1 /*- 2 * Copyright (c) 2014 Andrew Turner 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 */ 27 28 #include <sys/param.h> 29 #include <sys/systm.h> 30 #include <sys/conf.h> 31 #include <sys/malloc.h> 32 #include <sys/memrange.h> 33 #include <sys/uio.h> 34 35 #include <machine/memdev.h> 36 #include <machine/vmparam.h> 37 38 #include <vm/vm.h> 39 #include <vm/pmap.h> 40 #include <vm/vm_extern.h> 41 #include <vm/vm_page.h> 42 43 struct mem_range_softc mem_range_softc; 44 45 int 46 memrw(struct cdev *dev, struct uio *uio, int flags) 47 { 48 ssize_t orig_resid; 49 vm_offset_t off, v; 50 struct iovec *iov; 51 struct vm_page m; 52 vm_page_t marr; 53 u_int cnt; 54 int error; 55 56 error = 0; 57 orig_resid = uio->uio_resid; 58 while (uio->uio_resid > 0 && error == 0) { 59 iov = uio->uio_iov; 60 if (iov->iov_len == 0) { 61 uio->uio_iov++; 62 uio->uio_iovcnt--; 63 if (uio->uio_iovcnt < 0) 64 panic("memrw"); 65 continue; 66 } 67 68 v = uio->uio_offset; 69 off = v & PAGE_MASK; 70 cnt = ulmin(iov->iov_len, PAGE_SIZE - (u_int)off); 71 if (cnt == 0) 72 continue; 73 74 switch(dev2unit(dev)) { 75 case CDEV_MINOR_KMEM: 76 /* If the address is in the DMAP just copy it */ 77 if (VIRT_IN_DMAP(v)) { 78 error = uiomove((void *)v, cnt, uio); 79 break; 80 } 81 82 if (!kernacc((void *)v, cnt, uio->uio_rw == UIO_READ ? 83 VM_PROT_READ : VM_PROT_WRITE)) { 84 error = EFAULT; 85 break; 86 } 87 88 /* Get the physical address to read */ 89 v = pmap_extract(kernel_pmap, v); 90 if (v == 0) { 91 error = EFAULT; 92 break; 93 } 94 95 /* FALLTHROUGH */ 96 case CDEV_MINOR_MEM: 97 /* If within the DMAP use this to copy from */ 98 if (PHYS_IN_DMAP(v)) { 99 v = PHYS_TO_DMAP(v); 100 error = uiomove((void *)v, cnt, uio); 101 break; 102 } 103 104 /* Have uiomove_fromphys handle the data */ 105 m.phys_addr = trunc_page(v); 106 marr = &m; 107 uiomove_fromphys(&marr, off, cnt, uio); 108 break; 109 } 110 } 111 112 /* 113 * Don't return error if any byte was written. Read and write 114 * can return error only if no i/o was performed. 115 */ 116 if (uio->uio_resid != orig_resid) 117 error = 0; 118 119 return (error); 120 } 121 122 /* 123 * Allow user processes to MMAP some memory sections 124 * instead of going through read/write. 125 */ 126 int 127 memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, 128 int prot __unused, vm_memattr_t *memattr __unused) 129 { 130 if (dev2unit(dev) == CDEV_MINOR_MEM) { 131 *paddr = offset; 132 return (0); 133 } 134 return (-1); 135 } 136 137 int 138 memioctl_md(struct cdev *dev __unused, u_long cmd __unused, 139 caddr_t data __unused, int flags __unused, struct thread *td __unused) 140 { 141 return (ENOTTY); 142 } 143