1 /*
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
5 *
6 * (C) Copyright 1995 1996 Linus Torvalds
7 */
8
9 #include <linux/bootmem.h>
10 #include <linux/init.h>
11 #include <linux/io.h>
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/vmalloc.h>
15 #include <linux/mmiotrace.h>
16
17 #include <asm/cacheflush.h>
18 #include <asm/e820.h>
19 #include <asm/fixmap.h>
20 #include <asm/pgtable.h>
21 #include <asm/tlbflush.h>
22 #include <asm/pgalloc.h>
23 #include <asm/pat.h>
24
25 #include "physaddr.h"
26
27 /*
28 * Fix up the linear direct mapping of the kernel to avoid cache attribute
29 * conflicts.
30 */
ioremap_change_attr(unsigned long vaddr,unsigned long size,unsigned long prot_val)31 int ioremap_change_attr(unsigned long vaddr, unsigned long size,
32 unsigned long prot_val)
33 {
34 unsigned long nrpages = size >> PAGE_SHIFT;
35 int err;
36
37 switch (prot_val) {
38 case _PAGE_CACHE_UC:
39 default:
40 err = _set_memory_uc(vaddr, nrpages);
41 break;
42 case _PAGE_CACHE_WC:
43 err = _set_memory_wc(vaddr, nrpages);
44 break;
45 case _PAGE_CACHE_WB:
46 err = _set_memory_wb(vaddr, nrpages);
47 break;
48 }
49
50 return err;
51 }
52
53 /*
54 * Remap an arbitrary physical address space into the kernel virtual
55 * address space. Needed when the kernel wants to access high addresses
56 * directly.
57 *
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.
61 */
__ioremap_caller(resource_size_t phys_addr,unsigned long size,unsigned long prot_val,void * caller)62 static void __iomem *__ioremap_caller(resource_size_t phys_addr,
63 unsigned long size, unsigned long prot_val, void *caller)
64 {
65 unsigned long offset, vaddr;
66 resource_size_t pfn, last_pfn, 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;
71 pgprot_t prot;
72 int retval;
73 void __iomem *ret_addr;
74
75 /* Don't allow wraparound or zero size */
76 last_addr = phys_addr + size - 1;
77 if (!size || last_addr < phys_addr)
78 return NULL;
79
80 if (!phys_addr_valid(phys_addr)) {
81 printk(KERN_WARNING "ioremap: invalid physical address %llx\n",
82 (unsigned long long)phys_addr);
83 WARN_ON_ONCE(1);
84 return NULL;
85 }
86
87 /*
88 * Don't remap the low PCI/ISA area, it's always mapped..
89 */
90 if (is_ISA_range(phys_addr, last_addr))
91 return (__force void __iomem *)phys_to_virt(phys_addr);
92
93 /*
94 * Don't allow anybody to remap normal RAM that we're using..
95 */
96 last_pfn = last_addr >> PAGE_SHIFT;
97 for (pfn = phys_addr >> PAGE_SHIFT; pfn <= last_pfn; pfn++) {
98 int is_ram = page_is_ram(pfn);
99
100 if (is_ram && pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn)))
101 return NULL;
102 WARN_ON_ONCE(is_ram);
103 }
104
105 /*
106 * Mappings have to be page-aligned
107 */
108 offset = phys_addr & ~PAGE_MASK;
109 phys_addr &= PHYSICAL_PAGE_MASK;
110 size = PAGE_ALIGN(last_addr+1) - phys_addr;
111
112 retval = reserve_memtype(phys_addr, (u64)phys_addr + size,
113 prot_val, &new_prot_val);
114 if (retval) {
115 printk(KERN_ERR "ioremap reserve_memtype failed %d\n", retval);
116 return NULL;
117 }
118
119 if (prot_val != new_prot_val) {
120 if (!is_new_memtype_allowed(phys_addr, size,
121 prot_val, new_prot_val)) {
122 printk(KERN_ERR
123 "ioremap error for 0x%llx-0x%llx, requested 0x%lx, got 0x%lx\n",
124 (unsigned long long)phys_addr,
125 (unsigned long long)(phys_addr + size),
126 prot_val, new_prot_val);
127 goto err_free_memtype;
128 }
129 prot_val = new_prot_val;
130 }
131
132 switch (prot_val) {
133 case _PAGE_CACHE_UC:
134 default:
135 prot = PAGE_KERNEL_IO_NOCACHE;
136 break;
137 case _PAGE_CACHE_UC_MINUS:
138 prot = PAGE_KERNEL_IO_UC_MINUS;
139 break;
140 case _PAGE_CACHE_WC:
141 prot = PAGE_KERNEL_IO_WC;
142 break;
143 case _PAGE_CACHE_WB:
144 prot = PAGE_KERNEL_IO;
145 break;
146 }
147
148 /*
149 * Ok, go for it..
150 */
151 area = get_vm_area_caller(size, VM_IOREMAP, caller);
152 if (!area)
153 goto err_free_memtype;
154 area->phys_addr = phys_addr;
155 vaddr = (unsigned long) area->addr;
156
157 if (kernel_map_sync_memtype(phys_addr, size, prot_val))
158 goto err_free_area;
159
160 if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot))
161 goto err_free_area;
162
163 ret_addr = (void __iomem *) (vaddr + offset);
164 mmiotrace_ioremap(unaligned_phys_addr, unaligned_size, ret_addr);
165
166 /*
167 * Check if the request spans more than any BAR in the iomem resource
168 * tree.
169 */
170 WARN_ONCE(iomem_map_sanity_check(unaligned_phys_addr, unaligned_size),
171 KERN_INFO "Info: mapping multiple BARs. Your kernel is fine.");
172
173 return ret_addr;
174 err_free_area:
175 free_vm_area(area);
176 err_free_memtype:
177 free_memtype(phys_addr, phys_addr + size);
178 return NULL;
179 }
180
181 /**
182 * ioremap_nocache - map bus memory into CPU space
183 * @phys_addr: bus address of the memory
184 * @size: size of the resource to map
185 *
186 * ioremap_nocache performs a platform specific sequence of operations to
187 * make bus memory CPU accessible via the readb/readw/readl/writeb/
188 * writew/writel functions and the other mmio helpers. The returned
189 * address is not guaranteed to be usable directly as a virtual
190 * address.
191 *
192 * This version of ioremap ensures that the memory is marked uncachable
193 * on the CPU as well as honouring existing caching rules from things like
194 * the PCI bus. Note that there are other caches and buffers on many
195 * busses. In particular driver authors should read up on PCI writes
196 *
197 * It's useful if some control registers are in such an area and
198 * write combining or read caching is not desirable:
199 *
200 * Must be freed with iounmap.
201 */
ioremap_nocache(resource_size_t phys_addr,unsigned long size)202 void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size)
203 {
204 /*
205 * Ideally, this should be:
206 * pat_enabled ? _PAGE_CACHE_UC : _PAGE_CACHE_UC_MINUS;
207 *
208 * Till we fix all X drivers to use ioremap_wc(), we will use
209 * UC MINUS.
210 */
211 unsigned long val = _PAGE_CACHE_UC_MINUS;
212
213 return __ioremap_caller(phys_addr, size, val,
214 __builtin_return_address(0));
215 }
216 EXPORT_SYMBOL(ioremap_nocache);
217
218 /**
219 * ioremap_wc - map memory into CPU space write combined
220 * @phys_addr: bus address of the memory
221 * @size: size of the resource to map
222 *
223 * This version of ioremap ensures that the memory is marked write combining.
224 * Write combining allows faster writes to some hardware devices.
225 *
226 * Must be freed with iounmap.
227 */
ioremap_wc(resource_size_t phys_addr,unsigned long size)228 void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size)
229 {
230 if (pat_enabled)
231 return __ioremap_caller(phys_addr, size, _PAGE_CACHE_WC,
232 __builtin_return_address(0));
233 else
234 return ioremap_nocache(phys_addr, size);
235 }
236 EXPORT_SYMBOL(ioremap_wc);
237
ioremap_cache(resource_size_t phys_addr,unsigned long size)238 void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
239 {
240 return __ioremap_caller(phys_addr, size, _PAGE_CACHE_WB,
241 __builtin_return_address(0));
242 }
243 EXPORT_SYMBOL(ioremap_cache);
244
ioremap_prot(resource_size_t phys_addr,unsigned long size,unsigned long prot_val)245 void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
246 unsigned long prot_val)
247 {
248 return __ioremap_caller(phys_addr, size, (prot_val & _PAGE_CACHE_MASK),
249 __builtin_return_address(0));
250 }
251 EXPORT_SYMBOL(ioremap_prot);
252
253 /**
254 * iounmap - Free a IO remapping
255 * @addr: virtual address from ioremap_*
256 *
257 * Caller must ensure there is only one unmapping for the same pointer.
258 */
iounmap(volatile void __iomem * addr)259 void iounmap(volatile void __iomem *addr)
260 {
261 struct vm_struct *p, *o;
262
263 if ((void __force *)addr <= high_memory)
264 return;
265
266 /*
267 * __ioremap special-cases the PCI/ISA range by not instantiating a
268 * vm_area and by simply returning an address into the kernel mapping
269 * of ISA space. So handle that here.
270 */
271 if ((void __force *)addr >= phys_to_virt(ISA_START_ADDRESS) &&
272 (void __force *)addr < phys_to_virt(ISA_END_ADDRESS))
273 return;
274
275 addr = (volatile void __iomem *)
276 (PAGE_MASK & (unsigned long __force)addr);
277
278 mmiotrace_iounmap(addr);
279
280 /* Use the vm area unlocked, assuming the caller
281 ensures there isn't another iounmap for the same address
282 in parallel. Reuse of the virtual address is prevented by
283 leaving it in the global lists until we're done with it.
284 cpa takes care of the direct mappings. */
285 p = find_vm_area((void __force *)addr);
286
287 if (!p) {
288 printk(KERN_ERR "iounmap: bad address %p\n", addr);
289 dump_stack();
290 return;
291 }
292
293 free_memtype(p->phys_addr, p->phys_addr + get_vm_area_size(p));
294
295 /* Finally remove it */
296 o = remove_vm_area((void __force *)addr);
297 BUG_ON(p != o || o == NULL);
298 kfree(p);
299 }
300 EXPORT_SYMBOL(iounmap);
301
302 /*
303 * Convert a physical pointer to a virtual kernel pointer for /dev/mem
304 * access
305 */
xlate_dev_mem_ptr(unsigned long phys)306 void *xlate_dev_mem_ptr(unsigned long phys)
307 {
308 void *addr;
309 unsigned long start = phys & PAGE_MASK;
310
311 /* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
312 if (page_is_ram(start >> PAGE_SHIFT))
313 return __va(phys);
314
315 addr = (void __force *)ioremap_cache(start, PAGE_SIZE);
316 if (addr)
317 addr = (void *)((unsigned long)addr | (phys & ~PAGE_MASK));
318
319 return addr;
320 }
321
unxlate_dev_mem_ptr(unsigned long phys,void * addr)322 void unxlate_dev_mem_ptr(unsigned long phys, void *addr)
323 {
324 if (page_is_ram(phys >> PAGE_SHIFT))
325 return;
326
327 iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK));
328 return;
329 }
330
331 static int __initdata early_ioremap_debug;
332
early_ioremap_debug_setup(char * str)333 static int __init early_ioremap_debug_setup(char *str)
334 {
335 early_ioremap_debug = 1;
336
337 return 0;
338 }
339 early_param("early_ioremap_debug", early_ioremap_debug_setup);
340
341 static __initdata int after_paging_init;
342 static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss;
343
early_ioremap_pmd(unsigned long addr)344 static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
345 {
346 /* Don't assume we're using swapper_pg_dir at this point */
347 pgd_t *base = __va(read_cr3());
348 pgd_t *pgd = &base[pgd_index(addr)];
349 pud_t *pud = pud_offset(pgd, addr);
350 pmd_t *pmd = pmd_offset(pud, addr);
351
352 return pmd;
353 }
354
early_ioremap_pte(unsigned long addr)355 static inline pte_t * __init early_ioremap_pte(unsigned long addr)
356 {
357 return &bm_pte[pte_index(addr)];
358 }
359
is_early_ioremap_ptep(pte_t * ptep)360 bool __init is_early_ioremap_ptep(pte_t *ptep)
361 {
362 return ptep >= &bm_pte[0] && ptep < &bm_pte[PAGE_SIZE/sizeof(pte_t)];
363 }
364
365 static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata;
366
early_ioremap_init(void)367 void __init early_ioremap_init(void)
368 {
369 pmd_t *pmd;
370 int i;
371
372 if (early_ioremap_debug)
373 printk(KERN_INFO "early_ioremap_init()\n");
374
375 for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
376 slot_virt[i] = __fix_to_virt(FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*i);
377
378 pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
379 memset(bm_pte, 0, sizeof(bm_pte));
380 pmd_populate_kernel(&init_mm, pmd, bm_pte);
381
382 /*
383 * The boot-ioremap range spans multiple pmds, for which
384 * we are not prepared:
385 */
386 #define __FIXADDR_TOP (-PAGE_SIZE)
387 BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
388 != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
389 #undef __FIXADDR_TOP
390 if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
391 WARN_ON(1);
392 printk(KERN_WARNING "pmd %p != %p\n",
393 pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END)));
394 printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
395 fix_to_virt(FIX_BTMAP_BEGIN));
396 printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END): %08lx\n",
397 fix_to_virt(FIX_BTMAP_END));
398
399 printk(KERN_WARNING "FIX_BTMAP_END: %d\n", FIX_BTMAP_END);
400 printk(KERN_WARNING "FIX_BTMAP_BEGIN: %d\n",
401 FIX_BTMAP_BEGIN);
402 }
403 }
404
early_ioremap_reset(void)405 void __init early_ioremap_reset(void)
406 {
407 after_paging_init = 1;
408 }
409
__early_set_fixmap(enum fixed_addresses idx,phys_addr_t phys,pgprot_t flags)410 static void __init __early_set_fixmap(enum fixed_addresses idx,
411 phys_addr_t phys, pgprot_t flags)
412 {
413 unsigned long addr = __fix_to_virt(idx);
414 pte_t *pte;
415
416 if (idx >= __end_of_fixed_addresses) {
417 BUG();
418 return;
419 }
420 pte = early_ioremap_pte(addr);
421
422 if (pgprot_val(flags))
423 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
424 else
425 pte_clear(&init_mm, addr, pte);
426 __flush_tlb_one(addr);
427 }
428
early_set_fixmap(enum fixed_addresses idx,phys_addr_t phys,pgprot_t prot)429 static inline void __init early_set_fixmap(enum fixed_addresses idx,
430 phys_addr_t phys, pgprot_t prot)
431 {
432 if (after_paging_init)
433 __set_fixmap(idx, phys, prot);
434 else
435 __early_set_fixmap(idx, phys, prot);
436 }
437
early_clear_fixmap(enum fixed_addresses idx)438 static inline void __init early_clear_fixmap(enum fixed_addresses idx)
439 {
440 if (after_paging_init)
441 clear_fixmap(idx);
442 else
443 __early_set_fixmap(idx, 0, __pgprot(0));
444 }
445
446 static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata;
447 static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;
448
fixup_early_ioremap(void)449 void __init fixup_early_ioremap(void)
450 {
451 int i;
452
453 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
454 if (prev_map[i]) {
455 WARN_ON(1);
456 break;
457 }
458 }
459
460 early_ioremap_init();
461 }
462
check_early_ioremap_leak(void)463 static int __init check_early_ioremap_leak(void)
464 {
465 int count = 0;
466 int i;
467
468 for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
469 if (prev_map[i])
470 count++;
471
472 if (!count)
473 return 0;
474 WARN(1, KERN_WARNING
475 "Debug warning: early ioremap leak of %d areas detected.\n",
476 count);
477 printk(KERN_WARNING
478 "please boot with early_ioremap_debug and report the dmesg.\n");
479
480 return 1;
481 }
482 late_initcall(check_early_ioremap_leak);
483
484 static void __init __iomem *
__early_ioremap(resource_size_t phys_addr,unsigned long size,pgprot_t prot)485 __early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
486 {
487 unsigned long offset;
488 resource_size_t last_addr;
489 unsigned int nrpages;
490 enum fixed_addresses idx0, idx;
491 int i, slot;
492
493 WARN_ON(system_state != SYSTEM_BOOTING);
494
495 slot = -1;
496 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
497 if (!prev_map[i]) {
498 slot = i;
499 break;
500 }
501 }
502
503 if (slot < 0) {
504 printk(KERN_INFO "early_iomap(%08llx, %08lx) not found slot\n",
505 (u64)phys_addr, size);
506 WARN_ON(1);
507 return NULL;
508 }
509
510 if (early_ioremap_debug) {
511 printk(KERN_INFO "early_ioremap(%08llx, %08lx) [%d] => ",
512 (u64)phys_addr, size, slot);
513 dump_stack();
514 }
515
516 /* Don't allow wraparound or zero size */
517 last_addr = phys_addr + size - 1;
518 if (!size || last_addr < phys_addr) {
519 WARN_ON(1);
520 return NULL;
521 }
522
523 prev_size[slot] = size;
524 /*
525 * Mappings have to be page-aligned
526 */
527 offset = phys_addr & ~PAGE_MASK;
528 phys_addr &= PAGE_MASK;
529 size = PAGE_ALIGN(last_addr + 1) - phys_addr;
530
531 /*
532 * Mappings have to fit in the FIX_BTMAP area.
533 */
534 nrpages = size >> PAGE_SHIFT;
535 if (nrpages > NR_FIX_BTMAPS) {
536 WARN_ON(1);
537 return NULL;
538 }
539
540 /*
541 * Ok, go for it..
542 */
543 idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
544 idx = idx0;
545 while (nrpages > 0) {
546 early_set_fixmap(idx, phys_addr, prot);
547 phys_addr += PAGE_SIZE;
548 --idx;
549 --nrpages;
550 }
551 if (early_ioremap_debug)
552 printk(KERN_CONT "%08lx + %08lx\n", offset, slot_virt[slot]);
553
554 prev_map[slot] = (void __iomem *)(offset + slot_virt[slot]);
555 return prev_map[slot];
556 }
557
558 /* Remap an IO device */
559 void __init __iomem *
early_ioremap(resource_size_t phys_addr,unsigned long size)560 early_ioremap(resource_size_t phys_addr, unsigned long size)
561 {
562 return __early_ioremap(phys_addr, size, PAGE_KERNEL_IO);
563 }
564
565 /* Remap memory */
566 void __init __iomem *
early_memremap(resource_size_t phys_addr,unsigned long size)567 early_memremap(resource_size_t phys_addr, unsigned long size)
568 {
569 return __early_ioremap(phys_addr, size, PAGE_KERNEL);
570 }
571
early_iounmap(void __iomem * addr,unsigned long size)572 void __init early_iounmap(void __iomem *addr, unsigned long size)
573 {
574 unsigned long virt_addr;
575 unsigned long offset;
576 unsigned int nrpages;
577 enum fixed_addresses idx;
578 int i, slot;
579
580 slot = -1;
581 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
582 if (prev_map[i] == addr) {
583 slot = i;
584 break;
585 }
586 }
587
588 if (slot < 0) {
589 printk(KERN_INFO "early_iounmap(%p, %08lx) not found slot\n",
590 addr, size);
591 WARN_ON(1);
592 return;
593 }
594
595 if (prev_size[slot] != size) {
596 printk(KERN_INFO "early_iounmap(%p, %08lx) [%d] size not consistent %08lx\n",
597 addr, size, slot, prev_size[slot]);
598 WARN_ON(1);
599 return;
600 }
601
602 if (early_ioremap_debug) {
603 printk(KERN_INFO "early_iounmap(%p, %08lx) [%d]\n", addr,
604 size, slot);
605 dump_stack();
606 }
607
608 virt_addr = (unsigned long)addr;
609 if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)) {
610 WARN_ON(1);
611 return;
612 }
613 offset = virt_addr & ~PAGE_MASK;
614 nrpages = PAGE_ALIGN(offset + size) >> PAGE_SHIFT;
615
616 idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
617 while (nrpages > 0) {
618 early_clear_fixmap(idx);
619 --idx;
620 --nrpages;
621 }
622 prev_map[slot] = NULL;
623 }
624