fs: use kmem_cache_zalloc instead
[pv_ops_mirror.git] / include / asm-sparc / highmem.h
blob3de42e776274e1436a18417202326eab98130277
1 /*
2 * highmem.h: virtual kernel memory mappings for high memory
4 * Used in CONFIG_HIGHMEM systems for memory pages which
5 * are not addressable by direct kernel virtual addresses.
7 * Copyright (C) 1999 Gerhard Wichert, Siemens AG
8 * Gerhard.Wichert@pdb.siemens.de
11 * Redesigned the x86 32-bit VM architecture to deal with
12 * up to 16 Terrabyte physical memory. With current x86 CPUs
13 * we now support up to 64 Gigabytes physical RAM.
15 * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
18 #ifndef _ASM_HIGHMEM_H
19 #define _ASM_HIGHMEM_H
21 #ifdef __KERNEL__
23 #include <linux/interrupt.h>
24 #include <asm/fixmap.h>
25 #include <asm/vaddrs.h>
26 #include <asm/kmap_types.h>
27 #include <asm/pgtable.h>
29 /* declarations for highmem.c */
30 extern unsigned long highstart_pfn, highend_pfn;
32 extern pte_t *kmap_pte;
33 extern pgprot_t kmap_prot;
34 extern pte_t *pkmap_page_table;
36 extern void kmap_init(void) __init;
39 * Right now we initialize only a single pte table. It can be extended
40 * easily, subsequent pte tables have to be allocated in one physical
41 * chunk of RAM. Currently the simplest way to do this is to align the
42 * pkmap region on a pagetable boundary (4MB).
44 #define LAST_PKMAP 1024
45 #define PKMAP_SIZE (LAST_PKMAP << PAGE_SHIFT)
46 #define PKMAP_BASE PMD_ALIGN(SRMMU_NOCACHE_VADDR + (SRMMU_MAX_NOCACHE_PAGES << PAGE_SHIFT))
48 #define LAST_PKMAP_MASK (LAST_PKMAP - 1)
49 #define PKMAP_NR(virt) ((virt - PKMAP_BASE) >> PAGE_SHIFT)
50 #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
52 #define PKMAP_END (PKMAP_ADDR(LAST_PKMAP))
54 extern void *kmap_high(struct page *page);
55 extern void kunmap_high(struct page *page);
57 static inline void *kmap(struct page *page)
59 BUG_ON(in_interrupt());
60 if (!PageHighMem(page))
61 return page_address(page);
62 return kmap_high(page);
65 static inline void kunmap(struct page *page)
67 BUG_ON(in_interrupt());
68 if (!PageHighMem(page))
69 return;
70 kunmap_high(page);
73 extern void *kmap_atomic(struct page *page, enum km_type type);
74 extern void kunmap_atomic(void *kvaddr, enum km_type type);
75 extern struct page *kmap_atomic_to_page(void *vaddr);
77 #define flush_cache_kmaps() flush_cache_all()
79 #endif /* __KERNEL__ */
81 #endif /* _ASM_HIGHMEM_H */