1 /* 2 * Copyright (c) 1994 John S. Dyson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice immediately at the beginning of the file, without modification, 10 * this list of conditions, and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Absolutely no warranty of function or purpose is made by the author 15 * John S. Dyson. 16 * 4. Modifications may be freely made to this file if the above conditions 17 * are met. 18 * 19 * $FreeBSD: src/sys/kern/kern_physio.c,v 1.46.2.4 2003/11/14 09:51:47 simokawa Exp $ 20 * $DragonFly: src/sys/kern/kern_physio.c,v 1.13 2005/11/19 17:58:21 dillon Exp $ 21 */ 22 23 #include <sys/param.h> 24 #include <sys/systm.h> 25 #include <sys/buf.h> 26 #include <sys/conf.h> 27 #include <sys/proc.h> 28 #include <sys/uio.h> 29 #include <sys/device.h> 30 #include <sys/thread2.h> 31 32 #include <vm/vm.h> 33 #include <vm/vm_extern.h> 34 35 static void 36 physwakeup(struct buf *bp) 37 { 38 wakeup((caddr_t) bp); 39 } 40 41 int 42 physio(dev_t dev, struct uio *uio, int ioflag) 43 { 44 int i; 45 int error; 46 int chk_blockno; 47 caddr_t sa; 48 off_t blockno; 49 u_int iolen; 50 struct buf *bp; 51 52 bp = getpbuf(NULL); 53 sa = bp->b_data; 54 error = 0; 55 56 /* XXX: sanity check */ 57 if(dev->si_iosize_max < PAGE_SIZE) { 58 printf("WARNING: %s si_iosize_max=%d, using DFLTPHYS.\n", 59 devtoname(dev), dev->si_iosize_max); 60 dev->si_iosize_max = DFLTPHYS; 61 } 62 63 /* Don't check block number overflow for D_MEM */ 64 if ((dev_dflags(dev) & D_TYPEMASK) == D_MEM) 65 chk_blockno = 0; 66 else 67 chk_blockno = 1; 68 69 for (i = 0; i < uio->uio_iovcnt; i++) { 70 while (uio->uio_iov[i].iov_len) { 71 if (uio->uio_rw == UIO_READ) 72 bp->b_flags = B_PHYS | B_READ; 73 else 74 bp->b_flags = B_PHYS | B_WRITE; 75 bp->b_dev = dev; 76 bp->b_iodone = physwakeup; 77 bp->b_data = uio->uio_iov[i].iov_base; 78 bp->b_bcount = uio->uio_iov[i].iov_len; 79 bp->b_offset = uio->uio_offset; 80 bp->b_saveaddr = sa; 81 82 /* Don't exceed drivers iosize limit */ 83 if (bp->b_bcount > dev->si_iosize_max) 84 bp->b_bcount = dev->si_iosize_max; 85 86 /* 87 * Make sure the pbuf can map the request 88 * XXX: The pbuf has kvasize = MAXPHYS so a request 89 * XXX: larger than MAXPHYS - PAGE_SIZE must be 90 * XXX: page aligned or it will be fragmented. 91 */ 92 iolen = ((vm_offset_t) bp->b_data) & PAGE_MASK; 93 if ((bp->b_bcount + iolen) > bp->b_kvasize) { 94 bp->b_bcount = bp->b_kvasize; 95 if (iolen != 0) 96 bp->b_bcount -= PAGE_SIZE; 97 } 98 bp->b_bufsize = bp->b_bcount; 99 100 blockno = bp->b_offset >> DEV_BSHIFT; 101 if (chk_blockno && (daddr_t)blockno != blockno) { 102 error = EINVAL; /* blockno overflow */ 103 goto doerror; 104 } 105 bp->b_blkno = blockno; 106 107 if (uio->uio_segflg == UIO_USERSPACE) 108 if (vmapbuf(bp) < 0) { 109 error = EFAULT; 110 goto doerror; 111 } 112 113 BUF_STRATEGY(bp, 0); 114 crit_enter(); 115 while ((bp->b_flags & B_DONE) == 0) 116 tsleep((caddr_t)bp, 0, "physstr", 0); 117 crit_exit(); 118 119 if (uio->uio_segflg == UIO_USERSPACE) 120 vunmapbuf(bp); 121 iolen = bp->b_bcount - bp->b_resid; 122 if (iolen == 0 && !(bp->b_flags & B_ERROR)) 123 goto doerror; /* EOF */ 124 uio->uio_iov[i].iov_len -= iolen; 125 uio->uio_iov[i].iov_base += iolen; 126 uio->uio_resid -= iolen; 127 uio->uio_offset += iolen; 128 if( bp->b_flags & B_ERROR) { 129 error = bp->b_error; 130 goto doerror; 131 } 132 } 133 } 134 doerror: 135 bp->b_data = sa; 136 relpbuf(bp, NULL); 137 return (error); 138 } 139