1 /* 2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 3 * Licensed under the GPL 4 */ 5 6 #include "linux/bootmem.h" 7 #include "linux/mm.h" 8 #include "linux/pfn.h" 9 #include "asm/page.h" 10 #include "as-layout.h" 11 #include "init.h" 12 #include "kern.h" 13 #include "mem_user.h" 14 #include "os.h" 15 16 static int physmem_fd = -1; 17 18 /* Changed during early boot */ 19 unsigned long high_physmem; 20 21 extern unsigned long long physmem_size; 22 23 int __init init_maps(unsigned long physmem, unsigned long iomem, 24 unsigned long highmem) 25 { 26 struct page *p, *map; 27 unsigned long phys_len, phys_pages, highmem_len, highmem_pages; 28 unsigned long iomem_len, iomem_pages, total_len, total_pages; 29 int i; 30 31 phys_pages = physmem >> PAGE_SHIFT; 32 phys_len = phys_pages * sizeof(struct page); 33 34 iomem_pages = iomem >> PAGE_SHIFT; 35 iomem_len = iomem_pages * sizeof(struct page); 36 37 highmem_pages = highmem >> PAGE_SHIFT; 38 highmem_len = highmem_pages * sizeof(struct page); 39 40 total_pages = phys_pages + iomem_pages + highmem_pages; 41 total_len = phys_len + iomem_len + highmem_len; 42 43 map = alloc_bootmem_low_pages(total_len); 44 if (map == NULL) 45 return -ENOMEM; 46 47 for (i = 0; i < total_pages; i++) { 48 p = &map[i]; 49 memset(p, 0, sizeof(struct page)); 50 SetPageReserved(p); 51 INIT_LIST_HEAD(&p->lru); 52 } 53 54 max_mapnr = total_pages; 55 return 0; 56 } 57 58 /* Changed during early boot */ 59 static unsigned long kmem_top = 0; 60 61 unsigned long get_kmem_end(void) 62 { 63 if (kmem_top == 0) 64 kmem_top = host_task_size - 1024 * 1024; 65 return kmem_top; 66 } 67 68 void map_memory(unsigned long virt, unsigned long phys, unsigned long len, 69 int r, int w, int x) 70 { 71 __u64 offset; 72 int fd, err; 73 74 fd = phys_mapping(phys, &offset); 75 err = os_map_memory((void *) virt, fd, offset, len, r, w, x); 76 if (err) { 77 if (err == -ENOMEM) 78 printk(KERN_ERR "try increasing the host's " 79 "/proc/sys/vm/max_map_count to <physical " 80 "memory size>/4096\n"); 81 panic("map_memory(0x%lx, %d, 0x%llx, %ld, %d, %d, %d) failed, " 82 "err = %d\n", virt, fd, offset, len, r, w, x, err); 83 } 84 } 85 86 extern int __syscall_stub_start; 87 88 void __init setup_physmem(unsigned long start, unsigned long reserve_end, 89 unsigned long len, unsigned long long highmem) 90 { 91 unsigned long reserve = reserve_end - start; 92 int pfn = PFN_UP(__pa(reserve_end)); 93 int delta = (len - reserve) >> PAGE_SHIFT; 94 int err, offset, bootmap_size; 95 96 physmem_fd = create_mem_file(len + highmem); 97 98 offset = uml_reserved - uml_physmem; 99 err = os_map_memory((void *) uml_reserved, physmem_fd, offset, 100 len - offset, 1, 1, 1); 101 if (err < 0) { 102 printf("setup_physmem - mapping %ld bytes of memory at 0x%p " 103 "failed - errno = %d\n", len - offset, 104 (void *) uml_reserved, err); 105 exit(1); 106 } 107 108 /* 109 * Special kludge - This page will be mapped in to userspace processes 110 * from physmem_fd, so it needs to be written out there. 111 */ 112 os_seek_file(physmem_fd, __pa(&__syscall_stub_start)); 113 os_write_file(physmem_fd, &__syscall_stub_start, PAGE_SIZE); 114 115 bootmap_size = init_bootmem(pfn, pfn + delta); 116 free_bootmem(__pa(reserve_end) + bootmap_size, 117 len - bootmap_size - reserve); 118 } 119 120 int phys_mapping(unsigned long phys, unsigned long long *offset_out) 121 { 122 int fd = -1; 123 124 if (phys < physmem_size) { 125 fd = physmem_fd; 126 *offset_out = phys; 127 } 128 else if (phys < __pa(end_iomem)) { 129 struct iomem_region *region = iomem_regions; 130 131 while (region != NULL) { 132 if ((phys >= region->phys) && 133 (phys < region->phys + region->size)) { 134 fd = region->fd; 135 *offset_out = phys - region->phys; 136 break; 137 } 138 region = region->next; 139 } 140 } 141 else if (phys < __pa(end_iomem) + highmem) { 142 fd = physmem_fd; 143 *offset_out = phys - iomem_size; 144 } 145 146 return fd; 147 } 148 149 static int __init uml_mem_setup(char *line, int *add) 150 { 151 char *retptr; 152 physmem_size = memparse(line,&retptr); 153 return 0; 154 } 155 __uml_setup("mem=", uml_mem_setup, 156 "mem=<Amount of desired ram>\n" 157 " This controls how much \"physical\" memory the kernel allocates\n" 158 " for the system. The size is specified as a number followed by\n" 159 " one of 'k', 'K', 'm', 'M', which have the obvious meanings.\n" 160 " This is not related to the amount of memory in the host. It can\n" 161 " be more, and the excess, if it's ever used, will just be swapped out.\n" 162 " Example: mem=64M\n\n" 163 ); 164 165 extern int __init parse_iomem(char *str, int *add); 166 167 __uml_setup("iomem=", parse_iomem, 168 "iomem=<name>,<file>\n" 169 " Configure <file> as an IO memory region named <name>.\n\n" 170 ); 171 172 /* 173 * This list is constructed in parse_iomem and addresses filled in in 174 * setup_iomem, both of which run during early boot. Afterwards, it's 175 * unchanged. 176 */ 177 struct iomem_region *iomem_regions = NULL; 178 179 /* Initialized in parse_iomem */ 180 int iomem_size = 0; 181 182 unsigned long find_iomem(char *driver, unsigned long *len_out) 183 { 184 struct iomem_region *region = iomem_regions; 185 186 while (region != NULL) { 187 if (!strcmp(region->driver, driver)) { 188 *len_out = region->size; 189 return region->virt; 190 } 191 192 region = region->next; 193 } 194 195 return 0; 196 } 197 198 int setup_iomem(void) 199 { 200 struct iomem_region *region = iomem_regions; 201 unsigned long iomem_start = high_physmem + PAGE_SIZE; 202 int err; 203 204 while (region != NULL) { 205 err = os_map_memory((void *) iomem_start, region->fd, 0, 206 region->size, 1, 1, 0); 207 if (err) 208 printk(KERN_ERR "Mapping iomem region for driver '%s' " 209 "failed, errno = %d\n", region->driver, -err); 210 else { 211 region->virt = iomem_start; 212 region->phys = __pa(region->virt); 213 } 214 215 iomem_start += region->size + PAGE_SIZE; 216 region = region->next; 217 } 218 219 return 0; 220 } 221 222 __initcall(setup_iomem); 223