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 1.10 2005/06/06 15:02:28 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 31 #include <vm/vm.h> 32 #include <vm/vm_extern.h> 33 34 #include <machine/physio_proc.h> 35 36 /* I have no idea what this is used for */ 37 struct physio_proc_head physio_proc_freet, physio_proc_busyt; 38 39 static void 40 physwakeup(struct buf *bp) 41 { 42 wakeup((caddr_t) bp); 43 } 44 45 int 46 physio(dev_t dev, struct uio *uio, int ioflag) 47 { 48 int i; 49 int error; 50 int chk_blockno; 51 caddr_t sa; 52 off_t blockno; 53 u_int iolen; 54 struct buf *bp; 55 56 /* 57 * NOTE: we no longer have to PHOLD() the process, because the 58 * kernel stack / uarea cannot be swapped, and when it can be in 59 * the future it will only happen if the process is sleeping on 60 * a particular address. 61 */ 62 bp = getpbuf(NULL); 63 sa = bp->b_data; 64 error = 0; 65 66 /* XXX: sanity check */ 67 if(dev->si_iosize_max < PAGE_SIZE) { 68 printf("WARNING: %s si_iosize_max=%d, using DFLTPHYS.\n", 69 devtoname(dev), dev->si_iosize_max); 70 dev->si_iosize_max = DFLTPHYS; 71 } 72 73 /* Don't check block number overflow for D_MEM */ 74 if ((dev_dflags(dev) & D_TYPEMASK) == D_MEM) 75 chk_blockno = 0; 76 else 77 chk_blockno = 1; 78 79 for (i = 0; i < uio->uio_iovcnt; i++) { 80 while (uio->uio_iov[i].iov_len) { 81 if (uio->uio_rw == UIO_READ) 82 bp->b_flags = B_PHYS | B_CALL | B_READ; 83 else 84 bp->b_flags = B_PHYS | B_CALL | B_WRITE; 85 bp->b_dev = dev; 86 bp->b_iodone = physwakeup; 87 bp->b_data = uio->uio_iov[i].iov_base; 88 bp->b_bcount = uio->uio_iov[i].iov_len; 89 bp->b_offset = uio->uio_offset; 90 bp->b_saveaddr = sa; 91 92 /* Don't exceed drivers iosize limit */ 93 if (bp->b_bcount > dev->si_iosize_max) 94 bp->b_bcount = dev->si_iosize_max; 95 96 /* 97 * Make sure the pbuf can map the request 98 * XXX: The pbuf has kvasize = MAXPHYS so a request 99 * XXX: larger than MAXPHYS - PAGE_SIZE must be 100 * XXX: page aligned or it will be fragmented. 101 */ 102 iolen = ((vm_offset_t) bp->b_data) & PAGE_MASK; 103 if ((bp->b_bcount + iolen) > bp->b_kvasize) { 104 bp->b_bcount = bp->b_kvasize; 105 if (iolen != 0) 106 bp->b_bcount -= PAGE_SIZE; 107 } 108 bp->b_bufsize = bp->b_bcount; 109 110 blockno = bp->b_offset >> DEV_BSHIFT; 111 if (chk_blockno && (daddr_t)blockno != blockno) { 112 error = EINVAL; /* blockno overflow */ 113 goto doerror; 114 } 115 bp->b_blkno = blockno; 116 117 if (uio->uio_segflg == UIO_USERSPACE) 118 if (vmapbuf(bp) < 0) { 119 error = EFAULT; 120 goto doerror; 121 } 122 123 BUF_STRATEGY(bp, 0); 124 crit_enter(); 125 while ((bp->b_flags & B_DONE) == 0) 126 tsleep((caddr_t)bp, 0, "physstr", 0); 127 crit_exit(); 128 129 if (uio->uio_segflg == UIO_USERSPACE) 130 vunmapbuf(bp); 131 iolen = bp->b_bcount - bp->b_resid; 132 if (iolen == 0 && !(bp->b_flags & B_ERROR)) 133 goto doerror; /* EOF */ 134 uio->uio_iov[i].iov_len -= iolen; 135 uio->uio_iov[i].iov_base += iolen; 136 uio->uio_resid -= iolen; 137 uio->uio_offset += iolen; 138 if( bp->b_flags & B_ERROR) { 139 error = bp->b_error; 140 goto doerror; 141 } 142 } 143 } 144 doerror: 145 bp->b_data = sa; 146 relpbuf(bp, NULL); 147 return (error); 148 } 149