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Commit a1cf96ef authored by Pete Zaitcev's avatar Pete Zaitcev Committed by Greg Kroah-Hartman
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[PATCH] USB: ub 4: Zaitcev's quasi-S/G 

Back out Axboe-style quasi-S/G and replace it with one command and
repeated URBs. This is similar to what usb-storage does, only instead
of a few URBs allocated together, one URB is reused.

Jens's idea was very nice, but it collapsed when I had to support
packet commads for CD burning. I cannot issue two or more packet
commands where application expected only one.

However, burning does not work completely yet. The cdrecord starts,
recognizes the device, then aborts without writing a TOC.
Signed-off-by: default avatarPete Zaitcev <zaitcev@yahoo.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 6c1eb8c1
Show whitespace changes
Inline Side-by-side
Showing with 123 additions and 164 deletions
drivers/block/ub.c
View file @ a1cf96ef
......@@ -235,27 +235,16 @@ struct ub_scsi_cmd {
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 */
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_request {
struct request *rq;
unsigned char dir;
unsigned int current_block;
unsigned int current_sg;
unsigned int nsg; /* sgv[nsg] */
struct scatterlist sgv[UB_MAX_REQ_SG];
};
/*
*/
struct ub_capacity {
......@@ -351,8 +340,6 @@ struct ub_lun {
int readonly;
int first_open; /* Kludge. See ub_bd_open. */
struct ub_request urq;
/* 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.
......@@ -410,19 +397,16 @@ 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 void ub_scsi_build_block(struct ub_lun *lun,
struct ub_scsi_cmd *cmd, struct ub_request *urq);
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_request_advance(struct ub_dev *sc, struct ub_lun *lun,
struct ub_request *urq, struct ub_scsi_cmd *cmd);
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);
......@@ -793,8 +777,6 @@ static int ub_request_fn_1(struct ub_lun *lun, struct request *rq)
return 0;
}
if (lun->urq.rq != NULL)
return -1;
if ((cmd = ub_get_cmd(lun)) == NULL)
return -1;
memset(cmd, 0, sizeof(struct ub_scsi_cmd));
......@@ -813,7 +795,7 @@ static int ub_request_fn_1(struct ub_lun *lun, struct request *rq)
cmd->state = UB_CMDST_INIT;
cmd->lun = lun;
cmd->done = ub_rw_cmd_done;
cmd->back = &lun->urq;
cmd->back = rq;
cmd->tag = sc->tagcnt++;
if (ub_submit_scsi(sc, cmd) != 0) {
......@@ -828,22 +810,20 @@ 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)
{
struct ub_request *urq;
int ub_dir;
int n_elem;
urq = &lun->urq;
memset(urq, 0, sizeof(struct ub_request));
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, &urq->sgv[0]);
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 */
......@@ -854,7 +834,7 @@ static int ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
sc->name, n_elem);
return -1;
}
urq->nsg = n_elem;
cmd->nsg = n_elem;
sc->sg_stat[n_elem]++;
/*
......@@ -863,29 +843,10 @@ static int ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
* The call to blk_queue_hardsect_size() guarantees that request
* is aligned, but it is given in terms of 512 byte units, always.
*/
urq->current_block = rq->sector >> lun->capacity.bshift;
// nblks = rq->nr_sectors >> lun->capacity.bshift;
block = rq->sector >> lun->capacity.bshift;
nblks = rq->nr_sectors >> lun->capacity.bshift;
urq->rq = rq;
urq->current_sg = 0;
urq->dir = ub_dir;
ub_scsi_build_block(lun, cmd, urq);
return 0;
}
static void ub_scsi_build_block(struct ub_lun *lun,
struct ub_scsi_cmd *cmd, struct ub_request *urq)
{
struct scatterlist *sg;
unsigned int block, nblks;
sg = &urq->sgv[urq->current_sg];
block = urq->current_block;
nblks = sg->length >> (lun->capacity.bshift + 9);
cmd->cdb[0] = (urq->dir == UB_DIR_READ)? READ_10: WRITE_10;
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;
......@@ -895,34 +856,15 @@ static void ub_scsi_build_block(struct ub_lun *lun,
cmd->cdb[8] = nblks;
cmd->cdb_len = 10;
cmd->dir = urq->dir;
cmd->data = page_address(sg->page) + sg->offset;
cmd->len = sg->length;
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)
{
struct ub_request *urq;
urq = &lun->urq;
memset(urq, 0, sizeof(struct ub_request));
urq->rq = rq;
sc->sg_stat[0]++;
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;
int n_elem;
if (rq->data_len == 0) {
cmd->dir = UB_DIR_NONE;
......@@ -931,8 +873,29 @@ static int ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
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;
}
cmd->data = rq->data;
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]++;
memcpy(&cmd->cdb, rq->cmd, rq->cmd_len);
cmd->cdb_len = rq->cmd_len;
cmd->len = rq->data_len;
return 0;
......@@ -940,34 +903,33 @@ static int ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
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;
struct ub_request *urq = cmd->back;
struct request *rq;
int uptodate;
rq = urq->rq;
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 (cmd->error == 0)
uptodate = 1;
if (sc->top_sense[0] != 0)
rq->errors = SAM_STAT_CHECK_CONDITION;
else
uptodate = 0;
if (cmd->error == 0 && urq->current_sg+1 < urq->nsg) {
if (ub_request_advance(sc, lun, urq, cmd) == 0) {
/* Stay on target... */
return;
rq->errors = DID_ERROR << 16;
}
uptodate = 0;
}
urq->rq = NULL;
ub_put_cmd(lun, cmd);
ub_end_rq(rq, uptodate);
blk_start_queue(lun->disk->queue);
......@@ -982,40 +944,6 @@ static void ub_end_rq(struct request *rq, int uptodate)
end_that_request_last(rq);
}
static int ub_request_advance(struct ub_dev *sc, struct ub_lun *lun,
struct ub_request *urq, struct ub_scsi_cmd *cmd)
{
struct scatterlist *sg;
unsigned int nblks;
/* XXX This is temporary, until we sort out S/G in packet requests. */
if (blk_pc_request(urq->rq)) {
printk(KERN_WARNING
"2-segment packet request completed\n"); /* P3 */
return -1;
}
sg = &urq->sgv[urq->current_sg];
nblks = sg->length >> (lun->capacity.bshift + 9);
urq->current_block += nblks;
urq->current_sg++;
sg++;
memset(cmd, 0, sizeof(struct ub_scsi_cmd));
ub_scsi_build_block(lun, cmd, urq);
cmd->state = UB_CMDST_INIT;
cmd->lun = lun;
cmd->done = ub_rw_cmd_done;
cmd->back = &lun->urq;
cmd->tag = sc->tagcnt++;
if (ub_submit_scsi(sc, cmd) != 0) {
return -1;
}
return 0;
}
/*
* Submit a regular SCSI operation (not an auto-sense).
*
......@@ -1171,7 +1099,6 @@ 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)) {
......@@ -1272,38 +1199,13 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
goto Bad_End;
}
if (cmd->dir == UB_DIR_NONE) {
if (cmd->dir == UB_DIR_NONE || cmd->nsg < 1) {
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);
// udelay(125); // usb-storage has this
ub_data_start(sc, cmd);
} else if (cmd->state == UB_CMDST_DATA) {
if (urb->status == -EPIPE) {
......@@ -1325,16 +1227,22 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
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... */
} else {
ub_state_stat(sc, cmd);
return;
}
if (urb->status != 0)
goto Bad_End;
}
cmd->act_len = urb->actual_length;
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) {
......@@ -1467,6 +1375,46 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
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.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);
}
/*
* Factorization helper for the command state machine:
* Finish the command.
......@@ -1552,6 +1500,7 @@ 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)
{
struct ub_scsi_cmd *scmd;
struct scatterlist *sg;
int rc;
if (cmd->cdb[0] == REQUEST_SENSE) {
......@@ -1560,12 +1509,17 @@ static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
}
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->data = sc->top_sense;
scmd->nsg = 1;
sg = &scmd->sgv[0];
sg->page = virt_to_page(sc->top_sense);
sg->offset = (unsigned int)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;
......@@ -1628,7 +1582,7 @@ static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
*/
static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd)
{
unsigned char *sense = scmd->data;
unsigned char *sense = sc->top_sense;
struct ub_scsi_cmd *cmd;
/*
......@@ -1920,6 +1874,7 @@ 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;
......@@ -1940,7 +1895,11 @@ static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
cmd->cdb_len = 10;
cmd->dir = UB_DIR_READ;
cmd->state = UB_CMDST_INIT;
cmd->data = p;
cmd->nsg = 1;
sg = &cmd->sgv[0];
sg->page = virt_to_page(p);
sg->offset = (unsigned int)p & (PAGE_SIZE-1);
sg->length = 8;
cmd->len = 8;
cmd->lun = lun;
cmd->done = ub_probe_done;
......
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