1 /* 2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 3 * Licensed under the GPL 4 */ 5 6 #include <linux/module.h> 7 #include <linux/bootmem.h> 8 #include <linux/mm.h> 9 #include <linux/pfn.h> 10 #include <asm/page.h> 11 #include <as-layout.h> 12 #include <init.h> 13 #include <kern.h> 14 #include <mem_user.h> 15 #include <os.h> 16 17 static int physmem_fd = -1; 18 19 /* Changed during early boot */ 20 unsigned long high_physmem; 21 EXPORT_SYMBOL(high_physmem); 22 23 extern unsigned long long physmem_size; 24 25 void __init mem_total_pages(unsigned long physmem, unsigned long iomem, 26 unsigned long highmem) 27 { 28 unsigned long phys_pages, highmem_pages; 29 unsigned long iomem_pages, total_pages; 30 31 phys_pages = physmem >> PAGE_SHIFT; 32 iomem_pages = iomem >> PAGE_SHIFT; 33 highmem_pages = highmem >> PAGE_SHIFT; 34 35 total_pages = phys_pages + iomem_pages + highmem_pages; 36 37 max_mapnr = total_pages; 38 } 39 40 void map_memory(unsigned long virt, unsigned long phys, unsigned long len, 41 int r, int w, int x) 42 { 43 __u64 offset; 44 int fd, err; 45 46 fd = phys_mapping(phys, &offset); 47 err = os_map_memory((void *) virt, fd, offset, len, r, w, x); 48 if (err) { 49 if (err == -ENOMEM) 50 printk(KERN_ERR "try increasing the host's " 51 "/proc/sys/vm/max_map_count to <physical " 52 "memory size>/4096\n"); 53 panic("map_memory(0x%lx, %d, 0x%llx, %ld, %d, %d, %d) failed, " 54 "err = %d\n", virt, fd, offset, len, r, w, x, err); 55 } 56 } 57 58 extern int __syscall_stub_start; 59 60 /** 61 * setup_physmem() - Setup physical memory for UML 62 * @start: Start address of the physical kernel memory, 63 * i.e start address of the executable image. 64 * @reserve_end: end address of the physical kernel memory. 65 * @len: Length of total physical memory that should be mapped/made 66 * available, in bytes. 67 * @highmem: Number of highmem bytes that should be mapped/made available. 68 * 69 * Creates an unlinked temporary file of size (len + highmem) and memory maps 70 * it on the last executable image address (uml_reserved). 71 * 72 * The offset is needed as the length of the total physical memory 73 * (len + highmem) includes the size of the memory used be the executable image, 74 * but the mapped-to address is the last address of the executable image 75 * (uml_reserved == end address of executable image). 76 * 77 * The memory mapped memory of the temporary file is used as backing memory 78 * of all user space processes/kernel tasks. 79 */ 80 void __init setup_physmem(unsigned long start, unsigned long reserve_end, 81 unsigned long len, unsigned long long highmem) 82 { 83 unsigned long reserve = reserve_end - start; 84 unsigned long pfn = PFN_UP(__pa(reserve_end)); 85 unsigned long delta = (len - reserve) >> PAGE_SHIFT; 86 unsigned long offset, bootmap_size; 87 long map_size; 88 int err; 89 90 offset = uml_reserved - uml_physmem; 91 map_size = len - offset; 92 if(map_size <= 0) { 93 printf("Too few physical memory! Needed=%d, given=%d\n", 94 offset, len); 95 exit(1); 96 } 97 98 physmem_fd = create_mem_file(len + highmem); 99 100 err = os_map_memory((void *) uml_reserved, physmem_fd, offset, 101 map_size, 1, 1, 1); 102 if (err < 0) { 103 printf("setup_physmem - mapping %ld bytes of memory at 0x%p " 104 "failed - errno = %d\n", map_size, 105 (void *) uml_reserved, err); 106 exit(1); 107 } 108 109 /* 110 * Special kludge - This page will be mapped in to userspace processes 111 * from physmem_fd, so it needs to be written out there. 112 */ 113 os_seek_file(physmem_fd, __pa(&__syscall_stub_start)); 114 os_write_file(physmem_fd, &__syscall_stub_start, PAGE_SIZE); 115 os_fsync_file(physmem_fd); 116 117 bootmap_size = init_bootmem(pfn, pfn + delta); 118 free_bootmem(__pa(reserve_end) + bootmap_size, 119 len - bootmap_size - reserve); 120 } 121 122 int phys_mapping(unsigned long phys, unsigned long long *offset_out) 123 { 124 int fd = -1; 125 126 if (phys < physmem_size) { 127 fd = physmem_fd; 128 *offset_out = phys; 129 } 130 else if (phys < __pa(end_iomem)) { 131 struct iomem_region *region = iomem_regions; 132 133 while (region != NULL) { 134 if ((phys >= region->phys) && 135 (phys < region->phys + region->size)) { 136 fd = region->fd; 137 *offset_out = phys - region->phys; 138 break; 139 } 140 region = region->next; 141 } 142 } 143 else if (phys < __pa(end_iomem) + highmem) { 144 fd = physmem_fd; 145 *offset_out = phys - iomem_size; 146 } 147 148 return fd; 149 } 150 151 static int __init uml_mem_setup(char *line, int *add) 152 { 153 char *retptr; 154 physmem_size = memparse(line,&retptr); 155 return 0; 156 } 157 __uml_setup("mem=", uml_mem_setup, 158 "mem=<Amount of desired ram>\n" 159 " This controls how much \"physical\" memory the kernel allocates\n" 160 " for the system. The size is specified as a number followed by\n" 161 " one of 'k', 'K', 'm', 'M', which have the obvious meanings.\n" 162 " This is not related to the amount of memory in the host. It can\n" 163 " be more, and the excess, if it's ever used, will just be swapped out.\n" 164 " Example: mem=64M\n\n" 165 ); 166 167 extern int __init parse_iomem(char *str, int *add); 168 169 __uml_setup("iomem=", parse_iomem, 170 "iomem=<name>,<file>\n" 171 " Configure <file> as an IO memory region named <name>.\n\n" 172 ); 173 174 /* 175 * This list is constructed in parse_iomem and addresses filled in in 176 * setup_iomem, both of which run during early boot. Afterwards, it's 177 * unchanged. 178 */ 179 struct iomem_region *iomem_regions; 180 181 /* Initialized in parse_iomem and unchanged thereafter */ 182 int iomem_size; 183 184 unsigned long find_iomem(char *driver, unsigned long *len_out) 185 { 186 struct iomem_region *region = iomem_regions; 187 188 while (region != NULL) { 189 if (!strcmp(region->driver, driver)) { 190 *len_out = region->size; 191 return region->virt; 192 } 193 194 region = region->next; 195 } 196 197 return 0; 198 } 199 EXPORT_SYMBOL(find_iomem); 200 201 static int setup_iomem(void) 202 { 203 struct iomem_region *region = iomem_regions; 204 unsigned long iomem_start = high_physmem + PAGE_SIZE; 205 int err; 206 207 while (region != NULL) { 208 err = os_map_memory((void *) iomem_start, region->fd, 0, 209 region->size, 1, 1, 0); 210 if (err) 211 printk(KERN_ERR "Mapping iomem region for driver '%s' " 212 "failed, errno = %d\n", region->driver, -err); 213 else { 214 region->virt = iomem_start; 215 region->phys = __pa(region->virt); 216 } 217 218 iomem_start += region->size + PAGE_SIZE; 219 region = region->next; 220 } 221 222 return 0; 223 } 224 225 __initcall(setup_iomem); 226