diff options
author | Ingo Molnar <mingo@elte.hu> | 2009-06-07 12:22:15 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2009-06-07 12:22:15 +0200 |
commit | 5f4457a4f62cc9d78e04c0eb12ff0540899aad89 (patch) | |
tree | 0b973d527ea6b2ae31e08da0746b4965a3c5a6d8 /arch/mn10300/include/asm/highmem.h | |
parent | 9b94b3a19b13e094c10f65f24bc358f6ffe4eacd (diff) | |
parent | b87297fb405ef13cac375f202d114323b076a56d (diff) |
Merge branch 'linus' into x86/cpu
Diffstat (limited to 'arch/mn10300/include/asm/highmem.h')
-rw-r--r-- | arch/mn10300/include/asm/highmem.h | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/arch/mn10300/include/asm/highmem.h b/arch/mn10300/include/asm/highmem.h new file mode 100644 index 00000000000..90f2abb04bf --- /dev/null +++ b/arch/mn10300/include/asm/highmem.h @@ -0,0 +1,116 @@ +/* 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 unsigned long kmap_atomic(struct page *page, enum km_type type) +{ + enum fixed_addresses idx; + unsigned long vaddr; + + if (page < highmem_start_page) + return page_address(page); + + debug_kmap_atomic(type); + 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)); + __flush_tlb_one(vaddr); + + return vaddr; +} + +static inline void kunmap_atomic(unsigned long vaddr, enum km_type type) +{ +#if HIGHMEM_DEBUG + enum fixed_addresses idx = type + KM_TYPE_NR * smp_processor_id(); + + if (vaddr < FIXADDR_START) /* FIXME */ + return; + + 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); + __flush_tlb_one(vaddr); +#endif +} + +#endif /* __KERNEL__ */ + +#endif /* _ASM_HIGHMEM_H */ |