2 * Initialize MMU support.
4 * Copyright (C) 1998-2003 Hewlett-Packard Co
5 * David Mosberger-Tang <davidm@hpl.hp.com>
7 #include <linux/kernel.h>
8 #include <linux/init.h>
10 #include <linux/bootmem.h>
11 #include <linux/efi.h>
12 #include <linux/elf.h>
14 #include <linux/mmzone.h>
15 #include <linux/module.h>
16 #include <linux/personality.h>
17 #include <linux/reboot.h>
18 #include <linux/slab.h>
19 #include <linux/swap.h>
20 #include <linux/proc_fs.h>
21 #include <linux/bitops.h>
22 #include <linux/kexec.h>
27 #include <asm/machvec.h>
29 #include <asm/patch.h>
30 #include <asm/pgalloc.h>
32 #include <asm/sections.h>
33 #include <asm/system.h>
35 #include <asm/uaccess.h>
36 #include <asm/unistd.h>
39 DEFINE_PER_CPU(struct mmu_gather
, mmu_gathers
);
41 extern void ia64_tlb_init (void);
43 unsigned long MAX_DMA_ADDRESS
= PAGE_OFFSET
+ 0x100000000UL
;
45 #ifdef CONFIG_VIRTUAL_MEM_MAP
46 unsigned long vmalloc_end
= VMALLOC_END_INIT
;
47 EXPORT_SYMBOL(vmalloc_end
);
48 struct page
*vmem_map
;
49 EXPORT_SYMBOL(vmem_map
);
52 struct page
*zero_page_memmap_ptr
; /* map entry for zero page */
53 EXPORT_SYMBOL(zero_page_memmap_ptr
);
56 __ia64_sync_icache_dcache (pte_t pte
)
62 addr
= (unsigned long) page_address(page
);
64 if (test_bit(PG_arch_1
, &page
->flags
))
65 return; /* i-cache is already coherent with d-cache */
67 flush_icache_range(addr
, addr
+ (PAGE_SIZE
<< compound_order(page
)));
68 set_bit(PG_arch_1
, &page
->flags
); /* mark page as clean */
72 * Since DMA is i-cache coherent, any (complete) pages that were written via
73 * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
74 * flush them when they get mapped into an executable vm-area.
77 dma_mark_clean(void *addr
, size_t size
)
79 unsigned long pg_addr
, end
;
81 pg_addr
= PAGE_ALIGN((unsigned long) addr
);
82 end
= (unsigned long) addr
+ size
;
83 while (pg_addr
+ PAGE_SIZE
<= end
) {
84 struct page
*page
= virt_to_page(pg_addr
);
85 set_bit(PG_arch_1
, &page
->flags
);
91 ia64_set_rbs_bot (void)
93 unsigned long stack_size
= current
->signal
->rlim
[RLIMIT_STACK
].rlim_max
& -16;
95 if (stack_size
> MAX_USER_STACK_SIZE
)
96 stack_size
= MAX_USER_STACK_SIZE
;
97 current
->thread
.rbs_bot
= PAGE_ALIGN(current
->mm
->start_stack
- stack_size
);
101 * This performs some platform-dependent address space initialization.
102 * On IA-64, we want to setup the VM area for the register backing
103 * store (which grows upwards) and install the gateway page which is
104 * used for signal trampolines, etc.
107 ia64_init_addr_space (void)
109 struct vm_area_struct
*vma
;
114 * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore
115 * the problem. When the process attempts to write to the register backing store
116 * for the first time, it will get a SEGFAULT in this case.
118 vma
= kmem_cache_zalloc(vm_area_cachep
, GFP_KERNEL
);
120 vma
->vm_mm
= current
->mm
;
121 vma
->vm_start
= current
->thread
.rbs_bot
& PAGE_MASK
;
122 vma
->vm_end
= vma
->vm_start
+ PAGE_SIZE
;
123 vma
->vm_flags
= VM_DATA_DEFAULT_FLAGS
|VM_GROWSUP
|VM_ACCOUNT
;
124 vma
->vm_page_prot
= vm_get_page_prot(vma
->vm_flags
);
125 down_write(¤t
->mm
->mmap_sem
);
126 if (insert_vm_struct(current
->mm
, vma
)) {
127 up_write(¤t
->mm
->mmap_sem
);
128 kmem_cache_free(vm_area_cachep
, vma
);
131 up_write(¤t
->mm
->mmap_sem
);
134 /* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
135 if (!(current
->personality
& MMAP_PAGE_ZERO
)) {
136 vma
= kmem_cache_zalloc(vm_area_cachep
, GFP_KERNEL
);
138 vma
->vm_mm
= current
->mm
;
139 vma
->vm_end
= PAGE_SIZE
;
140 vma
->vm_page_prot
= __pgprot(pgprot_val(PAGE_READONLY
) | _PAGE_MA_NAT
);
141 vma
->vm_flags
= VM_READ
| VM_MAYREAD
| VM_IO
| VM_RESERVED
;
142 down_write(¤t
->mm
->mmap_sem
);
143 if (insert_vm_struct(current
->mm
, vma
)) {
144 up_write(¤t
->mm
->mmap_sem
);
145 kmem_cache_free(vm_area_cachep
, vma
);
148 up_write(¤t
->mm
->mmap_sem
);
156 unsigned long addr
, eaddr
;
158 addr
= (unsigned long) ia64_imva(__init_begin
);
159 eaddr
= (unsigned long) ia64_imva(__init_end
);
160 while (addr
< eaddr
) {
161 ClearPageReserved(virt_to_page(addr
));
162 init_page_count(virt_to_page(addr
));
167 printk(KERN_INFO
"Freeing unused kernel memory: %ldkB freed\n",
168 (__init_end
- __init_begin
) >> 10);
172 free_initrd_mem (unsigned long start
, unsigned long end
)
176 * EFI uses 4KB pages while the kernel can use 4KB or bigger.
177 * Thus EFI and the kernel may have different page sizes. It is
178 * therefore possible to have the initrd share the same page as
179 * the end of the kernel (given current setup).
181 * To avoid freeing/using the wrong page (kernel sized) we:
182 * - align up the beginning of initrd
183 * - align down the end of initrd
186 * |=============| a000
192 * |=============| 8000
195 * |/////////////| 7000
198 * |=============| 6000
201 * K=kernel using 8KB pages
203 * In this example, we must free page 8000 ONLY. So we must align up
204 * initrd_start and keep initrd_end as is.
206 start
= PAGE_ALIGN(start
);
207 end
= end
& PAGE_MASK
;
210 printk(KERN_INFO
"Freeing initrd memory: %ldkB freed\n", (end
- start
) >> 10);
212 for (; start
< end
; start
+= PAGE_SIZE
) {
213 if (!virt_addr_valid(start
))
215 page
= virt_to_page(start
);
216 ClearPageReserved(page
);
217 init_page_count(page
);
224 * This installs a clean page in the kernel's page table.
226 static struct page
* __init
227 put_kernel_page (struct page
*page
, unsigned long address
, pgprot_t pgprot
)
234 if (!PageReserved(page
))
235 printk(KERN_ERR
"put_kernel_page: page at 0x%p not in reserved memory\n",
238 pgd
= pgd_offset_k(address
); /* note: this is NOT pgd_offset()! */
241 pud
= pud_alloc(&init_mm
, pgd
, address
);
244 pmd
= pmd_alloc(&init_mm
, pud
, address
);
247 pte
= pte_alloc_kernel(pmd
, address
);
252 set_pte(pte
, mk_pte(page
, pgprot
));
255 /* no need for flush_tlb */
265 * Map the gate page twice: once read-only to export the ELF
266 * headers etc. and once execute-only page to enable
267 * privilege-promotion via "epc":
269 page
= virt_to_page(ia64_imva(__start_gate_section
));
270 put_kernel_page(page
, GATE_ADDR
, PAGE_READONLY
);
271 #ifdef HAVE_BUGGY_SEGREL
272 page
= virt_to_page(ia64_imva(__start_gate_section
+ PAGE_SIZE
));
273 put_kernel_page(page
, GATE_ADDR
+ PAGE_SIZE
, PAGE_GATE
);
275 put_kernel_page(page
, GATE_ADDR
+ PERCPU_PAGE_SIZE
, PAGE_GATE
);
276 /* Fill in the holes (if any) with read-only zero pages: */
280 for (addr
= GATE_ADDR
+ PAGE_SIZE
;
281 addr
< GATE_ADDR
+ PERCPU_PAGE_SIZE
;
284 put_kernel_page(ZERO_PAGE(0), addr
,
286 put_kernel_page(ZERO_PAGE(0), addr
+ PERCPU_PAGE_SIZE
,
295 ia64_mmu_init (void *my_cpu_data
)
297 unsigned long pta
, impl_va_bits
;
298 extern void __devinit
tlb_init (void);
300 #ifdef CONFIG_DISABLE_VHPT
301 # define VHPT_ENABLE_BIT 0
303 # define VHPT_ENABLE_BIT 1
307 * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
308 * address space. The IA-64 architecture guarantees that at least 50 bits of
309 * virtual address space are implemented but if we pick a large enough page size
310 * (e.g., 64KB), the mapped address space is big enough that it will overlap with
311 * VMLPT. I assume that once we run on machines big enough to warrant 64KB pages,
312 * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
313 * problem in practice. Alternatively, we could truncate the top of the mapped
314 * address space to not permit mappings that would overlap with the VMLPT.
318 # define mapped_space_bits (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
320 * The virtual page table has to cover the entire implemented address space within
321 * a region even though not all of this space may be mappable. The reason for
322 * this is that the Access bit and Dirty bit fault handlers perform
323 * non-speculative accesses to the virtual page table, so the address range of the
324 * virtual page table itself needs to be covered by virtual page table.
326 # define vmlpt_bits (impl_va_bits - PAGE_SHIFT + pte_bits)
327 # define POW2(n) (1ULL << (n))
329 impl_va_bits
= ffz(~(local_cpu_data
->unimpl_va_mask
| (7UL << 61)));
331 if (impl_va_bits
< 51 || impl_va_bits
> 61)
332 panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits
- 1);
334 * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
335 * which must fit into "vmlpt_bits - pte_bits" slots. Second half of
336 * the test makes sure that our mapped space doesn't overlap the
337 * unimplemented hole in the middle of the region.
339 if ((mapped_space_bits
- PAGE_SHIFT
> vmlpt_bits
- pte_bits
) ||
340 (mapped_space_bits
> impl_va_bits
- 1))
341 panic("Cannot build a big enough virtual-linear page table"
342 " to cover mapped address space.\n"
343 " Try using a smaller page size.\n");
346 /* place the VMLPT at the end of each page-table mapped region: */
347 pta
= POW2(61) - POW2(vmlpt_bits
);
350 * Set the (virtually mapped linear) page table address. Bit
351 * 8 selects between the short and long format, bits 2-7 the
352 * size of the table, and bit 0 whether the VHPT walker is
355 ia64_set_pta(pta
| (0 << 8) | (vmlpt_bits
<< 2) | VHPT_ENABLE_BIT
);
359 #ifdef CONFIG_HUGETLB_PAGE
360 ia64_set_rr(HPAGE_REGION_BASE
, HPAGE_SHIFT
<< 2);
365 #ifdef CONFIG_VIRTUAL_MEM_MAP
366 int vmemmap_find_next_valid_pfn(int node
, int i
)
368 unsigned long end_address
, hole_next_pfn
;
369 unsigned long stop_address
;
370 pg_data_t
*pgdat
= NODE_DATA(node
);
372 end_address
= (unsigned long) &vmem_map
[pgdat
->node_start_pfn
+ i
];
373 end_address
= PAGE_ALIGN(end_address
);
375 stop_address
= (unsigned long) &vmem_map
[
376 pgdat
->node_start_pfn
+ pgdat
->node_spanned_pages
];
384 pgd
= pgd_offset_k(end_address
);
385 if (pgd_none(*pgd
)) {
386 end_address
+= PGDIR_SIZE
;
390 pud
= pud_offset(pgd
, end_address
);
391 if (pud_none(*pud
)) {
392 end_address
+= PUD_SIZE
;
396 pmd
= pmd_offset(pud
, end_address
);
397 if (pmd_none(*pmd
)) {
398 end_address
+= PMD_SIZE
;
402 pte
= pte_offset_kernel(pmd
, end_address
);
404 if (pte_none(*pte
)) {
405 end_address
+= PAGE_SIZE
;
407 if ((end_address
< stop_address
) &&
408 (end_address
!= ALIGN(end_address
, 1UL << PMD_SHIFT
)))
412 /* Found next valid vmem_map page */
414 } while (end_address
< stop_address
);
416 end_address
= min(end_address
, stop_address
);
417 end_address
= end_address
- (unsigned long) vmem_map
+ sizeof(struct page
) - 1;
418 hole_next_pfn
= end_address
/ sizeof(struct page
);
419 return hole_next_pfn
- pgdat
->node_start_pfn
;
423 create_mem_map_page_table (u64 start
, u64 end
, void *arg
)
425 unsigned long address
, start_page
, end_page
;
426 struct page
*map_start
, *map_end
;
433 map_start
= vmem_map
+ (__pa(start
) >> PAGE_SHIFT
);
434 map_end
= vmem_map
+ (__pa(end
) >> PAGE_SHIFT
);
436 start_page
= (unsigned long) map_start
& PAGE_MASK
;
437 end_page
= PAGE_ALIGN((unsigned long) map_end
);
438 node
= paddr_to_nid(__pa(start
));
440 for (address
= start_page
; address
< end_page
; address
+= PAGE_SIZE
) {
441 pgd
= pgd_offset_k(address
);
443 pgd_populate(&init_mm
, pgd
, alloc_bootmem_pages_node(NODE_DATA(node
), PAGE_SIZE
));
444 pud
= pud_offset(pgd
, address
);
447 pud_populate(&init_mm
, pud
, alloc_bootmem_pages_node(NODE_DATA(node
), PAGE_SIZE
));
448 pmd
= pmd_offset(pud
, address
);
451 pmd_populate_kernel(&init_mm
, pmd
, alloc_bootmem_pages_node(NODE_DATA(node
), PAGE_SIZE
));
452 pte
= pte_offset_kernel(pmd
, address
);
455 set_pte(pte
, pfn_pte(__pa(alloc_bootmem_pages_node(NODE_DATA(node
), PAGE_SIZE
)) >> PAGE_SHIFT
,
461 struct memmap_init_callback_data
{
469 virtual_memmap_init (u64 start
, u64 end
, void *arg
)
471 struct memmap_init_callback_data
*args
;
472 struct page
*map_start
, *map_end
;
474 args
= (struct memmap_init_callback_data
*) arg
;
475 map_start
= vmem_map
+ (__pa(start
) >> PAGE_SHIFT
);
476 map_end
= vmem_map
+ (__pa(end
) >> PAGE_SHIFT
);
478 if (map_start
< args
->start
)
479 map_start
= args
->start
;
480 if (map_end
> args
->end
)
484 * We have to initialize "out of bounds" struct page elements that fit completely
485 * on the same pages that were allocated for the "in bounds" elements because they
486 * may be referenced later (and found to be "reserved").
488 map_start
-= ((unsigned long) map_start
& (PAGE_SIZE
- 1)) / sizeof(struct page
);
489 map_end
+= ((PAGE_ALIGN((unsigned long) map_end
) - (unsigned long) map_end
)
490 / sizeof(struct page
));
492 if (map_start
< map_end
)
493 memmap_init_zone((unsigned long)(map_end
- map_start
),
494 args
->nid
, args
->zone
, page_to_pfn(map_start
),
500 memmap_init (unsigned long size
, int nid
, unsigned long zone
,
501 unsigned long start_pfn
)
504 memmap_init_zone(size
, nid
, zone
, start_pfn
, MEMMAP_EARLY
);
507 struct memmap_init_callback_data args
;
509 start
= pfn_to_page(start_pfn
);
511 args
.end
= start
+ size
;
515 efi_memmap_walk(virtual_memmap_init
, &args
);
520 ia64_pfn_valid (unsigned long pfn
)
523 struct page
*pg
= pfn_to_page(pfn
);
525 return (__get_user(byte
, (char __user
*) pg
) == 0)
526 && ((((u64
)pg
& PAGE_MASK
) == (((u64
)(pg
+ 1) - 1) & PAGE_MASK
))
527 || (__get_user(byte
, (char __user
*) (pg
+ 1) - 1) == 0));
529 EXPORT_SYMBOL(ia64_pfn_valid
);
532 find_largest_hole (u64 start
, u64 end
, void *arg
)
536 static u64 last_end
= PAGE_OFFSET
;
538 /* NOTE: this algorithm assumes efi memmap table is ordered */
540 if (*max_gap
< (start
- last_end
))
541 *max_gap
= start
- last_end
;
546 #endif /* CONFIG_VIRTUAL_MEM_MAP */
549 register_active_ranges(u64 start
, u64 len
, int nid
)
551 u64 end
= start
+ len
;
554 if (start
> crashk_res
.start
&& start
< crashk_res
.end
)
555 start
= crashk_res
.end
;
556 if (end
> crashk_res
.start
&& end
< crashk_res
.end
)
557 end
= crashk_res
.start
;
561 add_active_range(nid
, __pa(start
) >> PAGE_SHIFT
,
562 __pa(end
) >> PAGE_SHIFT
);
567 count_reserved_pages (u64 start
, u64 end
, void *arg
)
569 unsigned long num_reserved
= 0;
570 unsigned long *count
= arg
;
572 for (; start
< end
; start
+= PAGE_SIZE
)
573 if (PageReserved(virt_to_page(start
)))
575 *count
+= num_reserved
;
580 find_max_min_low_pfn (unsigned long start
, unsigned long end
, void *arg
)
582 unsigned long pfn_start
, pfn_end
;
583 #ifdef CONFIG_FLATMEM
584 pfn_start
= (PAGE_ALIGN(__pa(start
))) >> PAGE_SHIFT
;
585 pfn_end
= (PAGE_ALIGN(__pa(end
- 1))) >> PAGE_SHIFT
;
587 pfn_start
= GRANULEROUNDDOWN(__pa(start
)) >> PAGE_SHIFT
;
588 pfn_end
= GRANULEROUNDUP(__pa(end
- 1)) >> PAGE_SHIFT
;
590 min_low_pfn
= min(min_low_pfn
, pfn_start
);
591 max_low_pfn
= max(max_low_pfn
, pfn_end
);
596 * Boot command-line option "nolwsys" can be used to disable the use of any light-weight
597 * system call handler. When this option is in effect, all fsyscalls will end up bubbling
598 * down into the kernel and calling the normal (heavy-weight) syscall handler. This is
599 * useful for performance testing, but conceivably could also come in handy for debugging
603 static int nolwsys __initdata
;
606 nolwsys_setup (char *s
)
612 __setup("nolwsys", nolwsys_setup
);
617 long reserved_pages
, codesize
, datasize
, initsize
;
620 static struct kcore_list kcore_mem
, kcore_vmem
, kcore_kernel
;
622 BUG_ON(PTRS_PER_PGD
* sizeof(pgd_t
) != PAGE_SIZE
);
623 BUG_ON(PTRS_PER_PMD
* sizeof(pmd_t
) != PAGE_SIZE
);
624 BUG_ON(PTRS_PER_PTE
* sizeof(pte_t
) != PAGE_SIZE
);
628 * This needs to be called _after_ the command line has been parsed but _before_
629 * any drivers that may need the PCI DMA interface are initialized or bootmem has
635 #ifdef CONFIG_FLATMEM
638 max_mapnr
= max_low_pfn
;
641 high_memory
= __va(max_low_pfn
* PAGE_SIZE
);
643 kclist_add(&kcore_mem
, __va(0), max_low_pfn
* PAGE_SIZE
);
644 kclist_add(&kcore_vmem
, (void *)VMALLOC_START
, VMALLOC_END
-VMALLOC_START
);
645 kclist_add(&kcore_kernel
, _stext
, _end
- _stext
);
647 for_each_online_pgdat(pgdat
)
648 if (pgdat
->bdata
->node_bootmem_map
)
649 totalram_pages
+= free_all_bootmem_node(pgdat
);
652 efi_memmap_walk(count_reserved_pages
, &reserved_pages
);
654 codesize
= (unsigned long) _etext
- (unsigned long) _stext
;
655 datasize
= (unsigned long) _edata
- (unsigned long) _etext
;
656 initsize
= (unsigned long) __init_end
- (unsigned long) __init_begin
;
658 printk(KERN_INFO
"Memory: %luk/%luk available (%luk code, %luk reserved, "
659 "%luk data, %luk init)\n", (unsigned long) nr_free_pages() << (PAGE_SHIFT
- 10),
660 num_physpages
<< (PAGE_SHIFT
- 10), codesize
>> 10,
661 reserved_pages
<< (PAGE_SHIFT
- 10), datasize
>> 10, initsize
>> 10);
665 * For fsyscall entrpoints with no light-weight handler, use the ordinary
666 * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry
667 * code can tell them apart.
669 for (i
= 0; i
< NR_syscalls
; ++i
) {
670 extern unsigned long fsyscall_table
[NR_syscalls
];
671 extern unsigned long sys_call_table
[NR_syscalls
];
673 if (!fsyscall_table
[i
] || nolwsys
)
674 fsyscall_table
[i
] = sys_call_table
[i
] | 1;
678 #ifdef CONFIG_IA32_SUPPORT
683 #ifdef CONFIG_MEMORY_HOTPLUG
684 int arch_add_memory(int nid
, u64 start
, u64 size
)
688 unsigned long start_pfn
= start
>> PAGE_SHIFT
;
689 unsigned long nr_pages
= size
>> PAGE_SHIFT
;
692 pgdat
= NODE_DATA(nid
);
694 zone
= pgdat
->node_zones
+ ZONE_NORMAL
;
695 ret
= __add_pages(zone
, start_pfn
, nr_pages
);
698 printk("%s: Problem encountered in __add_pages() as ret=%d\n",
706 * Even when CONFIG_IA32_SUPPORT is not enabled it is
707 * useful to have the Linux/x86 domain registered to
708 * avoid an attempted module load when emulators call
709 * personality(PER_LINUX32). This saves several milliseconds
712 static struct exec_domain ia32_exec_domain
;
715 per_linux32_init(void)
717 ia32_exec_domain
.name
= "Linux/x86";
718 ia32_exec_domain
.handler
= NULL
;
719 ia32_exec_domain
.pers_low
= PER_LINUX32
;
720 ia32_exec_domain
.pers_high
= PER_LINUX32
;
721 ia32_exec_domain
.signal_map
= default_exec_domain
.signal_map
;
722 ia32_exec_domain
.signal_invmap
= default_exec_domain
.signal_invmap
;
723 register_exec_domain(&ia32_exec_domain
);
728 __initcall(per_linux32_init
);