/* sunvdc.c: Sun LDOM Virtual Disk Client. * * Copyright (C) 2007 David S. Miller <davem@davemloft.net> */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/types.h> #include <linux/blkdev.h> #include <linux/hdreg.h> #include <linux/genhd.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/completion.h> #include <linux/delay.h> #include <linux/init.h> #include <linux/list.h> #include <linux/scatterlist.h> #include <asm/vio.h> #include <asm/ldc.h> #define DRV_MODULE_NAME "sunvdc" #define PFX DRV_MODULE_NAME ": " #define DRV_MODULE_VERSION "1.0" #define DRV_MODULE_RELDATE "June 25, 2007" static char version[] __devinitdata = DRV_MODULE_NAME ".c:v" DRV_MODULE_VERSION " (" DRV_MODULE_RELDATE ")\n"; MODULE_AUTHOR("David S. Miller (davem@davemloft.net)"); MODULE_DESCRIPTION("Sun LDOM virtual disk client driver"); MODULE_LICENSE("GPL"); MODULE_VERSION(DRV_MODULE_VERSION); #define VDC_TX_RING_SIZE 256 #define WAITING_FOR_LINK_UP 0x01 #define WAITING_FOR_TX_SPACE 0x02 #define WAITING_FOR_GEN_CMD 0x04 #define WAITING_FOR_ANY -1 struct vdc_req_entry { struct request *req; }; struct vdc_port { struct vio_driver_state vio; struct gendisk *disk; struct vdc_completion *cmp; u64 req_id; u64 seq; struct vdc_req_entry rq_arr[VDC_TX_RING_SIZE]; unsigned long ring_cookies; u64 max_xfer_size; u32 vdisk_block_size; /* The server fills these in for us in the disk attribute * ACK packet. */ u64 operations; u32 vdisk_size; u8 vdisk_type; char disk_name[32]; struct vio_disk_geom geom; struct vio_disk_vtoc label; }; static inline struct vdc_port *to_vdc_port(struct vio_driver_state *vio) { return container_of(vio, struct vdc_port, vio); } /* Ordered from largest major to lowest */ static struct vio_version vdc_versions[] = { { .major = 1, .minor = 0 }, }; #define VDCBLK_NAME "vdisk" static int vdc_major; #define PARTITION_SHIFT 3 static inline u32 vdc_tx_dring_avail(struct vio_dring_state *dr) { return vio_dring_avail(dr, VDC_TX_RING_SIZE); } static int vdc_getgeo(struct block_device *bdev, struct hd_geometry *geo) { struct gendisk *disk = bdev->bd_disk; struct vdc_port *port = disk->private_data; geo->heads = (u8) port->geom.num_hd; geo->sectors = (u8) port->geom.num_sec; geo->cylinders = port->geom.num_cyl; return 0; } static struct block_device_operations vdc_fops = { .owner = THIS_MODULE, .getgeo = vdc_getgeo, }; static void vdc_finish(struct vio_driver_state *vio, int err, int waiting_for) { if (vio->cmp && (waiting_for == -1 || vio->cmp->waiting_for == waiting_for)) { vio->cmp->err = err; complete(&vio->cmp->com); vio->cmp = NULL; } } static void vdc_handshake_complete(struct vio_driver_state *vio) { vdc_finish(vio, 0, WAITING_FOR_LINK_UP); } static int vdc_handle_unknown(struct vdc_port *port, void *arg) { struct vio_msg_tag *pkt = arg; printk(KERN_ERR PFX "Received unknown msg [%02x:%02x:%04x:%08x]\n", pkt->type, pkt->stype, pkt->stype_env, pkt->sid); printk(KERN_ERR PFX "Resetting connection.\n"); ldc_disconnect(port->vio.lp); return -ECONNRESET; } static int vdc_send_attr(struct vio_driver_state *vio) { struct vdc_port *port = to_vdc_port(vio); struct vio_disk_attr_info pkt; memset(&pkt, 0, sizeof(pkt)); pkt.tag.type = VIO_TYPE_CTRL; pkt.tag.stype = VIO_SUBTYPE_INFO; pkt.tag.stype_env = VIO_ATTR_INFO; pkt.tag.sid = vio_send_sid(vio); pkt.xfer_mode = VIO_DRING_MODE; pkt.vdisk_block_size = port->vdisk_block_size; pkt.max_xfer_size = port->max_xfer_size; viodbg(HS, "SEND ATTR xfer_mode[0x%x] blksz[%u] max_xfer[%lu]\n", pkt.xfer_mode, pkt.vdisk_block_size, pkt.max_xfer_size); return vio_ldc_send(&port->vio, &pkt, sizeof(pkt)); } static int vdc_handle_attr(struct vio_driver_state *vio, void *arg) { struct vdc_port *port = to_vdc_port(vio); struct vio_disk_attr_info *pkt = arg; viodbg(HS, "GOT ATTR stype[0x%x] ops[%lx] disk_size[%lu] disk_type[%x] " "xfer_mode[0x%x] blksz[%u] max_xfer[%lu]\n", pkt->tag.stype, pkt->operations, pkt->vdisk_size, pkt->vdisk_type, pkt->xfer_mode, pkt->vdisk_block_size, pkt->max_xfer_size); if (pkt->tag.stype == VIO_SUBTYPE_ACK) { switch (pkt->vdisk_type) { case VD_DISK_TYPE_DISK: case VD_DISK_TYPE_SLICE: break; default: printk(KERN_ERR PFX "%s: Bogus vdisk_type 0x%x\n", vio->name, pkt->vdisk_type); return -ECONNRESET; } if (pkt->vdisk_block_size > port->vdisk_block_size) { printk(KERN_ERR PFX "%s: BLOCK size increased " "%u --> %u\n", vio->name, port->vdisk_block_size, pkt->vdisk_block_size); return -ECONNRESET; } port->operations = pkt->operations; port->vdisk_size = pkt->vdisk_size; port->vdisk_type = pkt->vdisk_type; if (pkt->max_xfer_size < port->max_xfer_size) port->max_xfer_size = pkt->max_xfer_size; port->vdisk_block_size = pkt->vdisk_block_size; return 0; } else { printk(KERN_ERR PFX "%s: Attribute NACK\n", vio->name); return -ECONNRESET; } } static void vdc_end_special(struct vdc_port *port, struct vio_disk_desc *desc) { int err = desc->status; vdc_finish(&port->vio, -err, WAITING_FOR_GEN_CMD); } static void vdc_end_request(struct request *req, int error, int num_sectors) { __blk_end_request(req, error, num_sectors << 9); } static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr, unsigned int index) { struct vio_disk_desc *desc = vio_dring_entry(dr, index); struct vdc_req_entry *rqe = &port->rq_arr[index]; struct request *req; if (unlikely(desc->hdr.state != VIO_DESC_DONE)) return; ldc_unmap(port->vio.lp, desc->cookies, desc->ncookies); desc->hdr.state = VIO_DESC_FREE; dr->cons = (index + 1) & (VDC_TX_RING_SIZE - 1); req = rqe->req; if (req == NULL) { vdc_end_special(port, desc); return; } rqe->req = NULL; vdc_end_request(req, (desc->status ? -EIO : 0), desc->size >> 9); if (blk_queue_stopped(port->disk->queue)) blk_start_queue(port->disk->queue); } static int vdc_ack(struct vdc_port *port, void *msgbuf) { struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING]; struct vio_dring_data *pkt = msgbuf; if (unlikely(pkt->dring_ident != dr->ident || pkt->start_idx != pkt->end_idx || pkt->start_idx >= VDC_TX_RING_SIZE)) return 0; vdc_end_one(port, dr, pkt->start_idx); return 0; } static int vdc_nack(struct vdc_port *port, void *msgbuf) { /* XXX Implement me XXX */ return 0; } static void vdc_event(void *arg, int event) { struct vdc_port *port = arg; struct vio_driver_state *vio = &port->vio; unsigned long flags; int err; spin_lock_irqsave(&vio->lock, flags); if (unlikely(event == LDC_EVENT_RESET || event == LDC_EVENT_UP)) { vio_link_state_change(vio, event); spin_unlock_irqrestore(&vio->lock, flags); return; } if (unlikely(event != LDC_EVENT_DATA_READY)) { printk(KERN_WARNING PFX "Unexpected LDC event %d\n", event); spin_unlock_irqrestore(&vio->lock, flags); return; } err = 0; while (1) { union { struct vio_msg_tag tag; u64 raw[8]; } msgbuf; err = ldc_read(vio->lp, &msgbuf, sizeof(msgbuf)); if (unlikely(err < 0)) { if (err == -ECONNRESET) vio_conn_reset(vio); break; } if (err == 0) break; viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n", msgbuf.tag.type, msgbuf.tag.stype, msgbuf.tag.stype_env, msgbuf.tag.sid); err = vio_validate_sid(vio, &msgbuf.tag); if (err < 0) break; if (likely(msgbuf.tag.type == VIO_TYPE_DATA)) { if (msgbuf.tag.stype == VIO_SUBTYPE_ACK) err = vdc_ack(port, &msgbuf); else if (msgbuf.tag.stype == VIO_SUBTYPE_NACK) err = vdc_nack(port, &msgbuf); else err = vdc_handle_unknown(port, &msgbuf); } else if (msgbuf.tag.type == VIO_TYPE_CTRL) { err = vio_control_pkt_engine(vio, &msgbuf); } else { err = vdc_handle_unknown(port, &msgbuf); } if (err < 0) break; } if (err < 0) vdc_finish(&port->vio, err, WAITING_FOR_ANY); spin_unlock_irqrestore(&vio->lock, flags); } static int __vdc_tx_trigger(struct vdc_port *port) { struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING]; struct vio_dring_data hdr = { .tag = { .type = VIO_TYPE_DATA, .stype = VIO_SUBTYPE_INFO, .stype_env = VIO_DRING_DATA, .sid = vio_send_sid(&port->vio), }, .dring_ident = dr->ident, .start_idx = dr->prod, .end_idx = dr->prod, }; int err, delay; hdr.seq = dr->snd_nxt; delay = 1; do { err = vio_ldc_send(&port->vio, &hdr, sizeof(hdr)); if (err > 0) { dr->snd_nxt++; break; } udelay(delay); if ((delay <<= 1) > 128) delay = 128; } while (err == -EAGAIN); return err; } static int __send_request(struct request *req) { struct vdc_port *port = req->rq_disk->private_data; struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING]; struct scatterlist sg[port->ring_cookies]; struct vdc_req_entry *rqe; struct vio_disk_desc *desc; unsigned int map_perm; int nsg, err, i; u64 len; u8 op; map_perm = LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO; if (rq_data_dir(req) == READ) { map_perm |= LDC_MAP_W; op = VD_OP_BREAD; } else { map_perm |= LDC_MAP_R; op = VD_OP_BWRITE; } sg_init_table(sg, port->ring_cookies); nsg = blk_rq_map_sg(req->q, req, sg); len = 0; for (i = 0; i < nsg; i++) len += sg[i].length; if (unlikely(vdc_tx_dring_avail(dr) < 1)) { blk_stop_queue(port->disk->queue); err = -ENOMEM; goto out; } desc = vio_dring_cur(dr); err = ldc_map_sg(port->vio.lp, sg, nsg, desc->cookies, port->ring_cookies, map_perm); if (err < 0) { printk(KERN_ERR PFX "ldc_map_sg() failure, err=%d.\n", err); return err; } rqe = &port->rq_arr[dr->prod]; rqe->req = req; desc->hdr.ack = VIO_ACK_ENABLE; desc->req_id = port->req_id; desc->operation = op; if (port->vdisk_type == VD_DISK_TYPE_DISK) { desc->slice = 0xff; } else { desc->slice = 0; } desc->status = ~0; desc->offset = (req->sector << 9) / port->vdisk_block_size; desc->size = len; desc->ncookies = err; /* This has to be a non-SMP write barrier because we are writing * to memory which is shared with the peer LDOM. */ wmb(); desc->hdr.state = VIO_DESC_READY; err = __vdc_tx_trigger(port); if (err < 0) { printk(KERN_ERR PFX "vdc_tx_trigger() failure, err=%d\n", err); } else { port->req_id++; dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1); } out: return err; } static void do_vdc_request(struct request_queue *q) { while (1) { struct request *req = elv_next_request(q); if (!req) break; blkdev_dequeue_request(req); if (__send_request(req) < 0) vdc_end_request(req, -EIO, req->hard_nr_sectors); } } static int generic_request(struct vdc_port *port, u8 op, void *buf, int len) { struct vio_dring_state *dr; struct vio_completion comp; struct vio_disk_desc *desc; unsigned int map_perm; unsigned long flags; int op_len, err; void *req_buf; if (!(((u64)1 << ((u64)op - 1)) & port->operations)) return -EOPNOTSUPP; switch (op) { case VD_OP_BREAD: case VD_OP_BWRITE: default: return -EINVAL; case VD_OP_FLUSH: op_len = 0; map_perm = 0; break; case VD_OP_GET_WCE: op_len = sizeof(u32); map_perm = LDC_MAP_W; break; case VD_OP_SET_WCE: op_len = sizeof(u32); map_perm = LDC_MAP_R; break; case VD_OP_GET_VTOC: op_len = sizeof(struct vio_disk_vtoc); map_perm = LDC_MAP_W; break; case VD_OP_SET_VTOC: op_len = sizeof(struct vio_disk_vtoc); map_perm = LDC_MAP_R; break; case VD_OP_GET_DISKGEOM: op_len = sizeof(struct vio_disk_geom); map_perm = LDC_MAP_W; break; case VD_OP_SET_DISKGEOM: op_len = sizeof(struct vio_disk_geom); map_perm = LDC_MAP_R; break; case VD_OP_SCSICMD: op_len = 16; map_perm = LDC_MAP_RW; break; case VD_OP_GET_DEVID: op_len = sizeof(struct vio_disk_devid); map_perm = LDC_MAP_W; break; case VD_OP_GET_EFI: case VD_OP_SET_EFI: return -EOPNOTSUPP; break; }; map_perm |= LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_IO; op_len = (op_len + 7) & ~7; req_buf = kzalloc(op_len, GFP_KERNEL); if (!req_buf) return -ENOMEM; if (len > op_len) len = op_len; if (map_perm & LDC_MAP_R) memcpy(req_buf, buf, len); spin_lock_irqsave(&port->vio.lock, flags); dr = &port->vio.drings[VIO_DRIVER_TX_RING]; /* XXX If we want to use this code generically we have to * XXX handle TX ring exhaustion etc. */ desc = vio_dring_cur(dr); err = ldc_map_single(port->vio.lp, req_buf, op_len, desc->cookies, port->ring_cookies, map_perm); if (err < 0) { spin_unlock_irqrestore(&port->vio.lock, flags); kfree(req_buf); return err; } init_completion(&comp.com); comp.waiting_for = WAITING_FOR_GEN_CMD; port->vio.cmp = ∁ desc->hdr.ack = VIO_ACK_ENABLE; desc->req_id = port->req_id; desc->operation = op; desc->slice = 0; desc->status = ~0; desc->offset = 0; desc->size = op_len; desc->ncookies = err; /* This has to be a non-SMP write barrier because we are writing * to memory which is shared with the peer LDOM. */ wmb(); desc->hdr.state = VIO_DESC_READY; err = __vdc_tx_trigger(port); if (err >= 0) { port->req_id++; dr->prod = (dr->prod + 1) & (VDC_TX_RING_SIZE - 1); spin_unlock_irqrestore(&port->vio.lock, flags); wait_for_completion(&comp.com); err = comp.err; } else { port->vio.cmp = NULL; spin_unlock_irqrestore(&port->vio.lock, flags); } if (map_perm & LDC_MAP_W) memcpy(buf, req_buf, len); kfree(req_buf); return err; } static int __devinit vdc_alloc_tx_ring(struct vdc_port *port) { struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING]; unsigned long len, entry_size; int ncookies; void *dring; entry_size = sizeof(struct vio_disk_desc) + (sizeof(struct ldc_trans_cookie) * port->ring_cookies); len = (VDC_TX_RING_SIZE * entry_size); ncookies = VIO_MAX_RING_COOKIES; dring = ldc_alloc_exp_dring(port->vio.lp, len, dr->cookies, &ncookies, (LDC_MAP_SHADOW | LDC_MAP_DIRECT | LDC_MAP_RW)); if (IS_ERR(dring)) return PTR_ERR(dring); dr->base = dring; dr->entry_size = entry_size; dr->num_entries = VDC_TX_RING_SIZE; dr->prod = dr->cons = 0; dr->pending = VDC_TX_RING_SIZE; dr->ncookies = ncookies; return 0; } static void vdc_free_tx_ring(struct vdc_port *port) { struct vio_dring_state *dr = &port->vio.drings[VIO_DRIVER_TX_RING]; if (dr->base) { ldc_free_exp_dring(port->vio.lp, dr->base, (dr->entry_size * dr->num_entries), dr->cookies, dr->ncookies); dr->base = NULL; dr->entry_size = 0; dr->num_entries = 0; dr->pending = 0; dr->ncookies = 0; } } static int probe_disk(struct vdc_port *port) { struct vio_completion comp; struct request_queue *q; struct gendisk *g; int err; init_completion(&comp.com); comp.err = 0; comp.waiting_for = WAITING_FOR_LINK_UP; port->vio.cmp = ∁ vio_port_up(&port->vio); wait_for_completion(&comp.com); if (comp.err) return comp.err; err = generic_request(port, VD_OP_GET_VTOC, &port->label, sizeof(port->label)); if (err < 0) { printk(KERN_ERR PFX "VD_OP_GET_VTOC returns error %d\n", err); return err; } err = generic_request(port, VD_OP_GET_DISKGEOM, &port->geom, sizeof(port->geom)); if (err < 0) { printk(KERN_ERR PFX "VD_OP_GET_DISKGEOM returns " "error %d\n", err); return err; } port->vdisk_size = ((u64)port->geom.num_cyl * (u64)port->geom.num_hd * (u64)port->geom.num_sec); q = blk_init_queue(do_vdc_request, &port->vio.lock); if (!q) { printk(KERN_ERR PFX "%s: Could not allocate queue.\n", port->vio.name); return -ENOMEM; } g = alloc_disk(1 << PARTITION_SHIFT); if (!g) { printk(KERN_ERR PFX "%s: Could not allocate gendisk.\n", port->vio.name); blk_cleanup_queue(q); return -ENOMEM; } port->disk = g; blk_queue_max_hw_segments(q, port->ring_cookies); blk_queue_max_phys_segments(q, port->ring_cookies); blk_queue_max_sectors(q, port->max_xfer_size); g->major = vdc_major; g->first_minor = port->vio.vdev->dev_no << PARTITION_SHIFT; strcpy(g->disk_name, port->disk_name); g->fops = &vdc_fops; g->queue = q; g->private_data = port; g->driverfs_dev = &port->vio.vdev->dev; set_capacity(g, port->vdisk_size); printk(KERN_INFO PFX "%s: %u sectors (%u MB)\n", g->disk_name, port->vdisk_size, (port->vdisk_size >> (20 - 9))); add_disk(g); return 0; } static struct ldc_channel_config vdc_ldc_cfg = { .event = vdc_event, .mtu = 64, .mode = LDC_MODE_UNRELIABLE, }; static struct vio_driver_ops vdc_vio_ops = { .send_attr = vdc_send_attr, .handle_attr = vdc_handle_attr, .handshake_complete = vdc_handshake_complete, }; static void __devinit print_version(void) { static int version_printed; if (version_printed++ == 0) printk(KERN_INFO "%s", version); } static int __devinit vdc_port_probe(struct vio_dev *vdev, const struct vio_device_id *id) { struct mdesc_handle *hp; struct vdc_port *port; int err; print_version(); hp = mdesc_grab(); err = -ENODEV; if ((vdev->dev_no << PARTITION_SHIFT) & ~(u64)MINORMASK) { printk(KERN_ERR PFX "Port id [%lu] too large.\n", vdev->dev_no); goto err_out_release_mdesc; } port = kzalloc(sizeof(*port), GFP_KERNEL); err = -ENOMEM; if (!port) { printk(KERN_ERR PFX "Cannot allocate vdc_port.\n"); goto err_out_release_mdesc; } if (vdev->dev_no >= 26) snprintf(port->disk_name, sizeof(port->disk_name), VDCBLK_NAME "%c%c", 'a' + ((int)vdev->dev_no / 26) - 1, 'a' + ((int)vdev->dev_no % 26)); else snprintf(port->disk_name, sizeof(port->disk_name), VDCBLK_NAME "%c", 'a' + ((int)vdev->dev_no % 26)); err = vio_driver_init(&port->vio, vdev, VDEV_DISK, vdc_versions, ARRAY_SIZE(vdc_versions), &vdc_vio_ops, port->disk_name); if (err) goto err_out_free_port; port->vdisk_block_size = 512; port->max_xfer_size = ((128 * 1024) / port->vdisk_block_size); port->ring_cookies = ((port->max_xfer_size * port->vdisk_block_size) / PAGE_SIZE) + 2; err = vio_ldc_alloc(&port->vio, &vdc_ldc_cfg, port); if (err) goto err_out_free_port; err = vdc_alloc_tx_ring(port); if (err) goto err_out_free_ldc; err = probe_disk(port); if (err) goto err_out_free_tx_ring; dev_set_drvdata(&vdev->dev, port); mdesc_release(hp); return 0; err_out_free_tx_ring: vdc_free_tx_ring(port); err_out_free_ldc: vio_ldc_free(&port->vio); err_out_free_port: kfree(port); err_out_release_mdesc: mdesc_release(hp); return err; } static int vdc_port_remove(struct vio_dev *vdev) { struct vdc_port *port = dev_get_drvdata(&vdev->dev); if (port) { del_timer_sync(&port->vio.timer); vdc_free_tx_ring(port); vio_ldc_free(&port->vio); dev_set_drvdata(&vdev->dev, NULL); kfree(port); } return 0; } static struct vio_device_id vdc_port_match[] = { { .type = "vdc-port", }, {}, }; MODULE_DEVICE_TABLE(vio, vdc_port_match); static struct vio_driver vdc_port_driver = { .id_table = vdc_port_match, .probe = vdc_port_probe, .remove = vdc_port_remove, .driver = { .name = "vdc_port", .owner = THIS_MODULE, } }; static int __init vdc_init(void) { int err; err = register_blkdev(0, VDCBLK_NAME); if (err < 0) goto out_err; vdc_major = err; err = vio_register_driver(&vdc_port_driver); if (err) goto out_unregister_blkdev; return 0; out_unregister_blkdev: unregister_blkdev(vdc_major, VDCBLK_NAME); vdc_major = 0; out_err: return err; } static void __exit vdc_exit(void) { vio_unregister_driver(&vdc_port_driver); unregister_blkdev(vdc_major, VDCBLK_NAME); } module_init(vdc_init); module_exit(vdc_exit);