| /* 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; | |
| preempt_disable(); | |
| 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(); | |
| preempt_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(); | |
| preempt_enable(); | |
| } | |
| #endif /* __KERNEL__ */ | |
| #endif /* _ASM_HIGHMEM_H */ |