[net-next-2.6.git] / arch / arm / mm / highmem.c

/*
 * arch/arm/mm/highmem.c -- ARM highmem support
 *
 * Author:	Nicolas Pitre
 * Created:	september 8, 2008
 * Copyright:	Marvell Semiconductors Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/highmem.h>
#include <linux/interrupt.h>
#include <asm/fixmap.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include "mm.h"

void *kmap(struct page *page)
{
	might_sleep();
	if (!PageHighMem(page))
		return page_address(page);
	return kmap_high(page);
}
EXPORT_SYMBOL(kmap);

void kunmap(struct page *page)
{
	BUG_ON(in_interrupt());
	if (!PageHighMem(page))
		return;
	kunmap_high(page);
}
EXPORT_SYMBOL(kunmap);

void *kmap_atomic(struct page *page, enum km_type type)
{
	unsigned int idx;
	unsigned long vaddr;

	pagefault_disable();
	if (!PageHighMem(page))
		return page_address(page);

	idx = type + KM_TYPE_NR * smp_processor_id();
	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
#ifdef CONFIG_DEBUG_HIGHMEM
	/*
	 * With debugging enabled, kunmap_atomic forces that entry to 0.
	 * Make sure it was indeed properly unmapped.
	 */
	BUG_ON(!pte_none(*(TOP_PTE(vaddr))));
#endif
	set_pte_ext(TOP_PTE(vaddr), mk_pte(page, kmap_prot), 0);
	/*
	 * When debugging is off, kunmap_atomic leaves the previous mapping
	 * in place, so this TLB flush ensures the TLB is updated with the
	 * new mapping.
	 */
	local_flush_tlb_kernel_page(vaddr);

	return (void *)vaddr;
}
EXPORT_SYMBOL(kmap_atomic);

void kunmap_atomic(void *kvaddr, enum km_type type)
{
	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
	unsigned int idx = type + KM_TYPE_NR * smp_processor_id();

	if (kvaddr >= (void *)FIXADDR_START) {
		__cpuc_flush_dcache_page((void *)vaddr);
#ifdef CONFIG_DEBUG_HIGHMEM
		BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
		set_pte_ext(TOP_PTE(vaddr), __pte(0), 0);
		local_flush_tlb_kernel_page(vaddr);
#else
		(void) idx;  /* to kill a warning */
#endif
	}
	pagefault_enable();
}
EXPORT_SYMBOL(kunmap_atomic);

void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
{
	unsigned int idx;
	unsigned long vaddr;

	pagefault_disable();

	idx = type + KM_TYPE_NR * smp_processor_id();
	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
#ifdef CONFIG_DEBUG_HIGHMEM
	BUG_ON(!pte_none(*(TOP_PTE(vaddr))));
#endif
	set_pte_ext(TOP_PTE(vaddr), pfn_pte(pfn, kmap_prot), 0);
	local_flush_tlb_kernel_page(vaddr);

	return (void *)vaddr;
}

struct page *kmap_atomic_to_page(const void *ptr)
{
	unsigned long vaddr = (unsigned long)ptr;
	pte_t *pte;

	if (vaddr < FIXADDR_START)
		return virt_to_page(ptr);

	pte = TOP_PTE(vaddr);
	return pte_page(*pte);
}
Commit	Line	Data
d73cd428 NP	1	/*
	2	* arch/arm/mm/highmem.c -- ARM highmem support
	3	*
	4	* Author: Nicolas Pitre
	5	* Created: september 8, 2008
	6	* Copyright: Marvell Semiconductors Inc.
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12
	13	#include <linux/module.h>
	14	#include <linux/highmem.h>
	15	#include <linux/interrupt.h>
	16	#include <asm/fixmap.h>
	17	#include <asm/cacheflush.h>
	18	#include <asm/tlbflush.h>
	19	#include "mm.h"
	20
	21	void kmap(struct page page)
	22	{
	23	might_sleep();
	24	if (!PageHighMem(page))
	25	return page_address(page);
	26	return kmap_high(page);
	27	}
	28	EXPORT_SYMBOL(kmap);
	29
	30	void kunmap(struct page *page)
	31	{
	32	BUG_ON(in_interrupt());
	33	if (!PageHighMem(page))
	34	return;
	35	kunmap_high(page);
	36	}
	37	EXPORT_SYMBOL(kunmap);
	38
	39	void kmap_atomic(struct page page, enum km_type type)
	40	{
	41	unsigned int idx;
	42	unsigned long vaddr;
	43
	44	pagefault_disable();
	45	if (!PageHighMem(page))
	46	return page_address(page);
	47
	48	idx = type + KM_TYPE_NR * smp_processor_id();
	49	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
	50	#ifdef CONFIG_DEBUG_HIGHMEM
	51	/*
	52	* With debugging enabled, kunmap_atomic forces that entry to 0.
	53	* Make sure it was indeed properly unmapped.
	54	*/
	55	BUG_ON(!pte_none(*(TOP_PTE(vaddr))));
	56	#endif
	57	set_pte_ext(TOP_PTE(vaddr), mk_pte(page, kmap_prot), 0);
	58	/*
	59	* When debugging is off, kunmap_atomic leaves the previous mapping
	60	* in place, so this TLB flush ensures the TLB is updated with the
	61	* new mapping.
	62	*/
	63	local_flush_tlb_kernel_page(vaddr);
	64
65	return (void *)vaddr;
66	}
67	EXPORT_SYMBOL(kmap_atomic);
68
69	void kunmap_atomic(void *kvaddr, enum km_type type)
70	{
71	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
72	unsigned int idx = type + KM_TYPE_NR * smp_processor_id();
73
74	if (kvaddr >= (void *)FIXADDR_START) {
75	__cpuc_flush_dcache_page((void *)vaddr);
76	#ifdef CONFIG_DEBUG_HIGHMEM
77	BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
78	set_pte_ext(TOP_PTE(vaddr), __pte(0), 0);
79	local_flush_tlb_kernel_page(vaddr);
80	#else
81	(void) idx; /* to kill a warning */
82	#endif
83	}
84	pagefault_enable();
85	}
86	EXPORT_SYMBOL(kunmap_atomic);
87
88	void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
89	{
90	unsigned int idx;
91	unsigned long vaddr;
92
93	pagefault_disable();
94
95	idx = type + KM_TYPE_NR * smp_processor_id();
96	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
97	#ifdef CONFIG_DEBUG_HIGHMEM
98	BUG_ON(!pte_none(*(TOP_PTE(vaddr))));
99	#endif
100	set_pte_ext(TOP_PTE(vaddr), pfn_pte(pfn, kmap_prot), 0);
101	local_flush_tlb_kernel_page(vaddr);
102
103	return (void *)vaddr;
104	}
105
106	struct page kmap_atomic_to_page(const void ptr)
107	{
108	unsigned long vaddr = (unsigned long)ptr;
109	pte_t *pte;
110
111	if (vaddr < FIXADDR_START)
112	return virt_to_page(ptr);
113
114	pte = TOP_PTE(vaddr);
115	return pte_page(*pte);
116	}