ofw/libofw/ofw_disk.c

	ofw_disk.c revision 199767f8919635c4928607450d9e0abb932109ce
/*-
 * Copyright (C) 2000 Benno Rice.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY Benno Rice ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

/*
 * Disk I/O routines using Open Firmware
 */

#include <sys/param.h>

#include <netinet/in.h>

#include <machine/stdarg.h>

#include <stand.h>

#include "bootstrap.h"
#include "libofw.h"

static int  ofwd_init(void);
static int  ofwd_strategy(void *devdata, int flag, daddr_t dblk,
            size_t size, char *buf, size_t *rsize);
static int  ofwd_open(struct open_file *f, ...);
static int  ofwd_close(struct open_file *f);
static int  ofwd_ioctl(struct open_file *f, u_long cmd, void *data);
static void ofwd_print(int verbose);

struct devsw ofwdisk = {
    "block",
    DEVT_DISK,
    ofwd_init,
    ofwd_strategy,
    ofwd_open,
    ofwd_close,
    ofwd_ioctl,
    ofwd_print
};

/*
 * We're not guaranteed to be able to open a device more than once and there
 * is no OFW standard method to determine whether a device is already opened.
 * Opening a device multiple times simultaneously happens to work with most
 * OFW block device drivers but triggers a trap with at least the driver for
 * the on-board controllers of Sun Fire V100 and Ultra 1.  Upper layers and MI
 * code expect to be able to open a device more than once however.  Given that
 * different partitions of the same device might be opened at the same time as
 * done by ZFS, we can't generally just keep track of the opened devices and
 * reuse the instance handle when asked to open an already opened device.  So
 * the best we can do is to cache the lastly used device path and close and
 * open devices in ofwd_strategy() as needed.
 */
static struct ofw_devdesc *kdp;

static int
ofwd_init(void)
{

    return (0);
}

static int
ofwd_strategy(void *devdata, int flag __unused, daddr_t dblk, size_t size,
    char *buf, size_t *rsize)
{
    struct ofw_devdesc *dp = (struct ofw_devdesc *)devdata;
    daddr_t pos;
    int n;

    if (dp != kdp) {
        if (kdp != NULL) {
#if !defined(__powerpc__)
            OF_close(kdp->d_handle);
#endif
            kdp = NULL;
        }
        if ((dp->d_handle = OF_open(dp->d_path)) == -1)
            return (ENOENT);
        kdp = dp;
    }

    pos = dblk * 512;
    do {
        if (OF_seek(dp->d_handle, pos) < 0)
            return (EIO);
        n = OF_read(dp->d_handle, buf, size);
        if (n < 0 && n != -2)
            return (EIO);
    } while (n == -2);
    *rsize = size;
    return (0);
}

static int
ofwd_open(struct open_file *f, ...)
{
    struct ofw_devdesc *dp;
    va_list vl;

    va_start(vl, f);
    dp = va_arg(vl, struct ofw_devdesc *);
    va_end(vl);

    if (dp != kdp) {
        if (kdp != NULL) {
            OF_close(kdp->d_handle);
            kdp = NULL;
        }
        if ((dp->d_handle = OF_open(dp->d_path)) == -1) {
            printf("%s: Could not open %s\n", __func__,
                dp->d_path);
            return (ENOENT);
        }
        kdp = dp;
    }
    return (0);
}

static int
ofwd_close(struct open_file *f)
{
    struct ofw_devdesc *dev = f->f_devdata;

    if (dev == kdp) {
#if !defined(__powerpc__)
        OF_close(dev->d_handle);
#endif
        kdp = NULL;
    }
    return (0);
}

static int
ofwd_ioctl(struct open_file *f __unused, u_long cmd __unused,
    void *data __unused)
{

    return (EINVAL);
}

static void
ofwd_print(int verbose __unused)
{

}