/*
 * Copyright (c) 1996, 1998, 1999 University of Utah and the Flux Group.
 * All rights reserved.
 * 
 * This file is part of the Flux OSKit.  The OSKit is free software, also known
 * as "open source;" you can redistribute it and/or modify it under the terms
 * of the GNU General Public License (GPL), version 2, as published by the Free
 * Software Foundation (FSF).  To explore alternate licensing terms, contact
 * the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
 * 
 * The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GPL for more details.  You should have
 * received a copy of the GPL along with the OSKit; see the file COPYING.  If
 * not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
 */

#include <oskit/debug.h>
#include <oskit/page.h>
#include <oskit/arm32/base_paging.h>

void pdir_prot_range(oskit_addr_t pdir_pa, oskit_addr_t va, oskit_size_t size,
		     pt_entry_t new_mapping_bits)
{
	assert(new_mapping_bits & ARM32_PTE_TYPE_MASK);
	assert(!(new_mapping_bits & ARM32_PTE_PFN_SPAGE));

	while (size > 0)
	{
		pd_entry_t *pde = pdir_find_pde(pdir_pa, va);

		assert(*pde & ARM32_PDE_TYPE_MASK);

		if (*pde & ARM32_PDE_TYPE_SECTION)
		{
			/*
			 * A superpage was used to map an entire 1MB region.
			 * Just change the mapping bits in the superpage entry.
			 */
			assert(superpage_aligned(va));
			assert(size >= SUPERPAGE_SIZE);
			*pde = (*pde & ARM32_PDE_PFN_SECTION)|new_mapping_bits;
			va += SUPERPAGE_SIZE;
			size -= SUPERPAGE_SIZE;
		}
		else
		{
			pt_entry_t *pte;

			/* Find the page table for this 4KB region.  */
			pte = ptab_find_pte(pde_to_pa(*pde), va);

			/* Change the affected 4KB page mappings.  */
			do
			{
				/* Change the bits in the page mapping.  */
				assert(*pte & ARM32_PTE_TYPE_MASK);
				*pte = (*pte & ARM32_PTE_PFN_SPAGE)
					| new_mapping_bits;

				/* Advance to the next page.  */
				pte++;
				va += PAGE_SIZE;
				size -= PAGE_SIZE;
			}
			while ((size > 0) && !superpage_aligned(va));
		}
	}
}