motorola.c 7.3 KB
Newer Older
L
Linus Torvalds 已提交
1
/*
2
 * linux/arch/m68k/mm/motorola.c
L
Linus Torvalds 已提交
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
 *
 * Routines specific to the Motorola MMU, originally from:
 * linux/arch/m68k/init.c
 * which are Copyright (C) 1995 Hamish Macdonald
 *
 * Moved 8/20/1999 Sam Creasey
 */

#include <linux/module.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/bootmem.h>
21
#include <linux/gfp.h>
L
Linus Torvalds 已提交
22 23 24 25 26 27 28 29 30 31 32

#include <asm/setup.h>
#include <asm/uaccess.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/machdep.h>
#include <asm/io.h>
#include <asm/dma.h>
#ifdef CONFIG_ATARI
#include <asm/atari_stram.h>
#endif
33
#include <asm/sections.h>
L
Linus Torvalds 已提交
34 35 36 37 38 39 40 41 42 43 44 45 46

#undef DEBUG

#ifndef mm_cachebits
/*
 * Bits to add to page descriptors for "normal" caching mode.
 * For 68020/030 this is 0.
 * For 68040, this is _PAGE_CACHE040 (cachable, copyback)
 */
unsigned long mm_cachebits;
EXPORT_SYMBOL(mm_cachebits);
#endif

47 48 49 50 51
/* size of memory already mapped in head.S */
#define INIT_MAPPED_SIZE	(4UL<<20)

extern unsigned long availmem;

L
Linus Torvalds 已提交
52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106
static pte_t * __init kernel_page_table(void)
{
	pte_t *ptablep;

	ptablep = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);

	clear_page(ptablep);
	__flush_page_to_ram(ptablep);
	flush_tlb_kernel_page(ptablep);
	nocache_page(ptablep);

	return ptablep;
}

static pmd_t *last_pgtable __initdata = NULL;
pmd_t *zero_pgtable __initdata = NULL;

static pmd_t * __init kernel_ptr_table(void)
{
	if (!last_pgtable) {
		unsigned long pmd, last;
		int i;

		/* Find the last ptr table that was used in head.S and
		 * reuse the remaining space in that page for further
		 * ptr tables.
		 */
		last = (unsigned long)kernel_pg_dir;
		for (i = 0; i < PTRS_PER_PGD; i++) {
			if (!pgd_present(kernel_pg_dir[i]))
				continue;
			pmd = __pgd_page(kernel_pg_dir[i]);
			if (pmd > last)
				last = pmd;
		}

		last_pgtable = (pmd_t *)last;
#ifdef DEBUG
		printk("kernel_ptr_init: %p\n", last_pgtable);
#endif
	}

	last_pgtable += PTRS_PER_PMD;
	if (((unsigned long)last_pgtable & ~PAGE_MASK) == 0) {
		last_pgtable = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);

		clear_page(last_pgtable);
		__flush_page_to_ram(last_pgtable);
		flush_tlb_kernel_page(last_pgtable);
		nocache_page(last_pgtable);
	}

	return last_pgtable;
}

107
static void __init map_node(int node)
L
Linus Torvalds 已提交
108 109 110
{
#define PTRTREESIZE (256*1024)
#define ROOTTREESIZE (32*1024*1024)
111
	unsigned long physaddr, virtaddr, size;
L
Linus Torvalds 已提交
112 113 114 115
	pgd_t *pgd_dir;
	pmd_t *pmd_dir;
	pte_t *pte_dir;

116 117 118 119 120
	size = m68k_memory[node].size;
	physaddr = m68k_memory[node].addr;
	virtaddr = (unsigned long)phys_to_virt(physaddr);
	physaddr |= m68k_supervisor_cachemode |
		    _PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY;
L
Linus Torvalds 已提交
121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207
	if (CPU_IS_040_OR_060)
		physaddr |= _PAGE_GLOBAL040;

	while (size > 0) {
#ifdef DEBUG
		if (!(virtaddr & (PTRTREESIZE-1)))
			printk ("\npa=%#lx va=%#lx ", physaddr & PAGE_MASK,
				virtaddr);
#endif
		pgd_dir = pgd_offset_k(virtaddr);
		if (virtaddr && CPU_IS_020_OR_030) {
			if (!(virtaddr & (ROOTTREESIZE-1)) &&
			    size >= ROOTTREESIZE) {
#ifdef DEBUG
				printk ("[very early term]");
#endif
				pgd_val(*pgd_dir) = physaddr;
				size -= ROOTTREESIZE;
				virtaddr += ROOTTREESIZE;
				physaddr += ROOTTREESIZE;
				continue;
			}
		}
		if (!pgd_present(*pgd_dir)) {
			pmd_dir = kernel_ptr_table();
#ifdef DEBUG
			printk ("[new pointer %p]", pmd_dir);
#endif
			pgd_set(pgd_dir, pmd_dir);
		} else
			pmd_dir = pmd_offset(pgd_dir, virtaddr);

		if (CPU_IS_020_OR_030) {
			if (virtaddr) {
#ifdef DEBUG
				printk ("[early term]");
#endif
				pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
				physaddr += PTRTREESIZE;
			} else {
				int i;
#ifdef DEBUG
				printk ("[zero map]");
#endif
				zero_pgtable = kernel_ptr_table();
				pte_dir = (pte_t *)zero_pgtable;
				pmd_dir->pmd[0] = virt_to_phys(pte_dir) |
					_PAGE_TABLE | _PAGE_ACCESSED;
				pte_val(*pte_dir++) = 0;
				physaddr += PAGE_SIZE;
				for (i = 1; i < 64; physaddr += PAGE_SIZE, i++)
					pte_val(*pte_dir++) = physaddr;
			}
			size -= PTRTREESIZE;
			virtaddr += PTRTREESIZE;
		} else {
			if (!pmd_present(*pmd_dir)) {
#ifdef DEBUG
				printk ("[new table]");
#endif
				pte_dir = kernel_page_table();
				pmd_set(pmd_dir, pte_dir);
			}
			pte_dir = pte_offset_kernel(pmd_dir, virtaddr);

			if (virtaddr) {
				if (!pte_present(*pte_dir))
					pte_val(*pte_dir) = physaddr;
			} else
				pte_val(*pte_dir) = 0;
			size -= PAGE_SIZE;
			virtaddr += PAGE_SIZE;
			physaddr += PAGE_SIZE;
		}

	}
#ifdef DEBUG
	printk("\n");
#endif
}

/*
 * paging_init() continues the virtual memory environment setup which
 * was begun by the code in arch/head.S.
 */
void __init paging_init(void)
{
208
	unsigned long zones_size[MAX_NR_ZONES] = { 0, };
209 210 211
	unsigned long min_addr, max_addr;
	unsigned long addr, size, end;
	int i;
L
Linus Torvalds 已提交
212 213

#ifdef DEBUG
214
	printk ("start of paging_init (%p, %lx)\n", kernel_pg_dir, availmem);
L
Linus Torvalds 已提交
215 216 217 218 219 220 221 222 223 224 225 226
#endif

	/* Fix the cache mode in the page descriptors for the 680[46]0.  */
	if (CPU_IS_040_OR_060) {
		int i;
#ifndef mm_cachebits
		mm_cachebits = _PAGE_CACHE040;
#endif
		for (i = 0; i < 16; i++)
			pgprot_val(protection_map[i]) |= _PAGE_CACHE040;
	}

227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246
	min_addr = m68k_memory[0].addr;
	max_addr = min_addr + m68k_memory[0].size;
	for (i = 1; i < m68k_num_memory;) {
		if (m68k_memory[i].addr < min_addr) {
			printk("Ignoring memory chunk at 0x%lx:0x%lx before the first chunk\n",
				m68k_memory[i].addr, m68k_memory[i].size);
			printk("Fix your bootloader or use a memfile to make use of this area!\n");
			m68k_num_memory--;
			memmove(m68k_memory + i, m68k_memory + i + 1,
				(m68k_num_memory - i) * sizeof(struct mem_info));
			continue;
		}
		addr = m68k_memory[i].addr + m68k_memory[i].size;
		if (addr > max_addr)
			max_addr = addr;
		i++;
	}
	m68k_memoffset = min_addr - PAGE_OFFSET;
	m68k_virt_to_node_shift = fls(max_addr - min_addr - 1) - 6;

247 248 249
	module_fixup(NULL, __start_fixup, __stop_fixup);
	flush_icache();

250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265
	high_memory = phys_to_virt(max_addr);

	min_low_pfn = availmem >> PAGE_SHIFT;
	max_low_pfn = max_addr >> PAGE_SHIFT;

	for (i = 0; i < m68k_num_memory; i++) {
		addr = m68k_memory[i].addr;
		end = addr + m68k_memory[i].size;
		m68k_setup_node(i);
		availmem = PAGE_ALIGN(availmem);
		availmem += init_bootmem_node(NODE_DATA(i),
					      availmem >> PAGE_SHIFT,
					      addr >> PAGE_SHIFT,
					      end >> PAGE_SHIFT);
	}

L
Linus Torvalds 已提交
266 267
	/*
	 * Map the physical memory available into the kernel virtual
268 269 270
	 * address space. First initialize the bootmem allocator with
	 * the memory we already mapped, so map_node() has something
	 * to allocate.
L
Linus Torvalds 已提交
271
	 */
272 273 274 275 276 277
	addr = m68k_memory[0].addr;
	size = m68k_memory[0].size;
	free_bootmem_node(NODE_DATA(0), availmem, min(INIT_MAPPED_SIZE, size) - (availmem - addr));
	map_node(0);
	if (size > INIT_MAPPED_SIZE)
		free_bootmem_node(NODE_DATA(0), addr + INIT_MAPPED_SIZE, size - INIT_MAPPED_SIZE);
L
Linus Torvalds 已提交
278

279 280
	for (i = 1; i < m68k_num_memory; i++)
		map_node(i);
L
Linus Torvalds 已提交
281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297

	flush_tlb_all();

	/*
	 * initialize the bad page table and bad page to point
	 * to a couple of allocated pages
	 */
	empty_zero_page = alloc_bootmem_pages(PAGE_SIZE);

	/*
	 * Set up SFC/DFC registers
	 */
	set_fs(KERNEL_DS);

#ifdef DEBUG
	printk ("before free_area_init\n");
#endif
298 299
	for (i = 0; i < m68k_num_memory; i++) {
		zones_size[ZONE_DMA] = m68k_memory[i].size >> PAGE_SHIFT;
300
		free_area_init_node(i, zones_size,
301
				    m68k_memory[i].addr >> PAGE_SHIFT, NULL);
302 303
		if (node_present_pages(i))
			node_set_state(i, N_NORMAL_MEMORY);
304
	}
L
Linus Torvalds 已提交
305 306
}