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 * Check if the request spans more than any BAR in the iomem resource
156 WARN_ON(iomem_map_sanity_check(phys_addr, size));
159 * Don't allow anybody to remap normal RAM that we're using..
161 for (pfn = phys_addr >> PAGE_SHIFT;
162 (pfn << PAGE_SHIFT) < (last_addr & PAGE_MASK);
165 int is_ram = page_is_ram(pfn);
167 if (is_ram && pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn)))
169 WARN_ON_ONCE(is_ram);
173 * Mappings have to be page-aligned
175 offset = phys_addr & ~PAGE_MASK;
176 phys_addr &= PAGE_MASK;
177 size = PAGE_ALIGN(last_addr+1) - phys_addr;
179 retval = reserve_memtype(phys_addr, (u64)phys_addr + size,
180 prot_val, &new_prot_val);
182 pr_debug("Warning: reserve_memtype returned %d\n", retval);
186 if (prot_val != new_prot_val) {
188 * Do not fallback to certain memory types with certain
190 * - request is uc-, return cannot be write-back
191 * - request is uc-, return cannot be write-combine
192 * - request is write-combine, return cannot be write-back
194 if ((prot_val == _PAGE_CACHE_UC_MINUS &&
195 (new_prot_val == _PAGE_CACHE_WB ||
196 new_prot_val == _PAGE_CACHE_WC)) ||
197 (prot_val == _PAGE_CACHE_WC &&
198 new_prot_val == _PAGE_CACHE_WB)) {
200 "ioremap error for 0x%llx-0x%llx, requested 0x%lx, got 0x%lx\n",
201 (unsigned long long)phys_addr,
202 (unsigned long long)(phys_addr + size),
203 prot_val, new_prot_val);
204 free_memtype(phys_addr, phys_addr + size);
207 prot_val = new_prot_val;
213 prot = PAGE_KERNEL_NOCACHE;
215 case _PAGE_CACHE_UC_MINUS:
216 prot = PAGE_KERNEL_UC_MINUS;
219 prot = PAGE_KERNEL_WC;
229 area = get_vm_area_caller(size, VM_IOREMAP, caller);
232 area->phys_addr = phys_addr;
233 vaddr = (unsigned long) area->addr;
234 if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
235 free_memtype(phys_addr, phys_addr + size);
240 if (ioremap_change_attr(vaddr, size, prot_val) < 0) {
241 free_memtype(phys_addr, phys_addr + size);
246 ret_addr = (void __iomem *) (vaddr + offset);
247 mmiotrace_ioremap(unaligned_phys_addr, unaligned_size, ret_addr);
253 * ioremap_nocache - map bus memory into CPU space
254 * @offset: bus address of the memory
255 * @size: size of the resource to map
257 * ioremap_nocache performs a platform specific sequence of operations to
258 * make bus memory CPU accessible via the readb/readw/readl/writeb/
259 * writew/writel functions and the other mmio helpers. The returned
260 * address is not guaranteed to be usable directly as a virtual
263 * This version of ioremap ensures that the memory is marked uncachable
264 * on the CPU as well as honouring existing caching rules from things like
265 * the PCI bus. Note that there are other caches and buffers on many
266 * busses. In particular driver authors should read up on PCI writes
268 * It's useful if some control registers are in such an area and
269 * write combining or read caching is not desirable:
271 * Must be freed with iounmap.
273 void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size)
276 * Ideally, this should be:
277 * pat_enabled ? _PAGE_CACHE_UC : _PAGE_CACHE_UC_MINUS;
279 * Till we fix all X drivers to use ioremap_wc(), we will use
282 unsigned long val = _PAGE_CACHE_UC_MINUS;
284 return __ioremap_caller(phys_addr, size, val,
285 __builtin_return_address(0));
287 EXPORT_SYMBOL(ioremap_nocache);
290 * ioremap_wc - map memory into CPU space write combined
291 * @offset: bus address of the memory
292 * @size: size of the resource to map
294 * This version of ioremap ensures that the memory is marked write combining.
295 * Write combining allows faster writes to some hardware devices.
297 * Must be freed with iounmap.
299 void __iomem *ioremap_wc(unsigned long phys_addr, unsigned long size)
302 return __ioremap_caller(phys_addr, size, _PAGE_CACHE_WC,
303 __builtin_return_address(0));
305 return ioremap_nocache(phys_addr, size);
307 EXPORT_SYMBOL(ioremap_wc);
309 void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
311 return __ioremap_caller(phys_addr, size, _PAGE_CACHE_WB,
312 __builtin_return_address(0));
314 EXPORT_SYMBOL(ioremap_cache);
316 static void __iomem *ioremap_default(resource_size_t phys_addr,
324 * - WB for WB-able memory and no other conflicting mappings
325 * - UC_MINUS for non-WB-able memory with no other conflicting mappings
326 * - Inherit from confliting mappings otherwise
328 err = reserve_memtype(phys_addr, phys_addr + size, -1, &flags);
332 ret = (void *) __ioremap_caller(phys_addr, size, flags,
333 __builtin_return_address(0));
335 free_memtype(phys_addr, phys_addr + size);
336 return (void __iomem *)ret;
339 void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
340 unsigned long prot_val)
342 return __ioremap_caller(phys_addr, size, (prot_val & _PAGE_CACHE_MASK),
343 __builtin_return_address(0));
345 EXPORT_SYMBOL(ioremap_prot);
348 * iounmap - Free a IO remapping
349 * @addr: virtual address from ioremap_*
351 * Caller must ensure there is only one unmapping for the same pointer.
353 void iounmap(volatile void __iomem *addr)
355 struct vm_struct *p, *o;
357 if ((void __force *)addr <= high_memory)
361 * __ioremap special-cases the PCI/ISA range by not instantiating a
362 * vm_area and by simply returning an address into the kernel mapping
363 * of ISA space. So handle that here.
365 if ((void __force *)addr >= phys_to_virt(ISA_START_ADDRESS) &&
366 (void __force *)addr < phys_to_virt(ISA_END_ADDRESS))
369 addr = (volatile void __iomem *)
370 (PAGE_MASK & (unsigned long __force)addr);
372 mmiotrace_iounmap(addr);
374 /* Use the vm area unlocked, assuming the caller
375 ensures there isn't another iounmap for the same address
376 in parallel. Reuse of the virtual address is prevented by
377 leaving it in the global lists until we're done with it.
378 cpa takes care of the direct mappings. */
379 read_lock(&vmlist_lock);
380 for (p = vmlist; p; p = p->next) {
381 if (p->addr == (void __force *)addr)
384 read_unlock(&vmlist_lock);
387 printk(KERN_ERR "iounmap: bad address %p\n", addr);
392 free_memtype(p->phys_addr, p->phys_addr + get_vm_area_size(p));
394 /* Finally remove it */
395 o = remove_vm_area((void __force *)addr);
396 BUG_ON(p != o || o == NULL);
399 EXPORT_SYMBOL(iounmap);
402 * Convert a physical pointer to a virtual kernel pointer for /dev/mem
405 void *xlate_dev_mem_ptr(unsigned long phys)
408 unsigned long start = phys & PAGE_MASK;
410 /* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
411 if (page_is_ram(start >> PAGE_SHIFT))
414 addr = (void __force *)ioremap_default(start, PAGE_SIZE);
416 addr = (void *)((unsigned long)addr | (phys & ~PAGE_MASK));
421 void unxlate_dev_mem_ptr(unsigned long phys, void *addr)
423 if (page_is_ram(phys >> PAGE_SHIFT))
426 iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK));
430 int __initdata early_ioremap_debug;
432 static int __init early_ioremap_debug_setup(char *str)
434 early_ioremap_debug = 1;
438 early_param("early_ioremap_debug", early_ioremap_debug_setup);
440 static __initdata int after_paging_init;
441 static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss;
443 static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
445 /* Don't assume we're using swapper_pg_dir at this point */
446 pgd_t *base = __va(read_cr3());
447 pgd_t *pgd = &base[pgd_index(addr)];
448 pud_t *pud = pud_offset(pgd, addr);
449 pmd_t *pmd = pmd_offset(pud, addr);
454 static inline pte_t * __init early_ioremap_pte(unsigned long addr)
456 return &bm_pte[pte_index(addr)];
459 void __init early_ioremap_init(void)
463 if (early_ioremap_debug)
464 printk(KERN_INFO "early_ioremap_init()\n");
466 pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
467 memset(bm_pte, 0, sizeof(bm_pte));
468 pmd_populate_kernel(&init_mm, pmd, bm_pte);
471 * The boot-ioremap range spans multiple pmds, for which
472 * we are not prepared:
474 if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
476 printk(KERN_WARNING "pmd %p != %p\n",
477 pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END)));
478 printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
479 fix_to_virt(FIX_BTMAP_BEGIN));
480 printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END): %08lx\n",
481 fix_to_virt(FIX_BTMAP_END));
483 printk(KERN_WARNING "FIX_BTMAP_END: %d\n", FIX_BTMAP_END);
484 printk(KERN_WARNING "FIX_BTMAP_BEGIN: %d\n",
489 void __init early_ioremap_clear(void)
493 if (early_ioremap_debug)
494 printk(KERN_INFO "early_ioremap_clear()\n");
496 pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
498 paravirt_release_pte(__pa(bm_pte) >> PAGE_SHIFT);
502 void __init early_ioremap_reset(void)
504 enum fixed_addresses idx;
505 unsigned long addr, phys;
508 after_paging_init = 1;
509 for (idx = FIX_BTMAP_BEGIN; idx >= FIX_BTMAP_END; idx--) {
510 addr = fix_to_virt(idx);
511 pte = early_ioremap_pte(addr);
512 if (pte_present(*pte)) {
513 phys = pte_val(*pte) & PAGE_MASK;
514 set_fixmap(idx, phys);
519 static void __init __early_set_fixmap(enum fixed_addresses idx,
520 unsigned long phys, pgprot_t flags)
522 unsigned long addr = __fix_to_virt(idx);
525 if (idx >= __end_of_fixed_addresses) {
529 pte = early_ioremap_pte(addr);
531 if (pgprot_val(flags))
532 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
534 pte_clear(&init_mm, addr, pte);
535 __flush_tlb_one(addr);
538 static inline void __init early_set_fixmap(enum fixed_addresses idx,
541 if (after_paging_init)
542 set_fixmap(idx, phys);
544 __early_set_fixmap(idx, phys, PAGE_KERNEL);
547 static inline void __init early_clear_fixmap(enum fixed_addresses idx)
549 if (after_paging_init)
552 __early_set_fixmap(idx, 0, __pgprot(0));
556 int __initdata early_ioremap_nested;
558 static int __init check_early_ioremap_leak(void)
560 if (!early_ioremap_nested)
563 "Debug warning: early ioremap leak of %d areas detected.\n",
564 early_ioremap_nested);
566 "please boot with early_ioremap_debug and report the dmesg.\n");
570 late_initcall(check_early_ioremap_leak);
572 void __init *early_ioremap(unsigned long phys_addr, unsigned long size)
574 unsigned long offset, last_addr;
575 unsigned int nrpages, nesting;
576 enum fixed_addresses idx0, idx;
578 WARN_ON(system_state != SYSTEM_BOOTING);
580 nesting = early_ioremap_nested;
581 if (early_ioremap_debug) {
582 printk(KERN_INFO "early_ioremap(%08lx, %08lx) [%d] => ",
583 phys_addr, size, nesting);
587 /* Don't allow wraparound or zero size */
588 last_addr = phys_addr + size - 1;
589 if (!size || last_addr < phys_addr) {
594 if (nesting >= FIX_BTMAPS_NESTING) {
598 early_ioremap_nested++;
600 * Mappings have to be page-aligned
602 offset = phys_addr & ~PAGE_MASK;
603 phys_addr &= PAGE_MASK;
604 size = PAGE_ALIGN(last_addr) - phys_addr;
607 * Mappings have to fit in the FIX_BTMAP area.
609 nrpages = size >> PAGE_SHIFT;
610 if (nrpages > NR_FIX_BTMAPS) {
618 idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
620 while (nrpages > 0) {
621 early_set_fixmap(idx, phys_addr);
622 phys_addr += PAGE_SIZE;
626 if (early_ioremap_debug)
627 printk(KERN_CONT "%08lx + %08lx\n", offset, fix_to_virt(idx0));
629 return (void *) (offset + fix_to_virt(idx0));
632 void __init early_iounmap(void *addr, unsigned long size)
634 unsigned long virt_addr;
635 unsigned long offset;
636 unsigned int nrpages;
637 enum fixed_addresses idx;
640 nesting = --early_ioremap_nested;
641 if (WARN_ON(nesting < 0))
644 if (early_ioremap_debug) {
645 printk(KERN_INFO "early_iounmap(%p, %08lx) [%d]\n", addr,
650 virt_addr = (unsigned long)addr;
651 if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)) {
655 offset = virt_addr & ~PAGE_MASK;
656 nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT;
658 idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
659 while (nrpages > 0) {
660 early_clear_fixmap(idx);
666 void __this_fixmap_does_not_exist(void)