[mirror_ubuntu-focal-kernel.git] / arch / mn10300 / include / asm / highmem.h

/* MN10300 Virtual kernel memory mappings for high memory
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 * - Derived from include/asm-i386/highmem.h
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */
#ifndef _ASM_HIGHMEM_H
#define _ASM_HIGHMEM_H

#ifdef __KERNEL__

#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/highmem.h>
#include <asm/kmap_types.h>
#include <asm/pgtable.h>

/* undef for production */
#undef HIGHMEM_DEBUG

/* declarations for highmem.c */
extern unsigned long highstart_pfn, highend_pfn;

extern pte_t *kmap_pte;
extern pgprot_t kmap_prot;
extern pte_t *pkmap_page_table;

extern void __init kmap_init(void);

/*
 * Right now we initialize only a single pte table. It can be extended
 * easily, subsequent pte tables have to be allocated in one physical
 * chunk of RAM.
 */
#define PKMAP_BASE	0xfe000000UL
#define LAST_PKMAP	1024
#define LAST_PKMAP_MASK (LAST_PKMAP - 1)
#define PKMAP_NR(virt)  ((virt - PKMAP_BASE) >> PAGE_SHIFT)
#define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))

extern unsigned long kmap_high(struct page *page);
extern void kunmap_high(struct page *page);

static inline unsigned long kmap(struct page *page)
{
	if (in_interrupt())
		BUG();
	if (page < highmem_start_page)
		return page_address(page);
	return kmap_high(page);
}

static inline void kunmap(struct page *page)
{
	if (in_interrupt())
		BUG();
	if (page < highmem_start_page)
		return;
	kunmap_high(page);
}

/*
 * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
 * gives a more generic (and caching) interface. But kmap_atomic can
 * be used in IRQ contexts, so in some (very limited) cases we need
 * it.
 */
static inline void *kmap_atomic(struct page *page)
{
	unsigned long vaddr;
	int idx, type;

	preempt_disable();
	pagefault_disable();
	if (page < highmem_start_page)
		return page_address(page);

	type = kmap_atomic_idx_push();
	idx = type + KM_TYPE_NR * smp_processor_id();
	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
#if HIGHMEM_DEBUG
	if (!pte_none(*(kmap_pte - idx)))
		BUG();
#endif
	set_pte(kmap_pte - idx, mk_pte(page, kmap_prot));
	local_flush_tlb_one(vaddr);

	return (void *)vaddr;
}

static inline void __kunmap_atomic(unsigned long vaddr)
{
	int type;

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

	type = kmap_atomic_idx();

#if HIGHMEM_DEBUG
	{
		unsigned int idx;
		idx = type + KM_TYPE_NR * smp_processor_id();

		if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx))
			BUG();

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

	kmap_atomic_idx_pop();
	pagefault_enable();
	preempt_enable();
}
#endif /* __KERNEL__ */

#endif /* _ASM_HIGHMEM_H */
Commit	Line	Data
b920de1b DH	1	/* MN10300 Virtual kernel memory mappings for high memory
	2	*
	3	* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
	4	* Written by David Howells (dhowells@redhat.com)
	5	* - Derived from include/asm-i386/highmem.h
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public Licence
	9	* as published by the Free Software Foundation; either version
	10	* 2 of the Licence, or (at your option) any later version.
	11	*/
	12	#ifndef _ASM_HIGHMEM_H
	13	#define _ASM_HIGHMEM_H
	14
	15	#ifdef __KERNEL__
	16
	17	#include <linux/init.h>
	18	#include <linux/interrupt.h>
7ca43e75	19	#include <linux/highmem.h>
b920de1b DH	20	#include <asm/kmap_types.h>
	21	#include <asm/pgtable.h>
	22
	23	/* undef for production */
	24	#undef HIGHMEM_DEBUG
	25
	26	/* declarations for highmem.c */
	27	extern unsigned long highstart_pfn, highend_pfn;
	28
	29	extern pte_t *kmap_pte;
	30	extern pgprot_t kmap_prot;
	31	extern pte_t *pkmap_page_table;
	32
	33	extern void __init kmap_init(void);
	34
	35	/*
	36	* Right now we initialize only a single pte table. It can be extended
	37	* easily, subsequent pte tables have to be allocated in one physical
	38	* chunk of RAM.
	39	*/
	40	#define PKMAP_BASE 0xfe000000UL
	41	#define LAST_PKMAP 1024
	42	#define LAST_PKMAP_MASK (LAST_PKMAP - 1)
	43	#define PKMAP_NR(virt) ((virt - PKMAP_BASE) >> PAGE_SHIFT)
	44	#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
	45
21534301 HH	46	extern unsigned long kmap_high(struct page *page);
21534301 HH	47	extern void kunmap_high(struct page *page);
b920de1b DH	48
	49	static inline unsigned long kmap(struct page *page)
	50	{
	51	if (in_interrupt())
	52	BUG();
	53	if (page < highmem_start_page)
	54	return page_address(page);
	55	return kmap_high(page);
	56	}
	57
	58	static inline void kunmap(struct page *page)
	59	{
	60	if (in_interrupt())
	61	BUG();
	62	if (page < highmem_start_page)
	63	return;
	64	kunmap_high(page);
	65	}
	66
	67	/*
	68	* The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
	69	* gives a more generic (and caching) interface. But kmap_atomic can
	70	* be used in IRQ contexts, so in some (very limited) cases we need
	71	* it.
	72	*/
3ef120a4	73	static inline void kmap_atomic(struct page page)
b920de1b	74	{
b920de1b	75	unsigned long vaddr;
3e4d3af5	76	int idx, type;
b920de1b	77
2cb7c9cb	78	preempt_disable();
3e4d3af5	79	pagefault_disable();
b920de1b DH	80	if (page < highmem_start_page)
	81	return page_address(page);
	82
3e4d3af5	83	type = kmap_atomic_idx_push();
b920de1b DH	84	idx = type + KM_TYPE_NR * smp_processor_id();
	85	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
	86	#if HIGHMEM_DEBUG
	87	if (!pte_none(*(kmap_pte - idx)))
	88	BUG();
	89	#endif
	90	set_pte(kmap_pte - idx, mk_pte(page, kmap_prot));
492e6751	91	local_flush_tlb_one(vaddr);
b920de1b	92
3ef120a4	93	return (void *)vaddr;
b920de1b DH	94	}
b920de1b DH	95
3e4d3af5	96	static inline void __kunmap_atomic(unsigned long vaddr)
b920de1b	97	{
3e4d3af5	98	int type;
b920de1b	99
3e4d3af5 PZ	100	if (vaddr < FIXADDR_START) { /* FIXME */
3e4d3af5 PZ	101	pagefault_enable();
2cb7c9cb	102	preempt_enable();
b920de1b	103	return;
3e4d3af5	104	}
b920de1b	105
20273941	106	type = kmap_atomic_idx();
b920de1b	107
3e4d3af5 PZ	108	#if HIGHMEM_DEBUG
	109	{
	110	unsigned int idx;
	111	idx = type + KM_TYPE_NR * smp_processor_id();
	112
	113	if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx))
	114	BUG();
	115
	116	/*
	117	* force other mappings to Oops if they'll try to access
	118	* this pte without first remap it
	119	*/
	120	pte_clear(kmap_pte - idx);
492e6751	121	local_flush_tlb_one(vaddr);
3e4d3af5	122	}
b920de1b	123	#endif
20273941 PZ	124
20273941 PZ	125	kmap_atomic_idx_pop();
3e4d3af5	126	pagefault_enable();
2cb7c9cb	127	preempt_enable();
b920de1b	128	}
b920de1b DH	129	#endif /* __KERNEL__ */
	130
	131	#endif /* _ASM_HIGHMEM_H */