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>
28 * Fix up the linear direct mapping of the kernel to avoid cache attribute
31 int ioremap_change_attr(unsigned long vaddr
, unsigned long size
,
32 enum page_cache_mode pcm
)
34 unsigned long nrpages
= size
>> PAGE_SHIFT
;
38 case _PAGE_CACHE_MODE_UC
:
40 err
= _set_memory_uc(vaddr
, nrpages
);
42 case _PAGE_CACHE_MODE_WC
:
43 err
= _set_memory_wc(vaddr
, nrpages
);
45 case _PAGE_CACHE_MODE_WB
:
46 err
= _set_memory_wb(vaddr
, nrpages
);
53 static int __ioremap_check_ram(unsigned long start_pfn
, unsigned long nr_pages
,
58 for (i
= 0; i
< nr_pages
; ++i
)
59 if (pfn_valid(start_pfn
+ i
) &&
60 !PageReserved(pfn_to_page(start_pfn
+ i
)))
63 WARN_ONCE(1, "ioremap on RAM pfn 0x%lx\n", start_pfn
);
69 * Remap an arbitrary physical address space into the kernel virtual
70 * address space. Needed when the kernel wants to access high addresses
73 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
74 * have to convert them into an offset in a page-aligned mapping, but the
75 * caller shouldn't need to know that small detail.
77 static void __iomem
*__ioremap_caller(resource_size_t phys_addr
,
78 unsigned long size
, enum page_cache_mode pcm
, void *caller
)
80 unsigned long offset
, vaddr
;
81 resource_size_t pfn
, last_pfn
, last_addr
;
82 const resource_size_t unaligned_phys_addr
= phys_addr
;
83 const unsigned long unaligned_size
= size
;
84 struct vm_struct
*area
;
85 enum page_cache_mode new_pcm
;
88 void __iomem
*ret_addr
;
91 /* Don't allow wraparound or zero size */
92 last_addr
= phys_addr
+ size
- 1;
93 if (!size
|| last_addr
< phys_addr
)
96 if (!phys_addr_valid(phys_addr
)) {
97 printk(KERN_WARNING
"ioremap: invalid physical address %llx\n",
98 (unsigned long long)phys_addr
);
104 * Don't remap the low PCI/ISA area, it's always mapped..
106 if (is_ISA_range(phys_addr
, last_addr
))
107 return (__force
void __iomem
*)phys_to_virt(phys_addr
);
110 * Don't allow anybody to remap normal RAM that we're using..
112 /* First check if whole region can be identified as RAM or not */
113 ram_region
= region_is_ram(phys_addr
, size
);
114 if (ram_region
> 0) {
115 WARN_ONCE(1, "ioremap on RAM at 0x%lx - 0x%lx\n",
116 (unsigned long int)phys_addr
,
117 (unsigned long int)last_addr
);
121 /* If could not be identified(-1), check page by page */
122 if (ram_region
< 0) {
123 pfn
= phys_addr
>> PAGE_SHIFT
;
124 last_pfn
= last_addr
>> PAGE_SHIFT
;
125 if (walk_system_ram_range(pfn
, last_pfn
- pfn
+ 1, NULL
,
126 __ioremap_check_ram
) == 1)
130 * Mappings have to be page-aligned
132 offset
= phys_addr
& ~PAGE_MASK
;
133 phys_addr
&= PHYSICAL_PAGE_MASK
;
134 size
= PAGE_ALIGN(last_addr
+1) - phys_addr
;
136 retval
= reserve_memtype(phys_addr
, (u64
)phys_addr
+ size
,
139 printk(KERN_ERR
"ioremap reserve_memtype failed %d\n", retval
);
143 if (pcm
!= new_pcm
) {
144 if (!is_new_memtype_allowed(phys_addr
, size
, pcm
, new_pcm
)) {
146 "ioremap error for 0x%llx-0x%llx, requested 0x%x, got 0x%x\n",
147 (unsigned long long)phys_addr
,
148 (unsigned long long)(phys_addr
+ size
),
150 goto err_free_memtype
;
155 prot
= PAGE_KERNEL_IO
;
157 case _PAGE_CACHE_MODE_UC
:
159 prot
= __pgprot(pgprot_val(prot
) |
160 cachemode2protval(_PAGE_CACHE_MODE_UC
));
162 case _PAGE_CACHE_MODE_UC_MINUS
:
163 prot
= __pgprot(pgprot_val(prot
) |
164 cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS
));
166 case _PAGE_CACHE_MODE_WC
:
167 prot
= __pgprot(pgprot_val(prot
) |
168 cachemode2protval(_PAGE_CACHE_MODE_WC
));
170 case _PAGE_CACHE_MODE_WB
:
177 area
= get_vm_area_caller(size
, VM_IOREMAP
, caller
);
179 goto err_free_memtype
;
180 area
->phys_addr
= phys_addr
;
181 vaddr
= (unsigned long) area
->addr
;
183 if (kernel_map_sync_memtype(phys_addr
, size
, pcm
))
186 if (ioremap_page_range(vaddr
, vaddr
+ size
, phys_addr
, prot
))
189 ret_addr
= (void __iomem
*) (vaddr
+ offset
);
190 mmiotrace_ioremap(unaligned_phys_addr
, unaligned_size
, ret_addr
);
193 * Check if the request spans more than any BAR in the iomem resource
196 WARN_ONCE(iomem_map_sanity_check(unaligned_phys_addr
, unaligned_size
),
197 KERN_INFO
"Info: mapping multiple BARs. Your kernel is fine.");
203 free_memtype(phys_addr
, phys_addr
+ size
);
208 * ioremap_nocache - map bus memory into CPU space
209 * @phys_addr: bus address of the memory
210 * @size: size of the resource to map
212 * ioremap_nocache performs a platform specific sequence of operations to
213 * make bus memory CPU accessible via the readb/readw/readl/writeb/
214 * writew/writel functions and the other mmio helpers. The returned
215 * address is not guaranteed to be usable directly as a virtual
218 * This version of ioremap ensures that the memory is marked uncachable
219 * on the CPU as well as honouring existing caching rules from things like
220 * the PCI bus. Note that there are other caches and buffers on many
221 * busses. In particular driver authors should read up on PCI writes
223 * It's useful if some control registers are in such an area and
224 * write combining or read caching is not desirable:
226 * Must be freed with iounmap.
228 void __iomem
*ioremap_nocache(resource_size_t phys_addr
, unsigned long size
)
231 * Ideally, this should be:
232 * pat_enabled ? _PAGE_CACHE_MODE_UC : _PAGE_CACHE_MODE_UC_MINUS;
234 * Till we fix all X drivers to use ioremap_wc(), we will use
237 enum page_cache_mode pcm
= _PAGE_CACHE_MODE_UC_MINUS
;
239 return __ioremap_caller(phys_addr
, size
, pcm
,
240 __builtin_return_address(0));
242 EXPORT_SYMBOL(ioremap_nocache
);
245 * ioremap_wc - map memory into CPU space write combined
246 * @phys_addr: bus address of the memory
247 * @size: size of the resource to map
249 * This version of ioremap ensures that the memory is marked write combining.
250 * Write combining allows faster writes to some hardware devices.
252 * Must be freed with iounmap.
254 void __iomem
*ioremap_wc(resource_size_t phys_addr
, unsigned long size
)
257 return __ioremap_caller(phys_addr
, size
, _PAGE_CACHE_MODE_WC
,
258 __builtin_return_address(0));
260 return ioremap_nocache(phys_addr
, size
);
262 EXPORT_SYMBOL(ioremap_wc
);
264 void __iomem
*ioremap_cache(resource_size_t phys_addr
, unsigned long size
)
266 return __ioremap_caller(phys_addr
, size
, _PAGE_CACHE_MODE_WB
,
267 __builtin_return_address(0));
269 EXPORT_SYMBOL(ioremap_cache
);
271 void __iomem
*ioremap_prot(resource_size_t phys_addr
, unsigned long size
,
272 unsigned long prot_val
)
274 return __ioremap_caller(phys_addr
, size
,
275 pgprot2cachemode(__pgprot(prot_val
)),
276 __builtin_return_address(0));
278 EXPORT_SYMBOL(ioremap_prot
);
281 * iounmap - Free a IO remapping
282 * @addr: virtual address from ioremap_*
284 * Caller must ensure there is only one unmapping for the same pointer.
286 void iounmap(volatile void __iomem
*addr
)
288 struct vm_struct
*p
, *o
;
290 if ((void __force
*)addr
<= high_memory
)
294 * __ioremap special-cases the PCI/ISA range by not instantiating a
295 * vm_area and by simply returning an address into the kernel mapping
296 * of ISA space. So handle that here.
298 if ((void __force
*)addr
>= phys_to_virt(ISA_START_ADDRESS
) &&
299 (void __force
*)addr
< phys_to_virt(ISA_END_ADDRESS
))
302 addr
= (volatile void __iomem
*)
303 (PAGE_MASK
& (unsigned long __force
)addr
);
305 mmiotrace_iounmap(addr
);
307 /* Use the vm area unlocked, assuming the caller
308 ensures there isn't another iounmap for the same address
309 in parallel. Reuse of the virtual address is prevented by
310 leaving it in the global lists until we're done with it.
311 cpa takes care of the direct mappings. */
312 p
= find_vm_area((void __force
*)addr
);
315 printk(KERN_ERR
"iounmap: bad address %p\n", addr
);
320 free_memtype(p
->phys_addr
, p
->phys_addr
+ get_vm_area_size(p
));
322 /* Finally remove it */
323 o
= remove_vm_area((void __force
*)addr
);
324 BUG_ON(p
!= o
|| o
== NULL
);
327 EXPORT_SYMBOL(iounmap
);
330 * Convert a physical pointer to a virtual kernel pointer for /dev/mem
333 void *xlate_dev_mem_ptr(phys_addr_t phys
)
336 unsigned long start
= phys
& PAGE_MASK
;
338 /* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
339 if (page_is_ram(start
>> PAGE_SHIFT
))
342 addr
= (void __force
*)ioremap_cache(start
, PAGE_SIZE
);
344 addr
= (void *)((unsigned long)addr
| (phys
& ~PAGE_MASK
));
349 void unxlate_dev_mem_ptr(phys_addr_t phys
, void *addr
)
351 if (page_is_ram(phys
>> PAGE_SHIFT
))
354 iounmap((void __iomem
*)((unsigned long)addr
& PAGE_MASK
));
358 static pte_t bm_pte
[PAGE_SIZE
/sizeof(pte_t
)] __page_aligned_bss
;
360 static inline pmd_t
* __init
early_ioremap_pmd(unsigned long addr
)
362 /* Don't assume we're using swapper_pg_dir at this point */
363 pgd_t
*base
= __va(read_cr3());
364 pgd_t
*pgd
= &base
[pgd_index(addr
)];
365 pud_t
*pud
= pud_offset(pgd
, addr
);
366 pmd_t
*pmd
= pmd_offset(pud
, addr
);
371 static inline pte_t
* __init
early_ioremap_pte(unsigned long addr
)
373 return &bm_pte
[pte_index(addr
)];
376 bool __init
is_early_ioremap_ptep(pte_t
*ptep
)
378 return ptep
>= &bm_pte
[0] && ptep
< &bm_pte
[PAGE_SIZE
/sizeof(pte_t
)];
381 void __init
early_ioremap_init(void)
386 BUILD_BUG_ON((fix_to_virt(0) + PAGE_SIZE
) & ((1 << PMD_SHIFT
) - 1));
388 WARN_ON((fix_to_virt(0) + PAGE_SIZE
) & ((1 << PMD_SHIFT
) - 1));
391 early_ioremap_setup();
393 pmd
= early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN
));
394 memset(bm_pte
, 0, sizeof(bm_pte
));
395 pmd_populate_kernel(&init_mm
, pmd
, bm_pte
);
398 * The boot-ioremap range spans multiple pmds, for which
399 * we are not prepared:
401 #define __FIXADDR_TOP (-PAGE_SIZE)
402 BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN
) >> PMD_SHIFT
)
403 != (__fix_to_virt(FIX_BTMAP_END
) >> PMD_SHIFT
));
405 if (pmd
!= early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END
))) {
407 printk(KERN_WARNING
"pmd %p != %p\n",
408 pmd
, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END
)));
409 printk(KERN_WARNING
"fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
410 fix_to_virt(FIX_BTMAP_BEGIN
));
411 printk(KERN_WARNING
"fix_to_virt(FIX_BTMAP_END): %08lx\n",
412 fix_to_virt(FIX_BTMAP_END
));
414 printk(KERN_WARNING
"FIX_BTMAP_END: %d\n", FIX_BTMAP_END
);
415 printk(KERN_WARNING
"FIX_BTMAP_BEGIN: %d\n",
420 void __init
__early_set_fixmap(enum fixed_addresses idx
,
421 phys_addr_t phys
, pgprot_t flags
)
423 unsigned long addr
= __fix_to_virt(idx
);
426 if (idx
>= __end_of_fixed_addresses
) {
430 pte
= early_ioremap_pte(addr
);
432 if (pgprot_val(flags
))
433 set_pte(pte
, pfn_pte(phys
>> PAGE_SHIFT
, flags
));
435 pte_clear(&init_mm
, addr
, pte
);
436 __flush_tlb_one(addr
);