1 /* 2 * linux/arch/m68k/mm/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/module.h> 12 #include <linux/signal.h> 13 #include <linux/sched.h> 14 #include <linux/mm.h> 15 #include <linux/swap.h> 16 #include <linux/kernel.h> 17 #include <linux/string.h> 18 #include <linux/types.h> 19 #include <linux/init.h> 20 #include <linux/bootmem.h> 21 22 #include <asm/setup.h> 23 #include <asm/uaccess.h> 24 #include <asm/page.h> 25 #include <asm/pgalloc.h> 26 #include <asm/system.h> 27 #include <asm/machdep.h> 28 #include <asm/io.h> 29 #include <asm/dma.h> 30 #ifdef CONFIG_ATARI 31 #include <asm/atari_stram.h> 32 #endif 33 34 #undef DEBUG 35 36 #ifndef mm_cachebits 37 /* 38 * Bits to add to page descriptors for "normal" caching mode. 39 * For 68020/030 this is 0. 40 * For 68040, this is _PAGE_CACHE040 (cachable, copyback) 41 */ 42 unsigned long mm_cachebits; 43 EXPORT_SYMBOL(mm_cachebits); 44 #endif 45 46 /* size of memory already mapped in head.S */ 47 #define INIT_MAPPED_SIZE (4UL<<20) 48 49 extern unsigned long availmem; 50 51 static pte_t * __init kernel_page_table(void) 52 { 53 pte_t *ptablep; 54 55 ptablep = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE); 56 57 clear_page(ptablep); 58 __flush_page_to_ram(ptablep); 59 flush_tlb_kernel_page(ptablep); 60 nocache_page(ptablep); 61 62 return ptablep; 63 } 64 65 static pmd_t *last_pgtable __initdata = NULL; 66 pmd_t *zero_pgtable __initdata = NULL; 67 68 static pmd_t * __init kernel_ptr_table(void) 69 { 70 if (!last_pgtable) { 71 unsigned long pmd, last; 72 int i; 73 74 /* Find the last ptr table that was used in head.S and 75 * reuse the remaining space in that page for further 76 * ptr tables. 77 */ 78 last = (unsigned long)kernel_pg_dir; 79 for (i = 0; i < PTRS_PER_PGD; i++) { 80 if (!pgd_present(kernel_pg_dir[i])) 81 continue; 82 pmd = __pgd_page(kernel_pg_dir[i]); 83 if (pmd > last) 84 last = pmd; 85 } 86 87 last_pgtable = (pmd_t *)last; 88 #ifdef DEBUG 89 printk("kernel_ptr_init: %p\n", last_pgtable); 90 #endif 91 } 92 93 last_pgtable += PTRS_PER_PMD; 94 if (((unsigned long)last_pgtable & ~PAGE_MASK) == 0) { 95 last_pgtable = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE); 96 97 clear_page(last_pgtable); 98 __flush_page_to_ram(last_pgtable); 99 flush_tlb_kernel_page(last_pgtable); 100 nocache_page(last_pgtable); 101 } 102 103 return last_pgtable; 104 } 105 106 static void __init map_node(int node) 107 { 108 #define PTRTREESIZE (256*1024) 109 #define ROOTTREESIZE (32*1024*1024) 110 unsigned long physaddr, virtaddr, size; 111 pgd_t *pgd_dir; 112 pmd_t *pmd_dir; 113 pte_t *pte_dir; 114 115 size = m68k_memory[node].size; 116 physaddr = m68k_memory[node].addr; 117 virtaddr = (unsigned long)phys_to_virt(physaddr); 118 physaddr |= m68k_supervisor_cachemode | 119 _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY; 120 if (CPU_IS_040_OR_060) 121 physaddr |= _PAGE_GLOBAL040; 122 123 while (size > 0) { 124 #ifdef DEBUG 125 if (!(virtaddr & (PTRTREESIZE-1))) 126 printk ("\npa=%#lx va=%#lx ", physaddr & PAGE_MASK, 127 virtaddr); 128 #endif 129 pgd_dir = pgd_offset_k(virtaddr); 130 if (virtaddr && CPU_IS_020_OR_030) { 131 if (!(virtaddr & (ROOTTREESIZE-1)) && 132 size >= ROOTTREESIZE) { 133 #ifdef DEBUG 134 printk ("[very early term]"); 135 #endif 136 pgd_val(*pgd_dir) = physaddr; 137 size -= ROOTTREESIZE; 138 virtaddr += ROOTTREESIZE; 139 physaddr += ROOTTREESIZE; 140 continue; 141 } 142 } 143 if (!pgd_present(*pgd_dir)) { 144 pmd_dir = kernel_ptr_table(); 145 #ifdef DEBUG 146 printk ("[new pointer %p]", pmd_dir); 147 #endif 148 pgd_set(pgd_dir, pmd_dir); 149 } else 150 pmd_dir = pmd_offset(pgd_dir, virtaddr); 151 152 if (CPU_IS_020_OR_030) { 153 if (virtaddr) { 154 #ifdef DEBUG 155 printk ("[early term]"); 156 #endif 157 pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr; 158 physaddr += PTRTREESIZE; 159 } else { 160 int i; 161 #ifdef DEBUG 162 printk ("[zero map]"); 163 #endif 164 zero_pgtable = kernel_ptr_table(); 165 pte_dir = (pte_t *)zero_pgtable; 166 pmd_dir->pmd[0] = virt_to_phys(pte_dir) | 167 _PAGE_TABLE | _PAGE_ACCESSED; 168 pte_val(*pte_dir++) = 0; 169 physaddr += PAGE_SIZE; 170 for (i = 1; i < 64; physaddr += PAGE_SIZE, i++) 171 pte_val(*pte_dir++) = physaddr; 172 } 173 size -= PTRTREESIZE; 174 virtaddr += PTRTREESIZE; 175 } else { 176 if (!pmd_present(*pmd_dir)) { 177 #ifdef DEBUG 178 printk ("[new table]"); 179 #endif 180 pte_dir = kernel_page_table(); 181 pmd_set(pmd_dir, pte_dir); 182 } 183 pte_dir = pte_offset_kernel(pmd_dir, virtaddr); 184 185 if (virtaddr) { 186 if (!pte_present(*pte_dir)) 187 pte_val(*pte_dir) = physaddr; 188 } else 189 pte_val(*pte_dir) = 0; 190 size -= PAGE_SIZE; 191 virtaddr += PAGE_SIZE; 192 physaddr += PAGE_SIZE; 193 } 194 195 } 196 #ifdef DEBUG 197 printk("\n"); 198 #endif 199 } 200 201 /* 202 * paging_init() continues the virtual memory environment setup which 203 * was begun by the code in arch/head.S. 204 */ 205 void __init paging_init(void) 206 { 207 unsigned long zones_size[MAX_NR_ZONES] = { 0, }; 208 unsigned long min_addr, max_addr; 209 unsigned long addr, size, end; 210 int i; 211 212 #ifdef DEBUG 213 printk ("start of paging_init (%p, %lx)\n", kernel_pg_dir, availmem); 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 min_addr = m68k_memory[0].addr; 227 max_addr = min_addr + m68k_memory[0].size; 228 for (i = 1; i < m68k_num_memory;) { 229 if (m68k_memory[i].addr < min_addr) { 230 printk("Ignoring memory chunk at 0x%lx:0x%lx before the first chunk\n", 231 m68k_memory[i].addr, m68k_memory[i].size); 232 printk("Fix your bootloader or use a memfile to make use of this area!\n"); 233 m68k_num_memory--; 234 memmove(m68k_memory + i, m68k_memory + i + 1, 235 (m68k_num_memory - i) * sizeof(struct mem_info)); 236 continue; 237 } 238 addr = m68k_memory[i].addr + m68k_memory[i].size; 239 if (addr > max_addr) 240 max_addr = addr; 241 i++; 242 } 243 m68k_memoffset = min_addr - PAGE_OFFSET; 244 m68k_virt_to_node_shift = fls(max_addr - min_addr - 1) - 6; 245 246 module_fixup(NULL, __start_fixup, __stop_fixup); 247 flush_icache(); 248 249 high_memory = phys_to_virt(max_addr); 250 251 min_low_pfn = availmem >> PAGE_SHIFT; 252 max_low_pfn = max_addr >> PAGE_SHIFT; 253 254 for (i = 0; i < m68k_num_memory; i++) { 255 addr = m68k_memory[i].addr; 256 end = addr + m68k_memory[i].size; 257 m68k_setup_node(i); 258 availmem = PAGE_ALIGN(availmem); 259 availmem += init_bootmem_node(NODE_DATA(i), 260 availmem >> PAGE_SHIFT, 261 addr >> PAGE_SHIFT, 262 end >> PAGE_SHIFT); 263 } 264 265 /* 266 * Map the physical memory available into the kernel virtual 267 * address space. First initialize the bootmem allocator with 268 * the memory we already mapped, so map_node() has something 269 * to allocate. 270 */ 271 addr = m68k_memory[0].addr; 272 size = m68k_memory[0].size; 273 free_bootmem_node(NODE_DATA(0), availmem, min(INIT_MAPPED_SIZE, size) - (availmem - addr)); 274 map_node(0); 275 if (size > INIT_MAPPED_SIZE) 276 free_bootmem_node(NODE_DATA(0), addr + INIT_MAPPED_SIZE, size - INIT_MAPPED_SIZE); 277 278 for (i = 1; i < m68k_num_memory; i++) 279 map_node(i); 280 281 flush_tlb_all(); 282 283 /* 284 * initialize the bad page table and bad page to point 285 * to a couple of allocated pages 286 */ 287 empty_zero_page = alloc_bootmem_pages(PAGE_SIZE); 288 289 /* 290 * Set up SFC/DFC registers 291 */ 292 set_fs(KERNEL_DS); 293 294 #ifdef DEBUG 295 printk ("before free_area_init\n"); 296 #endif 297 for (i = 0; i < m68k_num_memory; i++) { 298 zones_size[ZONE_DMA] = m68k_memory[i].size >> PAGE_SHIFT; 299 free_area_init_node(i, zones_size, 300 m68k_memory[i].addr >> PAGE_SHIFT, NULL); 301 } 302 } 303 304 extern char __init_begin, __init_end; 305 306 void free_initmem(void) 307 { 308 unsigned long addr; 309 310 addr = (unsigned long)&__init_begin; 311 for (; addr < (unsigned long)&__init_end; addr += PAGE_SIZE) { 312 virt_to_page(addr)->flags &= ~(1 << PG_reserved); 313 init_page_count(virt_to_page(addr)); 314 free_page(addr); 315 totalram_pages++; 316 } 317 } 318 319 320