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725a269b3d
All PTEs used by PKMAP should be allocated in a contiguous memory area, but we do not currently have a mechanism to enforce that, so ensure that we don't try to allocate more entries than would fit in a single page. Current fixed value of 1024 would not work with XPA enabled when sizeof(pte_t)==8 and we need two pages to store pte tables. Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/15949/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
65 lines
1.7 KiB
C
65 lines
1.7 KiB
C
/*
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* highmem.h: virtual kernel memory mappings for high memory
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*
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* Used in CONFIG_HIGHMEM systems for memory pages which
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* are not addressable by direct kernel virtual addresses.
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*
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* Copyright (C) 1999 Gerhard Wichert, Siemens AG
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* Gerhard.Wichert@pdb.siemens.de
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*
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*
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* Redesigned the x86 32-bit VM architecture to deal with
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* up to 16 Terabyte physical memory. With current x86 CPUs
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* we now support up to 64 Gigabytes physical RAM.
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*
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* Copyright (C) 1999 Ingo Molnar <mingo@redhat.com>
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*/
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#ifndef _ASM_HIGHMEM_H
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#define _ASM_HIGHMEM_H
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#ifdef __KERNEL__
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#include <linux/bug.h>
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#include <linux/interrupt.h>
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#include <linux/uaccess.h>
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#include <asm/cpu-features.h>
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#include <asm/kmap_types.h>
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/* declarations for highmem.c */
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extern unsigned long highstart_pfn, highend_pfn;
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extern pte_t *pkmap_page_table;
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/*
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* Right now we initialize only a single pte table. It can be extended
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* easily, subsequent pte tables have to be allocated in one physical
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* chunk of RAM.
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*/
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#ifdef CONFIG_PHYS_ADDR_T_64BIT
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#define LAST_PKMAP 512
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#else
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#define LAST_PKMAP 1024
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#endif
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#define LAST_PKMAP_MASK (LAST_PKMAP-1)
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#define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT)
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#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT))
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extern void * kmap_high(struct page *page);
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extern void kunmap_high(struct page *page);
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extern void *kmap(struct page *page);
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extern void kunmap(struct page *page);
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extern void *kmap_atomic(struct page *page);
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extern void __kunmap_atomic(void *kvaddr);
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extern void *kmap_atomic_pfn(unsigned long pfn);
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#define flush_cache_kmaps() BUG_ON(cpu_has_dc_aliases)
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extern void kmap_init(void);
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#define kmap_prot PAGE_KERNEL
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#endif /* __KERNEL__ */
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#endif /* _ASM_HIGHMEM_H */
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