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 unsigned long prot_val)
34 unsigned long nrpages = size >> PAGE_SHIFT;
40 err = _set_memory_uc(vaddr, nrpages);
43 err = _set_memory_wc(vaddr, nrpages);
46 err = _set_memory_wb(vaddr, nrpages);
54 * Remap an arbitrary physical address space into the kernel virtual
55 * address space. Needed when the kernel wants to access high addresses
58 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
59 * have to convert them into an offset in a page-aligned mapping, but the
60 * caller shouldn't need to know that small detail.
62 static void __iomem *__ioremap_caller(resource_size_t phys_addr,
63 unsigned long size, unsigned long prot_val, void *caller)
65 unsigned long pfn, offset, vaddr;
66 resource_size_t last_addr;
67 const resource_size_t unaligned_phys_addr = phys_addr;
68 const unsigned long unaligned_size = size;
69 struct vm_struct *area;
70 unsigned long new_prot_val;
73 void __iomem *ret_addr;
75 /* Don't allow wraparound or zero size */
76 last_addr = phys_addr + size - 1;
77 if (!size || last_addr < phys_addr)
80 if (!phys_addr_valid(phys_addr)) {
81 printk(KERN_WARNING "ioremap: invalid physical address %llx\n",
82 (unsigned long long)phys_addr);
88 * Don't remap the low PCI/ISA area, it's always mapped..
90 if (is_ISA_range(phys_addr, last_addr))
91 return (__force void __iomem *)phys_to_virt(phys_addr);
94 * Check if the request spans more than any BAR in the iomem resource
97 WARN_ONCE(iomem_map_sanity_check(phys_addr, size),
98 KERN_INFO "Info: mapping multiple BARs. Your kernel is fine.");
101 * Don't allow anybody to remap normal RAM that we're using..
103 for (pfn = phys_addr >> PAGE_SHIFT;
104 (pfn << PAGE_SHIFT) < (last_addr & PAGE_MASK);
107 int is_ram = page_is_ram(pfn);
109 if (is_ram && pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn)))
111 WARN_ON_ONCE(is_ram);
115 * Mappings have to be page-aligned
117 offset = phys_addr & ~PAGE_MASK;
118 phys_addr &= PAGE_MASK;
119 size = PAGE_ALIGN(last_addr+1) - phys_addr;
121 retval = reserve_memtype(phys_addr, (u64)phys_addr + size,
122 prot_val, &new_prot_val);
124 printk(KERN_ERR "ioremap reserve_memtype failed %d\n", retval);
128 if (prot_val != new_prot_val) {
129 if (!is_new_memtype_allowed(phys_addr, size,
130 prot_val, new_prot_val)) {
132 "ioremap error for 0x%llx-0x%llx, requested 0x%lx, got 0x%lx\n",
133 (unsigned long long)phys_addr,
134 (unsigned long long)(phys_addr + size),
135 prot_val, new_prot_val);
136 goto err_free_memtype;
138 prot_val = new_prot_val;
144 prot = PAGE_KERNEL_IO_NOCACHE;
146 case _PAGE_CACHE_UC_MINUS:
147 prot = PAGE_KERNEL_IO_UC_MINUS;
150 prot = PAGE_KERNEL_IO_WC;
153 prot = PAGE_KERNEL_IO;
160 area = get_vm_area_caller(size, VM_IOREMAP, caller);
162 goto err_free_memtype;
163 area->phys_addr = phys_addr;
164 vaddr = (unsigned long) area->addr;
166 if (kernel_map_sync_memtype(phys_addr, size, prot_val))
169 if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot))
172 ret_addr = (void __iomem *) (vaddr + offset);
173 mmiotrace_ioremap(unaligned_phys_addr, unaligned_size, ret_addr);
179 free_memtype(phys_addr, phys_addr + size);
184 * ioremap_nocache - map bus memory into CPU space
185 * @offset: bus address of the memory
186 * @size: size of the resource to map
188 * ioremap_nocache performs a platform specific sequence of operations to
189 * make bus memory CPU accessible via the readb/readw/readl/writeb/
190 * writew/writel functions and the other mmio helpers. The returned
191 * address is not guaranteed to be usable directly as a virtual
194 * This version of ioremap ensures that the memory is marked uncachable
195 * on the CPU as well as honouring existing caching rules from things like
196 * the PCI bus. Note that there are other caches and buffers on many
197 * busses. In particular driver authors should read up on PCI writes
199 * It's useful if some control registers are in such an area and
200 * write combining or read caching is not desirable:
202 * Must be freed with iounmap.
204 void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size)
207 * Ideally, this should be:
208 * pat_enabled ? _PAGE_CACHE_UC : _PAGE_CACHE_UC_MINUS;
210 * Till we fix all X drivers to use ioremap_wc(), we will use
213 unsigned long val = _PAGE_CACHE_UC_MINUS;
215 return __ioremap_caller(phys_addr, size, val,
216 __builtin_return_address(0));
218 EXPORT_SYMBOL(ioremap_nocache);
221 * ioremap_wc - map memory into CPU space write combined
222 * @offset: bus address of the memory
223 * @size: size of the resource to map
225 * This version of ioremap ensures that the memory is marked write combining.
226 * Write combining allows faster writes to some hardware devices.
228 * Must be freed with iounmap.
230 void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size)
233 return __ioremap_caller(phys_addr, size, _PAGE_CACHE_WC,
234 __builtin_return_address(0));
236 return ioremap_nocache(phys_addr, size);
238 EXPORT_SYMBOL(ioremap_wc);
240 void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
242 return __ioremap_caller(phys_addr, size, _PAGE_CACHE_WB,
243 __builtin_return_address(0));
245 EXPORT_SYMBOL(ioremap_cache);
247 void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
248 unsigned long prot_val)
250 return __ioremap_caller(phys_addr, size, (prot_val & _PAGE_CACHE_MASK),
251 __builtin_return_address(0));
253 EXPORT_SYMBOL(ioremap_prot);
256 * iounmap - Free a IO remapping
257 * @addr: virtual address from ioremap_*
259 * Caller must ensure there is only one unmapping for the same pointer.
261 void iounmap(volatile void __iomem *addr)
263 struct vm_struct *p, *o;
265 if ((void __force *)addr <= high_memory)
269 * __ioremap special-cases the PCI/ISA range by not instantiating a
270 * vm_area and by simply returning an address into the kernel mapping
271 * of ISA space. So handle that here.
273 if ((void __force *)addr >= phys_to_virt(ISA_START_ADDRESS) &&
274 (void __force *)addr < phys_to_virt(ISA_END_ADDRESS))
277 addr = (volatile void __iomem *)
278 (PAGE_MASK & (unsigned long __force)addr);
280 mmiotrace_iounmap(addr);
282 /* Use the vm area unlocked, assuming the caller
283 ensures there isn't another iounmap for the same address
284 in parallel. Reuse of the virtual address is prevented by
285 leaving it in the global lists until we're done with it.
286 cpa takes care of the direct mappings. */
287 read_lock(&vmlist_lock);
288 for (p = vmlist; p; p = p->next) {
289 if (p->addr == (void __force *)addr)
292 read_unlock(&vmlist_lock);
295 printk(KERN_ERR "iounmap: bad address %p\n", addr);
300 free_memtype(p->phys_addr, p->phys_addr + get_vm_area_size(p));
302 /* Finally remove it */
303 o = remove_vm_area((void __force *)addr);
304 BUG_ON(p != o || o == NULL);
307 EXPORT_SYMBOL(iounmap);
310 * Convert a physical pointer to a virtual kernel pointer for /dev/mem
313 void *xlate_dev_mem_ptr(unsigned long phys)
316 unsigned long start = phys & PAGE_MASK;
318 /* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
319 if (page_is_ram(start >> PAGE_SHIFT))
322 addr = (void __force *)ioremap_cache(start, PAGE_SIZE);
324 addr = (void *)((unsigned long)addr | (phys & ~PAGE_MASK));
329 void unxlate_dev_mem_ptr(unsigned long phys, void *addr)
331 if (page_is_ram(phys >> PAGE_SHIFT))
334 iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK));
338 static int __initdata early_ioremap_debug;
340 static int __init early_ioremap_debug_setup(char *str)
342 early_ioremap_debug = 1;
346 early_param("early_ioremap_debug", early_ioremap_debug_setup);
348 static __initdata int after_paging_init;
349 static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss;
351 static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
353 /* Don't assume we're using swapper_pg_dir at this point */
354 pgd_t *base = __va(read_cr3());
355 pgd_t *pgd = &base[pgd_index(addr)];
356 pud_t *pud = pud_offset(pgd, addr);
357 pmd_t *pmd = pmd_offset(pud, addr);
362 static inline pte_t * __init early_ioremap_pte(unsigned long addr)
364 return &bm_pte[pte_index(addr)];
367 static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata;
369 void __init early_ioremap_init(void)
374 if (early_ioremap_debug)
375 printk(KERN_INFO "early_ioremap_init()\n");
377 for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
378 slot_virt[i] = __fix_to_virt(FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*i);
380 pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
381 memset(bm_pte, 0, sizeof(bm_pte));
382 pmd_populate_kernel(&init_mm, pmd, bm_pte);
385 * The boot-ioremap range spans multiple pmds, for which
386 * we are not prepared:
388 if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
390 printk(KERN_WARNING "pmd %p != %p\n",
391 pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END)));
392 printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
393 fix_to_virt(FIX_BTMAP_BEGIN));
394 printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END): %08lx\n",
395 fix_to_virt(FIX_BTMAP_END));
397 printk(KERN_WARNING "FIX_BTMAP_END: %d\n", FIX_BTMAP_END);
398 printk(KERN_WARNING "FIX_BTMAP_BEGIN: %d\n",
403 void __init early_ioremap_reset(void)
405 after_paging_init = 1;
408 static void __init __early_set_fixmap(enum fixed_addresses idx,
409 phys_addr_t phys, pgprot_t flags)
411 unsigned long addr = __fix_to_virt(idx);
414 if (idx >= __end_of_fixed_addresses) {
418 pte = early_ioremap_pte(addr);
420 if (pgprot_val(flags))
421 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
423 pte_clear(&init_mm, addr, pte);
424 __flush_tlb_one(addr);
427 static inline void __init early_set_fixmap(enum fixed_addresses idx,
428 phys_addr_t phys, pgprot_t prot)
430 if (after_paging_init)
431 __set_fixmap(idx, phys, prot);
433 __early_set_fixmap(idx, phys, prot);
436 static inline void __init early_clear_fixmap(enum fixed_addresses idx)
438 if (after_paging_init)
441 __early_set_fixmap(idx, 0, __pgprot(0));
444 static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata;
445 static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;
447 static int __init check_early_ioremap_leak(void)
452 for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
459 "Debug warning: early ioremap leak of %d areas detected.\n",
462 "please boot with early_ioremap_debug and report the dmesg.\n");
466 late_initcall(check_early_ioremap_leak);
468 static void __init __iomem *
469 __early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
471 unsigned long offset;
472 resource_size_t last_addr;
473 unsigned int nrpages;
474 enum fixed_addresses idx0, idx;
477 WARN_ON(system_state != SYSTEM_BOOTING);
480 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
488 printk(KERN_INFO "early_iomap(%08llx, %08lx) not found slot\n",
489 (u64)phys_addr, size);
494 if (early_ioremap_debug) {
495 printk(KERN_INFO "early_ioremap(%08llx, %08lx) [%d] => ",
496 (u64)phys_addr, size, slot);
500 /* Don't allow wraparound or zero size */
501 last_addr = phys_addr + size - 1;
502 if (!size || last_addr < phys_addr) {
507 prev_size[slot] = size;
509 * Mappings have to be page-aligned
511 offset = phys_addr & ~PAGE_MASK;
512 phys_addr &= PAGE_MASK;
513 size = PAGE_ALIGN(last_addr + 1) - phys_addr;
516 * Mappings have to fit in the FIX_BTMAP area.
518 nrpages = size >> PAGE_SHIFT;
519 if (nrpages > NR_FIX_BTMAPS) {
527 idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
529 while (nrpages > 0) {
530 early_set_fixmap(idx, phys_addr, prot);
531 phys_addr += PAGE_SIZE;
535 if (early_ioremap_debug)
536 printk(KERN_CONT "%08lx + %08lx\n", offset, slot_virt[slot]);
538 prev_map[slot] = (void __iomem *)(offset + slot_virt[slot]);
539 return prev_map[slot];
542 /* Remap an IO device */
543 void __init __iomem *
544 early_ioremap(resource_size_t phys_addr, unsigned long size)
546 return __early_ioremap(phys_addr, size, PAGE_KERNEL_IO);
550 void __init __iomem *
551 early_memremap(resource_size_t phys_addr, unsigned long size)
553 return __early_ioremap(phys_addr, size, PAGE_KERNEL);
556 void __init early_iounmap(void __iomem *addr, unsigned long size)
558 unsigned long virt_addr;
559 unsigned long offset;
560 unsigned int nrpages;
561 enum fixed_addresses idx;
565 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
566 if (prev_map[i] == addr) {
573 printk(KERN_INFO "early_iounmap(%p, %08lx) not found slot\n",
579 if (prev_size[slot] != size) {
580 printk(KERN_INFO "early_iounmap(%p, %08lx) [%d] size not consistent %08lx\n",
581 addr, size, slot, prev_size[slot]);
586 if (early_ioremap_debug) {
587 printk(KERN_INFO "early_iounmap(%p, %08lx) [%d]\n", addr,
592 virt_addr = (unsigned long)addr;
593 if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)) {
597 offset = virt_addr & ~PAGE_MASK;
598 nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT;
600 idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
601 while (nrpages > 0) {
602 early_clear_fixmap(idx);
606 prev_map[slot] = NULL;