| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | // Copyright (C) 2005-2017 Andes Technology Corporation |
| 3 | |
| 4 | #ifndef _ASM_HIGHMEM_H |
| 5 | #define _ASM_HIGHMEM_H |
| 6 | |
| 7 | #include <asm/proc-fns.h> |
| 8 | #include <asm/kmap_types.h> |
| 9 | #include <asm/fixmap.h> |
| 10 | #include <asm/pgtable.h> |
| 11 | |
| 12 | /* |
| 13 | * Right now we initialize only a single pte table. It can be extended |
| 14 | * easily, subsequent pte tables have to be allocated in one physical |
| 15 | * chunk of RAM. |
| 16 | */ |
| 17 | /* |
| 18 | * Ordering is (from lower to higher memory addresses): |
| 19 | * |
| 20 | * high_memory |
| 21 | * Persistent kmap area |
| 22 | * PKMAP_BASE |
| 23 | * fixed_addresses |
| 24 | * FIXADDR_START |
| 25 | * FIXADDR_TOP |
| 26 | * Vmalloc area |
| 27 | * VMALLOC_START |
| 28 | * VMALLOC_END |
| 29 | */ |
| 30 | #define PKMAP_BASE ((FIXADDR_START - PGDIR_SIZE) & (PGDIR_MASK)) |
| 31 | #define LAST_PKMAP PTRS_PER_PTE |
| 32 | #define LAST_PKMAP_MASK (LAST_PKMAP - 1) |
| 33 | #define PKMAP_NR(virt) (((virt) - (PKMAP_BASE)) >> PAGE_SHIFT) |
| 34 | #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) |
| 35 | #define kmap_prot PAGE_KERNEL |
| 36 | |
| 37 | static inline void flush_cache_kmaps(void) |
| 38 | { |
| 39 | cpu_dcache_wbinval_all(); |
| 40 | } |
| 41 | |
| 42 | /* declarations for highmem.c */ |
| 43 | extern unsigned long highstart_pfn, highend_pfn; |
| 44 | |
| 45 | extern pte_t *pkmap_page_table; |
| 46 | |
| 47 | extern void *kmap_high(struct page *page); |
| 48 | extern void kunmap_high(struct page *page); |
| 49 | |
| 50 | extern void kmap_init(void); |
| 51 | |
| 52 | /* |
| 53 | * The following functions are already defined by <linux/highmem.h> |
| 54 | * when CONFIG_HIGHMEM is not set. |
| 55 | */ |
| 56 | #ifdef CONFIG_HIGHMEM |
| 57 | extern void *kmap(struct page *page); |
| 58 | extern void kunmap(struct page *page); |
| 59 | extern void *kmap_atomic(struct page *page); |
| 60 | extern void __kunmap_atomic(void *kvaddr); |
| 61 | extern void *kmap_atomic_pfn(unsigned long pfn); |
| 62 | extern struct page *kmap_atomic_to_page(void *ptr); |
| 63 | #endif |
| 64 | |
| 65 | #endif |