kernel/os/fbio.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  23 /*        All Rights Reserved   */
  24
  25
  26 /*
  27  * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
  28  * Use is subject to license terms.
  29  */
  30
  31 #pragma ident   "%Z%%M% %I%     %E% SMI"
  32
  33 #include <sys/types.h>
  34 #include <sys/buf.h>
  35 #include <sys/cmn_err.h>
  36 #include <sys/conf.h>
  37 #include <sys/debug.h>
  38 #include <sys/errno.h>
  39 #include <sys/fbuf.h>
  40 #include <sys/kmem.h>
  41 #include <sys/param.h>
  42 #include <sys/sysmacros.h>
  43 #include <sys/vfs.h>
  44 #include <sys/cred.h>
  45 #include <sys/vnode.h>
  46 #include <vm/hat.h>
  47 #include <vm/as.h>
  48 #include <vm/seg.h>
  49 #include <vm/seg_kmem.h>
  50 #include <vm/seg_map.h>
  51 #include <vm/seg_kpm.h>
  52
  53
  54 /*
  55  * Pseudo-bio routines which use a segmap mapping to address file data.
  56  */
  57
  58 /*
  59  * Return a pointer to locked kernel virtual address for
  60  * the given <vp, off> for len bytes.  It is not allowed to
  61  * have the offset cross a MAXBSIZE boundary over len bytes.
  62  */
  63 int
  64 fbread(vnode_t *vp, offset_t off, uint_t len, enum seg_rw rw,
  65         struct fbuf **fbpp)
  66 {
  67         caddr_t addr;
  68         ulong_t o;
  69         struct fbuf *fbp;
  70         faultcode_t err;
  71         caddr_t raddr;
  72         uint_t  rsize;
  73         uintptr_t pgoff = PAGEOFFSET;
  74
  75         o = (ulong_t)(off & (offset_t)MAXBOFFSET);
  76         if (o + len > MAXBSIZE)
  77                 cmn_err(CE_PANIC, "fbread");
  78
  79         if (segmap_kpm) {
  80                 addr = segmap_getmapflt(segkmap, vp, off & (offset_t)MAXBMASK,
  81                                         MAXBSIZE, SM_LOCKPROTO, rw);
  82         } else {
  83                 addr = segmap_getmapflt(segkmap, vp,
  84                                 off & (offset_t)MAXBMASK, MAXBSIZE, 0, rw);
  85         }
  86
  87         raddr = (caddr_t)((uintptr_t)(addr + o) & ~pgoff);
  88         rsize = (((uintptr_t)(addr + o) + len + pgoff) & ~pgoff) -
  89             (uintptr_t)raddr;
  90
  91         err = segmap_fault(kas.a_hat, segkmap, raddr, rsize, F_SOFTLOCK, rw);
  92         if (err) {
  93                 (void) segmap_release(segkmap, addr, 0);
  94                 if (FC_CODE(err) == FC_OBJERR)
  95                         return (FC_ERRNO(err));
  96                 else
  97                         return (EIO);
  98         }
  99
 100         *fbpp = fbp = kmem_alloc(sizeof (struct fbuf), KM_SLEEP);
 101         fbp->fb_addr = addr + o;
 102         fbp->fb_count = len;
 103         return (0);
 104 }
 105
 106 /*
 107  * Similar to fbread() but we call segmap_pagecreate instead of using
 108  * segmap_fault for SOFTLOCK to create the pages without using fop_getpage
 109  * and then we zero up to the length rounded to a page boundary.
 110  * XXX - this won't work right when bsize < PAGESIZE!!!
 111  */
 112 void
 113 fbzero(vnode_t *vp, offset_t off, uint_t len, struct fbuf **fbpp)
 114 {
 115         caddr_t addr;
 116         ulong_t o, zlen;
 117         struct fbuf *fbp;
 118
 119         o = (ulong_t)(off & MAXBOFFSET);
 120         if (o + len > MAXBSIZE)
 121                 cmn_err(CE_PANIC, "fbzero: Bad offset/length");
 122
 123         if (segmap_kpm) {
 124                 addr = segmap_getmapflt(segkmap, vp, off & (offset_t)MAXBMASK,
 125                                 MAXBSIZE, SM_PAGECREATE, S_WRITE) + o;
 126         } else {
 127                 addr = segmap_getmap(segkmap, vp, off & (offset_t)MAXBMASK) + o;
 128         }
 129
 130         *fbpp = fbp = kmem_alloc(sizeof (struct fbuf), KM_SLEEP);
 131         fbp->fb_addr = addr;
 132         fbp->fb_count = len;
 133
 134         (void) segmap_pagecreate(segkmap, addr, len, 1);
 135
 136         /*
 137          * Now we zero all the memory in the mapping we are interested in.
 138          */
 139         zlen = (caddr_t)ptob(btopr((uintptr_t)(len + addr))) - addr;
 140         if (zlen < len || (o + zlen > MAXBSIZE))
 141                 cmn_err(CE_PANIC, "fbzero: Bad zlen");
 142         bzero(addr, zlen);
 143 }
 144
 145 /*
 146  * FBCOMMON() is the common code for fbrelse, fbwrite and variants thereof:
 147  *
 148  * fbrelse()    release fbp
 149  * fbwrite()    direct write
 150  * fbdwrite()   delayed write
 151  */
 152 #define FBCOMMON(fbp, rw, flags, howtoreturn) \
 153 { \
 154         caddr_t addr; \
 155         size_t size; \
 156         uintptr_t pgoff = PAGEOFFSET; \
 157         addr = (caddr_t)((uintptr_t)fbp->fb_addr & ~pgoff); \
 158         size = ((fbp->fb_addr - addr) + fbp->fb_count + pgoff) & ~pgoff; \
 159         (void) segmap_fault(kas.a_hat, segkmap, addr, size, F_SOFTUNLOCK, rw); \
 160         addr = (caddr_t)((uintptr_t)fbp->fb_addr & MAXBMASK); \
 161         kmem_free(fbp, sizeof (struct fbuf)); \
 162         howtoreturn(segmap_release(segkmap, addr, flags)); \
 163 }
 164
 165 void
 166 fbrelse(struct fbuf *fbp, enum seg_rw rw)
 167 {
 168         FBCOMMON(fbp, rw, 0, (void))
 169 }
 170
 171 int
 172 fbwrite(struct fbuf *fbp)
 173 {
 174         FBCOMMON(fbp, S_WRITE, SM_WRITE, return)
 175 }
 176
 177 int
 178 fbdwrite(struct fbuf *fbp)
 179 {
 180         FBCOMMON(fbp, S_WRITE, 0, return)
 181 }
 182
 183 /*
 184  * Perform a synchronous indirect write of the given block number
 185  * on the given device, using the given fbuf.  Upon return the fbp
 186  * is invalid.
 187  */
 188 int
 189 fbiwrite(struct fbuf *fbp, vnode_t *devvp, daddr_t bn, int bsize)
 190 {
 191         struct buf *bp;
 192         int error, fberror;
 193
 194         /*
 195          * Allocate a temp bp using pageio_setup, but then use it
 196          * for physio to the area mapped by fbuf which is currently
 197          * all locked down in place.
 198          *
 199          * XXX - need to have a generalized bp header facility
 200          * which we build up pageio_setup on top of.  Other places
 201          * (like here and in device drivers for the raw I/O case)
 202          * could then use these new facilities in a more straight
 203          * forward fashion instead of playing all these games.
 204          */
 205         bp = pageio_setup(NULL, fbp->fb_count, devvp, B_WRITE);
 206         bp->b_flags &= ~B_PAGEIO;               /* XXX */
 207         bp->b_un.b_addr = fbp->fb_addr;
 208
 209         bp->b_blkno = bn * btod(bsize);
 210         bp->b_dev = cmpdev(devvp->v_rdev);      /* store in old dev format */
 211         bp->b_edev = devvp->v_rdev;
 212         bp->b_proc = NULL;                      /* i.e. the kernel */
 213
 214         (void) bdev_strategy(bp);
 215         error = biowait(bp);
 216         pageio_done(bp);
 217
 218         /*CSTYLED*/
 219         FBCOMMON(fbp, S_OTHER, 0, fberror = )
 220
 221         return (error ? error : fberror);
 222 }