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https://github.com/Fishwaldo/linux-bl808.git
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4102b53392
This is the meat of the series which prevents any dcache alias creation by always keeping the U and K mapping of a page congruent. If a mapping already exists, and other tries to access the page, prev one is flushed to physical page (wback+inv) Essentially flush_dcache_page()/copy_user_highpage() create K-mapping of a page, but try to defer flushing, unless U-mapping exist. When page is actually mapped to userspace, update_mmu_cache() flushes the K-mapping (in certain cases this can be optimised out) Additonally flush_cache_mm(), flush_cache_range(), flush_cache_page() handle the puring of stale userspace mappings on exit/munmap... flush_anon_page() handles the existing U-mapping for anon page before kernel reads it via the GUP path. Note that while not complete, this is enough to boot a simple dynamically linked Busybox based rootfs Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
73 lines
1.9 KiB
C
73 lines
1.9 KiB
C
/*
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* Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef _ASM_ARC_TLB_H
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#define _ASM_ARC_TLB_H
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#ifdef __KERNEL__
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#include <asm/pgtable.h>
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/* Masks for actual TLB "PD"s */
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#define PTE_BITS_IN_PD0 (_PAGE_GLOBAL | _PAGE_PRESENT)
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#define PTE_BITS_IN_PD1 (PAGE_MASK | _PAGE_CACHEABLE | \
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_PAGE_EXECUTE | _PAGE_WRITE | _PAGE_READ | \
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_PAGE_K_EXECUTE | _PAGE_K_WRITE | _PAGE_K_READ)
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#ifndef __ASSEMBLY__
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#define tlb_flush(tlb) \
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do { \
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if (tlb->fullmm) \
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flush_tlb_mm((tlb)->mm); \
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} while (0)
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/*
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* This pair is called at time of munmap/exit to flush cache and TLB entries
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* for mappings being torn down.
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* 1) cache-flush part -implemented via tlb_start_vma( ) for VIPT aliasing D$
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* 2) tlb-flush part - implemted via tlb_end_vma( ) flushes the TLB range
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*
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* Note, read http://lkml.org/lkml/2004/1/15/6
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*/
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#ifndef CONFIG_ARC_CACHE_VIPT_ALIASING
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#define tlb_start_vma(tlb, vma)
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#else
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#define tlb_start_vma(tlb, vma) \
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do { \
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if (!tlb->fullmm) \
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flush_cache_range(vma, vma->vm_start, vma->vm_end); \
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} while(0)
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#endif
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#define tlb_end_vma(tlb, vma) \
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do { \
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if (!tlb->fullmm) \
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flush_tlb_range(vma, vma->vm_start, vma->vm_end); \
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} while (0)
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#define __tlb_remove_tlb_entry(tlb, ptep, address)
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#include <linux/pagemap.h>
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#include <asm-generic/tlb.h>
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#ifdef CONFIG_ARC_DBG_TLB_PARANOIA
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void tlb_paranoid_check(unsigned int pid_sw, unsigned long address);
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#else
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#define tlb_paranoid_check(a, b)
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#endif
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void arc_mmu_init(void);
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extern char *arc_mmu_mumbojumbo(int cpu_id, char *buf, int len);
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void __init read_decode_mmu_bcr(void);
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#endif /* __ASSEMBLY__ */
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#endif /* __KERNEL__ */
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#endif /* _ASM_ARC_TLB_H */
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