| | 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 1.6 2004/02/09 21:51:28 hmp 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 | static void |
| | 35 | physwakeup(struct buf *bp) |
| | 36 | { |
| | 37 | wakeup((caddr_t) bp); |
| | 38 | } |
| | 39 | |
| | 40 | int |
| | 41 | physio(dev_t dev, struct uio *uio, int ioflag) |
| | 42 | { |
| | 43 | int i; |
| | 44 | int error; |
| | 45 | int spl; |
| | 46 | int chk_blockno; |
| | 47 | caddr_t sa; |
| | 48 | off_t blockno; |
| | 49 | u_int iolen; |
| | 50 | struct buf *bp; |
| | 51 | |
| | 52 | /* |
| | 53 | * NOTE: we no longer have to PHOLD() the process, because the |
| | 54 | * kernel stack / uarea cannot be swapped, and when it can be in |
| | 55 | * the future it will only happen if the process is sleeping on |
| | 56 | * a particular address. |
| | 57 | */ |
| | 58 | bp = getpbuf(NULL); |
| | 59 | sa = bp->b_data; |
| | 60 | error = 0; |
| | 61 | |
| | 62 | /* XXX: sanity check */ |
| | 63 | if(dev->si_iosize_max < PAGE_SIZE) { |
| | 64 | printf("WARNING: %s si_iosize_max=%d, using DFLTPHYS.\n", |
| | 65 | devtoname(dev), dev->si_iosize_max); |
| | 66 | dev->si_iosize_max = DFLTPHYS; |
| | 67 | } |
| | 68 | |
| | 69 | /* Don't check block number overflow for D_MEM */ |
| | 70 | if ((devsw(dev)->d_flags & D_TYPEMASK) == D_MEM) |
| | 71 | chk_blockno = 0; |
| | 72 | else |
| | 73 | chk_blockno = 1; |
| | 74 | |
| | 75 | for (i = 0; i < uio->uio_iovcnt; i++) { |
| | 76 | while (uio->uio_iov[i].iov_len) { |
| | 77 | if (uio->uio_rw == UIO_READ) |
| | 78 | bp->b_flags = B_PHYS | B_CALL | B_READ; |
| | 79 | else |
| | 80 | bp->b_flags = B_PHYS | B_CALL | B_WRITE; |
| | 81 | bp->b_dev = dev; |
| | 82 | bp->b_iodone = physwakeup; |
| | 83 | bp->b_data = uio->uio_iov[i].iov_base; |
| | 84 | bp->b_bcount = uio->uio_iov[i].iov_len; |
| | 85 | bp->b_offset = uio->uio_offset; |
| | 86 | bp->b_saveaddr = sa; |
| | 87 | |
| | 88 | /* Don't exceed drivers iosize limit */ |
| | 89 | if (bp->b_bcount > dev->si_iosize_max) |
| | 90 | bp->b_bcount = dev->si_iosize_max; |
| | 91 | |
| | 92 | /* |
| | 93 | * Make sure the pbuf can map the request |
| | 94 | * XXX: The pbuf has kvasize = MAXPHYS so a request |
| | 95 | * XXX: larger than MAXPHYS - PAGE_SIZE must be |
| | 96 | * XXX: page aligned or it will be fragmented. |
| | 97 | */ |
| | 98 | iolen = ((vm_offset_t) bp->b_data) & PAGE_MASK; |
| | 99 | if ((bp->b_bcount + iolen) > bp->b_kvasize) { |
| | 100 | bp->b_bcount = bp->b_kvasize; |
| | 101 | if (iolen != 0) |
| | 102 | bp->b_bcount -= PAGE_SIZE; |
| | 103 | } |
| | 104 | bp->b_bufsize = bp->b_bcount; |
| | 105 | |
| | 106 | blockno = bp->b_offset >> DEV_BSHIFT; |
| | 107 | if (chk_blockno && (daddr_t)blockno != blockno) { |
| | 108 | error = EINVAL; /* blockno overflow */ |
| | 109 | goto doerror; |
| | 110 | } |
| | 111 | bp->b_blkno = blockno; |
| | 112 | |
| | 113 | if (uio->uio_segflg == UIO_USERSPACE) |
| | 114 | if (vmapbuf(bp) < 0) { |
| | 115 | error = EFAULT; |
| | 116 | goto doerror; |
| | 117 | } |
| | 118 | |
| | 119 | BUF_STRATEGY(bp, 0); |
| | 120 | spl = splbio(); |
| | 121 | while ((bp->b_flags & B_DONE) == 0) |
| | 122 | tsleep((caddr_t)bp, 0, "physstr", 0); |
| | 123 | splx(spl); |
| | 124 | |
| | 125 | if (uio->uio_segflg == UIO_USERSPACE) |
| | 126 | vunmapbuf(bp); |
| | 127 | iolen = bp->b_bcount - bp->b_resid; |
| | 128 | if (iolen == 0 && !(bp->b_flags & B_ERROR)) |
| | 129 | goto doerror; /* EOF */ |
| | 130 | uio->uio_iov[i].iov_len -= iolen; |
| | 131 | uio->uio_iov[i].iov_base += iolen; |
| | 132 | uio->uio_resid -= iolen; |
| | 133 | uio->uio_offset += iolen; |
| | 134 | if( bp->b_flags & B_ERROR) { |
| | 135 | error = bp->b_error; |
| | 136 | goto doerror; |
| | 137 | } |
| | 138 | } |
| | 139 | } |
| | 140 | doerror: |
| | 141 | relpbuf(bp, NULL); |
| | 142 | return (error); |
| | 143 | } |
projects / dragonfly.git / blame_incremental