[mirror_ubuntu-jammy-kernel.git] / arch / x86 / 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/bootmem.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>

#include <asm/cacheflush.h>
#include <asm/e820.h>
#include <asm/fixmap.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/pgalloc.h>

enum ioremap_mode {
	IOR_MODE_UNCACHED,
	IOR_MODE_CACHED,
};

#ifdef CONFIG_X86_64

unsigned long __phys_addr(unsigned long x)
{
	if (x >= __START_KERNEL_map)
		return x - __START_KERNEL_map + phys_base;
	return x - PAGE_OFFSET;
}
EXPORT_SYMBOL(__phys_addr);

#endif

int page_is_ram(unsigned long pagenr)
{
	unsigned long addr, end;
	int i;

	for (i = 0; i < e820.nr_map; i++) {
		/*
		 * Not usable memory:
		 */
		if (e820.map[i].type != E820_RAM)
			continue;
		addr = (e820.map[i].addr + PAGE_SIZE-1) >> PAGE_SHIFT;
		end = (e820.map[i].addr + e820.map[i].size) >> PAGE_SHIFT;

		/*
		 * Sanity check: Some BIOSen report areas as RAM that
		 * are not. Notably the 640->1Mb area, which is the
		 * PCI BIOS area.
		 */
		if (addr >= (BIOS_BEGIN >> PAGE_SHIFT) &&
		    end < (BIOS_END >> PAGE_SHIFT))
			continue;

		if ((pagenr >= addr) && (pagenr < end))
			return 1;
	}
	return 0;
}

/*
 * Fix up the linear direct mapping of the kernel to avoid cache attribute
 * conflicts.
 */
static int ioremap_change_attr(unsigned long vaddr, unsigned long size,
			       enum ioremap_mode mode)
{
	unsigned long nrpages = size >> PAGE_SHIFT;
	int err;

	switch (mode) {
	case IOR_MODE_UNCACHED:
	default:
		err = set_memory_uc(vaddr, nrpages);
		break;
	case IOR_MODE_CACHED:
		err = set_memory_wb(vaddr, nrpages);
		break;
	}

	return err;
}

/*
 * 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.
 */
static void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
			       enum ioremap_mode mode)
{
	unsigned long pfn, offset, last_addr, vaddr;
	struct vm_struct *area;
	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 (__force void __iomem *)phys_to_virt(phys_addr);

	/*
	 * Don't allow anybody to remap normal RAM that we're using..
	 */
	for (pfn = phys_addr >> PAGE_SHIFT; pfn < max_pfn_mapped &&
	     (pfn << PAGE_SHIFT) < last_addr; pfn++) {
		if (page_is_ram(pfn) && pfn_valid(pfn) &&
		    !PageReserved(pfn_to_page(pfn)))
			return NULL;
	}

	switch (mode) {
	case IOR_MODE_UNCACHED:
	default:
		prot = PAGE_KERNEL_NOCACHE;
		break;
	case IOR_MODE_CACHED:
		prot = PAGE_KERNEL;
		break;
	}

	/*
	 * 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);
	if (!area)
		return NULL;
	area->phys_addr = phys_addr;
	vaddr = (unsigned long) area->addr;
	if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
		remove_vm_area((void *)(vaddr & PAGE_MASK));
		return NULL;
	}

	if (ioremap_change_attr(vaddr, size, mode) < 0) {
		vunmap(area->addr);
		return NULL;
	}

	return (void __iomem *) (vaddr + offset);
}

/**
 * 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)
{
	return __ioremap(phys_addr, size, IOR_MODE_UNCACHED);
}
EXPORT_SYMBOL(ioremap_nocache);

void __iomem *ioremap_cache(unsigned long phys_addr, unsigned long size)
{
	return __ioremap(phys_addr, size, IOR_MODE_CACHED);
}
EXPORT_SYMBOL(ioremap_cache);

/**
 * 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(KERN_ERR "iounmap: bad address %p\n", addr);
		dump_stack();
		return;
	}

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

#ifdef CONFIG_X86_32

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(KERN_INFO "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(KERN_WARNING "pgd %p != %p\n",
		       pgd, early_ioremap_pgd(fix_to_virt(FIX_BTMAP_END)));
		printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
		       fix_to_virt(FIX_BTMAP_BEGIN));
		printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END):   %08lx\n",
		       fix_to_virt(FIX_BTMAP_END));

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

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

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

	pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
	*pgd = 0;
	paravirt_release_pt(__pa(pgd) >> PAGE_SHIFT);
	__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(KERN_INFO "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(KERN_INFO "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);
}

#endif /* CONFIG_X86_32 */
Commit	Line	Data
1da177e4	1	/*
1da177e4 LT	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
e9332cac	9	#include <linux/bootmem.h>
1da177e4	10	#include <linux/init.h>
a148ecfd	11	#include <linux/io.h>
3cbd09e4 TG	12	#include <linux/module.h>
	13	#include <linux/slab.h>
	14	#include <linux/vmalloc.h>
	15
1da177e4	16	#include <asm/cacheflush.h>
3cbd09e4 TG	17	#include <asm/e820.h>
3cbd09e4 TG	18	#include <asm/fixmap.h>
1da177e4	19	#include <asm/pgtable.h>
3cbd09e4	20	#include <asm/tlbflush.h>
f6df72e7	21	#include <asm/pgalloc.h>
1da177e4	22
d806e5ee TG	23	enum ioremap_mode {
	24	IOR_MODE_UNCACHED,
	25	IOR_MODE_CACHED,
	26	};
	27
240d3a7c TG	28	#ifdef CONFIG_X86_64
	29
	30	unsigned long __phys_addr(unsigned long x)
	31	{
	32	if (x >= __START_KERNEL_map)
	33	return x - __START_KERNEL_map + phys_base;
	34	return x - PAGE_OFFSET;
	35	}
	36	EXPORT_SYMBOL(__phys_addr);
	37
	38	#endif
	39
5f5192b9 TG	40	int page_is_ram(unsigned long pagenr)
	41	{
	42	unsigned long addr, end;
	43	int i;
	44
	45	for (i = 0; i < e820.nr_map; i++) {
	46	/*
	47	* Not usable memory:
	48	*/
	49	if (e820.map[i].type != E820_RAM)
	50	continue;
5f5192b9 TG	51	addr = (e820.map[i].addr + PAGE_SIZE-1) >> PAGE_SHIFT;
5f5192b9 TG	52	end = (e820.map[i].addr + e820.map[i].size) >> PAGE_SHIFT;
950f9d95 TG	53
	54	/*
	55	* Sanity check: Some BIOSen report areas as RAM that
	56	* are not. Notably the 640->1Mb area, which is the
	57	* PCI BIOS area.
	58	*/
	59	if (addr >= (BIOS_BEGIN >> PAGE_SHIFT) &&
	60	end < (BIOS_END >> PAGE_SHIFT))
	61	continue;
	62
5f5192b9 TG	63	if ((pagenr >= addr) && (pagenr < end))
	64	return 1;
	65	}
	66	return 0;
	67	}
	68
e9332cac TG	69	/*
	70	* Fix up the linear direct mapping of the kernel to avoid cache attribute
	71	* conflicts.
	72	*/
75ab43bf	73	static int ioremap_change_attr(unsigned long vaddr, unsigned long size,
d806e5ee	74	enum ioremap_mode mode)
e9332cac	75	{
d806e5ee	76	unsigned long nrpages = size >> PAGE_SHIFT;
93809be8	77	int err;
e9332cac	78
d806e5ee TG	79	switch (mode) {
	80	case IOR_MODE_UNCACHED:
	81	default:
	82	err = set_memory_uc(vaddr, nrpages);
	83	break;
	84	case IOR_MODE_CACHED:
	85	err = set_memory_wb(vaddr, nrpages);
	86	break;
	87	}
e9332cac TG	88
	89	return err;
	90	}
	91
1da177e4 LT	92	/*
	93	* Remap an arbitrary physical address space into the kernel virtual
	94	* address space. Needed when the kernel wants to access high addresses
	95	* directly.
	96	*
	97	* NOTE! We need to allow non-page-aligned mappings too: we will obviously
	98	* have to convert them into an offset in a page-aligned mapping, but the
	99	* caller shouldn't need to know that small detail.
	100	*/
5f868152	101	static void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
d806e5ee	102	enum ioremap_mode mode)
1da177e4	103	{
e66aadbe	104	unsigned long pfn, offset, last_addr, vaddr;
91eebf40	105	struct vm_struct *area;
d806e5ee	106	pgprot_t prot;
1da177e4 LT	107
	108	/* Don't allow wraparound or zero size */
	109	last_addr = phys_addr + size - 1;
	110	if (!size \|\| last_addr < phys_addr)
	111	return NULL;
	112
	113	/*
	114	* Don't remap the low PCI/ISA area, it's always mapped..
	115	*/
	116	if (phys_addr >= ISA_START_ADDRESS && last_addr < ISA_END_ADDRESS)
4b40fcee	117	return (__force void __iomem *)phys_to_virt(phys_addr);
1da177e4 LT	118
	119	/*
	120	* Don't allow anybody to remap normal RAM that we're using..
	121	*/
38cb47ba IM	122	for (pfn = phys_addr >> PAGE_SHIFT; pfn < max_pfn_mapped &&
	123	(pfn << PAGE_SHIFT) < last_addr; pfn++) {
	124	if (page_is_ram(pfn) && pfn_valid(pfn) &&
	125	!PageReserved(pfn_to_page(pfn)))
266b9f87	126	return NULL;
1da177e4 LT	127	}
1da177e4 LT	128
d806e5ee TG	129	switch (mode) {
	130	case IOR_MODE_UNCACHED:
	131	default:
	132	prot = PAGE_KERNEL_NOCACHE;
	133	break;
	134	case IOR_MODE_CACHED:
	135	prot = PAGE_KERNEL;
	136	break;
	137	}
a148ecfd	138
1da177e4 LT	139	/*
	140	* Mappings have to be page-aligned
	141	*/
	142	offset = phys_addr & ~PAGE_MASK;
	143	phys_addr &= PAGE_MASK;
	144	size = PAGE_ALIGN(last_addr+1) - phys_addr;
	145
	146	/*
	147	* Ok, go for it..
	148	*/
74ff2857	149	area = get_vm_area(size, VM_IOREMAP);
1da177e4 LT	150	if (!area)
	151	return NULL;
	152	area->phys_addr = phys_addr;
e66aadbe TG	153	vaddr = (unsigned long) area->addr;
	154	if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
	155	remove_vm_area((void *)(vaddr & PAGE_MASK));
1da177e4 LT	156	return NULL;
1da177e4 LT	157	}
e9332cac	158
75ab43bf	159	if (ioremap_change_attr(vaddr, size, mode) < 0) {
e66aadbe	160	vunmap(area->addr);
e9332cac TG	161	return NULL;
	162	}
	163
e66aadbe	164	return (void __iomem *) (vaddr + offset);
1da177e4	165	}
1da177e4 LT	166
	167	/**
	168	* ioremap_nocache - map bus memory into CPU space
	169	* @offset: bus address of the memory
	170	* @size: size of the resource to map
	171	*
	172	* ioremap_nocache performs a platform specific sequence of operations to
	173	* make bus memory CPU accessible via the readb/readw/readl/writeb/
	174	* writew/writel functions and the other mmio helpers. The returned
	175	* address is not guaranteed to be usable directly as a virtual
91eebf40	176	* address.
1da177e4 LT	177	*
	178	* This version of ioremap ensures that the memory is marked uncachable
	179	* on the CPU as well as honouring existing caching rules from things like
91eebf40	180	* the PCI bus. Note that there are other caches and buffers on many
1da177e4 LT	181	* busses. In particular driver authors should read up on PCI writes
	182	*
	183	* It's useful if some control registers are in such an area and
	184	* write combining or read caching is not desirable:
91eebf40	185	*
1da177e4 LT	186	* Must be freed with iounmap.
1da177e4 LT	187	*/
91eebf40	188	void __iomem *ioremap_nocache(unsigned long phys_addr, unsigned long size)
1da177e4	189	{
d806e5ee	190	return __ioremap(phys_addr, size, IOR_MODE_UNCACHED);
1da177e4	191	}
129f6946	192	EXPORT_SYMBOL(ioremap_nocache);
1da177e4	193
5f868152 TG	194	void __iomem *ioremap_cache(unsigned long phys_addr, unsigned long size)
5f868152 TG	195	{
d806e5ee	196	return __ioremap(phys_addr, size, IOR_MODE_CACHED);
5f868152 TG	197	}
	198	EXPORT_SYMBOL(ioremap_cache);
	199
bf5421c3 AK	200	/**
	201	* iounmap - Free a IO remapping
	202	* @addr: virtual address from ioremap_*
	203	*
	204	* Caller must ensure there is only one unmapping for the same pointer.
	205	*/
1da177e4 LT	206	void iounmap(volatile void __iomem *addr)
1da177e4 LT	207	{
bf5421c3	208	struct vm_struct p, o;
c23a4e96 AM	209
c23a4e96 AM	210	if ((void __force *)addr <= high_memory)
1da177e4 LT	211	return;
	212
	213	/*
	214	* __ioremap special-cases the PCI/ISA range by not instantiating a
	215	* vm_area and by simply returning an address into the kernel mapping
	216	* of ISA space. So handle that here.
	217	*/
	218	if (addr >= phys_to_virt(ISA_START_ADDRESS) &&
91eebf40	219	addr < phys_to_virt(ISA_END_ADDRESS))
1da177e4 LT	220	return;
1da177e4 LT	221
91eebf40 TG	222	addr = (volatile void __iomem *)
91eebf40 TG	223	(PAGE_MASK & (unsigned long __force)addr);
bf5421c3 AK	224
	225	/* Use the vm area unlocked, assuming the caller
	226	ensures there isn't another iounmap for the same address
	227	in parallel. Reuse of the virtual address is prevented by
	228	leaving it in the global lists until we're done with it.
	229	cpa takes care of the direct mappings. */
	230	read_lock(&vmlist_lock);
	231	for (p = vmlist; p; p = p->next) {
	232	if (p->addr == addr)
	233	break;
	234	}
	235	read_unlock(&vmlist_lock);
	236
	237	if (!p) {
91eebf40	238	printk(KERN_ERR "iounmap: bad address %p\n", addr);
c23a4e96	239	dump_stack();
bf5421c3	240	return;
1da177e4 LT	241	}
1da177e4 LT	242
bf5421c3 AK	243	/* Finally remove it */
	244	o = remove_vm_area((void *)addr);
	245	BUG_ON(p != o \|\| o == NULL);
91eebf40	246	kfree(p);
1da177e4	247	}
129f6946	248	EXPORT_SYMBOL(iounmap);
1da177e4	249
240d3a7c	250	#ifdef CONFIG_X86_32
d18d6d65 IM	251
	252	int __initdata early_ioremap_debug;
	253
	254	static int __init early_ioremap_debug_setup(char *str)
	255	{
	256	early_ioremap_debug = 1;
	257
793b24a2	258	return 0;
d18d6d65	259	}
793b24a2	260	early_param("early_ioremap_debug", early_ioremap_debug_setup);
d18d6d65	261
0947b2f3 HY	262	static __initdata int after_paging_init;
	263	static __initdata unsigned long bm_pte[1024]
	264	__attribute__((aligned(PAGE_SIZE)));
	265
beacfaac	266	static inline unsigned long * __init early_ioremap_pgd(unsigned long addr)
0947b2f3 HY	267	{
	268	return (unsigned long *)swapper_pg_dir + ((addr >> 22) & 1023);
	269	}
	270
beacfaac	271	static inline unsigned long * __init early_ioremap_pte(unsigned long addr)
0947b2f3 HY	272	{
	273	return bm_pte + ((addr >> PAGE_SHIFT) & 1023);
	274	}
	275
beacfaac	276	void __init early_ioremap_init(void)
0947b2f3 HY	277	{
	278	unsigned long *pgd;
	279
d18d6d65	280	if (early_ioremap_debug)
adafdf6a	281	printk(KERN_INFO "early_ioremap_init()\n");
d18d6d65	282
beacfaac	283	pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
0947b2f3 HY	284	*pgd = __pa(bm_pte) \| _PAGE_TABLE;
0947b2f3 HY	285	memset(bm_pte, 0, sizeof(bm_pte));
0e3a9549 IM	286	/*
	287	* The boot-ioremap range spans multiple pgds, for which
	288	* we are not prepared:
	289	*/
	290	if (pgd != early_ioremap_pgd(fix_to_virt(FIX_BTMAP_END))) {
	291	WARN_ON(1);
91eebf40 TG	292	printk(KERN_WARNING "pgd %p != %p\n",
	293	pgd, early_ioremap_pgd(fix_to_virt(FIX_BTMAP_END)));
	294	printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
	295	fix_to_virt(FIX_BTMAP_BEGIN));
	296	printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END): %08lx\n",
	297	fix_to_virt(FIX_BTMAP_END));
	298
	299	printk(KERN_WARNING "FIX_BTMAP_END: %d\n", FIX_BTMAP_END);
	300	printk(KERN_WARNING "FIX_BTMAP_BEGIN: %d\n",
	301	FIX_BTMAP_BEGIN);
0e3a9549	302	}
0947b2f3 HY	303	}
0947b2f3 HY	304
beacfaac	305	void __init early_ioremap_clear(void)
0947b2f3 HY	306	{
	307	unsigned long *pgd;
	308
d18d6d65	309	if (early_ioremap_debug)
adafdf6a	310	printk(KERN_INFO "early_ioremap_clear()\n");
d18d6d65	311
beacfaac	312	pgd = early_ioremap_pgd(fix_to_virt(FIX_BTMAP_BEGIN));
0947b2f3	313	*pgd = 0;
f6df72e7	314	paravirt_release_pt(__pa(pgd) >> PAGE_SHIFT);
0947b2f3 HY	315	__flush_tlb_all();
	316	}
	317
beacfaac	318	void __init early_ioremap_reset(void)
0947b2f3 HY	319	{
	320	enum fixed_addresses idx;
	321	unsigned long *pte, phys, addr;
	322
	323	after_paging_init = 1;
64a8f852	324	for (idx = FIX_BTMAP_BEGIN; idx >= FIX_BTMAP_END; idx--) {
0947b2f3	325	addr = fix_to_virt(idx);
beacfaac	326	pte = early_ioremap_pte(addr);
1fd6a53d	327	if (*pte & _PAGE_PRESENT) {
0947b2f3 HY	328	phys = *pte & PAGE_MASK;
	329	set_fixmap(idx, phys);
	330	}
	331	}
	332	}
	333
beacfaac	334	static void __init __early_set_fixmap(enum fixed_addresses idx,
0947b2f3 HY	335	unsigned long phys, pgprot_t flags)
	336	{
	337	unsigned long *pte, addr = __fix_to_virt(idx);
	338
	339	if (idx >= __end_of_fixed_addresses) {
	340	BUG();
	341	return;
	342	}
beacfaac	343	pte = early_ioremap_pte(addr);
0947b2f3 HY	344	if (pgprot_val(flags))
	345	*pte = (phys & PAGE_MASK) \| pgprot_val(flags);
	346	else
	347	*pte = 0;
	348	__flush_tlb_one(addr);
	349	}
	350
beacfaac	351	static inline void __init early_set_fixmap(enum fixed_addresses idx,
0947b2f3 HY	352	unsigned long phys)
	353	{
	354	if (after_paging_init)
	355	set_fixmap(idx, phys);
	356	else
beacfaac	357	__early_set_fixmap(idx, phys, PAGE_KERNEL);
0947b2f3 HY	358	}
0947b2f3 HY	359
beacfaac	360	static inline void __init early_clear_fixmap(enum fixed_addresses idx)
0947b2f3 HY	361	{
	362	if (after_paging_init)
	363	clear_fixmap(idx);
	364	else
beacfaac	365	__early_set_fixmap(idx, 0, __pgprot(0));
0947b2f3 HY	366	}
0947b2f3 HY	367
1b42f516 IM	368
	369	int __initdata early_ioremap_nested;
	370
d690b2af IM	371	static int __init check_early_ioremap_leak(void)
	372	{
	373	if (!early_ioremap_nested)
	374	return 0;
	375
	376	printk(KERN_WARNING
91eebf40 TG	377	"Debug warning: early ioremap leak of %d areas detected.\n",
91eebf40 TG	378	early_ioremap_nested);
d690b2af	379	printk(KERN_WARNING
91eebf40	380	"please boot with early_ioremap_debug and report the dmesg.\n");
d690b2af IM	381	WARN_ON(1);
	382
	383	return 1;
	384	}
	385	late_initcall(check_early_ioremap_leak);
	386
beacfaac	387	void __init *early_ioremap(unsigned long phys_addr, unsigned long size)
1da177e4 LT	388	{
1da177e4 LT	389	unsigned long offset, last_addr;
1b42f516 IM	390	unsigned int nrpages, nesting;
	391	enum fixed_addresses idx0, idx;
	392
	393	WARN_ON(system_state != SYSTEM_BOOTING);
	394
	395	nesting = early_ioremap_nested;
d18d6d65	396	if (early_ioremap_debug) {
adafdf6a	397	printk(KERN_INFO "early_ioremap(%08lx, %08lx) [%d] => ",
91eebf40	398	phys_addr, size, nesting);
d18d6d65 IM	399	dump_stack();
d18d6d65 IM	400	}
1da177e4 LT	401
	402	/* Don't allow wraparound or zero size */
	403	last_addr = phys_addr + size - 1;
bd796ed0 IM	404	if (!size \|\| last_addr < phys_addr) {
bd796ed0 IM	405	WARN_ON(1);
1da177e4	406	return NULL;
bd796ed0	407	}
1da177e4	408
bd796ed0 IM	409	if (nesting >= FIX_BTMAPS_NESTING) {
bd796ed0 IM	410	WARN_ON(1);
1b42f516	411	return NULL;
bd796ed0	412	}
1b42f516	413	early_ioremap_nested++;
1da177e4 LT	414	/*
	415	* Mappings have to be page-aligned
	416	*/
	417	offset = phys_addr & ~PAGE_MASK;
	418	phys_addr &= PAGE_MASK;
	419	size = PAGE_ALIGN(last_addr) - phys_addr;
	420
	421	/*
	422	* Mappings have to fit in the FIX_BTMAP area.
	423	*/
	424	nrpages = size >> PAGE_SHIFT;
bd796ed0 IM	425	if (nrpages > NR_FIX_BTMAPS) {
bd796ed0 IM	426	WARN_ON(1);
1da177e4	427	return NULL;
bd796ed0	428	}
1da177e4 LT	429
	430	/*
	431	* Ok, go for it..
	432	*/
1b42f516 IM	433	idx0 = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
1b42f516 IM	434	idx = idx0;
1da177e4	435	while (nrpages > 0) {
beacfaac	436	early_set_fixmap(idx, phys_addr);
1da177e4 LT	437	phys_addr += PAGE_SIZE;
	438	--idx;
	439	--nrpages;
	440	}
d18d6d65 IM	441	if (early_ioremap_debug)
d18d6d65 IM	442	printk(KERN_CONT "%08lx + %08lx\n", offset, fix_to_virt(idx0));
1b42f516	443
91eebf40	444	return (void *) (offset + fix_to_virt(idx0));
1da177e4 LT	445	}
1da177e4 LT	446
beacfaac	447	void __init early_iounmap(void *addr, unsigned long size)
1da177e4 LT	448	{
	449	unsigned long virt_addr;
	450	unsigned long offset;
	451	unsigned int nrpages;
	452	enum fixed_addresses idx;
1b42f516 IM	453	unsigned int nesting;
	454
	455	nesting = --early_ioremap_nested;
bd796ed0	456	WARN_ON(nesting < 0);
1da177e4	457
d18d6d65	458	if (early_ioremap_debug) {
adafdf6a	459	printk(KERN_INFO "early_iounmap(%p, %08lx) [%d]\n", addr,
91eebf40	460	size, nesting);
d18d6d65 IM	461	dump_stack();
	462	}
	463
1da177e4	464	virt_addr = (unsigned long)addr;
bd796ed0 IM	465	if (virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)) {
bd796ed0 IM	466	WARN_ON(1);
1da177e4	467	return;
bd796ed0	468	}
1da177e4 LT	469	offset = virt_addr & ~PAGE_MASK;
	470	nrpages = PAGE_ALIGN(offset + size - 1) >> PAGE_SHIFT;
	471
1b42f516	472	idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*nesting;
1da177e4	473	while (nrpages > 0) {
beacfaac	474	early_clear_fixmap(idx);
1da177e4 LT	475	--idx;
	476	--nrpages;
	477	}
	478	}
1b42f516 IM	479
	480	void __this_fixmap_does_not_exist(void)
	481	{
	482	WARN_ON(1);
	483	}
240d3a7c TG	484
240d3a7c TG	485	#endif /* CONFIG_X86_32 */