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extern pud_t level3_kernel_pgt[512];extern pud_t level3_ident_pgt[512];extern pmd_t level2_kernel_pgt[512];extern pmd_t level2_fixmap_pgt[512];extern pmd_t level2_ident_pgt[512];extern pte_t level1_fixmap_pgt[512];extern pgd_t init_top_pgt[];

#define swapper_pg_dir init_top_pgt

__INITDATA
NEXT_PAGE(init_top_pgt) .quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE .org init_top_pgt + PGD_PAGE_OFFSET*8, 0 .quad level3_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE .org init_top_pgt + PGD_START_KERNEL*8, 0 /* (2^48-(2*1024*1024*1024))/(2^39) = 511 */ .quad level3_kernel_pgt - __START_KERNEL_map + _PAGE_TABLE

NEXT_PAGE(level3_ident_pgt) .quad level2_ident_pgt - __START_KERNEL_map + _KERNPG_TABLE .fill 511, 8, 0NEXT_PAGE(level2_ident_pgt) /* Since I easily can, map the first 1G. * Don't set NX because code runs from these pages. */ PMDS(0, __PAGE_KERNEL_IDENT_LARGE_EXEC, PTRS_PER_PMD)

NEXT_PAGE(level3_kernel_pgt) .fill L3_START_KERNEL,8,0 /* (2^48-(2*1024*1024*1024)-((2^39)*511))/(2^30) = 510 */ .quad level2_kernel_pgt - __START_KERNEL_map + _KERNPG_TABLE .quad level2_fixmap_pgt - __START_KERNEL_map + _PAGE_TABLE

NEXT_PAGE(level2_kernel_pgt) /* * 512 MB kernel mapping. We spend a full page on this pagetable * anyway. * * The kernel code+data+bss must not be bigger than that. * * (NOTE: at +512MB starts the module area, see MODULES_VADDR. * If you want to increase this then increase MODULES_VADDR * too.) */ PMDS(0, __PAGE_KERNEL_LARGE_EXEC, KERNEL_IMAGE_SIZE/PMD_SIZE)

NEXT_PAGE(level2_fixmap_pgt) .fill 506,8,0 .quad level1_fixmap_pgt - __START_KERNEL_map + _PAGE_TABLE /* 8MB reserved for vsyscalls + a 2MB hole = 4 + 1 entries */ .fill 5,8,0

NEXT_PAGE(level1_fixmap_pgt) .fill 51

PGD_PAGE_OFFSET = pgd_index(__PAGE_OFFSET_BASE)PGD_START_KERNEL = pgd_index(__START_KERNEL_map)L3_START_KERNEL = pud_index(__START_KERNEL_map)

struct mm_struct init_mm = { .mm_rb = RB_ROOT, .pgd = swapper_pg_dir, .mm_users = ATOMIC_INIT(2), .mm_count = ATOMIC_INIT(1), .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem), .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), .mmlist = LIST_HEAD_INIT(init_mm.mmlist), .user_ns = &init_user_ns, INIT_MM_CONTEXT(init_mm)};

void __init setup_arch(char **cmdline_p){ /* * copy kernel address range established so far and switch * to the proper swapper page table */ clone_pgd_range(swapper_pg_dir + KERNEL_PGD_BOUNDARY, initial_page_table + KERNEL_PGD_BOUNDARY, KERNEL_PGD_PTRS);

 load_cr3(swapper_pg_dir); __flush_tlb_all();...... init_mm.start_code = (unsigned long) _text; init_mm.end_code = (unsigned long) _etext; init_mm.end_data = (unsigned long) _edata; init_mm.brk = _brk_end;...... init_mem_mapping();......}

/* * Create page table mapping for the physical memory for specific physical * addresses. The virtual and physical addresses have to be aligned on PMD level * down. It returns the last physical address mapped. */unsigned long __meminitkernel_physical_mapping_init(unsigned long paddr_start, unsigned long paddr_end, unsigned long page_size_mask){ unsigned long vaddr, vaddr_start, vaddr_end, vaddr_next, paddr_last;

 paddr_last = paddr_end; vaddr = (unsigned long)__va(paddr_start); vaddr_end = (unsigned long)__va(paddr_end); vaddr_start = vaddr;

 for (; vaddr < vaddr_end; vaddr = vaddr_next) { pgd_t *pgd = pgd_offset_k(vaddr); p4d_t *p4d;

 vaddr_next = (vaddr & PGDIR_MASK) + PGDIR_SIZE;

 if (pgd_val(*pgd)) { p4d = (p4d_t *)pgd_page_vaddr(*pgd); paddr_last = phys_p4d_init(p4d, __pa(vaddr), __pa(vaddr_end), page_size_mask); continue; }

 p4d = alloc_low_page(); paddr_last = phys_p4d_init(p4d, __pa(vaddr), __pa(vaddr_end), page_size_mask);

 p4d_populate(&init_mm, p4d_offset(pgd, vaddr), (pud_t *) p4d); } __flush_tlb_all();

 return paddr_l

/** * vmalloc - allocate virtually contiguous memory * @size: allocation size * Allocate enough pages to cover @size from the page level * allocator and map them into contiguous kernel virtual space. * * For tight control over page level allocator and protection flags * use __vmalloc() instead. */void *vmalloc(unsigned long size){ return __vmalloc_node_flags(size, NUMA_NO_NODE, GFP_KERNEL);}

static void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask, pgprot_t prot, int node, const void *caller){ return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END, gfp_mask, prot, 0, node, caller);}

void *kmap_atomic_prot(struct page *page, pgprot_t prot){...... if (!PageHighMem(page)) return page_address(page);...... vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); set_pte(kmap_pte-idx, mk_pte(page, prot));...... return (void *)vaddr;}

void *kmap_atomic(struct page *page){ return kmap_atomic_prot(page, kmap_prot);}

static __always_inline void *lowmem_page_address(const struct page *page){ return page_to_virt(page);}

#define page_to_virt(x) __va(PFN_PHYS(page_to_pfn(x)

/* * 32-bit: * * Handle a fault on the vmalloc or module mapping area */static noinline int vmalloc_fault(unsigned long address){ unsigned long pgd_paddr; pmd_t *pmd_k; pte_t *pte_k;

 /* Make sure we are in vmalloc area: */ if (!(address >= VMALLOC_START && address < VMALLOC_END)) return -1;

 /* * Synchronize this task's top level page-table * with the 'reference' page table. * * Do _not_ use "current" here. We might be inside * an interrupt in the middle of a task switch.. */ pgd_paddr = read_cr3_pa(); pmd_k = vmalloc_sync_one(__va(pgd_paddr), address); if (!pmd_k) return -1;

 pte_k = pte_offset_kernel(pmd_k, address); if (!pte_present(*pte_k)) return -1;

 return 0