diff options
Diffstat (limited to 'drivers/block/ub.c')
| -rw-r--r-- | drivers/block/ub.c | 2215 |
1 files changed, 2215 insertions, 0 deletions
diff --git a/drivers/block/ub.c b/drivers/block/ub.c new file mode 100644 index 000000000000..ce42889f98fb --- /dev/null +++ b/drivers/block/ub.c @@ -0,0 +1,2215 @@ +/* + * 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) + * -- 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) + * -- support pphaneuf's SDDR-75 with two LUNs (also broken capacity...) + * -- special case some senses, e.g. 3a/0 -> no media present, reduce retries + * -- verify the 13 conditions and do bulk resets + * -- normal pool of commands instead of cmdv[]? + * -- kill last_pipe and simply do two-state clearing on both pipes + * -- verify protocol (bulk) from USB descriptors (maybe...) + * -- highmem and sg + * -- move top_sense and work_bcs into separate allocations (if they survive) + * for cache purists and esoteric architectures. + * -- 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=? + */ +#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 + +/* + * 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 */ + +/* + */ +#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 normally 0 */ + 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' */ +/* This is for Olympus Camedia digital cameras */ +#define US_BULK_CS_OLYMPUS_SIGN 0x55425355 /* spells out 'USBU' */ +#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 1 +#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_SENSE, /* Sending Request Sense */ + UB_CMDST_DONE /* Final state */ +}; + +static char *ub_scsi_cmd_stname[] = { + ". ", + "Cmd", + "dat", + "c2s", + "sts", + "clr", + "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. */ + + /* + * We do not support transfers from highmem pages + * because the underlying USB framework does not do what we need. + */ + char *data; /* Requested buffer */ + unsigned int len; /* Requested length */ + // struct scatterlist sgv[UB_MAX_REQ_SG]; + + 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 UB device instance. + */ +struct ub_dev { + spinlock_t lock; + int id; /* Number among ub's */ + atomic_t poison; /* The USB device is disconnected */ + int openc; /* protected by ub_lock! */ + /* kref is too implicit for our taste */ + unsigned int tagcnt; + int changed; /* Media was changed */ + int removable; + int readonly; + int first_open; /* Kludge. See ub_bd_open. */ + char name[8]; + struct usb_device *dev; + struct usb_interface *intf; + + struct ub_capacity capacity; + struct gendisk *disk; + + 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; + + /* XXX Use Ingo's mempool (once we have more than one) */ + int cmda[1]; + struct ub_scsi_cmd cmdv[1]; + + 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 */ + struct bulk_cb_wrap work_bcb; + struct bulk_cs_wrap work_bcs; + struct usb_ctrlrequest work_cr; + + struct ub_scsi_trace tr; +}; + +/* + */ +static void ub_cleanup(struct ub_dev *sc); +static int ub_bd_rq_fn_1(struct ub_dev *sc, struct request *rq); +static int ub_cmd_build_block(struct ub_dev *sc, struct ub_scsi_cmd *cmd, + struct request *rq); +static int ub_cmd_build_packet(struct ub_dev *sc, 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_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc); +static void __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_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); +static int ub_sync_read_cap(struct ub_dev *sc, struct ub_capacity *ret); + +/* + */ +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, char *page) +{ + struct usb_interface *intf; + struct ub_dev *sc; + 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 changed %d removable %d readonly %d\n", + sc->cmd_queue.qlen, sc->cmd_queue.qmax, + sc->changed, sc->removable, sc->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) +{ + request_queue_t *q; + + /* I don't think queue can be NULL. But... Stolen from sx8.c */ + if ((q = sc->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(sc->disk); + sc->disk = NULL; + + ub_id_put(sc->id); + kfree(sc); +} + +/* + * The "command allocator". + */ +static struct ub_scsi_cmd *ub_get_cmd(struct ub_dev *sc) +{ + struct ub_scsi_cmd *ret; + + if (sc->cmda[0]) + return NULL; + ret = &sc->cmdv[0]; + sc->cmda[0] = 1; + return ret; +} + +static void ub_put_cmd(struct ub_dev *sc, struct ub_scsi_cmd *cmd) +{ + if (cmd != &sc->cmdv[0]) { + printk(KERN_WARNING "%s: releasing a foreign cmd %p\n", + sc->name, cmd); + return; + } + if (!sc->cmda[0]) { + printk(KERN_WARNING "%s: releasing a free cmd\n", sc->name); + return; + } + sc->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_bd_rq_fn(request_queue_t *q) +{ + struct ub_dev *sc = q->queuedata; + struct request *rq; + + while ((rq = elv_next_request(q)) != NULL) { + if (ub_bd_rq_fn_1(sc, rq) != 0) { + blk_stop_queue(q); + break; + } + } +} + +static int ub_bd_rq_fn_1(struct ub_dev *sc, struct request *rq) +{ + struct ub_scsi_cmd *cmd; + int rc; + + if (atomic_read(&sc->poison) || sc->changed) { + blkdev_dequeue_request(rq); + ub_end_rq(rq, 0); + return 0; + } + + if ((cmd = ub_get_cmd(sc)) == 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, cmd, rq); + } else { + rc = ub_cmd_build_block(sc, cmd, rq); + } + if (rc != 0) { + ub_put_cmd(sc, cmd); + ub_end_rq(rq, 0); + blk_start_queue(sc->disk->queue); + return 0; + } + + cmd->state = UB_CMDST_INIT; + cmd->done = ub_rw_cmd_done; + cmd->back = rq; + + cmd->tag = sc->tagcnt++; + if ((rc = ub_submit_scsi(sc, cmd)) != 0) { + ub_put_cmd(sc, cmd); + ub_end_rq(rq, 0); + blk_start_queue(sc->disk->queue); + return 0; + } + + return 0; +} + +static int ub_cmd_build_block(struct ub_dev *sc, struct ub_scsi_cmd *cmd, + struct request *rq) +{ + int ub_dir; +#if 0 /* We use rq->buffer for now */ + struct scatterlist *sg; + int n_elem; +#endif + unsigned int block, nblks; + + if (rq_data_dir(rq) == WRITE) + ub_dir = UB_DIR_WRITE; + else + ub_dir = UB_DIR_READ; + + /* + * get scatterlist from block layer + */ +#if 0 /* We use rq->buffer for now */ + sg = &cmd->sgv[0]; + n_elem = blk_rq_map_sg(q, rq, sg); + if (n_elem <= 0) { + ub_put_cmd(sc, cmd); + ub_end_rq(rq, 0); + blk_start_queue(q); + return 0; /* request with no s/g entries? */ + } + + if (n_elem != 1) { /* Paranoia */ + printk(KERN_WARNING "%s: request with %d segments\n", + sc->name, n_elem); + ub_put_cmd(sc, cmd); + ub_end_rq(rq, 0); + blk_start_queue(q); + return 0; + } +#endif + + /* + * XXX Unfortunately, this check does not work. It is quite possible + * to get bogus non-null rq->buffer if you allow sg by mistake. + */ + if (rq->buffer == NULL) { + /* + * This must not happen if we set the queue right. + * The block level must create bounce buffers for us. + */ + static int do_print = 1; + if (do_print) { + printk(KERN_WARNING "%s: unmapped block request" + " flags 0x%lx sectors %lu\n", + sc->name, rq->flags, rq->nr_sectors); + do_print = 0; + } + return -1; + } + + /* + * 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 >> sc->capacity.bshift; + nblks = rq->nr_sectors >> sc->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->dir = ub_dir; + cmd->data = rq->buffer; + cmd->len = rq->nr_sectors * 512; + + return 0; +} + +static int ub_cmd_build_packet(struct ub_dev *sc, struct ub_scsi_cmd *cmd, + struct request *rq) +{ + + if (rq->data_len != 0 && rq->data == NULL) { + static int do_print = 1; + if (do_print) { + printk(KERN_WARNING "%s: unmapped packet request" + " flags 0x%lx length %d\n", + sc->name, rq->flags, rq->data_len); + do_print = 0; + } + return -1; + } + + memcpy(&cmd->cdb, rq->cmd, rq->cmd_len); + cmd->cdb_len = rq->cmd_len; + + 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; + } + cmd->data = rq->data; + 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 gendisk *disk = sc->disk; + request_queue_t *q = disk->queue; + int uptodate; + + 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 (cmd->error == 0) + uptodate = 1; + else + uptodate = 0; + + ub_put_cmd(sc, cmd); + ub_end_rq(rq, uptodate); + blk_start_queue(q); +} + +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 = 0; /* No multi-LUN yet */ + 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); + sc->work_urb.transfer_flags = URB_ASYNC_UNLINK; + + /* 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 */ + printk("ub: cmd #%d start failed (%d)\n", cmd->tag, rc); /* P3 */ + 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 pipe; + 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 for device %u\n", + sc->name, sc->dev->devnum); + 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 for device %u\n", + sc->name, sc->dev->devnum); + 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_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 for device %u" + " (code %d)\n", + sc->name, sc->dev->devnum, 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) { + printk("ub: cmd #%d cmd status (%d)\n", cmd->tag, urb->status); /* P3 */ + goto Bad_End; + } + if (urb->actual_length != US_BULK_CB_WRAP_LEN) { + printk("ub: cmd #%d xferred %d\n", cmd->tag, urb->actual_length); /* P3 */ + /* XXX Must do reset here to unconfuse the device */ + goto Bad_End; + } + + if (cmd->dir == UB_DIR_NONE) { + ub_state_stat(sc, cmd); + return; + } + + 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, + cmd->data, cmd->len, ub_urb_complete, sc); + sc->work_urb.transfer_flags = URB_ASYNC_UNLINK; + 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 */ + printk("ub: data #%d submit failed (%d)\n", cmd->tag, rc); /* P3 */ + 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); + + } 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 for device %u" + " (code %d)\n", + sc->name, sc->dev->devnum, 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. + */ + cmd->error = -EOVERFLOW; /* A cheap trick... */ + } else { + if (urb->status != 0) + goto Bad_End; + } + + cmd->act_len = urb->actual_length; + ub_cmdtr_act_len(sc, cmd); + + 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 for device %u" + " (code %d)\n", + sc->name, sc->dev->devnum, 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 == 0) { + /* + * Some broken devices add unnecessary zero-length + * packets to the end of their data transfers. + * Such packets show up as 0-length CSWs. If we + * encounter such a thing, try to read the CSW again. + */ + if (++cmd->stat_count >= 4) { + printk(KERN_NOTICE "%s: " + "unable to get CSW on device %u\n", + sc->name, sc->dev->devnum); + goto Bad_End; + } + __ub_state_stat(sc, cmd); + return; + } + + /* + * Check the returned Bulk protocol status. + */ + + bcs = &sc->work_bcs; + 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; + } + +#if 0 + if (bcs->Signature != cpu_to_le32(US_BULK_CS_SIGN) && + bcs->Signature != cpu_to_le32(US_BULK_CS_OLYMPUS_SIGN)) { + /* Windows ignores signatures, so do we. */ + } +#endif + + 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. + */ + if (++cmd->stat_count >= 4) { + printk(KERN_NOTICE "%s: " + "tag mismatch orig 0x%x reply 0x%x " + "on device %u\n", + sc->name, cmd->tag, bcs->Tag, + sc->dev->devnum); + goto Bad_End; + } + __ub_state_stat(sc, cmd); + return; + } + + 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 */ + 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 on device %u\n", + sc->name, cmd->state, sc->dev->devnum); + goto Bad_End; + } + return; + +Bad_End: /* Little Excel is dead */ + ub_state_done(sc, cmd, -EIO); +} + +/* + * 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 void __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.transfer_flags = URB_ASYNC_UNLINK; + 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 */ + printk("%s: CSW #%d submit failed (%d)\n", sc->name, cmd->tag, rc); /* P3 */ + ub_complete(&sc->work_done); + ub_state_done(sc, cmd, rc); + return; + } + + sc->work_timer.expires = jiffies + UB_STAT_TIMEOUT; + add_timer(&sc->work_timer); +} + +/* + * 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) +{ + __ub_state_stat(sc, cmd); + + cmd->stat_count = 0; + 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; + int rc; + + if (cmd->cdb[0] == REQUEST_SENSE) { + rc = -EPIPE; + goto error; + } + + scmd = &sc->top_rqs_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->data = sc->top_sense; + scmd->len = UB_SENSE_SIZE; + 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.transfer_flags = URB_ASYNC_UNLINK; + 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 = scmd->data; + 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 on device %u\n", + sc->name, cmd->tag, sc->dev->devnum); + return; + } + if (cmd->state != UB_CMDST_SENSE) { + printk(KERN_WARNING "%s: " + "sense done with bad cmd state %d on device %u\n", + sc->name, cmd->state, sc->dev->devnum); + return; + } + + cmd->key = sense[2] & 0x0F; + cmd->asc = sense[12]; + cmd->ascq = sense[13]; + + ub_scsi_urb_compl(sc, cmd); +} + +#if 0 +/* Determine what the maximum LUN supported is */ +int usb_stor_Bulk_max_lun(struct us_data *us) +{ + int result; + + /* issue the command */ + result = usb_stor_control_msg(us, us->recv_ctrl_pipe, + US_BULK_GET_MAX_LUN, + USB_DIR_IN | USB_TYPE_CLASS | + USB_RECIP_INTERFACE, + 0, us->ifnum, us->iobuf, 1, HZ); + + /* + * Some devices (i.e. Iomega Zip100) need this -- apparently + * the bulk pipes get STALLed when the GetMaxLUN request is + * processed. This is, in theory, harmless to all other devices + * (regardless of if they stall or not). + */ + if (result < 0) { + usb_stor_clear_halt(us, us->recv_bulk_pipe); + usb_stor_clear_halt(us, us->send_bulk_pipe); + } + + US_DEBUGP("GetMaxLUN command result is %d, data is %d\n", + result, us->iobuf[0]); + + /* if we have a successful request, return the result */ + if (result == 1) + return us->iobuf[0]; + + /* return the default -- no LUNs */ + return 0; +} +#endif + +/* + * This is called from a process context. + */ +static void ub_revalidate(struct ub_dev *sc) +{ + + sc->readonly = 0; /* XXX Query this from the device */ + + sc->capacity.nsec = 0; + sc->capacity.bsize = 512; + sc->capacity.bshift = 0; + + if (ub_sync_tur(sc) != 0) + return; /* Not ready */ + sc->changed = 0; + + if (ub_sync_read_cap(sc, &sc->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, &sc->capacity) != 0) { + sc->capacity.nsec = 0; + sc->capacity.bsize = 512; + sc->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_dev *sc; + unsigned long flags; + int rc; + + if ((sc = disk->private_data) == NULL) + return -ENXIO; + 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 (sc->first_open) { + if (sc->changed) { + sc->first_open = 0; + rc = -ENOMEDIUM; + goto err_open; + } + } + + if (sc->removable || sc->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 (sc->removable && sc->changed && !(filp->f_flags & O_NDELAY)) { + rc = -ENOMEDIUM; + goto err_open; + } + + if (sc->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_dev *sc = disk->private_data; + + 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_dev *sc = disk->private_data; + + ub_revalidate(sc); + /* This is pretty much a long term P3 */ + if (!atomic_read(&sc->poison)) { /* Cover sc->dev */ + printk(KERN_INFO "%s: device %u capacity nsec %ld bsize %u\n", + sc->name, sc->dev->devnum, + sc->capacity.nsec, sc->capacity.bsize); + } + + /* XXX Support sector size switching like in sr.c */ + blk_queue_hardsect_size(disk->queue, sc->capacity.bsize); + set_capacity(disk, sc->capacity.nsec); + // set_disk_ro(sdkp->disk, sc->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_dev *sc = disk->private_data; + + if (!sc->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(sc) != 0) { + sc->changed = 1; + return 1; + } + + return sc->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_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->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_capacity *ret) +{ + struct ub_scsi_cmd *cmd; + 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->data = p; + cmd->len = 8; + 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); +} + +/* + * 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.transfer_flags = 0; + 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: device %u failed endpoint check\n", + sc->name, sc->dev->devnum); + 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; + request_queue_t *q; + struct gendisk *disk; + 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); + 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... */ + + rc = -ENOSR; + if ((sc->id = ub_id_get()) == -1) + goto err_id; + snprintf(sc->name, 8, DRV_NAME "%c", sc->id + 'a'); + + 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? */ + + /* 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. + */ + ub_probe_clear_stall(sc, sc->recv_bulk_pipe); + ub_probe_clear_stall(sc, sc->send_bulk_pipe); + + /* + * 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)) <= 0) break; + if (rc != 0x6) break; + msleep(10); + } + + sc->removable = 1; /* XXX Query this from the device */ + sc->changed = 1; /* ub_revalidate clears only */ + sc->first_open = 1; + + ub_revalidate(sc); + /* This is pretty much a long term P3 */ + printk(KERN_INFO "%s: device %u capacity nsec %ld bsize %u\n", + sc->name, sc->dev->devnum, sc->capacity.nsec, sc->capacity.bsize); + + /* + * Just one disk per sc currently, but maybe more. + */ + rc = -ENOMEM; + if ((disk = alloc_disk(UB_MINORS_PER_MAJOR)) == NULL) + goto err_diskalloc; + + sc->disk = disk; + sprintf(disk->disk_name, DRV_NAME "%c", sc->id + 'a'); + sprintf(disk->devfs_name, DEVFS_NAME "/%c", sc->id + 'a'); + disk->major = UB_MAJOR; + disk->first_minor = sc->id * UB_MINORS_PER_MAJOR; + disk->fops = &ub_bd_fops; + disk->private_data = sc; + disk->driverfs_dev = &intf->dev; + + rc = -ENOMEM; + if ((q = blk_init_queue(ub_bd_rq_fn, &sc->lock)) == NULL) + goto err_blkqinit; + + disk->queue = q; + + // blk_queue_bounce_limit(q, hba[i]->pdev->dma_mask); + 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, CARM_SG_BOUNDARY); + blk_queue_max_sectors(q, UB_MAX_SECTORS); + blk_queue_hardsect_size(q, sc->capacity.bsize); + + /* + * This is a serious infraction, caused by a deficiency in the + * USB sg interface (usb_sg_wait()). We plan to remove this once + * we get mileage on the driver and can justify a change to USB API. + * See blk_queue_bounce_limit() to understand this part. + * + * XXX And I still need to be aware of the DMA mask in the HC. + */ + q->bounce_pfn = blk_max_low_pfn; + q->bounce_gfp = GFP_NOIO; + + q->queuedata = sc; + + set_capacity(disk, sc->capacity.nsec); + if (sc->removable) + disk->flags |= GENHD_FL_REMOVABLE; + + add_disk(disk); + + return 0; + +err_blkqinit: + put_disk(disk); +err_diskalloc: + 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); + ub_id_put(sc->id); +err_id: + kfree(sc); +err_core: + return rc; +} + +static void ub_disconnect(struct usb_interface *intf) +{ + struct ub_dev *sc = usb_get_intfdata(intf); + struct gendisk *disk = sc->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. + */ + 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; + + /* P3 */ printk("ub: sizeof ub_scsi_cmd %zu ub_dev %zu\n", + sizeof(struct ub_scsi_cmd), sizeof(struct ub_dev)); + + 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"); |
