1b8b572e1SStephen Rothwell /* 2b8b572e1SStephen Rothwell * highmem.h: virtual kernel memory mappings for high memory 3b8b572e1SStephen Rothwell * 4b8b572e1SStephen Rothwell * PowerPC version, stolen from the i386 version. 5b8b572e1SStephen Rothwell * 6b8b572e1SStephen Rothwell * Used in CONFIG_HIGHMEM systems for memory pages which 7b8b572e1SStephen Rothwell * are not addressable by direct kernel virtual addresses. 8b8b572e1SStephen Rothwell * 9b8b572e1SStephen Rothwell * Copyright (C) 1999 Gerhard Wichert, Siemens AG 10b8b572e1SStephen Rothwell * Gerhard.Wichert@pdb.siemens.de 11b8b572e1SStephen Rothwell * 12b8b572e1SStephen Rothwell * 13b8b572e1SStephen Rothwell * Redesigned the x86 32-bit VM architecture to deal with 14b8b572e1SStephen Rothwell * up to 16 Terrabyte physical memory. With current x86 CPUs 15b8b572e1SStephen Rothwell * we now support up to 64 Gigabytes physical RAM. 16b8b572e1SStephen Rothwell * 17b8b572e1SStephen Rothwell * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com> 18b8b572e1SStephen Rothwell */ 19b8b572e1SStephen Rothwell 20b8b572e1SStephen Rothwell #ifndef _ASM_HIGHMEM_H 21b8b572e1SStephen Rothwell #define _ASM_HIGHMEM_H 22b8b572e1SStephen Rothwell 23b8b572e1SStephen Rothwell #ifdef __KERNEL__ 24b8b572e1SStephen Rothwell 25b8b572e1SStephen Rothwell #include <linux/interrupt.h> 26b8b572e1SStephen Rothwell #include <asm/kmap_types.h> 27b8b572e1SStephen Rothwell #include <asm/tlbflush.h> 28b8b572e1SStephen Rothwell #include <asm/page.h> 29b8b572e1SStephen Rothwell #include <asm/fixmap.h> 30b8b572e1SStephen Rothwell 31b8b572e1SStephen Rothwell extern pte_t *kmap_pte; 32b8b572e1SStephen Rothwell extern pgprot_t kmap_prot; 33b8b572e1SStephen Rothwell extern pte_t *pkmap_page_table; 34b8b572e1SStephen Rothwell 35b8b572e1SStephen Rothwell /* 36b8b572e1SStephen Rothwell * Right now we initialize only a single pte table. It can be extended 37b8b572e1SStephen Rothwell * easily, subsequent pte tables have to be allocated in one physical 38b8b572e1SStephen Rothwell * chunk of RAM. 39b8b572e1SStephen Rothwell */ 40ca9153a3SIlya Yanok /* 41e1240122SYuri Tikhonov * We use one full pte table with 4K pages. And with 16K/64K/256K pages pte 42e1240122SYuri Tikhonov * table covers enough memory (32MB/512MB/2GB resp.), so that both FIXMAP 43e1240122SYuri Tikhonov * and PKMAP can be placed in a single pte table. We use 512 pages for PKMAP 44e1240122SYuri Tikhonov * in case of 16K/64K/256K page sizes. 45ca9153a3SIlya Yanok */ 46ca9153a3SIlya Yanok #ifdef CONFIG_PPC_4K_PAGES 47ca9153a3SIlya Yanok #define PKMAP_ORDER PTE_SHIFT 48ca9153a3SIlya Yanok #else 49e1240122SYuri Tikhonov #define PKMAP_ORDER 9 50ca9153a3SIlya Yanok #endif 51ca9153a3SIlya Yanok #define LAST_PKMAP (1 << PKMAP_ORDER) 52ca9153a3SIlya Yanok #ifndef CONFIG_PPC_4K_PAGES 53ca9153a3SIlya Yanok #define PKMAP_BASE (FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) 54ca9153a3SIlya Yanok #else 55b8b572e1SStephen Rothwell #define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK) 56ca9153a3SIlya Yanok #endif 57ca9153a3SIlya Yanok #define LAST_PKMAP_MASK (LAST_PKMAP-1) 58b8b572e1SStephen Rothwell #define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) 59b8b572e1SStephen Rothwell #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) 60b8b572e1SStephen Rothwell 61b8b572e1SStephen Rothwell extern void *kmap_high(struct page *page); 62b8b572e1SStephen Rothwell extern void kunmap_high(struct page *page); 63850f6ac3SBenjamin Herrenschmidt extern void *kmap_atomic_prot(struct page *page, enum km_type type, 64850f6ac3SBenjamin Herrenschmidt pgprot_t prot); 65850f6ac3SBenjamin Herrenschmidt extern void kunmap_atomic(void *kvaddr, enum km_type type); 66b8b572e1SStephen Rothwell 67b8b572e1SStephen Rothwell static inline void *kmap(struct page *page) 68b8b572e1SStephen Rothwell { 69b8b572e1SStephen Rothwell might_sleep(); 70b8b572e1SStephen Rothwell if (!PageHighMem(page)) 71b8b572e1SStephen Rothwell return page_address(page); 72b8b572e1SStephen Rothwell return kmap_high(page); 73b8b572e1SStephen Rothwell } 74b8b572e1SStephen Rothwell 75b8b572e1SStephen Rothwell static inline void kunmap(struct page *page) 76b8b572e1SStephen Rothwell { 77b8b572e1SStephen Rothwell BUG_ON(in_interrupt()); 78b8b572e1SStephen Rothwell if (!PageHighMem(page)) 79b8b572e1SStephen Rothwell return; 80b8b572e1SStephen Rothwell kunmap_high(page); 81b8b572e1SStephen Rothwell } 82b8b572e1SStephen Rothwell 83b8b572e1SStephen Rothwell static inline void *kmap_atomic(struct page *page, enum km_type type) 84b8b572e1SStephen Rothwell { 85b8b572e1SStephen Rothwell return kmap_atomic_prot(page, type, kmap_prot); 86b8b572e1SStephen Rothwell } 87b8b572e1SStephen Rothwell 88b8b572e1SStephen Rothwell static inline struct page *kmap_atomic_to_page(void *ptr) 89b8b572e1SStephen Rothwell { 90b8b572e1SStephen Rothwell unsigned long idx, vaddr = (unsigned long) ptr; 91b8b572e1SStephen Rothwell pte_t *pte; 92b8b572e1SStephen Rothwell 93b8b572e1SStephen Rothwell if (vaddr < FIXADDR_START) 94b8b572e1SStephen Rothwell return virt_to_page(ptr); 95b8b572e1SStephen Rothwell 96b8b572e1SStephen Rothwell idx = virt_to_fix(vaddr); 97b8b572e1SStephen Rothwell pte = kmap_pte - (idx - FIX_KMAP_BEGIN); 98b8b572e1SStephen Rothwell return pte_page(*pte); 99b8b572e1SStephen Rothwell } 100b8b572e1SStephen Rothwell 101850f6ac3SBenjamin Herrenschmidt 102b8b572e1SStephen Rothwell #define flush_cache_kmaps() flush_cache_all() 103b8b572e1SStephen Rothwell 104b8b572e1SStephen Rothwell #endif /* __KERNEL__ */ 105b8b572e1SStephen Rothwell 106b8b572e1SStephen Rothwell #endif /* _ASM_HIGHMEM_H */ 107