/*
* The driver enables interrupts as much as possible. In order to do this,
* (a) the device-interrupt is disabled before entering hd_request(),
* and (b) the timeout-interrupt is disabled before the sti().
*
* Interrupts are still masked (by default) whenever we are exchanging
* data/cmds with a drive, because some drives seem to have very poor
* tolerance for latency during I/O. The IDE driver has support to unmask
* interrupts for non-broken hardware, so use that driver if required.
*/
static void hd_request(void)
{
unsigned int block, nsect, sec, track, head, cyl;
struct hd_i_struct *disk;
struct request *req;
if (do_hd)
return;
repeat:
del_timer(&device_timer);
if (!hd_req) {
hd_req = blk_fetch_request(hd_queue);
if (!hd_req) {
do_hd = NULL;
return;
}
}
req = hd_req;
if (reset) {
reset_hd();
return;
}
disk = req->rq_disk->private_data;
block = blk_rq_pos(req);
nsect = blk_rq_sectors(req);
if (block >= get_capacity(req->rq_disk) ||
((block+nsect) > get_capacity(req->rq_disk))) {
printk("%s: bad access: block=%d, count=%d\n",
req->rq_disk->disk_name, block, nsect);
hd_end_request_cur(-EIO);
goto repeat;
}
if (disk->special_op) {
if (do_special_op(disk, req))
goto repeat;
return;
}
sec = block % disk->sect + 1;
track = block / disk->sect;
head = track % disk->head;
cyl = track / disk->head;
#ifdef DEBUG
printk("%s: %sing: CHS=%d/%d/%d, sectors=%d, buffer=%p\n",
req->rq_disk->disk_name,
req_data_dir(req) == READ ? "read" : "writ",
cyl, head, sec, nsect, req->buffer);
#endif
<<<<<<< HEAD
static int do_special_op(struct hd_i_struct *disk, struct request *req)
{
if (disk->recalibrate) {
disk->recalibrate = 0;
hd_out(disk, disk->sect, 0, 0, 0, ATA_CMD_RESTORE, &recal_intr);
return reset;
}
if (disk->head > 16) {
printk("%s: cannot handle device with more than 16 heads - giving up\n", req->rq_disk->disk_name);
hd_end_request_cur(-EIO);
}
disk->special_op = 0;
return 1;
}
/* * bad_rw_intr() now tries to be a bit smarter and does things * according to the error returned by the controller. * -Mika Liljeberg ([email protected]) */ static void bad_rw_intr(void) { struct request *req = hd_req; if (req != NULL) { struct hd_i_struct *disk = req->rq_disk->private_data; if (++req->errors >= MAX_ERRORS || (hd_error & BBD_ERR)) { hd_end_request_cur(-EIO); disk->special_op = disk->recalibrate = 1; } else if (req->errors % RESET_FREQ == 0) reset = 1; else if ((hd_error & TRK0_ERR) || req->errors % RECAL_FREQ == 0) disk->special_op = disk->recalibrate = 1; /* Otherwise just retry */ } }
/*
* This is another of the error-routines I don't know what to do with. The
* best idea seems to just set reset, and start all over again.
*/
static void hd_times_out(unsigned long dummy)
{
char *name;
do_hd = NULL;
if (!hd_req)
return;
spin_lock_irq(hd_queue->queue_lock);
reset = 1;
name = hd_req->rq_disk->disk_name;
printk("%s: timeout\n", name);
if (++hd_req->errors >= MAX_ERRORS) {
#ifdef DEBUG
printk("%s: too many errors\n", name);
#endif
hd_end_request_cur(-EIO);
}
hd_request();
spin_unlock_irq(hd_queue->queue_lock);
}
/*
* The driver enables interrupts as much as possible. In order to do this,
* (a) the device-interrupt is disabled before entering hd_request(),
* and (b) the timeout-interrupt is disabled before the sti().
*
* Interrupts are still masked (by default) whenever we are exchanging
* data/cmds with a drive, because some drives seem to have very poor
* tolerance for latency during I/O. The IDE driver has support to unmask
* interrupts for non-broken hardware, so use that driver if required.
*/
static void hd_request(void)
{
unsigned int block, nsect, sec, track, head, cyl;
struct hd_i_struct *disk;
struct request *req;
if (do_hd)
return;
repeat:
del_timer(&device_timer);
if (!hd_req) {
hd_req = blk_fetch_request(hd_queue);
if (!hd_req) {
do_hd = NULL;
return;
}
}
req = hd_req;
if (reset) {
reset_hd();
return;
}
disk = req->rq_disk->private_data;
block = blk_rq_pos(req);
nsect = blk_rq_sectors(req);
if (block >= get_capacity(req->rq_disk) ||
((block+nsect) > get_capacity(req->rq_disk))) {
printk("%s: bad access: block=%d, count=%d\n",
req->rq_disk->disk_name, block, nsect);
hd_end_request_cur(-EIO);
goto repeat;
}
if (disk->special_op) {
if (do_special_op(disk, req))
goto repeat;
return;
}
sec = block % disk->sect + 1;
track = block / disk->sect;
head = track % disk->head;
cyl = track / disk->head;
#ifdef DEBUG
printk("%s: %sing: CHS=%d/%d/%d, sectors=%d, buffer=%p\n",
req->rq_disk->disk_name,
req_data_dir(req) == READ ? "read" : "writ",
cyl, head, sec, nsect, req->buffer);
#endif
if (blk_fs_request(req)) {
switch (rq_data_dir(req)) {
case READ:
hd_out(disk, nsect, sec, head, cyl, ATA_CMD_PIO_READ,
&read_intr);
if (reset)
goto repeat;
break;
case WRITE:
hd_out(disk, nsect, sec, head, cyl, ATA_CMD_PIO_WRITE,
&write_intr);
if (reset)
goto repeat;
if (wait_DRQ()) {
bad_rw_intr();
goto repeat;
}
outsw(HD_DATA, req->buffer, 256);
break;
default:
printk("unknown hd-command\n");
hd_end_request_cur(-EIO);
break;
}
}
}