1 /*- 2 * Copyright (c) 2014 Andrew Turner 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, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/conf.h> 34 #include <sys/malloc.h> 35 #include <sys/memrange.h> 36 #include <sys/uio.h> 37 38 #include <machine/memdev.h> 39 #include <machine/vmparam.h> 40 41 #include <vm/vm.h> 42 #include <vm/pmap.h> 43 #include <vm/vm_extern.h> 44 #include <vm/vm_page.h> 45 46 struct mem_range_softc mem_range_softc; 47 48 int 49 memrw(struct cdev *dev, struct uio *uio, int flags) 50 { 51 ssize_t orig_resid; 52 vm_offset_t off, v; 53 struct iovec *iov; 54 struct vm_page m; 55 vm_page_t marr; 56 u_int cnt; 57 int error; 58 59 error = 0; 60 orig_resid = uio->uio_resid; 61 while (uio->uio_resid > 0 && error == 0) { 62 iov = uio->uio_iov; 63 if (iov->iov_len == 0) { 64 uio->uio_iov++; 65 uio->uio_iovcnt--; 66 if (uio->uio_iovcnt < 0) 67 panic("memrw"); 68 continue; 69 } 70 71 v = uio->uio_offset; 72 off = v & PAGE_MASK; 73 cnt = ulmin(iov->iov_len, PAGE_SIZE - (u_int)off); 74 if (cnt == 0) 75 continue; 76 77 switch(dev2unit(dev)) { 78 case CDEV_MINOR_KMEM: 79 /* If the address is in the DMAP just copy it */ 80 if (VIRT_IN_DMAP(v)) { 81 error = uiomove((void *)v, cnt, uio); 82 break; 83 } 84 85 if (!kernacc((void *)v, cnt, uio->uio_rw == UIO_READ ? 86 VM_PROT_READ : VM_PROT_WRITE)) { 87 error = EFAULT; 88 break; 89 } 90 91 /* Get the physical address to read */ 92 v = pmap_extract(kernel_pmap, v); 93 if (v == 0) { 94 error = EFAULT; 95 break; 96 } 97 98 /* FALLTHROUGH */ 99 case CDEV_MINOR_MEM: 100 /* If within the DMAP use this to copy from */ 101 if (PHYS_IN_DMAP(v)) { 102 v = PHYS_TO_DMAP(v); 103 error = uiomove((void *)v, cnt, uio); 104 break; 105 } 106 107 /* Have uiomove_fromphys handle the data */ 108 m.phys_addr = trunc_page(v); 109 marr = &m; 110 uiomove_fromphys(&marr, off, cnt, uio); 111 break; 112 } 113 } 114 115 /* 116 * Don't return error if any byte was written. Read and write 117 * can return error only if no i/o was performed. 118 */ 119 if (uio->uio_resid != orig_resid) 120 error = 0; 121 122 return (error); 123 } 124 125