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(struct page *page); 50 arch_kmap_local_high_get(struct page * page)51static inline void *arch_kmap_local_high_get(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 */ kmap_high_get(struct page * page)60static inline void *kmap_high_get(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