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 7.6 (Berkeley) 05/04/92 13 */ 14 15 /* 16 * Page to/from special files. 17 */ 18 19 #include "devpager.h" 20 #if NDEVPAGER > 0 21 22 #include <sys/param.h> 23 #include <sys/systm.h> 24 #include <sys/conf.h> 25 #include <sys/mman.h> 26 #include <sys/malloc.h> 27 28 #include <vm/vm.h> 29 #include <vm/vm_kern.h> 30 #include <vm/vm_page.h> 31 #include <vm/device_pager.h> 32 33 queue_head_t dev_pager_list; /* list of managed devices */ 34 35 #ifdef DEBUG 36 int dpagerdebug = 0; 37 #define DDB_FOLLOW 0x01 38 #define DDB_INIT 0x02 39 #define DDB_ALLOC 0x04 40 #define DDB_FAIL 0x08 41 #endif 42 43 static vm_pager_t dev_pager_alloc __P((caddr_t, vm_size_t, vm_prot_t)); 44 static void dev_pager_dealloc __P((vm_pager_t)); 45 static int dev_pager_getpage 46 __P((vm_pager_t, vm_page_t, boolean_t)); 47 static boolean_t dev_pager_haspage __P((vm_pager_t, vm_offset_t)); 48 static void dev_pager_init __P((void)); 49 static int dev_pager_putpage 50 __P((vm_pager_t, vm_page_t, boolean_t)); 51 52 struct pagerops devicepagerops = { 53 dev_pager_init, 54 dev_pager_alloc, 55 dev_pager_dealloc, 56 dev_pager_getpage, 57 dev_pager_putpage, 58 dev_pager_haspage 59 }; 60 61 static void 62 dev_pager_init() 63 { 64 #ifdef DEBUG 65 if (dpagerdebug & DDB_FOLLOW) 66 printf("dev_pager_init()\n"); 67 #endif 68 queue_init(&dev_pager_list); 69 } 70 71 static vm_pager_t 72 dev_pager_alloc(handle, size, prot) 73 caddr_t handle; 74 vm_size_t size; 75 vm_prot_t prot; 76 { 77 dev_t dev; 78 vm_pager_t pager; 79 int (*mapfunc)(), nprot; 80 register vm_object_t object; 81 register vm_page_t page; 82 register dev_pager_t devp; 83 register int npages, off; 84 extern int nullop(), enodev(); 85 86 87 #ifdef DEBUG 88 if (dpagerdebug & DDB_FOLLOW) 89 printf("dev_pager_alloc(%x, %x, %x)\n", handle, size, prot); 90 #endif 91 /* 92 * Pageout to device, should never happen. 93 */ 94 if (handle == NULL) 95 panic("dev_pager_alloc called"); 96 97 /* 98 * Look it up, creating as necessary 99 */ 100 pager = vm_pager_lookup(&dev_pager_list, handle); 101 if (pager == NULL) { 102 /* 103 * Validation. Make sure this device can be mapped 104 * and that range to map is acceptible to device. 105 */ 106 dev = (dev_t)handle; 107 mapfunc = cdevsw[major(dev)].d_mmap; 108 if (!mapfunc || mapfunc == enodev || mapfunc == nullop) 109 return(NULL); 110 nprot = 0; 111 if (prot & VM_PROT_READ) 112 nprot |= PROT_READ; 113 if (prot & VM_PROT_WRITE) 114 nprot |= PROT_WRITE; 115 if (prot & VM_PROT_EXECUTE) 116 nprot |= PROT_EXEC; 117 npages = atop(round_page(size)); 118 for (off = 0; npages--; off += PAGE_SIZE) 119 if ((*mapfunc)(dev, off, nprot) == -1) 120 return(NULL); 121 /* 122 * Allocate and initialize pager structs 123 */ 124 pager = (vm_pager_t)malloc(sizeof *pager, M_VMPAGER, M_WAITOK); 125 if (pager == NULL) 126 return(NULL); 127 devp = (dev_pager_t)malloc(sizeof *devp, M_VMPGDATA, M_WAITOK); 128 if (devp == NULL) { 129 free((caddr_t)pager, M_VMPAGER); 130 return(NULL); 131 } 132 devp->devp_dev = dev; 133 devp->devp_npages = atop(round_page(size)); 134 pager->pg_handle = handle; 135 pager->pg_ops = &devicepagerops; 136 pager->pg_type = PG_DEVICE; 137 pager->pg_data = (caddr_t)devp; 138 /* 139 * Allocate object and vm_page structures to describe memory 140 */ 141 npages = devp->devp_npages; 142 object = devp->devp_object = vm_object_allocate(ptoa(npages)); 143 vm_object_enter(object, pager); 144 vm_object_setpager(object, pager, (vm_offset_t)0, FALSE); 145 devp->devp_pages = (vm_page_t) 146 kmem_alloc(kernel_map, npages*sizeof(struct vm_page)); 147 off = 0; 148 for (page = devp->devp_pages; 149 page < &devp->devp_pages[npages]; page++) { 150 vm_object_lock(object); 151 VM_PAGE_INIT(page, object, off); 152 page->phys_addr = 153 pmap_phys_address((*mapfunc)(dev, off, nprot)); 154 page->wire_count = 1; 155 page->fictitious = TRUE; 156 PAGE_WAKEUP(page); 157 vm_object_unlock(object); 158 off += PAGE_SIZE; 159 } 160 /* 161 * Finally, put it on the managed list so other can find it. 162 */ 163 queue_enter(&dev_pager_list, devp, dev_pager_t, devp_list); 164 #ifdef DEBUG 165 if (dpagerdebug & DDB_ALLOC) { 166 printf("dev_pager_alloc: pages %d@%x\n", 167 devp->devp_npages, devp->devp_pages); 168 printf("dev_pager_alloc: pager %x devp %x object %x\n", 169 pager, devp, object); 170 vm_object_print(object, FALSE); 171 } 172 #endif 173 } else { 174 /* 175 * vm_object_lookup() gains a reference and also 176 * removes the object from the cache. 177 */ 178 devp = (dev_pager_t)pager->pg_data; 179 if (vm_object_lookup(pager) != devp->devp_object) 180 panic("dev_pager_setup: bad object"); 181 } 182 return(pager); 183 184 } 185 186 static void 187 dev_pager_dealloc(pager) 188 vm_pager_t pager; 189 { 190 dev_pager_t devp = (dev_pager_t)pager->pg_data; 191 register vm_object_t object; 192 193 #ifdef DEBUG 194 if (dpagerdebug & DDB_FOLLOW) 195 printf("dev_pager_dealloc(%x)\n", pager); 196 #endif 197 queue_remove(&dev_pager_list, devp, dev_pager_t, devp_list); 198 object = devp->devp_object; 199 #ifdef DEBUG 200 if (dpagerdebug & DDB_ALLOC) 201 printf("dev_pager_dealloc: devp %x object %x pages %d@%x\n", 202 devp, object, devp->devp_npages, devp->devp_pages); 203 #endif 204 while (!queue_empty(&object->memq)) 205 vm_page_remove((vm_page_t)queue_first(&object->memq)); 206 kmem_free(kernel_map, (vm_offset_t)devp->devp_pages, 207 devp->devp_npages * sizeof(struct vm_page)); 208 free((caddr_t)devp, M_VMPGDATA); 209 pager->pg_data = 0; 210 } 211 212 static int 213 dev_pager_getpage(pager, m, sync) 214 vm_pager_t pager; 215 vm_page_t m; 216 boolean_t sync; 217 { 218 #ifdef DEBUG 219 if (dpagerdebug & DDB_FOLLOW) 220 printf("dev_pager_getpage(%x, %x)\n", pager, m); 221 #endif 222 return(VM_PAGER_BAD); 223 } 224 225 static int 226 dev_pager_putpage(pager, m, sync) 227 vm_pager_t pager; 228 vm_page_t m; 229 boolean_t sync; 230 { 231 #ifdef DEBUG 232 if (dpagerdebug & DDB_FOLLOW) 233 printf("dev_pager_putpage(%x, %x)\n", pager, m); 234 #endif 235 if (pager == NULL) 236 return; 237 panic("dev_pager_putpage called"); 238 } 239 240 static boolean_t 241 dev_pager_haspage(pager, offset) 242 vm_pager_t pager; 243 vm_offset_t offset; 244 { 245 #ifdef DEBUG 246 if (dpagerdebug & DDB_FOLLOW) 247 printf("dev_pager_haspage(%x, %x)\n", pager, offset); 248 #endif 249 return(TRUE); 250 } 251 #endif 252