Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/arch/m68k/motorola.c |
| 3 | * |
| 4 | * Routines specific to the Motorola MMU, originally from: |
| 5 | * linux/arch/m68k/init.c |
| 6 | * which are Copyright (C) 1995 Hamish Macdonald |
| 7 | * |
| 8 | * Moved 8/20/1999 Sam Creasey |
| 9 | */ |
| 10 | |
| 11 | #include <linux/config.h> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/signal.h> |
| 14 | #include <linux/sched.h> |
| 15 | #include <linux/mm.h> |
| 16 | #include <linux/swap.h> |
| 17 | #include <linux/kernel.h> |
| 18 | #include <linux/string.h> |
| 19 | #include <linux/types.h> |
| 20 | #include <linux/init.h> |
| 21 | #include <linux/bootmem.h> |
| 22 | |
| 23 | #include <asm/setup.h> |
| 24 | #include <asm/uaccess.h> |
| 25 | #include <asm/page.h> |
| 26 | #include <asm/pgalloc.h> |
| 27 | #include <asm/system.h> |
| 28 | #include <asm/machdep.h> |
| 29 | #include <asm/io.h> |
| 30 | #include <asm/dma.h> |
| 31 | #ifdef CONFIG_ATARI |
| 32 | #include <asm/atari_stram.h> |
| 33 | #endif |
| 34 | |
| 35 | #undef DEBUG |
| 36 | |
| 37 | #ifndef mm_cachebits |
| 38 | /* |
| 39 | * Bits to add to page descriptors for "normal" caching mode. |
| 40 | * For 68020/030 this is 0. |
| 41 | * For 68040, this is _PAGE_CACHE040 (cachable, copyback) |
| 42 | */ |
| 43 | unsigned long mm_cachebits; |
| 44 | EXPORT_SYMBOL(mm_cachebits); |
| 45 | #endif |
| 46 | |
| 47 | static pte_t * __init kernel_page_table(void) |
| 48 | { |
| 49 | pte_t *ptablep; |
| 50 | |
| 51 | ptablep = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE); |
| 52 | |
| 53 | clear_page(ptablep); |
| 54 | __flush_page_to_ram(ptablep); |
| 55 | flush_tlb_kernel_page(ptablep); |
| 56 | nocache_page(ptablep); |
| 57 | |
| 58 | return ptablep; |
| 59 | } |
| 60 | |
| 61 | static pmd_t *last_pgtable __initdata = NULL; |
| 62 | pmd_t *zero_pgtable __initdata = NULL; |
| 63 | |
| 64 | static pmd_t * __init kernel_ptr_table(void) |
| 65 | { |
| 66 | if (!last_pgtable) { |
| 67 | unsigned long pmd, last; |
| 68 | int i; |
| 69 | |
| 70 | /* Find the last ptr table that was used in head.S and |
| 71 | * reuse the remaining space in that page for further |
| 72 | * ptr tables. |
| 73 | */ |
| 74 | last = (unsigned long)kernel_pg_dir; |
| 75 | for (i = 0; i < PTRS_PER_PGD; i++) { |
| 76 | if (!pgd_present(kernel_pg_dir[i])) |
| 77 | continue; |
| 78 | pmd = __pgd_page(kernel_pg_dir[i]); |
| 79 | if (pmd > last) |
| 80 | last = pmd; |
| 81 | } |
| 82 | |
| 83 | last_pgtable = (pmd_t *)last; |
| 84 | #ifdef DEBUG |
| 85 | printk("kernel_ptr_init: %p\n", last_pgtable); |
| 86 | #endif |
| 87 | } |
| 88 | |
| 89 | last_pgtable += PTRS_PER_PMD; |
| 90 | if (((unsigned long)last_pgtable & ~PAGE_MASK) == 0) { |
| 91 | last_pgtable = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE); |
| 92 | |
| 93 | clear_page(last_pgtable); |
| 94 | __flush_page_to_ram(last_pgtable); |
| 95 | flush_tlb_kernel_page(last_pgtable); |
| 96 | nocache_page(last_pgtable); |
| 97 | } |
| 98 | |
| 99 | return last_pgtable; |
| 100 | } |
| 101 | |
| 102 | static unsigned long __init |
| 103 | map_chunk (unsigned long addr, long size) |
| 104 | { |
| 105 | #define PTRTREESIZE (256*1024) |
| 106 | #define ROOTTREESIZE (32*1024*1024) |
| 107 | static unsigned long virtaddr = PAGE_OFFSET; |
| 108 | unsigned long physaddr; |
| 109 | pgd_t *pgd_dir; |
| 110 | pmd_t *pmd_dir; |
| 111 | pte_t *pte_dir; |
| 112 | |
| 113 | physaddr = (addr | m68k_supervisor_cachemode | |
| 114 | _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY); |
| 115 | if (CPU_IS_040_OR_060) |
| 116 | physaddr |= _PAGE_GLOBAL040; |
| 117 | |
| 118 | while (size > 0) { |
| 119 | #ifdef DEBUG |
| 120 | if (!(virtaddr & (PTRTREESIZE-1))) |
| 121 | printk ("\npa=%#lx va=%#lx ", physaddr & PAGE_MASK, |
| 122 | virtaddr); |
| 123 | #endif |
| 124 | pgd_dir = pgd_offset_k(virtaddr); |
| 125 | if (virtaddr && CPU_IS_020_OR_030) { |
| 126 | if (!(virtaddr & (ROOTTREESIZE-1)) && |
| 127 | size >= ROOTTREESIZE) { |
| 128 | #ifdef DEBUG |
| 129 | printk ("[very early term]"); |
| 130 | #endif |
| 131 | pgd_val(*pgd_dir) = physaddr; |
| 132 | size -= ROOTTREESIZE; |
| 133 | virtaddr += ROOTTREESIZE; |
| 134 | physaddr += ROOTTREESIZE; |
| 135 | continue; |
| 136 | } |
| 137 | } |
| 138 | if (!pgd_present(*pgd_dir)) { |
| 139 | pmd_dir = kernel_ptr_table(); |
| 140 | #ifdef DEBUG |
| 141 | printk ("[new pointer %p]", pmd_dir); |
| 142 | #endif |
| 143 | pgd_set(pgd_dir, pmd_dir); |
| 144 | } else |
| 145 | pmd_dir = pmd_offset(pgd_dir, virtaddr); |
| 146 | |
| 147 | if (CPU_IS_020_OR_030) { |
| 148 | if (virtaddr) { |
| 149 | #ifdef DEBUG |
| 150 | printk ("[early term]"); |
| 151 | #endif |
| 152 | pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr; |
| 153 | physaddr += PTRTREESIZE; |
| 154 | } else { |
| 155 | int i; |
| 156 | #ifdef DEBUG |
| 157 | printk ("[zero map]"); |
| 158 | #endif |
| 159 | zero_pgtable = kernel_ptr_table(); |
| 160 | pte_dir = (pte_t *)zero_pgtable; |
| 161 | pmd_dir->pmd[0] = virt_to_phys(pte_dir) | |
| 162 | _PAGE_TABLE | _PAGE_ACCESSED; |
| 163 | pte_val(*pte_dir++) = 0; |
| 164 | physaddr += PAGE_SIZE; |
| 165 | for (i = 1; i < 64; physaddr += PAGE_SIZE, i++) |
| 166 | pte_val(*pte_dir++) = physaddr; |
| 167 | } |
| 168 | size -= PTRTREESIZE; |
| 169 | virtaddr += PTRTREESIZE; |
| 170 | } else { |
| 171 | if (!pmd_present(*pmd_dir)) { |
| 172 | #ifdef DEBUG |
| 173 | printk ("[new table]"); |
| 174 | #endif |
| 175 | pte_dir = kernel_page_table(); |
| 176 | pmd_set(pmd_dir, pte_dir); |
| 177 | } |
| 178 | pte_dir = pte_offset_kernel(pmd_dir, virtaddr); |
| 179 | |
| 180 | if (virtaddr) { |
| 181 | if (!pte_present(*pte_dir)) |
| 182 | pte_val(*pte_dir) = physaddr; |
| 183 | } else |
| 184 | pte_val(*pte_dir) = 0; |
| 185 | size -= PAGE_SIZE; |
| 186 | virtaddr += PAGE_SIZE; |
| 187 | physaddr += PAGE_SIZE; |
| 188 | } |
| 189 | |
| 190 | } |
| 191 | #ifdef DEBUG |
| 192 | printk("\n"); |
| 193 | #endif |
| 194 | |
| 195 | return virtaddr; |
| 196 | } |
| 197 | |
| 198 | /* |
| 199 | * paging_init() continues the virtual memory environment setup which |
| 200 | * was begun by the code in arch/head.S. |
| 201 | */ |
| 202 | void __init paging_init(void) |
| 203 | { |
| 204 | int chunk; |
| 205 | unsigned long mem_avail = 0; |
Roman Zippel | 2dcf15b | 2006-06-23 02:04:58 -0700 | [diff] [blame] | 206 | unsigned long zones_size[MAX_NR_ZONES] = { 0, }; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | |
| 208 | #ifdef DEBUG |
| 209 | { |
| 210 | extern unsigned long availmem; |
| 211 | printk ("start of paging_init (%p, %lx, %lx, %lx)\n", |
| 212 | kernel_pg_dir, availmem, start_mem, end_mem); |
| 213 | } |
| 214 | #endif |
| 215 | |
| 216 | /* Fix the cache mode in the page descriptors for the 680[46]0. */ |
| 217 | if (CPU_IS_040_OR_060) { |
| 218 | int i; |
| 219 | #ifndef mm_cachebits |
| 220 | mm_cachebits = _PAGE_CACHE040; |
| 221 | #endif |
| 222 | for (i = 0; i < 16; i++) |
| 223 | pgprot_val(protection_map[i]) |= _PAGE_CACHE040; |
| 224 | } |
| 225 | |
| 226 | /* |
| 227 | * Map the physical memory available into the kernel virtual |
| 228 | * address space. It may allocate some memory for page |
| 229 | * tables and thus modify availmem. |
| 230 | */ |
| 231 | |
| 232 | for (chunk = 0; chunk < m68k_num_memory; chunk++) { |
| 233 | mem_avail = map_chunk (m68k_memory[chunk].addr, |
| 234 | m68k_memory[chunk].size); |
| 235 | |
| 236 | } |
| 237 | |
| 238 | flush_tlb_all(); |
| 239 | #ifdef DEBUG |
| 240 | printk ("memory available is %ldKB\n", mem_avail >> 10); |
| 241 | printk ("start_mem is %#lx\nvirtual_end is %#lx\n", |
| 242 | start_mem, end_mem); |
| 243 | #endif |
| 244 | |
| 245 | /* |
| 246 | * initialize the bad page table and bad page to point |
| 247 | * to a couple of allocated pages |
| 248 | */ |
| 249 | empty_zero_page = alloc_bootmem_pages(PAGE_SIZE); |
| 250 | memset(empty_zero_page, 0, PAGE_SIZE); |
| 251 | |
| 252 | /* |
| 253 | * Set up SFC/DFC registers |
| 254 | */ |
| 255 | set_fs(KERNEL_DS); |
| 256 | |
| 257 | #ifdef DEBUG |
| 258 | printk ("before free_area_init\n"); |
| 259 | #endif |
Roman Zippel | 2dcf15b | 2006-06-23 02:04:58 -0700 | [diff] [blame] | 260 | zones_size[ZONE_DMA] = (mach_max_dma_address < (unsigned long)high_memory ? |
| 261 | (mach_max_dma_address+1) : (unsigned long)high_memory); |
| 262 | zones_size[ZONE_NORMAL] = (unsigned long)high_memory - zones_size[0]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 263 | |
Roman Zippel | 2dcf15b | 2006-06-23 02:04:58 -0700 | [diff] [blame] | 264 | zones_size[ZONE_DMA] = (zones_size[ZONE_DMA] - PAGE_OFFSET) >> PAGE_SHIFT; |
| 265 | zones_size[ZONE_NORMAL] >>= PAGE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 266 | |
| 267 | free_area_init(zones_size); |
| 268 | } |
| 269 | |
| 270 | extern char __init_begin, __init_end; |
| 271 | |
| 272 | void free_initmem(void) |
| 273 | { |
| 274 | unsigned long addr; |
| 275 | |
| 276 | addr = (unsigned long)&__init_begin; |
| 277 | for (; addr < (unsigned long)&__init_end; addr += PAGE_SIZE) { |
| 278 | virt_to_page(addr)->flags &= ~(1 << PG_reserved); |
Nick Piggin | 7835e98 | 2006-03-22 00:08:40 -0800 | [diff] [blame] | 279 | init_page_count(virt_to_page(addr)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 280 | free_page(addr); |
| 281 | totalram_pages++; |
| 282 | } |
| 283 | } |
| 284 | |
| 285 | |