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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 #ifdef CONFIG_X86_64
26 
phys_addr_valid(unsigned long addr)27 static inline int phys_addr_valid(unsigned long addr)
28 {
29 	return addr < (1UL << boot_cpu_data.x86_phys_bits);
30 }
31 
__phys_addr(unsigned long x)32 unsigned long __phys_addr(unsigned long x)
33 {
34 	if (x >= __START_KERNEL_map) {
35 		x -= __START_KERNEL_map;
36 		VIRTUAL_BUG_ON(x >= KERNEL_IMAGE_SIZE);
37 		x += phys_base;
38 	} else {
39 		VIRTUAL_BUG_ON(x < PAGE_OFFSET);
40 		x -= PAGE_OFFSET;
41 		VIRTUAL_BUG_ON(system_state == SYSTEM_BOOTING ? x > MAXMEM :
42 					!phys_addr_valid(x));
43 	}
44 	return x;
45 }
46 EXPORT_SYMBOL(__phys_addr);
47 
__virt_addr_valid(unsigned long x)48 bool __virt_addr_valid(unsigned long x)
49 {
50 	if (x >= __START_KERNEL_map) {
51 		x -= __START_KERNEL_map;
52 		if (x >= KERNEL_IMAGE_SIZE)
53 			return false;
54 		x += phys_base;
55 	} else {
56 		if (x < PAGE_OFFSET)
57 			return false;
58 		x -= PAGE_OFFSET;
59 		if (system_state == SYSTEM_BOOTING ?
60 				x > MAXMEM : !phys_addr_valid(x)) {
61 			return false;
62 		}
63 	}
64 
65 	return pfn_valid(x >> PAGE_SHIFT);
66 }
67 EXPORT_SYMBOL(__virt_addr_valid);
68 
69 #else
70 
phys_addr_valid(unsigned long addr)71 static inline int phys_addr_valid(unsigned long addr)
72 {
73 	return 1;
74 }
75 
76 #ifdef CONFIG_DEBUG_VIRTUAL
__phys_addr(unsigned long x)77 unsigned long __phys_addr(unsigned long x)
78 {
79 	/* VMALLOC_* aren't constants; not available at the boot time */
80 	VIRTUAL_BUG_ON(x < PAGE_OFFSET);
81 	VIRTUAL_BUG_ON(system_state != SYSTEM_BOOTING &&
82 		is_vmalloc_addr((void *) x));
83 	return x - PAGE_OFFSET;
84 }
85 EXPORT_SYMBOL(__phys_addr);
86 #endif
87 
__virt_addr_valid(unsigned long x)88 bool __virt_addr_valid(unsigned long x)
89 {
90 	if (x < PAGE_OFFSET)
91 		return false;
92 	if (system_state != SYSTEM_BOOTING && is_vmalloc_addr((void *) x))
93 		return false;
94 	return pfn_valid((x - PAGE_OFFSET) >> PAGE_SHIFT);
95 }
96 EXPORT_SYMBOL(__virt_addr_valid);
97 
98 #endif
99 
page_is_ram(unsigned long pagenr)100 int page_is_ram(unsigned long pagenr)
101 {
102 	resource_size_t addr, end;
103 	int i;
104 
105 	/*
106 	 * A special case is the first 4Kb of memory;
107 	 * This is a BIOS owned area, not kernel ram, but generally
108 	 * not listed as such in the E820 table.
109 	 */
110 	if (pagenr == 0)
111 		return 0;
112 
113 	/*
114 	 * Second special case: Some BIOSen report the PC BIOS
115 	 * area (640->1Mb) as ram even though it is not.
116 	 */
117 	if (pagenr >= (BIOS_BEGIN >> PAGE_SHIFT) &&
118 		    pagenr < (BIOS_END >> PAGE_SHIFT))
119 		return 0;
120 
121 	for (i = 0; i < e820.nr_map; i++) {
122 		/*
123 		 * Not usable memory:
124 		 */
125 		if (e820.map[i].type != E820_RAM)
126 			continue;
127 		addr = (e820.map[i].addr + PAGE_SIZE-1) >> PAGE_SHIFT;
128 		end = (e820.map[i].addr + e820.map[i].size) >> PAGE_SHIFT;
129 
130 
131 		if ((pagenr >= addr) && (pagenr < end))
132 			return 1;
133 	}
134 	return 0;
135 }
136 
137 /*
138  * Fix up the linear direct mapping of the kernel to avoid cache attribute
139  * conflicts.
140  */
ioremap_change_attr(unsigned long vaddr,unsigned long size,unsigned long prot_val)141 int ioremap_change_attr(unsigned long vaddr, unsigned long size,
142 			       unsigned long prot_val)
143 {
144 	unsigned long nrpages = size >> PAGE_SHIFT;
145 	int err;
146 
147 	switch (prot_val) {
148 	case _PAGE_CACHE_UC:
149 	default:
150 		err = _set_memory_uc(vaddr, nrpages);
151 		break;
152 	case _PAGE_CACHE_WC:
153 		err = _set_memory_wc(vaddr, nrpages);
154 		break;
155 	case _PAGE_CACHE_WB:
156 		err = _set_memory_wb(vaddr, nrpages);
157 		break;
158 	}
159 
160 	return err;
161 }
162 
163 /*
164  * Remap an arbitrary physical address space into the kernel virtual
165  * address space. Needed when the kernel wants to access high addresses
166  * directly.
167  *
168  * NOTE! We need to allow non-page-aligned mappings too: we will obviously
169  * have to convert them into an offset in a page-aligned mapping, but the
170  * caller shouldn't need to know that small detail.
171  */
__ioremap_caller(resource_size_t phys_addr,unsigned long size,unsigned long prot_val,void * caller)172 static void __iomem *__ioremap_caller(resource_size_t phys_addr,
173 		unsigned long size, unsigned long prot_val, void *caller)
174 {
175 	unsigned long pfn, offset, vaddr;
176 	resource_size_t last_addr;
177 	const resource_size_t unaligned_phys_addr = phys_addr;
178 	const unsigned long unaligned_size = size;
179 	struct vm_struct *area;
180 	unsigned long new_prot_val;
181 	pgprot_t prot;
182 	int retval;
183 	void __iomem *ret_addr;
184 
185 	/* Don't allow wraparound or zero size */
186 	last_addr = phys_addr + size - 1;
187 	if (!size || last_addr < phys_addr)
188 		return NULL;
189 
190 	if (!phys_addr_valid(phys_addr)) {
191 		printk(KERN_WARNING "ioremap: invalid physical address %llx\n",
192 		       (unsigned long long)phys_addr);
193 		WARN_ON_ONCE(1);
194 		return NULL;
195 	}
196 
197 	/*
198 	 * Don't remap the low PCI/ISA area, it's always mapped..
199 	 */
200 	if (is_ISA_range(phys_addr, last_addr))
201 		return (__force void __iomem *)phys_to_virt(phys_addr);
202 
203 	/*
204 	 * Check if the request spans more than any BAR in the iomem resource
205 	 * tree.
206 	 */
207 	WARN_ONCE(iomem_map_sanity_check(phys_addr, size),
208 		  KERN_INFO "Info: mapping multiple BARs. Your kernel is fine.");
209 
210 	/*
211 	 * Don't allow anybody to remap normal RAM that we're using..
212 	 */
213 	for (pfn = phys_addr >> PAGE_SHIFT;
214 				(pfn << PAGE_SHIFT) < (last_addr & PAGE_MASK);
215 				pfn++) {
216 
217 		int is_ram = page_is_ram(pfn);
218 
219 		if (is_ram && pfn_valid(pfn) && !PageReserved(pfn_to_page(pfn)))
220 			return NULL;
221 		WARN_ON_ONCE(is_ram);
222 	}
223 
224 	/*
225 	 * Mappings have to be page-aligned
226 	 */
227 	offset = phys_addr & ~PAGE_MASK;
228 	phys_addr &= PAGE_MASK;
229 	size = PAGE_ALIGN(last_addr+1) - phys_addr;
230 
231 	retval = reserve_memtype(phys_addr, (u64)phys_addr + size,
232 						prot_val, &new_prot_val);
233 	if (retval) {
234 		pr_debug("Warning: reserve_memtype returned %d\n", retval);
235 		return NULL;
236 	}
237 
238 	if (prot_val != new_prot_val) {
239 		/*
240 		 * Do not fallback to certain memory types with certain
241 		 * requested type:
242 		 * - request is uc-, return cannot be write-back
243 		 * - request is uc-, return cannot be write-combine
244 		 * - request is write-combine, return cannot be write-back
245 		 */
246 		if ((prot_val == _PAGE_CACHE_UC_MINUS &&
247 		     (new_prot_val == _PAGE_CACHE_WB ||
248 		      new_prot_val == _PAGE_CACHE_WC)) ||
249 		    (prot_val == _PAGE_CACHE_WC &&
250 		     new_prot_val == _PAGE_CACHE_WB)) {
251 			pr_debug(
252 		"ioremap error for 0x%llx-0x%llx, requested 0x%lx, got 0x%lx\n",
253 				(unsigned long long)phys_addr,
254 				(unsigned long long)(phys_addr + size),
255 				prot_val, new_prot_val);
256 			free_memtype(phys_addr, phys_addr + size);
257 			return NULL;
258 		}
259 		prot_val = new_prot_val;
260 	}
261 
262 	switch (prot_val) {
263 	case _PAGE_CACHE_UC:
264 	default:
265 		prot = PAGE_KERNEL_IO_NOCACHE;
266 		break;
267 	case _PAGE_CACHE_UC_MINUS:
268 		prot = PAGE_KERNEL_IO_UC_MINUS;
269 		break;
270 	case _PAGE_CACHE_WC:
271 		prot = PAGE_KERNEL_IO_WC;
272 		break;
273 	case _PAGE_CACHE_WB:
274 		prot = PAGE_KERNEL_IO;
275 		break;
276 	}
277 
278 	/*
279 	 * Ok, go for it..
280 	 */
281 	area = get_vm_area_caller(size, VM_IOREMAP, caller);
282 	if (!area)
283 		return NULL;
284 	area->phys_addr = phys_addr;
285 	vaddr = (unsigned long) area->addr;
286 	if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
287 		free_memtype(phys_addr, phys_addr + size);
288 		free_vm_area(area);
289 		return NULL;
290 	}
291 
292 	if (ioremap_change_attr(vaddr, size, prot_val) < 0) {
293 		free_memtype(phys_addr, phys_addr + size);
294 		vunmap(area->addr);
295 		return NULL;
296 	}
297 
298 	ret_addr = (void __iomem *) (vaddr + offset);
299 	mmiotrace_ioremap(unaligned_phys_addr, unaligned_size, ret_addr);
300 
301 	return ret_addr;
302 }
303 
304 /**
305  * ioremap_nocache     -   map bus memory into CPU space
306  * @offset:    bus address of the memory
307  * @size:      size of the resource to map
308  *
309  * ioremap_nocache performs a platform specific sequence of operations to
310  * make bus memory CPU accessible via the readb/readw/readl/writeb/
311  * writew/writel functions and the other mmio helpers. The returned
312  * address is not guaranteed to be usable directly as a virtual
313  * address.
314  *
315  * This version of ioremap ensures that the memory is marked uncachable
316  * on the CPU as well as honouring existing caching rules from things like
317  * the PCI bus. Note that there are other caches and buffers on many
318  * busses. In particular driver authors should read up on PCI writes
319  *
320  * It's useful if some control registers are in such an area and
321  * write combining or read caching is not desirable:
322  *
323  * Must be freed with iounmap.
324  */
ioremap_nocache(resource_size_t phys_addr,unsigned long size)325 void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size)
326 {
327 	/*
328 	 * Ideally, this should be:
329 	 *	pat_enabled ? _PAGE_CACHE_UC : _PAGE_CACHE_UC_MINUS;
330 	 *
331 	 * Till we fix all X drivers to use ioremap_wc(), we will use
332 	 * UC MINUS.
333 	 */
334 	unsigned long val = _PAGE_CACHE_UC_MINUS;
335 
336 	return __ioremap_caller(phys_addr, size, val,
337 				__builtin_return_address(0));
338 }
339 EXPORT_SYMBOL(ioremap_nocache);
340 
341 /**
342  * ioremap_wc	-	map memory into CPU space write combined
343  * @offset:	bus address of the memory
344  * @size:	size of the resource to map
345  *
346  * This version of ioremap ensures that the memory is marked write combining.
347  * Write combining allows faster writes to some hardware devices.
348  *
349  * Must be freed with iounmap.
350  */
ioremap_wc(unsigned long phys_addr,unsigned long size)351 void __iomem *ioremap_wc(unsigned long phys_addr, unsigned long size)
352 {
353 	if (pat_enabled)
354 		return __ioremap_caller(phys_addr, size, _PAGE_CACHE_WC,
355 					__builtin_return_address(0));
356 	else
357 		return ioremap_nocache(phys_addr, size);
358 }
359 EXPORT_SYMBOL(ioremap_wc);
360 
ioremap_cache(resource_size_t phys_addr,unsigned long size)361 void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
362 {
363 	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_WB,
364 				__builtin_return_address(0));
365 }
366 EXPORT_SYMBOL(ioremap_cache);
367 
ioremap_default(resource_size_t phys_addr,unsigned long size)368 static void __iomem *ioremap_default(resource_size_t phys_addr,
369 					unsigned long size)
370 {
371 	unsigned long flags;
372 	void __iomem *ret;
373 	int err;
374 
375 	/*
376 	 * - WB for WB-able memory and no other conflicting mappings
377 	 * - UC_MINUS for non-WB-able memory with no other conflicting mappings
378 	 * - Inherit from confliting mappings otherwise
379 	 */
380 	err = reserve_memtype(phys_addr, phys_addr + size, -1, &flags);
381 	if (err < 0)
382 		return NULL;
383 
384 	ret = __ioremap_caller(phys_addr, size, flags,
385 			       __builtin_return_address(0));
386 
387 	free_memtype(phys_addr, phys_addr + size);
388 	return ret;
389 }
390 
ioremap_prot(resource_size_t phys_addr,unsigned long size,unsigned long prot_val)391 void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
392 				unsigned long prot_val)
393 {
394 	return __ioremap_caller(phys_addr, size, (prot_val & _PAGE_CACHE_MASK),
395 				__builtin_return_address(0));
396 }
397 EXPORT_SYMBOL(ioremap_prot);
398 
399 /**
400  * iounmap - Free a IO remapping
401  * @addr: virtual address from ioremap_*
402  *
403  * Caller must ensure there is only one unmapping for the same pointer.
404  */
iounmap(volatile void __iomem * addr)405 void iounmap(volatile void __iomem *addr)
406 {
407 	struct vm_struct *p, *o;
408 
409 	if ((void __force *)addr <= high_memory)
410 		return;
411 
412 	/*
413 	 * __ioremap special-cases the PCI/ISA range by not instantiating a
414 	 * vm_area and by simply returning an address into the kernel mapping
415 	 * of ISA space.   So handle that here.
416 	 */
417 	if ((void __force *)addr >= phys_to_virt(ISA_START_ADDRESS) &&
418 	    (void __force *)addr < phys_to_virt(ISA_END_ADDRESS))
419 		return;
420 
421 	addr = (volatile void __iomem *)
422 		(PAGE_MASK & (unsigned long __force)addr);
423 
424 	mmiotrace_iounmap(addr);
425 
426 	/* Use the vm area unlocked, assuming the caller
427 	   ensures there isn't another iounmap for the same address
428 	   in parallel. Reuse of the virtual address is prevented by
429 	   leaving it in the global lists until we're done with it.
430 	   cpa takes care of the direct mappings. */
431 	read_lock(&vmlist_lock);
432 	for (p = vmlist; p; p = p->next) {
433 		if (p->addr == (void __force *)addr)
434 			break;
435 	}
436 	read_unlock(&vmlist_lock);
437 
438 	if (!p) {
439 		printk(KERN_ERR "iounmap: bad address %p\n", addr);
440 		dump_stack();
441 		return;
442 	}
443 
444 	free_memtype(p->phys_addr, p->phys_addr + get_vm_area_size(p));
445 
446 	/* Finally remove it */
447 	o = remove_vm_area((void __force *)addr);
448 	BUG_ON(p != o || o == NULL);
449 	kfree(p);
450 }
451 EXPORT_SYMBOL(iounmap);
452 
453 /*
454  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
455  * access
456  */
xlate_dev_mem_ptr(unsigned long phys)457 void *xlate_dev_mem_ptr(unsigned long phys)
458 {
459 	void *addr;
460 	unsigned long start = phys & PAGE_MASK;
461 
462 	/* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
463 	if (page_is_ram(start >> PAGE_SHIFT))
464 		return __va(phys);
465 
466 	addr = (void __force *)ioremap_default(start, PAGE_SIZE);
467 	if (addr)
468 		addr = (void *)((unsigned long)addr | (phys & ~PAGE_MASK));
469 
470 	return addr;
471 }
472 
unxlate_dev_mem_ptr(unsigned long phys,void * addr)473 void unxlate_dev_mem_ptr(unsigned long phys, void *addr)
474 {
475 	if (page_is_ram(phys >> PAGE_SHIFT))
476 		return;
477 
478 	iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK));
479 	return;
480 }
481 
482 static int __initdata early_ioremap_debug;
483 
early_ioremap_debug_setup(char * str)484 static int __init early_ioremap_debug_setup(char *str)
485 {
486 	early_ioremap_debug = 1;
487 
488 	return 0;
489 }
490 early_param("early_ioremap_debug", early_ioremap_debug_setup);
491 
492 static __initdata int after_paging_init;
493 static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss;
494 
early_ioremap_pmd(unsigned long addr)495 static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
496 {
497 	/* Don't assume we're using swapper_pg_dir at this point */
498 	pgd_t *base = __va(read_cr3());
499 	pgd_t *pgd = &base[pgd_index(addr)];
500 	pud_t *pud = pud_offset(pgd, addr);
501 	pmd_t *pmd = pmd_offset(pud, addr);
502 
503 	return pmd;
504 }
505 
early_ioremap_pte(unsigned long addr)506 static inline pte_t * __init early_ioremap_pte(unsigned long addr)
507 {
508 	return &bm_pte[pte_index(addr)];
509 }
510 
early_ioremap_init(void)511 void __init early_ioremap_init(void)
512 {
513 	pmd_t *pmd;
514 
515 	if (early_ioremap_debug)
516 		printk(KERN_INFO "early_ioremap_init()\n");
517 
518 	pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
519 	memset(bm_pte, 0, sizeof(bm_pte));
520 	pmd_populate_kernel(&init_mm, pmd, bm_pte);
521 
522 	/*
523 	 * The boot-ioremap range spans multiple pmds, for which
524 	 * we are not prepared:
525 	 */
526 	if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
527 		WARN_ON(1);
528 		printk(KERN_WARNING "pmd %p != %p\n",
529 		       pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END)));
530 		printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
531 			fix_to_virt(FIX_BTMAP_BEGIN));
532 		printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END):   %08lx\n",
533 			fix_to_virt(FIX_BTMAP_END));
534 
535 		printk(KERN_WARNING "FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
536 		printk(KERN_WARNING "FIX_BTMAP_BEGIN:     %d\n",
537 		       FIX_BTMAP_BEGIN);
538 	}
539 }
540 
early_ioremap_reset(void)541 void __init early_ioremap_reset(void)
542 {
543 	after_paging_init = 1;
544 }
545 
__early_set_fixmap(enum fixed_addresses idx,unsigned long phys,pgprot_t flags)546 static void __init __early_set_fixmap(enum fixed_addresses idx,
547 				   unsigned long phys, pgprot_t flags)
548 {
549 	unsigned long addr = __fix_to_virt(idx);
550 	pte_t *pte;
551 
552 	if (idx >= __end_of_fixed_addresses) {
553 		BUG();
554 		return;
555 	}
556 	pte = early_ioremap_pte(addr);
557 
558 	if (pgprot_val(flags))
559 		set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
560 	else
561 		pte_clear(&init_mm, addr, pte);
562 	__flush_tlb_one(addr);
563 }
564 
early_set_fixmap(enum fixed_addresses idx,unsigned long phys,pgprot_t prot)565 static inline void __init early_set_fixmap(enum fixed_addresses idx,
566 					   unsigned long phys, pgprot_t prot)
567 {
568 	if (after_paging_init)
569 		__set_fixmap(idx, phys, prot);
570 	else
571 		__early_set_fixmap(idx, phys, prot);
572 }
573 
early_clear_fixmap(enum fixed_addresses idx)574 static inline void __init early_clear_fixmap(enum fixed_addresses idx)
575 {
576 	if (after_paging_init)
577 		clear_fixmap(idx);
578 	else
579 		__early_set_fixmap(idx, 0, __pgprot(0));
580 }
581 
582 static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata;
583 static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;
check_early_ioremap_leak(void)584 static int __init check_early_ioremap_leak(void)
585 {
586 	int count = 0;
587 	int i;
588 
589 	for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
590 		if (prev_map[i])
591 			count++;
592 
593 	if (!count)
594 		return 0;
595 	WARN(1, KERN_WARNING
596 	       "Debug warning: early ioremap leak of %d areas detected.\n",
597 		count);
598 	printk(KERN_WARNING
599 		"please boot with early_ioremap_debug and report the dmesg.\n");
600 
601 	return 1;
602 }
603 late_initcall(check_early_ioremap_leak);
604 
__early_ioremap(unsigned long phys_addr,unsigned long size,pgprot_t prot)605 static void __init __iomem *__early_ioremap(unsigned long phys_addr, unsigned long size, pgprot_t prot)
606 {
607 	unsigned long offset, last_addr;
608 	unsigned int nrpages;
609 	enum fixed_addresses idx0, idx;
610 	int i, slot;
611 
612 	WARN_ON(system_state != SYSTEM_BOOTING);
613 
614 	slot = -1;
615 	for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
616 		if (!prev_map[i]) {
617 			slot = i;
618 			break;
619 		}
620 	}
621 
622 	if (slot < 0) {
623 		printk(KERN_INFO "early_iomap(%08lx, %08lx) not found slot\n",
624 			 phys_addr, size);
625 		WARN_ON(1);
626 		return NULL;
627 	}
628 
629 	if (early_ioremap_debug) {
630 		printk(KERN_INFO "early_ioremap(%08lx, %08lx) [%d] => ",
631 		       phys_addr, size, slot);
632 		dump_stack();
633 	}
634 
635 	/* Don't allow wraparound or zero size */
636 	last_addr = phys_addr + size - 1;
637 	if (!size || last_addr < phys_addr) {
638 		WARN_ON(1);
639 		return NULL;
640 	}
641 
642 	prev_size[slot] = size;
643 	/*
644 	 * Mappings have to be page-aligned
645 	 */
646 	offset = phys_addr & ~PAGE_MASK;
647 	phys_addr &= PAGE_MASK;
648 	size = PAGE_ALIGN(last_addr + 1) - phys_addr;
649 
650 	/*
651 	 * Mappings have to fit in the FIX_BTMAP area.
652 	 */
653 	nrpages = size >> PAGE_SHIFT;
654 	if (nrpages > NR_FIX_BTMAPS) {
655 		WARN_ON(1);
656 		return NULL;
657 	}
658 
659 	/*
660 	 * Ok, go for it..
661 	 */
662 	idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
663 	idx = idx0;
664 	while (nrpages > 0) {
665 		early_set_fixmap(idx, phys_addr, prot);
666 		phys_addr += PAGE_SIZE;
667 		--idx;
668 		--nrpages;
669 	}
670 	if (early_ioremap_debug)
671 		printk(KERN_CONT "%08lx + %08lx\n", offset, fix_to_virt(idx0));
672 
673 	prev_map[slot] = (void __iomem *)(offset + fix_to_virt(idx0));
674 	return prev_map[slot];
675 }
676 
677 /* Remap an IO device */
early_ioremap(unsigned long phys_addr,unsigned long size)678 void __init __iomem *early_ioremap(unsigned long phys_addr, unsigned long size)
679 {
680 	return __early_ioremap(phys_addr, size, PAGE_KERNEL_IO);
681 }
682 
683 /* Remap memory */
early_memremap(unsigned long phys_addr,unsigned long size)684 void __init __iomem *early_memremap(unsigned long phys_addr, unsigned long size)
685 {
686 	return __early_ioremap(phys_addr, size, PAGE_KERNEL);
687 }
688 
early_iounmap(void __iomem * addr,unsigned long size)689 void __init early_iounmap(void __iomem *addr, unsigned long size)
690 {
691 	unsigned long virt_addr;
692 	unsigned long offset;
693 	unsigned int nrpages;
694 	enum fixed_addresses idx;
695 	int i, slot;
696 
697 	slot = -1;
698 	for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
699 		if (prev_map[i] == addr) {
700 			slot = i;
701 			break;
702 		}
703 	}
704 
705 	if (slot < 0) {
706 		printk(KERN_INFO "early_iounmap(%p, %08lx) not found slot\n",
707 			 addr, size);
708 		WARN_ON(1);
709 		return;
710 	}
711 
712 	if (prev_size[slot] != size) {
713 		printk(KERN_INFO "early_iounmap(%p, %08lx) [%d] size not consistent %08lx\n",
714 			 addr, size, slot, prev_size[slot]);
715 		WARN_ON(1);
716 		return;
717 	}
718 
719 	if (early_ioremap_debug) {
720 		printk(KERN_INFO "early_iounmap(%p, %08lx) [%d]\n", addr,
721 		       size, slot);
722 		dump_stack();
723 	}
724 
725 	virt_addr = (unsigned long)addr;
726 	if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)) {
727 		WARN_ON(1);
728 		return;
729 	}
730 	offset = virt_addr & ~PAGE_MASK;
731 	nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT;
732 
733 	idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
734 	while (nrpages > 0) {
735 		early_clear_fixmap(idx);
736 		--idx;
737 		--nrpages;
738 	}
739 	prev_map[slot] = NULL;
740 }
741 
__this_fixmap_does_not_exist(void)742 void __this_fixmap_does_not_exist(void)
743 {
744 	WARN_ON(1);
745 }
746