/* -*- linux-c -*- * viodasd.c * Authors: Dave Boutcher <boutcher@us.ibm.com> * Ryan Arnold <ryanarn@us.ibm.com> * Colin Devilbiss <devilbis@us.ibm.com> * Stephen Rothwell * * (C) Copyright 2000-2004 IBM Corporation * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * This routine provides access to disk space (termed "DASD" in historical * IBM terms) owned and managed by an OS/400 partition running on the * same box as this Linux partition. * * All disk operations are performed by sending messages back and forth to * the OS/400 partition. */ #define pr_fmt(fmt) "viod: " fmt #include <linux/major.h> #include <linux/fs.h> #include <linux/module.h> #include <linux/kernel.h> #include <linux/blkdev.h> #include <linux/genhd.h> #include <linux/hdreg.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/string.h> #include <linux/mutex.h> #include <linux/dma-mapping.h> #include <linux/completion.h> #include <linux/device.h> #include <linux/scatterlist.h> #include <asm/uaccess.h> #include <asm/vio.h> #include <asm/iseries/hv_types.h> #include <asm/iseries/hv_lp_event.h> #include <asm/iseries/hv_lp_config.h> #include <asm/iseries/vio.h> #include <asm/firmware.h> MODULE_DESCRIPTION("iSeries Virtual DASD"); MODULE_AUTHOR("Dave Boutcher"); MODULE_LICENSE("GPL"); /* * We only support 7 partitions per physical disk....so with minor * numbers 0-255 we get a maximum of 32 disks. */ #define VIOD_GENHD_NAME "iseries/vd" #define VIOD_VERS "1.64" enum { PARTITION_SHIFT = 3, MAX_DISKNO = HVMAXARCHITECTEDVIRTUALDISKS, MAX_DISK_NAME = FIELD_SIZEOF(struct gendisk, disk_name) }; static DEFINE_MUTEX(viodasd_mutex); static DEFINE_SPINLOCK(viodasd_spinlock); #define VIOMAXREQ 16 #define DEVICE_NO(cell) ((struct viodasd_device *)(cell) - &viodasd_devices[0]) struct viodasd_waitevent { struct completion com; int rc; u16 sub_result; int max_disk; /* open */ }; static const struct vio_error_entry viodasd_err_table[] = { { 0x0201, EINVAL, "Invalid Range" }, { 0x0202, EINVAL, "Invalid Token" }, { 0x0203, EIO, "DMA Error" }, { 0x0204, EIO, "Use Error" }, { 0x0205, EIO, "Release Error" }, { 0x0206, EINVAL, "Invalid Disk" }, { 0x0207, EBUSY, "Cant Lock" }, { 0x0208, EIO, "Already Locked" }, { 0x0209, EIO, "Already Unlocked" }, { 0x020A, EIO, "Invalid Arg" }, { 0x020B, EIO, "Bad IFS File" }, { 0x020C, EROFS, "Read Only Device" }, { 0x02FF, EIO, "Internal Error" }, { 0x0000, 0, NULL }, }; /* * Figure out the biggest I/O request (in sectors) we can accept */ #define VIODASD_MAXSECTORS (4096 / 512 * VIOMAXBLOCKDMA) /* * Number of disk I/O requests we've sent to OS/400 */ static int num_req_outstanding; /* * This is our internal structure for keeping track of disk devices */ struct viodasd_device { u16 cylinders; u16 tracks; u16 sectors; u16 bytes_per_sector; u64 size; int read_only; spinlock_t q_lock; struct gendisk *disk; struct device *dev; } viodasd_devices[MAX_DISKNO]; /* * External open entry point. */ static int viodasd_open(struct block_device *bdev, fmode_t mode) { struct viodasd_device *d = bdev->bd_disk->private_data; HvLpEvent_Rc hvrc; struct viodasd_waitevent we; u16 flags = 0; if (d->read_only) { if (mode & FMODE_WRITE) return -EROFS; flags = vioblockflags_ro; } init_completion(&we.com); /* Send the open event to OS/400 */ hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp, HvLpEvent_Type_VirtualIo, viomajorsubtype_blockio | vioblockopen, HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck, viopath_sourceinst(viopath_hostLp), viopath_targetinst(viopath_hostLp), (u64)(unsigned long)&we, VIOVERSION << 16, ((u64)DEVICE_NO(d) << 48) | ((u64)flags << 32), 0, 0, 0); if (hvrc != 0) { pr_warning("HV open failed %d\n", (int)hvrc); return -EIO; } wait_for_completion(&we.com); /* Check the return code */ if (we.rc != 0) { const struct vio_error_entry *err = vio_lookup_rc(viodasd_err_table, we.sub_result); pr_warning("bad rc opening disk: %d:0x%04x (%s)\n", (int)we.rc, we.sub_result, err->msg); return -EIO; } return 0; } static int viodasd_unlocked_open(struct block_device *bdev, fmode_t mode) { int ret; mutex_lock(&viodasd_mutex); ret = viodasd_open(bdev, mode); mutex_unlock(&viodasd_mutex); return ret; } /* * External release entry point. */ static int viodasd_release(struct gendisk *disk, fmode_t mode) { struct viodasd_device *d = disk->private_data; HvLpEvent_Rc hvrc; mutex_lock(&viodasd_mutex); /* Send the event to OS/400. We DON'T expect a response */ hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp, HvLpEvent_Type_VirtualIo, viomajorsubtype_blockio | vioblockclose, HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck, viopath_sourceinst(viopath_hostLp), viopath_targetinst(viopath_hostLp), 0, VIOVERSION << 16, ((u64)DEVICE_NO(d) << 48) /* | ((u64)flags << 32) */, 0, 0, 0); if (hvrc != 0) pr_warning("HV close call failed %d\n", (int)hvrc); mutex_unlock(&viodasd_mutex); return 0; } /* External ioctl entry point. */ static int viodasd_getgeo(struct block_device *bdev, struct hd_geometry *geo) { struct gendisk *disk = bdev->bd_disk; struct viodasd_device *d = disk->private_data; geo->sectors = d->sectors ? d->sectors : 32; geo->heads = d->tracks ? d->tracks : 64; geo->cylinders = d->cylinders ? d->cylinders : get_capacity(disk) / (geo->sectors * geo->heads); return 0; } /* * Our file operations table */ static const struct block_device_operations viodasd_fops = { .owner = THIS_MODULE, .open = viodasd_unlocked_open, .release = viodasd_release, .getgeo = viodasd_getgeo, }; /* * End a request */ static void viodasd_end_request(struct request *req, int error, int num_sectors) { __blk_end_request(req, error, num_sectors << 9); } /* * Send an actual I/O request to OS/400 */ static int send_request(struct request *req) { u64 start; int direction; int nsg; u16 viocmd; HvLpEvent_Rc hvrc; struct vioblocklpevent *bevent; struct HvLpEvent *hev; struct scatterlist sg[VIOMAXBLOCKDMA]; int sgindex; struct viodasd_device *d; unsigned long flags; start = (u64)blk_rq_pos(req) << 9; if (rq_data_dir(req) == READ) { direction = DMA_FROM_DEVICE; viocmd = viomajorsubtype_blockio | vioblockread; } else { direction = DMA_TO_DEVICE; viocmd = viomajorsubtype_blockio | vioblockwrite; } d = req->rq_disk->private_data; /* Now build the scatter-gather list */ sg_init_table(sg, VIOMAXBLOCKDMA); nsg = blk_rq_map_sg(req->q, req, sg); nsg = dma_map_sg(d->dev, sg, nsg, direction); spin_lock_irqsave(&viodasd_spinlock, flags); num_req_outstanding++; /* This optimization handles a single DMA block */ if (nsg == 1) hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp, HvLpEvent_Type_VirtualIo, viocmd, HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck, viopath_sourceinst(viopath_hostLp), viopath_targetinst(viopath_hostLp), (u64)(unsigned long)req, VIOVERSION << 16, ((u64)DEVICE_NO(d) << 48), start, ((u64)sg_dma_address(&sg[0])) << 32, sg_dma_len(&sg[0])); else { bevent = (struct vioblocklpevent *) vio_get_event_buffer(viomajorsubtype_blockio); if (bevent == NULL) { pr_warning("error allocating disk event buffer\n"); goto error_ret; } /* * Now build up the actual request. Note that we store * the pointer to the request in the correlation * token so we can match the response up later */ memset(bevent, 0, sizeof(struct vioblocklpevent)); hev = &bevent->event; hev->flags = HV_LP_EVENT_VALID | HV_LP_EVENT_DO_ACK | HV_LP_EVENT_INT; hev->xType = HvLpEvent_Type_VirtualIo; hev->xSubtype = viocmd; hev->xSourceLp = HvLpConfig_getLpIndex(); hev->xTargetLp = viopath_hostLp; hev->xSizeMinus1 = offsetof(struct vioblocklpevent, u.rw_data.dma_info) + (sizeof(bevent->u.rw_data.dma_info[0]) * nsg) - 1; hev->xSourceInstanceId = viopath_sourceinst(viopath_hostLp); hev->xTargetInstanceId = viopath_targetinst(viopath_hostLp); hev->xCorrelationToken = (u64)req; bevent->version = VIOVERSION; bevent->disk = DEVICE_NO(d); bevent->u.rw_data.offset = start; /* * Copy just the dma information from the sg list * into the request */ for (sgindex = 0; sgindex < nsg; sgindex++) { bevent->u.rw_data.dma_info[sgindex].token = sg_dma_address(&sg[sgindex]); bevent->u.rw_data.dma_info[sgindex].len = sg_dma_len(&sg[sgindex]); } /* Send the request */ hvrc = HvCallEvent_signalLpEvent(&bevent->event); vio_free_event_buffer(viomajorsubtype_blockio, bevent); } if (hvrc != HvLpEvent_Rc_Good) { pr_warning("error sending disk event to OS/400 (rc %d)\n", (int)hvrc); goto error_ret; } spin_unlock_irqrestore(&viodasd_spinlock, flags); return 0; error_ret: num_req_outstanding--; spin_unlock_irqrestore(&viodasd_spinlock, flags); dma_unmap_sg(d->dev, sg, nsg, direction); return -1; } /* * This is the external request processing routine */ static void do_viodasd_request(struct request_queue *q) { struct request *req; /* * If we already have the maximum number of requests * outstanding to OS/400 just bail out. We'll come * back later. */ while (num_req_outstanding < VIOMAXREQ) { req = blk_fetch_request(q); if (req == NULL) return; /* check that request contains a valid command */ if (req->cmd_type != REQ_TYPE_FS) { viodasd_end_request(req, -EIO, blk_rq_sectors(req)); continue; } /* Try sending the request */ if (send_request(req) != 0) viodasd_end_request(req, -EIO, blk_rq_sectors(req)); } } /* * Probe a single disk and fill in the viodasd_device structure * for it. */ static int probe_disk(struct viodasd_device *d) { HvLpEvent_Rc hvrc; struct viodasd_waitevent we; int dev_no = DEVICE_NO(d); struct gendisk *g; struct request_queue *q; u16 flags = 0; retry: init_completion(&we.com); /* Send the open event to OS/400 */ hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp, HvLpEvent_Type_VirtualIo, viomajorsubtype_blockio | vioblockopen, HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck, viopath_sourceinst(viopath_hostLp), viopath_targetinst(viopath_hostLp), (u64)(unsigned long)&we, VIOVERSION << 16, ((u64)dev_no << 48) | ((u64)flags<< 32), 0, 0, 0); if (hvrc != 0) { pr_warning("bad rc on HV open %d\n", (int)hvrc); return 0; } wait_for_completion(&we.com); if (we.rc != 0) { if (flags != 0) return 0; /* try again with read only flag set */ flags = vioblockflags_ro; goto retry; } if (we.max_disk > (MAX_DISKNO - 1)) { printk_once(KERN_INFO pr_fmt("Only examining the first %d of %d disks connected\n"), MAX_DISKNO, we.max_disk + 1); } /* Send the close event to OS/400. We DON'T expect a response */ hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp, HvLpEvent_Type_VirtualIo, viomajorsubtype_blockio | vioblockclose, HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck, viopath_sourceinst(viopath_hostLp), viopath_targetinst(viopath_hostLp), 0, VIOVERSION << 16, ((u64)dev_no << 48) | ((u64)flags << 32), 0, 0, 0); if (hvrc != 0) { pr_warning("bad rc sending event to OS/400 %d\n", (int)hvrc); return 0; } if (d->dev == NULL) { /* this is when we reprobe for new disks */ if (vio_create_viodasd(dev_no) == NULL) { pr_warning("cannot allocate virtual device for disk %d\n", dev_no); return 0; } /* * The vio_create_viodasd will have recursed into this * routine with d->dev set to the new vio device and * will finish the setup of the disk below. */ return 1; } /* create the request queue for the disk */ spin_lock_init(&d->q_lock); q = blk_init_queue(do_viodasd_request, &d->q_lock); if (q == NULL) { pr_warning("cannot allocate queue for disk %d\n", dev_no); return 0; } g = alloc_disk(1 << PARTITION_SHIFT); if (g == NULL) { pr_warning("cannot allocate disk structure for disk %d\n", dev_no); blk_cleanup_queue(q); return 0; } d->disk = g; blk_queue_max_segments(q, VIOMAXBLOCKDMA); blk_queue_max_hw_sectors(q, VIODASD_MAXSECTORS); g->major = VIODASD_MAJOR; g->first_minor = dev_no << PARTITION_SHIFT; if (dev_no >= 26) snprintf(g->disk_name, sizeof(g->disk_name), VIOD_GENHD_NAME "%c%c", 'a' + (dev_no / 26) - 1, 'a' + (dev_no % 26)); else snprintf(g->disk_name, sizeof(g->disk_name), VIOD_GENHD_NAME "%c", 'a' + (dev_no % 26)); g->fops = &viodasd_fops; g->queue = q; g->private_data = d; g->driverfs_dev = d->dev; set_capacity(g, d->size >> 9); pr_info("disk %d: %lu sectors (%lu MB) CHS=%d/%d/%d sector size %d%s\n", dev_no, (unsigned long)(d->size >> 9), (unsigned long)(d->size >> 20), (int)d->cylinders, (int)d->tracks, (int)d->sectors, (int)d->bytes_per_sector, d->read_only ? " (RO)" : ""); /* register us in the global list */ add_disk(g); return 1; } /* returns the total number of scatterlist elements converted */ static int block_event_to_scatterlist(const struct vioblocklpevent *bevent, struct scatterlist *sg, int *total_len) { int i, numsg; const struct rw_data *rw_data = &bevent->u.rw_data; static const int offset = offsetof(struct vioblocklpevent, u.rw_data.dma_info); static const int element_size = sizeof(rw_data->dma_info[0]); numsg = ((bevent->event.xSizeMinus1 + 1) - offset) / element_size; if (numsg > VIOMAXBLOCKDMA) numsg = VIOMAXBLOCKDMA; *total_len = 0; sg_init_table(sg, VIOMAXBLOCKDMA); for (i = 0; (i < numsg) && (rw_data->dma_info[i].len > 0); ++i) { sg_dma_address(&sg[i]) = rw_data->dma_info[i].token; sg_dma_len(&sg[i]) = rw_data->dma_info[i].len; *total_len += rw_data->dma_info[i].len; } return i; } /* * Restart all queues, starting with the one _after_ the disk given, * thus reducing the chance of starvation of higher numbered disks. */ static void viodasd_restart_all_queues_starting_from(int first_index) { int i; for (i = first_index + 1; i < MAX_DISKNO; ++i) if (viodasd_devices[i].disk) blk_run_queue(viodasd_devices[i].disk->queue); for (i = 0; i <= first_index; ++i) if (viodasd_devices[i].disk) blk_run_queue(viodasd_devices[i].disk->queue); } /* * For read and write requests, decrement the number of outstanding requests, * Free the DMA buffers we allocated. */ static int viodasd_handle_read_write(struct vioblocklpevent *bevent) { int num_sg, num_sect, pci_direction, total_len; struct request *req; struct scatterlist sg[VIOMAXBLOCKDMA]; struct HvLpEvent *event = &bevent->event; unsigned long irq_flags; struct viodasd_device *d; int error; spinlock_t *qlock; num_sg = block_event_to_scatterlist(bevent, sg, &total_len); num_sect = total_len >> 9; if (event->xSubtype == (viomajorsubtype_blockio | vioblockread)) pci_direction = DMA_FROM_DEVICE; else pci_direction = DMA_TO_DEVICE; req = (struct request *)bevent->event.xCorrelationToken; d = req->rq_disk->private_data; dma_unmap_sg(d->dev, sg, num_sg, pci_direction); /* * Since this is running in interrupt mode, we need to make sure * we're not stepping on any global I/O operations */ spin_lock_irqsave(&viodasd_spinlock, irq_flags); num_req_outstanding--; spin_unlock_irqrestore(&viodasd_spinlock, irq_flags); error = (event->xRc == HvLpEvent_Rc_Good) ? 0 : -EIO; if (error) { const struct vio_error_entry *err; err = vio_lookup_rc(viodasd_err_table, bevent->sub_result); pr_warning("read/write error %d:0x%04x (%s)\n", event->xRc, bevent->sub_result, err->msg); num_sect = blk_rq_sectors(req); } qlock = req->q->queue_lock; spin_lock_irqsave(qlock, irq_flags); viodasd_end_request(req, error, num_sect); spin_unlock_irqrestore(qlock, irq_flags); /* Finally, try to get more requests off of this device's queue */ viodasd_restart_all_queues_starting_from(DEVICE_NO(d)); return 0; } /* This routine handles incoming block LP events */ static void handle_block_event(struct HvLpEvent *event) { struct vioblocklpevent *bevent = (struct vioblocklpevent *)event; struct viodasd_waitevent *pwe; if (event == NULL) /* Notification that a partition went away! */ return; /* First, we should NEVER get an int here...only acks */ if (hvlpevent_is_int(event)) { pr_warning("Yikes! got an int in viodasd event handler!\n"); if (hvlpevent_need_ack(event)) { event->xRc = HvLpEvent_Rc_InvalidSubtype; HvCallEvent_ackLpEvent(event); } } switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) { case vioblockopen: /* * Handle a response to an open request. We get all the * disk information in the response, so update it. The * correlation token contains a pointer to a waitevent * structure that has a completion in it. update the * return code in the waitevent structure and post the * completion to wake up the guy who sent the request */ pwe = (struct viodasd_waitevent *)event->xCorrelationToken; pwe->rc = event->xRc; pwe->sub_result = bevent->sub_result; if (event->xRc == HvLpEvent_Rc_Good) { const struct open_data *data = &bevent->u.open_data; struct viodasd_device *device = &viodasd_devices[bevent->disk]; device->read_only = bevent->flags & vioblockflags_ro; device->size = data->disk_size; device->cylinders = data->cylinders; device->tracks = data->tracks; device->sectors = data->sectors; device->bytes_per_sector = data->bytes_per_sector; pwe->max_disk = data->max_disk; } complete(&pwe->com); break; case vioblockclose: break; case vioblockread: case vioblockwrite: viodasd_handle_read_write(bevent); break; default: pr_warning("invalid subtype!"); if (hvlpevent_need_ack(event)) { event->xRc = HvLpEvent_Rc_InvalidSubtype; HvCallEvent_ackLpEvent(event); } } } /* * Get the driver to reprobe for more disks. */ static ssize_t probe_disks(struct device_driver *drv, const char *buf, size_t count) { struct viodasd_device *d; for (d = viodasd_devices; d < &viodasd_devices[MAX_DISKNO]; d++) { if (d->disk == NULL) probe_disk(d); } return count; } static DRIVER_ATTR(probe, S_IWUSR, NULL, probe_disks); static int viodasd_probe(struct vio_dev *vdev, const struct vio_device_id *id) { struct viodasd_device *d = &viodasd_devices[vdev->unit_address]; d->dev = &vdev->dev; if (!probe_disk(d)) return -ENODEV; return 0; } static int viodasd_remove(struct vio_dev *vdev) { struct viodasd_device *d; d = &viodasd_devices[vdev->unit_address]; if (d->disk) { del_gendisk(d->disk); blk_cleanup_queue(d->disk->queue); put_disk(d->disk); d->disk = NULL; } d->dev = NULL; return 0; } /** * viodasd_device_table: Used by vio.c to match devices that we * support. */ static struct vio_device_id viodasd_device_table[] __devinitdata = { { "block", "IBM,iSeries-viodasd" }, { "", "" } }; MODULE_DEVICE_TABLE(vio, viodasd_device_table); static struct vio_driver viodasd_driver = { .id_table = viodasd_device_table, .probe = viodasd_probe, .remove = viodasd_remove, .driver = { .name = "viodasd", .owner = THIS_MODULE, } }; static int need_delete_probe; /* * Initialize the whole device driver. Handle module and non-module * versions */ static int __init viodasd_init(void) { int rc; if (!firmware_has_feature(FW_FEATURE_ISERIES)) { rc = -ENODEV; goto early_fail; } /* Try to open to our host lp */ if (viopath_hostLp == HvLpIndexInvalid) vio_set_hostlp(); if (viopath_hostLp == HvLpIndexInvalid) { pr_warning("invalid hosting partition\n"); rc = -EIO; goto early_fail; } pr_info("vers " VIOD_VERS ", hosting partition %d\n", viopath_hostLp); /* register the block device */ rc = register_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME); if (rc) { pr_warning("Unable to get major number %d for %s\n", VIODASD_MAJOR, VIOD_GENHD_NAME); goto early_fail; } /* Actually open the path to the hosting partition */ rc = viopath_open(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2); if (rc) { pr_warning("error opening path to host partition %d\n", viopath_hostLp); goto unregister_blk; } /* Initialize our request handler */ vio_setHandler(viomajorsubtype_blockio, handle_block_event); rc = vio_register_driver(&viodasd_driver); if (rc) { pr_warning("vio_register_driver failed\n"); goto unset_handler; } /* * If this call fails, it just means that we cannot dynamically * add virtual disks, but the driver will still work fine for * all existing disk, so ignore the failure. */ if (!driver_create_file(&viodasd_driver.driver, &driver_attr_probe)) need_delete_probe = 1; return 0; unset_handler: vio_clearHandler(viomajorsubtype_blockio); viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2); unregister_blk: unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME); early_fail: return rc; } module_init(viodasd_init); void __exit viodasd_exit(void) { if (need_delete_probe) driver_remove_file(&viodasd_driver.driver, &driver_attr_probe); vio_unregister_driver(&viodasd_driver); vio_clearHandler(viomajorsubtype_blockio); viopath_close(viopath_hostLp, viomajorsubtype_blockio, VIOMAXREQ + 2); unregister_blkdev(VIODASD_MAJOR, VIOD_GENHD_NAME); } module_exit(viodasd_exit);