init.c

linux-2.4.29操作系统的源码

						++ptep;
					} while ( start < pmd_end );
				}
				else
					start = pmd_end;
				++pmd;
			} while ( start < pgd_end );
		}
		else
			start = pgd_end;
		++pgd;
	} while ( start < end );
}


void __init free_initmem(void)
{
	unsigned long a;
	unsigned long num_freed_pages = 0;
#define FREESEC(START,END,CNT) do { \
	a = (unsigned long)(&START); \
	for (; a < (unsigned long)(&END); a += PAGE_SIZE) { \
	  	clear_bit(PG_reserved, &mem_map[MAP_NR(a)].flags); \
		set_page_count(mem_map+MAP_NR(a), 1); \
		free_page(a); \
		CNT++; \
	} \
} while (0)

	FREESEC(__init_begin,__init_end,num_freed_pages);

	printk ("Freeing unused kernel memory: %ldk init\n",
		PGTOKB(num_freed_pages));
}

#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
	unsigned long xstart = start;
	for (; start < end; start += PAGE_SIZE) {
		ClearPageReserved(mem_map + MAP_NR(start));
		set_page_count(mem_map+MAP_NR(start), 1);
		free_page(start);
		totalram_pages++;
	}
	printk ("Freeing initrd memory: %ldk freed\n", (end - xstart) >> 10);
}
#endif

/*
 * Do very early mm setup.
 */
void __init mm_init_ppc64(void)
{
	struct paca_struct *lpaca;
	unsigned long guard_page, index;

	ppc_md.progress("MM:init", 0);

	/* Reserve all contexts < FIRST_USER_CONTEXT for kernel use.
	 * The range of contexts [FIRST_USER_CONTEXT, NUM_USER_CONTEXT)
	 * are stored on a stack/queue for easy allocation and deallocation.
	 */
	mmu_context_queue.lock = SPIN_LOCK_UNLOCKED;
	mmu_context_queue.head = 0;
	mmu_context_queue.tail = NUM_USER_CONTEXT-1;
	mmu_context_queue.size = NUM_USER_CONTEXT;
	for(index=0; index < NUM_USER_CONTEXT ;index++) {
		mmu_context_queue.elements[index] = index+FIRST_USER_CONTEXT;
	}

	/* Setup guard pages for the Paca's */
	for (index = 0; index < NR_CPUS; index++) {
		lpaca = &paca[index];
		guard_page = ((unsigned long)lpaca) + 0x1000;
		ppc_md.hpte_updateboltedpp(PP_RXRX, guard_page);
	}

	ppc_md.progress("MM:exit", 0x211);
}

/*
 * Initialize the bootmem system and give it all the memory we
 * have available.
 */
void __init do_init_bootmem(void)
{
	unsigned long i;
	unsigned long start, bootmap_pages;
	unsigned long total_pages = lmb_end_of_DRAM() >> PAGE_SHIFT;

	PPCDBG(PPCDBG_MMINIT, "do_init_bootmem: start\n");
	/*
	 * Find an area to use for the bootmem bitmap.  Calculate the size of
	 * bitmap required as (Total Memory) / PAGE_SIZE / BITS_PER_BYTE.
	 * Add 1 additional page in case the address isn't page-aligned.
	 */
	bootmap_pages = bootmem_bootmap_pages(total_pages);

	start = (unsigned long)__a2p(lmb_alloc(bootmap_pages<<PAGE_SHIFT, PAGE_SIZE));
	if (start == 0) {
		udbg_printf("do_init_bootmem: failed to allocate a bitmap.\n");
		udbg_printf("\tbootmap_pages = 0x%lx.\n", bootmap_pages);
		PPCDBG_ENTER_DEBUGGER(); 
	}

	PPCDBG(PPCDBG_MMINIT, "\tstart               = 0x%lx\n", start);
	PPCDBG(PPCDBG_MMINIT, "\tbootmap_pages       = 0x%lx\n", bootmap_pages);
	PPCDBG(PPCDBG_MMINIT, "\tphysicalMemorySize  = 0x%lx\n", systemcfg->physicalMemorySize);

	boot_mapsize = init_bootmem(start >> PAGE_SHIFT, total_pages);
	PPCDBG(PPCDBG_MMINIT, "\tboot_mapsize        = 0x%lx\n", boot_mapsize);

	/* add all physical memory to the bootmem map */
	for (i=0; i < lmb.memory.cnt; i++) {
		unsigned long physbase, size;
		unsigned long type = lmb.memory.region[i].type;

		if ( type != LMB_MEMORY_AREA )
			continue;

		physbase = lmb.memory.region[i].physbase;
		size = lmb.memory.region[i].size;
		free_bootmem(physbase, size);
	}
	/* reserve the sections we're already using */
	for (i=0; i < lmb.reserved.cnt; i++) {
		unsigned long physbase = lmb.reserved.region[i].physbase;
		unsigned long size = lmb.reserved.region[i].size;
#if 0 /* PPPBBB */
		if ( (physbase == 0) && (size < (16<<20)) ) {
			size = 16 << 20;
		}
#endif
		reserve_bootmem(physbase, size);
	}

	PPCDBG(PPCDBG_MMINIT, "do_init_bootmem: end\n");
}

/*
 * paging_init() sets up the page tables - in fact we've already done this.
 */
void __init paging_init(void)
{
	unsigned long zones_size[MAX_NR_ZONES], i;

	/*
	 * All pages are DMA-able so we put them all in the DMA zone.
	 */
	zones_size[ZONE_DMA] = lmb_end_of_DRAM() >> PAGE_SHIFT;
	for (i = 1; i < MAX_NR_ZONES; i++)
		zones_size[i] = 0;
	free_area_init(zones_size);
}

void initialize_paca_hardware_interrupt_stack(void);

void __init mem_init(void)
{
	extern char *sysmap; 
	extern unsigned long sysmap_size;
	unsigned long addr;
	int codepages = 0;
	int datapages = 0;
	int initpages = 0;
	unsigned long va_rtas_base = (unsigned long)__va(rtas.base);

	max_mapnr = max_low_pfn;
	high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
	num_physpages = max_mapnr;	/* RAM is assumed contiguous */

	totalram_pages += free_all_bootmem();

	ifppcdebug(PPCDBG_MMINIT) {
		udbg_printf("mem_init: totalram_pages = 0x%lx\n", totalram_pages);
		udbg_printf("mem_init: va_rtas_base   = 0x%lx\n", va_rtas_base); 
		udbg_printf("mem_init: va_rtas_end    = 0x%lx\n", PAGE_ALIGN(va_rtas_base+rtas.size)); 
		udbg_printf("mem_init: pinned start   = 0x%lx\n", __va(0)); 
		udbg_printf("mem_init: pinned end     = 0x%lx\n", PAGE_ALIGN(klimit)); 
	}

	if ( sysmap_size )
		for (addr = (unsigned long)sysmap;
		     addr < PAGE_ALIGN((unsigned long)sysmap+sysmap_size) ;
		     addr += PAGE_SIZE)
			SetPageReserved(mem_map + MAP_NR(addr));
	
	for (addr = KERNELBASE; addr <= (unsigned long)__va(lmb_end_of_DRAM());
	     addr += PAGE_SIZE) {
		if (!PageReserved(mem_map + MAP_NR(addr)))
			continue;
		if (addr < (ulong) etext)
			codepages++;

		else if (addr >= (unsigned long)&__init_begin
			 && addr < (unsigned long)&__init_end)
			initpages++;
		else if (addr < klimit)
			datapages++;
	}

	printk("Memory: %luk available (%dk kernel code, %dk data, %dk init) [%08lx,%08lx]\n",
	       (unsigned long)nr_free_pages()<< (PAGE_SHIFT-10),
	       codepages<< (PAGE_SHIFT-10), datapages<< (PAGE_SHIFT-10),
	       initpages<< (PAGE_SHIFT-10),
	       PAGE_OFFSET, (unsigned long)__va(lmb_end_of_DRAM()));
	mem_init_done = 1;

	/* set the last page of each hardware interrupt stack to be protected */
	initialize_paca_hardware_interrupt_stack();

#ifdef CONFIG_PPC_ISERIES
	create_virtual_bus_tce_table();
#endif
}

/*
 * This is called when a page has been modified by the kernel.
 * It just marks the page as not i-cache clean.  We do the i-cache
 * flush later when the page is given to a user process, if necessary.
 */
void flush_dcache_page(struct page *page)
{
	clear_bit(PG_arch_1, &page->flags);
}

void flush_icache_page(struct vm_area_struct *vma, struct page *page)
{
	if (page->mapping && !PageReserved(page)
	    && !test_bit(PG_arch_1, &page->flags)) {
		__flush_dcache_icache(page_address(page));
		set_bit(PG_arch_1, &page->flags);
	}
}

void clear_user_page(void *page, unsigned long vaddr)
{
	clear_page(page);
	__flush_dcache_icache(page);
}

void copy_user_page(void *vto, void *vfrom, unsigned long vaddr)
{
	copy_page(vto, vfrom);
	__flush_dcache_icache(vto);
}

void flush_icache_user_range(struct vm_area_struct *vma, struct page *page,
			     unsigned long addr, int len)
{
	unsigned long maddr;

	maddr = (unsigned long)page_address(page) + (addr & ~PAGE_MASK);
	flush_icache_range(maddr, maddr + len);
}

#ifdef CONFIG_SHARED_MEMORY_ADDRESSING
static spinlock_t shared_malloc_lock = SPIN_LOCK_UNLOCKED;
struct vm_struct *shared_list = NULL;
static struct vm_struct *get_shared_area(unsigned long size, 
					 unsigned long flags);

void *shared_malloc(unsigned long size)
{
	pgprot_t prot;
	struct vm_struct *area;
	unsigned long ea;

	spin_lock(&shared_malloc_lock);

	printk("shared_malloc1 (no _PAGE_USER): addr = 0x%lx, size = 0x%lx\n", 
	       SMALLOC_START, size); 

	area = get_shared_area(size, 0);
	if (!area) {
	spin_unlock(&shared_malloc_lock);
		return NULL;
	}

	ea = (unsigned long) area->addr;

	prot = __pgprot(pgprot_val(PAGE_KERNEL));
	if (vmalloc_area_pages(VMALLOC_VMADDR(ea), size, GFP_KERNEL, prot)) { 
	spin_unlock(&shared_malloc_lock);
		return NULL;
	} 

	printk("shared_malloc: addr = 0x%lx, size = 0x%lx\n", ea, size); 

	spin_unlock(&shared_malloc_lock);
	return(ea); 
}

void shared_free(void *addr)
{
	struct vm_struct **p, *tmp;

	if (!addr)
		return;
	if ((PAGE_SIZE-1) & (unsigned long) addr) {
		printk(KERN_ERR "Trying to shared_free() bad address (%p)\n", 
		       addr);
		return;
	}
	spin_lock(&shared_malloc_lock);

	printk("shared_free: addr = 0x%p\n", addr);

	/* Scan the memory list for an entry matching
	 * the address to be freed, get the size (in bytes)
	 * and free the entry.  The list lock is not dropped
	 * until the page table entries are removed.
	 */
	for(p = &shared_list; (tmp = *p); p = &tmp->next ) {
		if (tmp->addr == addr) {
			*p = tmp->next;
			vmfree_area_pages(VMALLOC_VMADDR(tmp->addr),tmp->size);
			spin_unlock(&shared_malloc_lock);
			kfree(tmp);
			return;
		}
	}

	spin_unlock(&shared_malloc_lock);
	printk("shared_free: error\n"); 
}

static struct vm_struct *get_shared_area(unsigned long size, 
					 unsigned long flags)
{
	unsigned long addr;
	struct vm_struct **p, *tmp, *area;
  
	area = (struct vm_struct *) kmalloc(sizeof(*area), GFP_KERNEL);
	if (!area) return NULL;

	size += PAGE_SIZE;
	if (!size) {
		kfree (area);
		return NULL;
	}

	addr = SMALLOC_START;
	for (p = &shared_list; (tmp = *p) ; p = &tmp->next) {
		if ((size + addr) < addr) {
			kfree(area);
			return NULL;
		}
		if (size + addr <= (unsigned long) tmp->addr)
			break;
		addr = tmp->size + (unsigned long) tmp->addr;
		if (addr > SMALLOC_END-size) {
			kfree(area);
			return NULL;
		}
	}

	if (addr + size > SMALLOC_END) {
		kfree(area);
		return NULL;
	}
	area->flags = flags;
	area->addr = (void *)addr;
	area->size = size;
	area->next = *p;
	*p = area;
	return area;
}

int shared_task_mark(void)
{
	current->thread.flags |= PPC_FLAG_SHARED;
	printk("current->thread.flags = 0x%lx\n", current->thread.flags);

	return 0;
}

int shared_task_unmark()
{
	if(current->thread.flags & PPC_FLAG_SHARED) {
		current->thread.flags &= (~PPC_FLAG_SHARED);
		return 0;
	} else {
		return -1;
	}
}
#endif