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("$FreeBSD$"); 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/sx.h> 57 #include <sys/proc.h> 58 #include <sys/signalvar.h> 59 #include <sys/systm.h> 60 #include <sys/uio.h> 61 62 #include <machine/specialreg.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 */ 73 MALLOC_DEFINE(M_MEMDESC, "memdesc", "memory range descriptors"); 74 75 static struct sx memsxlock; 76 SX_SYSINIT(memsxlockinit, &memsxlock, "/dev/mem lock"); 77 78 79 /* ARGSUSED */ 80 int 81 memrw(struct cdev *dev, struct uio *uio, int flags) 82 { 83 int o; 84 u_int c = 0; 85 vm_paddr_t pa; 86 struct iovec *iov; 87 int error = 0; 88 vm_offset_t addr; 89 90 /* XXX UPS Why ? */ 91 GIANT_REQUIRED; 92 93 94 if (dev2unit(dev) != CDEV_MINOR_MEM && dev2unit(dev) != CDEV_MINOR_KMEM) 95 return EIO; 96 97 if (dev2unit(dev) == CDEV_MINOR_KMEM && uio->uio_resid > 0) { 98 if (uio->uio_offset < (vm_offset_t)VADDR(PTDPTDI, 0)) 99 return (EFAULT); 100 101 if (!kernacc((caddr_t)(int)uio->uio_offset, uio->uio_resid, 102 uio->uio_rw == UIO_READ ? VM_PROT_READ : VM_PROT_WRITE)) 103 return (EFAULT); 104 } 105 106 while (uio->uio_resid > 0 && error == 0) { 107 iov = uio->uio_iov; 108 if (iov->iov_len == 0) { 109 uio->uio_iov++; 110 uio->uio_iovcnt--; 111 if (uio->uio_iovcnt < 0) 112 panic("memrw"); 113 continue; 114 } 115 if (dev2unit(dev) == CDEV_MINOR_MEM) { 116 pa = uio->uio_offset; 117 pa &= ~PAGE_MASK; 118 } else { 119 /* 120 * Extract the physical page since the mapping may 121 * change at any time. This avoids panics on page 122 * fault in this case but will cause reading/writing 123 * to the wrong page. 124 * Hopefully an application will notice the wrong 125 * data on read access and refrain from writing. 126 * This should be replaced by a special uiomove 127 * type function that just returns an error if there 128 * is a page fault on a kernel page. 129 */ 130 addr = trunc_page(uio->uio_offset); 131 pa = pmap_extract(kernel_pmap, addr); 132 if (pa == 0) 133 return EFAULT; 134 135 } 136 137 /* 138 * XXX UPS This should just use sf_buf_alloc. 139 * Unfortunately sf_buf_alloc needs a vm_page 140 * and we may want to look at memory not covered 141 * by the page array. 142 */ 143 144 sx_xlock(&memsxlock); 145 pmap_kenter((vm_offset_t)ptvmmap, pa); 146 pmap_invalidate_page(kernel_pmap,(vm_offset_t)ptvmmap); 147 148 o = (int)uio->uio_offset & PAGE_MASK; 149 c = PAGE_SIZE - o; 150 c = min(c, (u_int)iov->iov_len); 151 error = uiomove((caddr_t)&ptvmmap[o], (int)c, uio); 152 pmap_qremove((vm_offset_t)ptvmmap, 1); 153 sx_xunlock(&memsxlock); 154 155 } 156 157 return (error); 158 } 159 160 /* 161 * allow user processes to MMAP some memory sections 162 * instead of going through read/write 163 */ 164 /* ARGSUSED */ 165 int 166 memmmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, 167 int prot __unused) 168 { 169 if (dev2unit(dev) == CDEV_MINOR_MEM) 170 *paddr = offset; 171 else if (dev2unit(dev) == CDEV_MINOR_KMEM) 172 *paddr = vtophys(offset); 173 /* else panic! */ 174 return (0); 175 } 176 177 /* 178 * Operations for changing memory attributes. 179 * 180 * This is basically just an ioctl shim for mem_range_attr_get 181 * and mem_range_attr_set. 182 */ 183 /* ARGSUSED */ 184 int 185 memioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, int flags, 186 struct thread *td) 187 { 188 int nd, error = 0; 189 struct mem_range_op *mo = (struct mem_range_op *)data; 190 struct mem_range_desc *md; 191 192 /* is this for us? */ 193 if ((cmd != MEMRANGE_GET) && 194 (cmd != MEMRANGE_SET)) 195 return (ENOTTY); 196 197 /* any chance we can handle this? */ 198 if (mem_range_softc.mr_op == NULL) 199 return (EOPNOTSUPP); 200 201 /* do we have any descriptors? */ 202 if (mem_range_softc.mr_ndesc == 0) 203 return (ENXIO); 204 205 switch (cmd) { 206 case MEMRANGE_GET: 207 nd = imin(mo->mo_arg[0], mem_range_softc.mr_ndesc); 208 if (nd > 0) { 209 md = (struct mem_range_desc *) 210 malloc(nd * sizeof(struct mem_range_desc), 211 M_MEMDESC, M_WAITOK); 212 error = mem_range_attr_get(md, &nd); 213 if (!error) 214 error = copyout(md, mo->mo_desc, 215 nd * sizeof(struct mem_range_desc)); 216 free(md, M_MEMDESC); 217 } 218 else 219 nd = mem_range_softc.mr_ndesc; 220 mo->mo_arg[0] = nd; 221 break; 222 223 case MEMRANGE_SET: 224 md = (struct mem_range_desc *)malloc(sizeof(struct mem_range_desc), 225 M_MEMDESC, M_WAITOK); 226 error = copyin(mo->mo_desc, md, sizeof(struct mem_range_desc)); 227 /* clamp description string */ 228 md->mr_owner[sizeof(md->mr_owner) - 1] = 0; 229 if (error == 0) 230 error = mem_range_attr_set(md, &mo->mo_arg[0]); 231 free(md, M_MEMDESC); 232 break; 233 } 234 return (error); 235 } 236 237 void 238 dev_mem_md_init(void) 239 { 240 if (mem_range_softc.mr_op != NULL) 241 mem_range_softc.mr_op->init(&mem_range_softc); 242 } 243