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Release 4.14 arch/openrisc/mm/tlb.c

Directory: arch/openrisc/mm
/*
 * OpenRISC tlb.c
 *
 * Linux architectural port borrowing liberally from similar works of
 * others.  All original copyrights apply as per the original source
 * declaration.
 *
 * Modifications for the OpenRISC architecture:
 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
 * Copyright (C) 2010-2011 Julius Baxter <julius.baxter@orsoc.se>
 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
 *
 *      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.
 */

#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/init.h>

#include <asm/segment.h>
#include <asm/tlbflush.h>
#include <asm/pgtable.h>
#include <asm/mmu_context.h>
#include <asm/spr_defs.h>


#define NO_CONTEXT -1


#define NUM_DTLB_SETS (1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> \
                            SPR_DMMUCFGR_NTS_OFF))

#define NUM_ITLB_SETS (1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> \
                            SPR_IMMUCFGR_NTS_OFF))

#define DTLB_OFFSET(addr) (((addr) >> PAGE_SHIFT) & (NUM_DTLB_SETS-1))

#define ITLB_OFFSET(addr) (((addr) >> PAGE_SHIFT) & (NUM_ITLB_SETS-1))
/*
 * Invalidate all TLB entries.
 *
 * This comes down to setting the 'valid' bit for all xTLBMR registers to 0.
 * Easiest way to accomplish this is to just zero out the xTLBMR register
 * completely.
 *
 */


void flush_tlb_all(void) { int i; unsigned long num_tlb_sets; /* Determine number of sets for IMMU. */ /* FIXME: Assumption is I & D nsets equal. */ num_tlb_sets = NUM_ITLB_SETS; for (i = 0; i < num_tlb_sets; i++) { mtspr_off(SPR_DTLBMR_BASE(0), i, 0); mtspr_off(SPR_ITLBMR_BASE(0), i, 0); } }

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Jonas Bonn59100.00%1100.00%
Total59100.00%1100.00%

#define have_dtlbeir (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_TEIRI) #define have_itlbeir (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_TEIRI) /* * Invalidate a single page. This is what the xTLBEIR register is for. * * There's no point in checking the vma for PAGE_EXEC to determine whether it's * the data or instruction TLB that should be flushed... that would take more * than the few instructions that the following compiles down to! * * The case where we don't have the xTLBEIR register really only works for * MMU's with a single way and is hard-coded that way. */ #define flush_dtlb_page_eir(addr) mtspr(SPR_DTLBEIR, addr) #define flush_dtlb_page_no_eir(addr) \ mtspr_off(SPR_DTLBMR_BASE(0), DTLB_OFFSET(addr), 0); #define flush_itlb_page_eir(addr) mtspr(SPR_ITLBEIR, addr) #define flush_itlb_page_no_eir(addr) \ mtspr_off(SPR_ITLBMR_BASE(0), ITLB_OFFSET(addr), 0);
void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr) { if (have_dtlbeir) flush_dtlb_page_eir(addr); else flush_dtlb_page_no_eir(addr); if (have_itlbeir) flush_itlb_page_eir(addr); else flush_itlb_page_no_eir(addr); }

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Jonas Bonn44100.00%1100.00%
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void flush_tlb_range(struct vm_area_struct *vma, unsigned long start, unsigned long end) { int addr; bool dtlbeir; bool itlbeir; dtlbeir = have_dtlbeir; itlbeir = have_itlbeir; for (addr = start; addr < end; addr += PAGE_SIZE) { if (dtlbeir) flush_dtlb_page_eir(addr); else flush_dtlb_page_no_eir(addr); if (itlbeir) flush_itlb_page_eir(addr); else flush_itlb_page_no_eir(addr); } }

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Jonas Bonn81100.00%1100.00%
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/* * Invalidate the selected mm context only. * * FIXME: Due to some bug here, we're flushing everything for now. * This should be changed to loop over over mm and call flush_tlb_range. */
void flush_tlb_mm(struct mm_struct *mm) { /* Was seeing bugs with the mm struct passed to us. Scrapped most of this function. */ /* Several architctures do this */ flush_tlb_all(); }

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Jonas Bonn15100.00%1100.00%
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/* called in schedule() just before actually doing the switch_to */
void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *next_tsk) { /* remember the pgd for the fault handlers * this is similar to the pgd register in some other CPU's. * we need our own copy of it because current and active_mm * might be invalid at points where we still need to derefer * the pgd. */ current_pgd = next->pgd; /* We don't have context support implemented, so flush all * entries belonging to previous map */ if (prev != next) flush_tlb_mm(prev); }

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Jonas Bonn39100.00%1100.00%
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/* * Initialize the context related info for a new mm_struct * instance. */
int init_new_context(struct task_struct *tsk, struct mm_struct *mm) { mm->context = NO_CONTEXT; return 0; }

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Jonas Bonn24100.00%1100.00%
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/* called by __exit_mm to destroy the used MMU context if any before * destroying the mm itself. this is only called when the last user of the mm * drops it. */
void destroy_context(struct mm_struct *mm) { flush_tlb_mm(mm); }

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Jonas Bonn15100.00%1100.00%
Total15100.00%1100.00%

/* called once during VM initialization, from init.c */
void __init tlb_init(void) { /* Do nothing... */ /* invalidate the entire TLB */ /* flush_tlb_all(); */ }

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Jonas Bonn11100.00%1100.00%
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Jonas Bonn402100.00%1100.00%
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Directory: arch/openrisc/mm
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