init.c

linux-2.6.15.6

	 */
	start = 0;
	size = 0;
	for (i = 0; i < phys_avail.n_regions; ++i) {
		unsigned long a = phys_avail.regions[i].address;
		unsigned long s = phys_avail.regions[i].size;
		if (s <= size)
			continue;
		start = a;
		size = s;
		if (s >= 33 * PAGE_SIZE)
			break;
	}
	start = PAGE_ALIGN(start);

	min_low_pfn = start >> PAGE_SHIFT;
	max_low_pfn = (PPC_MEMSTART + total_lowmem) >> PAGE_SHIFT;
	max_pfn = (PPC_MEMSTART + total_memory) >> PAGE_SHIFT;
	boot_mapsize = init_bootmem_node(&contig_page_data, min_low_pfn,
					 PPC_MEMSTART >> PAGE_SHIFT,
					 max_low_pfn);

	/* remove the bootmem bitmap from the available memory */
	mem_pieces_remove(&phys_avail, start, boot_mapsize, 1);

	/* add everything in phys_avail into the bootmem map */
	for (i = 0; i < phys_avail.n_regions; ++i)
		free_bootmem(phys_avail.regions[i].address,
			     phys_avail.regions[i].size);

	init_bootmem_done = 1;
}

/*
 * 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;

#ifdef CONFIG_HIGHMEM
	map_page(PKMAP_BASE, 0, 0);	/* XXX gross */
	pkmap_page_table = pte_offset_kernel(pmd_offset(pgd_offset_k
			(PKMAP_BASE), PKMAP_BASE), PKMAP_BASE);
	map_page(KMAP_FIX_BEGIN, 0, 0);	/* XXX gross */
	kmap_pte = pte_offset_kernel(pmd_offset(pgd_offset_k
			(KMAP_FIX_BEGIN), KMAP_FIX_BEGIN), KMAP_FIX_BEGIN);
	kmap_prot = PAGE_KERNEL;
#endif /* CONFIG_HIGHMEM */

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

#ifdef CONFIG_HIGHMEM
	zones_size[ZONE_HIGHMEM] = (total_memory - total_lowmem) >> PAGE_SHIFT;
#endif /* CONFIG_HIGHMEM */

	free_area_init(zones_size);
}

void __init mem_init(void)
{
	unsigned long addr;
	int codepages = 0;
	int datapages = 0;
	int initpages = 0;
#ifdef CONFIG_HIGHMEM
	unsigned long highmem_mapnr;

	highmem_mapnr = total_lowmem >> PAGE_SHIFT;
#endif /* CONFIG_HIGHMEM */
	max_mapnr = total_memory >> PAGE_SHIFT;

	high_memory = (void *) __va(PPC_MEMSTART + total_lowmem);
	num_physpages = max_mapnr;	/* RAM is assumed contiguous */

	totalram_pages += free_all_bootmem();

#ifdef CONFIG_BLK_DEV_INITRD
	/* if we are booted from BootX with an initial ramdisk,
	   make sure the ramdisk pages aren't reserved. */
	if (initrd_start) {
		for (addr = initrd_start; addr < initrd_end; addr += PAGE_SIZE)
			ClearPageReserved(virt_to_page(addr));
	}
#endif /* CONFIG_BLK_DEV_INITRD */

#ifdef CONFIG_PPC_OF
	/* mark the RTAS pages as reserved */
	if ( rtas_data )
		for (addr = (ulong)__va(rtas_data);
		     addr < PAGE_ALIGN((ulong)__va(rtas_data)+rtas_size) ;
		     addr += PAGE_SIZE)
			SetPageReserved(virt_to_page(addr));
#endif
#ifdef CONFIG_PPC_PMAC
	if (agp_special_page)
		SetPageReserved(virt_to_page(agp_special_page));
#endif
	for (addr = PAGE_OFFSET; addr < (unsigned long)high_memory;
	     addr += PAGE_SIZE) {
		if (!PageReserved(virt_to_page(addr)))
			continue;
		if (addr < (ulong) etext)
			codepages++;
		else if (addr >= (unsigned long)&__init_begin
			 && addr < (unsigned long)&__init_end)
			initpages++;
		else if (addr < (ulong) klimit)
			datapages++;
	}

#ifdef CONFIG_HIGHMEM
	{
		unsigned long pfn;

		for (pfn = highmem_mapnr; pfn < max_mapnr; ++pfn) {
			struct page *page = mem_map + pfn;

			ClearPageReserved(page);
			set_page_count(page, 1);
			__free_page(page);
			totalhigh_pages++;
		}
		totalram_pages += totalhigh_pages;
	}
#endif /* CONFIG_HIGHMEM */

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

#ifdef CONFIG_PPC_PMAC
	if (agp_special_page)
		printk(KERN_INFO "AGP special page: 0x%08lx\n", agp_special_page);
#endif

	mem_init_done = 1;
}

/*
 * Set phys_avail to the amount of physical memory,
 * less the kernel text/data/bss.
 */
void __init
set_phys_avail(unsigned long total_memory)
{
	unsigned long kstart, ksize;

	/*
	 * Initially, available physical memory is equivalent to all
	 * physical memory.
	 */

	phys_avail.regions[0].address = PPC_MEMSTART;
	phys_avail.regions[0].size = total_memory;
	phys_avail.n_regions = 1;

	/*
	 * Map out the kernel text/data/bss from the available physical
	 * memory.
	 */

	kstart = __pa(_stext);	/* should be 0 */
	ksize = PAGE_ALIGN(klimit - _stext);

	mem_pieces_remove(&phys_avail, kstart, ksize, 0);
	mem_pieces_remove(&phys_avail, 0, 0x4000, 0);

#if defined(CONFIG_BLK_DEV_INITRD)
	/* Remove the init RAM disk from the available memory. */
	if (initrd_start) {
		mem_pieces_remove(&phys_avail, __pa(initrd_start),
				  initrd_end - initrd_start, 1);
	}
#endif /* CONFIG_BLK_DEV_INITRD */
#ifdef CONFIG_PPC_OF
	/* remove the RTAS pages from the available memory */
	if (rtas_data)
		mem_pieces_remove(&phys_avail, rtas_data, rtas_size, 1);
#endif
#ifdef CONFIG_PPC_PMAC
	/* Because of some uninorth weirdness, we need a page of
	 * memory as high as possible (it must be outside of the
	 * bus address seen as the AGP aperture). It will be used
	 * by the r128 DRM driver
	 *
	 * FIXME: We need to make sure that page doesn't overlap any of the\
	 * above. This could be done by improving mem_pieces_find to be able
	 * to do a backward search from the end of the list.
	 */
	if (_machine == _MACH_Pmac && find_devices("uni-north-agp")) {
		agp_special_page = (total_memory - PAGE_SIZE);
		mem_pieces_remove(&phys_avail, agp_special_page, PAGE_SIZE, 0);
		agp_special_page = (unsigned long)__va(agp_special_page);
	}
#endif /* CONFIG_PPC_PMAC */
}

/* Mark some memory as reserved by removing it from phys_avail. */
void __init reserve_phys_mem(unsigned long start, unsigned long size)
{
	mem_pieces_remove(&phys_avail, start, size, 1);
}

/*
 * 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_dcache_icache_page(struct page *page)
{
#ifdef CONFIG_BOOKE
	void *start = kmap_atomic(page, KM_PPC_SYNC_ICACHE);
	__flush_dcache_icache(start);
	kunmap_atomic(start, KM_PPC_SYNC_ICACHE);
#elif defined(CONFIG_8xx)
	/* On 8xx there is no need to kmap since highmem is not supported */
	__flush_dcache_icache(page_address(page)); 
#else
	__flush_dcache_icache_phys(page_to_pfn(page) << PAGE_SHIFT);
#endif

}
void clear_user_page(void *page, unsigned long vaddr, struct page *pg)
{
	clear_page(page);
	clear_bit(PG_arch_1, &pg->flags);
}

void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
		    struct page *pg)
{
	copy_page(vto, vfrom);
	clear_bit(PG_arch_1, &pg->flags);
}

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

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

/*
 * This is called at the end of handling a user page fault, when the
 * fault has been handled by updating a PTE in the linux page tables.
 * We use it to preload an HPTE into the hash table corresponding to
 * the updated linux PTE.
 */
void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
		      pte_t pte)
{
	/* handle i-cache coherency */
	unsigned long pfn = pte_pfn(pte);

	if (pfn_valid(pfn)) {
		struct page *page = pfn_to_page(pfn);
#ifdef CONFIG_8xx
		/* On 8xx, the TLB handlers work in 2 stages:
	 	 * First, a zeroed entry is loaded by TLBMiss handler,
		 * which causes the TLBError handler to be triggered.
		 * That means the zeroed TLB has to be invalidated
		 * whenever a page miss occurs.
		 */
		_tlbie(address);
#endif
		if (!PageReserved(page)
		    && !test_bit(PG_arch_1, &page->flags)) {
			if (vma->vm_mm == current->active_mm)
				__flush_dcache_icache((void *) address);
			else
				flush_dcache_icache_page(page);
			set_bit(PG_arch_1, &page->flags);
		}
	}

#ifdef CONFIG_PPC_STD_MMU
	/* We only want HPTEs for linux PTEs that have _PAGE_ACCESSED set */
	if (Hash != 0 && pte_young(pte)) {
		struct mm_struct *mm;
		pmd_t *pmd;

		mm = (address < TASK_SIZE)? vma->vm_mm: &init_mm;
		pmd = pmd_offset(pgd_offset(mm, address), address);
		if (!pmd_none(*pmd))
			add_hash_page(mm->context, address, pmd_val(*pmd));
	}
#endif
}

/*
 * This is called by /dev/mem to know if a given address has to
 * be mapped non-cacheable or not
 */
int page_is_ram(unsigned long pfn)
{
	return pfn < max_pfn;
}

pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
			      unsigned long size, pgprot_t vma_prot)
{
	if (ppc_md.phys_mem_access_prot)
		return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);

	if (!page_is_ram(pfn))
		vma_prot = __pgprot(pgprot_val(vma_prot)
				    | _PAGE_GUARDED | _PAGE_NO_CACHE);
	return vma_prot;
}
EXPORT_SYMBOL(phys_mem_access_prot);