2 * Re-map IO memory to kernel address space so that we can access it.
3 * This is needed for high PCI addresses that aren't mapped in the
4 * 640k-1MB IO memory area on PC's
6 * (C) Copyright 1995 1996 Linus Torvalds
9 #include <linux/bootmem.h>
10 #include <linux/init.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/vmalloc.h>
15 #include <linux/mmiotrace.h>
17 #include <asm/cacheflush.h>
19 #include <asm/fixmap.h>
20 #include <asm/pgtable.h>
21 #include <asm/tlbflush.h>
22 #include <asm/pgalloc.h>
27 unsigned long __phys_addr(unsigned long x
)
29 if (x
>= __START_KERNEL_map
)
30 return x
- __START_KERNEL_map
+ phys_base
;
31 return x
- PAGE_OFFSET
;
33 EXPORT_SYMBOL(__phys_addr
);
35 static inline int phys_addr_valid(unsigned long addr
)
37 return addr
< (1UL << boot_cpu_data
.x86_phys_bits
);
42 static inline int phys_addr_valid(unsigned long addr
)
49 int page_is_ram(unsigned long pagenr
)
51 resource_size_t addr
, end
;
55 * A special case is the first 4Kb of memory;
56 * This is a BIOS owned area, not kernel ram, but generally
57 * not listed as such in the E820 table.
63 * Second special case: Some BIOSen report the PC BIOS
64 * area (640->1Mb) as ram even though it is not.
66 if (pagenr
>= (BIOS_BEGIN
>> PAGE_SHIFT
) &&
67 pagenr
< (BIOS_END
>> PAGE_SHIFT
))
70 for (i
= 0; i
< e820
.nr_map
; i
++) {
74 if (e820
.map
[i
].type
!= E820_RAM
)
76 addr
= (e820
.map
[i
].addr
+ PAGE_SIZE
-1) >> PAGE_SHIFT
;
77 end
= (e820
.map
[i
].addr
+ e820
.map
[i
].size
) >> PAGE_SHIFT
;
80 if ((pagenr
>= addr
) && (pagenr
< end
))
87 * Fix up the linear direct mapping of the kernel to avoid cache attribute
90 int ioremap_change_attr(unsigned long vaddr
, unsigned long size
,
91 unsigned long prot_val
)
93 unsigned long nrpages
= size
>> PAGE_SHIFT
;
99 err
= _set_memory_uc(vaddr
, nrpages
);
102 err
= _set_memory_wc(vaddr
, nrpages
);
105 err
= _set_memory_wb(vaddr
, nrpages
);
113 * Remap an arbitrary physical address space into the kernel virtual
114 * address space. Needed when the kernel wants to access high addresses
117 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
118 * have to convert them into an offset in a page-aligned mapping, but the
119 * caller shouldn't need to know that small detail.
121 static void __iomem
*__ioremap_caller(resource_size_t phys_addr
,
122 unsigned long size
, unsigned long prot_val
, void *caller
)
124 unsigned long pfn
, offset
, vaddr
;
125 resource_size_t last_addr
;
126 const resource_size_t unaligned_phys_addr
= phys_addr
;
127 const unsigned long unaligned_size
= size
;
128 struct vm_struct
*area
;
129 unsigned long new_prot_val
;
132 void __iomem
*ret_addr
;
134 /* Don't allow wraparound or zero size */
135 last_addr
= phys_addr
+ size
- 1;
136 if (!size
|| last_addr
< phys_addr
)
139 if (!phys_addr_valid(phys_addr
)) {
140 printk(KERN_WARNING
"ioremap: invalid physical address %llx\n",
141 (unsigned long long)phys_addr
);
147 * Don't remap the low PCI/ISA area, it's always mapped..
149 if (is_ISA_range(phys_addr
, last_addr
))
150 return (__force
void __iomem
*)phys_to_virt(phys_addr
);
153 * Don't allow anybody to remap normal RAM that we're using..
155 for (pfn
= phys_addr
>> PAGE_SHIFT
;
156 (pfn
<< PAGE_SHIFT
) < (last_addr
& PAGE_MASK
);
159 int is_ram
= page_is_ram(pfn
);
161 if (is_ram
&& pfn_valid(pfn
) && !PageReserved(pfn_to_page(pfn
)))
163 WARN_ON_ONCE(is_ram
);
167 * Mappings have to be page-aligned
169 offset
= phys_addr
& ~PAGE_MASK
;
170 phys_addr
&= PAGE_MASK
;
171 size
= PAGE_ALIGN(last_addr
+1) - phys_addr
;
173 retval
= reserve_memtype(phys_addr
, phys_addr
+ size
,
174 prot_val
, &new_prot_val
);
176 pr_debug("Warning: reserve_memtype returned %d\n", retval
);
180 if (prot_val
!= new_prot_val
) {
182 * Do not fallback to certain memory types with certain
184 * - request is uc-, return cannot be write-back
185 * - request is uc-, return cannot be write-combine
186 * - request is write-combine, return cannot be write-back
188 if ((prot_val
== _PAGE_CACHE_UC_MINUS
&&
189 (new_prot_val
== _PAGE_CACHE_WB
||
190 new_prot_val
== _PAGE_CACHE_WC
)) ||
191 (prot_val
== _PAGE_CACHE_WC
&&
192 new_prot_val
== _PAGE_CACHE_WB
)) {
194 "ioremap error for 0x%llx-0x%llx, requested 0x%lx, got 0x%lx\n",
195 (unsigned long long)phys_addr
,
196 (unsigned long long)(phys_addr
+ size
),
197 prot_val
, new_prot_val
);
198 free_memtype(phys_addr
, phys_addr
+ size
);
201 prot_val
= new_prot_val
;
207 prot
= PAGE_KERNEL_NOCACHE
;
209 case _PAGE_CACHE_UC_MINUS
:
210 prot
= PAGE_KERNEL_UC_MINUS
;
213 prot
= PAGE_KERNEL_WC
;
223 area
= get_vm_area_caller(size
, VM_IOREMAP
, caller
);
226 area
->phys_addr
= phys_addr
;
227 vaddr
= (unsigned long) area
->addr
;
228 if (ioremap_page_range(vaddr
, vaddr
+ size
, phys_addr
, prot
)) {
229 free_memtype(phys_addr
, phys_addr
+ size
);
234 if (ioremap_change_attr(vaddr
, size
, prot_val
) < 0) {
235 free_memtype(phys_addr
, phys_addr
+ size
);
240 ret_addr
= (void __iomem
*) (vaddr
+ offset
);
241 mmiotrace_ioremap(unaligned_phys_addr
, unaligned_size
, ret_addr
);
247 * ioremap_nocache - map bus memory into CPU space
248 * @offset: bus address of the memory
249 * @size: size of the resource to map
251 * ioremap_nocache performs a platform specific sequence of operations to
252 * make bus memory CPU accessible via the readb/readw/readl/writeb/
253 * writew/writel functions and the other mmio helpers. The returned
254 * address is not guaranteed to be usable directly as a virtual
257 * This version of ioremap ensures that the memory is marked uncachable
258 * on the CPU as well as honouring existing caching rules from things like
259 * the PCI bus. Note that there are other caches and buffers on many
260 * busses. In particular driver authors should read up on PCI writes
262 * It's useful if some control registers are in such an area and
263 * write combining or read caching is not desirable:
265 * Must be freed with iounmap.
267 void __iomem
*ioremap_nocache(resource_size_t phys_addr
, unsigned long size
)
270 * Ideally, this should be:
271 * pat_enabled ? _PAGE_CACHE_UC : _PAGE_CACHE_UC_MINUS;
273 * Till we fix all X drivers to use ioremap_wc(), we will use
276 unsigned long val
= _PAGE_CACHE_UC_MINUS
;
278 return __ioremap_caller(phys_addr
, size
, val
,
279 __builtin_return_address(0));
281 EXPORT_SYMBOL(ioremap_nocache
);
284 * ioremap_wc - map memory into CPU space write combined
285 * @offset: bus address of the memory
286 * @size: size of the resource to map
288 * This version of ioremap ensures that the memory is marked write combining.
289 * Write combining allows faster writes to some hardware devices.
291 * Must be freed with iounmap.
293 void __iomem
*ioremap_wc(unsigned long phys_addr
, unsigned long size
)
296 return __ioremap_caller(phys_addr
, size
, _PAGE_CACHE_WC
,
297 __builtin_return_address(0));
299 return ioremap_nocache(phys_addr
, size
);
301 EXPORT_SYMBOL(ioremap_wc
);
303 void __iomem
*ioremap_cache(resource_size_t phys_addr
, unsigned long size
)
305 return __ioremap_caller(phys_addr
, size
, _PAGE_CACHE_WB
,
306 __builtin_return_address(0));
308 EXPORT_SYMBOL(ioremap_cache
);
310 static void __iomem
*ioremap_default(resource_size_t phys_addr
,
318 * - WB for WB-able memory and no other conflicting mappings
319 * - UC_MINUS for non-WB-able memory with no other conflicting mappings
320 * - Inherit from confliting mappings otherwise
322 err
= reserve_memtype(phys_addr
, phys_addr
+ size
, -1, &flags
);
326 ret
= (void *) __ioremap_caller(phys_addr
, size
, flags
,
327 __builtin_return_address(0));
329 free_memtype(phys_addr
, phys_addr
+ size
);
330 return (void __iomem
*)ret
;
334 * iounmap - Free a IO remapping
335 * @addr: virtual address from ioremap_*
337 * Caller must ensure there is only one unmapping for the same pointer.
339 void iounmap(volatile void __iomem
*addr
)
341 struct vm_struct
*p
, *o
;
343 if ((void __force
*)addr
<= high_memory
)
347 * __ioremap special-cases the PCI/ISA range by not instantiating a
348 * vm_area and by simply returning an address into the kernel mapping
349 * of ISA space. So handle that here.
351 if ((void __force
*)addr
>= phys_to_virt(ISA_START_ADDRESS
) &&
352 (void __force
*)addr
< phys_to_virt(ISA_END_ADDRESS
))
355 addr
= (volatile void __iomem
*)
356 (PAGE_MASK
& (unsigned long __force
)addr
);
358 mmiotrace_iounmap(addr
);
360 /* Use the vm area unlocked, assuming the caller
361 ensures there isn't another iounmap for the same address
362 in parallel. Reuse of the virtual address is prevented by
363 leaving it in the global lists until we're done with it.
364 cpa takes care of the direct mappings. */
365 read_lock(&vmlist_lock
);
366 for (p
= vmlist
; p
; p
= p
->next
) {
367 if (p
->addr
== (void __force
*)addr
)
370 read_unlock(&vmlist_lock
);
373 printk(KERN_ERR
"iounmap: bad address %p\n", addr
);
378 free_memtype(p
->phys_addr
, p
->phys_addr
+ get_vm_area_size(p
));
380 /* Finally remove it */
381 o
= remove_vm_area((void __force
*)addr
);
382 BUG_ON(p
!= o
|| o
== NULL
);
385 EXPORT_SYMBOL(iounmap
);
388 * Convert a physical pointer to a virtual kernel pointer for /dev/mem
391 void *xlate_dev_mem_ptr(unsigned long phys
)
394 unsigned long start
= phys
& PAGE_MASK
;
396 /* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
397 if (page_is_ram(start
>> PAGE_SHIFT
))
400 addr
= (void __force
*)ioremap_default(start
, PAGE_SIZE
);
402 addr
= (void *)((unsigned long)addr
| (phys
& ~PAGE_MASK
));
407 void unxlate_dev_mem_ptr(unsigned long phys
, void *addr
)
409 if (page_is_ram(phys
>> PAGE_SHIFT
))
412 iounmap((void __iomem
*)((unsigned long)addr
& PAGE_MASK
));
416 int __initdata early_ioremap_debug
;
418 static int __init
early_ioremap_debug_setup(char *str
)
420 early_ioremap_debug
= 1;
424 early_param("early_ioremap_debug", early_ioremap_debug_setup
);
426 static __initdata
int after_paging_init
;
427 static pte_t bm_pte
[PAGE_SIZE
/sizeof(pte_t
)] __page_aligned_bss
;
429 static inline pmd_t
* __init
early_ioremap_pmd(unsigned long addr
)
431 /* Don't assume we're using swapper_pg_dir at this point */
432 pgd_t
*base
= __va(read_cr3());
433 pgd_t
*pgd
= &base
[pgd_index(addr
)];
434 pud_t
*pud
= pud_offset(pgd
, addr
);
435 pmd_t
*pmd
= pmd_offset(pud
, addr
);
440 static inline pte_t
* __init
early_ioremap_pte(unsigned long addr
)
442 return &bm_pte
[pte_index(addr
)];
445 void __init
early_ioremap_init(void)
449 if (early_ioremap_debug
)
450 printk(KERN_INFO
"early_ioremap_init()\n");
452 pmd
= early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN
));
453 memset(bm_pte
, 0, sizeof(bm_pte
));
454 pmd_populate_kernel(&init_mm
, pmd
, bm_pte
);
457 * The boot-ioremap range spans multiple pmds, for which
458 * we are not prepared:
460 if (pmd
!= early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END
))) {
462 printk(KERN_WARNING
"pmd %p != %p\n",
463 pmd
, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END
)));
464 printk(KERN_WARNING
"fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
465 fix_to_virt(FIX_BTMAP_BEGIN
));
466 printk(KERN_WARNING
"fix_to_virt(FIX_BTMAP_END): %08lx\n",
467 fix_to_virt(FIX_BTMAP_END
));
469 printk(KERN_WARNING
"FIX_BTMAP_END: %d\n", FIX_BTMAP_END
);
470 printk(KERN_WARNING
"FIX_BTMAP_BEGIN: %d\n",
475 void __init
early_ioremap_clear(void)
479 if (early_ioremap_debug
)
480 printk(KERN_INFO
"early_ioremap_clear()\n");
482 pmd
= early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN
));
484 paravirt_release_pte(__pa(bm_pte
) >> PAGE_SHIFT
);
488 void __init
early_ioremap_reset(void)
490 enum fixed_addresses idx
;
491 unsigned long addr
, phys
;
494 after_paging_init
= 1;
495 for (idx
= FIX_BTMAP_BEGIN
; idx
>= FIX_BTMAP_END
; idx
--) {
496 addr
= fix_to_virt(idx
);
497 pte
= early_ioremap_pte(addr
);
498 if (pte_present(*pte
)) {
499 phys
= pte_val(*pte
) & PAGE_MASK
;
500 set_fixmap(idx
, phys
);
505 static void __init
__early_set_fixmap(enum fixed_addresses idx
,
506 unsigned long phys
, pgprot_t flags
)
508 unsigned long addr
= __fix_to_virt(idx
);
511 if (idx
>= __end_of_fixed_addresses
) {
515 pte
= early_ioremap_pte(addr
);
517 if (pgprot_val(flags
))
518 set_pte(pte
, pfn_pte(phys
>> PAGE_SHIFT
, flags
));
520 pte_clear(&init_mm
, addr
, pte
);
521 __flush_tlb_one(addr
);
524 static inline void __init
early_set_fixmap(enum fixed_addresses idx
,
527 if (after_paging_init
)
528 set_fixmap(idx
, phys
);
530 __early_set_fixmap(idx
, phys
, PAGE_KERNEL
);
533 static inline void __init
early_clear_fixmap(enum fixed_addresses idx
)
535 if (after_paging_init
)
538 __early_set_fixmap(idx
, 0, __pgprot(0));
542 int __initdata early_ioremap_nested
;
544 static int __init
check_early_ioremap_leak(void)
546 if (!early_ioremap_nested
)
550 "Debug warning: early ioremap leak of %d areas detected.\n",
551 early_ioremap_nested
);
553 "please boot with early_ioremap_debug and report the dmesg.\n");
558 late_initcall(check_early_ioremap_leak
);
560 void __init
*early_ioremap(unsigned long phys_addr
, unsigned long size
)
562 unsigned long offset
, last_addr
;
563 unsigned int nrpages
, nesting
;
564 enum fixed_addresses idx0
, idx
;
566 WARN_ON(system_state
!= SYSTEM_BOOTING
);
568 nesting
= early_ioremap_nested
;
569 if (early_ioremap_debug
) {
570 printk(KERN_INFO
"early_ioremap(%08lx, %08lx) [%d] => ",
571 phys_addr
, size
, nesting
);
575 /* Don't allow wraparound or zero size */
576 last_addr
= phys_addr
+ size
- 1;
577 if (!size
|| last_addr
< phys_addr
) {
582 if (nesting
>= FIX_BTMAPS_NESTING
) {
586 early_ioremap_nested
++;
588 * Mappings have to be page-aligned
590 offset
= phys_addr
& ~PAGE_MASK
;
591 phys_addr
&= PAGE_MASK
;
592 size
= PAGE_ALIGN(last_addr
) - phys_addr
;
595 * Mappings have to fit in the FIX_BTMAP area.
597 nrpages
= size
>> PAGE_SHIFT
;
598 if (nrpages
> NR_FIX_BTMAPS
) {
606 idx0
= FIX_BTMAP_BEGIN
- NR_FIX_BTMAPS
*nesting
;
608 while (nrpages
> 0) {
609 early_set_fixmap(idx
, phys_addr
);
610 phys_addr
+= PAGE_SIZE
;
614 if (early_ioremap_debug
)
615 printk(KERN_CONT
"%08lx + %08lx\n", offset
, fix_to_virt(idx0
));
617 return (void *) (offset
+ fix_to_virt(idx0
));
620 void __init
early_iounmap(void *addr
, unsigned long size
)
622 unsigned long virt_addr
;
623 unsigned long offset
;
624 unsigned int nrpages
;
625 enum fixed_addresses idx
;
628 nesting
= --early_ioremap_nested
;
629 if (WARN_ON(nesting
< 0))
632 if (early_ioremap_debug
) {
633 printk(KERN_INFO
"early_iounmap(%p, %08lx) [%d]\n", addr
,
638 virt_addr
= (unsigned long)addr
;
639 if (virt_addr
< fix_to_virt(FIX_BTMAP_BEGIN
)) {
643 offset
= virt_addr
& ~PAGE_MASK
;
644 nrpages
= PAGE_ALIGN(offset
+ size
- 1) >> PAGE_SHIFT
;
646 idx
= FIX_BTMAP_BEGIN
- NR_FIX_BTMAPS
*nesting
;
647 while (nrpages
> 0) {
648 early_clear_fixmap(idx
);
654 void __this_fixmap_does_not_exist(void)