1d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre#ifndef _ASM_HIGHMEM_H 2d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre#define _ASM_HIGHMEM_H 3d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre 4d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre#include <asm/kmap_types.h> 5d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre 6d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre#define PKMAP_BASE (PAGE_OFFSET - PMD_SIZE) 7d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre#define LAST_PKMAP PTRS_PER_PTE 8d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre#define LAST_PKMAP_MASK (LAST_PKMAP - 1) 9d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre#define PKMAP_NR(virt) (((virt) - PKMAP_BASE) >> PAGE_SHIFT) 10d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) 11d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre 12d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre#define kmap_prot PAGE_KERNEL 13d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre 147e5a69e83ba7a0d5917ad830f417cba8b8d6aa72Nicolas Pitre#define flush_cache_kmaps() \ 157e5a69e83ba7a0d5917ad830f417cba8b8d6aa72Nicolas Pitre do { \ 167e5a69e83ba7a0d5917ad830f417cba8b8d6aa72Nicolas Pitre if (cache_is_vivt()) \ 177e5a69e83ba7a0d5917ad830f417cba8b8d6aa72Nicolas Pitre flush_cache_all(); \ 187e5a69e83ba7a0d5917ad830f417cba8b8d6aa72Nicolas Pitre } while (0) 19d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre 20d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitreextern pte_t *pkmap_page_table; 21a05e54c103b0b8e1dab5d04b411f1d48387c4903Liu Huaextern pte_t *fixmap_page_table; 22d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre 23aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitreextern void *kmap_high(struct page *page); 24aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitreextern void kunmap_high(struct page *page); 25aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre 26aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre/* 27aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre * The reason for kmap_high_get() is to ensure that the currently kmap'd 28aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre * page usage count does not decrease to zero while we're using its 29aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre * existing virtual mapping in an atomic context. With a VIVT cache this 30aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre * is essential to do, but with a VIPT cache this is only an optimization 31aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre * so not to pay the price of establishing a second mapping if an existing 32aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre * one can be used. However, on platforms without hardware TLB maintenance 33aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre * broadcast, we simply cannot use ARCH_NEEDS_KMAP_HIGH_GET at all since 34aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre * the locking involved must also disable IRQs which is incompatible with 35aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre * the IPI mechanism used by global TLB operations. 36aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre */ 3743377453af83b8ff8c1c731da1508bd6b84ebfeaNicolas Pitre#define ARCH_NEEDS_KMAP_HIGH_GET 38aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre#if defined(CONFIG_SMP) && defined(CONFIG_CPU_TLB_V6) 39aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre#undef ARCH_NEEDS_KMAP_HIGH_GET 40aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre#if defined(CONFIG_HIGHMEM) && defined(CONFIG_CPU_CACHE_VIVT) 41aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre#error "The sum of features in your kernel config cannot be supported together" 42aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre#endif 43aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre#endif 4443377453af83b8ff8c1c731da1508bd6b84ebfeaNicolas Pitre 4593dc68876b608da041fe40ed39424b0fcd5aa2fbCatalin Marinas/* 4693dc68876b608da041fe40ed39424b0fcd5aa2fbCatalin Marinas * Needed to be able to broadcast the TLB invalidation for kmap. 4793dc68876b608da041fe40ed39424b0fcd5aa2fbCatalin Marinas */ 4893dc68876b608da041fe40ed39424b0fcd5aa2fbCatalin Marinas#ifdef CONFIG_ARM_ERRATA_798181 4993dc68876b608da041fe40ed39424b0fcd5aa2fbCatalin Marinas#undef ARCH_NEEDS_KMAP_HIGH_GET 5093dc68876b608da041fe40ed39424b0fcd5aa2fbCatalin Marinas#endif 5193dc68876b608da041fe40ed39424b0fcd5aa2fbCatalin Marinas 52aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre#ifdef ARCH_NEEDS_KMAP_HIGH_GET 5343377453af83b8ff8c1c731da1508bd6b84ebfeaNicolas Pitreextern void *kmap_high_get(struct page *page); 54aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre#else 55aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitrestatic inline void *kmap_high_get(struct page *page) 56aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre{ 57aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre return NULL; 58aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre} 59aaa50048f6ce44af66ce0389d4cc6a8348333271Nicolas Pitre#endif 60d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre 617e5a69e83ba7a0d5917ad830f417cba8b8d6aa72Nicolas Pitre/* 627e5a69e83ba7a0d5917ad830f417cba8b8d6aa72Nicolas Pitre * The following functions are already defined by <linux/highmem.h> 637e5a69e83ba7a0d5917ad830f417cba8b8d6aa72Nicolas Pitre * when CONFIG_HIGHMEM is not set. 647e5a69e83ba7a0d5917ad830f417cba8b8d6aa72Nicolas Pitre */ 657e5a69e83ba7a0d5917ad830f417cba8b8d6aa72Nicolas Pitre#ifdef CONFIG_HIGHMEM 66d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitreextern void *kmap(struct page *page); 67d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitreextern void kunmap(struct page *page); 68a24401bcf4a67c8fe17e649e74eeb09b08b79ef5Cong Wangextern void *kmap_atomic(struct page *page); 693e4d3af501cccdc8a8cca41bdbe57d54ad7e7e73Peter Zijlstraextern void __kunmap_atomic(void *kvaddr); 703e4d3af501cccdc8a8cca41bdbe57d54ad7e7e73Peter Zijlstraextern void *kmap_atomic_pfn(unsigned long pfn); 71d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitreextern struct page *kmap_atomic_to_page(const void *ptr); 727e5a69e83ba7a0d5917ad830f417cba8b8d6aa72Nicolas Pitre#endif 73d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre 74d73cd42893f4cdc06e6829fea2347bb92cb789d1Nicolas Pitre#endif 75