4 * Linux architectural port borrowing liberally from similar works of
5 * others. All original copyrights apply as per the original source
8 * Modifications for the OpenRISC architecture:
9 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
10 * Copyright (C) 2010-2011 Julius Baxter <julius.baxter@orsoc.se>
11 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License
15 * as published by the Free Software Foundation; either version
16 * 2 of the License, or (at your option) any later version.
19 #include <linux/sched.h>
20 #include <linux/kernel.h>
21 #include <linux/errno.h>
22 #include <linux/string.h>
23 #include <linux/types.h>
24 #include <linux/ptrace.h>
25 #include <linux/mman.h>
27 #include <linux/init.h>
29 #include <asm/tlbflush.h>
30 #include <asm/pgtable.h>
31 #include <asm/mmu_context.h>
32 #include <asm/spr_defs.h>
36 #define NUM_DTLB_SETS (1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> \
37 SPR_DMMUCFGR_NTS_OFF))
38 #define NUM_ITLB_SETS (1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> \
39 SPR_IMMUCFGR_NTS_OFF))
40 #define DTLB_OFFSET(addr) (((addr) >> PAGE_SHIFT) & (NUM_DTLB_SETS-1))
41 #define ITLB_OFFSET(addr) (((addr) >> PAGE_SHIFT) & (NUM_ITLB_SETS-1))
43 * Invalidate all TLB entries.
45 * This comes down to setting the 'valid' bit for all xTLBMR registers to 0.
46 * Easiest way to accomplish this is to just zero out the xTLBMR register
51 void local_flush_tlb_all(void)
54 unsigned long num_tlb_sets;
56 /* Determine number of sets for IMMU. */
57 /* FIXME: Assumption is I & D nsets equal. */
58 num_tlb_sets = NUM_ITLB_SETS;
60 for (i = 0; i < num_tlb_sets; i++) {
61 mtspr_off(SPR_DTLBMR_BASE(0), i, 0);
62 mtspr_off(SPR_ITLBMR_BASE(0), i, 0);
66 #define have_dtlbeir (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_TEIRI)
67 #define have_itlbeir (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_TEIRI)
70 * Invalidate a single page. This is what the xTLBEIR register is for.
72 * There's no point in checking the vma for PAGE_EXEC to determine whether it's
73 * the data or instruction TLB that should be flushed... that would take more
74 * than the few instructions that the following compiles down to!
76 * The case where we don't have the xTLBEIR register really only works for
77 * MMU's with a single way and is hard-coded that way.
80 #define flush_dtlb_page_eir(addr) mtspr(SPR_DTLBEIR, addr)
81 #define flush_dtlb_page_no_eir(addr) \
82 mtspr_off(SPR_DTLBMR_BASE(0), DTLB_OFFSET(addr), 0);
84 #define flush_itlb_page_eir(addr) mtspr(SPR_ITLBEIR, addr)
85 #define flush_itlb_page_no_eir(addr) \
86 mtspr_off(SPR_ITLBMR_BASE(0), ITLB_OFFSET(addr), 0);
88 void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
91 flush_dtlb_page_eir(addr);
93 flush_dtlb_page_no_eir(addr);
96 flush_itlb_page_eir(addr);
98 flush_itlb_page_no_eir(addr);
101 void local_flush_tlb_range(struct vm_area_struct *vma,
102 unsigned long start, unsigned long end)
108 dtlbeir = have_dtlbeir;
109 itlbeir = have_itlbeir;
111 for (addr = start; addr < end; addr += PAGE_SIZE) {
113 flush_dtlb_page_eir(addr);
115 flush_dtlb_page_no_eir(addr);
118 flush_itlb_page_eir(addr);
120 flush_itlb_page_no_eir(addr);
125 * Invalidate the selected mm context only.
127 * FIXME: Due to some bug here, we're flushing everything for now.
128 * This should be changed to loop over over mm and call flush_tlb_range.
131 void local_flush_tlb_mm(struct mm_struct *mm)
134 /* Was seeing bugs with the mm struct passed to us. Scrapped most of
136 /* Several architctures do this */
137 local_flush_tlb_all();
140 /* called in schedule() just before actually doing the switch_to */
142 void switch_mm(struct mm_struct *prev, struct mm_struct *next,
143 struct task_struct *next_tsk)
145 /* remember the pgd for the fault handlers
146 * this is similar to the pgd register in some other CPU's.
147 * we need our own copy of it because current and active_mm
148 * might be invalid at points where we still need to derefer
151 current_pgd[smp_processor_id()] = next->pgd;
153 /* We don't have context support implemented, so flush all
154 * entries belonging to previous map
158 local_flush_tlb_mm(prev);
163 * Initialize the context related info for a new mm_struct
167 int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
169 mm->context = NO_CONTEXT;
173 /* called by __exit_mm to destroy the used MMU context if any before
174 * destroying the mm itself. this is only called when the last user of the mm
178 void destroy_context(struct mm_struct *mm)
184 /* called once during VM initialization, from init.c */
186 void __init tlb_init(void)
189 /* invalidate the entire TLB */
190 /* flush_tlb_all(); */