/* * The low performance USB storage driver (ub). * * Copyright (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net) * Copyright (C) 2004 Pete Zaitcev (zaitcev@yahoo.com) * * This work is a part of Linux kernel, is derived from it, * and is not licensed separately. See file COPYING for details. * * TODO (sorted by decreasing priority) * -- Kill first_open (Al Viro fixed the block layer now) * -- Do resets with usb_device_reset (needs a thread context, use khubd) * -- set readonly flag for CDs, set removable flag for CF readers * -- do inquiry and verify we got a disk and not a tape (for LUN mismatch) * -- special case some senses, e.g. 3a/0 -> no media present, reduce retries * -- verify the 13 conditions and do bulk resets * -- kill last_pipe and simply do two-state clearing on both pipes * -- verify protocol (bulk) from USB descriptors (maybe...) * -- highmem * -- move top_sense and work_bcs into separate allocations (if they survive) * for cache purists and esoteric architectures. * -- Allocate structure for LUN 0 before the first ub_sync_tur, avoid NULL. ? * -- prune comments, they are too volumnous * -- Exterminate P3 printks * -- Resove XXX's * -- Redo "benh's retries", perhaps have spin-up code to handle them. V:D=? * -- CLEAR, CLR2STS, CLRRS seem to be ripe for refactoring. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/usb.h> #include <linux/blkdev.h> #include <linux/devfs_fs_kernel.h> #include <linux/timer.h> #include <scsi/scsi.h> #define DRV_NAME "ub" #define DEVFS_NAME DRV_NAME #define UB_MAJOR 180 /* * The command state machine is the key model for understanding of this driver. * * The general rule is that all transitions are done towards the bottom * of the diagram, thus preventing any loops. * * An exception to that is how the STAT state is handled. A counter allows it * to be re-entered along the path marked with [C]. * * +--------+ * ! INIT ! * +--------+ * ! * ub_scsi_cmd_start fails ->--------------------------------------\ * ! ! * V ! * +--------+ ! * ! CMD ! ! * +--------+ ! * ! +--------+ ! * was -EPIPE -->-------------------------------->! CLEAR ! ! * ! +--------+ ! * ! ! ! * was error -->------------------------------------- ! --------->\ * ! ! ! * /--<-- cmd->dir == NONE ? ! ! * ! ! ! ! * ! V ! ! * ! +--------+ ! ! * ! ! DATA ! ! ! * ! +--------+ ! ! * ! ! +---------+ ! ! * ! was -EPIPE -->--------------->! CLR2STS ! ! ! * ! ! +---------+ ! ! * ! ! ! ! ! * ! ! was error -->---- ! --------->\ * ! was error -->--------------------- ! ------------- ! --------->\ * ! ! ! ! ! * ! V ! ! ! * \--->+--------+ ! ! ! * ! STAT !<--------------------------/ ! ! * /--->+--------+ ! ! * ! ! ! ! * [C] was -EPIPE -->-----------\ ! ! * ! ! ! ! ! * +<---- len == 0 ! ! ! * ! ! ! ! ! * ! was error -->--------------------------------------!---------->\ * ! ! ! ! ! * +<---- bad CSW ! ! ! * +<---- bad tag ! ! ! * ! ! V ! ! * ! ! +--------+ ! ! * ! ! ! CLRRS ! ! ! * ! ! +--------+ ! ! * ! ! ! ! ! * \------- ! --------------------[C]--------\ ! ! * ! ! ! ! * cmd->error---\ +--------+ ! ! * ! +--------------->! SENSE !<----------/ ! * STAT_FAIL----/ +--------+ ! * ! ! V * ! V +--------+ * \--------------------------------\--------------------->! DONE ! * +--------+ */ /* * Definitions which have to be scattered once we understand the layout better. */ /* Transport (despite PR in the name) */ #define US_PR_BULK 0x50 /* bulk only */ /* Protocol */ #define US_SC_SCSI 0x06 /* Transparent */ /* * This many LUNs per USB device. * Every one of them takes a host, see UB_MAX_HOSTS. */ #define UB_MAX_LUNS 9 /* */ #define UB_MINORS_PER_MAJOR 8 #define UB_MAX_CDB_SIZE 16 /* Corresponds to Bulk */ #define UB_SENSE_SIZE 18 /* */ /* command block wrapper */ struct bulk_cb_wrap { __le32 Signature; /* contains 'USBC' */ u32 Tag; /* unique per command id */ __le32 DataTransferLength; /* size of data */ u8 Flags; /* direction in bit 0 */ u8 Lun; /* LUN */ u8 Length; /* of of the CDB */ u8 CDB[UB_MAX_CDB_SIZE]; /* max command */ }; #define US_BULK_CB_WRAP_LEN 31 #define US_BULK_CB_SIGN 0x43425355 /*spells out USBC */ #define US_BULK_FLAG_IN 1 #define US_BULK_FLAG_OUT 0 /* command status wrapper */ struct bulk_cs_wrap { __le32 Signature; /* should = 'USBS' */ u32 Tag; /* same as original command */ __le32 Residue; /* amount not transferred */ u8 Status; /* see below */ }; #define US_BULK_CS_WRAP_LEN 13 #define US_BULK_CS_SIGN 0x53425355 /* spells out 'USBS' */ #define US_BULK_STAT_OK 0 #define US_BULK_STAT_FAIL 1 #define US_BULK_STAT_PHASE 2 /* bulk-only class specific requests */ #define US_BULK_RESET_REQUEST 0xff #define US_BULK_GET_MAX_LUN 0xfe /* */ struct ub_dev; #define UB_MAX_REQ_SG 9 /* cdrecord requires 32KB and maybe a header */ #define UB_MAX_SECTORS 64 /* * A second is more than enough for a 32K transfer (UB_MAX_SECTORS) * even if a webcam hogs the bus, but some devices need time to spin up. */ #define UB_URB_TIMEOUT (HZ*2) #define UB_DATA_TIMEOUT (HZ*5) /* ZIP does spin-ups in the data phase */ #define UB_STAT_TIMEOUT (HZ*5) /* Same spinups and eject for a dataless cmd. */ #define UB_CTRL_TIMEOUT (HZ/2) /* 500ms ought to be enough to clear a stall */ /* * An instance of a SCSI command in transit. */ #define UB_DIR_NONE 0 #define UB_DIR_READ 1 #define UB_DIR_ILLEGAL2 2 #define UB_DIR_WRITE 3 #define UB_DIR_CHAR(c) (((c)==UB_DIR_WRITE)? 'w': \ (((c)==UB_DIR_READ)? 'r': 'n')) enum ub_scsi_cmd_state { UB_CMDST_INIT, /* Initial state */ UB_CMDST_CMD, /* Command submitted */ UB_CMDST_DATA, /* Data phase */ UB_CMDST_CLR2STS, /* Clearing before requesting status */ UB_CMDST_STAT, /* Status phase */ UB_CMDST_CLEAR, /* Clearing a stall (halt, actually) */ UB_CMDST_CLRRS, /* Clearing before retrying status */ UB_CMDST_SENSE, /* Sending Request Sense */ UB_CMDST_DONE /* Final state */ }; static char *ub_scsi_cmd_stname[] = { ". ", "Cmd", "dat", "c2s", "sts", "clr", "crs", "Sen", "fin" }; struct ub_scsi_cmd { unsigned char cdb[UB_MAX_CDB_SIZE]; unsigned char cdb_len; unsigned char dir; /* 0 - none, 1 - read, 3 - write. */ unsigned char trace_index; enum ub_scsi_cmd_state state; unsigned int tag; struct ub_scsi_cmd *next; int error; /* Return code - valid upon done */ unsigned int act_len; /* Return size */ unsigned char key, asc, ascq; /* May be valid if error==-EIO */ int stat_count; /* Retries getting status. */ unsigned int len; /* Requested length */ unsigned int current_sg; unsigned int nsg; /* sgv[nsg] */ struct scatterlist sgv[UB_MAX_REQ_SG]; struct ub_lun *lun; void (*done)(struct ub_dev *, struct ub_scsi_cmd *); void *back; }; /* */ struct ub_capacity { unsigned long nsec; /* Linux size - 512 byte sectors */ unsigned int bsize; /* Linux hardsect_size */ unsigned int bshift; /* Shift between 512 and hard sects */ }; /* * The SCSI command tracing structure. */ #define SCMD_ST_HIST_SZ 8 #define SCMD_TRACE_SZ 63 /* Less than 4KB of 61-byte lines */ struct ub_scsi_cmd_trace { int hcur; unsigned int tag; unsigned int req_size, act_size; unsigned char op; unsigned char dir; unsigned char key, asc, ascq; char st_hst[SCMD_ST_HIST_SZ]; }; struct ub_scsi_trace { int cur; struct ub_scsi_cmd_trace vec[SCMD_TRACE_SZ]; }; /* * This is a direct take-off from linux/include/completion.h * The difference is that I do not wait on this thing, just poll. * When I want to wait (ub_probe), I just use the stock completion. * * Note that INIT_COMPLETION takes no lock. It is correct. But why * in the bloody hell that thing takes struct instead of pointer to struct * is quite beyond me. I just copied it from the stock completion. */ struct ub_completion { unsigned int done; spinlock_t lock; }; static inline void ub_init_completion(struct ub_completion *x) { x->done = 0; spin_lock_init(&x->lock); } #define UB_INIT_COMPLETION(x) ((x).done = 0) static void ub_complete(struct ub_completion *x) { unsigned long flags; spin_lock_irqsave(&x->lock, flags); x->done++; spin_unlock_irqrestore(&x->lock, flags); } static int ub_is_completed(struct ub_completion *x) { unsigned long flags; int ret; spin_lock_irqsave(&x->lock, flags); ret = x->done; spin_unlock_irqrestore(&x->lock, flags); return ret; } /* */ struct ub_scsi_cmd_queue { int qlen, qmax; struct ub_scsi_cmd *head, *tail; }; /* * The block device instance (one per LUN). */ struct ub_lun { struct ub_dev *udev; struct list_head link; struct gendisk *disk; int id; /* Host index */ int num; /* LUN number */ char name[16]; int changed; /* Media was changed */ int removable; int readonly; int first_open; /* Kludge. See ub_bd_open. */ /* Use Ingo's mempool if or when we have more than one command. */ /* * Currently we never need more than one command for the whole device. * However, giving every LUN a command is a cheap and automatic way * to enforce fairness between them. */ int cmda[1]; struct ub_scsi_cmd cmdv[1]; struct ub_capacity capacity; }; /* * The USB device instance. */ struct ub_dev { spinlock_t lock; atomic_t poison; /* The USB device is disconnected */ int openc; /* protected by ub_lock! */ /* kref is too implicit for our taste */ unsigned int tagcnt; char name[12]; struct usb_device *dev; struct usb_interface *intf; struct list_head luns; unsigned int send_bulk_pipe; /* cached pipe values */ unsigned int recv_bulk_pipe; unsigned int send_ctrl_pipe; unsigned int recv_ctrl_pipe; struct tasklet_struct tasklet; struct ub_scsi_cmd_queue cmd_queue; struct ub_scsi_cmd top_rqs_cmd; /* REQUEST SENSE */ unsigned char top_sense[UB_SENSE_SIZE]; struct ub_completion work_done; struct urb work_urb; struct timer_list work_timer; int last_pipe; /* What might need clearing */ __le32 signature; /* Learned signature */ struct bulk_cb_wrap work_bcb; struct bulk_cs_wrap work_bcs; struct usb_ctrlrequest work_cr; int sg_stat[6]; struct ub_scsi_trace tr; }; /* */ static void ub_cleanup(struct ub_dev *sc); static int ub_request_fn_1(struct ub_lun *lun, struct request *rq); static int ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun, struct ub_scsi_cmd *cmd, struct request *rq); static int ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun, struct ub_scsi_cmd *cmd, struct request *rq); static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd); static void ub_end_rq(struct request *rq, int uptodate); static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd); static void ub_urb_complete(struct urb *urb, struct pt_regs *pt); static void ub_scsi_action(unsigned long _dev); static void ub_scsi_dispatch(struct ub_dev *sc); static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd); static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd); static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc); static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd); static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd); static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd); static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd); static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int stalled_pipe); static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd); static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun); static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun, struct ub_capacity *ret); static int ub_probe_lun(struct ub_dev *sc, int lnum); /* */ static struct usb_device_id ub_usb_ids[] = { // { USB_DEVICE_VER(0x0781, 0x0002, 0x0009, 0x0009) }, /* SDDR-31 */ { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, US_SC_SCSI, US_PR_BULK) }, { } }; MODULE_DEVICE_TABLE(usb, ub_usb_ids); /* * Find me a way to identify "next free minor" for add_disk(), * and the array disappears the next day. However, the number of * hosts has something to do with the naming and /proc/partitions. * This has to be thought out in detail before changing. * If UB_MAX_HOST was 1000, we'd use a bitmap. Or a better data structure. */ #define UB_MAX_HOSTS 26 static char ub_hostv[UB_MAX_HOSTS]; static DEFINE_SPINLOCK(ub_lock); /* Locks globals and ->openc */ /* * The SCSI command tracing procedures. */ static void ub_cmdtr_new(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { int n; struct ub_scsi_cmd_trace *t; if ((n = sc->tr.cur + 1) == SCMD_TRACE_SZ) n = 0; t = &sc->tr.vec[n]; memset(t, 0, sizeof(struct ub_scsi_cmd_trace)); t->tag = cmd->tag; t->op = cmd->cdb[0]; t->dir = cmd->dir; t->req_size = cmd->len; t->st_hst[0] = cmd->state; sc->tr.cur = n; cmd->trace_index = n; } static void ub_cmdtr_state(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { int n; struct ub_scsi_cmd_trace *t; t = &sc->tr.vec[cmd->trace_index]; if (t->tag == cmd->tag) { if ((n = t->hcur + 1) == SCMD_ST_HIST_SZ) n = 0; t->st_hst[n] = cmd->state; t->hcur = n; } } static void ub_cmdtr_act_len(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { struct ub_scsi_cmd_trace *t; t = &sc->tr.vec[cmd->trace_index]; if (t->tag == cmd->tag) t->act_size = cmd->act_len; } static void ub_cmdtr_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd, unsigned char *sense) { struct ub_scsi_cmd_trace *t; t = &sc->tr.vec[cmd->trace_index]; if (t->tag == cmd->tag) { t->key = sense[2] & 0x0F; t->asc = sense[12]; t->ascq = sense[13]; } } static ssize_t ub_diag_show(struct device *dev, struct device_attribute *attr, char *page) { struct usb_interface *intf; struct ub_dev *sc; struct list_head *p; struct ub_lun *lun; int cnt; unsigned long flags; int nc, nh; int i, j; struct ub_scsi_cmd_trace *t; intf = to_usb_interface(dev); sc = usb_get_intfdata(intf); if (sc == NULL) return 0; cnt = 0; spin_lock_irqsave(&sc->lock, flags); cnt += sprintf(page + cnt, "qlen %d qmax %d\n", sc->cmd_queue.qlen, sc->cmd_queue.qmax); cnt += sprintf(page + cnt, "sg %d %d %d %d %d .. %d\n", sc->sg_stat[0], sc->sg_stat[1], sc->sg_stat[2], sc->sg_stat[3], sc->sg_stat[4], sc->sg_stat[5]); list_for_each (p, &sc->luns) { lun = list_entry(p, struct ub_lun, link); cnt += sprintf(page + cnt, "lun %u changed %d removable %d readonly %d\n", lun->num, lun->changed, lun->removable, lun->readonly); } if ((nc = sc->tr.cur + 1) == SCMD_TRACE_SZ) nc = 0; for (j = 0; j < SCMD_TRACE_SZ; j++) { t = &sc->tr.vec[nc]; cnt += sprintf(page + cnt, "%08x %02x", t->tag, t->op); if (t->op == REQUEST_SENSE) { cnt += sprintf(page + cnt, " [sense %x %02x %02x]", t->key, t->asc, t->ascq); } else { cnt += sprintf(page + cnt, " %c", UB_DIR_CHAR(t->dir)); cnt += sprintf(page + cnt, " [%5d %5d]", t->req_size, t->act_size); } if ((nh = t->hcur + 1) == SCMD_ST_HIST_SZ) nh = 0; for (i = 0; i < SCMD_ST_HIST_SZ; i++) { cnt += sprintf(page + cnt, " %s", ub_scsi_cmd_stname[(int)t->st_hst[nh]]); if (++nh == SCMD_ST_HIST_SZ) nh = 0; } cnt += sprintf(page + cnt, "\n"); if (++nc == SCMD_TRACE_SZ) nc = 0; } spin_unlock_irqrestore(&sc->lock, flags); return cnt; } static DEVICE_ATTR(diag, S_IRUGO, ub_diag_show, NULL); /* N.B. World readable */ /* * The id allocator. * * This also stores the host for indexing by minor, which is somewhat dirty. */ static int ub_id_get(void) { unsigned long flags; int i; spin_lock_irqsave(&ub_lock, flags); for (i = 0; i < UB_MAX_HOSTS; i++) { if (ub_hostv[i] == 0) { ub_hostv[i] = 1; spin_unlock_irqrestore(&ub_lock, flags); return i; } } spin_unlock_irqrestore(&ub_lock, flags); return -1; } static void ub_id_put(int id) { unsigned long flags; if (id < 0 || id >= UB_MAX_HOSTS) { printk(KERN_ERR DRV_NAME ": bad host ID %d\n", id); return; } spin_lock_irqsave(&ub_lock, flags); if (ub_hostv[id] == 0) { spin_unlock_irqrestore(&ub_lock, flags); printk(KERN_ERR DRV_NAME ": freeing free host ID %d\n", id); return; } ub_hostv[id] = 0; spin_unlock_irqrestore(&ub_lock, flags); } /* * Downcount for deallocation. This rides on two assumptions: * - once something is poisoned, its refcount cannot grow * - opens cannot happen at this time (del_gendisk was done) * If the above is true, we can drop the lock, which we need for * blk_cleanup_queue(): the silly thing may attempt to sleep. * [Actually, it never needs to sleep for us, but it calls might_sleep()] */ static void ub_put(struct ub_dev *sc) { unsigned long flags; spin_lock_irqsave(&ub_lock, flags); --sc->openc; if (sc->openc == 0 && atomic_read(&sc->poison)) { spin_unlock_irqrestore(&ub_lock, flags); ub_cleanup(sc); } else { spin_unlock_irqrestore(&ub_lock, flags); } } /* * Final cleanup and deallocation. */ static void ub_cleanup(struct ub_dev *sc) { struct list_head *p; struct ub_lun *lun; request_queue_t *q; while (!list_empty(&sc->luns)) { p = sc->luns.next; lun = list_entry(p, struct ub_lun, link); list_del(p); /* I don't think queue can be NULL. But... Stolen from sx8.c */ if ((q = lun->disk->queue) != NULL) blk_cleanup_queue(q); /* * If we zero disk->private_data BEFORE put_disk, we have * to check for NULL all over the place in open, release, * check_media and revalidate, because the block level * semaphore is well inside the put_disk. * But we cannot zero after the call, because *disk is gone. * The sd.c is blatantly racy in this area. */ /* disk->private_data = NULL; */ put_disk(lun->disk); lun->disk = NULL; ub_id_put(lun->id); kfree(lun); } kfree(sc); } /* * The "command allocator". */ static struct ub_scsi_cmd *ub_get_cmd(struct ub_lun *lun) { struct ub_scsi_cmd *ret; if (lun->cmda[0]) return NULL; ret = &lun->cmdv[0]; lun->cmda[0] = 1; return ret; } static void ub_put_cmd(struct ub_lun *lun, struct ub_scsi_cmd *cmd) { if (cmd != &lun->cmdv[0]) { printk(KERN_WARNING "%s: releasing a foreign cmd %p\n", lun->name, cmd); return; } if (!lun->cmda[0]) { printk(KERN_WARNING "%s: releasing a free cmd\n", lun->name); return; } lun->cmda[0] = 0; } /* * The command queue. */ static void ub_cmdq_add(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { struct ub_scsi_cmd_queue *t = &sc->cmd_queue; if (t->qlen++ == 0) { t->head = cmd; t->tail = cmd; } else { t->tail->next = cmd; t->tail = cmd; } if (t->qlen > t->qmax) t->qmax = t->qlen; } static void ub_cmdq_insert(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { struct ub_scsi_cmd_queue *t = &sc->cmd_queue; if (t->qlen++ == 0) { t->head = cmd; t->tail = cmd; } else { cmd->next = t->head; t->head = cmd; } if (t->qlen > t->qmax) t->qmax = t->qlen; } static struct ub_scsi_cmd *ub_cmdq_pop(struct ub_dev *sc) { struct ub_scsi_cmd_queue *t = &sc->cmd_queue; struct ub_scsi_cmd *cmd; if (t->qlen == 0) return NULL; if (--t->qlen == 0) t->tail = NULL; cmd = t->head; t->head = cmd->next; cmd->next = NULL; return cmd; } #define ub_cmdq_peek(sc) ((sc)->cmd_queue.head) /* * The request function is our main entry point */ static void ub_request_fn(request_queue_t *q) { struct ub_lun *lun = q->queuedata; struct request *rq; while ((rq = elv_next_request(q)) != NULL) { if (ub_request_fn_1(lun, rq) != 0) { blk_stop_queue(q); break; } } } static int ub_request_fn_1(struct ub_lun *lun, struct request *rq) { struct ub_dev *sc = lun->udev; struct ub_scsi_cmd *cmd; int rc; if (atomic_read(&sc->poison) || lun->changed) { blkdev_dequeue_request(rq); ub_end_rq(rq, 0); return 0; } if ((cmd = ub_get_cmd(lun)) == NULL) return -1; memset(cmd, 0, sizeof(struct ub_scsi_cmd)); blkdev_dequeue_request(rq); if (blk_pc_request(rq)) { rc = ub_cmd_build_packet(sc, lun, cmd, rq); } else { rc = ub_cmd_build_block(sc, lun, cmd, rq); } if (rc != 0) { ub_put_cmd(lun, cmd); ub_end_rq(rq, 0); return 0; } cmd->state = UB_CMDST_INIT; cmd->lun = lun; cmd->done = ub_rw_cmd_done; cmd->back = rq; cmd->tag = sc->tagcnt++; if (ub_submit_scsi(sc, cmd) != 0) { ub_put_cmd(lun, cmd); ub_end_rq(rq, 0); return 0; } return 0; } static int ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun, struct ub_scsi_cmd *cmd, struct request *rq) { int ub_dir; int n_elem; unsigned int block, nblks; if (rq_data_dir(rq) == WRITE) ub_dir = UB_DIR_WRITE; else ub_dir = UB_DIR_READ; cmd->dir = ub_dir; /* * get scatterlist from block layer */ n_elem = blk_rq_map_sg(lun->disk->queue, rq, &cmd->sgv[0]); if (n_elem <= 0) { printk(KERN_INFO "%s: failed request map (%d)\n", sc->name, n_elem); /* P3 */ return -1; /* request with no s/g entries? */ } if (n_elem > UB_MAX_REQ_SG) { /* Paranoia */ printk(KERN_WARNING "%s: request with %d segments\n", sc->name, n_elem); return -1; } cmd->nsg = n_elem; sc->sg_stat[n_elem < 5 ? n_elem : 5]++; /* * build the command * * The call to blk_queue_hardsect_size() guarantees that request * is aligned, but it is given in terms of 512 byte units, always. */ block = rq->sector >> lun->capacity.bshift; nblks = rq->nr_sectors >> lun->capacity.bshift; cmd->cdb[0] = (ub_dir == UB_DIR_READ)? READ_10: WRITE_10; /* 10-byte uses 4 bytes of LBA: 2147483648KB, 2097152MB, 2048GB */ cmd->cdb[2] = block >> 24; cmd->cdb[3] = block >> 16; cmd->cdb[4] = block >> 8; cmd->cdb[5] = block; cmd->cdb[7] = nblks >> 8; cmd->cdb[8] = nblks; cmd->cdb_len = 10; cmd->len = rq->nr_sectors * 512; return 0; } static int ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun, struct ub_scsi_cmd *cmd, struct request *rq) { int n_elem; if (rq->data_len == 0) { cmd->dir = UB_DIR_NONE; } else { if (rq_data_dir(rq) == WRITE) cmd->dir = UB_DIR_WRITE; else cmd->dir = UB_DIR_READ; } /* * get scatterlist from block layer */ n_elem = blk_rq_map_sg(lun->disk->queue, rq, &cmd->sgv[0]); if (n_elem < 0) { printk(KERN_INFO "%s: failed request map (%d)\n", sc->name, n_elem); /* P3 */ return -1; } if (n_elem > UB_MAX_REQ_SG) { /* Paranoia */ printk(KERN_WARNING "%s: request with %d segments\n", sc->name, n_elem); return -1; } cmd->nsg = n_elem; sc->sg_stat[n_elem < 5 ? n_elem : 5]++; memcpy(&cmd->cdb, rq->cmd, rq->cmd_len); cmd->cdb_len = rq->cmd_len; cmd->len = rq->data_len; return 0; } static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { struct request *rq = cmd->back; struct ub_lun *lun = cmd->lun; int uptodate; if (cmd->error == 0) { uptodate = 1; if (blk_pc_request(rq)) { if (cmd->act_len >= rq->data_len) rq->data_len = 0; else rq->data_len -= cmd->act_len; } } else { uptodate = 0; if (blk_pc_request(rq)) { /* UB_SENSE_SIZE is smaller than SCSI_SENSE_BUFFERSIZE */ memcpy(rq->sense, sc->top_sense, UB_SENSE_SIZE); rq->sense_len = UB_SENSE_SIZE; if (sc->top_sense[0] != 0) rq->errors = SAM_STAT_CHECK_CONDITION; else rq->errors = DID_ERROR << 16; } } ub_put_cmd(lun, cmd); ub_end_rq(rq, uptodate); blk_start_queue(lun->disk->queue); } static void ub_end_rq(struct request *rq, int uptodate) { int rc; rc = end_that_request_first(rq, uptodate, rq->hard_nr_sectors); // assert(rc == 0); end_that_request_last(rq); } /* * Submit a regular SCSI operation (not an auto-sense). * * The Iron Law of Good Submit Routine is: * Zero return - callback is done, Nonzero return - callback is not done. * No exceptions. * * Host is assumed locked. * * XXX We only support Bulk for the moment. */ static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { if (cmd->state != UB_CMDST_INIT || (cmd->dir != UB_DIR_NONE && cmd->len == 0)) { return -EINVAL; } ub_cmdq_add(sc, cmd); /* * We can call ub_scsi_dispatch(sc) right away here, but it's a little * safer to jump to a tasklet, in case upper layers do something silly. */ tasklet_schedule(&sc->tasklet); return 0; } /* * Submit the first URB for the queued command. * This function does not deal with queueing in any way. */ static int ub_scsi_cmd_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { struct bulk_cb_wrap *bcb; int rc; bcb = &sc->work_bcb; /* * ``If the allocation length is eighteen or greater, and a device * server returns less than eithteen bytes of data, the application * client should assume that the bytes not transferred would have been * zeroes had the device server returned those bytes.'' * * We zero sense for all commands so that when a packet request * fails it does not return a stale sense. */ memset(&sc->top_sense, 0, UB_SENSE_SIZE); /* set up the command wrapper */ bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN); bcb->Tag = cmd->tag; /* Endianness is not important */ bcb->DataTransferLength = cpu_to_le32(cmd->len); bcb->Flags = (cmd->dir == UB_DIR_READ) ? 0x80 : 0; bcb->Lun = (cmd->lun != NULL) ? cmd->lun->num : 0; bcb->Length = cmd->cdb_len; /* copy the command payload */ memcpy(bcb->CDB, cmd->cdb, UB_MAX_CDB_SIZE); UB_INIT_COMPLETION(sc->work_done); sc->last_pipe = sc->send_bulk_pipe; usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->send_bulk_pipe, bcb, US_BULK_CB_WRAP_LEN, ub_urb_complete, sc); /* Fill what we shouldn't be filling, because usb-storage did so. */ sc->work_urb.actual_length = 0; sc->work_urb.error_count = 0; sc->work_urb.status = 0; if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) { /* XXX Clear stalls */ ub_complete(&sc->work_done); return rc; } sc->work_timer.expires = jiffies + UB_URB_TIMEOUT; add_timer(&sc->work_timer); cmd->state = UB_CMDST_CMD; ub_cmdtr_state(sc, cmd); return 0; } /* * Timeout handler. */ static void ub_urb_timeout(unsigned long arg) { struct ub_dev *sc = (struct ub_dev *) arg; unsigned long flags; spin_lock_irqsave(&sc->lock, flags); usb_unlink_urb(&sc->work_urb); spin_unlock_irqrestore(&sc->lock, flags); } /* * Completion routine for the work URB. * * This can be called directly from usb_submit_urb (while we have * the sc->lock taken) and from an interrupt (while we do NOT have * the sc->lock taken). Therefore, bounce this off to a tasklet. */ static void ub_urb_complete(struct urb *urb, struct pt_regs *pt) { struct ub_dev *sc = urb->context; ub_complete(&sc->work_done); tasklet_schedule(&sc->tasklet); } static void ub_scsi_action(unsigned long _dev) { struct ub_dev *sc = (struct ub_dev *) _dev; unsigned long flags; spin_lock_irqsave(&sc->lock, flags); del_timer(&sc->work_timer); ub_scsi_dispatch(sc); spin_unlock_irqrestore(&sc->lock, flags); } static void ub_scsi_dispatch(struct ub_dev *sc) { struct ub_scsi_cmd *cmd; int rc; while ((cmd = ub_cmdq_peek(sc)) != NULL) { if (cmd->state == UB_CMDST_DONE) { ub_cmdq_pop(sc); (*cmd->done)(sc, cmd); } else if (cmd->state == UB_CMDST_INIT) { ub_cmdtr_new(sc, cmd); if ((rc = ub_scsi_cmd_start(sc, cmd)) == 0) break; cmd->error = rc; cmd->state = UB_CMDST_DONE; ub_cmdtr_state(sc, cmd); } else { if (!ub_is_completed(&sc->work_done)) break; ub_scsi_urb_compl(sc, cmd); } } } static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { struct urb *urb = &sc->work_urb; struct bulk_cs_wrap *bcs; int rc; if (atomic_read(&sc->poison)) { /* A little too simplistic, I feel... */ goto Bad_End; } if (cmd->state == UB_CMDST_CLEAR) { if (urb->status == -EPIPE) { /* * STALL while clearning STALL. * The control pipe clears itself - nothing to do. * XXX Might try to reset the device here and retry. */ printk(KERN_NOTICE "%s: stall on control pipe\n", sc->name); goto Bad_End; } /* * We ignore the result for the halt clear. */ /* reset the endpoint toggle */ usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe), usb_pipeout(sc->last_pipe), 0); ub_state_sense(sc, cmd); } else if (cmd->state == UB_CMDST_CLR2STS) { if (urb->status == -EPIPE) { /* * STALL while clearning STALL. * The control pipe clears itself - nothing to do. * XXX Might try to reset the device here and retry. */ printk(KERN_NOTICE "%s: stall on control pipe\n", sc->name); goto Bad_End; } /* * We ignore the result for the halt clear. */ /* reset the endpoint toggle */ usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe), usb_pipeout(sc->last_pipe), 0); ub_state_stat(sc, cmd); } else if (cmd->state == UB_CMDST_CLRRS) { if (urb->status == -EPIPE) { /* * STALL while clearning STALL. * The control pipe clears itself - nothing to do. * XXX Might try to reset the device here and retry. */ printk(KERN_NOTICE "%s: stall on control pipe\n", sc->name); goto Bad_End; } /* * We ignore the result for the halt clear. */ /* reset the endpoint toggle */ usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe), usb_pipeout(sc->last_pipe), 0); ub_state_stat_counted(sc, cmd); } else if (cmd->state == UB_CMDST_CMD) { if (urb->status == -EPIPE) { rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe); if (rc != 0) { printk(KERN_NOTICE "%s: " "unable to submit clear (%d)\n", sc->name, rc); /* * This is typically ENOMEM or some other such shit. * Retrying is pointless. Just do Bad End on it... */ goto Bad_End; } cmd->state = UB_CMDST_CLEAR; ub_cmdtr_state(sc, cmd); return; } if (urb->status != 0) { goto Bad_End; } if (urb->actual_length != US_BULK_CB_WRAP_LEN) { /* XXX Must do reset here to unconfuse the device */ goto Bad_End; } if (cmd->dir == UB_DIR_NONE || cmd->nsg < 1) { ub_state_stat(sc, cmd); return; } // udelay(125); // usb-storage has this ub_data_start(sc, cmd); } else if (cmd->state == UB_CMDST_DATA) { if (urb->status == -EPIPE) { rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe); if (rc != 0) { printk(KERN_NOTICE "%s: " "unable to submit clear (%d)\n", sc->name, rc); /* * This is typically ENOMEM or some other such shit. * Retrying is pointless. Just do Bad End on it... */ goto Bad_End; } cmd->state = UB_CMDST_CLR2STS; ub_cmdtr_state(sc, cmd); return; } if (urb->status == -EOVERFLOW) { /* * A babble? Failure, but we must transfer CSW now. * XXX This is going to end in perpetual babble. Reset. */ cmd->error = -EOVERFLOW; /* A cheap trick... */ ub_state_stat(sc, cmd); return; } if (urb->status != 0) goto Bad_End; cmd->act_len += urb->actual_length; ub_cmdtr_act_len(sc, cmd); if (++cmd->current_sg < cmd->nsg) { ub_data_start(sc, cmd); return; } ub_state_stat(sc, cmd); } else if (cmd->state == UB_CMDST_STAT) { if (urb->status == -EPIPE) { rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe); if (rc != 0) { printk(KERN_NOTICE "%s: " "unable to submit clear (%d)\n", sc->name, rc); /* * This is typically ENOMEM or some other such shit. * Retrying is pointless. Just do Bad End on it... */ goto Bad_End; } /* * Having a stall when getting CSW is an error, so * make sure uppper levels are not oblivious to it. */ cmd->error = -EIO; /* A cheap trick... */ cmd->state = UB_CMDST_CLRRS; ub_cmdtr_state(sc, cmd); return; } if (urb->status == -EOVERFLOW) { /* * XXX We are screwed here. Retrying is pointless, * because the pipelined data will not get in until * we read with a big enough buffer. We must reset XXX. */ goto Bad_End; } if (urb->status != 0) goto Bad_End; if (urb->actual_length == 0) { ub_state_stat_counted(sc, cmd); return; } /* * Check the returned Bulk protocol status. * The status block has to be validated first. */ bcs = &sc->work_bcs; if (sc->signature == cpu_to_le32(0)) { /* * This is the first reply, so do not perform the check. * Instead, remember the signature the device uses * for future checks. But do not allow a nul. */ sc->signature = bcs->Signature; if (sc->signature == cpu_to_le32(0)) { ub_state_stat_counted(sc, cmd); return; } } else { if (bcs->Signature != sc->signature) { ub_state_stat_counted(sc, cmd); return; } } if (bcs->Tag != cmd->tag) { /* * This usually happens when we disagree with the * device's microcode about something. For instance, * a few of them throw this after timeouts. They buffer * commands and reply at commands we timed out before. * Without flushing these replies we loop forever. */ ub_state_stat_counted(sc, cmd); return; } rc = le32_to_cpu(bcs->Residue); if (rc != cmd->len - cmd->act_len) { /* * It is all right to transfer less, the caller has * to check. But it's not all right if the device * counts disagree with our counts. */ /* P3 */ printk("%s: resid %d len %d act %d\n", sc->name, rc, cmd->len, cmd->act_len); goto Bad_End; } switch (bcs->Status) { case US_BULK_STAT_OK: break; case US_BULK_STAT_FAIL: ub_state_sense(sc, cmd); return; case US_BULK_STAT_PHASE: /* XXX We must reset the transport here */ /* P3 */ printk("%s: status PHASE\n", sc->name); goto Bad_End; default: printk(KERN_INFO "%s: unknown CSW status 0x%x\n", sc->name, bcs->Status); goto Bad_End; } /* Not zeroing error to preserve a babble indicator */ if (cmd->error != 0) { ub_state_sense(sc, cmd); return; } cmd->state = UB_CMDST_DONE; ub_cmdtr_state(sc, cmd); ub_cmdq_pop(sc); (*cmd->done)(sc, cmd); } else if (cmd->state == UB_CMDST_SENSE) { ub_state_done(sc, cmd, -EIO); } else { printk(KERN_WARNING "%s: " "wrong command state %d\n", sc->name, cmd->state); goto Bad_End; } return; Bad_End: /* Little Excel is dead */ ub_state_done(sc, cmd, -EIO); } /* * Factorization helper for the command state machine: * Initiate a data segment transfer. */ static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { struct scatterlist *sg = &cmd->sgv[cmd->current_sg]; int pipe; int rc; UB_INIT_COMPLETION(sc->work_done); if (cmd->dir == UB_DIR_READ) pipe = sc->recv_bulk_pipe; else pipe = sc->send_bulk_pipe; sc->last_pipe = pipe; usb_fill_bulk_urb(&sc->work_urb, sc->dev, pipe, page_address(sg->page) + sg->offset, sg->length, ub_urb_complete, sc); sc->work_urb.actual_length = 0; sc->work_urb.error_count = 0; sc->work_urb.status = 0; if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) { /* XXX Clear stalls */ ub_complete(&sc->work_done); ub_state_done(sc, cmd, rc); return; } sc->work_timer.expires = jiffies + UB_DATA_TIMEOUT; add_timer(&sc->work_timer); cmd->state = UB_CMDST_DATA; ub_cmdtr_state(sc, cmd); } /* * Factorization helper for the command state machine: * Finish the command. */ static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc) { cmd->error = rc; cmd->state = UB_CMDST_DONE; ub_cmdtr_state(sc, cmd); ub_cmdq_pop(sc); (*cmd->done)(sc, cmd); } /* * Factorization helper for the command state machine: * Submit a CSW read. */ static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { int rc; UB_INIT_COMPLETION(sc->work_done); sc->last_pipe = sc->recv_bulk_pipe; usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->recv_bulk_pipe, &sc->work_bcs, US_BULK_CS_WRAP_LEN, ub_urb_complete, sc); sc->work_urb.actual_length = 0; sc->work_urb.error_count = 0; sc->work_urb.status = 0; if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) { /* XXX Clear stalls */ ub_complete(&sc->work_done); ub_state_done(sc, cmd, rc); return -1; } sc->work_timer.expires = jiffies + UB_STAT_TIMEOUT; add_timer(&sc->work_timer); return 0; } /* * Factorization helper for the command state machine: * Submit a CSW read and go to STAT state. */ static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { if (__ub_state_stat(sc, cmd) != 0) return; cmd->stat_count = 0; cmd->state = UB_CMDST_STAT; ub_cmdtr_state(sc, cmd); } /* * Factorization helper for the command state machine: * Submit a CSW read and go to STAT state with counter (along [C] path). */ static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { if (++cmd->stat_count >= 4) { ub_state_sense(sc, cmd); return; } if (__ub_state_stat(sc, cmd) != 0) return; cmd->state = UB_CMDST_STAT; ub_cmdtr_state(sc, cmd); } /* * Factorization helper for the command state machine: * Submit a REQUEST SENSE and go to SENSE state. */ static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { struct ub_scsi_cmd *scmd; struct scatterlist *sg; int rc; if (cmd->cdb[0] == REQUEST_SENSE) { rc = -EPIPE; goto error; } scmd = &sc->top_rqs_cmd; memset(scmd, 0, sizeof(struct ub_scsi_cmd)); scmd->cdb[0] = REQUEST_SENSE; scmd->cdb[4] = UB_SENSE_SIZE; scmd->cdb_len = 6; scmd->dir = UB_DIR_READ; scmd->state = UB_CMDST_INIT; scmd->nsg = 1; sg = &scmd->sgv[0]; sg->page = virt_to_page(sc->top_sense); sg->offset = (unsigned long)sc->top_sense & (PAGE_SIZE-1); sg->length = UB_SENSE_SIZE; scmd->len = UB_SENSE_SIZE; scmd->lun = cmd->lun; scmd->done = ub_top_sense_done; scmd->back = cmd; scmd->tag = sc->tagcnt++; cmd->state = UB_CMDST_SENSE; ub_cmdtr_state(sc, cmd); ub_cmdq_insert(sc, scmd); return; error: ub_state_done(sc, cmd, rc); } /* * A helper for the command's state machine: * Submit a stall clear. */ static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int stalled_pipe) { int endp; struct usb_ctrlrequest *cr; int rc; endp = usb_pipeendpoint(stalled_pipe); if (usb_pipein (stalled_pipe)) endp |= USB_DIR_IN; cr = &sc->work_cr; cr->bRequestType = USB_RECIP_ENDPOINT; cr->bRequest = USB_REQ_CLEAR_FEATURE; cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT); cr->wIndex = cpu_to_le16(endp); cr->wLength = cpu_to_le16(0); UB_INIT_COMPLETION(sc->work_done); usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe, (unsigned char*) cr, NULL, 0, ub_urb_complete, sc); sc->work_urb.actual_length = 0; sc->work_urb.error_count = 0; sc->work_urb.status = 0; if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) { ub_complete(&sc->work_done); return rc; } sc->work_timer.expires = jiffies + UB_CTRL_TIMEOUT; add_timer(&sc->work_timer); return 0; } /* */ static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd) { unsigned char *sense = sc->top_sense; struct ub_scsi_cmd *cmd; /* * Ignoring scmd->act_len, because the buffer was pre-zeroed. */ ub_cmdtr_sense(sc, scmd, sense); /* * Find the command which triggered the unit attention or a check, * save the sense into it, and advance its state machine. */ if ((cmd = ub_cmdq_peek(sc)) == NULL) { printk(KERN_WARNING "%s: sense done while idle\n", sc->name); return; } if (cmd != scmd->back) { printk(KERN_WARNING "%s: " "sense done for wrong command 0x%x\n", sc->name, cmd->tag); return; } if (cmd->state != UB_CMDST_SENSE) { printk(KERN_WARNING "%s: " "sense done with bad cmd state %d\n", sc->name, cmd->state); return; } cmd->key = sense[2] & 0x0F; cmd->asc = sense[12]; cmd->ascq = sense[13]; ub_scsi_urb_compl(sc, cmd); } /* * This is called from a process context. */ static void ub_revalidate(struct ub_dev *sc, struct ub_lun *lun) { lun->readonly = 0; /* XXX Query this from the device */ lun->capacity.nsec = 0; lun->capacity.bsize = 512; lun->capacity.bshift = 0; if (ub_sync_tur(sc, lun) != 0) return; /* Not ready */ lun->changed = 0; if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) { /* * The retry here means something is wrong, either with the * device, with the transport, or with our code. * We keep this because sd.c has retries for capacity. */ if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) { lun->capacity.nsec = 0; lun->capacity.bsize = 512; lun->capacity.bshift = 0; } } } /* * The open funcion. * This is mostly needed to keep refcounting, but also to support * media checks on removable media drives. */ static int ub_bd_open(struct inode *inode, struct file *filp) { struct gendisk *disk = inode->i_bdev->bd_disk; struct ub_lun *lun; struct ub_dev *sc; unsigned long flags; int rc; if ((lun = disk->private_data) == NULL) return -ENXIO; sc = lun->udev; spin_lock_irqsave(&ub_lock, flags); if (atomic_read(&sc->poison)) { spin_unlock_irqrestore(&ub_lock, flags); return -ENXIO; } sc->openc++; spin_unlock_irqrestore(&ub_lock, flags); /* * This is a workaround for a specific problem in our block layer. * In 2.6.9, register_disk duplicates the code from rescan_partitions. * However, if we do add_disk with a device which persistently reports * a changed media, add_disk calls register_disk, which does do_open, * which will call rescan_paritions for changed media. After that, * register_disk attempts to do it all again and causes double kobject * registration and a eventually an oops on module removal. * * The bottom line is, Al Viro says that we should not allow * bdev->bd_invalidated to be set when doing add_disk no matter what. */ if (lun->first_open) { lun->first_open = 0; if (lun->changed) { rc = -ENOMEDIUM; goto err_open; } } if (lun->removable || lun->readonly) check_disk_change(inode->i_bdev); /* * The sd.c considers ->media_present and ->changed not equivalent, * under some pretty murky conditions (a failure of READ CAPACITY). * We may need it one day. */ if (lun->removable && lun->changed && !(filp->f_flags & O_NDELAY)) { rc = -ENOMEDIUM; goto err_open; } if (lun->readonly && (filp->f_mode & FMODE_WRITE)) { rc = -EROFS; goto err_open; } return 0; err_open: ub_put(sc); return rc; } /* */ static int ub_bd_release(struct inode *inode, struct file *filp) { struct gendisk *disk = inode->i_bdev->bd_disk; struct ub_lun *lun = disk->private_data; struct ub_dev *sc = lun->udev; ub_put(sc); return 0; } /* * The ioctl interface. */ static int ub_bd_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { struct gendisk *disk = inode->i_bdev->bd_disk; void __user *usermem = (void __user *) arg; return scsi_cmd_ioctl(filp, disk, cmd, usermem); } /* * This is called once a new disk was seen by the block layer or by ub_probe(). * The main onjective here is to discover the features of the media such as * the capacity, read-only status, etc. USB storage generally does not * need to be spun up, but if we needed it, this would be the place. * * This call can sleep. * * The return code is not used. */ static int ub_bd_revalidate(struct gendisk *disk) { struct ub_lun *lun = disk->private_data; ub_revalidate(lun->udev, lun); /* XXX Support sector size switching like in sr.c */ blk_queue_hardsect_size(disk->queue, lun->capacity.bsize); set_capacity(disk, lun->capacity.nsec); // set_disk_ro(sdkp->disk, lun->readonly); return 0; } /* * The check is called by the block layer to verify if the media * is still available. It is supposed to be harmless, lightweight and * non-intrusive in case the media was not changed. * * This call can sleep. * * The return code is bool! */ static int ub_bd_media_changed(struct gendisk *disk) { struct ub_lun *lun = disk->private_data; if (!lun->removable) return 0; /* * We clean checks always after every command, so this is not * as dangerous as it looks. If the TEST_UNIT_READY fails here, * the device is actually not ready with operator or software * intervention required. One dangerous item might be a drive which * spins itself down, and come the time to write dirty pages, this * will fail, then block layer discards the data. Since we never * spin drives up, such devices simply cannot be used with ub anyway. */ if (ub_sync_tur(lun->udev, lun) != 0) { lun->changed = 1; return 1; } return lun->changed; } static struct block_device_operations ub_bd_fops = { .owner = THIS_MODULE, .open = ub_bd_open, .release = ub_bd_release, .ioctl = ub_bd_ioctl, .media_changed = ub_bd_media_changed, .revalidate_disk = ub_bd_revalidate, }; /* * Common ->done routine for commands executed synchronously. */ static void ub_probe_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd) { struct completion *cop = cmd->back; complete(cop); } /* * Test if the device has a check condition on it, synchronously. */ static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun) { struct ub_scsi_cmd *cmd; enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) }; unsigned long flags; struct completion compl; int rc; init_completion(&compl); rc = -ENOMEM; if ((cmd = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL) goto err_alloc; memset(cmd, 0, ALLOC_SIZE); cmd->cdb[0] = TEST_UNIT_READY; cmd->cdb_len = 6; cmd->dir = UB_DIR_NONE; cmd->state = UB_CMDST_INIT; cmd->lun = lun; /* This may be NULL, but that's ok */ cmd->done = ub_probe_done; cmd->back = &compl; spin_lock_irqsave(&sc->lock, flags); cmd->tag = sc->tagcnt++; rc = ub_submit_scsi(sc, cmd); spin_unlock_irqrestore(&sc->lock, flags); if (rc != 0) { printk("ub: testing ready: submit error (%d)\n", rc); /* P3 */ goto err_submit; } wait_for_completion(&compl); rc = cmd->error; if (rc == -EIO && cmd->key != 0) /* Retries for benh's key */ rc = cmd->key; err_submit: kfree(cmd); err_alloc: return rc; } /* * Read the SCSI capacity synchronously (for probing). */ static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun, struct ub_capacity *ret) { struct ub_scsi_cmd *cmd; struct scatterlist *sg; char *p; enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) + 8 }; unsigned long flags; unsigned int bsize, shift; unsigned long nsec; struct completion compl; int rc; init_completion(&compl); rc = -ENOMEM; if ((cmd = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL) goto err_alloc; memset(cmd, 0, ALLOC_SIZE); p = (char *)cmd + sizeof(struct ub_scsi_cmd); cmd->cdb[0] = 0x25; cmd->cdb_len = 10; cmd->dir = UB_DIR_READ; cmd->state = UB_CMDST_INIT; cmd->nsg = 1; sg = &cmd->sgv[0]; sg->page = virt_to_page(p); sg->offset = (unsigned long)p & (PAGE_SIZE-1); sg->length = 8; cmd->len = 8; cmd->lun = lun; cmd->done = ub_probe_done; cmd->back = &compl; spin_lock_irqsave(&sc->lock, flags); cmd->tag = sc->tagcnt++; rc = ub_submit_scsi(sc, cmd); spin_unlock_irqrestore(&sc->lock, flags); if (rc != 0) { printk("ub: reading capacity: submit error (%d)\n", rc); /* P3 */ goto err_submit; } wait_for_completion(&compl); if (cmd->error != 0) { printk("ub: reading capacity: error %d\n", cmd->error); /* P3 */ rc = -EIO; goto err_read; } if (cmd->act_len != 8) { printk("ub: reading capacity: size %d\n", cmd->act_len); /* P3 */ rc = -EIO; goto err_read; } /* sd.c special-cases sector size of 0 to mean 512. Needed? Safe? */ nsec = be32_to_cpu(*(__be32 *)p) + 1; bsize = be32_to_cpu(*(__be32 *)(p + 4)); switch (bsize) { case 512: shift = 0; break; case 1024: shift = 1; break; case 2048: shift = 2; break; case 4096: shift = 3; break; default: printk("ub: Bad sector size %u\n", bsize); /* P3 */ rc = -EDOM; goto err_inv_bsize; } ret->bsize = bsize; ret->bshift = shift; ret->nsec = nsec << shift; rc = 0; err_inv_bsize: err_read: err_submit: kfree(cmd); err_alloc: return rc; } /* */ static void ub_probe_urb_complete(struct urb *urb, struct pt_regs *pt) { struct completion *cop = urb->context; complete(cop); } static void ub_probe_timeout(unsigned long arg) { struct completion *cop = (struct completion *) arg; complete(cop); } /* * Get number of LUNs by the way of Bulk GetMaxLUN command. */ static int ub_sync_getmaxlun(struct ub_dev *sc) { int ifnum = sc->intf->cur_altsetting->desc.bInterfaceNumber; unsigned char *p; enum { ALLOC_SIZE = 1 }; struct usb_ctrlrequest *cr; struct completion compl; struct timer_list timer; int nluns; int rc; init_completion(&compl); rc = -ENOMEM; if ((p = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL) goto err_alloc; *p = 55; cr = &sc->work_cr; cr->bRequestType = USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE; cr->bRequest = US_BULK_GET_MAX_LUN; cr->wValue = cpu_to_le16(0); cr->wIndex = cpu_to_le16(ifnum); cr->wLength = cpu_to_le16(1); usb_fill_control_urb(&sc->work_urb, sc->dev, sc->recv_ctrl_pipe, (unsigned char*) cr, p, 1, ub_probe_urb_complete, &compl); sc->work_urb.actual_length = 0; sc->work_urb.error_count = 0; sc->work_urb.status = 0; if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) { if (rc == -EPIPE) { printk("%s: Stall submitting GetMaxLUN, using 1 LUN\n", sc->name); /* P3 */ } else { printk(KERN_NOTICE "%s: Unable to submit GetMaxLUN (%d)\n", sc->name, rc); } goto err_submit; } init_timer(&timer); timer.function = ub_probe_timeout; timer.data = (unsigned long) &compl; timer.expires = jiffies + UB_CTRL_TIMEOUT; add_timer(&timer); wait_for_completion(&compl); del_timer_sync(&timer); usb_kill_urb(&sc->work_urb); if ((rc = sc->work_urb.status) < 0) { if (rc == -EPIPE) { printk("%s: Stall at GetMaxLUN, using 1 LUN\n", sc->name); /* P3 */ } else { printk(KERN_NOTICE "%s: Error at GetMaxLUN (%d)\n", sc->name, rc); } goto err_io; } if (sc->work_urb.actual_length != 1) { printk("%s: GetMaxLUN returned %d bytes\n", sc->name, sc->work_urb.actual_length); /* P3 */ nluns = 0; } else { if ((nluns = *p) == 55) { nluns = 0; } else { /* GetMaxLUN returns the maximum LUN number */ nluns += 1; if (nluns > UB_MAX_LUNS) nluns = UB_MAX_LUNS; } printk("%s: GetMaxLUN returned %d, using %d LUNs\n", sc->name, *p, nluns); /* P3 */ } kfree(p); return nluns; err_io: err_submit: kfree(p); err_alloc: return rc; } /* * Clear initial stalls. */ static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe) { int endp; struct usb_ctrlrequest *cr; struct completion compl; struct timer_list timer; int rc; init_completion(&compl); endp = usb_pipeendpoint(stalled_pipe); if (usb_pipein (stalled_pipe)) endp |= USB_DIR_IN; cr = &sc->work_cr; cr->bRequestType = USB_RECIP_ENDPOINT; cr->bRequest = USB_REQ_CLEAR_FEATURE; cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT); cr->wIndex = cpu_to_le16(endp); cr->wLength = cpu_to_le16(0); usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe, (unsigned char*) cr, NULL, 0, ub_probe_urb_complete, &compl); sc->work_urb.actual_length = 0; sc->work_urb.error_count = 0; sc->work_urb.status = 0; if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) { printk(KERN_WARNING "%s: Unable to submit a probe clear (%d)\n", sc->name, rc); return rc; } init_timer(&timer); timer.function = ub_probe_timeout; timer.data = (unsigned long) &compl; timer.expires = jiffies + UB_CTRL_TIMEOUT; add_timer(&timer); wait_for_completion(&compl); del_timer_sync(&timer); usb_kill_urb(&sc->work_urb); /* reset the endpoint toggle */ usb_settoggle(sc->dev, endp, usb_pipeout(sc->last_pipe), 0); return 0; } /* * Get the pipe settings. */ static int ub_get_pipes(struct ub_dev *sc, struct usb_device *dev, struct usb_interface *intf) { struct usb_host_interface *altsetting = intf->cur_altsetting; struct usb_endpoint_descriptor *ep_in = NULL; struct usb_endpoint_descriptor *ep_out = NULL; struct usb_endpoint_descriptor *ep; int i; /* * Find the endpoints we need. * We are expecting a minimum of 2 endpoints - in and out (bulk). * We will ignore any others. */ for (i = 0; i < altsetting->desc.bNumEndpoints; i++) { ep = &altsetting->endpoint[i].desc; /* Is it a BULK endpoint? */ if ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_BULK) { /* BULK in or out? */ if (ep->bEndpointAddress & USB_DIR_IN) ep_in = ep; else ep_out = ep; } } if (ep_in == NULL || ep_out == NULL) { printk(KERN_NOTICE "%s: failed endpoint check\n", sc->name); return -EIO; } /* Calculate and store the pipe values */ sc->send_ctrl_pipe = usb_sndctrlpipe(dev, 0); sc->recv_ctrl_pipe = usb_rcvctrlpipe(dev, 0); sc->send_bulk_pipe = usb_sndbulkpipe(dev, ep_out->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK); sc->recv_bulk_pipe = usb_rcvbulkpipe(dev, ep_in->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK); return 0; } /* * Probing is done in the process context, which allows us to cheat * and not to build a state machine for the discovery. */ static int ub_probe(struct usb_interface *intf, const struct usb_device_id *dev_id) { struct ub_dev *sc; int nluns; int rc; int i; rc = -ENOMEM; if ((sc = kmalloc(sizeof(struct ub_dev), GFP_KERNEL)) == NULL) goto err_core; memset(sc, 0, sizeof(struct ub_dev)); spin_lock_init(&sc->lock); INIT_LIST_HEAD(&sc->luns); usb_init_urb(&sc->work_urb); tasklet_init(&sc->tasklet, ub_scsi_action, (unsigned long)sc); atomic_set(&sc->poison, 0); init_timer(&sc->work_timer); sc->work_timer.data = (unsigned long) sc; sc->work_timer.function = ub_urb_timeout; ub_init_completion(&sc->work_done); sc->work_done.done = 1; /* A little yuk, but oh well... */ sc->dev = interface_to_usbdev(intf); sc->intf = intf; // sc->ifnum = intf->cur_altsetting->desc.bInterfaceNumber; usb_set_intfdata(intf, sc); usb_get_dev(sc->dev); // usb_get_intf(sc->intf); /* Do we need this? */ snprintf(sc->name, 12, DRV_NAME "(%d.%d)", sc->dev->bus->busnum, sc->dev->devnum); /* XXX Verify that we can handle the device (from descriptors) */ ub_get_pipes(sc, sc->dev, intf); if (device_create_file(&sc->intf->dev, &dev_attr_diag) != 0) goto err_diag; /* * At this point, all USB initialization is done, do upper layer. * We really hate halfway initialized structures, so from the * invariants perspective, this ub_dev is fully constructed at * this point. */ /* * This is needed to clear toggles. It is a problem only if we do * `rmmod ub && modprobe ub` without disconnects, but we like that. */ #if 0 /* iPod Mini fails if we do this (big white iPod works) */ ub_probe_clear_stall(sc, sc->recv_bulk_pipe); ub_probe_clear_stall(sc, sc->send_bulk_pipe); #endif /* * The way this is used by the startup code is a little specific. * A SCSI check causes a USB stall. Our common case code sees it * and clears the check, after which the device is ready for use. * But if a check was not present, any command other than * TEST_UNIT_READY ends with a lockup (including REQUEST_SENSE). * * If we neglect to clear the SCSI check, the first real command fails * (which is the capacity readout). We clear that and retry, but why * causing spurious retries for no reason. * * Revalidation may start with its own TEST_UNIT_READY, but that one * has to succeed, so we clear checks with an additional one here. * In any case it's not our business how revaliadation is implemented. */ for (i = 0; i < 3; i++) { /* Retries for benh's key */ if ((rc = ub_sync_tur(sc, NULL)) <= 0) break; if (rc != 0x6) break; msleep(10); } nluns = 1; for (i = 0; i < 3; i++) { if ((rc = ub_sync_getmaxlun(sc)) < 0) { /* * This segment is taken from usb-storage. They say * that ZIP-100 needs this, but my own ZIP-100 works * fine without this. * Still, it does not seem to hurt anything. */ if (rc == -EPIPE) { ub_probe_clear_stall(sc, sc->recv_bulk_pipe); ub_probe_clear_stall(sc, sc->send_bulk_pipe); } break; } if (rc != 0) { nluns = rc; break; } msleep(100); } for (i = 0; i < nluns; i++) { ub_probe_lun(sc, i); } return 0; /* device_remove_file(&sc->intf->dev, &dev_attr_diag); */ err_diag: usb_set_intfdata(intf, NULL); // usb_put_intf(sc->intf); usb_put_dev(sc->dev); kfree(sc); err_core: return rc; } static int ub_probe_lun(struct ub_dev *sc, int lnum) { struct ub_lun *lun; request_queue_t *q; struct gendisk *disk; int rc; rc = -ENOMEM; if ((lun = kmalloc(sizeof(struct ub_lun), GFP_KERNEL)) == NULL) goto err_alloc; memset(lun, 0, sizeof(struct ub_lun)); lun->num = lnum; rc = -ENOSR; if ((lun->id = ub_id_get()) == -1) goto err_id; lun->udev = sc; list_add(&lun->link, &sc->luns); snprintf(lun->name, 16, DRV_NAME "%c(%d.%d.%d)", lun->id + 'a', sc->dev->bus->busnum, sc->dev->devnum, lun->num); lun->removable = 1; /* XXX Query this from the device */ lun->changed = 1; /* ub_revalidate clears only */ lun->first_open = 1; ub_revalidate(sc, lun); rc = -ENOMEM; if ((disk = alloc_disk(UB_MINORS_PER_MAJOR)) == NULL) goto err_diskalloc; lun->disk = disk; sprintf(disk->disk_name, DRV_NAME "%c", lun->id + 'a'); sprintf(disk->devfs_name, DEVFS_NAME "/%c", lun->id + 'a'); disk->major = UB_MAJOR; disk->first_minor = lun->id * UB_MINORS_PER_MAJOR; disk->fops = &ub_bd_fops; disk->private_data = lun; disk->driverfs_dev = &sc->intf->dev; rc = -ENOMEM; if ((q = blk_init_queue(ub_request_fn, &sc->lock)) == NULL) goto err_blkqinit; disk->queue = q; blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH); blk_queue_max_hw_segments(q, UB_MAX_REQ_SG); blk_queue_max_phys_segments(q, UB_MAX_REQ_SG); blk_queue_segment_boundary(q, 0xffffffff); /* Dubious. */ blk_queue_max_sectors(q, UB_MAX_SECTORS); blk_queue_hardsect_size(q, lun->capacity.bsize); q->queuedata = lun; set_capacity(disk, lun->capacity.nsec); if (lun->removable) disk->flags |= GENHD_FL_REMOVABLE; add_disk(disk); return 0; err_blkqinit: put_disk(disk); err_diskalloc: list_del(&lun->link); ub_id_put(lun->id); err_id: kfree(lun); err_alloc: return rc; } static void ub_disconnect(struct usb_interface *intf) { struct ub_dev *sc = usb_get_intfdata(intf); struct list_head *p; struct ub_lun *lun; struct gendisk *disk; unsigned long flags; /* * Prevent ub_bd_release from pulling the rug from under us. * XXX This is starting to look like a kref. * XXX Why not to take this ref at probe time? */ spin_lock_irqsave(&ub_lock, flags); sc->openc++; spin_unlock_irqrestore(&ub_lock, flags); /* * Fence stall clearnings, operations triggered by unlinkings and so on. * We do not attempt to unlink any URBs, because we do not trust the * unlink paths in HC drivers. Also, we get -84 upon disconnect anyway. */ atomic_set(&sc->poison, 1); /* * Blow away queued commands. * * Actually, this never works, because before we get here * the HCD terminates outstanding URB(s). It causes our * SCSI command queue to advance, commands fail to submit, * and the whole queue drains. So, we just use this code to * print warnings. */ spin_lock_irqsave(&sc->lock, flags); { struct ub_scsi_cmd *cmd; int cnt = 0; while ((cmd = ub_cmdq_pop(sc)) != NULL) { cmd->error = -ENOTCONN; cmd->state = UB_CMDST_DONE; ub_cmdtr_state(sc, cmd); ub_cmdq_pop(sc); (*cmd->done)(sc, cmd); cnt++; } if (cnt != 0) { printk(KERN_WARNING "%s: " "%d was queued after shutdown\n", sc->name, cnt); } } spin_unlock_irqrestore(&sc->lock, flags); /* * Unregister the upper layer. */ list_for_each (p, &sc->luns) { lun = list_entry(p, struct ub_lun, link); disk = lun->disk; if (disk->flags & GENHD_FL_UP) del_gendisk(disk); /* * I wish I could do: * set_bit(QUEUE_FLAG_DEAD, &q->queue_flags); * As it is, we rely on our internal poisoning and let * the upper levels to spin furiously failing all the I/O. */ } /* * Taking a lock on a structure which is about to be freed * is very nonsensual. Here it is largely a way to do a debug freeze, * and a bracket which shows where the nonsensual code segment ends. * * Testing for -EINPROGRESS is always a bug, so we are bending * the rules a little. */ spin_lock_irqsave(&sc->lock, flags); if (sc->work_urb.status == -EINPROGRESS) { /* janitors: ignore */ printk(KERN_WARNING "%s: " "URB is active after disconnect\n", sc->name); } spin_unlock_irqrestore(&sc->lock, flags); /* * There is virtually no chance that other CPU runs times so long * after ub_urb_complete should have called del_timer, but only if HCD * didn't forget to deliver a callback on unlink. */ del_timer_sync(&sc->work_timer); /* * At this point there must be no commands coming from anyone * and no URBs left in transit. */ device_remove_file(&sc->intf->dev, &dev_attr_diag); usb_set_intfdata(intf, NULL); // usb_put_intf(sc->intf); sc->intf = NULL; usb_put_dev(sc->dev); sc->dev = NULL; ub_put(sc); } static struct usb_driver ub_driver = { .owner = THIS_MODULE, .name = "ub", .probe = ub_probe, .disconnect = ub_disconnect, .id_table = ub_usb_ids, }; static int __init ub_init(void) { int rc; if ((rc = register_blkdev(UB_MAJOR, DRV_NAME)) != 0) goto err_regblkdev; devfs_mk_dir(DEVFS_NAME); if ((rc = usb_register(&ub_driver)) != 0) goto err_register; return 0; err_register: devfs_remove(DEVFS_NAME); unregister_blkdev(UB_MAJOR, DRV_NAME); err_regblkdev: return rc; } static void __exit ub_exit(void) { usb_deregister(&ub_driver); devfs_remove(DEVFS_NAME); unregister_blkdev(UB_MAJOR, DRV_NAME); } module_init(ub_init); module_exit(ub_exit); MODULE_LICENSE("GPL");