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#include <linux/gfp.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#include <asm/sections.h> 35 36#undef DEBUG 37 38#ifndef mm_cachebits 39/* 40 * Bits to add to page descriptors for "normal" caching mode. 41 * For 68020/030 this is 0. 42 * For 68040, this is _PAGE_CACHE040 (cachable, copyback) 43 */ 44unsigned long mm_cachebits; 45EXPORT_SYMBOL(mm_cachebits); 46#endif 47 48/* size of memory already mapped in head.S */ 49#define INIT_MAPPED_SIZE (4UL<<20) 50 51extern unsigned long availmem; 52 53static pte_t * __init kernel_page_table(void) 54{ 55 pte_t *ptablep; 56 57 ptablep = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE); 58 59 clear_page(ptablep); 60 __flush_page_to_ram(ptablep); 61 flush_tlb_kernel_page(ptablep); 62 nocache_page(ptablep); 63 64 return ptablep; 65} 66 67static pmd_t *last_pgtable __initdata = NULL; 68pmd_t *zero_pgtable __initdata = NULL; 69 70static pmd_t * __init kernel_ptr_table(void) 71{ 72 if (!last_pgtable) { 73 unsigned long pmd, last; 74 int i; 75 76 /* Find the last ptr table that was used in head.S and 77 * reuse the remaining space in that page for further 78 * ptr tables. 79 */ 80 last = (unsigned long)kernel_pg_dir; 81 for (i = 0; i < PTRS_PER_PGD; i++) { 82 if (!pgd_present(kernel_pg_dir[i])) 83 continue; 84 pmd = __pgd_page(kernel_pg_dir[i]); 85 if (pmd > last) 86 last = pmd; 87 } 88 89 last_pgtable = (pmd_t *)last; 90#ifdef DEBUG 91 printk("kernel_ptr_init: %p\n", last_pgtable); 92#endif 93 } 94 95 last_pgtable += PTRS_PER_PMD; 96 if (((unsigned long)last_pgtable & ~PAGE_MASK) == 0) { 97 last_pgtable = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE); 98 99 clear_page(last_pgtable); 100 __flush_page_to_ram(last_pgtable); 101 flush_tlb_kernel_page(last_pgtable); 102 nocache_page(last_pgtable); 103 } 104 105 return last_pgtable; 106} 107 108static void __init map_node(int node) 109{ 110#define PTRTREESIZE (256*1024) 111#define ROOTTREESIZE (32*1024*1024) 112 unsigned long physaddr, virtaddr, size; 113 pgd_t *pgd_dir; 114 pmd_t *pmd_dir; 115 pte_t *pte_dir; 116 117 size = m68k_memory[node].size; 118 physaddr = m68k_memory[node].addr; 119 virtaddr = (unsigned long)phys_to_virt(physaddr); 120 physaddr |= m68k_supervisor_cachemode | 121 _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY; 122 if (CPU_IS_040_OR_060) 123 physaddr |= _PAGE_GLOBAL040; 124 125 while (size > 0) { 126#ifdef DEBUG 127 if (!(virtaddr & (PTRTREESIZE-1))) 128 printk ("\npa=%#lx va=%#lx ", physaddr & PAGE_MASK, 129 virtaddr); 130#endif 131 pgd_dir = pgd_offset_k(virtaddr); 132 if (virtaddr && CPU_IS_020_OR_030) { 133 if (!(virtaddr & (ROOTTREESIZE-1)) && 134 size >= ROOTTREESIZE) { 135#ifdef DEBUG 136 printk ("[very early term]"); 137#endif 138 pgd_val(*pgd_dir) = physaddr; 139 size -= ROOTTREESIZE; 140 virtaddr += ROOTTREESIZE; 141 physaddr += ROOTTREESIZE; 142 continue; 143 } 144 } 145 if (!pgd_present(*pgd_dir)) { 146 pmd_dir = kernel_ptr_table(); 147#ifdef DEBUG 148 printk ("[new pointer %p]", pmd_dir); 149#endif 150 pgd_set(pgd_dir, pmd_dir); 151 } else 152 pmd_dir = pmd_offset(pgd_dir, virtaddr); 153 154 if (CPU_IS_020_OR_030) { 155 if (virtaddr) { 156#ifdef DEBUG 157 printk ("[early term]"); 158#endif 159 pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr; 160 physaddr += PTRTREESIZE; 161 } else { 162 int i; 163#ifdef DEBUG 164 printk ("[zero map]"); 165#endif 166 zero_pgtable = kernel_ptr_table(); 167 pte_dir = (pte_t *)zero_pgtable; 168 pmd_dir->pmd[0] = virt_to_phys(pte_dir) | 169 _PAGE_TABLE | _PAGE_ACCESSED; 170 pte_val(*pte_dir++) = 0; 171 physaddr += PAGE_SIZE; 172 for (i = 1; i < 64; physaddr += PAGE_SIZE, i++) 173 pte_val(*pte_dir++) = physaddr; 174 } 175 size -= PTRTREESIZE; 176 virtaddr += PTRTREESIZE; 177 } else { 178 if (!pmd_present(*pmd_dir)) { 179#ifdef DEBUG 180 printk ("[new table]"); 181#endif 182 pte_dir = kernel_page_table(); 183 pmd_set(pmd_dir, pte_dir); 184 } 185 pte_dir = pte_offset_kernel(pmd_dir, virtaddr); 186 187 if (virtaddr) { 188 if (!pte_present(*pte_dir)) 189 pte_val(*pte_dir) = physaddr; 190 } else 191 pte_val(*pte_dir) = 0; 192 size -= PAGE_SIZE; 193 virtaddr += PAGE_SIZE; 194 physaddr += PAGE_SIZE; 195 } 196 197 } 198#ifdef DEBUG 199 printk("\n"); 200#endif 201} 202 203/* 204 * paging_init() continues the virtual memory environment setup which 205 * was begun by the code in arch/head.S. 206 */ 207void __init paging_init(void) 208{ 209 unsigned long zones_size[MAX_NR_ZONES] = { 0, }; 210 unsigned long min_addr, max_addr; 211 unsigned long addr, size, end; 212 int i; 213 214#ifdef DEBUG 215 printk ("start of paging_init (%p, %lx)\n", kernel_pg_dir, availmem); 216#endif 217 218 /* Fix the cache mode in the page descriptors for the 680[46]0. */ 219 if (CPU_IS_040_OR_060) { 220 int i; 221#ifndef mm_cachebits 222 mm_cachebits = _PAGE_CACHE040; 223#endif 224 for (i = 0; i < 16; i++) 225 pgprot_val(protection_map[i]) |= _PAGE_CACHE040; 226 } 227 228 min_addr = m68k_memory[0].addr; 229 max_addr = min_addr + m68k_memory[0].size; 230 for (i = 1; i < m68k_num_memory;) { 231 if (m68k_memory[i].addr < min_addr) { 232 printk("Ignoring memory chunk at 0x%lx:0x%lx before the first chunk\n", 233 m68k_memory[i].addr, m68k_memory[i].size); 234 printk("Fix your bootloader or use a memfile to make use of this area!\n"); 235 m68k_num_memory--; 236 memmove(m68k_memory + i, m68k_memory + i + 1, 237 (m68k_num_memory - i) * sizeof(struct mem_info)); 238 continue; 239 } 240 addr = m68k_memory[i].addr + m68k_memory[i].size; 241 if (addr > max_addr) 242 max_addr = addr; 243 i++; 244 } 245 m68k_memoffset = min_addr - PAGE_OFFSET; 246 m68k_virt_to_node_shift = fls(max_addr - min_addr - 1) - 6; 247 248 module_fixup(NULL, __start_fixup, __stop_fixup); 249 flush_icache(); 250 251 high_memory = phys_to_virt(max_addr); 252 253 min_low_pfn = availmem >> PAGE_SHIFT; 254 max_low_pfn = max_addr >> PAGE_SHIFT; 255 256 for (i = 0; i < m68k_num_memory; i++) { 257 addr = m68k_memory[i].addr; 258 end = addr + m68k_memory[i].size; 259 m68k_setup_node(i); 260 availmem = PAGE_ALIGN(availmem); 261 availmem += init_bootmem_node(NODE_DATA(i), 262 availmem >> PAGE_SHIFT, 263 addr >> PAGE_SHIFT, 264 end >> PAGE_SHIFT); 265 } 266 267 /* 268 * Map the physical memory available into the kernel virtual 269 * address space. First initialize the bootmem allocator with 270 * the memory we already mapped, so map_node() has something 271 * to allocate. 272 */ 273 addr = m68k_memory[0].addr; 274 size = m68k_memory[0].size; 275 free_bootmem_node(NODE_DATA(0), availmem, min(INIT_MAPPED_SIZE, size) - (availmem - addr)); 276 map_node(0); 277 if (size > INIT_MAPPED_SIZE) 278 free_bootmem_node(NODE_DATA(0), addr + INIT_MAPPED_SIZE, size - INIT_MAPPED_SIZE); 279 280 for (i = 1; i < m68k_num_memory; i++) 281 map_node(i); 282 283 flush_tlb_all(); 284 285 /* 286 * initialize the bad page table and bad page to point 287 * to a couple of allocated pages 288 */ 289 empty_zero_page = alloc_bootmem_pages(PAGE_SIZE); 290 291 /* 292 * Set up SFC/DFC registers 293 */ 294 set_fs(KERNEL_DS); 295 296#ifdef DEBUG 297 printk ("before free_area_init\n"); 298#endif 299 for (i = 0; i < m68k_num_memory; i++) { 300 zones_size[ZONE_DMA] = m68k_memory[i].size >> PAGE_SHIFT; 301 free_area_init_node(i, zones_size, 302 m68k_memory[i].addr >> PAGE_SHIFT, NULL); 303 } 304} 305 306void 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