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 1.24 2006/12/23 00:35:04 swildner 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 bio *bio) 37 { 38 bio->bio_buf->b_cmd = BUF_CMD_DONE; 39 wakeup(bio); 40 } 41 42 static int 43 physio(cdev_t dev, struct uio *uio, int ioflag) 44 { 45 int i; 46 int error; 47 int chk_blockno; 48 int saflags; 49 int iolen; 50 int bcount; 51 struct buf *bp; 52 53 bp = getpbuf(NULL); 54 saflags = bp->b_flags; 55 error = 0; 56 57 /* XXX: sanity check */ 58 if(dev->si_iosize_max < PAGE_SIZE) { 59 kprintf("WARNING: %s si_iosize_max=%d, using DFLTPHYS.\n", 60 devtoname(dev), dev->si_iosize_max); 61 dev->si_iosize_max = DFLTPHYS; 62 } 63 64 /* Don't check block number overflow for D_MEM */ 65 if ((dev_dflags(dev) & D_TYPEMASK) == D_MEM) 66 chk_blockno = 0; 67 else 68 chk_blockno = 1; 69 70 for (i = 0; i < uio->uio_iovcnt; i++) { 71 while (uio->uio_iov[i].iov_len) { 72 if (uio->uio_rw == UIO_READ) 73 bp->b_cmd = BUF_CMD_READ; 74 else 75 bp->b_cmd = BUF_CMD_WRITE; 76 bp->b_flags = saflags; 77 bcount = uio->uio_iov[i].iov_len; 78 79 reinitbufbio(bp); /* clear translation cache */ 80 bp->b_bio1.bio_offset = uio->uio_offset; 81 bp->b_bio1.bio_done = physwakeup; 82 83 /* Don't exceed drivers iosize limit */ 84 if (bcount > dev->si_iosize_max) 85 bcount = dev->si_iosize_max; 86 87 /* 88 * Make sure the pbuf can map the request 89 * XXX: The pbuf has kvasize = MAXPHYS so a request 90 * XXX: larger than MAXPHYS - PAGE_SIZE must be 91 * XXX: page aligned or it will be fragmented. 92 */ 93 iolen = ((vm_offset_t) uio->uio_iov[i].iov_base) & 94 PAGE_MASK; 95 if ((bcount + iolen) > bp->b_kvasize) { 96 bcount = bp->b_kvasize; 97 if (iolen != 0) 98 bcount -= PAGE_SIZE; 99 } 100 if (uio->uio_segflg == UIO_USERSPACE) { 101 if (vmapbuf(bp, uio->uio_iov[i].iov_base, bcount) < 0) { 102 error = EFAULT; 103 goto doerror; 104 } 105 } else { 106 bp->b_data = uio->uio_iov[i].iov_base; 107 bp->b_bcount = bcount; 108 } 109 dev_dstrategy(dev, &bp->b_bio1); 110 crit_enter(); 111 while (bp->b_cmd != BUF_CMD_DONE) 112 tsleep(&bp->b_bio1, 0, "physstr", 0); 113 crit_exit(); 114 115 if (uio->uio_segflg == UIO_USERSPACE) 116 vunmapbuf(bp); 117 iolen = bp->b_bcount - bp->b_resid; 118 if (iolen == 0 && !(bp->b_flags & B_ERROR)) 119 goto doerror; /* EOF */ 120 uio->uio_iov[i].iov_len -= iolen; 121 uio->uio_iov[i].iov_base += iolen; 122 uio->uio_resid -= iolen; 123 uio->uio_offset += iolen; 124 if( bp->b_flags & B_ERROR) { 125 error = bp->b_error; 126 goto doerror; 127 } 128 } 129 } 130 doerror: 131 relpbuf(bp, NULL); 132 return (error); 133 } 134 135 int 136 physread(struct dev_read_args *ap) 137 { 138 return(physio(ap->a_head.a_dev, ap->a_uio, ap->a_ioflag)); 139 } 140 141 int 142 physwrite(struct dev_write_args *ap) 143 { 144 return(physio(ap->a_head.a_dev, ap->a_uio, ap->a_ioflag)); 145 } 146 147