[linux-block.git] / arch / sparc / include / asm / highmem.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * highmem.h: virtual kernel memory mappings for high memory
 *
 * Used in CONFIG_HIGHMEM systems for memory pages which
 * are not addressable by direct kernel virtual addresses.
 *
 * Copyright (C) 1999 Gerhard Wichert, Siemens AG
 *		      Gerhard.Wichert@pdb.siemens.de
 *
 *
 * Redesigned the x86 32-bit VM architecture to deal with 
 * up to 16 Terrabyte physical memory. With current x86 CPUs
 * we now support up to 64 Gigabytes physical RAM.
 *
 * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
 */

#ifndef _ASM_HIGHMEM_H
#define _ASM_HIGHMEM_H

#ifdef __KERNEL__

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

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

extern pgprot_t kmap_prot;
extern pte_t *pkmap_page_table;

void kmap_init(void) __init;

/*
 * 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.  Currently the simplest way to do this is to align the
 * pkmap region on a pagetable boundary (4MB).
 */
#define LAST_PKMAP 1024
#define PKMAP_SIZE (LAST_PKMAP << PAGE_SHIFT)
#define PKMAP_BASE PMD_ALIGN(SRMMU_NOCACHE_VADDR + (SRMMU_MAX_NOCACHE_PAGES << PAGE_SHIFT))

#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))

#define PKMAP_END (PKMAP_ADDR(LAST_PKMAP))

void *kmap_high(struct page *page);
void kunmap_high(struct page *page);

static inline void *kmap(struct page *page)
{
	BUG_ON(in_interrupt());
	if (!PageHighMem(page))
		return page_address(page);
	return kmap_high(page);
}

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

void *kmap_atomic(struct page *page);
void __kunmap_atomic(void *kvaddr);

#define flush_cache_kmaps()	flush_cache_all()

#endif /* __KERNEL__ */

#endif /* _ASM_HIGHMEM_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
1da177e4 LT	2	/*
	3	* highmem.h: virtual kernel memory mappings for high memory
	4	*
	5	* Used in CONFIG_HIGHMEM systems for memory pages which
	6	* are not addressable by direct kernel virtual addresses.
	7	*
	8	* Copyright (C) 1999 Gerhard Wichert, Siemens AG
	9	* Gerhard.Wichert@pdb.siemens.de
	10	*
	11	*
	12	* Redesigned the x86 32-bit VM architecture to deal with
	13	* up to 16 Terrabyte physical memory. With current x86 CPUs
	14	* we now support up to 64 Gigabytes physical RAM.
	15	*
	16	* Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
	17	*/
	18
	19	#ifndef _ASM_HIGHMEM_H
	20	#define _ASM_HIGHMEM_H
	21
	22	#ifdef __KERNEL__
	23
	24	#include <linux/interrupt.h>
1da177e4 LT	25	#include <asm/vaddrs.h>
	26	#include <asm/kmap_types.h>
	27	#include <asm/pgtable.h>
	28
	29	/* declarations for highmem.c */
	30	extern unsigned long highstart_pfn, highend_pfn;
	31
1da177e4 LT	32	extern pgprot_t kmap_prot;
	33	extern pte_t *pkmap_page_table;
	34
f05a6865	35	void kmap_init(void) __init;
1da177e4 LT	36
	37	/*
	38	* Right now we initialize only a single pte table. It can be extended
	39	* easily, subsequent pte tables have to be allocated in one physical
	40	* chunk of RAM. Currently the simplest way to do this is to align the
	41	* pkmap region on a pagetable boundary (4MB).
	42	*/
	43	#define LAST_PKMAP 1024
	44	#define PKMAP_SIZE (LAST_PKMAP << PAGE_SHIFT)
	45	#define PKMAP_BASE PMD_ALIGN(SRMMU_NOCACHE_VADDR + (SRMMU_MAX_NOCACHE_PAGES << PAGE_SHIFT))
	46
	47	#define LAST_PKMAP_MASK (LAST_PKMAP - 1)
	48	#define PKMAP_NR(virt) ((virt - PKMAP_BASE) >> PAGE_SHIFT)
	49	#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
	50
	51	#define PKMAP_END (PKMAP_ADDR(LAST_PKMAP))
	52
f05a6865 SR	53	void kmap_high(struct page page);
f05a6865 SR	54	void kunmap_high(struct page *page);
1da177e4 LT	55
	56	static inline void kmap(struct page page)
	57	{
	58	BUG_ON(in_interrupt());
	59	if (!PageHighMem(page))
	60	return page_address(page);
	61	return kmap_high(page);
	62	}
	63
	64	static inline void kunmap(struct page *page)
	65	{
	66	BUG_ON(in_interrupt());
	67	if (!PageHighMem(page))
	68	return;
	69	kunmap_high(page);
	70	}
	71
f05a6865 SR	72	void kmap_atomic(struct page page);
f05a6865 SR	73	void __kunmap_atomic(void *kvaddr);
1da177e4 LT	74
	75	#define flush_cache_kmaps() flush_cache_all()
	76
	77	#endif /* __KERNEL__ */
	78
	79	#endif /* _ASM_HIGHMEM_H */