arch/powerpc/include/asm/highmem.h

Source file repositories/reference/linux-study-clean/arch/powerpc/include/asm/highmem.h

File Facts

System
Linux kernel
Corpus path
arch/powerpc/include/asm/highmem.h
Extension
.h
Size
2079 bytes
Lines
71
Domain
Architecture Layer
Bucket
arch/powerpc
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef _ASM_HIGHMEM_H
#define _ASM_HIGHMEM_H

#ifdef __KERNEL__

#include <linux/interrupt.h>
#include <asm/cacheflush.h>
#include <asm/page.h>
#include <asm/fixmap.h>

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))

#define flush_cache_kmaps()	flush_cache_all()

#define arch_kmap_local_set_pte(mm, vaddr, ptep, ptev)	\
	__set_pte_at(mm, vaddr, ptep, ptev, 1)
#define arch_kmap_local_post_map(vaddr, pteval)	\
	local_flush_tlb_page(NULL, vaddr)
#define arch_kmap_local_post_unmap(vaddr)	\
	local_flush_tlb_page(NULL, vaddr)

#endif /* __KERNEL__ */

#endif /* _ASM_HIGHMEM_H */

Annotation

Implementation Notes