linux/arch/csky/include/asm/highmem.h
Guo Ren 013de2d667 csky: MMU and page table management
This patch adds files related to memory management and here is our
memory-layout:

   Fixmap       : 0xffc02000 – 0xfffff000       (4 MB - 12KB)
   Pkmap        : 0xff800000 – 0xffc00000       (4 MB)
   Vmalloc      : 0xf0200000 – 0xff000000       (238 MB)
   Lowmem       : 0x80000000 – 0xc0000000       (1GB)

abiv1 CPU (CK610) is VIPT cache and it doesn't support highmem.
abiv2 CPUs are all PIPT cache and they could support highmem.

Lowmem is directly mapped by msa0 & msa1 reg, and we needn't setup
memory page table for it.

Link:https://lore.kernel.org/lkml/20180518215548.GH17671@n2100.armlinux.org.uk/
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Cc: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
2018-10-25 23:36:19 +08:00

52 lines
1.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
#ifndef __ASM_CSKY_HIGHMEM_H
#define __ASM_CSKY_HIGHMEM_H
#ifdef __KERNEL__
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/uaccess.h>
#include <asm/kmap_types.h>
#include <asm/cache.h>
/* undef for production */
#define HIGHMEM_DEBUG 1
/* declarations for highmem.c */
extern unsigned long highstart_pfn, highend_pfn;
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.
*/
#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 void *kmap_high(struct page *page);
extern void kunmap_high(struct page *page);
extern void *kmap(struct page *page);
extern void kunmap(struct page *page);
extern void *kmap_atomic(struct page *page);
extern void __kunmap_atomic(void *kvaddr);
extern void *kmap_atomic_pfn(unsigned long pfn);
extern struct page *kmap_atomic_to_page(void *ptr);
#define flush_cache_kmaps() do {} while (0)
extern void kmap_init(void);
#define kmap_prot PAGE_KERNEL
#endif /* __KERNEL__ */
#endif /* __ASM_CSKY_HIGHMEM_H */