/* * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this * file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_LICENSE_HEADER_END@ */ /*- * Copyright (c) 1982, 1986, 1990, 1993 * The Regents of the University of California. All rights reserved. * (c) UNIX System Laboratories, Inc. * All or some portions of this file are derived from material licensed * to the University of California by American Telephone and Telegraph * Co. or Unix System Laboratories, Inc. and are reproduced herein with * the permission of UNIX System Laboratories, Inc. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * from: @(#)kern_physio.c 8.1 (Berkeley) 6/10/93 */ /* * HISTORY * 27-July-97 Umesh Vaishampayan (umeshv@apple.com) * Allow physio() to kernel space. */ #include <sys/param.h> #include <sys/systm.h> #include <sys/buf_internal.h> #include <sys/conf.h> #include <sys/proc_internal.h> #include <sys/uio_internal.h> int physio(strategy, bp, dev, flags, minphys, uio, blocksize) void (*strategy)(); buf_t bp; dev_t dev; int flags; u_int (*minphys)(); struct uio *uio; int blocksize; { struct proc *p = current_proc(); int error, i, nobuf, todo, iosize; #if LP64KERN int64_t done; #else int done; #endif error = 0; flags &= B_READ | B_WRITE; /* * [check user read/write access to the data buffer] * * Check each iov one by one. Note that we know if we're reading or * writing, so we ignore the uio's rw parameter. Also note that if * we're doing a read, that's a *write* to user-space. */ for (i = 0; i < uio->uio_iovcnt; i++) { if(UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) { if (!useracc(uio_iov_base_at(uio, i), uio_iov_len_at(uio, i), (flags == B_READ) ? B_WRITE : B_READ)) return (EFAULT); } } /* Make sure we have a buffer, creating one if necessary. */ if (nobuf = (bp == NULL)) { bp = buf_alloc((vnode_t)0); } /* [while the buffer is marked busy] */ while (((error = (int)buf_acquire(bp, 0, 0, 0)) == EAGAIN)); if (error) { if (nobuf) buf_free(bp); return (error); } /* [set up the fixed part of the buffer for a transfer] */ bp->b_dev = dev; bp->b_proc = p; buf_seterror(bp, 0); /* * [while there is data to transfer and no I/O error] * Note that I/O errors are handled with a 'goto' at the bottom * of the 'while' loop. */ for (i = 0; i < uio->uio_iovcnt; i++) { while (uio_iov_len_at(uio, i) > 0) { /* * [mark the buffer busy for physical I/O] * (i.e. set B_PHYS (because it's an I/O to user * memory, and B_RAW, because B_RAW is to be * "Set by physio for raw transfers.", in addition * to the read/write flag.) */ buf_setflags(bp, B_PHYS | B_RAW | flags); if ( (iosize = uio_iov_len_at(uio, i)) > MAXPHYSIO_WIRED) iosize = MAXPHYSIO_WIRED; /* [set up the buffer for a maximum-sized transfer] */ buf_setblkno(bp, uio->uio_offset / blocksize); buf_setcount(bp, iosize); // LP64todo - fix this! buf_setdataptr(bp, CAST_DOWN(caddr_t, uio_iov_base_at(uio, i))); /* * [call minphys to bound the tranfer size] * and remember the amount of data to transfer, * for later comparison. */ (*minphys)(bp); todo = buf_count(bp); /* * [lock the part of the user address space involved * in the transfer] */ if(UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) vslock(CAST_USER_ADDR_T(buf_dataptr(bp)), (user_size_t)todo); /* [call strategy to start the transfer] */ (*strategy)(bp); /* [wait for the transfer to complete] */ error = (int)buf_biowait(bp); /* * [unlock the part of the address space previously * locked] */ if(UIO_SEG_IS_USER_SPACE(uio->uio_segflg)) vsunlock(CAST_USER_ADDR_T(buf_dataptr(bp)), (user_size_t)todo, (flags & B_READ)); /* * [deduct the transfer size from the total number * of data to transfer] */ done = buf_count(bp) - buf_resid(bp); uio_iov_len_add_at(uio, -done, i); uio_iov_base_add_at(uio, done, i); uio->uio_offset += done; uio_setresid(uio, (uio_resid(uio) - done)); /* * Now, check for an error. * Also, handle weird end-of-disk semantics. */ if (error || done < todo) goto done; } } done: /* * [clean up the state of the buffer] * Remember if somebody wants it, so we can wake them up below. * Also, if we had to steal it, give it back. */ buf_clearflags(bp, B_PHYS | B_RAW); if (nobuf) buf_free(bp); else { buf_drop(bp); } return (error); } /* * Leffler, et al., says on p. 231: * "The minphys() routine is called by physio() to adjust the * size of each I/O transfer before the latter is passed to * the strategy routine..." * * so, just adjust the buffer's count accounting to MAXPHYS here, * and return the new count; */ u_int minphys(bp) struct buf *bp; { buf_setcount(bp, min(MAXPHYS, buf_count(bp))); return buf_count(bp); } /* * Do a read on a device for a user process. */ rawread(dev, uio) dev_t dev; struct uio *uio; { return (physio(cdevsw[major(dev)].d_strategy, (struct buf *)NULL, dev, B_READ, minphys, uio, DEV_BSIZE)); } /* * Do a write on a device for a user process. */ rawwrite(dev, uio) dev_t dev; struct uio *uio; { return (physio(cdevsw[major(dev)].d_strategy, (struct buf *)NULL, dev, B_WRITE, minphys, uio, DEV_BSIZE)); }