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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-06 01:02:30 +0000 |
commit | 76cb841cb886eef6b3bee341a2266c76578724ad (patch) | |
tree | f5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/mips/include/asm/highmem.h | |
parent | Initial commit. (diff) | |
download | linux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip |
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/mips/include/asm/highmem.h')
-rw-r--r-- | arch/mips/include/asm/highmem.h | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/arch/mips/include/asm/highmem.h b/arch/mips/include/asm/highmem.h new file mode 100644 index 000000000..9d84aafc3 --- /dev/null +++ b/arch/mips/include/asm/highmem.h @@ -0,0 +1,66 @@ +/* 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 Terabyte 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/bug.h> +#include <linux/interrupt.h> +#include <linux/uaccess.h> +#include <asm/cpu-features.h> +#include <asm/kmap_types.h> + +/* declarations for highmem.c */ +extern unsigned long highstart_pfn, highend_pfn; + +extern pte_t *pkmap_page_table; + +/* + * 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. + */ +#ifdef CONFIG_PHYS_ADDR_T_64BIT +#define LAST_PKMAP 512 +#else +#define LAST_PKMAP 1024 +#endif + +#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 void * kmap_high(struct page *page); +extern void kunmap_high(struct page *page); + +extern void *kmap(struct page *page); +extern void kunmap(struct page *page); +extern void *kmap_atomic(struct page *page); +extern void __kunmap_atomic(void *kvaddr); +extern void *kmap_atomic_pfn(unsigned long pfn); + +#define flush_cache_kmaps() BUG_ON(cpu_has_dc_aliases) + +extern void kmap_init(void); + +#define kmap_prot PAGE_KERNEL + +#endif /* __KERNEL__ */ + +#endif /* _ASM_HIGHMEM_H */ |