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