| Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 1 | /* |
| 2 | * highmem.h: virtual kernel memory mappings for high memory |
| 3 | * |
| 4 | * Used in CONFIG_HIGHMEM systems for memory pages which |
| 5 | * are not addressable by direct kernel virtual addresses. |
| 6 | * |
| 7 | * Copyright (C) 1999 Gerhard Wichert, Siemens AG |
| 8 | * Gerhard.Wichert@pdb.siemens.de |
| 9 | * |
| 10 | * |
| 11 | * Redesigned the x86 32-bit VM architecture to deal with |
| 12 | * up to 16 Terabyte physical memory. With current x86 CPUs |
| 13 | * we now support up to 64 Gigabytes physical RAM. |
| 14 | * |
| 15 | * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com> |
| 16 | */ |
| 17 | #ifndef _ASM_HIGHMEM_H |
| 18 | #define _ASM_HIGHMEM_H |
| 19 | |
| 20 | #ifdef __KERNEL__ |
| 21 | |
| 22 | #include <linux/interrupt.h> |
| 23 | #include <linux/uaccess.h> |
| 24 | #include <asm/kmap_types.h> |
| 25 | |
| 26 | /* undef for production */ |
| 27 | #define HIGHMEM_DEBUG 1 |
| 28 | |
| 29 | /* declarations for highmem.c */ |
| 30 | extern unsigned long highstart_pfn, highend_pfn; |
| 31 | |
| 32 | extern pte_t *pkmap_page_table; |
| 33 | |
| 34 | /* |
| 35 | * Right now we initialize only a single pte table. It can be extended |
| 36 | * easily, subsequent pte tables have to be allocated in one physical |
| 37 | * chunk of RAM. |
| 38 | */ |
| 39 | #define LAST_PKMAP 1024 |
| 40 | #define LAST_PKMAP_MASK (LAST_PKMAP-1) |
| 41 | #define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) |
| 42 | #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) |
| 43 | |
| 44 | extern void * kmap_high(struct page *page); |
| 45 | extern void kunmap_high(struct page *page); |
| 46 | |
| 47 | extern void *kmap(struct page *page); |
| 48 | extern void kunmap(struct page *page); |
| 49 | extern void *kmap_atomic(struct page *page); |
| 50 | extern void __kunmap_atomic(void *kvaddr); |
| 51 | extern void *kmap_atomic_pfn(unsigned long pfn); |
| 52 | |
| 53 | #define flush_cache_kmaps() flush_cache_all() |
| 54 | |
| 55 | extern void kmap_init(void); |
| 56 | |
| 57 | #define kmap_prot PAGE_KERNEL |
| 58 | |
| 59 | #endif /* __KERNEL__ */ |
| 60 | |
| 61 | #endif /* _ASM_HIGHMEM_H */ |