init.c

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unsigned long last_valid_pfn;

void __init paging_init(void)
{
	switch(sparc_cpu_model) {
	case sun4c:
	case sun4e:
	case sun4:
		sun4c_paging_init();
		sparc_unmapped_base = 0xe0000000;
		BTFIXUPSET_SETHI(sparc_unmapped_base, 0xe0000000);
		break;
	case sun4m:
	case sun4d:
		srmmu_paging_init();
		sparc_unmapped_base = 0x50000000;
		BTFIXUPSET_SETHI(sparc_unmapped_base, 0x50000000);
		break;
	default:
		prom_printf("paging_init: Cannot init paging on this Sparc\n");
		prom_printf("paging_init: sparc_cpu_model = %d\n", sparc_cpu_model);
		prom_printf("paging_init: Halting...\n");
		prom_halt();
	};

	/* Initialize the protection map with non-constant, MMU dependent values. */
	protection_map[0] = PAGE_NONE;
	protection_map[1] = PAGE_READONLY;
	protection_map[2] = PAGE_COPY;
	protection_map[3] = PAGE_COPY;
	protection_map[4] = PAGE_READONLY;
	protection_map[5] = PAGE_READONLY;
	protection_map[6] = PAGE_COPY;
	protection_map[7] = PAGE_COPY;
	protection_map[8] = PAGE_NONE;
	protection_map[9] = PAGE_READONLY;
	protection_map[10] = PAGE_SHARED;
	protection_map[11] = PAGE_SHARED;
	protection_map[12] = PAGE_READONLY;
	protection_map[13] = PAGE_READONLY;
	protection_map[14] = PAGE_SHARED;
	protection_map[15] = PAGE_SHARED;
	btfixup();
	device_scan();
}

struct cache_palias *sparc_aliases;

static void __init taint_real_pages(void)
{
	int i;

	for (i = 0; sp_banks[i].num_bytes; i++) {
		unsigned long start, end;

		start = sp_banks[i].base_addr;
		end = start + sp_banks[i].num_bytes;

		while (start < end) {
			set_bit (start >> 20,
				sparc_valid_addr_bitmap);
				start += PAGE_SIZE;
		}
	}
}

void __init free_mem_map_range(struct page *first, struct page *last)
{
	first = (struct page *) PAGE_ALIGN((unsigned long)first);
	last  = (struct page *) ((unsigned long)last & PAGE_MASK);
#ifdef DEBUG_BOOTMEM
	prom_printf("[%p,%p] ", first, last);
#endif
	while (first < last) {
		ClearPageReserved(virt_to_page(first));
		set_page_count(virt_to_page(first), 1);
		free_page((unsigned long)first);
		totalram_pages++;
		num_physpages++;

		first = (struct page *)((unsigned long)first + PAGE_SIZE);
	}
}

/* Walk through holes in sp_banks regions, if the mem_map array
 * areas representing those holes consume a page or more, free
 * up such pages.  This helps a lot on machines where physical
 * ram is configured such that it begins at some hugh value.
 *
 * The sp_banks array is sorted by base address.
 */
void __init free_unused_mem_map(void)
{
	int i;

#ifdef DEBUG_BOOTMEM
	prom_printf("free_unused_mem_map: ");
#endif
	for (i = 0; sp_banks[i].num_bytes; i++) {
		if (i == 0) {
			struct page *first, *last;

			first = mem_map;
			last = &mem_map[sp_banks[i].base_addr >> PAGE_SHIFT];
			free_mem_map_range(first, last);
		} else {
			struct page *first, *last;
			unsigned long prev_end;

			prev_end = sp_banks[i-1].base_addr +
				sp_banks[i-1].num_bytes;
			prev_end = PAGE_ALIGN(prev_end);
			first = &mem_map[prev_end >> PAGE_SHIFT];
			last = &mem_map[sp_banks[i].base_addr >> PAGE_SHIFT];

			free_mem_map_range(first, last);

			if (!sp_banks[i+1].num_bytes) {
				prev_end = sp_banks[i].base_addr +
					sp_banks[i].num_bytes;
				first = &mem_map[prev_end >> PAGE_SHIFT];
				last = &mem_map[last_valid_pfn];
				free_mem_map_range(first, last);
			}
		}
	}
#ifdef DEBUG_BOOTMEM
	prom_printf("\n");
#endif
}

void map_high_region(unsigned long start_pfn, unsigned long end_pfn)
{
	unsigned long tmp;

#ifdef DEBUG_HIGHMEM
	printk("mapping high region %08lx - %08lx\n", start_pfn, end_pfn);
#endif

	for (tmp = start_pfn; tmp < end_pfn; tmp++) {
		struct page *page = mem_map + tmp;

		ClearPageReserved(page);
		set_bit(PG_highmem, &page->flags);
		atomic_set(&page->count, 1);
		__free_page(page);
		totalhigh_pages++;
	}
}

void __init mem_init(void)
{
	int codepages = 0;
	int datapages = 0;
	int initpages = 0; 
	int i;
#ifdef CONFIG_BLK_DEV_INITRD
	unsigned long addr, last;
#endif

	highmem_start_page = mem_map + highstart_pfn;

	/* Saves us work later. */
	memset((void *)&empty_zero_page, 0, PAGE_SIZE);

	i = last_valid_pfn >> (8 + 5);
	i += 1;

	sparc_valid_addr_bitmap = (unsigned long *)
		__alloc_bootmem(i << 2, SMP_CACHE_BYTES, 0UL);

	if (sparc_valid_addr_bitmap == NULL) {
		prom_printf("mem_init: Cannot alloc valid_addr_bitmap.\n");
		prom_halt();
	}
	memset(sparc_valid_addr_bitmap, 0, i << 2);

	taint_real_pages();

	max_mapnr = last_valid_pfn;
	high_memory = __va(max_low_pfn << PAGE_SHIFT);

#ifdef DEBUG_BOOTMEM
	prom_printf("mem_init: Calling free_all_bootmem().\n");
#endif
	num_physpages = totalram_pages = free_all_bootmem();

#if 0
	free_unused_mem_map();
#endif

	for (i = 0; sp_banks[i].num_bytes != 0; i++) {
		unsigned long start_pfn = sp_banks[i].base_addr >> PAGE_SHIFT;
		unsigned long end_pfn = (sp_banks[i].base_addr + sp_banks[i].num_bytes) >> PAGE_SHIFT;

		if (end_pfn <= highstart_pfn)
			continue;

		if (start_pfn < highstart_pfn)
			start_pfn = highstart_pfn;

		map_high_region(start_pfn, end_pfn);
	}
	
	totalram_pages += totalhigh_pages;

	codepages = (((unsigned long) &etext) - ((unsigned long)&_start));
	codepages = PAGE_ALIGN(codepages) >> PAGE_SHIFT;
	datapages = (((unsigned long) &edata) - ((unsigned long)&etext));
	datapages = PAGE_ALIGN(datapages) >> PAGE_SHIFT;
	initpages = (((unsigned long) &__init_end) - ((unsigned long) &__init_begin));
	initpages = PAGE_ALIGN(initpages) >> PAGE_SHIFT;

	printk("Memory: %dk available (%dk kernel code, %dk data, %dk init, %ldk highmem) [%08lx,%08lx]\n",
	       nr_free_pages() << (PAGE_SHIFT-10),
	       codepages << (PAGE_SHIFT-10),
	       datapages << (PAGE_SHIFT-10), 
	       initpages << (PAGE_SHIFT-10),
	       totalhigh_pages << (PAGE_SHIFT-10),
	       (unsigned long)PAGE_OFFSET, (last_valid_pfn << PAGE_SHIFT));

	/* NOTE NOTE NOTE NOTE
	 * Please keep track of things and make sure this
	 * always matches the code in mm/page_alloc.c -DaveM
	 */
	i = nr_free_pages() >> 7;
	if (i < 48)
		i = 48;
	if (i > 256)
		i = 256;
	freepages.min = i;
	freepages.low = i << 1;
	freepages.high = freepages.low + i;
}

void free_initmem (void)
{
	unsigned long addr;

	addr = (unsigned long)(&__init_begin);
	for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
		unsigned long page;
		struct page *p;

		page = addr + phys_base;
		p = virt_to_page(page);

		ClearPageReserved(p);
		set_page_count(p, 1);
		__free_page(p);
		totalram_pages++;
		num_physpages++;
	}
	printk ("Freeing unused kernel memory: %dk freed\n", (&__init_end - &__init_begin) >> 10);
}

#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
	if (start < end)
		printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
	for (; start < end; start += PAGE_SIZE) {
		struct page *p = virt_to_page(start);

		ClearPageReserved(p);
		set_page_count(p, 1);
		__free_page(p);
		num_physpages++;
	}
}
#endif

void si_meminfo(struct sysinfo *val)
{
	val->totalram = totalram_pages;
	val->sharedram = 0;
	val->freeram = nr_free_pages();
	val->bufferram = atomic_read(&buffermem_pages);
	val->totalhigh = totalhigh_pages;
	val->freehigh = nr_free_highpages();

	val->mem_unit = PAGE_SIZE;
}

void flush_page_to_ram(struct page *page)
{
	unsigned long vaddr = (unsigned long)page_address(page);

	if (vaddr)
		__flush_page_to_ram(vaddr);
}