projects / mirror_ubuntu-bionic-kernel.git / blame
| Commit | Line | Data |
|---|---|---|
| b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| d73cd428 NP |
2 | #ifndef _ASM_HIGHMEM_H |
| 3 | #define _ASM_HIGHMEM_H | |
| 4 | ||
| 5 | #include <asm/kmap_types.h> | |
| 6 | ||
| 7 | #define PKMAP_BASE (PAGE_OFFSET - PMD_SIZE) | |
| 8 | #define LAST_PKMAP PTRS_PER_PTE | |
| 9 | #define LAST_PKMAP_MASK (LAST_PKMAP - 1) | |
| 10 | #define PKMAP_NR(virt) (((virt) - PKMAP_BASE) >> PAGE_SHIFT) | |
| 11 | #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) | |
| 12 | ||
| 13 | #define kmap_prot PAGE_KERNEL | |
| 14 | ||
| 7e5a69e8 NP |
15 | #define flush_cache_kmaps() \ |
| 16 | do { \ | |
| 17 | if (cache_is_vivt()) \ | |
| 18 | flush_cache_all(); \ | |
| 19 | } while (0) | |
| d73cd428 NP |
20 | |
| 21 | extern pte_t *pkmap_page_table; | |
| a05e54c1 | 22 | extern pte_t *fixmap_page_table; |
| d73cd428 | 23 | |
| aaa50048 NP |
24 | extern void *kmap_high(struct page *page); |
| 25 | extern void kunmap_high(struct page *page); | |
| 26 | ||
| 27 | /* | |
| 28 | * The reason for kmap_high_get() is to ensure that the currently kmap'd | |
| 29 | * page usage count does not decrease to zero while we're using its | |
| 30 | * existing virtual mapping in an atomic context. With a VIVT cache this | |
| 31 | * is essential to do, but with a VIPT cache this is only an optimization | |
| 32 | * so not to pay the price of establishing a second mapping if an existing | |
| 33 | * one can be used. However, on platforms without hardware TLB maintenance | |
| 34 | * broadcast, we simply cannot use ARCH_NEEDS_KMAP_HIGH_GET at all since | |
| 35 | * the locking involved must also disable IRQs which is incompatible with | |
| 36 | * the IPI mechanism used by global TLB operations. | |
| 37 | */ | |
| 43377453 | 38 | #define ARCH_NEEDS_KMAP_HIGH_GET |
| aaa50048 NP |
39 | #if defined(CONFIG_SMP) && defined(CONFIG_CPU_TLB_V6) |
| 40 | #undef ARCH_NEEDS_KMAP_HIGH_GET | |
| 41 | #if defined(CONFIG_HIGHMEM) && defined(CONFIG_CPU_CACHE_VIVT) | |
| 42 | #error "The sum of features in your kernel config cannot be supported together" | |
| 43 | #endif | |
| 44 | #endif | |
| 43377453 | 45 | |
| 93dc6887 CM |
46 | /* |
| 47 | * Needed to be able to broadcast the TLB invalidation for kmap. | |
| 48 | */ | |
| 49 | #ifdef CONFIG_ARM_ERRATA_798181 | |
| 50 | #undef ARCH_NEEDS_KMAP_HIGH_GET | |
| 51 | #endif | |
| 52 | ||
| aaa50048 | 53 | #ifdef ARCH_NEEDS_KMAP_HIGH_GET |
| 43377453 | 54 | extern void *kmap_high_get(struct page *page); |
| aaa50048 NP |
55 | #else |
| 56 | static inline void *kmap_high_get(struct page *page) | |
| 57 | { | |
| 58 | return NULL; | |
| 59 | } | |
| 60 | #endif | |
| d73cd428 | 61 | |
| 7e5a69e8 NP |
62 | /* |
| 63 | * The following functions are already defined by <linux/highmem.h> | |
| 64 | * when CONFIG_HIGHMEM is not set. | |
| 65 | */ | |
| 66 | #ifdef CONFIG_HIGHMEM | |
| d73cd428 NP |
67 | extern void *kmap(struct page *page); |
| 68 | extern void kunmap(struct page *page); | |
| a24401bc | 69 | extern void *kmap_atomic(struct page *page); |
| 3e4d3af5 PZ |
70 | extern void __kunmap_atomic(void *kvaddr); |
| 71 | extern void *kmap_atomic_pfn(unsigned long pfn); | |
| 7e5a69e8 | 72 | #endif |
| d73cd428 NP |
73 | |
| 74 | #endif |