1b2441318SGreg Kroah-Hartman /* SPDX-License-Identifier: GPL-2.0 */ 2b8b572e1SStephen Rothwell /* 3b8b572e1SStephen Rothwell * highmem.h: virtual kernel memory mappings for high memory 4b8b572e1SStephen Rothwell * 5b8b572e1SStephen Rothwell * PowerPC version, stolen from the i386 version. 6b8b572e1SStephen Rothwell * 7b8b572e1SStephen Rothwell * Used in CONFIG_HIGHMEM systems for memory pages which 8b8b572e1SStephen Rothwell * are not addressable by direct kernel virtual addresses. 9b8b572e1SStephen Rothwell * 10b8b572e1SStephen Rothwell * Copyright (C) 1999 Gerhard Wichert, Siemens AG 11b8b572e1SStephen Rothwell * Gerhard.Wichert@pdb.siemens.de 12b8b572e1SStephen Rothwell * 13b8b572e1SStephen Rothwell * 14b8b572e1SStephen Rothwell * Redesigned the x86 32-bit VM architecture to deal with 15b8b572e1SStephen Rothwell * up to 16 Terrabyte physical memory. With current x86 CPUs 16b8b572e1SStephen Rothwell * we now support up to 64 Gigabytes physical RAM. 17b8b572e1SStephen Rothwell * 18b8b572e1SStephen Rothwell * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com> 19b8b572e1SStephen Rothwell */ 20b8b572e1SStephen Rothwell 21b8b572e1SStephen Rothwell #ifndef _ASM_HIGHMEM_H 22b8b572e1SStephen Rothwell #define _ASM_HIGHMEM_H 23b8b572e1SStephen Rothwell 24b8b572e1SStephen Rothwell #ifdef __KERNEL__ 25b8b572e1SStephen Rothwell 26b8b572e1SStephen Rothwell #include <linux/interrupt.h> 27b8b572e1SStephen Rothwell #include <asm/kmap_types.h> 28b8b572e1SStephen Rothwell #include <asm/tlbflush.h> 29b8b572e1SStephen Rothwell #include <asm/page.h> 30b8b572e1SStephen Rothwell #include <asm/fixmap.h> 31b8b572e1SStephen Rothwell 32b8b572e1SStephen Rothwell extern pte_t *kmap_pte; 33b8b572e1SStephen Rothwell extern pgprot_t kmap_prot; 34b8b572e1SStephen Rothwell extern pte_t *pkmap_page_table; 35b8b572e1SStephen Rothwell 36b8b572e1SStephen Rothwell /* 37b8b572e1SStephen Rothwell * Right now we initialize only a single pte table. It can be extended 38b8b572e1SStephen Rothwell * easily, subsequent pte tables have to be allocated in one physical 39b8b572e1SStephen Rothwell * chunk of RAM. 40b8b572e1SStephen Rothwell */ 41ca9153a3SIlya Yanok /* 42e1240122SYuri Tikhonov * We use one full pte table with 4K pages. And with 16K/64K/256K pages pte 43e1240122SYuri Tikhonov * table covers enough memory (32MB/512MB/2GB resp.), so that both FIXMAP 44e1240122SYuri Tikhonov * and PKMAP can be placed in a single pte table. We use 512 pages for PKMAP 45e1240122SYuri Tikhonov * in case of 16K/64K/256K page sizes. 46ca9153a3SIlya Yanok */ 47ca9153a3SIlya Yanok #ifdef CONFIG_PPC_4K_PAGES 48ca9153a3SIlya Yanok #define PKMAP_ORDER PTE_SHIFT 49ca9153a3SIlya Yanok #else 50e1240122SYuri Tikhonov #define PKMAP_ORDER 9 51ca9153a3SIlya Yanok #endif 52ca9153a3SIlya Yanok #define LAST_PKMAP (1 << PKMAP_ORDER) 53ca9153a3SIlya Yanok #ifndef CONFIG_PPC_4K_PAGES 54ca9153a3SIlya Yanok #define PKMAP_BASE (FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) 55ca9153a3SIlya Yanok #else 56b8b572e1SStephen Rothwell #define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK) 57ca9153a3SIlya Yanok #endif 58ca9153a3SIlya Yanok #define LAST_PKMAP_MASK (LAST_PKMAP-1) 59b8b572e1SStephen Rothwell #define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) 60b8b572e1SStephen Rothwell #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) 61b8b572e1SStephen Rothwell 62b8b572e1SStephen Rothwell extern void *kmap_high(struct page *page); 63b8b572e1SStephen Rothwell extern void kunmap_high(struct page *page); 643e4d3af5SPeter Zijlstra extern void *kmap_atomic_prot(struct page *page, pgprot_t prot); 653e4d3af5SPeter Zijlstra extern void __kunmap_atomic(void *kvaddr); 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 83a24401bcSCong Wang static inline void *kmap_atomic(struct page *page) 84b8b572e1SStephen Rothwell { 853e4d3af5SPeter Zijlstra return kmap_atomic_prot(page, kmap_prot); 86b8b572e1SStephen Rothwell } 87b8b572e1SStephen Rothwell 88850f6ac3SBenjamin Herrenschmidt 89b8b572e1SStephen Rothwell #define flush_cache_kmaps() flush_cache_all() 90b8b572e1SStephen Rothwell 91b8b572e1SStephen Rothwell #endif /* __KERNEL__ */ 92b8b572e1SStephen Rothwell 93b8b572e1SStephen Rothwell #endif /* _ASM_HIGHMEM_H */ 94