[linux-2.6-block.git] / arch / powerpc / include / asm / highmem.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * highmem.h: virtual kernel memory mappings for high memory
 *
 * PowerPC version, stolen from the i386 version.
 *
 * 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/kmap_types.h>
#include <asm/cacheflush.h>
#include <asm/page.h>
#include <asm/fixmap.h>

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

/*
 * 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.
 */
/*
 * We use one full pte table with 4K pages. And with 16K/64K/256K pages pte
 * table covers enough memory (32MB/512MB/2GB resp.), so that both FIXMAP
 * and PKMAP can be placed in a single pte table. We use 512 pages for PKMAP
 * in case of 16K/64K/256K page sizes.
 */
#ifdef CONFIG_PPC_4K_PAGES
#define PKMAP_ORDER	PTE_SHIFT
#else
#define PKMAP_ORDER	9
#endif
#define LAST_PKMAP	(1 << PKMAP_ORDER)
#ifndef CONFIG_PPC_4K_PAGES
#define PKMAP_BASE	(FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1))
#else
#define PKMAP_BASE	((FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK)
#endif
#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 void *kmap_high(struct page *page);
extern void kunmap_high(struct page *page);
extern void *kmap_atomic_prot(struct page *page, pgprot_t prot);
extern void __kunmap_atomic(void *kvaddr);

static inline void *kmap(struct page *page)
{
	might_sleep();
	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);
}

static inline void *kmap_atomic(struct page *page)
{
	return kmap_atomic_prot(page, kmap_prot);
}


#define flush_cache_kmaps()	flush_cache_all()

#endif /* __KERNEL__ */

#endif /* _ASM_HIGHMEM_H */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
33d71d26 KG	2	/*
	3	* highmem.h: virtual kernel memory mappings for high memory
	4	*
	5	* PowerPC version, stolen from the i386 version.
	6	*
	7	* Used in CONFIG_HIGHMEM systems for memory pages which
	8	* are not addressable by direct kernel virtual addresses.
	9	*
	10	* Copyright (C) 1999 Gerhard Wichert, Siemens AG
	11	* Gerhard.Wichert@pdb.siemens.de
	12	*
	13	*
	14	* Redesigned the x86 32-bit VM architecture to deal with
	15	* up to 16 Terrabyte physical memory. With current x86 CPUs
	16	* we now support up to 64 Gigabytes physical RAM.
	17	*
	18	* Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
	19	*/
	20
	21	#ifndef _ASM_HIGHMEM_H
	22	#define _ASM_HIGHMEM_H
	23
	24	#ifdef __KERNEL__
	25
33d71d26 KG	26	#include <linux/interrupt.h>
33d71d26 KG	27	#include <asm/kmap_types.h>
45ef5992	28	#include <asm/cacheflush.h>
33d71d26	29	#include <asm/page.h>
2c419bde	30	#include <asm/fixmap.h>
33d71d26 KG	31
	32	extern pte_t *kmap_pte;
	33	extern pgprot_t kmap_prot;
	34	extern pte_t *pkmap_page_table;
	35
	36	/*
	37	* Right now we initialize only a single pte table. It can be extended
	38	* easily, subsequent pte tables have to be allocated in one physical
	39	* chunk of RAM.
	40	*/
ca9153a3	41	/*
e1240122 YT	42	* We use one full pte table with 4K pages. And with 16K/64K/256K pages pte
	43	* table covers enough memory (32MB/512MB/2GB resp.), so that both FIXMAP
	44	* and PKMAP can be placed in a single pte table. We use 512 pages for PKMAP
	45	* in case of 16K/64K/256K page sizes.
ca9153a3 IY	46	*/
	47	#ifdef CONFIG_PPC_4K_PAGES
	48	#define PKMAP_ORDER PTE_SHIFT
	49	#else
e1240122	50	#define PKMAP_ORDER 9
ca9153a3 IY	51	#endif
	52	#define LAST_PKMAP (1 << PKMAP_ORDER)
	53	#ifndef CONFIG_PPC_4K_PAGES
	54	#define PKMAP_BASE (FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1))
	55	#else
2c419bde	56	#define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK)
ca9153a3 IY	57	#endif
ca9153a3 IY	58	#define LAST_PKMAP_MASK (LAST_PKMAP-1)
33d71d26 KG	59	#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)
	60	#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
	61
33d71d26 KG	62	extern void kmap_high(struct page page);
33d71d26 KG	63	extern void kunmap_high(struct page *page);
3e4d3af5 PZ	64	extern void kmap_atomic_prot(struct page page, pgprot_t prot);
3e4d3af5 PZ	65	extern void __kunmap_atomic(void *kvaddr);
33d71d26 KG	66
	67	static inline void kmap(struct page page)
	68	{
	69	might_sleep();
	70	if (!PageHighMem(page))
	71	return page_address(page);
	72	return kmap_high(page);
	73	}
	74
	75	static inline void kunmap(struct page *page)
	76	{
	77	BUG_ON(in_interrupt());
	78	if (!PageHighMem(page))
	79	return;
	80	kunmap_high(page);
	81	}
	82
a24401bc	83	static inline void kmap_atomic(struct page page)
2c419bde	84	{
3e4d3af5	85	return kmap_atomic_prot(page, kmap_prot);
2c419bde KG	86	}
2c419bde KG	87
850f6ac3	88
33d71d26 KG	89	#define flush_cache_kmaps() flush_cache_all()
	90
	91	#endif /* __KERNEL__ */
	92
	93	#endif /* _ASM_HIGHMEM_H */