freebsd-dev/sys/boot/efi/libefi/efipart.c

/*-
 * Copyright (c) 2010 Marcel Moolenaar
 * 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 THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR CONTRIBUTORS 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("$FreeBSD$");

#include <sys/param.h>
#include <sys/time.h>
#include <stddef.h>
#include <stdarg.h>

#include <bootstrap.h>

#include <efi.h>
#include <efilib.h>
#include <efiprot.h>

static EFI_GUID blkio_guid = BLOCK_IO_PROTOCOL;
static EFI_GUID devpath_guid = DEVICE_PATH_PROTOCOL;

static int efipart_init(void);
static int efipart_strategy(void *, int, daddr_t, size_t, char *, size_t *);
static int efipart_open(struct open_file *, ...);
static int efipart_close(struct open_file *);
static void efipart_print(int);

struct devsw efipart_dev = {
	.dv_name = "part",
	.dv_type = DEVT_DISK,
	.dv_init = efipart_init,
	.dv_strategy = efipart_strategy,
	.dv_open = efipart_open,
	.dv_close = efipart_close,
	.dv_ioctl = noioctl,
	.dv_print = efipart_print,
	.dv_cleanup = NULL
};

static int
efipart_init(void) 
{
	EFI_BLOCK_IO *blkio;
	EFI_DEVICE_PATH *devpath, *node;
	EFI_HANDLE *hin, *hout, *aliases, handle;
	EFI_STATUS status;
	UINTN sz;
	CHAR16 *path;
	u_int n, nin, nout;
	int err;

	sz = 0;
	hin = NULL;
	status = BS->LocateHandle(ByProtocol, &blkio_guid, 0, &sz, 0);
	if (status == EFI_BUFFER_TOO_SMALL) {
		hin = (EFI_HANDLE *)malloc(sz * 3);
		status = BS->LocateHandle(ByProtocol, &blkio_guid, 0, &sz,
		    hin);
		if (EFI_ERROR(status))
			free(hin);
	}
	if (EFI_ERROR(status))
		return (efi_status_to_errno(status));

	/* Filter handles to only include FreeBSD partitions. */
	nin = sz / sizeof(EFI_HANDLE);
	hout = hin + nin;
	aliases = hout + nin;
	nout = 0;

	bzero(aliases, nin * sizeof(EFI_HANDLE));

	for (n = 0; n < nin; n++) {
		status = BS->HandleProtocol(hin[n], &devpath_guid, &devpath);
		if (EFI_ERROR(status)) {
			continue;
		}
		node = devpath;
		while (!IsDevicePathEnd(NextDevicePathNode(node)))
			node = NextDevicePathNode(node);
		status = BS->HandleProtocol(hin[n], &blkio_guid, &blkio);
		if (EFI_ERROR(status))
			continue;
		if (!blkio->Media->LogicalPartition)
			continue;

		/*
		 * If we come across a logical partition of subtype CDROM
		 * it doesn't refer to the CD filesystem itself, but rather
		 * to any usable El Torito boot image on it. In this case
		 * we try to find the parent device and add that instead as
		 * that will be the CD filesystem.
		 */
		if (DevicePathType(node) == MEDIA_DEVICE_PATH &&
		    DevicePathSubType(node) == MEDIA_CDROM_DP) {
			node->Type = END_DEVICE_PATH_TYPE;
			node->SubType = END_ENTIRE_DEVICE_PATH_SUBTYPE;
			status = BS->LocateDevicePath(&blkio_guid, &devpath,
			    &handle);
			if (EFI_ERROR(status))
				continue;
			hout[nout] = handle;
			aliases[nout] = hin[n];
		} else
			hout[nout] = hin[n];
		nout++;
	}

	err = efi_register_handles(&efipart_dev, hout, aliases, nout);
	free(hin);
	return (err);
}

static void
efipart_print(int verbose)
{
	char line[80];
	EFI_BLOCK_IO *blkio;
	EFI_HANDLE h;
	EFI_STATUS status;
	u_int unit;

	for (unit = 0, h = efi_find_handle(&efipart_dev, 0);
	    h != NULL; h = efi_find_handle(&efipart_dev, ++unit)) {
		sprintf(line, "    %s%d:", efipart_dev.dv_name, unit);
		pager_output(line);

		status = BS->HandleProtocol(h, &blkio_guid, &blkio);
		if (!EFI_ERROR(status)) {
			sprintf(line, "    %llu blocks",
			    (unsigned long long)(blkio->Media->LastBlock + 1));
			pager_output(line);
			if (blkio->Media->RemovableMedia)
				pager_output(" (removable)");
		}
		pager_output("\n");
	}
}

static int 
efipart_open(struct open_file *f, ...)
{
	va_list args;
	struct devdesc *dev;
	EFI_BLOCK_IO *blkio;
	EFI_HANDLE h;
	EFI_STATUS status;

	va_start(args, f);
	dev = va_arg(args, struct devdesc*);
	va_end(args);

	h = efi_find_handle(&efipart_dev, dev->d_unit);
	if (h == NULL)
		return (EINVAL);

	status = BS->HandleProtocol(h, &blkio_guid, &blkio);
	if (EFI_ERROR(status))
		return (efi_status_to_errno(status));

	if (!blkio->Media->MediaPresent)
		return (EAGAIN);

	dev->d_opendata = blkio;
	return (0);
}

static int 
efipart_close(struct open_file *f)
{
	struct devdesc *dev;

	dev = (struct devdesc *)(f->f_devdata);
	if (dev->d_opendata == NULL)
		return (EINVAL);

	dev->d_opendata = NULL;
	return (0);
}

/*
 * efipart_readwrite()
 * Internal equivalent of efipart_strategy(), which operates on the
 * media-native block size. This function expects all I/O requests
 * to be within the media size and returns an error if such is not
 * the case.
 */
static int
efipart_readwrite(EFI_BLOCK_IO *blkio, int rw, daddr_t blk, daddr_t nblks,
    char *buf)
{
	EFI_STATUS status;

	if (blkio == NULL)
		return (ENXIO);
	if (blk < 0 || blk > blkio->Media->LastBlock)
		return (EIO);
	if ((blk + nblks - 1) > blkio->Media->LastBlock)
		return (EIO);

	switch (rw) {
	case F_READ:
		status = blkio->ReadBlocks(blkio, blkio->Media->MediaId, blk,
		    nblks * blkio->Media->BlockSize, buf);
		break;
	case F_WRITE:
		if (blkio->Media->ReadOnly)
			return (EROFS);
		status = blkio->WriteBlocks(blkio, blkio->Media->MediaId, blk,
		    nblks * blkio->Media->BlockSize, buf);
		break;
	default:
		return (ENOSYS);
	}

	if (EFI_ERROR(status))
		printf("%s: rw=%d, status=%lu\n", __func__, rw, (u_long)status);
	return (efi_status_to_errno(status));
}

static int 
efipart_strategy(void *devdata, int rw, daddr_t blk, size_t size, char *buf,
    size_t *rsize)
{
	struct devdesc *dev = (struct devdesc *)devdata;
	EFI_BLOCK_IO *blkio;
	off_t off;
	char *blkbuf;
	size_t blkoff, blksz;
	int error;

	if (dev == NULL || blk < 0)
		return (EINVAL);

	blkio = dev->d_opendata;
	if (blkio == NULL)
		return (ENXIO);

	if (size == 0 || (size % 512) != 0)
		return (EIO);

	if (rsize != NULL)
		*rsize = size;

	if (blkio->Media->BlockSize == 512)
		return (efipart_readwrite(blkio, rw, blk, size / 512, buf));

	/*
	 * The block size of the media is not 512B per sector.
	 */
	blkbuf = malloc(blkio->Media->BlockSize);
	if (blkbuf == NULL)
		return (ENOMEM);

	error = 0;
	off = blk * 512;
	blk = off / blkio->Media->BlockSize;
	blkoff = off % blkio->Media->BlockSize;
	blksz = blkio->Media->BlockSize - blkoff;
	while (size > 0) {
		error = efipart_readwrite(blkio, rw, blk, 1, blkbuf);
		if (error)
			break;
		if (size < blksz)
			blksz = size;
		bcopy(blkbuf + blkoff, buf, blksz);
		buf += blksz;
		size -= blksz;
		blk++;
		blkoff = 0;
		blksz = blkio->Media->BlockSize;
	}

	free(blkbuf);
	return (error);
}