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| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
|---|---|
| 2 | #ifndef _ASM_HIGHMEM_H |
| 3 | #define _ASM_HIGHMEM_H |
| 4 | |
| 5 | #include <asm/cachetype.h> |
| 6 | #include <asm/fixmap.h> |
| 7 | |
| 8 | #define PKMAP_BASE (PAGE_OFFSET - PMD_SIZE) |
| 9 | #define LAST_PKMAP PTRS_PER_PTE |
| 10 | #define LAST_PKMAP_MASK (LAST_PKMAP - 1) |
| 11 | #define PKMAP_NR(virt) (((virt) - PKMAP_BASE) >> PAGE_SHIFT) |
| 12 | #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) |
| 13 | |
| 14 | #define flush_cache_kmaps() \ |
| 15 | do { \ |
| 16 | if (cache_is_vivt()) \ |
| 17 | flush_cache_all(); \ |
| 18 | } while (0) |
| 19 | |
| 20 | extern pte_t *pkmap_page_table; |
| 21 | |
| 22 | /* |
| 23 | * The reason for kmap_high_get() is to ensure that the currently kmap'd |
| 24 | * page usage count does not decrease to zero while we're using its |
| 25 | * existing virtual mapping in an atomic context. With a VIVT cache this |
| 26 | * is essential to do, but with a VIPT cache this is only an optimization |
| 27 | * so not to pay the price of establishing a second mapping if an existing |
| 28 | * one can be used. However, on platforms without hardware TLB maintenance |
| 29 | * broadcast, we simply cannot use ARCH_NEEDS_KMAP_HIGH_GET at all since |
| 30 | * the locking involved must also disable IRQs which is incompatible with |
| 31 | * the IPI mechanism used by global TLB operations. |
| 32 | */ |
| 33 | #define ARCH_NEEDS_KMAP_HIGH_GET |
| 34 | #if defined(CONFIG_SMP) && defined(CONFIG_CPU_TLB_V6) |
| 35 | #undef ARCH_NEEDS_KMAP_HIGH_GET |
| 36 | #if defined(CONFIG_HIGHMEM) && defined(CONFIG_CPU_CACHE_VIVT) |
| 37 | #error "The sum of features in your kernel config cannot be supported together" |
| 38 | #endif |
| 39 | #endif |
| 40 | |
| 41 | /* |
| 42 | * Needed to be able to broadcast the TLB invalidation for kmap. |
| 43 | */ |
| 44 | #ifdef CONFIG_ARM_ERRATA_798181 |
| 45 | #undef ARCH_NEEDS_KMAP_HIGH_GET |
| 46 | #endif |
| 47 | |
| 48 | #ifdef ARCH_NEEDS_KMAP_HIGH_GET |
| 49 | extern void *kmap_high_get(const struct page *page); |
| 50 | |
| 51 | static inline void *arch_kmap_local_high_get(const struct page *page) |
| 52 | { |
| 53 | if (IS_ENABLED(CONFIG_DEBUG_HIGHMEM) && !cache_is_vivt()) |
| 54 | return NULL; |
| 55 | return kmap_high_get(page); |
| 56 | } |
| 57 | #define arch_kmap_local_high_get arch_kmap_local_high_get |
| 58 | |
| 59 | #else /* ARCH_NEEDS_KMAP_HIGH_GET */ |
| 60 | static inline void *kmap_high_get(const struct page *page) |
| 61 | { |
| 62 | return NULL; |
| 63 | } |
| 64 | #endif /* !ARCH_NEEDS_KMAP_HIGH_GET */ |
| 65 | |
| 66 | #define arch_kmap_local_post_map(vaddr, pteval) \ |
| 67 | local_flush_tlb_kernel_page(vaddr) |
| 68 | |
| 69 | #define arch_kmap_local_pre_unmap(vaddr) \ |
| 70 | do { \ |
| 71 | if (cache_is_vivt()) \ |
| 72 | __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); \ |
| 73 | } while (0) |
| 74 | |
| 75 | #define arch_kmap_local_post_unmap(vaddr) \ |
| 76 | local_flush_tlb_kernel_page(vaddr) |
| 77 | |
| 78 | #endif |
| 79 |
Warning: This file is not a C or C++ file. It does not have highlighting.