1/*
2 * This file contains the routines for TLB flushing.
3 * On machines where the MMU uses a hash table to store virtual to
4 * physical translations, these routines flush entries from the
5 * hash table also.
6 *  -- paulus
7 *
8 *  Derived from arch/ppc/mm/init.c:
9 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
10 *
11 *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
12 *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
13 *    Copyright (C) 1996 Paul Mackerras
14 *
15 *  Derived from "arch/i386/mm/init.c"
16 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
17 *
18 *  This program is free software; you can redistribute it and/or
19 *  modify it under the terms of the GNU General Public License
20 *  as published by the Free Software Foundation; either version
21 *  2 of the License, or (at your option) any later version.
22 *
23 */
24
25#include <linux/kernel.h>
26#include <linux/mm.h>
27#include <linux/init.h>
28#include <linux/highmem.h>
29#include <linux/pagemap.h>
30#include <linux/export.h>
31
32#include <asm/tlbflush.h>
33#include <asm/tlb.h>
34
35#include "mmu_decl.h"
36
37/*
38 * Called when unmapping pages to flush entries from the TLB/hash table.
39 */
40void flush_hash_entry(struct mm_struct *mm, pte_t *ptep, unsigned long addr)
41{
42	unsigned long ptephys;
43
44	if (Hash != 0) {
45		ptephys = __pa(ptep) & PAGE_MASK;
46		flush_hash_pages(mm->context.id, addr, ptephys, 1);
47	}
48}
49EXPORT_SYMBOL(flush_hash_entry);
50
51/*
52 * Called by ptep_set_access_flags, must flush on CPUs for which the
53 * DSI handler can't just "fixup" the TLB on a write fault
54 */
55void flush_tlb_page_nohash(struct vm_area_struct *vma, unsigned long addr)
56{
57	if (Hash != 0)
58		return;
59	_tlbie(addr);
60}
61
62/*
63 * Called at the end of a mmu_gather operation to make sure the
64 * TLB flush is completely done.
65 */
66void tlb_flush(struct mmu_gather *tlb)
67{
68	if (Hash == 0) {
69		/*
70		 * 603 needs to flush the whole TLB here since
71		 * it doesn't use a hash table.
72		 */
73		_tlbia();
74	}
75}
76
77/*
78 * TLB flushing:
79 *
80 *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
81 *  - flush_tlb_page(vma, vmaddr) flushes one page
82 *  - flush_tlb_range(vma, start, end) flushes a range of pages
83 *  - flush_tlb_kernel_range(start, end) flushes kernel pages
84 *
85 * since the hardware hash table functions as an extension of the
86 * tlb as far as the linux tables are concerned, flush it too.
87 *    -- Cort
88 */
89
90static void flush_range(struct mm_struct *mm, unsigned long start,
91			unsigned long end)
92{
93	pmd_t *pmd;
94	unsigned long pmd_end;
95	int count;
96	unsigned int ctx = mm->context.id;
97
98	if (Hash == 0) {
99		_tlbia();
100		return;
101	}
102	start &= PAGE_MASK;
103	if (start >= end)
104		return;
105	end = (end - 1) | ~PAGE_MASK;
106	pmd = pmd_offset(pud_offset(pgd_offset(mm, start), start), start);
107	for (;;) {
108		pmd_end = ((start + PGDIR_SIZE) & PGDIR_MASK) - 1;
109		if (pmd_end > end)
110			pmd_end = end;
111		if (!pmd_none(*pmd)) {
112			count = ((pmd_end - start) >> PAGE_SHIFT) + 1;
113			flush_hash_pages(ctx, start, pmd_val(*pmd), count);
114		}
115		if (pmd_end == end)
116			break;
117		start = pmd_end + 1;
118		++pmd;
119	}
120}
121
122/*
123 * Flush kernel TLB entries in the given range
124 */
125void flush_tlb_kernel_range(unsigned long start, unsigned long end)
126{
127	flush_range(&init_mm, start, end);
128}
129EXPORT_SYMBOL(flush_tlb_kernel_range);
130
131/*
132 * Flush all the (user) entries for the address space described by mm.
133 */
134void flush_tlb_mm(struct mm_struct *mm)
135{
136	struct vm_area_struct *mp;
137
138	if (Hash == 0) {
139		_tlbia();
140		return;
141	}
142
143	/*
144	 * It is safe to go down the mm's list of vmas when called
145	 * from dup_mmap, holding mmap_sem.  It would also be safe from
146	 * unmap_region or exit_mmap, but not from vmtruncate on SMP -
147	 * but it seems dup_mmap is the only SMP case which gets here.
148	 */
149	for (mp = mm->mmap; mp != NULL; mp = mp->vm_next)
150		flush_range(mp->vm_mm, mp->vm_start, mp->vm_end);
151}
152EXPORT_SYMBOL(flush_tlb_mm);
153
154void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
155{
156	struct mm_struct *mm;
157	pmd_t *pmd;
158
159	if (Hash == 0) {
160		_tlbie(vmaddr);
161		return;
162	}
163	mm = (vmaddr < TASK_SIZE)? vma->vm_mm: &init_mm;
164	pmd = pmd_offset(pud_offset(pgd_offset(mm, vmaddr), vmaddr), vmaddr);
165	if (!pmd_none(*pmd))
166		flush_hash_pages(mm->context.id, vmaddr, pmd_val(*pmd), 1);
167}
168EXPORT_SYMBOL(flush_tlb_page);
169
170/*
171 * For each address in the range, find the pte for the address
172 * and check _PAGE_HASHPTE bit; if it is set, find and destroy
173 * the corresponding HPTE.
174 */
175void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
176		     unsigned long end)
177{
178	flush_range(vma->vm_mm, start, end);
179}
180EXPORT_SYMBOL(flush_tlb_range);
181
182void __init early_init_mmu(void)
183{
184}
185