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>
16 #include <asm/cacheflush.h>
18 #include <asm/fixmap.h>
19 #include <asm/pgtable.h>
20 #include <asm/tlbflush.h>
21 #include <asm/pgalloc.h>
26 unsigned long __phys_addr(unsigned long x
)
28 if (x
>= __START_KERNEL_map
)
29 return x
- __START_KERNEL_map
+ phys_base
;
30 return x
- PAGE_OFFSET
;
32 EXPORT_SYMBOL(__phys_addr
);
34 static inline int phys_addr_valid(unsigned long addr
)
36 return addr
< (1UL << boot_cpu_data
.x86_phys_bits
);
41 static inline int phys_addr_valid(unsigned long addr
)
48 int page_is_ram(unsigned long pagenr
)
50 resource_size_t addr
, end
;
54 * A special case is the first 4Kb of memory;
55 * This is a BIOS owned area, not kernel ram, but generally
56 * not listed as such in the E820 table.
62 * Second special case: Some BIOSen report the PC BIOS
63 * area (640->1Mb) as ram even though it is not.
65 if (pagenr
>= (BIOS_BEGIN
>> PAGE_SHIFT
) &&
66 pagenr
< (BIOS_END
>> PAGE_SHIFT
))
69 for (i
= 0; i
< e820
.nr_map
; i
++) {
73 if (e820
.map
[i
].type
!= E820_RAM
)
75 addr
= (e820
.map
[i
].addr
+ PAGE_SIZE
-1) >> PAGE_SHIFT
;
76 end
= (e820
.map
[i
].addr
+ e820
.map
[i
].size
) >> PAGE_SHIFT
;
79 if ((pagenr
>= addr
) && (pagenr
< end
))
86 * Fix up the linear direct mapping of the kernel to avoid cache attribute
89 int ioremap_change_attr(unsigned long vaddr
, unsigned long size
,
90 unsigned long prot_val
)
92 unsigned long nrpages
= size
>> PAGE_SHIFT
;
98 err
= _set_memory_uc(vaddr
, nrpages
);
101 err
= _set_memory_wc(vaddr
, nrpages
);
104 err
= _set_memory_wb(vaddr
, nrpages
);
112 * Remap an arbitrary physical address space into the kernel virtual
113 * address space. Needed when the kernel wants to access high addresses
116 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
117 * have to convert them into an offset in a page-aligned mapping, but the
118 * caller shouldn't need to know that small detail.
120 static void __iomem
*__ioremap(resource_size_t phys_addr
, unsigned long size
,
121 unsigned long prot_val
)
123 unsigned long pfn
, offset
, vaddr
;
124 resource_size_t last_addr
;
125 struct vm_struct
*area
;
126 unsigned long new_prot_val
;
130 /* Don't allow wraparound or zero size */
131 last_addr
= phys_addr
+ size
- 1;
132 if (!size
|| last_addr
< phys_addr
)
135 if (!phys_addr_valid(phys_addr
)) {
136 printk(KERN_WARNING
"ioremap: invalid physical address %llx\n",
137 (unsigned long long)phys_addr
);
143 * Don't remap the low PCI/ISA area, it's always mapped..
145 if (phys_addr
>= ISA_START_ADDRESS
&& last_addr
< ISA_END_ADDRESS
)
146 return (__force
void __iomem
*)phys_to_virt(phys_addr
);
149 * Don't allow anybody to remap normal RAM that we're using..
151 for (pfn
= phys_addr
>> PAGE_SHIFT
;
152 (pfn
<< PAGE_SHIFT
) < last_addr
; pfn
++) {
154 int is_ram
= page_is_ram(pfn
);
156 if (is_ram
&& pfn_valid(pfn
) && !PageReserved(pfn_to_page(pfn
)))
158 WARN_ON_ONCE(is_ram
);
162 * Mappings have to be page-aligned
164 offset
= phys_addr
& ~PAGE_MASK
;
165 phys_addr
&= PAGE_MASK
;
166 size
= PAGE_ALIGN(last_addr
+1) - phys_addr
;
168 retval
= reserve_memtype(phys_addr
, phys_addr
+ size
,
169 prot_val
, &new_prot_val
);
171 pr_debug("Warning: reserve_memtype returned %d\n", retval
);
175 if (prot_val
!= new_prot_val
) {
177 * Do not fallback to certain memory types with certain
179 * - request is uncached, return cannot be write-back
180 * - request is uncached, return cannot be write-combine
181 * - request is write-combine, return cannot be write-back
183 if ((prot_val
== _PAGE_CACHE_UC
&&
184 (new_prot_val
== _PAGE_CACHE_WB
||
185 new_prot_val
== _PAGE_CACHE_WC
)) ||
186 (prot_val
== _PAGE_CACHE_WC
&&
187 new_prot_val
== _PAGE_CACHE_WB
)) {
189 "ioremap error for 0x%llx-0x%llx, requested 0x%lx, got 0x%lx\n",
190 (unsigned long long)phys_addr
,
191 (unsigned long long)(phys_addr
+ size
),
192 prot_val
, new_prot_val
);
193 free_memtype(phys_addr
, phys_addr
+ size
);
196 prot_val
= new_prot_val
;
202 prot
= PAGE_KERNEL_NOCACHE
;
205 prot
= PAGE_KERNEL_WC
;
215 area
= get_vm_area(size
, VM_IOREMAP
);
218 area
->phys_addr
= phys_addr
;
219 vaddr
= (unsigned long) area
->addr
;
220 if (ioremap_page_range(vaddr
, vaddr
+ size
, phys_addr
, prot
)) {
221 free_memtype(phys_addr
, phys_addr
+ size
);
226 if (ioremap_change_attr(vaddr
, size
, prot_val
) < 0) {
227 free_memtype(phys_addr
, phys_addr
+ size
);
232 return (void __iomem
*) (vaddr
+ offset
);
236 * ioremap_nocache - map bus memory into CPU space
237 * @offset: bus address of the memory
238 * @size: size of the resource to map
240 * ioremap_nocache performs a platform specific sequence of operations to
241 * make bus memory CPU accessible via the readb/readw/readl/writeb/
242 * writew/writel functions and the other mmio helpers. The returned
243 * address is not guaranteed to be usable directly as a virtual
246 * This version of ioremap ensures that the memory is marked uncachable
247 * on the CPU as well as honouring existing caching rules from things like
248 * the PCI bus. Note that there are other caches and buffers on many
249 * busses. In particular driver authors should read up on PCI writes
251 * It's useful if some control registers are in such an area and
252 * write combining or read caching is not desirable:
254 * Must be freed with iounmap.
256 void __iomem
*ioremap_nocache(resource_size_t phys_addr
, unsigned long size
)
258 return __ioremap(phys_addr
, size
, _PAGE_CACHE_UC
);
260 EXPORT_SYMBOL(ioremap_nocache
);
263 * ioremap_wc - map memory into CPU space write combined
264 * @offset: bus address of the memory
265 * @size: size of the resource to map
267 * This version of ioremap ensures that the memory is marked write combining.
268 * Write combining allows faster writes to some hardware devices.
270 * Must be freed with iounmap.
272 void __iomem
*ioremap_wc(unsigned long phys_addr
, unsigned long size
)
275 return __ioremap(phys_addr
, size
, _PAGE_CACHE_WC
);
277 return ioremap_nocache(phys_addr
, size
);
279 EXPORT_SYMBOL(ioremap_wc
);
281 void __iomem
*ioremap_cache(resource_size_t phys_addr
, unsigned long size
)
283 return __ioremap(phys_addr
, size
, _PAGE_CACHE_WB
);
285 EXPORT_SYMBOL(ioremap_cache
);
288 * iounmap - Free a IO remapping
289 * @addr: virtual address from ioremap_*
291 * Caller must ensure there is only one unmapping for the same pointer.
293 void iounmap(volatile void __iomem
*addr
)
295 struct vm_struct
*p
, *o
;
297 if ((void __force
*)addr
<= high_memory
)
301 * __ioremap special-cases the PCI/ISA range by not instantiating a
302 * vm_area and by simply returning an address into the kernel mapping
303 * of ISA space. So handle that here.
305 if (addr
>= phys_to_virt(ISA_START_ADDRESS
) &&
306 addr
< phys_to_virt(ISA_END_ADDRESS
))
309 addr
= (volatile void __iomem
*)
310 (PAGE_MASK
& (unsigned long __force
)addr
);
312 /* Use the vm area unlocked, assuming the caller
313 ensures there isn't another iounmap for the same address
314 in parallel. Reuse of the virtual address is prevented by
315 leaving it in the global lists until we're done with it.
316 cpa takes care of the direct mappings. */
317 read_lock(&vmlist_lock
);
318 for (p
= vmlist
; p
; p
= p
->next
) {
322 read_unlock(&vmlist_lock
);
325 printk(KERN_ERR
"iounmap: bad address %p\n", addr
);
330 free_memtype(p
->phys_addr
, p
->phys_addr
+ get_vm_area_size(p
));
332 /* Finally remove it */
333 o
= remove_vm_area((void *)addr
);
334 BUG_ON(p
!= o
|| o
== NULL
);
337 EXPORT_SYMBOL(iounmap
);
340 * Convert a physical pointer to a virtual kernel pointer for /dev/mem
343 void *xlate_dev_mem_ptr(unsigned long phys
)
346 unsigned long start
= phys
& PAGE_MASK
;
348 /* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
349 if (page_is_ram(start
>> PAGE_SHIFT
))
352 addr
= (void *)ioremap(start
, PAGE_SIZE
);
354 addr
= (void *)((unsigned long)addr
| (phys
& ~PAGE_MASK
));
359 void unxlate_dev_mem_ptr(unsigned long phys
, void *addr
)
361 if (page_is_ram(phys
>> PAGE_SHIFT
))
364 iounmap((void __iomem
*)((unsigned long)addr
& PAGE_MASK
));
370 int __initdata early_ioremap_debug
;
372 static int __init
early_ioremap_debug_setup(char *str
)
374 early_ioremap_debug
= 1;
378 early_param("early_ioremap_debug", early_ioremap_debug_setup
);
380 static __initdata
int after_paging_init
;
381 static pte_t bm_pte
[PAGE_SIZE
/sizeof(pte_t
)]
382 __section(.bss
.page_aligned
);
384 static inline pmd_t
* __init
early_ioremap_pmd(unsigned long addr
)
386 /* Don't assume we're using swapper_pg_dir at this point */
387 pgd_t
*base
= __va(read_cr3());
388 pgd_t
*pgd
= &base
[pgd_index(addr
)];
389 pud_t
*pud
= pud_offset(pgd
, addr
);
390 pmd_t
*pmd
= pmd_offset(pud
, addr
);
395 static inline pte_t
* __init
early_ioremap_pte(unsigned long addr
)
397 return &bm_pte
[pte_index(addr
)];
400 void __init
early_ioremap_init(void)
404 if (early_ioremap_debug
)
405 printk(KERN_INFO
"early_ioremap_init()\n");
407 pmd
= early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN
));
408 memset(bm_pte
, 0, sizeof(bm_pte
));
409 pmd_populate_kernel(&init_mm
, pmd
, bm_pte
);
412 * The boot-ioremap range spans multiple pmds, for which
413 * we are not prepared:
415 if (pmd
!= early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END
))) {
417 printk(KERN_WARNING
"pmd %p != %p\n",
418 pmd
, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END
)));
419 printk(KERN_WARNING
"fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
420 fix_to_virt(FIX_BTMAP_BEGIN
));
421 printk(KERN_WARNING
"fix_to_virt(FIX_BTMAP_END): %08lx\n",
422 fix_to_virt(FIX_BTMAP_END
));
424 printk(KERN_WARNING
"FIX_BTMAP_END: %d\n", FIX_BTMAP_END
);
425 printk(KERN_WARNING
"FIX_BTMAP_BEGIN: %d\n",
430 void __init
early_ioremap_clear(void)
434 if (early_ioremap_debug
)
435 printk(KERN_INFO
"early_ioremap_clear()\n");
437 pmd
= early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN
));
439 paravirt_release_pte(__pa(bm_pte
) >> PAGE_SHIFT
);
443 void __init
early_ioremap_reset(void)
445 enum fixed_addresses idx
;
446 unsigned long addr
, phys
;
449 after_paging_init
= 1;
450 for (idx
= FIX_BTMAP_BEGIN
; idx
>= FIX_BTMAP_END
; idx
--) {
451 addr
= fix_to_virt(idx
);
452 pte
= early_ioremap_pte(addr
);
453 if (pte_present(*pte
)) {
454 phys
= pte_val(*pte
) & PAGE_MASK
;
455 set_fixmap(idx
, phys
);
460 static void __init
__early_set_fixmap(enum fixed_addresses idx
,
461 unsigned long phys
, pgprot_t flags
)
463 unsigned long addr
= __fix_to_virt(idx
);
466 if (idx
>= __end_of_fixed_addresses
) {
470 pte
= early_ioremap_pte(addr
);
471 if (pgprot_val(flags
))
472 set_pte(pte
, pfn_pte(phys
>> PAGE_SHIFT
, flags
));
474 pte_clear(NULL
, addr
, pte
);
475 __flush_tlb_one(addr
);
478 static inline void __init
early_set_fixmap(enum fixed_addresses idx
,
481 if (after_paging_init
)
482 set_fixmap(idx
, phys
);
484 __early_set_fixmap(idx
, phys
, PAGE_KERNEL
);
487 static inline void __init
early_clear_fixmap(enum fixed_addresses idx
)
489 if (after_paging_init
)
492 __early_set_fixmap(idx
, 0, __pgprot(0));
496 int __initdata early_ioremap_nested
;
498 static int __init
check_early_ioremap_leak(void)
500 if (!early_ioremap_nested
)
504 "Debug warning: early ioremap leak of %d areas detected.\n",
505 early_ioremap_nested
);
507 "please boot with early_ioremap_debug and report the dmesg.\n");
512 late_initcall(check_early_ioremap_leak
);
514 void __init
*early_ioremap(unsigned long phys_addr
, unsigned long size
)
516 unsigned long offset
, last_addr
;
517 unsigned int nrpages
, nesting
;
518 enum fixed_addresses idx0
, idx
;
520 WARN_ON(system_state
!= SYSTEM_BOOTING
);
522 nesting
= early_ioremap_nested
;
523 if (early_ioremap_debug
) {
524 printk(KERN_INFO
"early_ioremap(%08lx, %08lx) [%d] => ",
525 phys_addr
, size
, nesting
);
529 /* Don't allow wraparound or zero size */
530 last_addr
= phys_addr
+ size
- 1;
531 if (!size
|| last_addr
< phys_addr
) {
536 if (nesting
>= FIX_BTMAPS_NESTING
) {
540 early_ioremap_nested
++;
542 * Mappings have to be page-aligned
544 offset
= phys_addr
& ~PAGE_MASK
;
545 phys_addr
&= PAGE_MASK
;
546 size
= PAGE_ALIGN(last_addr
) - phys_addr
;
549 * Mappings have to fit in the FIX_BTMAP area.
551 nrpages
= size
>> PAGE_SHIFT
;
552 if (nrpages
> NR_FIX_BTMAPS
) {
560 idx0
= FIX_BTMAP_BEGIN
- NR_FIX_BTMAPS
*nesting
;
562 while (nrpages
> 0) {
563 early_set_fixmap(idx
, phys_addr
);
564 phys_addr
+= PAGE_SIZE
;
568 if (early_ioremap_debug
)
569 printk(KERN_CONT
"%08lx + %08lx\n", offset
, fix_to_virt(idx0
));
571 return (void *) (offset
+ fix_to_virt(idx0
));
574 void __init
early_iounmap(void *addr
, unsigned long size
)
576 unsigned long virt_addr
;
577 unsigned long offset
;
578 unsigned int nrpages
;
579 enum fixed_addresses idx
;
580 unsigned int nesting
;
582 nesting
= --early_ioremap_nested
;
583 WARN_ON(nesting
< 0);
585 if (early_ioremap_debug
) {
586 printk(KERN_INFO
"early_iounmap(%p, %08lx) [%d]\n", addr
,
591 virt_addr
= (unsigned long)addr
;
592 if (virt_addr
< fix_to_virt(FIX_BTMAP_BEGIN
)) {
596 offset
= virt_addr
& ~PAGE_MASK
;
597 nrpages
= PAGE_ALIGN(offset
+ size
- 1) >> PAGE_SHIFT
;
599 idx
= FIX_BTMAP_BEGIN
- NR_FIX_BTMAPS
*nesting
;
600 while (nrpages
> 0) {
601 early_clear_fixmap(idx
);
607 void __this_fixmap_does_not_exist(void)
612 #endif /* CONFIG_X86_32 */