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 */ 39 40 #include <sys/cdefs.h> 41 /* 42 * Memory special file 43 */ 44 45 #include <sys/param.h> 46 #include <sys/conf.h> 47 #include <sys/fcntl.h> 48 #include <sys/ioccom.h> 49 #include <sys/kernel.h> 50 #include <sys/lock.h> 51 #include <sys/malloc.h> 52 #include <sys/memrange.h> 53 #include <sys/module.h> 54 #include <sys/mutex.h> 55 #include <sys/sx.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 63 #include <vm/vm.h> 64 #include <vm/pmap.h> 65 #include <vm/vm_extern.h> 66 67 #include <machine/memdev.h> 68 69 /* 70 * Used in /dev/mem drivers and elsewhere 71 */ 72 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); 73 74 static struct sx memsxlock; 75 SX_SYSINIT(memsxlockinit, &memsxlock, "/dev/mem lock"); 76 77 /* ARGSUSED */ 78 int 79 memrw(struct cdev *dev, struct uio *uio, int flags) 80 { 81 int o; 82 u_int c = 0; 83 vm_paddr_t pa; 84 struct iovec *iov; 85 int error = 0; 86 vm_offset_t addr; 87 88 if (dev2unit(dev) != CDEV_MINOR_MEM && dev2unit(dev) != CDEV_MINOR_KMEM) 89 return EIO; 90 91 if (dev2unit(dev) == CDEV_MINOR_KMEM && uio->uio_resid > 0) { 92 if (!kernacc((caddr_t)(int)uio->uio_offset, uio->uio_resid, 93 uio->uio_rw == UIO_READ ? VM_PROT_READ : VM_PROT_WRITE)) 94 return (EFAULT); 95 } 96 97 while (uio->uio_resid > 0 && error == 0) { 98 iov = uio->uio_iov; 99 if (iov->iov_len == 0) { 100 uio->uio_iov++; 101 uio->uio_iovcnt--; 102 if (uio->uio_iovcnt < 0) 103 panic("memrw"); 104 continue; 105 } 106 if (dev2unit(dev) == CDEV_MINOR_MEM) { 107 if (uio->uio_offset > cpu_getmaxphyaddr()) { 108 error = EFAULT; 109 break; 110 } 111 pa = trunc_page(uio->uio_offset); 112 } else { 113 /* 114 * Extract the physical page since the mapping may 115 * change at any time. This avoids panics on page 116 * fault in this case but will cause reading/writing 117 * to the wrong page. 118 * Hopefully an application will notice the wrong 119 * data on read access and refrain from writing. 120 * This should be replaced by a special uiomove 121 * type function that just returns an error if there 122 * is a page fault on a kernel page. 123 */ 124 addr = trunc_page(uio->uio_offset); 125 pa = pmap_extract(kernel_pmap, addr); 126 if (pa == 0) 127 return EFAULT; 128 } 129 130 /* 131 * XXX UPS This should just use sf_buf_alloc. 132 * Unfortunately sf_buf_alloc needs a vm_page 133 * and we may want to look at memory not covered 134 * by the page array. 135 */ 136 137 sx_xlock(&memsxlock); 138 pmap_kenter((vm_offset_t)ptvmmap, pa); 139 pmap_invalidate_page(kernel_pmap,(vm_offset_t)ptvmmap); 140 141 o = (int)uio->uio_offset & PAGE_MASK; 142 c = PAGE_SIZE - o; 143 c = min(c, (u_int)iov->iov_len); 144 error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio); 145 pmap_qremove((vm_offset_t)ptvmmap, 1); 146 sx_xunlock(&memsxlock); 147 } 148 149 return (error); 150 } 151 152 /* 153 * allow user processes to MMAP some memory sections 154 * instead of going through read/write 155 */ 156 /* ARGSUSED */ 157 int 158 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, 159 int prot __unused, vm_memattr_t *memattr __unused) 160 { 161 if (dev2unit(dev) == CDEV_MINOR_MEM) { 162 if (offset > cpu_getmaxphyaddr()) 163 return (-1); 164 *paddr = offset; 165 return (0); 166 } 167 return (-1); 168 } 169 170 /* 171 * Operations for changing memory attributes. 172 * 173 * This is basically just an ioctl shim for mem_range_attr_get 174 * and mem_range_attr_set. 175 */ 176 int 177 memioctl_md(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags, 178 struct thread *td) 179 { 180 int nd, error = 0; 181 struct mem_range_op *mo = (struct mem_range_op *)data; 182 struct mem_range_desc *md; 183 184 /* is this for us? */ 185 if ((cmd != MEMRANGE_GET) && 186 (cmd != MEMRANGE_SET)) 187 return (ENOTTY); 188 189 /* any chance we can handle this? */ 190 if (mem_range_softc.mr_op == NULL) 191 return (EOPNOTSUPP); 192 193 /* do we have any descriptors? */ 194 if (mem_range_softc.mr_ndesc == 0) 195 return (ENXIO); 196 197 switch (cmd) { 198 case MEMRANGE_GET: 199 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); 200 if (nd > 0) { 201 md = (struct mem_range_desc *) 202 malloc(nd * sizeof(struct mem_range_desc), 203 M_MEMDESC, M_WAITOK); 204 error = mem_range_attr_get(md, &nd); 205 if (!error) 206 error = copyout(md, mo->mo_desc, 207 nd * sizeof(struct mem_range_desc)); 208 free(md, M_MEMDESC); 209 } 210 else 211 nd = mem_range_softc.mr_ndesc; 212 mo->mo_arg[0] = nd; 213 break; 214 215 case MEMRANGE_SET: 216 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc), 217 M_MEMDESC, M_WAITOK); 218 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); 219 /* clamp description string */ 220 md->mr_owner[sizeof(md->mr_owner) - 1] = 0; 221 if (error == 0) 222 error = mem_range_attr_set(md, &mo->mo_arg[0]); 223 free(md, M_MEMDESC); 224 break; 225 } 226 return (error); 227 } 228