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Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
66 lines
1.8 KiB
C
66 lines
1.8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* This file contains the routines for handling the MMU.
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*
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* Copyright (C) 2007 Xilinx, Inc. All rights reserved.
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*
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* Derived from arch/ppc/mm/4xx_mmu.c:
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* -- paulus
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*
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* Derived from arch/ppc/mm/init.c:
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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*
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* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
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* and Cort Dougan (PReP) (cort@cs.nmt.edu)
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* Copyright (C) 1996 Paul Mackerras
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* Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
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*
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* Derived from "arch/i386/mm/init.c"
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
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*/
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#include <linux/mm.h>
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#include <linux/init.h>
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#include <asm/tlbflush.h>
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#include <asm/mmu_context.h>
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mm_context_t next_mmu_context;
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unsigned long context_map[LAST_CONTEXT / BITS_PER_LONG + 1];
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atomic_t nr_free_contexts;
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struct mm_struct *context_mm[LAST_CONTEXT+1];
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/*
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* Initialize the context management stuff.
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*/
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void __init mmu_context_init(void)
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{
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/*
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* The use of context zero is reserved for the kernel.
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* This code assumes FIRST_CONTEXT < 32.
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*/
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context_map[0] = (1 << FIRST_CONTEXT) - 1;
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next_mmu_context = FIRST_CONTEXT;
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atomic_set(&nr_free_contexts, LAST_CONTEXT - FIRST_CONTEXT + 1);
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}
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/*
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* Steal a context from a task that has one at the moment.
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*
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* This isn't an LRU system, it just frees up each context in
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* turn (sort-of pseudo-random replacement :). This would be the
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* place to implement an LRU scheme if anyone were motivated to do it.
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*/
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void steal_context(void)
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{
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struct mm_struct *mm;
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/* free up context `next_mmu_context' */
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/* if we shouldn't free context 0, don't... */
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if (next_mmu_context < FIRST_CONTEXT)
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next_mmu_context = FIRST_CONTEXT;
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mm = context_mm[next_mmu_context];
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flush_tlb_mm(mm);
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destroy_context(mm);
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}
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