[deliverable/linux.git] / arch / arm / mm / ioremap.c

/*
 *  linux/arch/arm/mm/ioremap.c
 *
 * Re-map IO memory to kernel address space so that we can access it.
 *
 * (C) Copyright 1995 1996 Linus Torvalds
 *
 * Hacked for ARM by Phil Blundell <philb@gnu.org>
 * Hacked to allow all architectures to build, and various cleanups
 * by Russell King
 *
 * This allows a driver to remap an arbitrary region of bus memory into
 * virtual space.  One should *only* use readl, writel, memcpy_toio and
 * so on with such remapped areas.
 *
 * Because the ARM only has a 32-bit address space we can't address the
 * whole of the (physical) PCI space at once.  PCI huge-mode addressing
 * allows us to circumvent this restriction by splitting PCI space into
 * two 2GB chunks and mapping only one at a time into processor memory.
 * We use MMU protection domains to trap any attempt to access the bank
 * that is not currently mapped.  (This isn't fully implemented yet.)
 */
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>

#include <asm/cacheflush.h>
#include <asm/io.h>
#include <asm/mmu_context.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include <asm/sizes.h>

/*
 * Used by ioremap() and iounmap() code to mark (super)section-mapped
 * I/O regions in vm_struct->flags field.
 */
#define VM_ARM_SECTION_MAPPING	0x80000000

static int remap_area_pte(pmd_t *pmd, unsigned long addr, unsigned long end,
			  unsigned long phys_addr, pgprot_t prot)
{
	pte_t *pte;

	pte = pte_alloc_kernel(pmd, addr);
	if (!pte)
		return -ENOMEM;

	do {
		if (!pte_none(*pte))
			goto bad;

		set_pte_ext(pte, pfn_pte(phys_addr >> PAGE_SHIFT, prot), 0);
		phys_addr += PAGE_SIZE;
	} while (pte++, addr += PAGE_SIZE, addr != end);
	return 0;

 bad:
	printk(KERN_CRIT "remap_area_pte: page already exists\n");
	BUG();
}

static inline int remap_area_pmd(pgd_t *pgd, unsigned long addr,
				 unsigned long end, unsigned long phys_addr,
				 pgprot_t prot)
{
	unsigned long next;
	pmd_t *pmd;
	int ret = 0;

	pmd = pmd_alloc(&init_mm, pgd, addr);
	if (!pmd)
		return -ENOMEM;

	do {
		next = pmd_addr_end(addr, end);
		ret = remap_area_pte(pmd, addr, next, phys_addr, prot);
		if (ret)
			return ret;
		phys_addr += next - addr;
	} while (pmd++, addr = next, addr != end);
	return ret;
}

static int remap_area_pages(unsigned long start, unsigned long pfn,
			    unsigned long size, unsigned long flags)
{
	unsigned long addr = start;
	unsigned long next, end = start + size;
	unsigned long phys_addr = __pfn_to_phys(pfn);
	pgprot_t prot = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
				 L_PTE_DIRTY | L_PTE_WRITE | flags);
	pgd_t *pgd;
	int err = 0;

	BUG_ON(addr >= end);
	pgd = pgd_offset_k(addr);
	do {
		next = pgd_addr_end(addr, end);
		err = remap_area_pmd(pgd, addr, next, phys_addr, prot);
		if (err)
			break;
		phys_addr += next - addr;
	} while (pgd++, addr = next, addr != end);

	return err;
}


void __check_kvm_seq(struct mm_struct *mm)
{
	unsigned int seq;

	do {
		seq = init_mm.context.kvm_seq;
		memcpy(pgd_offset(mm, VMALLOC_START),
		       pgd_offset_k(VMALLOC_START),
		       sizeof(pgd_t) * (pgd_index(VMALLOC_END) -
					pgd_index(VMALLOC_START)));
		mm->context.kvm_seq = seq;
	} while (seq != init_mm.context.kvm_seq);
}

#ifndef CONFIG_SMP
/*
 * Section support is unsafe on SMP - If you iounmap and ioremap a region,
 * the other CPUs will not see this change until their next context switch.
 * Meanwhile, (eg) if an interrupt comes in on one of those other CPUs
 * which requires the new ioremap'd region to be referenced, the CPU will
 * reference the _old_ region.
 *
 * Note that get_vm_area() allocates a guard 4K page, so we need to mask
 * the size back to 1MB aligned or we will overflow in the loop below.
 */
static void unmap_area_sections(unsigned long virt, unsigned long size)
{
	unsigned long addr = virt, end = virt + (size & ~SZ_1M);
	pgd_t *pgd;

	flush_cache_vunmap(addr, end);
	pgd = pgd_offset_k(addr);
	do {
		pmd_t pmd, *pmdp = pmd_offset(pgd, addr);

		pmd = *pmdp;
		if (!pmd_none(pmd)) {
			/*
			 * Clear the PMD from the page table, and
			 * increment the kvm sequence so others
			 * notice this change.
			 *
			 * Note: this is still racy on SMP machines.
			 */
			pmd_clear(pmdp);
			init_mm.context.kvm_seq++;

			/*
			 * Free the page table, if there was one.
			 */
			if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE)
				pte_free_kernel(pmd_page_vaddr(pmd));
		}

		addr += PGDIR_SIZE;
		pgd++;
	} while (addr < end);

	/*
	 * Ensure that the active_mm is up to date - we want to
	 * catch any use-after-iounmap cases.
	 */
	if (current->active_mm->context.kvm_seq != init_mm.context.kvm_seq)
		__check_kvm_seq(current->active_mm);

	flush_tlb_kernel_range(virt, end);
}

static int
remap_area_sections(unsigned long virt, unsigned long pfn,
		    unsigned long size, unsigned long flags)
{
	unsigned long prot, addr = virt, end = virt + size;
	pgd_t *pgd;

	/*
	 * Remove and free any PTE-based mapping, and
	 * sync the current kernel mapping.
	 */
	unmap_area_sections(virt, size);

	prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_DOMAIN(DOMAIN_IO) |
	       (flags & (L_PTE_CACHEABLE | L_PTE_BUFFERABLE));

	/*
	 * ARMv6 and above need XN set to prevent speculative prefetches
	 * hitting IO.
	 */
	if (cpu_architecture() >= CPU_ARCH_ARMv6)
		prot |= PMD_SECT_XN;

	pgd = pgd_offset_k(addr);
	do {
		pmd_t *pmd = pmd_offset(pgd, addr);

		pmd[0] = __pmd(__pfn_to_phys(pfn) | prot);
		pfn += SZ_1M >> PAGE_SHIFT;
		pmd[1] = __pmd(__pfn_to_phys(pfn) | prot);
		pfn += SZ_1M >> PAGE_SHIFT;
		flush_pmd_entry(pmd);

		addr += PGDIR_SIZE;
		pgd++;
	} while (addr < end);

	return 0;
}

static int
remap_area_supersections(unsigned long virt, unsigned long pfn,
			 unsigned long size, unsigned long flags)
{
	unsigned long prot, addr = virt, end = virt + size;
	pgd_t *pgd;

	/*
	 * Remove and free any PTE-based mapping, and
	 * sync the current kernel mapping.
	 */
	unmap_area_sections(virt, size);

	prot = PMD_TYPE_SECT | PMD_SECT_SUPER | PMD_SECT_AP_WRITE |
			PMD_DOMAIN(DOMAIN_IO) |
			(flags & (L_PTE_CACHEABLE | L_PTE_BUFFERABLE));

	/*
	 * ARMv6 and above need XN set to prevent speculative prefetches
	 * hitting IO.
	 */
	if (cpu_architecture() >= CPU_ARCH_ARMv6)
		prot |= PMD_SECT_XN;

	pgd = pgd_offset_k(virt);
	do {
		unsigned long super_pmd_val, i;

		super_pmd_val = __pfn_to_phys(pfn) | prot;
		super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20;

		for (i = 0; i < 8; i++) {
			pmd_t *pmd = pmd_offset(pgd, addr);

			pmd[0] = __pmd(super_pmd_val);
			pmd[1] = __pmd(super_pmd_val);
			flush_pmd_entry(pmd);

			addr += PGDIR_SIZE;
			pgd++;
		}

		pfn += SUPERSECTION_SIZE >> PAGE_SHIFT;
	} while (addr < end);

	return 0;
}
#endif


/*
 * 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.
 *
 * 'flags' are the extra L_PTE_ flags that you want to specify for this
 * mapping.  See include/asm-arm/proc-armv/pgtable.h for more information.
 */
void __iomem *
__ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
	      unsigned long flags)
{
	int err;
	unsigned long addr;
 	struct vm_struct * area;

	/*
	 * High mappings must be supersection aligned
	 */
	if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SUPERSECTION_MASK))
		return NULL;

 	area = get_vm_area(size, VM_IOREMAP);
 	if (!area)
 		return NULL;
 	addr = (unsigned long)area->addr;

#ifndef CONFIG_SMP
	if ((((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) ||
	       cpu_is_xsc3()) &&
	       !((__pfn_to_phys(pfn) | size | addr) & ~SUPERSECTION_MASK)) {
		area->flags |= VM_ARM_SECTION_MAPPING;
		err = remap_area_supersections(addr, pfn, size, flags);
	} else if (!((__pfn_to_phys(pfn) | size | addr) & ~PMD_MASK)) {
		area->flags |= VM_ARM_SECTION_MAPPING;
		err = remap_area_sections(addr, pfn, size, flags);
	} else
#endif
		err = remap_area_pages(addr, pfn, size, flags);

	if (err) {
 		vunmap((void *)addr);
 		return NULL;
 	}

	flush_cache_vmap(addr, addr + size);
	return (void __iomem *) (offset + addr);
}
EXPORT_SYMBOL(__ioremap_pfn);

void __iomem *
__ioremap(unsigned long phys_addr, size_t size, unsigned long flags)
{
	unsigned long last_addr;
 	unsigned long offset = phys_addr & ~PAGE_MASK;
 	unsigned long pfn = __phys_to_pfn(phys_addr);

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

	/*
 	 * Page align the mapping size
	 */
	size = PAGE_ALIGN(last_addr + 1) - phys_addr;

 	return __ioremap_pfn(pfn, offset, size, flags);
}
EXPORT_SYMBOL(__ioremap);

void __iounmap(volatile void __iomem *addr)
{
#ifndef CONFIG_SMP
	struct vm_struct **p, *tmp;
#endif
	unsigned int section_mapping = 0;

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

#ifndef CONFIG_SMP
	/*
	 * If this is a section based mapping we need to handle it
	 * specially as the VM subysystem does not know how to handle
	 * such a beast. We need the lock here b/c we need to clear
	 * all the mappings before the area can be reclaimed
	 * by someone else.
	 */
	write_lock(&vmlist_lock);
	for (p = &vmlist ; (tmp = *p) ; p = &tmp->next) {
		if((tmp->flags & VM_IOREMAP) && (tmp->addr == addr)) {
			if (tmp->flags & VM_ARM_SECTION_MAPPING) {
				*p = tmp->next;
				unmap_area_sections((unsigned long)tmp->addr,
						    tmp->size);
				kfree(tmp);
				section_mapping = 1;
			}
			break;
		}
	}
	write_unlock(&vmlist_lock);
#endif

	if (!section_mapping)
		vunmap((void __force *)addr);
}
EXPORT_SYMBOL(__iounmap);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/arm/mm/ioremap.c
	3	*
	4	* Re-map IO memory to kernel address space so that we can access it.
	5	*
	6	* (C) Copyright 1995 1996 Linus Torvalds
	7	*
	8	* Hacked for ARM by Phil Blundell <philb@gnu.org>
	9	* Hacked to allow all architectures to build, and various cleanups
	10	* by Russell King
	11	*
	12	* This allows a driver to remap an arbitrary region of bus memory into
	13	* virtual space. One should only use readl, writel, memcpy_toio and
	14	* so on with such remapped areas.
	15	*
	16	* Because the ARM only has a 32-bit address space we can't address the
	17	* whole of the (physical) PCI space at once. PCI huge-mode addressing
	18	* allows us to circumvent this restriction by splitting PCI space into
	19	* two 2GB chunks and mapping only one at a time into processor memory.
	20	* We use MMU protection domains to trap any attempt to access the bank
	21	* that is not currently mapped. (This isn't fully implemented yet.)
	22	*/
	23	#include <linux/module.h>
	24	#include <linux/errno.h>
	25	#include <linux/mm.h>
	26	#include <linux/vmalloc.h>
	27
	28	#include <asm/cacheflush.h>
	29	#include <asm/io.h>
ff0daca5 RK	30	#include <asm/mmu_context.h>
ff0daca5 RK	31	#include <asm/pgalloc.h>
1da177e4	32	#include <asm/tlbflush.h>
ff0daca5 RK	33	#include <asm/sizes.h>
	34
	35	/*
a069c896 LB	36	* Used by ioremap() and iounmap() code to mark (super)section-mapped
a069c896 LB	37	* I/O regions in vm_struct->flags field.
ff0daca5 RK	38	*/
ff0daca5 RK	39	#define VM_ARM_SECTION_MAPPING 0x80000000
1da177e4	40
da2c12a2 RK	41	static int remap_area_pte(pmd_t *pmd, unsigned long addr, unsigned long end,
da2c12a2 RK	42	unsigned long phys_addr, pgprot_t prot)
1da177e4	43	{
da2c12a2 RK	44	pte_t *pte;
	45
	46	pte = pte_alloc_kernel(pmd, addr);
	47	if (!pte)
	48	return -ENOMEM;
1da177e4	49
1da177e4 LT	50	do {
	51	if (!pte_none(*pte))
	52	goto bad;
	53
ad1ae2fe	54	set_pte_ext(pte, pfn_pte(phys_addr >> PAGE_SHIFT, prot), 0);
1da177e4	55	phys_addr += PAGE_SIZE;
da2c12a2 RK	56	} while (pte++, addr += PAGE_SIZE, addr != end);
da2c12a2 RK	57	return 0;
1da177e4 LT	58
1da177e4 LT	59	bad:
da2c12a2	60	printk(KERN_CRIT "remap_area_pte: page already exists\n");
1da177e4 LT	61	BUG();
	62	}
	63
da2c12a2 RK	64	static inline int remap_area_pmd(pgd_t *pgd, unsigned long addr,
	65	unsigned long end, unsigned long phys_addr,
	66	pgprot_t prot)
1da177e4	67	{
da2c12a2 RK	68	unsigned long next;
	69	pmd_t *pmd;
	70	int ret = 0;
1da177e4	71
da2c12a2 RK	72	pmd = pmd_alloc(&init_mm, pgd, addr);
	73	if (!pmd)
	74	return -ENOMEM;
1da177e4	75
1da177e4	76	do {
da2c12a2 RK	77	next = pmd_addr_end(addr, end);
	78	ret = remap_area_pte(pmd, addr, next, phys_addr, prot);
	79	if (ret)
	80	return ret;
	81	phys_addr += next - addr;
	82	} while (pmd++, addr = next, addr != end);
	83	return ret;
1da177e4 LT	84	}
1da177e4 LT	85
da2c12a2 RK	86	static int remap_area_pages(unsigned long start, unsigned long pfn,
da2c12a2 RK	87	unsigned long size, unsigned long flags)
1da177e4	88	{
da2c12a2 RK	89	unsigned long addr = start;
da2c12a2 RK	90	unsigned long next, end = start + size;
9d4ae727	91	unsigned long phys_addr = __pfn_to_phys(pfn);
da2c12a2 RK	92	pgprot_t prot = __pgprot(L_PTE_PRESENT \| L_PTE_YOUNG \|
	93	L_PTE_DIRTY \| L_PTE_WRITE \| flags);
	94	pgd_t *pgd;
1da177e4	95	int err = 0;
1da177e4	96
da2c12a2 RK	97	BUG_ON(addr >= end);
da2c12a2 RK	98	pgd = pgd_offset_k(addr);
1da177e4	99	do {
da2c12a2 RK	100	next = pgd_addr_end(addr, end);
	101	err = remap_area_pmd(pgd, addr, next, phys_addr, prot);
	102	if (err)
1da177e4	103	break;
da2c12a2 RK	104	phys_addr += next - addr;
da2c12a2 RK	105	} while (pgd++, addr = next, addr != end);
1da177e4	106
1da177e4 LT	107	return err;
	108	}
	109
ff0daca5 RK	110
	111	void __check_kvm_seq(struct mm_struct *mm)
	112	{
	113	unsigned int seq;
	114
	115	do {
	116	seq = init_mm.context.kvm_seq;
	117	memcpy(pgd_offset(mm, VMALLOC_START),
	118	pgd_offset_k(VMALLOC_START),
	119	sizeof(pgd_t) * (pgd_index(VMALLOC_END) -
	120	pgd_index(VMALLOC_START)));
	121	mm->context.kvm_seq = seq;
	122	} while (seq != init_mm.context.kvm_seq);
	123	}
	124
	125	#ifndef CONFIG_SMP
	126	/*
	127	* Section support is unsafe on SMP - If you iounmap and ioremap a region,
	128	* the other CPUs will not see this change until their next context switch.
	129	* Meanwhile, (eg) if an interrupt comes in on one of those other CPUs
	130	* which requires the new ioremap'd region to be referenced, the CPU will
	131	* reference the _old_ region.
	132	*
	133	* Note that get_vm_area() allocates a guard 4K page, so we need to mask
	134	* the size back to 1MB aligned or we will overflow in the loop below.
	135	*/
	136	static void unmap_area_sections(unsigned long virt, unsigned long size)
	137	{
	138	unsigned long addr = virt, end = virt + (size & ~SZ_1M);
	139	pgd_t *pgd;
	140
	141	flush_cache_vunmap(addr, end);
	142	pgd = pgd_offset_k(addr);
	143	do {
	144	pmd_t pmd, *pmdp = pmd_offset(pgd, addr);
	145
	146	pmd = *pmdp;
	147	if (!pmd_none(pmd)) {
	148	/*
	149	* Clear the PMD from the page table, and
	150	* increment the kvm sequence so others
	151	* notice this change.
	152	*
	153	* Note: this is still racy on SMP machines.
	154	*/
	155	pmd_clear(pmdp);
	156	init_mm.context.kvm_seq++;
	157
	158	/*
	159	* Free the page table, if there was one.
	160	*/
	161	if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE)
46a82b2d	162	pte_free_kernel(pmd_page_vaddr(pmd));
ff0daca5 RK	163	}
	164
	165	addr += PGDIR_SIZE;
	166	pgd++;
	167	} while (addr < end);
	168
	169	/*
	170	* Ensure that the active_mm is up to date - we want to
	171	* catch any use-after-iounmap cases.
	172	*/
	173	if (current->active_mm->context.kvm_seq != init_mm.context.kvm_seq)
	174	__check_kvm_seq(current->active_mm);
	175
	176	flush_tlb_kernel_range(virt, end);
	177	}
	178
	179	static int
	180	remap_area_sections(unsigned long virt, unsigned long pfn,
	181	unsigned long size, unsigned long flags)
	182	{
	183	unsigned long prot, addr = virt, end = virt + size;
	184	pgd_t *pgd;
	185
	186	/*
	187	* Remove and free any PTE-based mapping, and
	188	* sync the current kernel mapping.
	189	*/
	190	unmap_area_sections(virt, size);
	191
	192	prot = PMD_TYPE_SECT \| PMD_SECT_AP_WRITE \| PMD_DOMAIN(DOMAIN_IO) \|
	193	(flags & (L_PTE_CACHEABLE \| L_PTE_BUFFERABLE));
	194
	195	/*
	196	* ARMv6 and above need XN set to prevent speculative prefetches
	197	* hitting IO.
	198	*/
	199	if (cpu_architecture() >= CPU_ARCH_ARMv6)
	200	prot \|= PMD_SECT_XN;
	201
	202	pgd = pgd_offset_k(addr);
	203	do {
	204	pmd_t *pmd = pmd_offset(pgd, addr);
	205
	206	pmd[0] = __pmd(__pfn_to_phys(pfn) \| prot);
	207	pfn += SZ_1M >> PAGE_SHIFT;
	208	pmd[1] = __pmd(__pfn_to_phys(pfn) \| prot);
	209	pfn += SZ_1M >> PAGE_SHIFT;
	210	flush_pmd_entry(pmd);
	211
	212	addr += PGDIR_SIZE;
	213	pgd++;
	214	} while (addr < end);
	215
	216	return 0;
	217	}
a069c896 LB	218
	219	static int
	220	remap_area_supersections(unsigned long virt, unsigned long pfn,
	221	unsigned long size, unsigned long flags)
	222	{
	223	unsigned long prot, addr = virt, end = virt + size;
	224	pgd_t *pgd;
	225
	226	/*
	227	* Remove and free any PTE-based mapping, and
	228	* sync the current kernel mapping.
	229	*/
	230	unmap_area_sections(virt, size);
	231
	232	prot = PMD_TYPE_SECT \| PMD_SECT_SUPER \| PMD_SECT_AP_WRITE \|
	233	PMD_DOMAIN(DOMAIN_IO) \|
	234	(flags & (L_PTE_CACHEABLE \| L_PTE_BUFFERABLE));
	235
	236	/*
	237	* ARMv6 and above need XN set to prevent speculative prefetches
	238	* hitting IO.
	239	*/
	240	if (cpu_architecture() >= CPU_ARCH_ARMv6)
	241	prot \|= PMD_SECT_XN;
	242
	243	pgd = pgd_offset_k(virt);
	244	do {
	245	unsigned long super_pmd_val, i;
	246
	247	super_pmd_val = __pfn_to_phys(pfn) \| prot;
	248	super_pmd_val \|= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20;
	249
	250	for (i = 0; i < 8; i++) {
	251	pmd_t *pmd = pmd_offset(pgd, addr);
	252
	253	pmd[0] = __pmd(super_pmd_val);
	254	pmd[1] = __pmd(super_pmd_val);
	255	flush_pmd_entry(pmd);
	256
	257	addr += PGDIR_SIZE;
	258	pgd++;
	259	}
	260
	261	pfn += SUPERSECTION_SIZE >> PAGE_SHIFT;
	262	} while (addr < end);
	263
	264	return 0;
	265	}
ff0daca5 RK	266	#endif
	267
	268
1da177e4 LT	269	/*
	270	* Remap an arbitrary physical address space into the kernel virtual
	271	* address space. Needed when the kernel wants to access high addresses
	272	* directly.
	273	*
	274	* NOTE! We need to allow non-page-aligned mappings too: we will obviously
	275	* have to convert them into an offset in a page-aligned mapping, but the
	276	* caller shouldn't need to know that small detail.
	277	*
	278	* 'flags' are the extra L_PTE_ flags that you want to specify for this
	279	* mapping. See include/asm-arm/proc-armv/pgtable.h for more information.
	280	*/
9d4ae727 DS	281	void __iomem *
	282	__ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
	283	unsigned long flags)
	284	{
ff0daca5	285	int err;
9d4ae727 DS	286	unsigned long addr;
9d4ae727 DS	287	struct vm_struct * area;
a069c896 LB	288
	289	/*
	290	* High mappings must be supersection aligned
	291	*/
	292	if (pfn >= 0x100000 && (__pfn_to_phys(pfn) & ~SUPERSECTION_MASK))
	293	return NULL;
9d4ae727 DS	294
	295	area = get_vm_area(size, VM_IOREMAP);
	296	if (!area)
	297	return NULL;
	298	addr = (unsigned long)area->addr;
ff0daca5 RK	299
ff0daca5 RK	300	#ifndef CONFIG_SMP
67f3a588	301	if ((((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) \|\|
a069c896 LB	302	cpu_is_xsc3()) &&
	303	!((__pfn_to_phys(pfn) \| size \| addr) & ~SUPERSECTION_MASK)) {
	304	area->flags \|= VM_ARM_SECTION_MAPPING;
	305	err = remap_area_supersections(addr, pfn, size, flags);
	306	} else if (!((__pfn_to_phys(pfn) \| size \| addr) & ~PMD_MASK)) {
ff0daca5 RK	307	area->flags \|= VM_ARM_SECTION_MAPPING;
	308	err = remap_area_sections(addr, pfn, size, flags);
	309	} else
	310	#endif
	311	err = remap_area_pages(addr, pfn, size, flags);
	312
	313	if (err) {
478922c2	314	vunmap((void *)addr);
9d4ae727 DS	315	return NULL;
9d4ae727 DS	316	}
ff0daca5 RK	317
	318	flush_cache_vmap(addr, addr + size);
	319	return (void __iomem *) (offset + addr);
9d4ae727 DS	320	}
	321	EXPORT_SYMBOL(__ioremap_pfn);
	322
1da177e4	323	void __iomem *
67a1901f	324	__ioremap(unsigned long phys_addr, size_t size, unsigned long flags)
1da177e4	325	{
9d4ae727 DS	326	unsigned long last_addr;
	327	unsigned long offset = phys_addr & ~PAGE_MASK;
	328	unsigned long pfn = __phys_to_pfn(phys_addr);
1da177e4	329
9d4ae727 DS	330	/*
	331	* Don't allow wraparound or zero size
	332	*/
1da177e4 LT	333	last_addr = phys_addr + size - 1;
	334	if (!size \|\| last_addr < phys_addr)
	335	return NULL;
	336
	337	/*
9d4ae727	338	* Page align the mapping size
1da177e4	339	*/
1da177e4 LT	340	size = PAGE_ALIGN(last_addr + 1) - phys_addr;
1da177e4 LT	341
9d4ae727	342	return __ioremap_pfn(pfn, offset, size, flags);
1da177e4 LT	343	}
	344	EXPORT_SYMBOL(__ioremap);
	345
1622605c	346	void __iounmap(volatile void __iomem *addr)
1da177e4	347	{
ceaccbd2	348	#ifndef CONFIG_SMP
ff0daca5	349	struct vm_struct *p, tmp;
ceaccbd2	350	#endif
ff0daca5 RK	351	unsigned int section_mapping = 0;
ff0daca5 RK	352
1622605c	353	addr = (volatile void __iomem *)(PAGE_MASK & (unsigned long)addr);
ff0daca5	354
7cddc397	355	#ifndef CONFIG_SMP
ff0daca5 RK	356	/*
	357	* If this is a section based mapping we need to handle it
	358	* specially as the VM subysystem does not know how to handle
	359	* such a beast. We need the lock here b/c we need to clear
	360	* all the mappings before the area can be reclaimed
	361	* by someone else.
	362	*/
	363	write_lock(&vmlist_lock);
	364	for (p = &vmlist ; (tmp = *p) ; p = &tmp->next) {
	365	if((tmp->flags & VM_IOREMAP) && (tmp->addr == addr)) {
	366	if (tmp->flags & VM_ARM_SECTION_MAPPING) {
	367	*p = tmp->next;
	368	unmap_area_sections((unsigned long)tmp->addr,
	369	tmp->size);
	370	kfree(tmp);
	371	section_mapping = 1;
	372	}
	373	break;
	374	}
	375	}
	376	write_unlock(&vmlist_lock);
7cddc397	377	#endif
ff0daca5 RK	378
ff0daca5 RK	379	if (!section_mapping)
1622605c	380	vunmap((void __force *)addr);
1da177e4 LT	381	}
1da177e4 LT	382	EXPORT_SYMBOL(__iounmap);