_devmap_from_cdev(to_ccwdev(dev));
+       if (IS_ERR(devmap))
+               return PTR_ERR(devmap);
+
+       if ((strict_strtoul(buf, 10, &val) != 0) || val > 1)
+               return -EINVAL;
+
+       spin_lock(&dasd_devmap_lock);
+       /* Changing diag discipline flag is only allowed in offline state. */
+       rc = count;
+       if (!devmap->device && !(devmap->features & DASD_FEATURE_USEDIAG)) {
+               if (val)
+                       devmap->features |= DASD_FEATURE_USERAW;
+               else
+                       devmap->features &= ~DASD_FEATURE_USERAW;
+       } else
+               rc = -EPERM;
+       spin_unlock(&dasd_devmap_lock);
+       return rc;
+}
+
+static DEVICE_ATTR(raw_track_access, 0644, dasd_use_raw_show,
+                  dasd_use_raw_store);
+
 static ssize_t
 dasd_discipline_show(struct device *dev, struct device_attribute *attr,
                     char *buf)
@@ -1232,6 +1284,7 @@ static struct attribute * dasd_attrs[] = {
        &dev_attr_vendor.attr,
        &dev_attr_uid.attr,
        &dev_attr_use_diag.attr,
+       &dev_attr_raw_track_access.attr,
        &dev_attr_eer_enabled.attr,
        &dev_attr_erplog.attr,
        &dev_attr_failfast.attr,
index 46eafce..318672d 100644 (file)
 #define ECKD_F7(i) (i->factor7)
 #define ECKD_F8(i) (i->factor8)
 
+/*
+ * raw track access always map to 64k in memory
+ * so it maps to 16 blocks of 4k per track
+ */
+#define DASD_RAW_BLOCK_PER_TRACK 16
+#define DASD_RAW_BLOCKSIZE 4096
+/* 64k are 128 x 512 byte sectors  */
+#define DASD_RAW_SECTORS_PER_TRACK 128
+
 MODULE_LICENSE("GPL");
 
 static struct dasd_discipline dasd_eckd_discipline;
@@ -385,6 +394,23 @@ static void fill_LRE_data(struct LRE_eckd_data *data, unsigned int trk,
                data->length = reclen;
                data->operation.operation = 0x03;
                break;
+       case DASD_ECKD_CCW_WRITE_FULL_TRACK:
+               data->operation.orientation = 0x0;
+               data->operation.operation = 0x3F;
+               data->extended_operation = 0x11;
+               data->length = 0;
+               data->extended_parameter_length = 0x02;
+               if (data->count > 8) {
+                       data->extended_parameter[0] = 0xFF;
+                       data->extended_parameter[1] = 0xFF;
+                       data->extended_parameter[1] <<= (16 - count);
+               } else {
+                       data->extended_parameter[0] = 0xFF;
+                       data->extended_parameter[0] <<= (8 - count);
+                       data->extended_parameter[1] = 0x00;
+               }
+               data->sector = 0xFF;
+               break;
        case DASD_ECKD_CCW_WRITE_TRACK_DATA:
                data->auxiliary.length_valid = 0x1;
                data->length = reclen;  /* not tlf, as one might think */
@@ -408,6 +434,12 @@ static void fill_LRE_data(struct LRE_eckd_data *data, unsigned int trk,
        case DASD_ECKD_CCW_READ_COUNT:
                data->operation.operation = 0x06;
                break;
+       case DASD_ECKD_CCW_READ_TRACK:
+               data->operation.orientation = 0x1;
+               data->operation.operation = 0x0C;
+               data->extended_parameter_length = 0;
+               data->sector = 0xFF;
+               break;
        case DASD_ECKD_CCW_READ_TRACK_DATA:
                data->auxiliary.length_valid = 0x1;
                data->length = tlf;
@@ -451,10 +483,16 @@ static int prefix_LRE(struct ccw1 *ccw, struct PFX_eckd_data *pfxdata,
 
        ccw->cmd_code = DASD_ECKD_CCW_PFX;
        ccw->flags = 0;
-       ccw->count = sizeof(*pfxdata);
-       ccw->cda = (__u32) __pa(pfxdata);
+       if (cmd == DASD_ECKD_CCW_WRITE_FULL_TRACK) {
+               ccw->count = sizeof(*pfxdata) + 2;
+               ccw->cda = (__u32) __pa(pfxdata);
+               memset(pfxdata, 0, sizeof(*pfxdata) + 2);
+       } else {
+               ccw->count = sizeof(*pfxdata);
+               ccw->cda = (__u32) __pa(pfxdata);
+               memset(pfxdata, 0, sizeof(*pfxdata));
+       }
 
-       memset(pfxdata, 0, sizeof(*pfxdata));
        /* prefix data */
        if (format > 1) {
                DBF_DEV_EVENT(DBF_ERR, basedev,
@@ -488,6 +526,7 @@ static int prefix_LRE(struct ccw1 *ccw, struct PFX_eckd_data *pfxdata,
                dedata->mask.perm = 0x1;
                dedata->attributes.operation = basepriv->attrib.operation;
                break;
+       case DASD_ECKD_CCW_READ_TRACK:
        case DASD_ECKD_CCW_READ_TRACK_DATA:
                dedata->mask.perm = 0x1;
                dedata->attributes.operation = basepriv->attrib.operation;
@@ -514,6 +553,11 @@ static int prefix_LRE(struct ccw1 *ccw, struct PFX_eckd_data *pfxdata,
                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;
@@ -1607,6 +1651,13 @@ static int dasd_eckd_end_analysis(struct dasd_block *block)
                dasd_sfree_request(init_cqr, device);
        }
 
+       if (device->features & DASD_FEATURE_USERAW) {
+               block->bp_block = DASD_RAW_BLOCKSIZE;
+               blk_per_trk = DASD_RAW_BLOCK_PER_TRACK;
+               block->s2b_shift = 3;
+               goto raw;
+       }
+
        if (status == INIT_CQR_UNFORMATTED) {
                dev_warn(&device->cdev->dev, "The DASD is not formatted\n");
                return -EMEDIUMTYPE;
@@ -1644,6 +1695,7 @@ static int dasd_eckd_end_analysis(struct dasd_block *block)
                        dev_warn(&device->cdev->dev,
                                 "Track 0 has no records following the VTOC\n");
        }
+
        if (count_area != NULL && count_area->kl == 0) {
                /* we found notthing violating our disk layout */
                if (dasd_check_blocksize(count_area->dl) == 0)
@@ -1659,6 +1711,8 @@ static int dasd_eckd_end_analysis(struct dasd_block *block)
                block->s2b_shift++;
 
        blk_per_trk = recs_per_track(&private->rdc_data, 0, block->bp_block);
+
+raw:
        block->blocks = (private->real_cyl *
                          private->rdc_data.trk_per_cyl *
                          blk_per_trk);
@@ -2741,6 +2795,135 @@ static struct dasd_ccw_req *dasd_eckd_build_cp(struct dasd_device *startdev,
        return cqr;
 }
 
+static struct dasd_ccw_req *dasd_raw_build_cp(struct dasd_device *startdev,
+                                              struct dasd_block *block,
+                                              struct request *req)
+{
+       struct dasd_eckd_private *private;
+       unsigned long *idaws;
+       struct dasd_device *basedev;
+       struct dasd_ccw_req *cqr;
+       struct ccw1 *ccw;
+       struct req_iterator iter;
+       struct bio_vec *bv;
+       char *dst;
+       unsigned char cmd;
+       unsigned int trkcount;
+       unsigned int seg_len, len_to_track_end;
+       unsigned int first_offs;
+       unsigned int cidaw, cplength, datasize;
+       sector_t first_trk, last_trk;
+       unsigned int pfx_datasize;
+
+       /*
+        * raw track access needs to be mutiple of 64k and on 64k boundary
+        */
+       if ((blk_rq_pos(req) % DASD_RAW_SECTORS_PER_TRACK) != 0) {
+               cqr = ERR_PTR(-EINVAL);
+               goto out;
+       }
+       if (((blk_rq_pos(req) + blk_rq_sectors(req)) %
+            DASD_RAW_SECTORS_PER_TRACK) != 0) {
+               cqr = ERR_PTR(-EINVAL);
+               goto out;
+       }
+
+       first_trk = blk_rq_pos(req) / DASD_RAW_SECTORS_PER_TRACK;
+       last_trk = (blk_rq_pos(req) + blk_rq_sectors(req) - 1) /
+               DASD_RAW_SECTORS_PER_TRACK;
+       trkcount = last_trk - first_trk + 1;
+       first_offs = 0;
+       basedev = block->base;
+       private = (struct dasd_eckd_private *) basedev->private;
+
+       if (rq_data_dir(req) == READ)
+               cmd = DASD_ECKD_CCW_READ_TRACK;
+       else if (rq_data_dir(req) == WRITE)
+               cmd = DASD_ECKD_CCW_WRITE_FULL_TRACK;
+       else {
+               cqr = ERR_PTR(-EINVAL);
+               goto out;
+       }
+
+       /*
+        * Raw track based I/O needs IDAWs for each page,
+        * and not just for 64 bit addresses.
+        */
+       cidaw = trkcount * DASD_RAW_BLOCK_PER_TRACK;
+
+       /* 1x prefix + one read/write ccw per track */
+       cplength = 1 + trkcount;
+
+       /*
+        * struct PFX_eckd_data has up to 2 byte as extended parameter
+        * this is needed for write full track and has to be mentioned
+        * seperately
+        * add 8 instead of 2 to keep 8 byte boundary
+        */
+       pfx_datasize = sizeof(struct PFX_eckd_data) + 8;
+
+       datasize = pfx_datasize + cidaw * sizeof(unsigned long long);
+
+       /* Allocate the ccw request. */
+       cqr = dasd_smalloc_request(DASD_ECKD_MAGIC, cplength,
+                                  datasize, startdev);
+       if (IS_ERR(cqr))
+               goto out;
+       ccw = cqr->cpaddr;
+
+       if (prefix_LRE(ccw++, cqr->data, first_trk, last_trk, cmd,
+                      basedev, startdev, 1 /* format */, first_offs + 1,
+                      trkcount, 0, 0) == -EAGAIN) {
+               /* Clock not in sync and XRC is enabled.
+                * Try again later.
+                */
+               dasd_sfree_request(cqr, startdev);
+               cqr = ERR_PTR(-EAGAIN);
+               goto out;
+       }
+
+       idaws = (unsigned long *)(cqr->data + pfx_datasize);
+
+       len_to_track_end = 0;
+
+       rq_for_each_segment(bv, req, iter) {
+               dst = page_address(bv->bv_page) + bv->bv_offset;
+               seg_len = bv->bv_len;
+               if (!len_to_track_end) {
+                       ccw[-1].flags |= CCW_FLAG_CC;
+                       ccw->cmd_code = cmd;
+                       /* maximum 3390 track size */
+                       ccw->count = 57326;
+                       /* 64k map to one track */
+                       len_to_track_end = 65536;
+                       ccw->cda = (__u32)(addr_t)idaws;
+                       ccw->flags |= CCW_FLAG_IDA;
+                       ccw->flags |= CCW_FLAG_SLI;
+                       ccw++;
+               }
+               len_to_track_end -= seg_len;
+               idaws = idal_create_words(idaws, dst, seg_len);
+       }
+
+       if (blk_noretry_request(req) ||
+           block->base->features & DASD_FEATURE_FAILFAST)
+               set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
+       cqr->startdev = startdev;
+       cqr->memdev = startdev;
+       cqr->block = block;
+       cqr->expires = startdev->default_expires * HZ;
+       cqr->lpm = startdev->path_data.ppm;
+       cqr->retries = 256;
+       cqr->buildclk = get_clock();
+       cqr->status = DASD_CQR_FILLED;
+
+       if (IS_ERR(cqr) && PTR_ERR(cqr) != -EAGAIN)
+               cqr = NULL;
+out:
+       return cqr;
+}
+
+
 static int
 dasd_eckd_free_cp(struct dasd_ccw_req *cqr, struct request *req)
 {
@@ -2845,7 +3028,10 @@ static struct dasd_ccw_req *dasd_eckd_build_alias_cp(struct dasd_device *base,
 
        spin_lock_irqsave(get_ccwdev_lock(startdev->cdev), flags);
        private->count++;
-       cqr = dasd_eckd_build_cp(startdev, block, req);
+       if ((base->features & DASD_FEATURE_USERAW))
+               cqr = dasd_raw_build_cp(startdev, block, req);
+       else
+               cqr = dasd_eckd_build_cp(startdev, block, req);
        if (IS_ERR(cqr))
                private->count--;
        spin_unlock_irqrestore(get_ccwdev_lock(startdev->cdev), flags);
index 5051f37..4a688a8 100644 (file)
 #define DASD_ECKD_CCW_WRITE_KD_MT       0x8d
 #define DASD_ECKD_CCW_READ_KD_MT        0x8e
 #define DASD_ECKD_CCW_RELEASE           0x94
+#define DASD_ECKD_CCW_WRITE_FULL_TRACK  0x95
 #define DASD_ECKD_CCW_READ_CKD_MT       0x9e
 #define DASD_ECKD_CCW_WRITE_CKD_MT      0x9d
 #define DASD_ECKD_CCW_WRITE_TRACK_DATA  0xA5
 #define DASD_ECKD_CCW_READ_TRACK_DATA   0xA6
 #define DASD_ECKD_CCW_RESERVE           0xB4
+#define DASD_ECKD_CCW_READ_TRACK        0xDE
 #define DASD_ECKD_CCW_PFX               0xE7
 #define DASD_ECKD_CCW_PFX_READ          0xEA
 #define DASD_ECKD_CCW_RSCK              0xF9