projects / mirror_ubuntu-artful-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| 2f2f371f MS |
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/init.h> | |
| 23 | #include <linux/interrupt.h> | |
| 24 | #include <linux/uaccess.h> | |
| 25 | #include <asm/fixmap.h> | |
| 26 | ||
| 27 | extern pte_t *kmap_pte; | |
| 28 | extern pgprot_t kmap_prot; | |
| 29 | extern pte_t *pkmap_page_table; | |
| 30 | ||
| 31 | /* | |
| 32 | * Right now we initialize only a single pte table. It can be extended | |
| 33 | * easily, subsequent pte tables have to be allocated in one physical | |
| 34 | * chunk of RAM. | |
| 35 | */ | |
| 36 | /* | |
| 37 | * We use one full pte table with 4K pages. And with 16K/64K/256K pages pte | |
| 38 | * table covers enough memory (32MB/512MB/2GB resp.), so that both FIXMAP | |
| 39 | * and PKMAP can be placed in a single pte table. We use 512 pages for PKMAP | |
| 40 | * in case of 16K/64K/256K page sizes. | |
| 41 | */ | |
| 42 | ||
| 43 | #define PKMAP_ORDER PTE_SHIFT | |
| 44 | #define LAST_PKMAP (1 << PKMAP_ORDER) | |
| 45 | ||
| 46 | #define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE * (LAST_PKMAP + 1)) \ | |
| 47 | & PMD_MASK) | |
| 48 | ||
| 49 | #define LAST_PKMAP_MASK (LAST_PKMAP - 1) | |
| 50 | #define PKMAP_NR(virt) ((virt - PKMAP_BASE) >> PAGE_SHIFT) | |
| 51 | #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) | |
| 52 | ||
| 53 | extern void *kmap_high(struct page *page); | |
| 54 | extern void kunmap_high(struct page *page); | |
| 55 | extern void *kmap_atomic_prot(struct page *page, pgprot_t prot); | |
| 56 | extern void __kunmap_atomic(void *kvaddr); | |
| 57 | ||
| 58 | static inline void *kmap(struct page *page) | |
| 59 | { | |
| 60 | might_sleep(); | |
| 61 | if (!PageHighMem(page)) | |
| 62 | return page_address(page); | |
| 63 | return kmap_high(page); | |
| 64 | } | |
| 65 | ||
| 66 | static inline void kunmap(struct page *page) | |
| 67 | { | |
| 68 | BUG_ON(in_interrupt()); | |
| 69 | if (!PageHighMem(page)) | |
| 70 | return; | |
| 71 | kunmap_high(page); | |
| 72 | } | |
| 73 | ||
| ffed2b4f | 74 | static inline void *kmap_atomic(struct page *page) |
| 2f2f371f MS |
75 | { |
| 76 | return kmap_atomic_prot(page, kmap_prot); | |
| 77 | } | |
| 78 | ||
| 2f2f371f MS |
79 | #define flush_cache_kmaps() { flush_icache(); flush_dcache(); } |
| 80 | ||
| 81 | #endif /* __KERNEL__ */ | |
| 82 | ||
| 83 | #endif /* _ASM_HIGHMEM_H */ |