pf.c

优龙2410linux2.6.8内核源代码

		r = pf_completion(pf, buf, fun);
	if (r)
		pf_req_sense(pf, !fun);

	return r;
}

#define DBMSG(msg)      ((verbose>1)?(msg):NULL)

static void pf_lock(struct pf_unit *pf, int func)
{
	char lo_cmd[12] = { ATAPI_LOCK, pf->lun << 5, 0, 0, func, 0, 0, 0, 0, 0, 0, 0 };

	pf_atapi(pf, lo_cmd, 0, pf_scratch, func ? "unlock" : "lock");
}

static void pf_eject(struct pf_unit *pf)
{
	char ej_cmd[12] = { ATAPI_DOOR, pf->lun << 5, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0 };

	pf_lock(pf, 0);
	pf_atapi(pf, ej_cmd, 0, pf_scratch, "eject");
}

#define PF_RESET_TMO   30	/* in tenths of a second */

static void pf_sleep(int cs)
{
	current->state = TASK_INTERRUPTIBLE;
	schedule_timeout(cs);
}

/* the ATAPI standard actually specifies the contents of all 7 registers
   after a reset, but the specification is ambiguous concerning the last
   two bytes, and different drives interpret the standard differently.
 */

static int pf_reset(struct pf_unit *pf)
{
	int i, k, flg;
	int expect[5] = { 1, 1, 1, 0x14, 0xeb };

	pi_connect(pf->pi);
	write_reg(pf, 6, 0xa0+0x10*pf->drive);
	write_reg(pf, 7, 8);

	pf_sleep(20 * HZ / 1000);

	k = 0;
	while ((k++ < PF_RESET_TMO) && (status_reg(pf) & STAT_BUSY))
		pf_sleep(HZ / 10);

	flg = 1;
	for (i = 0; i < 5; i++)
		flg &= (read_reg(pf, i + 1) == expect[i]);

	if (verbose) {
		printk("%s: Reset (%d) signature = ", pf->name, k);
		for (i = 0; i < 5; i++)
			printk("%3x", read_reg(pf, i + 1));
		if (!flg)
			printk(" (incorrect)");
		printk("\n");
	}

	pi_disconnect(pf->pi);
	return flg - 1;
}

static void pf_mode_sense(struct pf_unit *pf)
{
	char ms_cmd[12] =
	    { ATAPI_MODE_SENSE, pf->lun << 5, 0, 0, 0, 0, 0, 0, 8, 0, 0, 0 };
	char buf[8];

	pf_atapi(pf, ms_cmd, 8, buf, DBMSG("mode sense"));
	pf->media_status = PF_RW;
	if (buf[3] & 0x80)
		pf->media_status = PF_RO;
}

static void xs(char *buf, char *targ, int offs, int len)
{
	int j, k, l;

	j = 0;
	l = 0;
	for (k = 0; k < len; k++)
		if ((buf[k + offs] != 0x20) || (buf[k + offs] != l))
			l = targ[j++] = buf[k + offs];
	if (l == 0x20)
		j--;
	targ[j] = 0;
}

static int xl(char *buf, int offs)
{
	int v, k;

	v = 0;
	for (k = 0; k < 4; k++)
		v = v * 256 + (buf[k + offs] & 0xff);
	return v;
}

static void pf_get_capacity(struct pf_unit *pf)
{
	char rc_cmd[12] = { ATAPI_CAPACITY, pf->lun << 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
	char buf[8];
	int bs;

	if (pf_atapi(pf, rc_cmd, 8, buf, DBMSG("get capacity"))) {
		pf->media_status = PF_NM;
		return;
	}
	set_capacity(pf->disk, xl(buf, 0) + 1);
	bs = xl(buf, 4);
	if (bs != 512) {
		set_capacity(pf->disk, 0);
		if (verbose)
			printk("%s: Drive %d, LUN %d,"
			       " unsupported block size %d\n",
			       pf->name, pf->drive, pf->lun, bs);
	}
}

static int pf_identify(struct pf_unit *pf)
{
	int dt, s;
	char *ms[2] = { "master", "slave" };
	char mf[10], id[18];
	char id_cmd[12] =
	    { ATAPI_IDENTIFY, pf->lun << 5, 0, 0, 36, 0, 0, 0, 0, 0, 0, 0 };
	char buf[36];

	s = pf_atapi(pf, id_cmd, 36, buf, "identify");
	if (s)
		return -1;

	dt = buf[0] & 0x1f;
	if ((dt != 0) && (dt != 7)) {
		if (verbose)
			printk("%s: Drive %d, LUN %d, unsupported type %d\n",
			       pf->name, pf->drive, pf->lun, dt);
		return -1;
	}

	xs(buf, mf, 8, 8);
	xs(buf, id, 16, 16);

	pf->removable = (buf[1] & 0x80);

	pf_mode_sense(pf);
	pf_mode_sense(pf);
	pf_mode_sense(pf);

	pf_get_capacity(pf);

	printk("%s: %s %s, %s LUN %d, type %d",
	       pf->name, mf, id, ms[pf->drive], pf->lun, dt);
	if (pf->removable)
		printk(", removable");
	if (pf->media_status == PF_NM)
		printk(", no media\n");
	else {
		if (pf->media_status == PF_RO)
			printk(", RO");
		printk(", %llu blocks\n",
			(unsigned long long)get_capacity(pf->disk));
	}
	return 0;
}

/*	returns  0, with id set if drive is detected
	        -1, if drive detection failed
*/
static int pf_probe(struct pf_unit *pf)
{
	if (pf->drive == -1) {
		for (pf->drive = 0; pf->drive <= 1; pf->drive++)
			if (!pf_reset(pf)) {
				if (pf->lun != -1)
					return pf_identify(pf);
				else
					for (pf->lun = 0; pf->lun < 8; pf->lun++)
						if (!pf_identify(pf))
							return 0;
			}
	} else {
		if (pf_reset(pf))
			return -1;
		if (pf->lun != -1)
			return pf_identify(pf);
		for (pf->lun = 0; pf->lun < 8; pf->lun++)
			if (!pf_identify(pf))
				return 0;
	}
	return -1;
}

static int pf_detect(void)
{
	struct pf_unit *pf = units;
	int k, unit;

	printk("%s: %s version %s, major %d, cluster %d, nice %d\n",
	       name, name, PF_VERSION, major, cluster, nice);

	k = 0;
	if (pf_drive_count == 0) {
		if (pi_init(pf->pi, 1, -1, -1, -1, -1, -1, pf_scratch, PI_PF,
			    verbose, pf->name)) {
			if (!pf_probe(pf) && pf->disk) {
				pf->present = 1;
				k++;
			} else
				pi_release(pf->pi);
		}

	} else
		for (unit = 0; unit < PF_UNITS; unit++, pf++) {
			int *conf = *drives[unit];
			if (!conf[D_PRT])
				continue;
			if (pi_init(pf->pi, 0, conf[D_PRT], conf[D_MOD],
				    conf[D_UNI], conf[D_PRO], conf[D_DLY],
				    pf_scratch, PI_PF, verbose, pf->name)) {
				if (!pf_probe(pf) && pf->disk) {
					pf->present = 1;
					k++;
				} else
					pi_release(pf->pi);
			}
		}
	if (k)
		return 0;

	printk("%s: No ATAPI disk detected\n", name);
	for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++)
		put_disk(pf->disk);
	return -1;
}

/* The i/o request engine */

static int pf_start(struct pf_unit *pf, int cmd, int b, int c)
{
	int i;
	char io_cmd[12] = { cmd, pf->lun << 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

	for (i = 0; i < 4; i++) {
		io_cmd[5 - i] = b & 0xff;
		b = b >> 8;
	}

	io_cmd[8] = c & 0xff;
	io_cmd[7] = (c >> 8) & 0xff;

	i = pf_command(pf, io_cmd, c * 512, "start i/o");

	mdelay(1);

	return i;
}

static int pf_ready(void)
{
	return (((status_reg(pf_current) & (STAT_BUSY | pf_mask)) == pf_mask));
}

static struct request_queue *pf_queue;

static void do_pf_request(request_queue_t * q)
{
	if (pf_busy)
		return;
repeat:
	pf_req = elv_next_request(q);
	if (!pf_req)
		return;

	pf_current = pf_req->rq_disk->private_data;
	pf_block = pf_req->sector;
	pf_run = pf_req->nr_sectors;
	pf_count = pf_req->current_nr_sectors;

	if (pf_block + pf_count > get_capacity(pf_req->rq_disk)) {
		end_request(pf_req, 0);
		goto repeat;
	}

	pf_cmd = rq_data_dir(pf_req);
	pf_buf = pf_req->buffer;
	pf_retries = 0;

	pf_busy = 1;
	if (pf_cmd == READ)
		pi_do_claimed(pf_current->pi, do_pf_read);
	else if (pf_cmd == WRITE)
		pi_do_claimed(pf_current->pi, do_pf_write);
	else {
		pf_busy = 0;
		end_request(pf_req, 0);
		goto repeat;
	}
}

static int pf_next_buf(void)
{
	unsigned long saved_flags;

	pf_count--;
	pf_run--;
	pf_buf += 512;
	pf_block++;
	if (!pf_run)
		return 0;
	if (!pf_count)
		return 1;
	spin_lock_irqsave(&pf_spin_lock, saved_flags);
	end_request(pf_req, 1);
	pf_count = pf_req->current_nr_sectors;
	pf_buf = pf_req->buffer;
	spin_unlock_irqrestore(&pf_spin_lock, saved_flags);
	return 1;
}

static inline void next_request(int success)
{
	unsigned long saved_flags;

	spin_lock_irqsave(&pf_spin_lock, saved_flags);
	end_request(pf_req, success);
	pf_busy = 0;
	do_pf_request(pf_queue);
	spin_unlock_irqrestore(&pf_spin_lock, saved_flags);
}

/* detach from the calling context - in case the spinlock is held */
static void do_pf_read(void)
{
	ps_set_intr(do_pf_read_start, NULL, 0, nice);
}

static void do_pf_read_start(void)
{
	pf_busy = 1;

	if (pf_start(pf_current, ATAPI_READ_10, pf_block, pf_run)) {
		pi_disconnect(pf_current->pi);
		if (pf_retries < PF_MAX_RETRIES) {
			pf_retries++;
			pi_do_claimed(pf_current->pi, do_pf_read_start);
			return;
		}
		next_request(0);
		return;
	}
	pf_mask = STAT_DRQ;
	ps_set_intr(do_pf_read_drq, pf_ready, PF_TMO, nice);
}

static void do_pf_read_drq(void)
{
	while (1) {
		if (pf_wait(pf_current, STAT_BUSY, STAT_DRQ | STAT_ERR,
			    "read block", "completion") & STAT_ERR) {
			pi_disconnect(pf_current->pi);
			if (pf_retries < PF_MAX_RETRIES) {
				pf_req_sense(pf_current, 0);
				pf_retries++;
				pi_do_claimed(pf_current->pi, do_pf_read_start);
				return;
			}
			next_request(0);
			return;
		}
		pi_read_block(pf_current->pi, pf_buf, 512);
		if (pf_next_buf())
			break;
	}
	pi_disconnect(pf_current->pi);
	next_request(1);
}

static void do_pf_write(void)
{
	ps_set_intr(do_pf_write_start, NULL, 0, nice);
}

static void do_pf_write_start(void)
{
	pf_busy = 1;

	if (pf_start(pf_current, ATAPI_WRITE_10, pf_block, pf_run)) {
		pi_disconnect(pf_current->pi);
		if (pf_retries < PF_MAX_RETRIES) {
			pf_retries++;
			pi_do_claimed(pf_current->pi, do_pf_write_start);
			return;
		}
		next_request(0);
		return;
	}

	while (1) {
		if (pf_wait(pf_current, STAT_BUSY, STAT_DRQ | STAT_ERR,
			    "write block", "data wait") & STAT_ERR) {
			pi_disconnect(pf_current->pi);
			if (pf_retries < PF_MAX_RETRIES) {
				pf_retries++;
				pi_do_claimed(pf_current->pi, do_pf_write_start);
				return;
			}
			next_request(0);
			return;
		}
		pi_write_block(pf_current->pi, pf_buf, 512);
		if (pf_next_buf())
			break;
	}
	pf_mask = 0;
	ps_set_intr(do_pf_write_done, pf_ready, PF_TMO, nice);
}

static void do_pf_write_done(void)
{
	if (pf_wait(pf_current, STAT_BUSY, 0, "write block", "done") & STAT_ERR) {
		pi_disconnect(pf_current->pi);
		if (pf_retries < PF_MAX_RETRIES) {
			pf_retries++;
			pi_do_claimed(pf_current->pi, do_pf_write_start);
			return;
		}
		next_request(0);
		return;
	}
	pi_disconnect(pf_current->pi);
	next_request(1);
}

static int __init pf_init(void)
{				/* preliminary initialisation */
	struct pf_unit *pf;
	int unit;

	if (disable)
		return -1;

	pf_init_units();

	if (pf_detect())
		return -1;
	pf_busy = 0;

	if (register_blkdev(major, name)) {
		for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++)
			put_disk(pf->disk);
		return -1;
	}
	pf_queue = blk_init_queue(do_pf_request, &pf_spin_lock);
	if (!pf_queue) {
		unregister_blkdev(major, name);
		for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++)
			put_disk(pf->disk);
		return -1;
	}

	blk_queue_max_phys_segments(pf_queue, cluster);
	blk_queue_max_hw_segments(pf_queue, cluster);

	for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++) {
		struct gendisk *disk = pf->disk;

		if (!pf->present)
			continue;
		disk->private_data = pf;
		disk->queue = pf_queue;
		add_disk(disk);
	}
	return 0;
}

static void __exit pf_exit(void)
{
	struct pf_unit *pf;
	int unit;
	unregister_blkdev(major, name);
	for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++) {
		if (!pf->present)
			continue;
		del_gendisk(pf->disk);
		put_disk(pf->disk);
		pi_release(pf->pi);
	}
	blk_cleanup_queue(pf_queue);
}

MODULE_LICENSE("GPL");
module_init(pf_init)
module_exit(pf_exit)