[linux-2.6-block.git] / arch / x86 / mm / ioremap_32.c

/*
 * arch/i386/mm/ioremap.c
 *
 * Re-map IO memory to kernel address space so that we can access it.
 * This is needed for high PCI addresses that aren't mapped in the
 * 640k-1MB IO memory area on PC's
 *
 * (C) Copyright 1995 1996 Linus Torvalds
 */

#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/io.h>
#include <asm/fixmap.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/pgtable.h>

#define ISA_START_ADDRESS	0xa0000
#define ISA_END_ADDRESS		0x100000

/*
 * Generic mapping function (not visible outside):
 */

/*
 * Remap an arbitrary physical address space into the kernel virtual
 * address space. Needed when the kernel wants to access high addresses
 * directly.
 *
 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
 * have to convert them into an offset in a page-aligned mapping, but the
 * caller shouldn't need to know that small detail.
 */
void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
{
	void __iomem * addr;
	struct vm_struct * area;
	unsigned long offset, last_addr;
	pgprot_t prot;

	/* Don't allow wraparound or zero size */
	last_addr = phys_addr + size - 1;
	if (!size || last_addr < phys_addr)
		return NULL;

	/*
	 * Don't remap the low PCI/ISA area, it's always mapped..
	 */
	if (phys_addr >= ISA_START_ADDRESS && last_addr < ISA_END_ADDRESS)
		return (void __iomem *) phys_to_virt(phys_addr);

	/*
	 * Don't allow anybody to remap normal RAM that we're using..
	 */
	if (phys_addr <= virt_to_phys(high_memory - 1)) {
		char *t_addr, *t_end;
		struct page *page;

		t_addr = __va(phys_addr);
		t_end = t_addr + (size - 1);
	   
		for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++)
			if(!PageReserved(page))
				return NULL;
	}

	prot = MAKE_GLOBAL(__PAGE_KERNEL | flags);

	/*
	 * Mappings have to be page-aligned
	 */
	offset = phys_addr & ~PAGE_MASK;
	phys_addr &= PAGE_MASK;
	size = PAGE_ALIGN(last_addr+1) - phys_addr;

	/*
	 * Ok, go for it..
	 */
	area = get_vm_area(size, VM_IOREMAP | (flags << 20));
	if (!area)
		return NULL;
	area->phys_addr = phys_addr;
	addr = (void __iomem *) area->addr;
	if (ioremap_page_range((unsigned long) addr,
			(unsigned long) addr + size, phys_addr, prot)) {
		vunmap((void __force *) addr);
		return NULL;
	}
	return (void __iomem *) (offset + (char __iomem *)addr);
}
EXPORT_SYMBOL(__ioremap);

/**
 * ioremap_nocache     -   map bus memory into CPU space
 * @offset:    bus address of the memory
 * @size:      size of the resource to map
 *
 * ioremap_nocache performs a platform specific sequence of operations to
 * make bus memory CPU accessible via the readb/readw/readl/writeb/
 * writew/writel functions and the other mmio helpers. The returned
 * address is not guaranteed to be usable directly as a virtual
 * address. 
 *
 * This version of ioremap ensures that the memory is marked uncachable
 * on the CPU as well as honouring existing caching rules from things like
 * the PCI bus. Note that there are other caches and buffers on many 
 * busses. In particular driver authors should read up on PCI writes
 *
 * It's useful if some control registers are in such an area and
 * write combining or read caching is not desirable:
 * 
 * Must be freed with iounmap.
 */

void __iomem *ioremap_nocache (unsigned long phys_addr, unsigned long size)
{
	unsigned long last_addr;
	void __iomem *p = __ioremap(phys_addr, size, _PAGE_PCD | _PAGE_PWT);
	if (!p) 
		return p; 

	/* Guaranteed to be > phys_addr, as per __ioremap() */
	last_addr = phys_addr + size - 1;

	if (last_addr < virt_to_phys(high_memory) - 1) {
		struct page *ppage = virt_to_page(__va(phys_addr));		
		unsigned long npages;

		phys_addr &= PAGE_MASK;

		/* This might overflow and become zero.. */
		last_addr = PAGE_ALIGN(last_addr);

		/* .. but that's ok, because modulo-2**n arithmetic will make
	 	* the page-aligned "last - first" come out right.
	 	*/
		npages = (last_addr - phys_addr) >> PAGE_SHIFT;

		if (change_page_attr(ppage, npages, PAGE_KERNEL_NOCACHE) < 0) { 
			iounmap(p); 
			p = NULL;
		}
		global_flush_tlb();
	}

	return p;					
}
EXPORT_SYMBOL(ioremap_nocache);

/**
 * iounmap - Free a IO remapping
 * @addr: virtual address from ioremap_*
 *
 * Caller must ensure there is only one unmapping for the same pointer.
 */
void iounmap(volatile void __iomem *addr)
{
	struct vm_struct *p, *o;

	if ((void __force *)addr <= high_memory)
		return;

	/*
	 * __ioremap special-cases the PCI/ISA range by not instantiating a
	 * vm_area and by simply returning an address into the kernel mapping
	 * of ISA space.   So handle that here.
	 */
	if (addr >= phys_to_virt(ISA_START_ADDRESS) &&
			addr < phys_to_virt(ISA_END_ADDRESS))
		return;

	addr = (volatile void __iomem *)(PAGE_MASK & (unsigned long __force)addr);

	/* Use the vm area unlocked, assuming the caller
	   ensures there isn't another iounmap for the same address
	   in parallel. Reuse of the virtual address is prevented by
	   leaving it in the global lists until we're done with it.
	   cpa takes care of the direct mappings. */
	read_lock(&vmlist_lock);
	for (p = vmlist; p; p = p->next) {
		if (p->addr == addr)
			break;
	}
	read_unlock(&vmlist_lock);

	if (!p) {
		printk("iounmap: bad address %p\n", addr);
		dump_stack();
		return;
	}

	/* Reset the direct mapping. Can block */
	if ((p->flags >> 20) && p->phys_addr < virt_to_phys(high_memory) - 1) {
		change_page_attr(virt_to_page(__va(p->phys_addr)),
				 get_vm_area_size(p) >> PAGE_SHIFT,
				 PAGE_KERNEL);
		global_flush_tlb();
	} 

	/* Finally remove it */
	o = remove_vm_area((void *)addr);
	BUG_ON(p != o || o == NULL);
	kfree(p); 
}
EXPORT_SYMBOL(iounmap);


int __initdata early_ioremap_debug;

static int __init early_ioremap_debug_setup(char *str)
{
	early_ioremap_debug = 1;

	return 0;
}
early_param("early_ioremap_debug", early_ioremap_debug_setup);

static __initdata int after_paging_init;
static __initdata unsigned long bm_pte[1024]
				__attribute__((aligned(PAGE_SIZE)));

static inline unsigned long * __init early_ioremap_pgd(unsigned long addr)
{
	return (unsigned long *)swapper_pg_dir + ((addr >> 22) & 1023);
}

static inline unsigned long * __init early_ioremap_pte(unsigned long addr)
{
	return bm_pte + ((addr >> PAGE_SHIFT) & 1023);
}

void __init early_ioremap_init(void)
{
	unsigned long *pgd;

	if (early_ioremap_debug)
		printk("early_ioremap_init()\n");

	pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
	*pgd = __pa(bm_pte) | _PAGE_TABLE;
	memset(bm_pte, 0, sizeof(bm_pte));
	/*
	 * The boot-ioremap range spans multiple pgds, for which
	 * we are not prepared:
	 */
	if (pgd != early_ioremap_pgd(fix_to_virt(FIX_BTMAP_END))) {
		WARN_ON(1);
		printk("pgd %p != %p\n",
			pgd, early_ioremap_pgd(fix_to_virt(FIX_BTMAP_END)));
		printk("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
			fix_to_virt(FIX_BTMAP_BEGIN));
		printk("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
			fix_to_virt(FIX_BTMAP_END));

		printk("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
		printk("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
	}
}

void __init early_ioremap_clear(void)
{
	unsigned long *pgd;

	if (early_ioremap_debug)
		printk("early_ioremap_clear()\n");

	pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
	*pgd = 0;
	__flush_tlb_all();
}

void __init early_ioremap_reset(void)
{
	enum fixed_addresses idx;
	unsigned long *pte, phys, addr;

	after_paging_init = 1;
	for (idx = FIX_BTMAP_BEGIN; idx >= FIX_BTMAP_END; idx--) {
		addr = fix_to_virt(idx);
		pte = early_ioremap_pte(addr);
		if (!*pte & _PAGE_PRESENT) {
			phys = *pte & PAGE_MASK;
			set_fixmap(idx, phys);
		}
	}
}

static void __init __early_set_fixmap(enum fixed_addresses idx,
				   unsigned long phys, pgprot_t flags)
{
	unsigned long *pte, addr = __fix_to_virt(idx);

	if (idx >= __end_of_fixed_addresses) {
		BUG();
		return;
	}
	pte = early_ioremap_pte(addr);
	if (pgprot_val(flags))
		*pte = (phys & PAGE_MASK) | pgprot_val(flags);
	else
		*pte = 0;
	__flush_tlb_one(addr);
}

static inline void __init early_set_fixmap(enum fixed_addresses idx,
					unsigned long phys)
{
	if (after_paging_init)
		set_fixmap(idx, phys);
	else
		__early_set_fixmap(idx, phys, PAGE_KERNEL);
}

static inline void __init early_clear_fixmap(enum fixed_addresses idx)
{
	if (after_paging_init)
		clear_fixmap(idx);
	else
		__early_set_fixmap(idx, 0, __pgprot(0));
}


int __initdata early_ioremap_nested;

static int __init check_early_ioremap_leak(void)
{
	if (!early_ioremap_nested)
		return 0;

	printk(KERN_WARNING
		"Debug warning: early ioremap leak of %d areas detected.\n",
			early_ioremap_nested);
	printk(KERN_WARNING
		"please boot with early_ioremap_debug and report the dmesg.\n");
	WARN_ON(1);

	return 1;
}
late_initcall(check_early_ioremap_leak);

void __init *early_ioremap(unsigned long phys_addr, unsigned long size)
{
	unsigned long offset, last_addr;
	unsigned int nrpages, nesting;
	enum fixed_addresses idx0, idx;

	WARN_ON(system_state != SYSTEM_BOOTING);

	nesting = early_ioremap_nested;
	if (early_ioremap_debug) {
		printk("early_ioremap(%08lx, %08lx) [%d] => ",
				phys_addr, size, nesting);
		dump_stack();
	}

	/* Don't allow wraparound or zero size */
	last_addr = phys_addr + size - 1;
	if (!size || last_addr < phys_addr) {
		WARN_ON(1);
		return NULL;
	}

	if (nesting >= FIX_BTMAPS_NESTING) {
		WARN_ON(1);
		return NULL;
	}
	early_ioremap_nested++;
	/*
	 * Mappings have to be page-aligned
	 */
	offset = phys_addr & ~PAGE_MASK;
	phys_addr &= PAGE_MASK;
	size = PAGE_ALIGN(last_addr) - phys_addr;

	/*
	 * Mappings have to fit in the FIX_BTMAP area.
	 */
	nrpages = size >> PAGE_SHIFT;
	if (nrpages > NR_FIX_BTMAPS) {
		WARN_ON(1);
		return NULL;
	}

	/*
	 * Ok, go for it..
	 */
	idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
	idx = idx0;
	while (nrpages > 0) {
		early_set_fixmap(idx, phys_addr);
		phys_addr += PAGE_SIZE;
		--idx;
		--nrpages;
	}
	if (early_ioremap_debug)
		printk(KERN_CONT "%08lx + %08lx\n", offset, fix_to_virt(idx0));

	return (void*) (offset + fix_to_virt(idx0));
}

void __init early_iounmap(void *addr, unsigned long size)
{
	unsigned long virt_addr;
	unsigned long offset;
	unsigned int nrpages;
	enum fixed_addresses idx;
	unsigned int nesting;

	nesting = --early_ioremap_nested;
	WARN_ON(nesting < 0);

	if (early_ioremap_debug) {
		printk("early_iounmap(%p, %08lx) [%d]\n", addr, size, nesting);
		dump_stack();
	}

	virt_addr = (unsigned long)addr;
	if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)) {
		WARN_ON(1);
		return;
	}
	offset = virt_addr & ~PAGE_MASK;
	nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT;

	idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
	while (nrpages > 0) {
		early_clear_fixmap(idx);
		--idx;
		--nrpages;
	}
}

void __this_fixmap_does_not_exist(void)
{
	WARN_ON(1);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* arch/i386/mm/ioremap.c
	3	*
	4	* Re-map IO memory to kernel address space so that we can access it.
	5	* This is needed for high PCI addresses that aren't mapped in the
	6	* 640k-1MB IO memory area on PC's
	7	*
	8	* (C) Copyright 1995 1996 Linus Torvalds
	9	*/
	10
	11	#include <linux/vmalloc.h>
	12	#include <linux/init.h>
	13	#include <linux/slab.h>
129f6946	14	#include <linux/module.h>
a148ecfd	15	#include <linux/io.h>
1da177e4 LT	16	#include <asm/fixmap.h>
	17	#include <asm/cacheflush.h>
	18	#include <asm/tlbflush.h>
	19	#include <asm/pgtable.h>
	20
	21	#define ISA_START_ADDRESS 0xa0000
	22	#define ISA_END_ADDRESS 0x100000
	23
1da177e4 LT	24	/*
	25	* Generic mapping function (not visible outside):
	26	*/
	27
	28	/*
	29	* Remap an arbitrary physical address space into the kernel virtual
	30	* address space. Needed when the kernel wants to access high addresses
	31	* directly.
	32	*
	33	* NOTE! We need to allow non-page-aligned mappings too: we will obviously
	34	* have to convert them into an offset in a page-aligned mapping, but the
	35	* caller shouldn't need to know that small detail.
	36	*/
	37	void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
	38	{
	39	void __iomem * addr;
	40	struct vm_struct * area;
	41	unsigned long offset, last_addr;
a148ecfd	42	pgprot_t prot;
1da177e4 LT	43
	44	/* Don't allow wraparound or zero size */
	45	last_addr = phys_addr + size - 1;
	46	if (!size \|\| last_addr < phys_addr)
	47	return NULL;
	48
	49	/*
	50	* Don't remap the low PCI/ISA area, it's always mapped..
	51	*/
	52	if (phys_addr >= ISA_START_ADDRESS && last_addr < ISA_END_ADDRESS)
	53	return (void __iomem *) phys_to_virt(phys_addr);
	54
	55	/*
	56	* Don't allow anybody to remap normal RAM that we're using..
	57	*/
	58	if (phys_addr <= virt_to_phys(high_memory - 1)) {
	59	char t_addr, t_end;
	60	struct page *page;
	61
	62	t_addr = __va(phys_addr);
	63	t_end = t_addr + (size - 1);
	64
	65	for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++)
	66	if(!PageReserved(page))
	67	return NULL;
	68	}
	69
a4034349	70	prot = MAKE_GLOBAL(__PAGE_KERNEL \| flags);
a148ecfd	71
1da177e4 LT	72	/*
	73	* Mappings have to be page-aligned
	74	*/
	75	offset = phys_addr & ~PAGE_MASK;
	76	phys_addr &= PAGE_MASK;
	77	size = PAGE_ALIGN(last_addr+1) - phys_addr;
	78
	79	/*
	80	* Ok, go for it..
	81	*/
	82	area = get_vm_area(size, VM_IOREMAP \| (flags << 20));
	83	if (!area)
	84	return NULL;
	85	area->phys_addr = phys_addr;
	86	addr = (void __iomem *) area->addr;
	87	if (ioremap_page_range((unsigned long) addr,
a148ecfd	88	(unsigned long) addr + size, phys_addr, prot)) {
1da177e4 LT	89	vunmap((void __force *) addr);
	90	return NULL;
	91	}
	92	return (void __iomem ) (offset + (char __iomem )addr);
	93	}
129f6946	94	EXPORT_SYMBOL(__ioremap);
1da177e4 LT	95
	96	/**
	97	* ioremap_nocache - map bus memory into CPU space
	98	* @offset: bus address of the memory
	99	* @size: size of the resource to map
	100	*
	101	* ioremap_nocache performs a platform specific sequence of operations to
	102	* make bus memory CPU accessible via the readb/readw/readl/writeb/
	103	* writew/writel functions and the other mmio helpers. The returned
	104	* address is not guaranteed to be usable directly as a virtual
	105	* address.
	106	*
	107	* This version of ioremap ensures that the memory is marked uncachable
	108	* on the CPU as well as honouring existing caching rules from things like
	109	* the PCI bus. Note that there are other caches and buffers on many
	110	* busses. In particular driver authors should read up on PCI writes
	111	*
	112	* It's useful if some control registers are in such an area and
	113	* write combining or read caching is not desirable:
	114	*
	115	* Must be freed with iounmap.
	116	*/
	117
	118	void __iomem *ioremap_nocache (unsigned long phys_addr, unsigned long size)
	119	{
	120	unsigned long last_addr;
4138cc34	121	void __iomem *p = __ioremap(phys_addr, size, _PAGE_PCD \| _PAGE_PWT);
1da177e4 LT	122	if (!p)
	123	return p;
	124
	125	/* Guaranteed to be > phys_addr, as per __ioremap() */
	126	last_addr = phys_addr + size - 1;
	127
	128	if (last_addr < virt_to_phys(high_memory) - 1) {
	129	struct page *ppage = virt_to_page(__va(phys_addr));
	130	unsigned long npages;
	131
	132	phys_addr &= PAGE_MASK;
	133
	134	/* This might overflow and become zero.. */
	135	last_addr = PAGE_ALIGN(last_addr);
	136
	137	/* .. but that's ok, because modulo-2**n arithmetic will make
	138	* the page-aligned "last - first" come out right.
	139	*/
	140	npages = (last_addr - phys_addr) >> PAGE_SHIFT;
	141
	142	if (change_page_attr(ppage, npages, PAGE_KERNEL_NOCACHE) < 0) {
	143	iounmap(p);
	144	p = NULL;
	145	}
	146	global_flush_tlb();
	147	}
	148
	149	return p;
	150	}
129f6946	151	EXPORT_SYMBOL(ioremap_nocache);
1da177e4	152
bf5421c3 AK	153	/**
	154	* iounmap - Free a IO remapping
	155	* @addr: virtual address from ioremap_*
	156	*
	157	* Caller must ensure there is only one unmapping for the same pointer.
	158	*/
1da177e4 LT	159	void iounmap(volatile void __iomem *addr)
1da177e4 LT	160	{
bf5421c3	161	struct vm_struct p, o;
c23a4e96 AM	162
c23a4e96 AM	163	if ((void __force *)addr <= high_memory)
1da177e4 LT	164	return;
	165
	166	/*
	167	* __ioremap special-cases the PCI/ISA range by not instantiating a
	168	* vm_area and by simply returning an address into the kernel mapping
	169	* of ISA space. So handle that here.
	170	*/
	171	if (addr >= phys_to_virt(ISA_START_ADDRESS) &&
	172	addr < phys_to_virt(ISA_END_ADDRESS))
	173	return;
	174
b16b88e5	175	addr = (volatile void __iomem *)(PAGE_MASK & (unsigned long __force)addr);
bf5421c3 AK	176
	177	/* Use the vm area unlocked, assuming the caller
	178	ensures there isn't another iounmap for the same address
	179	in parallel. Reuse of the virtual address is prevented by
	180	leaving it in the global lists until we're done with it.
	181	cpa takes care of the direct mappings. */
	182	read_lock(&vmlist_lock);
	183	for (p = vmlist; p; p = p->next) {
	184	if (p->addr == addr)
	185	break;
	186	}
	187	read_unlock(&vmlist_lock);
	188
	189	if (!p) {
	190	printk("iounmap: bad address %p\n", addr);
c23a4e96	191	dump_stack();
bf5421c3	192	return;
1da177e4 LT	193	}
1da177e4 LT	194
bf5421c3	195	/* Reset the direct mapping. Can block */
1da177e4	196	if ((p->flags >> 20) && p->phys_addr < virt_to_phys(high_memory) - 1) {
1da177e4	197	change_page_attr(virt_to_page(__va(p->phys_addr)),
9585116b	198	get_vm_area_size(p) >> PAGE_SHIFT,
1da177e4 LT	199	PAGE_KERNEL);
	200	global_flush_tlb();
	201	}
bf5421c3 AK	202
	203	/* Finally remove it */
	204	o = remove_vm_area((void *)addr);
	205	BUG_ON(p != o \|\| o == NULL);
1da177e4 LT	206	kfree(p);
1da177e4 LT	207	}
129f6946	208	EXPORT_SYMBOL(iounmap);
1da177e4	209
d18d6d65 IM	210
	211	int __initdata early_ioremap_debug;
	212
	213	static int __init early_ioremap_debug_setup(char *str)
	214	{
	215	early_ioremap_debug = 1;
	216
793b24a2	217	return 0;
d18d6d65	218	}
793b24a2	219	early_param("early_ioremap_debug", early_ioremap_debug_setup);
d18d6d65	220
0947b2f3 HY	221	static __initdata int after_paging_init;
	222	static __initdata unsigned long bm_pte[1024]
	223	__attribute__((aligned(PAGE_SIZE)));
	224
beacfaac	225	static inline unsigned long * __init early_ioremap_pgd(unsigned long addr)
0947b2f3 HY	226	{
	227	return (unsigned long *)swapper_pg_dir + ((addr >> 22) & 1023);
	228	}
	229
beacfaac	230	static inline unsigned long * __init early_ioremap_pte(unsigned long addr)
0947b2f3 HY	231	{
	232	return bm_pte + ((addr >> PAGE_SHIFT) & 1023);
	233	}
	234
beacfaac	235	void __init early_ioremap_init(void)
0947b2f3 HY	236	{
	237	unsigned long *pgd;
	238
d18d6d65 IM	239	if (early_ioremap_debug)
	240	printk("early_ioremap_init()\n");
	241
beacfaac	242	pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
0947b2f3 HY	243	*pgd = __pa(bm_pte) \| _PAGE_TABLE;
0947b2f3 HY	244	memset(bm_pte, 0, sizeof(bm_pte));
0e3a9549 IM	245	/*
	246	* The boot-ioremap range spans multiple pgds, for which
	247	* we are not prepared:
	248	*/
	249	if (pgd != early_ioremap_pgd(fix_to_virt(FIX_BTMAP_END))) {
	250	WARN_ON(1);
	251	printk("pgd %p != %p\n",
	252	pgd, early_ioremap_pgd(fix_to_virt(FIX_BTMAP_END)));
	253	printk("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
	254	fix_to_virt(FIX_BTMAP_BEGIN));
	255	printk("fix_to_virt(FIX_BTMAP_END): %08lx\n",
	256	fix_to_virt(FIX_BTMAP_END));
	257
	258	printk("FIX_BTMAP_END: %d\n", FIX_BTMAP_END);
	259	printk("FIX_BTMAP_BEGIN: %d\n", FIX_BTMAP_BEGIN);
	260	}
0947b2f3 HY	261	}
0947b2f3 HY	262
beacfaac	263	void __init early_ioremap_clear(void)
0947b2f3 HY	264	{
	265	unsigned long *pgd;
	266
d18d6d65 IM	267	if (early_ioremap_debug)
	268	printk("early_ioremap_clear()\n");
	269
beacfaac	270	pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
0947b2f3 HY	271	*pgd = 0;
	272	__flush_tlb_all();
	273	}
	274
beacfaac	275	void __init early_ioremap_reset(void)
0947b2f3 HY	276	{
	277	enum fixed_addresses idx;
	278	unsigned long *pte, phys, addr;
	279
	280	after_paging_init = 1;
64a8f852	281	for (idx = FIX_BTMAP_BEGIN; idx >= FIX_BTMAP_END; idx--) {
0947b2f3	282	addr = fix_to_virt(idx);
beacfaac	283	pte = early_ioremap_pte(addr);
0947b2f3 HY	284	if (!*pte & _PAGE_PRESENT) {
	285	phys = *pte & PAGE_MASK;
	286	set_fixmap(idx, phys);
	287	}
	288	}
	289	}
	290
beacfaac	291	static void __init __early_set_fixmap(enum fixed_addresses idx,
0947b2f3 HY	292	unsigned long phys, pgprot_t flags)
	293	{
	294	unsigned long *pte, addr = __fix_to_virt(idx);
	295
	296	if (idx >= __end_of_fixed_addresses) {
	297	BUG();
	298	return;
	299	}
beacfaac	300	pte = early_ioremap_pte(addr);
0947b2f3 HY	301	if (pgprot_val(flags))
	302	*pte = (phys & PAGE_MASK) \| pgprot_val(flags);
	303	else
	304	*pte = 0;
	305	__flush_tlb_one(addr);
	306	}
	307
beacfaac	308	static inline void __init early_set_fixmap(enum fixed_addresses idx,
0947b2f3 HY	309	unsigned long phys)
	310	{
	311	if (after_paging_init)
	312	set_fixmap(idx, phys);
	313	else
beacfaac	314	__early_set_fixmap(idx, phys, PAGE_KERNEL);
0947b2f3 HY	315	}
0947b2f3 HY	316
beacfaac	317	static inline void __init early_clear_fixmap(enum fixed_addresses idx)
0947b2f3 HY	318	{
	319	if (after_paging_init)
	320	clear_fixmap(idx);
	321	else
beacfaac	322	__early_set_fixmap(idx, 0, __pgprot(0));
0947b2f3 HY	323	}
0947b2f3 HY	324
1b42f516 IM	325
	326	int __initdata early_ioremap_nested;
	327
d690b2af IM	328	static int __init check_early_ioremap_leak(void)
	329	{
	330	if (!early_ioremap_nested)
	331	return 0;
	332
	333	printk(KERN_WARNING
	334	"Debug warning: early ioremap leak of %d areas detected.\n",
	335	early_ioremap_nested);
	336	printk(KERN_WARNING
	337	"please boot with early_ioremap_debug and report the dmesg.\n");
	338	WARN_ON(1);
	339
	340	return 1;
	341	}
	342	late_initcall(check_early_ioremap_leak);
	343
beacfaac	344	void __init *early_ioremap(unsigned long phys_addr, unsigned long size)
1da177e4 LT	345	{
1da177e4 LT	346	unsigned long offset, last_addr;
1b42f516 IM	347	unsigned int nrpages, nesting;
	348	enum fixed_addresses idx0, idx;
	349
	350	WARN_ON(system_state != SYSTEM_BOOTING);
	351
	352	nesting = early_ioremap_nested;
d18d6d65 IM	353	if (early_ioremap_debug) {
	354	printk("early_ioremap(%08lx, %08lx) [%d] => ",
	355	phys_addr, size, nesting);
	356	dump_stack();
	357	}
1da177e4 LT	358
	359	/* Don't allow wraparound or zero size */
	360	last_addr = phys_addr + size - 1;
bd796ed0 IM	361	if (!size \|\| last_addr < phys_addr) {
bd796ed0 IM	362	WARN_ON(1);
1da177e4	363	return NULL;
bd796ed0	364	}
1da177e4	365
bd796ed0 IM	366	if (nesting >= FIX_BTMAPS_NESTING) {
bd796ed0 IM	367	WARN_ON(1);
1b42f516	368	return NULL;
bd796ed0	369	}
1b42f516	370	early_ioremap_nested++;
1da177e4 LT	371	/*
	372	* Mappings have to be page-aligned
	373	*/
	374	offset = phys_addr & ~PAGE_MASK;
	375	phys_addr &= PAGE_MASK;
	376	size = PAGE_ALIGN(last_addr) - phys_addr;
	377
	378	/*
	379	* Mappings have to fit in the FIX_BTMAP area.
	380	*/
	381	nrpages = size >> PAGE_SHIFT;
bd796ed0 IM	382	if (nrpages > NR_FIX_BTMAPS) {
bd796ed0 IM	383	WARN_ON(1);
1da177e4	384	return NULL;
bd796ed0	385	}
1da177e4 LT	386
	387	/*
	388	* Ok, go for it..
	389	*/
1b42f516 IM	390	idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
1b42f516 IM	391	idx = idx0;
1da177e4	392	while (nrpages > 0) {
beacfaac	393	early_set_fixmap(idx, phys_addr);
1da177e4 LT	394	phys_addr += PAGE_SIZE;
	395	--idx;
	396	--nrpages;
	397	}
d18d6d65 IM	398	if (early_ioremap_debug)
d18d6d65 IM	399	printk(KERN_CONT "%08lx + %08lx\n", offset, fix_to_virt(idx0));
1b42f516 IM	400
1b42f516 IM	401	return (void*) (offset + fix_to_virt(idx0));
1da177e4 LT	402	}
1da177e4 LT	403
beacfaac	404	void __init early_iounmap(void *addr, unsigned long size)
1da177e4 LT	405	{
	406	unsigned long virt_addr;
	407	unsigned long offset;
	408	unsigned int nrpages;
	409	enum fixed_addresses idx;
1b42f516 IM	410	unsigned int nesting;
	411
	412	nesting = --early_ioremap_nested;
bd796ed0	413	WARN_ON(nesting < 0);
1da177e4	414
d18d6d65 IM	415	if (early_ioremap_debug) {
	416	printk("early_iounmap(%p, %08lx) [%d]\n", addr, size, nesting);
	417	dump_stack();
	418	}
	419
1da177e4	420	virt_addr = (unsigned long)addr;
bd796ed0 IM	421	if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)) {
bd796ed0 IM	422	WARN_ON(1);
1da177e4	423	return;
bd796ed0	424	}
1da177e4 LT	425	offset = virt_addr & ~PAGE_MASK;
	426	nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT;
	427
1b42f516	428	idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
1da177e4	429	while (nrpages > 0) {
beacfaac	430	early_clear_fixmap(idx);
1da177e4 LT	431	--idx;
	432	--nrpages;
	433	}
	434	}
1b42f516 IM	435
	436	void __this_fixmap_does_not_exist(void)
	437	{
	438	WARN_ON(1);
	439	}