| /* 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) |
| { |
| 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)); |
| __flush_tlb_one(vaddr); |
| |
| return vaddr; |
| } |
| |
| static inline void __kunmap_atomic(unsigned long vaddr) |
| { |
| int type; |
| |
| if (vaddr < FIXADDR_START) { /* FIXME */ |
| pagefault_enable(); |
| return; |
| } |
| |
| type = kmap_atomic_idx_pop(); |
| |
| #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); |
| __flush_tlb_one(vaddr); |
| } |
| #endif |
| pagefault_enable(); |
| } |
| #endif /* __KERNEL__ */ |
| |
| #endif /* _ASM_HIGHMEM_H */ |