1*4882a593Smuzhiyun /* SPDX-License-Identifier: GPL-2.0 */ 2*4882a593Smuzhiyun /* 3*4882a593Smuzhiyun * highmem.h: virtual kernel memory mappings for high memory 4*4882a593Smuzhiyun * 5*4882a593Smuzhiyun * Used in CONFIG_HIGHMEM systems for memory pages which 6*4882a593Smuzhiyun * are not addressable by direct kernel virtual addresses. 7*4882a593Smuzhiyun * 8*4882a593Smuzhiyun * Copyright (C) 1999 Gerhard Wichert, Siemens AG 9*4882a593Smuzhiyun * Gerhard.Wichert@pdb.siemens.de 10*4882a593Smuzhiyun * 11*4882a593Smuzhiyun * 12*4882a593Smuzhiyun * Redesigned the x86 32-bit VM architecture to deal with 13*4882a593Smuzhiyun * up to 16 Terrabyte physical memory. With current x86 CPUs 14*4882a593Smuzhiyun * we now support up to 64 Gigabytes physical RAM. 15*4882a593Smuzhiyun * 16*4882a593Smuzhiyun * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com> 17*4882a593Smuzhiyun */ 18*4882a593Smuzhiyun 19*4882a593Smuzhiyun #ifndef _ASM_HIGHMEM_H 20*4882a593Smuzhiyun #define _ASM_HIGHMEM_H 21*4882a593Smuzhiyun 22*4882a593Smuzhiyun #ifdef __KERNEL__ 23*4882a593Smuzhiyun 24*4882a593Smuzhiyun #include <linux/interrupt.h> 25*4882a593Smuzhiyun #include <linux/pgtable.h> 26*4882a593Smuzhiyun #include <asm/vaddrs.h> 27*4882a593Smuzhiyun #include <asm/kmap_types.h> 28*4882a593Smuzhiyun #include <asm/pgtsrmmu.h> 29*4882a593Smuzhiyun 30*4882a593Smuzhiyun /* declarations for highmem.c */ 31*4882a593Smuzhiyun extern unsigned long highstart_pfn, highend_pfn; 32*4882a593Smuzhiyun 33*4882a593Smuzhiyun #define kmap_prot __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE) 34*4882a593Smuzhiyun extern pte_t *pkmap_page_table; 35*4882a593Smuzhiyun 36*4882a593Smuzhiyun void kmap_init(void) __init; 37*4882a593Smuzhiyun 38*4882a593Smuzhiyun /* 39*4882a593Smuzhiyun * Right now we initialize only a single pte table. It can be extended 40*4882a593Smuzhiyun * easily, subsequent pte tables have to be allocated in one physical 41*4882a593Smuzhiyun * chunk of RAM. Currently the simplest way to do this is to align the 42*4882a593Smuzhiyun * pkmap region on a pagetable boundary (4MB). 43*4882a593Smuzhiyun */ 44*4882a593Smuzhiyun #define LAST_PKMAP 1024 45*4882a593Smuzhiyun #define PKMAP_SIZE (LAST_PKMAP << PAGE_SHIFT) 46*4882a593Smuzhiyun #define PKMAP_BASE PMD_ALIGN(SRMMU_NOCACHE_VADDR + (SRMMU_MAX_NOCACHE_PAGES << PAGE_SHIFT)) 47*4882a593Smuzhiyun 48*4882a593Smuzhiyun #define LAST_PKMAP_MASK (LAST_PKMAP - 1) 49*4882a593Smuzhiyun #define PKMAP_NR(virt) ((virt - PKMAP_BASE) >> PAGE_SHIFT) 50*4882a593Smuzhiyun #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) 51*4882a593Smuzhiyun 52*4882a593Smuzhiyun #define PKMAP_END (PKMAP_ADDR(LAST_PKMAP)) 53*4882a593Smuzhiyun 54*4882a593Smuzhiyun #define flush_cache_kmaps() flush_cache_all() 55*4882a593Smuzhiyun 56*4882a593Smuzhiyun #endif /* __KERNEL__ */ 57*4882a593Smuzhiyun 58*4882a593Smuzhiyun #endif /* _ASM_HIGHMEM_H */ 59