1 /* SPDX-License-Identifier: GPL-2.0 */ 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 Terabyte 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_X86_HIGHMEM_H 20 #define _ASM_X86_HIGHMEM_H 21 22 #ifdef __KERNEL__ 23 24 #include <linux/interrupt.h> 25 #include <linux/threads.h> 26 #include <asm/tlbflush.h> 27 #include <asm/paravirt.h> 28 #include <asm/fixmap.h> 29 30 /* declarations for highmem.c */ 31 extern unsigned long highstart_pfn, highend_pfn; 32 33 /* 34 * Right now we initialize only a single pte table. It can be extended 35 * easily, subsequent pte tables have to be allocated in one physical 36 * chunk of RAM. 37 */ 38 /* 39 * Ordering is: 40 * 41 * high memory on: high_memory off: 42 * FIXADDR_TOP FIXADDR_TOP 43 * fixed addresses fixed addresses 44 * FIXADDR_START FIXADDR_START 45 * temp fixed addresses/persistent kmap area VMALLOC_END 46 * PKMAP_BASE temp fixed addresses/vmalloc area 47 * VMALLOC_END VMALLOC_START 48 * vmalloc area high_memory 49 * VMALLOC_START 50 * high_memory 51 * 52 * The temp fixed area is only used during boot for early_ioremap(), and 53 * it is unused when the ioremap() is functional. vmalloc/pkmap area become 54 * available after early boot so the temp fixed area is available for re-use. 55 */ 56 #define LAST_PKMAP_MASK (LAST_PKMAP-1) 57 #define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) 58 #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) 59 60 #define flush_cache_kmaps() do { } while (0) 61 62 #define arch_kmap_local_post_map(vaddr, pteval) \ 63 arch_flush_lazy_mmu_mode() 64 65 #define arch_kmap_local_post_unmap(vaddr) \ 66 do { \ 67 flush_tlb_one_kernel((vaddr)); \ 68 arch_flush_lazy_mmu_mode(); \ 69 } while (0) 70 71 extern void add_highpages_with_active_regions(int nid, unsigned long start_pfn, 72 unsigned long end_pfn); 73 74 #endif /* __KERNEL__ */ 75 76 #endif /* _ASM_X86_HIGHMEM_H */ 77