[linux-2.6-block.git] / arch / microblaze / mm / pgtable.c

/*
 *  This file contains the routines setting up the linux page tables.
 *
 * Copyright (C) 2008 Michal Simek
 * Copyright (C) 2008 PetaLogix
 *
 *    Copyright (C) 2007 Xilinx, Inc.  All rights reserved.
 *
 *  Derived from arch/ppc/mm/pgtable.c:
 *    -- paulus
 *
 *  Derived from arch/ppc/mm/init.c:
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
 *    Copyright (C) 1996 Paul Mackerras
 *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
 *
 *  Derived from "arch/i386/mm/init.c"
 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *
 *  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/export.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/vmalloc.h>
#include <linux/init.h>

#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <linux/io.h>
#include <asm/mmu.h>
#include <asm/sections.h>
#include <asm/fixmap.h>

unsigned long ioremap_base;
unsigned long ioremap_bot;
EXPORT_SYMBOL(ioremap_bot);

#ifndef CONFIG_SMP
struct pgtable_cache_struct quicklists;
#endif

static void __iomem *__ioremap(phys_addr_t addr, unsigned long size,
		unsigned long flags)
{
	unsigned long v, i;
	phys_addr_t p;
	int err;

	/*
	 * Choose an address to map it to.
	 * Once the vmalloc system is running, we use it.
	 * Before then, we use space going down from ioremap_base
	 * (ioremap_bot records where we're up to).
	 */
	p = addr & PAGE_MASK;
	size = PAGE_ALIGN(addr + size) - p;

	/*
	 * Don't allow anybody to remap normal RAM that we're using.
	 * mem_init() sets high_memory so only do the check after that.
	 *
	 * However, allow remap of rootfs: TBD
	 */

	if (mem_init_done &&
		p >= memory_start && p < virt_to_phys(high_memory) &&
		!(p >= __virt_to_phys((phys_addr_t)__bss_stop) &&
		p < __virt_to_phys((phys_addr_t)__bss_stop))) {
		pr_warn("__ioremap(): phys addr "PTE_FMT" is RAM lr %pf\n",
			(unsigned long)p, __builtin_return_address(0));
		return NULL;
	}

	if (size == 0)
		return NULL;

	/*
	 * Is it already mapped? If the whole area is mapped then we're
	 * done, otherwise remap it since we want to keep the virt addrs for
	 * each request contiguous.
	 *
	 * We make the assumption here that if the bottom and top
	 * of the range we want are mapped then it's mapped to the
	 * same virt address (and this is contiguous).
	 *  -- Cort
	 */

	if (mem_init_done) {
		struct vm_struct *area;
		area = get_vm_area(size, VM_IOREMAP);
		if (area == NULL)
			return NULL;
		v = (unsigned long) area->addr;
	} else {
		v = (ioremap_bot -= size);
	}

	if ((flags & _PAGE_PRESENT) == 0)
		flags |= _PAGE_KERNEL;
	if (flags & _PAGE_NO_CACHE)
		flags |= _PAGE_GUARDED;

	err = 0;
	for (i = 0; i < size && err == 0; i += PAGE_SIZE)
		err = map_page(v + i, p + i, flags);
	if (err) {
		if (mem_init_done)
			vfree((void *)v);
		return NULL;
	}

	return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
}

void __iomem *ioremap(phys_addr_t addr, unsigned long size)
{
	return __ioremap(addr, size, _PAGE_NO_CACHE);
}
EXPORT_SYMBOL(ioremap);

void iounmap(void __iomem *addr)
{
	if ((__force void *)addr > high_memory &&
					(unsigned long) addr < ioremap_bot)
		vfree((void *) (PAGE_MASK & (unsigned long) addr));
}
EXPORT_SYMBOL(iounmap);


int map_page(unsigned long va, phys_addr_t pa, int flags)
{
	pmd_t *pd;
	pte_t *pg;
	int err = -ENOMEM;
	/* Use upper 10 bits of VA to index the first level map */
	pd = pmd_offset(pgd_offset_k(va), va);
	/* Use middle 10 bits of VA to index the second-level map */
	pg = pte_alloc_kernel(pd, va); /* from powerpc - pgtable.c */
	/* pg = pte_alloc_kernel(&init_mm, pd, va); */

	if (pg != NULL) {
		err = 0;
		set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
				__pgprot(flags)));
		if (unlikely(mem_init_done))
			_tlbie(va);
	}
	return err;
}

/*
 * Map in all of physical memory starting at CONFIG_KERNEL_START.
 */
void __init mapin_ram(void)
{
	unsigned long v, p, s, f;

	v = CONFIG_KERNEL_START;
	p = memory_start;
	for (s = 0; s < lowmem_size; s += PAGE_SIZE) {
		f = _PAGE_PRESENT | _PAGE_ACCESSED |
				_PAGE_SHARED | _PAGE_HWEXEC;
		if ((char *) v < _stext || (char *) v >= _etext)
			f |= _PAGE_WRENABLE;
		else
			/* On the MicroBlaze, no user access
			   forces R/W kernel access */
			f |= _PAGE_USER;
		map_page(v, p, f);
		v += PAGE_SIZE;
		p += PAGE_SIZE;
	}
}

/* is x a power of 2? */
#define is_power_of_2(x)	((x) != 0 && (((x) & ((x) - 1)) == 0))

/* Scan the real Linux page tables and return a PTE pointer for
 * a virtual address in a context.
 * Returns true (1) if PTE was found, zero otherwise.  The pointer to
 * the PTE pointer is unmodified if PTE is not found.
 */
static int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep)
{
	pgd_t	*pgd;
	pmd_t	*pmd;
	pte_t	*pte;
	int     retval = 0;

	pgd = pgd_offset(mm, addr & PAGE_MASK);
	if (pgd) {
		pmd = pmd_offset(pgd, addr & PAGE_MASK);
		if (pmd_present(*pmd)) {
			pte = pte_offset_kernel(pmd, addr & PAGE_MASK);
			if (pte) {
				retval = 1;
				*ptep = pte;
			}
		}
	}
	return retval;
}

/* Find physical address for this virtual address.  Normally used by
 * I/O functions, but anyone can call it.
 */
unsigned long iopa(unsigned long addr)
{
	unsigned long pa;

	pte_t *pte;
	struct mm_struct *mm;

	/* Allow mapping of user addresses (within the thread)
	 * for DMA if necessary.
	 */
	if (addr < TASK_SIZE)
		mm = current->mm;
	else
		mm = &init_mm;

	pa = 0;
	if (get_pteptr(mm, addr, &pte))
		pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK);

	return pa;
}

__init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
		unsigned long address)
{
	pte_t *pte;
	if (mem_init_done) {
		pte = (pte_t *)__get_free_page(GFP_KERNEL |
					__GFP_REPEAT | __GFP_ZERO);
	} else {
		pte = (pte_t *)early_get_page();
		if (pte)
			clear_page(pte);
	}
	return pte;
}

void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
{
	unsigned long address = __fix_to_virt(idx);

	if (idx >= __end_of_fixed_addresses)
		BUG();

	map_page(address, phys, pgprot_val(flags));
}
Commit	Line	Data
15902bf6 MS	1	/*
	2	* This file contains the routines setting up the linux page tables.
	3	*
	4	* Copyright (C) 2008 Michal Simek
	5	* Copyright (C) 2008 PetaLogix
	6	*
	7	* Copyright (C) 2007 Xilinx, Inc. All rights reserved.
	8	*
	9	* Derived from arch/ppc/mm/pgtable.c:
	10	* -- paulus
	11	*
	12	* Derived from arch/ppc/mm/init.c:
	13	* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
	14	*
	15	* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
	16	* and Cort Dougan (PReP) (cort@cs.nmt.edu)
	17	* Copyright (C) 1996 Paul Mackerras
	18	* Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
	19	*
	20	* Derived from "arch/i386/mm/init.c"
	21	* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
	22	*
	23	* This file is subject to the terms and conditions of the GNU General
	24	* Public License. See the file COPYING in the main directory of this
	25	* archive for more details.
	26	*
	27	*/
	28
d64af918	29	#include <linux/export.h>
15902bf6	30	#include <linux/kernel.h>
15902bf6 MS	31	#include <linux/types.h>
	32	#include <linux/vmalloc.h>
	33	#include <linux/init.h>
	34
	35	#include <asm/pgtable.h>
	36	#include <asm/pgalloc.h>
	37	#include <linux/io.h>
	38	#include <asm/mmu.h>
	39	#include <asm/sections.h>
41938761	40	#include <asm/fixmap.h>
15902bf6	41
15902bf6 MS	42	unsigned long ioremap_base;
15902bf6 MS	43	unsigned long ioremap_bot;
ee4bcdf1	44	EXPORT_SYMBOL(ioremap_bot);
15902bf6	45
15902bf6 MS	46	#ifndef CONFIG_SMP
	47	struct pgtable_cache_struct quicklists;
	48	#endif
	49
	50	static void __iomem *__ioremap(phys_addr_t addr, unsigned long size,
	51	unsigned long flags)
	52	{
	53	unsigned long v, i;
	54	phys_addr_t p;
	55	int err;
	56
	57	/*
	58	* Choose an address to map it to.
	59	* Once the vmalloc system is running, we use it.
	60	* Before then, we use space going down from ioremap_base
	61	* (ioremap_bot records where we're up to).
	62	*/
	63	p = addr & PAGE_MASK;
	64	size = PAGE_ALIGN(addr + size) - p;
	65
	66	/*
	67	* Don't allow anybody to remap normal RAM that we're using.
	68	* mem_init() sets high_memory so only do the check after that.
	69	*
	70	* However, allow remap of rootfs: TBD
	71	*/
a66a6265	72
15902bf6 MS	73	if (mem_init_done &&
15902bf6 MS	74	p >= memory_start && p < virt_to_phys(high_memory) &&
a66a6265 MS	75	!(p >= __virt_to_phys((phys_addr_t)__bss_stop) &&
a66a6265 MS	76	p < __virt_to_phys((phys_addr_t)__bss_stop))) {
6bd55f0b MS	77	pr_warn("__ioremap(): phys addr "PTE_FMT" is RAM lr %pf\n",
6bd55f0b MS	78	(unsigned long)p, __builtin_return_address(0));
15902bf6 MS	79	return NULL;
	80	}
	81
	82	if (size == 0)
	83	return NULL;
	84
	85	/*
	86	* Is it already mapped? If the whole area is mapped then we're
	87	* done, otherwise remap it since we want to keep the virt addrs for
	88	* each request contiguous.
	89	*
	90	* We make the assumption here that if the bottom and top
	91	* of the range we want are mapped then it's mapped to the
	92	* same virt address (and this is contiguous).
	93	* -- Cort
	94	*/
	95
	96	if (mem_init_done) {
	97	struct vm_struct *area;
	98	area = get_vm_area(size, VM_IOREMAP);
	99	if (area == NULL)
	100	return NULL;
cca5613f	101	v = (unsigned long) area->addr;
15902bf6 MS	102	} else {
	103	v = (ioremap_bot -= size);
	104	}
	105
	106	if ((flags & _PAGE_PRESENT) == 0)
	107	flags \|= _PAGE_KERNEL;
	108	if (flags & _PAGE_NO_CACHE)
	109	flags \|= _PAGE_GUARDED;
	110
	111	err = 0;
	112	for (i = 0; i < size && err == 0; i += PAGE_SIZE)
	113	err = map_page(v + i, p + i, flags);
	114	if (err) {
	115	if (mem_init_done)
	116	vfree((void *)v);
	117	return NULL;
	118	}
	119
	120	return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
	121	}
	122
	123	void __iomem *ioremap(phys_addr_t addr, unsigned long size)
	124	{
	125	return __ioremap(addr, size, _PAGE_NO_CACHE);
	126	}
	127	EXPORT_SYMBOL(ioremap);
	128
6bd55f0b	129	void iounmap(void __iomem *addr)
15902bf6	130	{
6bd55f0b MS	131	if ((__force void *)addr > high_memory &&
6bd55f0b MS	132	(unsigned long) addr < ioremap_bot)
15902bf6 MS	133	vfree((void *) (PAGE_MASK & (unsigned long) addr));
	134	}
	135	EXPORT_SYMBOL(iounmap);
	136
	137
	138	int map_page(unsigned long va, phys_addr_t pa, int flags)
	139	{
	140	pmd_t *pd;
	141	pte_t *pg;
	142	int err = -ENOMEM;
15902bf6 MS	143	/* Use upper 10 bits of VA to index the first level map */
	144	pd = pmd_offset(pgd_offset_k(va), va);
	145	/* Use middle 10 bits of VA to index the second-level map */
	146	pg = pte_alloc_kernel(pd, va); /* from powerpc - pgtable.c */
	147	/* pg = pte_alloc_kernel(&init_mm, pd, va); */
	148
	149	if (pg != NULL) {
	150	err = 0;
	151	set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
	152	__pgprot(flags)));
78ebfa88	153	if (unlikely(mem_init_done))
6bd55f0b	154	_tlbie(va);
15902bf6	155	}
15902bf6 MS	156	return err;
	157	}
	158
15902bf6 MS	159	/*
	160	* Map in all of physical memory starting at CONFIG_KERNEL_START.
	161	*/
	162	void __init mapin_ram(void)
	163	{
	164	unsigned long v, p, s, f;
	165
	166	v = CONFIG_KERNEL_START;
	167	p = memory_start;
7c0d2615	168	for (s = 0; s < lowmem_size; s += PAGE_SIZE) {
15902bf6 MS	169	f = _PAGE_PRESENT \| _PAGE_ACCESSED \|
	170	_PAGE_SHARED \| _PAGE_HWEXEC;
	171	if ((char ) v < _stext \|\| (char ) v >= _etext)
	172	f \|= _PAGE_WRENABLE;
	173	else
	174	/* On the MicroBlaze, no user access
	175	forces R/W kernel access */
	176	f \|= _PAGE_USER;
	177	map_page(v, p, f);
	178	v += PAGE_SIZE;
	179	p += PAGE_SIZE;
	180	}
	181	}
	182
	183	/* is x a power of 2? */
	184	#define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0))
	185
15902bf6 MS	186	/* Scan the real Linux page tables and return a PTE pointer for
	187	* a virtual address in a context.
	188	* Returns true (1) if PTE was found, zero otherwise. The pointer to
	189	* the PTE pointer is unmodified if PTE is not found.
	190	*/
	191	static int get_pteptr(struct mm_struct mm, unsigned long addr, pte_t *ptep)
	192	{
	193	pgd_t *pgd;
	194	pmd_t *pmd;
	195	pte_t *pte;
	196	int retval = 0;
	197
	198	pgd = pgd_offset(mm, addr & PAGE_MASK);
	199	if (pgd) {
	200	pmd = pmd_offset(pgd, addr & PAGE_MASK);
	201	if (pmd_present(*pmd)) {
	202	pte = pte_offset_kernel(pmd, addr & PAGE_MASK);
	203	if (pte) {
	204	retval = 1;
	205	*ptep = pte;
	206	}
	207	}
	208	}
	209	return retval;
	210	}
	211
	212	/* Find physical address for this virtual address. Normally used by
	213	* I/O functions, but anyone can call it.
	214	*/
	215	unsigned long iopa(unsigned long addr)
	216	{
	217	unsigned long pa;
	218
	219	pte_t *pte;
	220	struct mm_struct *mm;
	221
	222	/* Allow mapping of user addresses (within the thread)
	223	* for DMA if necessary.
	224	*/
	225	if (addr < TASK_SIZE)
	226	mm = current->mm;
	227	else
	228	mm = &init_mm;
	229
	230	pa = 0;
	231	if (get_pteptr(mm, addr, &pte))
	232	pa = (pte_val(*pte) & PAGE_MASK) \| (addr & ~PAGE_MASK);
	233
	234	return pa;
	235	}
63f1032b MS	236
	237	__init_refok pte_t pte_alloc_one_kernel(struct mm_struct mm,
	238	unsigned long address)
	239	{
	240	pte_t *pte;
	241	if (mem_init_done) {
	242	pte = (pte_t *)__get_free_page(GFP_KERNEL \|
	243	__GFP_REPEAT \| __GFP_ZERO);
	244	} else {
	245	pte = (pte_t *)early_get_page();
	246	if (pte)
	247	clear_page(pte);
	248	}
	249	return pte;
	250	}
41938761 MS	251
	252	void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
	253	{
	254	unsigned long address = __fix_to_virt(idx);
	255
	256	if (idx >= __end_of_fixed_addresses)
	257	BUG();
	258
	259	map_page(address, phys, pgprot_val(flags));
	260	}