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

/*
 * arch/sh/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
 * (C) Copyright 2005, 2006 Paul Mundt
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License. See the file "COPYING" in the main directory of this
 * archive for more details.
 */
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/pci.h>
#include <asm/io.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/addrspace.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>

static inline void remap_area_pte(pte_t * pte, unsigned long address,
	unsigned long size, unsigned long phys_addr, unsigned long flags)
{
	unsigned long end;
	unsigned long pfn;
	pgprot_t pgprot = __pgprot(pgprot_val(PAGE_KERNEL_NOCACHE) | flags);

	address &= ~PMD_MASK;
	end = address + size;
	if (end > PMD_SIZE)
		end = PMD_SIZE;
	if (address >= end)
		BUG();
	pfn = phys_addr >> PAGE_SHIFT;
	do {
		if (!pte_none(*pte)) {
			printk("remap_area_pte: page already exists\n");
			BUG();
		}
		set_pte(pte, pfn_pte(pfn, pgprot));
		address += PAGE_SIZE;
		pfn++;
		pte++;
	} while (address && (address < end));
}

static inline int remap_area_pmd(pmd_t * pmd, unsigned long address,
	unsigned long size, unsigned long phys_addr, unsigned long flags)
{
	unsigned long end;

	address &= ~PGDIR_MASK;
	end = address + size;
	if (end > PGDIR_SIZE)
		end = PGDIR_SIZE;
	phys_addr -= address;
	if (address >= end)
		BUG();
	do {
		pte_t * pte = pte_alloc_kernel(pmd, address);
		if (!pte)
			return -ENOMEM;
		remap_area_pte(pte, address, end - address, address + phys_addr, flags);
		address = (address + PMD_SIZE) & PMD_MASK;
		pmd++;
	} while (address && (address < end));
	return 0;
}

int remap_area_pages(unsigned long address, unsigned long phys_addr,
		     unsigned long size, unsigned long flags)
{
	int error;
	pgd_t * dir;
	unsigned long end = address + size;

	phys_addr -= address;
	dir = pgd_offset_k(address);
	flush_cache_all();
	if (address >= end)
		BUG();
	do {
		pud_t *pud;
		pmd_t *pmd;

		error = -ENOMEM;

		pud = pud_alloc(&init_mm, dir, address);
		if (!pud)
			break;
		pmd = pmd_alloc(&init_mm, pud, address);
		if (!pmd)
			break;
		if (remap_area_pmd(pmd, address, end - address,
					phys_addr + address, flags))
			break;
		error = 0;
		address = (address + PGDIR_SIZE) & PGDIR_MASK;
		dir++;
	} while (address && (address < end));
	flush_tlb_all();
	return error;
}

/*
 * 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)
{
	struct vm_struct * area;
	unsigned long offset, last_addr, addr, orig_addr;

	/* 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 >= 0xA0000 && last_addr < 0x100000)
		return (void __iomem *)phys_to_virt(phys_addr);

	/*
	 * If we're on an SH7751 or SH7780 PCI controller, PCI memory is
	 * mapped at the end of the address space (typically 0xfd000000)
	 * in a non-translatable area, so mapping through page tables for
	 * this area is not only pointless, but also fundamentally
	 * broken. Just return the physical address instead.
	 *
	 * For boards that map a small PCI memory aperture somewhere in
	 * P1/P2 space, ioremap() will already do the right thing,
	 * and we'll never get this far.
	 */
	if (is_pci_memaddr(phys_addr) && is_pci_memaddr(last_addr))
		return (void __iomem *)phys_addr;

	/*
	 * Don't allow anybody to remap normal RAM that we're using..
	 */
	if (phys_addr < virt_to_phys(high_memory))
		return NULL;

	/*
	 * 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;
	orig_addr = addr = (unsigned long)area->addr;

#ifdef CONFIG_32BIT
	/*
	 * First try to remap through the PMB once a valid VMA has been
	 * established. Smaller allocations (or the rest of the size
	 * remaining after a PMB mapping due to the size not being
	 * perfectly aligned on a PMB size boundary) are then mapped
	 * through the UTLB using conventional page tables.
	 *
	 * PMB entries are all pre-faulted.
	 */
	if (unlikely(size >= 0x1000000)) {
		unsigned long mapped = pmb_remap(addr, phys_addr, size, flags);

		if (likely(mapped)) {
			addr		+= mapped;
			phys_addr	+= mapped;
			size		-= mapped;
		}
	}
#endif

	if (likely(size))
		if (remap_area_pages(addr, phys_addr, size, flags)) {
			vunmap((void *)orig_addr);
			return NULL;
		}

	return (void __iomem *)(offset + (char *)orig_addr);
}
EXPORT_SYMBOL(__ioremap);

void __iounmap(void __iomem *addr)
{
	unsigned long vaddr = (unsigned long __force)addr;
	struct vm_struct *p;

	if (PXSEG(vaddr) < P3SEG || is_pci_memaddr(vaddr))
		return;

#ifdef CONFIG_32BIT
	/*
	 * Purge any PMB entries that may have been established for this
	 * mapping, then proceed with conventional VMA teardown.
	 *
	 * XXX: Note that due to the way that remove_vm_area() does
	 * matching of the resultant VMA, we aren't able to fast-forward
	 * the address past the PMB space until the end of the VMA where
	 * the page tables reside. As such, unmap_vm_area() will be
	 * forced to linearly scan over the area until it finds the page
	 * tables where PTEs that need to be unmapped actually reside,
	 * which is far from optimal. Perhaps we need to use a separate
	 * VMA for the PMB mappings?
	 *					-- PFM.
	 */
	pmb_unmap(vaddr);
#endif

	p = remove_vm_area((void *)(vaddr & PAGE_MASK));
	if (!p) {
		printk(KERN_ERR "%s: bad address %p\n", __FUNCTION__, addr);
		return;
	}

	kfree(p);
}
EXPORT_SYMBOL(__iounmap);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* arch/sh/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
b66c1a39 PM	9	* (C) Copyright 2005, 2006 Paul Mundt
	10	*
	11	* This file is subject to the terms and conditions of the GNU General
	12	* Public License. See the file "COPYING" in the main directory of this
	13	* archive for more details.
1da177e4	14	*/
1da177e4	15	#include <linux/vmalloc.h>
b66c1a39	16	#include <linux/module.h>
1da177e4	17	#include <linux/mm.h>
a3e61d50	18	#include <linux/pci.h>
1da177e4 LT	19	#include <asm/io.h>
	20	#include <asm/page.h>
	21	#include <asm/pgalloc.h>
b66c1a39	22	#include <asm/addrspace.h>
1da177e4 LT	23	#include <asm/cacheflush.h>
	24	#include <asm/tlbflush.h>
	25
	26	static inline void remap_area_pte(pte_t * pte, unsigned long address,
	27	unsigned long size, unsigned long phys_addr, unsigned long flags)
	28	{
	29	unsigned long end;
	30	unsigned long pfn;
21440cf0	31	pgprot_t pgprot = __pgprot(pgprot_val(PAGE_KERNEL_NOCACHE) \| flags);
1da177e4 LT	32
	33	address &= ~PMD_MASK;
	34	end = address + size;
	35	if (end > PMD_SIZE)
	36	end = PMD_SIZE;
	37	if (address >= end)
	38	BUG();
	39	pfn = phys_addr >> PAGE_SHIFT;
	40	do {
	41	if (!pte_none(*pte)) {
	42	printk("remap_area_pte: page already exists\n");
	43	BUG();
	44	}
	45	set_pte(pte, pfn_pte(pfn, pgprot));
	46	address += PAGE_SIZE;
	47	pfn++;
	48	pte++;
	49	} while (address && (address < end));
	50	}
	51
	52	static inline int remap_area_pmd(pmd_t * pmd, unsigned long address,
	53	unsigned long size, unsigned long phys_addr, unsigned long flags)
	54	{
	55	unsigned long end;
	56
	57	address &= ~PGDIR_MASK;
	58	end = address + size;
	59	if (end > PGDIR_SIZE)
	60	end = PGDIR_SIZE;
	61	phys_addr -= address;
	62	if (address >= end)
	63	BUG();
	64	do {
872fec16	65	pte_t * pte = pte_alloc_kernel(pmd, address);
1da177e4 LT	66	if (!pte)
	67	return -ENOMEM;
	68	remap_area_pte(pte, address, end - address, address + phys_addr, flags);
	69	address = (address + PMD_SIZE) & PMD_MASK;
	70	pmd++;
	71	} while (address && (address < end));
	72	return 0;
	73	}
	74
	75	int remap_area_pages(unsigned long address, unsigned long phys_addr,
	76	unsigned long size, unsigned long flags)
	77	{
	78	int error;
	79	pgd_t * dir;
	80	unsigned long end = address + size;
	81
	82	phys_addr -= address;
	83	dir = pgd_offset_k(address);
	84	flush_cache_all();
	85	if (address >= end)
	86	BUG();
1da177e4	87	do {
b66c1a39	88	pud_t *pud;
1da177e4	89	pmd_t *pmd;
b66c1a39	90
1da177e4	91	error = -ENOMEM;
b66c1a39 PM	92
	93	pud = pud_alloc(&init_mm, dir, address);
	94	if (!pud)
	95	break;
	96	pmd = pmd_alloc(&init_mm, pud, address);
1da177e4 LT	97	if (!pmd)
	98	break;
	99	if (remap_area_pmd(pmd, address, end - address,
	100	phys_addr + address, flags))
	101	break;
	102	error = 0;
	103	address = (address + PGDIR_SIZE) & PGDIR_MASK;
	104	dir++;
	105	} while (address && (address < end));
1da177e4 LT	106	flush_tlb_all();
	107	return error;
	108	}
	109
1da177e4 LT	110	/*
	111	* Remap an arbitrary physical address space into the kernel virtual
	112	* address space. Needed when the kernel wants to access high addresses
	113	* directly.
	114	*
	115	* NOTE! We need to allow non-page-aligned mappings too: we will obviously
	116	* have to convert them into an offset in a page-aligned mapping, but the
	117	* caller shouldn't need to know that small detail.
	118	*/
b66c1a39 PM	119	void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
b66c1a39 PM	120	unsigned long flags)
1da177e4	121	{
1da177e4	122	struct vm_struct * area;
b66c1a39	123	unsigned long offset, last_addr, addr, orig_addr;
1da177e4 LT	124
	125	/* Don't allow wraparound or zero size */
	126	last_addr = phys_addr + size - 1;
	127	if (!size \|\| last_addr < phys_addr)
	128	return NULL;
	129
	130	/*
	131	* Don't remap the low PCI/ISA area, it's always mapped..
	132	*/
	133	if (phys_addr >= 0xA0000 && last_addr < 0x100000)
b66c1a39	134	return (void __iomem *)phys_to_virt(phys_addr);
1da177e4	135
a3e61d50 PM	136	/*
	137	* If we're on an SH7751 or SH7780 PCI controller, PCI memory is
	138	* mapped at the end of the address space (typically 0xfd000000)
	139	* in a non-translatable area, so mapping through page tables for
	140	* this area is not only pointless, but also fundamentally
	141	* broken. Just return the physical address instead.
	142	*
	143	* For boards that map a small PCI memory aperture somewhere in
	144	* P1/P2 space, ioremap() will already do the right thing,
	145	* and we'll never get this far.
	146	*/
	147	if (is_pci_memaddr(phys_addr) && is_pci_memaddr(last_addr))
	148	return (void __iomem *)phys_addr;
	149
1da177e4 LT	150	/*
	151	* Don't allow anybody to remap normal RAM that we're using..
	152	*/
	153	if (phys_addr < virt_to_phys(high_memory))
	154	return NULL;
	155
	156	/*
	157	* Mappings have to be page-aligned
	158	*/
	159	offset = phys_addr & ~PAGE_MASK;
	160	phys_addr &= PAGE_MASK;
	161	size = PAGE_ALIGN(last_addr+1) - phys_addr;
	162
	163	/*
	164	* Ok, go for it..
	165	*/
	166	area = get_vm_area(size, VM_IOREMAP);
	167	if (!area)
	168	return NULL;
	169	area->phys_addr = phys_addr;
b66c1a39 PM	170	orig_addr = addr = (unsigned long)area->addr;
	171
	172	#ifdef CONFIG_32BIT
	173	/*
	174	* First try to remap through the PMB once a valid VMA has been
	175	* established. Smaller allocations (or the rest of the size
	176	* remaining after a PMB mapping due to the size not being
	177	* perfectly aligned on a PMB size boundary) are then mapped
	178	* through the UTLB using conventional page tables.
	179	*
	180	* PMB entries are all pre-faulted.
	181	*/
	182	if (unlikely(size >= 0x1000000)) {
	183	unsigned long mapped = pmb_remap(addr, phys_addr, size, flags);
	184
	185	if (likely(mapped)) {
	186	addr += mapped;
	187	phys_addr += mapped;
	188	size -= mapped;
	189	}
1da177e4	190	}
b66c1a39 PM	191	#endif
	192
	193	if (likely(size))
	194	if (remap_area_pages(addr, phys_addr, size, flags)) {
	195	vunmap((void *)orig_addr);
	196	return NULL;
	197	}
	198
	199	return (void __iomem )(offset + (char )orig_addr);
1da177e4	200	}
b66c1a39	201	EXPORT_SYMBOL(__ioremap);
1da177e4	202
b66c1a39	203	void __iounmap(void __iomem *addr)
1da177e4	204	{
b66c1a39 PM	205	unsigned long vaddr = (unsigned long __force)addr;
	206	struct vm_struct *p;
	207
a3e61d50	208	if (PXSEG(vaddr) < P3SEG \|\| is_pci_memaddr(vaddr))
b66c1a39 PM	209	return;
	210
	211	#ifdef CONFIG_32BIT
	212	/*
	213	* Purge any PMB entries that may have been established for this
	214	* mapping, then proceed with conventional VMA teardown.
	215	*
	216	* XXX: Note that due to the way that remove_vm_area() does
	217	* matching of the resultant VMA, we aren't able to fast-forward
	218	* the address past the PMB space until the end of the VMA where
	219	* the page tables reside. As such, unmap_vm_area() will be
	220	* forced to linearly scan over the area until it finds the page
	221	* tables where PTEs that need to be unmapped actually reside,
	222	* which is far from optimal. Perhaps we need to use a separate
	223	* VMA for the PMB mappings?
	224	* -- PFM.
	225	*/
	226	pmb_unmap(vaddr);
	227	#endif
	228
	229	p = remove_vm_area((void *)(vaddr & PAGE_MASK));
	230	if (!p) {
	231	printk(KERN_ERR "%s: bad address %p\n", __FUNCTION__, addr);
	232	return;
	233	}
	234
	235	kfree(p);
1da177e4	236	}
b66c1a39	237	EXPORT_SYMBOL(__iounmap);