mem.c revision 263875
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/10/sys/amd64/amd64/mem.c 263875 2014-03-28 15:38:38Z kib $"); 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/specialreg.h> 62#include <machine/vmparam.h> 63 64#include <vm/vm.h> 65#include <vm/pmap.h> 66#include <vm/vm_extern.h> 67 68#include <machine/memdev.h> 69 70/* 71 * Used in /dev/mem drivers and elsewhere 72 */ 73MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); 74 75/* ARGSUSED */ 76int 77memrw(struct cdev *dev, struct uio *uio, int flags) 78{ 79 struct iovec *iov; 80 u_long c, v; 81 int error, o, sflags; 82 vm_offset_t addr, eaddr; 83 84 GIANT_REQUIRED; 85 86 error = 0; 87 c = 0; 88 sflags = curthread_pflags_set(TDP_DEVMEMIO); 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 if (dev2unit(dev) == CDEV_MINOR_MEM) { 99 v = uio->uio_offset; 100kmemphys: 101 o = v & PAGE_MASK; 102 c = min(uio->uio_resid, (u_int)(PAGE_SIZE - o)); 103 v = PHYS_TO_DMAP(v); 104 if (v < DMAP_MIN_ADDRESS || 105 (v > DMAP_MIN_ADDRESS + dmaplimit && 106 v <= DMAP_MAX_ADDRESS) || 107 pmap_kextract(v) == 0) { 108 error = EFAULT; 109 goto ret; 110 } 111 error = uiomove((void *)v, (int)c, uio); 112 continue; 113 } 114 else if (dev2unit(dev) == CDEV_MINOR_KMEM) { 115 v = uio->uio_offset; 116 117 if (v >= DMAP_MIN_ADDRESS && v < DMAP_MAX_ADDRESS) { 118 v = DMAP_TO_PHYS(v); 119 goto kmemphys; 120 } 121 122 c = iov->iov_len; 123 124 /* 125 * Make sure that all of the pages are currently 126 * resident so that we don't create any zero-fill 127 * pages. 128 */ 129 addr = trunc_page(v); 130 eaddr = round_page(v + c); 131 132 if (addr < VM_MIN_KERNEL_ADDRESS) { 133 error = EFAULT; 134 goto ret; 135 } 136 for (; addr < eaddr; addr += PAGE_SIZE) { 137 if (pmap_extract(kernel_pmap, addr) == 0) { 138 error = EFAULT; 139 goto ret; 140 } 141 } 142 if (!kernacc((caddr_t)(long)v, c, 143 uio->uio_rw == UIO_READ ? 144 VM_PROT_READ : VM_PROT_WRITE)) { 145 error = EFAULT; 146 goto ret; 147 } 148 149 error = uiomove((caddr_t)(long)v, (int)c, uio); 150 continue; 151 } 152 /* else panic! */ 153 } 154ret: 155 curthread_pflags_restore(sflags); 156 return (error); 157} 158 159/* 160 * allow user processes to MMAP some memory sections 161 * instead of going through read/write 162 */ 163/* ARGSUSED */ 164int 165memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, 166 int prot __unused, vm_memattr_t *memattr __unused) 167{ 168 if (dev2unit(dev) == CDEV_MINOR_MEM) 169 *paddr = offset; 170 else if (dev2unit(dev) == CDEV_MINOR_KMEM) 171 *paddr = vtophys(offset); 172 /* else panic! */ 173 return (0); 174} 175 176/* 177 * Operations for changing memory attributes. 178 * 179 * This is basically just an ioctl shim for mem_range_attr_get 180 * and mem_range_attr_set. 181 */ 182/* ARGSUSED */ 183int 184memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags, 185 struct thread *td) 186{ 187 int nd, error = 0; 188 struct mem_range_op *mo = (struct mem_range_op *)data; 189 struct mem_range_desc *md; 190 191 /* is this for us? */ 192 if ((cmd != MEMRANGE_GET) && 193 (cmd != MEMRANGE_SET)) 194 return (ENOTTY); 195 196 /* any chance we can handle this? */ 197 if (mem_range_softc.mr_op == NULL) 198 return (EOPNOTSUPP); 199 200 /* do we have any descriptors? */ 201 if (mem_range_softc.mr_ndesc == 0) 202 return (ENXIO); 203 204 switch (cmd) { 205 case MEMRANGE_GET: 206 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); 207 if (nd > 0) { 208 md = (struct mem_range_desc *) 209 malloc(nd * sizeof(struct mem_range_desc), 210 M_MEMDESC, M_WAITOK); 211 error = mem_range_attr_get(md, &nd); 212 if (!error) 213 error = copyout(md, mo->mo_desc, 214 nd * sizeof(struct mem_range_desc)); 215 free(md, M_MEMDESC); 216 } 217 else 218 nd = mem_range_softc.mr_ndesc; 219 mo->mo_arg[0] = nd; 220 break; 221 222 case MEMRANGE_SET: 223 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc), 224 M_MEMDESC, M_WAITOK); 225 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); 226 /* clamp description string */ 227 md->mr_owner[sizeof(md->mr_owner) - 1] = 0; 228 if (error == 0) 229 error = mem_range_attr_set(md, &mo->mo_arg[0]); 230 free(md, M_MEMDESC); 231 break; 232 } 233 return (error); 234} 235