/* MN10300 Virtual kernel memory mappings for high memory * * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * - Derived from include/asm-i386/highmem.h * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public Licence * as published by the Free Software Foundation; either version * 2 of the Licence, or (at your option) any later version. */ #ifndef _ASM_HIGHMEM_H #define _ASM_HIGHMEM_H #ifdef __KERNEL__ #include <linux/init.h> #include <linux/interrupt.h> #include <linux/highmem.h> #include <asm/kmap_types.h> #include <asm/pgtable.h> /* undef for production */ #undef HIGHMEM_DEBUG /* declarations for highmem.c */ extern unsigned long highstart_pfn, highend_pfn; extern pte_t *kmap_pte; extern pgprot_t kmap_prot; extern pte_t *pkmap_page_table; extern void __init kmap_init(void); /* * Right now we initialize only a single pte table. It can be extended * easily, subsequent pte tables have to be allocated in one physical * chunk of RAM. */ #define PKMAP_BASE 0xfe000000UL #define LAST_PKMAP 1024 #define LAST_PKMAP_MASK (LAST_PKMAP - 1) #define PKMAP_NR(virt) ((virt - PKMAP_BASE) >> PAGE_SHIFT) #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) extern unsigned long kmap_high(struct page *page); extern void kunmap_high(struct page *page); static inline unsigned long kmap(struct page *page) { if (in_interrupt()) BUG(); if (page < highmem_start_page) return page_address(page); return kmap_high(page); } static inline void kunmap(struct page *page) { if (in_interrupt()) BUG(); if (page < highmem_start_page) return; kunmap_high(page); } /* * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap * gives a more generic (and caching) interface. But kmap_atomic can * be used in IRQ contexts, so in some (very limited) cases we need * it. */ static inline void *kmap_atomic(struct page *page) { unsigned long vaddr; int idx, type; pagefault_disable(); if (page < highmem_start_page) return page_address(page); type = kmap_atomic_idx_push(); idx = type + KM_TYPE_NR * smp_processor_id(); vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); #if HIGHMEM_DEBUG if (!pte_none(*(kmap_pte - idx))) BUG(); #endif set_pte(kmap_pte - idx, mk_pte(page, kmap_prot)); local_flush_tlb_one(vaddr); return (void *)vaddr; } static inline void __kunmap_atomic(unsigned long vaddr) { int type; if (vaddr < FIXADDR_START) { /* FIXME */ pagefault_enable(); return; } type = kmap_atomic_idx(); #if HIGHMEM_DEBUG { unsigned int idx; idx = type + KM_TYPE_NR * smp_processor_id(); if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)) BUG(); /* * force other mappings to Oops if they'll try to access * this pte without first remap it */ pte_clear(kmap_pte - idx); local_flush_tlb_one(vaddr); } #endif kmap_atomic_idx_pop(); pagefault_enable(); } #endif /* __KERNEL__ */ #endif /* _ASM_HIGHMEM_H */