File:  [DragonFly] / src / sys / kern / kern_physio.c
Revision 1.6: download - view: text, annotated - select for diffs
Mon Feb 9 21:51:28 2004 UTC (10 years, 10 months ago) by hmp
Branches: MAIN
CVS tags: HEAD
Merge from FreeBSD:

	Don't check block number overflow for D_MEM;
	/dev/fwmem needs 48-bit offsets.

    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: }