1 /* 2 * Copyright (c) 1990 University of Utah. 3 * Copyright (c) 1991 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. 9 * 10 * %sccs.include.redist.c% 11 * 12 * @(#)device_pager.c 7.1 (Berkeley) 12/05/90 13 */ 14 15 /* 16 * Page to/from special files. 17 */ 18 19 #include "devpager.h" 20 #if NDEVPAGER > 0 21 22 #include "param.h" 23 #include "queue.h" 24 #include "conf.h" 25 #include "mman.h" 26 #include "malloc.h" 27 #include "uio.h" 28 29 #include "../vm/vm_param.h" 30 #include "../vm/vm_map.h" 31 #include "../vm/vm_pager.h" 32 #include "../vm/vm_page.h" 33 #include "../vm/vm_kern.h" 34 #include "../vm/device_pager.h" 35 36 queue_head_t dev_pager_list; /* list of managed devices */ 37 38 #ifdef DEBUG 39 int dpagerdebug = 0; 40 #define DDB_FOLLOW 0x01 41 #define DDB_INIT 0x02 42 #define DDB_ALLOC 0x04 43 #define DDB_FAIL 0x08 44 #endif 45 46 void 47 dev_pager_init() 48 { 49 #ifdef DEBUG 50 if (dpagerdebug & DDB_FOLLOW) 51 printf("dev_pager_init()\n"); 52 #endif 53 queue_init(&dev_pager_list); 54 } 55 56 vm_pager_t 57 dev_pager_alloc(handle, size, prot) 58 caddr_t handle; 59 vm_size_t size; 60 vm_prot_t prot; 61 { 62 dev_t dev; 63 vm_pager_t pager; 64 int (*mapfunc)(), nprot; 65 register vm_object_t object; 66 register vm_page_t page; 67 register dev_pager_t devp; 68 register int npages, off; 69 extern int nulldev(), nodev(); 70 71 72 #ifdef DEBUG 73 if (dpagerdebug & DDB_FOLLOW) 74 printf("dev_pager_alloc(%x, %x, %x)\n", handle, size, prot); 75 #endif 76 /* 77 * Pageout to device, should never happen. 78 */ 79 if (handle == NULL) 80 panic("dev_pager_alloc called"); 81 82 /* 83 * Look it up, creating as necessary 84 */ 85 pager = vm_pager_lookup(&dev_pager_list, handle); 86 if (pager == VM_PAGER_NULL) { 87 /* 88 * Validation. Make sure this device can be mapped 89 * and that range to map is acceptible to device. 90 */ 91 dev = (dev_t)handle; 92 mapfunc = cdevsw[major(dev)].d_mmap; 93 if (!mapfunc || mapfunc == nodev || mapfunc == nulldev) 94 return(VM_PAGER_NULL); 95 nprot = 0; 96 if (prot & VM_PROT_READ) 97 nprot |= PROT_READ; 98 if (prot & VM_PROT_WRITE) 99 nprot |= PROT_WRITE; 100 if (prot & VM_PROT_EXECUTE) 101 nprot |= PROT_EXEC; 102 npages = atop(round_page(size)); 103 for (off = 0; npages--; off += PAGE_SIZE) 104 if ((*mapfunc)(dev, off, nprot) == -1) 105 return(VM_PAGER_NULL); 106 /* 107 * Allocate and initialize pager structs 108 */ 109 pager = (vm_pager_t)malloc(sizeof *pager, M_VMPAGER, M_WAITOK); 110 if (pager == VM_PAGER_NULL) 111 return(VM_PAGER_NULL); 112 devp = (dev_pager_t)malloc(sizeof *devp, M_VMPGDATA, M_WAITOK); 113 if (devp == DEV_PAGER_NULL) { 114 free((caddr_t)pager, M_VMPAGER); 115 return(VM_PAGER_NULL); 116 } 117 devp->devp_dev = dev; 118 devp->devp_npages = atop(round_page(size)); 119 pager->pg_handle = handle; 120 pager->pg_ops = &devicepagerops; 121 pager->pg_type = PG_DEVICE; 122 pager->pg_data = (caddr_t)devp; 123 /* 124 * Allocate object and vm_page structures to describe memory 125 */ 126 npages = devp->devp_npages; 127 object = devp->devp_object = vm_object_allocate(ptoa(npages)); 128 vm_object_enter(object, pager); 129 vm_object_setpager(object, pager, (vm_offset_t)0, FALSE); 130 devp->devp_pages = (vm_page_t) 131 kmem_alloc(kernel_map, npages*sizeof(struct vm_page)); 132 off = 0; 133 for (page = devp->devp_pages; 134 page < &devp->devp_pages[npages]; page++) { 135 vm_object_lock(object); 136 vm_page_init(page, object, off); 137 page->phys_addr = 138 pmap_phys_address((*mapfunc)(dev, off, nprot)); 139 page->wire_count = 1; 140 page->fictitious = TRUE; 141 PAGE_WAKEUP(page); 142 vm_object_unlock(object); 143 off += PAGE_SIZE; 144 } 145 /* 146 * Finally, put it on the managed list so other can find it. 147 */ 148 queue_enter(&dev_pager_list, devp, dev_pager_t, devp_list); 149 #ifdef DEBUG 150 if (dpagerdebug & DDB_ALLOC) 151 printf("dev_pager_alloc: pages %d@%x\n", 152 devp->devp_npages, devp->devp_pages); 153 #endif 154 } else { 155 /* 156 * vm_object_lookup() gains a reference and also 157 * removes the object from the cache. 158 */ 159 devp = (dev_pager_t)pager->pg_data; 160 if (vm_object_lookup(pager) != devp->devp_object) 161 panic("dev_pager_setup: bad object"); 162 } 163 #ifdef DEBUG 164 if (dpagerdebug & DDB_ALLOC) { 165 printf("dev_pager_alloc: pager %x devp %x object %x\n", 166 pager, devp, object); 167 vm_object_print(object, FALSE); 168 } 169 #endif 170 return(pager); 171 172 } 173 174 void 175 dev_pager_dealloc(pager) 176 vm_pager_t pager; 177 { 178 dev_pager_t devp = (dev_pager_t)pager->pg_data; 179 register vm_object_t object; 180 181 #ifdef DEBUG 182 if (dpagerdebug & DDB_FOLLOW) 183 printf("dev_pager_dealloc(%x)\n", pager); 184 #endif 185 queue_remove(&dev_pager_list, devp, dev_pager_t, devp_list); 186 object = devp->devp_object; 187 #ifdef DEBUG 188 if (dpagerdebug & DDB_ALLOC) 189 printf("dev_pager_dealloc: devp %x object %x pages %d@%x\n", 190 devp, object, devp->devp_npages, devp->devp_pages); 191 #endif 192 while (!queue_empty(&object->memq)) 193 vm_page_remove((vm_page_t)queue_first(&object->memq)); 194 kmem_free(kernel_map, devp->devp_pages, 195 devp->devp_npages * sizeof(struct vm_page)); 196 free((caddr_t)devp, M_VMPGDATA); 197 pager->pg_data = 0; 198 } 199 200 dev_pager_getpage(pager, m, sync) 201 vm_pager_t pager; 202 vm_page_t m; 203 boolean_t sync; 204 { 205 #ifdef DEBUG 206 if (dpagerdebug & DDB_FOLLOW) 207 printf("dev_pager_getpage(%x, %x)\n", pager, m); 208 #endif 209 return(VM_PAGER_BAD); 210 } 211 212 dev_pager_putpage(pager, m, sync) 213 vm_pager_t pager; 214 vm_page_t m; 215 boolean_t sync; 216 { 217 #ifdef DEBUG 218 if (dpagerdebug & DDB_FOLLOW) 219 printf("dev_pager_putpage(%x, %x)\n", pager, m); 220 #endif 221 if (pager == VM_PAGER_NULL) 222 return; 223 panic("dev_pager_putpage called"); 224 } 225 226 boolean_t 227 dev_pager_haspage(pager, offset) 228 vm_pager_t pager; 229 vm_offset_t offset; 230 { 231 #ifdef DEBUG 232 if (dpagerdebug & DDB_FOLLOW) 233 printf("dev_pager_haspage(%x, %x)\n", pager, offset); 234 #endif 235 return(TRUE); 236 } 237 #endif 238