mem.c revision 312394
1/*- 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California. 4 * All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department, and code derived from software contributed to 9 * Berkeley by William Jolitz. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * from: Utah $Hdr: mem.c 1.13 89/10/08$ 36 * from: @(#)mem.c 7.2 (Berkeley) 5/9/91 37 */ 38 39#include <sys/cdefs.h> 40__FBSDID("$FreeBSD: stable/11/sys/amd64/amd64/mem.c 312394 2017-01-18 19:38:53Z jhb $"); 41 42/* 43 * Memory special file 44 */ 45 46#include <sys/param.h> 47#include <sys/conf.h> 48#include <sys/fcntl.h> 49#include <sys/ioccom.h> 50#include <sys/kernel.h> 51#include <sys/lock.h> 52#include <sys/malloc.h> 53#include <sys/memrange.h> 54#include <sys/module.h> 55#include <sys/mutex.h> 56#include <sys/proc.h> 57#include <sys/signalvar.h> 58#include <sys/systm.h> 59#include <sys/uio.h> 60 61#include <machine/md_var.h> 62#include <machine/specialreg.h> 63#include <machine/vmparam.h> 64 65#include <vm/vm.h> 66#include <vm/pmap.h> 67#include <vm/vm_extern.h> 68 69#include <machine/memdev.h> 70 71/* 72 * Used in /dev/mem drivers and elsewhere 73 */ 74MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); 75 76/* ARGSUSED */ 77int 78memrw(struct cdev *dev, struct uio *uio, int flags) 79{ 80 struct iovec *iov; 81 void *p; 82 ssize_t orig_resid; 83 u_long v, vd; 84 u_int c; 85 int error; 86 87 error = 0; 88 orig_resid = uio->uio_resid; 89 while (uio->uio_resid > 0 && error == 0) { 90 iov = uio->uio_iov; 91 if (iov->iov_len == 0) { 92 uio->uio_iov++; 93 uio->uio_iovcnt--; 94 if (uio->uio_iovcnt < 0) 95 panic("memrw"); 96 continue; 97 } 98 v = uio->uio_offset; 99 c = ulmin(iov->iov_len, PAGE_SIZE - (u_int)(v & PAGE_MASK)); 100 101 switch (dev2unit(dev)) { 102 case CDEV_MINOR_KMEM: 103 /* 104 * Since c is clamped to be less or equal than 105 * PAGE_SIZE, the uiomove() call does not 106 * access past the end of the direct map. 107 */ 108 if (v >= DMAP_MIN_ADDRESS && 109 v < DMAP_MIN_ADDRESS + dmaplimit) { 110 error = uiomove((void *)v, c, uio); 111 break; 112 } 113 114 if (!kernacc((void *)v, c, uio->uio_rw == UIO_READ ? 115 VM_PROT_READ : VM_PROT_WRITE)) { 116 error = EFAULT; 117 break; 118 } 119 120 /* 121 * If the extracted address is not accessible 122 * through the direct map, then we make a 123 * private (uncached) mapping because we can't 124 * depend on the existing kernel mapping 125 * remaining valid until the completion of 126 * uiomove(). 127 * 128 * XXX We cannot provide access to the 129 * physical page 0 mapped into KVA. 130 */ 131 v = pmap_extract(kernel_pmap, v); 132 if (v == 0) { 133 error = EFAULT; 134 break; 135 } 136 /* FALLTHROUGH */ 137 case CDEV_MINOR_MEM: 138 if (v < dmaplimit) { 139 vd = PHYS_TO_DMAP(v); 140 error = uiomove((void *)vd, c, uio); 141 break; 142 } 143 if (v > cpu_getmaxphyaddr()) { 144 error = EFAULT; 145 break; 146 } 147 p = pmap_mapdev(v, PAGE_SIZE); 148 error = uiomove(p, c, uio); 149 pmap_unmapdev((vm_offset_t)p, PAGE_SIZE); 150 break; 151 } 152 } 153 /* 154 * Don't return error if any byte was written. Read and write 155 * can return error only if no i/o was performed. 156 */ 157 if (uio->uio_resid != orig_resid) 158 error = 0; 159 return (error); 160} 161 162/* 163 * allow user processes to MMAP some memory sections 164 * instead of going through read/write 165 */ 166/* ARGSUSED */ 167int 168memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, 169 int prot __unused, vm_memattr_t *memattr __unused) 170{ 171 if (dev2unit(dev) == CDEV_MINOR_MEM) { 172 if (offset > cpu_getmaxphyaddr()) 173 return (-1); 174 *paddr = offset; 175 return (0); 176 } 177 return (-1); 178} 179 180/* 181 * Operations for changing memory attributes. 182 * 183 * This is basically just an ioctl shim for mem_range_attr_get 184 * and mem_range_attr_set. 185 */ 186/* ARGSUSED */ 187int 188memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags, 189 struct thread *td) 190{ 191 int nd, error = 0; 192 struct mem_range_op *mo = (struct mem_range_op *)data; 193 struct mem_range_desc *md; 194 195 /* is this for us? */ 196 if ((cmd != MEMRANGE_GET) && 197 (cmd != MEMRANGE_SET)) 198 return (ENOTTY); 199 200 /* any chance we can handle this? */ 201 if (mem_range_softc.mr_op == NULL) 202 return (EOPNOTSUPP); 203 204 /* do we have any descriptors? */ 205 if (mem_range_softc.mr_ndesc == 0) 206 return (ENXIO); 207 208 switch (cmd) { 209 case MEMRANGE_GET: 210 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); 211 if (nd > 0) { 212 md = (struct mem_range_desc *) 213 malloc(nd * sizeof(struct mem_range_desc), 214 M_MEMDESC, M_WAITOK); 215 error = mem_range_attr_get(md, &nd); 216 if (!error) 217 error = copyout(md, mo->mo_desc, 218 nd * sizeof(struct mem_range_desc)); 219 free(md, M_MEMDESC); 220 } 221 else 222 nd = mem_range_softc.mr_ndesc; 223 mo->mo_arg[0] = nd; 224 break; 225 226 case MEMRANGE_SET: 227 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc), 228 M_MEMDESC, M_WAITOK); 229 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); 230 /* clamp description string */ 231 md->mr_owner[sizeof(md->mr_owner) - 1] = 0; 232 if (error == 0) 233 error = mem_range_attr_set(md, &mo->mo_arg[0]); 234 free(md, M_MEMDESC); 235 break; 236 } 237 return (error); 238} 239