[linux-2.6-block.git] / arch / mips / mm / highmem.c

#include <linux/module.h>
#include <linux/highmem.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <asm/fixmap.h>
#include <asm/tlbflush.h>

static pte_t *kmap_pte;

unsigned long highstart_pfn, highend_pfn;

void *__kmap(struct page *page)
{
	void *addr;

	might_sleep();
	if (!PageHighMem(page))
		return page_address(page);
	addr = kmap_high(page);
	flush_tlb_one((unsigned long)addr);

	return addr;
}
EXPORT_SYMBOL(__kmap);

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

/*
 * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
 * no global lock is needed and because the kmap code must perform a global TLB
 * invalidation when the kmap pool wraps.
 *
 * However when holding an atomic kmap is is not legal to sleep, so atomic
 * kmaps are appropriate for short, tight code paths only.
 */

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

	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
	pagefault_disable();
	if (!PageHighMem(page))
		return page_address(page);

	debug_kmap_atomic(type);
	idx = type + KM_TYPE_NR*smp_processor_id();
	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
#ifdef CONFIG_DEBUG_HIGHMEM
	BUG_ON(!pte_none(*(kmap_pte - idx)));
#endif
	set_pte(kmap_pte-idx, mk_pte(page, PAGE_KERNEL));
	local_flush_tlb_one((unsigned long)vaddr);

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

void __kunmap_atomic(void *kvaddr, enum km_type type)
{
#ifdef CONFIG_DEBUG_HIGHMEM
	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
	enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();

	if (vaddr < FIXADDR_START) { // FIXME
		pagefault_enable();
		return;
	}

	BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));

	/*
	 * force other mappings to Oops if they'll try to access
	 * this pte without first remap it
	 */
	pte_clear(&init_mm, vaddr, kmap_pte-idx);
	local_flush_tlb_one(vaddr);
#endif

	pagefault_enable();
}
EXPORT_SYMBOL(__kunmap_atomic);

/*
 * This is the same as kmap_atomic() but can map memory that doesn't
 * have a struct page associated with it.
 */
void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
{
	enum fixed_addresses idx;
	unsigned long vaddr;

	pagefault_disable();

	debug_kmap_atomic(type);
	idx = type + KM_TYPE_NR*smp_processor_id();
	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
	set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
	flush_tlb_one(vaddr);

	return (void*) vaddr;
}

struct page *__kmap_atomic_to_page(void *ptr)
{
	unsigned long idx, vaddr = (unsigned long)ptr;
	pte_t *pte;

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

	idx = virt_to_fix(vaddr);
	pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
	return pte_page(*pte);
}

void __init kmap_init(void)
{
	unsigned long kmap_vstart;

	/* cache the first kmap pte */
	kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
	kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
}
Commit	Line	Data
1da177e4 LT	1	#include <linux/module.h>
1da177e4 LT	2	#include <linux/highmem.h>
52ab320a	3	#include <linux/sched.h>
631330f5	4	#include <linux/smp.h>
bb86bf28	5	#include <asm/fixmap.h>
1da177e4 LT	6	#include <asm/tlbflush.h>
1da177e4 LT	7
bb86bf28 RB	8	static pte_t *kmap_pte;
	9
	10	unsigned long highstart_pfn, highend_pfn;
	11
1da177e4 LT	12	void __kmap(struct page page)
	13	{
	14	void *addr;
	15
	16	might_sleep();
	17	if (!PageHighMem(page))
	18	return page_address(page);
	19	addr = kmap_high(page);
	20	flush_tlb_one((unsigned long)addr);
	21
	22	return addr;
	23	}
bb86bf28	24	EXPORT_SYMBOL(__kmap);
1da177e4 LT	25
	26	void __kunmap(struct page *page)
	27	{
b72b7092	28	BUG_ON(in_interrupt());
1da177e4 LT	29	if (!PageHighMem(page))
	30	return;
	31	kunmap_high(page);
	32	}
bb86bf28	33	EXPORT_SYMBOL(__kunmap);
1da177e4 LT	34
	35	/*
	36	* kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
	37	* no global lock is needed and because the kmap code must perform a global TLB
	38	* invalidation when the kmap pool wraps.
	39	*
	40	* However when holding an atomic kmap is is not legal to sleep, so atomic
	41	* kmaps are appropriate for short, tight code paths only.
	42	*/
	43
	44	void __kmap_atomic(struct page page, enum km_type type)
	45	{
	46	enum fixed_addresses idx;
	47	unsigned long vaddr;
	48
	49	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
a866374a	50	pagefault_disable();
1da177e4 LT	51	if (!PageHighMem(page))
	52	return page_address(page);
	53
7ca43e75	54	debug_kmap_atomic(type);
1da177e4 LT	55	idx = type + KM_TYPE_NR*smp_processor_id();
	56	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
	57	#ifdef CONFIG_DEBUG_HIGHMEM
b72b7092	58	BUG_ON(!pte_none(*(kmap_pte - idx)));
1da177e4	59	#endif
bb86bf28	60	set_pte(kmap_pte-idx, mk_pte(page, PAGE_KERNEL));
1da177e4 LT	61	local_flush_tlb_one((unsigned long)vaddr);
	62
	63	return (void*) vaddr;
	64	}
bb86bf28	65	EXPORT_SYMBOL(__kmap_atomic);
1da177e4 LT	66
	67	void __kunmap_atomic(void *kvaddr, enum km_type type)
	68	{
	69	#ifdef CONFIG_DEBUG_HIGHMEM
	70	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
	71	enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
	72
	73	if (vaddr < FIXADDR_START) { // FIXME
a866374a	74	pagefault_enable();
1da177e4 LT	75	return;
	76	}
	77
b72b7092	78	BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
1da177e4 LT	79
	80	/*
	81	* force other mappings to Oops if they'll try to access
	82	* this pte without first remap it
	83	*/
	84	pte_clear(&init_mm, vaddr, kmap_pte-idx);
	85	local_flush_tlb_one(vaddr);
	86	#endif
	87
a866374a	88	pagefault_enable();
1da177e4	89	}
bb86bf28	90	EXPORT_SYMBOL(__kunmap_atomic);
1da177e4	91
60080265 RB	92	/*
	93	* This is the same as kmap_atomic() but can map memory that doesn't
	94	* have a struct page associated with it.
	95	*/
	96	void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
	97	{
	98	enum fixed_addresses idx;
	99	unsigned long vaddr;
	100
a866374a	101	pagefault_disable();
60080265	102
7ca43e75	103	debug_kmap_atomic(type);
60080265 RB	104	idx = type + KM_TYPE_NR*smp_processor_id();
60080265 RB	105	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
bb86bf28	106	set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL));
60080265 RB	107	flush_tlb_one(vaddr);
	108
	109	return (void*) vaddr;
	110	}
	111
1da177e4 LT	112	struct page __kmap_atomic_to_page(void ptr)
	113	{
	114	unsigned long idx, vaddr = (unsigned long)ptr;
	115	pte_t *pte;
	116
	117	if (vaddr < FIXADDR_START)
	118	return virt_to_page(ptr);
	119
	120	idx = virt_to_fix(vaddr);
	121	pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
	122	return pte_page(*pte);
	123	}
	124
bb86bf28 RB	125	void __init kmap_init(void)
	126	{
	127	unsigned long kmap_vstart;
	128
	129	/* cache the first kmap pte */
	130	kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
	131	kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
	132	}