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Diffstat (limited to 'arch/sparc/include/asm/highmem.h')
-rw-r--r-- | arch/sparc/include/asm/highmem.h | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/arch/sparc/include/asm/highmem.h b/arch/sparc/include/asm/highmem.h new file mode 100644 index 000000000..18d776925 --- /dev/null +++ b/arch/sparc/include/asm/highmem.h @@ -0,0 +1,79 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * highmem.h: virtual kernel memory mappings for high memory + * + * Used in CONFIG_HIGHMEM systems for memory pages which + * are not addressable by direct kernel virtual addresses. + * + * Copyright (C) 1999 Gerhard Wichert, Siemens AG + * Gerhard.Wichert@pdb.siemens.de + * + * + * Redesigned the x86 32-bit VM architecture to deal with + * up to 16 Terrabyte physical memory. With current x86 CPUs + * we now support up to 64 Gigabytes physical RAM. + * + * Copyright (C) 1999 Ingo Molnar <mingo@redhat.com> + */ + +#ifndef _ASM_HIGHMEM_H +#define _ASM_HIGHMEM_H + +#ifdef __KERNEL__ + +#include <linux/interrupt.h> +#include <asm/vaddrs.h> +#include <asm/kmap_types.h> +#include <asm/pgtable.h> + +/* declarations for highmem.c */ +extern unsigned long highstart_pfn, highend_pfn; + +extern pgprot_t kmap_prot; +extern pte_t *pkmap_page_table; + +void kmap_init(void) __init; + +/* + * 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. Currently the simplest way to do this is to align the + * pkmap region on a pagetable boundary (4MB). + */ +#define LAST_PKMAP 1024 +#define PKMAP_SIZE (LAST_PKMAP << PAGE_SHIFT) +#define PKMAP_BASE PMD_ALIGN(SRMMU_NOCACHE_VADDR + (SRMMU_MAX_NOCACHE_PAGES << PAGE_SHIFT)) + +#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)) + +#define PKMAP_END (PKMAP_ADDR(LAST_PKMAP)) + +void *kmap_high(struct page *page); +void kunmap_high(struct page *page); + +static inline void *kmap(struct page *page) +{ + BUG_ON(in_interrupt()); + if (!PageHighMem(page)) + return page_address(page); + return kmap_high(page); +} + +static inline void kunmap(struct page *page) +{ + BUG_ON(in_interrupt()); + if (!PageHighMem(page)) + return; + kunmap_high(page); +} + +void *kmap_atomic(struct page *page); +void __kunmap_atomic(void *kvaddr); + +#define flush_cache_kmaps() flush_cache_all() + +#endif /* __KERNEL__ */ + +#endif /* _ASM_HIGHMEM_H */ |