fbio.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* Copyright 2003 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <sys/types.h>
#include <sys/buf.h>
#include <sys/cmn_err.h>
#include <sys/conf.h>
#include <sys/debug.h>
#include <sys/errno.h>
#include <sys/fbuf.h>
#include <sys/kmem.h>
#include <sys/param.h>
#include <sys/sysmacros.h>
#include <sys/vfs.h>
#include <sys/cred.h>
#include <sys/vnode.h>
#include <vm/hat.h>
#include <vm/as.h>
#include <vm/seg.h>
#include <vm/seg_kmem.h>
#include <vm/seg_map.h>
#include <vm/seg_kpm.h>
/*
* Pseudo-bio routines which use a segmap mapping to address file data.
*/
/*
* Return a pointer to locked kernel virtual address for
* the given <vp, off> for len bytes. It is not allowed to
* have the offset cross a MAXBSIZE boundary over len bytes.
*/
int
fbread(vnode_t *vp, offset_t off, uint_t len, enum seg_rw rw,
struct fbuf **fbpp)
{
caddr_t addr;
ulong_t o;
struct fbuf *fbp;
faultcode_t err;
caddr_t raddr;
uint_t rsize;
uintptr_t pgoff = PAGEOFFSET;
o = (ulong_t)(off & (offset_t)MAXBOFFSET);
if (o + len > MAXBSIZE)
cmn_err(CE_PANIC, "fbread");
if (segmap_kpm) {
addr = segmap_getmapflt(segkmap, vp, off & (offset_t)MAXBMASK,
MAXBSIZE, SM_LOCKPROTO, rw);
} else {
addr = segmap_getmapflt(segkmap, vp,
off & (offset_t)MAXBMASK, MAXBSIZE, 0, rw);
}
raddr = (caddr_t)((uintptr_t)(addr + o) & ~pgoff);
rsize = (((uintptr_t)(addr + o) + len + pgoff) & ~pgoff) -
(uintptr_t)raddr;
err = segmap_fault(kas.a_hat, segkmap, raddr, rsize, F_SOFTLOCK, rw);
if (err) {
(void) segmap_release(segkmap, addr, 0);
if (FC_CODE(err) == FC_OBJERR)
return (FC_ERRNO(err));
else
return (EIO);
}
*fbpp = fbp = kmem_alloc(sizeof (struct fbuf), KM_SLEEP);
fbp->fb_addr = addr + o;
fbp->fb_count = len;
return (0);
}
/*
* Similar to fbread() but we call segmap_pagecreate instead of using
* segmap_fault for SOFTLOCK to create the pages without using VOP_GETPAGE
* and then we zero up to the length rounded to a page boundary.
* XXX - this won't work right when bsize < PAGESIZE!!!
*/
void
fbzero(vnode_t *vp, offset_t off, uint_t len, struct fbuf **fbpp)
{
caddr_t addr;
ulong_t o, zlen;
struct fbuf *fbp;
o = (ulong_t)(off & MAXBOFFSET);
if (o + len > MAXBSIZE)
cmn_err(CE_PANIC, "fbzero: Bad offset/length");
if (segmap_kpm) {
addr = segmap_getmapflt(segkmap, vp, off & (offset_t)MAXBMASK,
MAXBSIZE, SM_PAGECREATE, S_WRITE) + o;
} else {
addr = segmap_getmap(segkmap, vp, off & (offset_t)MAXBMASK) + o;
}
*fbpp = fbp = kmem_alloc(sizeof (struct fbuf), KM_SLEEP);
fbp->fb_addr = addr;
fbp->fb_count = len;
(void) segmap_pagecreate(segkmap, addr, len, 1);
/*
* Now we zero all the memory in the mapping we are interested in.
*/
zlen = (caddr_t)ptob(btopr((uintptr_t)(len + addr))) - addr;
if (zlen < len || (o + zlen > MAXBSIZE))
cmn_err(CE_PANIC, "fbzero: Bad zlen");
bzero(addr, zlen);
}
/*
* FBCOMMON() is the common code for fbrelse, fbwrite and variants thereof:
*
* fbrelse() release fbp
* fbwrite() direct write
* fbdwrite() delayed write
*/
#define FBCOMMON(fbp, rw, flags, howtoreturn) \
{ \
caddr_t addr; \
size_t size; \
uintptr_t pgoff = PAGEOFFSET; \
addr = (caddr_t)((uintptr_t)fbp->fb_addr & ~pgoff); \
size = ((fbp->fb_addr - addr) + fbp->fb_count + pgoff) & ~pgoff; \
(void) segmap_fault(kas.a_hat, segkmap, addr, size, F_SOFTUNLOCK, rw); \
addr = (caddr_t)((uintptr_t)fbp->fb_addr & MAXBMASK); \
kmem_free(fbp, sizeof (struct fbuf)); \
howtoreturn(segmap_release(segkmap, addr, flags)); \
}
void
fbrelse(struct fbuf *fbp, enum seg_rw rw)
{
FBCOMMON(fbp, rw, 0, (void))
}
int
fbwrite(struct fbuf *fbp)
{
FBCOMMON(fbp, S_WRITE, SM_WRITE, return)
}
int
fbdwrite(struct fbuf *fbp)
{
FBCOMMON(fbp, S_WRITE, 0, return)
}
/*
* Perform a synchronous indirect write of the given block number
* on the given device, using the given fbuf. Upon return the fbp
* is invalid.
*/
int
fbiwrite(struct fbuf *fbp, vnode_t *devvp, daddr_t bn, int bsize)
{
struct buf *bp;
int error, fberror;
/*
* Allocate a temp bp using pageio_setup, but then use it
* for physio to the area mapped by fbuf which is currently
* all locked down in place.
*
* XXX - need to have a generalized bp header facility
* which we build up pageio_setup on top of. Other places
* (like here and in device drivers for the raw I/O case)
* could then use these new facilities in a more straight
* forward fashion instead of playing all these games.
*/
bp = pageio_setup((struct page *)NULL, fbp->fb_count, devvp, B_WRITE);
bp->b_flags &= ~B_PAGEIO; /* XXX */
bp->b_un.b_addr = fbp->fb_addr;
bp->b_blkno = bn * btod(bsize);
bp->b_dev = cmpdev(devvp->v_rdev); /* store in old dev format */
bp->b_edev = devvp->v_rdev;
bp->b_proc = NULL; /* i.e. the kernel */
(void) bdev_strategy(bp);
error = biowait(bp);
pageio_done(bp);
/*CSTYLED*/
FBCOMMON(fbp, S_OTHER, 0, fberror = )
return (error ? error : fberror);
}