paging/pae/X86PagingMethodPAE.cpp

65 		// page hole set up in the boot loader
69 		// calculate where the page dir would be
76 		TRACE("page hole: %p\n", fPageHole);
77 		TRACE("page dir:  %p (physical: %#" B_PRIxPHYSADDR ")\n",
87 		// count the page tables we have to translate
96 		TRACE("page tables to translate: %" B_PRIu32 "\n", pageTableCount);
99 		// + 1 page dir pointer table
100 		// + 4 page dirs
101 		// + 2 * page tables (each has 512 instead of 1024 entries)
102 		// + 1 page for the free virtual slot (no physical page needed)
105 		// We need additional PAE page tables for the new pages we're going to
108 		// page tables, but we don't need additional virtual space for them,
109 		// since we can access then via the page hole.
117 		// prepare the page directory pointer table
132 		// and setting the cr4 PAE bit -- we copy the kernel page dir entries to
133 		// the PDPT page, so after setting cr3, we continue to have working
135 		// page dir entries don't interect, obviously.
139 		// translate the page tables
143 				// two PAE page tables per 32 bit page table
147 				// copy the page directory entry to the PDPT page
191 		// allocate a PAE page table
196 		// enter it into the page dir
240 		// allocate pages for the 32 bit page tables and prepare the tables
243 			// allocate a page
246 			// put the page into the page dir
258 		// We don't need a physical page for the free virtual slot.
263 			// allocate a page
266 			// put the page into the page table
272 			// Write the page's physical address into the page itself, so we
290 			panic("Failed to allocate page for the switch to PAE!");
298 			panic("Failed to allocate 32 bit addressable page for the switch "
313 		void* page = fAllocatedPages + (fUsedPagesCount++) * B_PAGE_SIZE;
314 		_physicalAddress = *((phys_addr_t*)page);
317 			memset(page, 0, B_PAGE_SIZE);
319 		return page;
403 			"physical page pool space in virtual address space!");
407 	// allocate memory for the page table and data
414 			"to allocate memory for page table!");
418 	// clear the page table and put it in the page dir
444 	area_id area = create_area("physical page pool", &temp,
449 			"create area for physical page pool.");
457 		"physical page pool space", &temp, B_EXACT_ADDRESS,
461 			"create area for physical page pool space.");
518 	// create an area that can contain the page table and the slot
526 	area_id dataArea = create_area_etc(B_SYSTEM_TEAM, "physical page pool",
536 		VMAddressSpace::KernelID(), "physical page pool space",
544 	// prepare the page table
547 	// get the page table's physical address
556 	// put the page table into the page directory
601 	// create the initial pools for the physical page mapper
610 				"for physical page mapper!");
615 	// create physical page mapper
634 	// let the initial page pools create areas for its structures
643 	// The early physical page mapping mechanism is no longer needed. Unmap the
678 	// check to see if a page table exists for this range
683 		// we need to allocate a page table
686 		TRACE("X86PagingMethodPAE::MapEarly(): asked for free page for "
687 			"page table: %#" B_PRIxPHYSADDR "\n", physicalPageTable);
689 		// put it in the page dir
721 	// we can't check much without the physical page mapper
725 	// We only trust the kernel team's page directories. So switch to the
749 	// map the page dir and get the entry
763 	// map the page table and get the entry
778 	// switch back to the original page directory
799 		// TODO: We ignore the attributes of the page table -- for compatibility
814 	pae_page_table_entry page = (physicalAddress & X86_PAE_PTE_ADDRESS_MASK)
818 	// if the page is user accessible, it's automatically
822 		page |= X86_PAE_PTE_USER;
824 			page |= X86_PAE_PTE_WRITABLE;
827 			page |= X86_PAE_PTE_NOT_EXECUTABLE;
830 		page |= X86_PAE_PTE_WRITABLE;
832 	// put it in the page table
833 	SetTableEntry(entry, page);
841 	// get a free page
843 	vm_page* page;
845 		page = fFreePages;
846 		fFreePages = page->cache_next;
855 		page = vm_page_allocate_page_run(PAGE_STATE_UNUSED, 1, &restrictions,
857 		if (page == NULL)
860 		DEBUG_PAGE_ACCESS_END(page);
863 	// map the page
865 		= (phys_addr_t)page->physical_page_number * B_PAGE_SIZE;
869 		// mapping failed -- free page
871 		page->cache_next = fFreePages;
872 		fFreePages = page;
886 	// unmap the page
890 	vm_page* page = vm_lookup_page(physicalAddress / B_PAGE_SIZE);
894 		page->cache_next = fFreePages;
895 		fFreePages = page;
900 		DEBUG_PAGE_ACCESS_START(page);
901 		vm_page_free(NULL, page);
931 		// page mapping not valid