/* * Initialize MMU support. * * Copyright (C) 1998-2003 Hewlett-Packard Co * David Mosberger-Tang */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); DEFINE_PER_CPU(unsigned long *, __pgtable_quicklist); DEFINE_PER_CPU(long, __pgtable_quicklist_size); extern void ia64_tlb_init (void); unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL; #ifdef CONFIG_VIRTUAL_MEM_MAP unsigned long vmalloc_end = VMALLOC_END_INIT; EXPORT_SYMBOL(vmalloc_end); struct page *vmem_map; EXPORT_SYMBOL(vmem_map); #endif struct page *zero_page_memmap_ptr; /* map entry for zero page */ EXPORT_SYMBOL(zero_page_memmap_ptr); #define MIN_PGT_PAGES 25UL #define MAX_PGT_FREES_PER_PASS 16L #define PGT_FRACTION_OF_NODE_MEM 16 static inline long max_pgt_pages(void) { u64 node_free_pages, max_pgt_pages; #ifndef CONFIG_NUMA node_free_pages = nr_free_pages(); #else node_free_pages = nr_free_pages_pgdat(NODE_DATA(numa_node_id())); #endif max_pgt_pages = node_free_pages / PGT_FRACTION_OF_NODE_MEM; max_pgt_pages = max(max_pgt_pages, MIN_PGT_PAGES); return max_pgt_pages; } static inline long min_pages_to_free(void) { long pages_to_free; pages_to_free = pgtable_quicklist_size - max_pgt_pages(); pages_to_free = min(pages_to_free, MAX_PGT_FREES_PER_PASS); return pages_to_free; } void check_pgt_cache(void) { long pages_to_free; if (unlikely(pgtable_quicklist_size <= MIN_PGT_PAGES)) return; preempt_disable(); while (unlikely((pages_to_free = min_pages_to_free()) > 0)) { while (pages_to_free--) { free_page((unsigned long)pgtable_quicklist_alloc()); } preempt_enable(); preempt_disable(); } preempt_enable(); } void lazy_mmu_prot_update (pte_t pte) { unsigned long addr; struct page *page; if (!pte_exec(pte)) return; /* not an executable page... */ page = pte_page(pte); addr = (unsigned long) page_address(page); if (test_bit(PG_arch_1, &page->flags)) return; /* i-cache is already coherent with d-cache */ flush_icache_range(addr, addr + PAGE_SIZE); set_bit(PG_arch_1, &page->flags); /* mark page as clean */ } inline void ia64_set_rbs_bot (void) { unsigned long stack_size = current->signal->rlim[RLIMIT_STACK].rlim_max & -16; if (stack_size > MAX_USER_STACK_SIZE) stack_size = MAX_USER_STACK_SIZE; current->thread.rbs_bot = STACK_TOP - stack_size; } /* * This performs some platform-dependent address space initialization. * On IA-64, we want to setup the VM area for the register backing * store (which grows upwards) and install the gateway page which is * used for signal trampolines, etc. */ void ia64_init_addr_space (void) { struct vm_area_struct *vma; ia64_set_rbs_bot(); /* * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore * the problem. When the process attempts to write to the register backing store * for the first time, it will get a SEGFAULT in this case. */ vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL); if (vma) { memset(vma, 0, sizeof(*vma)); vma->vm_mm = current->mm; vma->vm_start = current->thread.rbs_bot & PAGE_MASK; vma->vm_end = vma->vm_start + PAGE_SIZE; vma->vm_page_prot = protection_map[VM_DATA_DEFAULT_FLAGS & 0x7]; vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT; down_write(¤t->mm->mmap_sem); if (insert_vm_struct(current->mm, vma)) { up_write(¤t->mm->mmap_sem); kmem_cache_free(vm_area_cachep, vma); return; } up_write(¤t->mm->mmap_sem); } /* map NaT-page at address zero to speed up speculative dereferencing of NULL: */ if (!(current->personality & MMAP_PAGE_ZERO)) { vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL); if (vma) { memset(vma, 0, sizeof(*vma)); vma->vm_mm = current->mm; vma->vm_end = PAGE_SIZE; vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT); vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO | VM_RESERVED; down_write(¤t->mm->mmap_sem); if (insert_vm_struct(current->mm, vma)) { up_write(¤t->mm->mmap_sem); kmem_cache_free(vm_area_cachep, vma); return; } up_write(¤t->mm->mmap_sem); } } } void free_initmem (void) { unsigned long addr, eaddr; addr = (unsigned long) ia64_imva(__init_begin); eaddr = (unsigned long) ia64_imva(__init_end); while (addr < eaddr) { ClearPageReserved(virt_to_page(addr)); set_page_count(virt_to_page(addr), 1); free_page(addr); ++totalram_pages; addr += PAGE_SIZE; } printk(KERN_INFO "Freeing unused kernel memory: %ldkB freed\n", (__init_end - __init_begin) >> 10); } void free_initrd_mem (unsigned long start, unsigned long end) { struct page *page; /* * EFI uses 4KB pages while the kernel can use 4KB or bigger. * Thus EFI and the kernel may have different page sizes. It is * therefore possible to have the initrd share the same page as * the end of the kernel (given current setup). * * To avoid freeing/using the wrong page (kernel sized) we: * - align up the beginning of initrd * - align down the end of initrd * * | | * |=============| a000 * | | * | | * | | 9000 * |/////////////| * |/////////////| * |=============| 8000 * |///INITRD////| * |/////////////| * |/////////////| 7000 * | | * |KKKKKKKKKKKKK| * |=============| 6000 * |KKKKKKKKKKKKK| * |KKKKKKKKKKKKK| * K=kernel using 8KB pages * * In this example, we must free page 8000 ONLY. So we must align up * initrd_start and keep initrd_end as is. */ start = PAGE_ALIGN(start); end = end & PAGE_MASK; if (start < end) printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10); for (; start < end; start += PAGE_SIZE) { if (!virt_addr_valid(start)) continue; page = virt_to_page(start); ClearPageReserved(page); set_page_count(page, 1); free_page(start); ++totalram_pages; } } /* * This installs a clean page in the kernel's page table. */ struct page * put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot) { pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t *pte; if (!PageReserved(page)) printk(KERN_ERR "put_kernel_page: page at 0x%p not in reserved memory\n", page_address(page)); pgd = pgd_offset_k(address); /* note: this is NOT pgd_offset()! */ spin_lock(&init_mm.page_table_lock); { pud = pud_alloc(&init_mm, pgd, address); if (!pud) goto out; pmd = pmd_alloc(&init_mm, pud, address); if (!pmd) goto out; pte = pte_alloc_map(&init_mm, pmd, address); if (!pte) goto out; if (!pte_none(*pte)) { pte_unmap(pte); goto out; } set_pte(pte, mk_pte(page, pgprot)); pte_unmap(pte); } out: spin_unlock(&init_mm.page_table_lock); /* no need for flush_tlb */ return page; } static void setup_gate (void) { struct page *page; /* * Map the gate page twice: once read-only to export the ELF * headers etc. and once execute-only page to enable * privilege-promotion via "epc": */ page = virt_to_page(ia64_imva(__start_gate_section)); put_kernel_page(page, GATE_ADDR, PAGE_READONLY); #ifdef HAVE_BUGGY_SEGREL page = virt_to_page(ia64_imva(__start_gate_section + PAGE_SIZE)); put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE); #else put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE); /* Fill in the holes (if any) with read-only zero pages: */ { unsigned long addr; for (addr = GATE_ADDR + PAGE_SIZE; addr < GATE_ADDR + PERCPU_PAGE_SIZE; addr += PAGE_SIZE) { put_kernel_page(ZERO_PAGE(0), addr, PAGE_READONLY); put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE, PAGE_READONLY); } } #endif ia64_patch_gate(); } void __devinit ia64_mmu_init (void *my_cpu_data) { unsigned long psr, pta, impl_va_bits; extern void __devinit tlb_init (void); #ifdef CONFIG_DISABLE_VHPT # define VHPT_ENABLE_BIT 0 #else # define VHPT_ENABLE_BIT 1 #endif /* Pin mapping for percpu area into TLB */ psr = ia64_clear_ic(); ia64_itr(0x2, IA64_TR_PERCPU_DATA, PERCPU_ADDR, pte_val(pfn_pte(__pa(my_cpu_data) >> PAGE_SHIFT, PAGE_KERNEL)), PERCPU_PAGE_SHIFT); ia64_set_psr(psr); ia64_srlz_i(); /* * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped * address space. The IA-64 architecture guarantees that at least 50 bits of * virtual address space are implemented but if we pick a large enough page size * (e.g., 64KB), the mapped address space is big enough that it will overlap with * VMLPT. I assume that once we run on machines big enough to warrant 64KB pages, * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a * problem in practice. Alternatively, we could truncate the top of the mapped * address space to not permit mappings that would overlap with the VMLPT. * --davidm 00/12/06 */ # define pte_bits 3 # define mapped_space_bits (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT) /* * The virtual page table has to cover the entire implemented address space within * a region even though not all of this space may be mappable. The reason for * this is that the Access bit and Dirty bit fault handlers perform * non-speculative accesses to the virtual page table, so the address range of the * virtual page table itself needs to be covered by virtual page table. */ # define vmlpt_bits (impl_va_bits - PAGE_SHIFT + pte_bits) # define POW2(n) (1ULL << (n)) impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61))); if (impl_va_bits < 51 || impl_va_bits > 61) panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1); /* * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need, * which must fit into "vmlpt_bits - pte_bits" slots. Second half of * the test makes sure that our mapped space doesn't overlap the * unimplemented hole in the middle of the region. */ if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) || (mapped_space_bits > impl_va_bits - 1)) panic("Cannot build a big enough virtual-linear page table" " to cover mapped address space.\n" " Try using a smaller page size.\n"); /* place the VMLPT at the end of each page-table mapped region: */ pta = POW2(61) - POW2(vmlpt_bits); /* * Set the (virtually mapped linear) page table address. Bit * 8 selects between the short and long format, bits 2-7 the * size of the table, and bit 0 whether the VHPT walker is * enabled. */ ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT); ia64_tlb_init(); #ifdef CONFIG_HUGETLB_PAGE ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2); ia64_srlz_d(); #endif } #ifdef CONFIG_VIRTUAL_MEM_MAP int create_mem_map_page_table (u64 start, u64 end, void *arg) { unsigned long address, start_page, end_page; struct page *map_start, *map_end; int node; pgd_t *pgd; pud_t *pud; pmd_t *pmd; pte_t *pte; map_start = vmem_map + (__pa(start) >> PAGE_SHIFT); map_end = vmem_map + (__pa(end) >> PAGE_SHIFT); start_page = (unsigned long) map_start & PAGE_MASK; end_page = PAGE_ALIGN((unsigned long) map_end); node = paddr_to_nid(__pa(start)); for (address = start_page; address < end_page; address += PAGE_SIZE) { pgd = pgd_offset_k(address); if (pgd_none(*pgd)) pgd_populate(&init_mm, pgd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE)); pud = pud_offset(pgd, address); if (pud_none(*pud)) pud_populate(&init_mm, pud, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE)); pmd = pmd_offset(pud, address); if (pmd_none(*pmd)) pmd_populate_kernel(&init_mm, pmd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE)); pte = pte_offset_kernel(pmd, address); if (pte_none(*pte)) set_pte(pte, pfn_pte(__pa(alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE)) >> PAGE_SHIFT, PAGE_KERNEL)); } return 0; } struct memmap_init_callback_data { struct page *start; struct page *end; int nid; unsigned long zone; }; static int virtual_memmap_init (u64 start, u64 end, void *arg) { struct memmap_init_callback_data *args; struct page *map_start, *map_end; args = (struct memmap_init_callback_data *) arg; map_start = vmem_map + (__pa(start) >> PAGE_SHIFT); map_end = vmem_map + (__pa(end) >> PAGE_SHIFT); if (map_start < args->start) map_start = args->start; if (map_end > args->end) map_end = args->end; /* * We have to initialize "out of bounds" struct page elements that fit completely * on the same pages that were allocated for the "in bounds" elements because they * may be referenced later (and found to be "reserved"). */ map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1)) / sizeof(struct page); map_end += ((PAGE_ALIGN((unsigned long) map_end) - (unsigned long) map_end) / sizeof(struct page)); if (map_start < map_end) memmap_init_zone((unsigned long)(map_end - map_start), args->nid, args->zone, page_to_pfn(map_start)); return 0; } void memmap_init (unsigned long size, int nid, unsigned long zone, unsigned long start_pfn) { if (!vmem_map) memmap_init_zone(size, nid, zone, start_pfn); else { struct page *start; struct memmap_init_callback_data args; start = pfn_to_page(start_pfn); args.start = start; args.end = start + size; args.nid = nid; args.zone = zone; efi_memmap_walk(virtual_memmap_init, &args); } } int ia64_pfn_valid (unsigned long pfn) { char byte; struct page *pg = pfn_to_page(pfn); return (__get_user(byte, (char __user *) pg) == 0) && ((((u64)pg & PAGE_MASK) == (((u64)(pg + 1) - 1) & PAGE_MASK)) || (__get_user(byte, (char __user *) (pg + 1) - 1) == 0)); } EXPORT_SYMBOL(ia64_pfn_valid); int find_largest_hole (u64 start, u64 end, void *arg) { u64 *max_gap = arg; static u64 last_end = PAGE_OFFSET; /* NOTE: this algorithm assumes efi memmap table is ordered */ if (*max_gap < (start - last_end)) *max_gap = start - last_end; last_end = end; return 0; } #endif /* CONFIG_VIRTUAL_MEM_MAP */ static int count_reserved_pages (u64 start, u64 end, void *arg) { unsigned long num_reserved = 0; unsigned long *count = arg; for (; start < end; start += PAGE_SIZE) if (PageReserved(virt_to_page(start))) ++num_reserved; *count += num_reserved; return 0; } /* * Boot command-line option "nolwsys" can be used to disable the use of any light-weight * system call handler. When this option is in effect, all fsyscalls will end up bubbling * down into the kernel and calling the normal (heavy-weight) syscall handler. This is * useful for performance testing, but conceivably could also come in handy for debugging * purposes. */ static int nolwsys; static int __init nolwsys_setup (char *s) { nolwsys = 1; return 1; } __setup("nolwsys", nolwsys_setup); void mem_init (void) { long reserved_pages, codesize, datasize, initsize; pg_data_t *pgdat; int i; static struct kcore_list kcore_mem, kcore_vmem, kcore_kernel; BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE); BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE); BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE); #ifdef CONFIG_PCI /* * This needs to be called _after_ the command line has been parsed but _before_ * any drivers that may need the PCI DMA interface are initialized or bootmem has * been freed. */ platform_dma_init(); #endif #ifdef CONFIG_FLATMEM if (!mem_map) BUG(); max_mapnr = max_low_pfn; #endif high_memory = __va(max_low_pfn * PAGE_SIZE); kclist_add(&kcore_mem, __va(0), max_low_pfn * PAGE_SIZE); kclist_add(&kcore_vmem, (void *)VMALLOC_START, VMALLOC_END-VMALLOC_START); kclist_add(&kcore_kernel, _stext, _end - _stext); for_each_pgdat(pgdat) if (pgdat->bdata->node_bootmem_map) totalram_pages += free_all_bootmem_node(pgdat); reserved_pages = 0; efi_memmap_walk(count_reserved_pages, &reserved_pages); codesize = (unsigned long) _etext - (unsigned long) _stext; datasize = (unsigned long) _edata - (unsigned long) _etext; initsize = (unsigned long) __init_end - (unsigned long) __init_begin; printk(KERN_INFO "Memory: %luk/%luk available (%luk code, %luk reserved, " "%luk data, %luk init)\n", (unsigned long) nr_free_pages() << (PAGE_SHIFT - 10), num_physpages << (PAGE_SHIFT - 10), codesize >> 10, reserved_pages << (PAGE_SHIFT - 10), datasize >> 10, initsize >> 10); /* * For fsyscall entrpoints with no light-weight handler, use the ordinary * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry * code can tell them apart. */ for (i = 0; i < NR_syscalls; ++i) { extern unsigned long fsyscall_table[NR_syscalls]; extern unsigned long sys_call_table[NR_syscalls]; if (!fsyscall_table[i] || nolwsys) fsyscall_table[i] = sys_call_table[i] | 1; } setup_gate(); #ifdef CONFIG_IA32_SUPPORT ia32_mem_init(); #endif }