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 *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
15 *
16 *  Derived from "arch/i386/mm/init.c"
17 *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
18 *
19 *  This program is free software; you can redistribute it and/or
20 *  modify it under the terms of the GNU General Public License
21 *  as published by the Free Software Foundation; either version
22 *  2 of the License, or (at your option) any later version.
23 *
24 */
25
26#include <linux/kernel.h>
27#include <linux/mm.h>
28#include <linux/init.h>
29#include <linux/highmem.h>
30#include <asm/tlbflush.h>
31#include <asm/tlb.h>
32
33#include "mmu_decl.h"
34
35/*
36 * Called when unmapping pages to flush entries from the TLB/hash table.
37 */
38void flush_hash_entry(struct mm_struct *mm, pte_t *ptep, unsigned long addr)
39{
40	unsigned long ptephys;
41
42	if (Hash != 0) {
43		ptephys = __pa(ptep) & PAGE_MASK;
44		flush_hash_pages(mm->context.id, addr, ptephys, 1);
45	}
46}
47
48/*
49 * Called by ptep_set_access_flags, must flush on CPUs for which the
50 * DSI handler can't just "fixup" the TLB on a write fault
51 */
52void flush_tlb_page_nohash(struct vm_area_struct *vma, unsigned long addr)
53{
54	if (Hash != 0)
55		return;
56	_tlbie(addr);
57}
58
59/*
60 * Called at the end of a mmu_gather operation to make sure the
61 * TLB flush is completely done.
62 */
63void tlb_flush(struct mmu_gather *tlb)
64{
65	if (Hash == 0) {
66		/*
67		 * 603 needs to flush the whole TLB here since
68		 * it doesn't use a hash table.
69		 */
70		_tlbia();
71	}
72}
73
74/*
75 * TLB flushing:
76 *
77 *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
78 *  - flush_tlb_page(vma, vmaddr) flushes one page
79 *  - flush_tlb_range(vma, start, end) flushes a range of pages
80 *  - flush_tlb_kernel_range(start, end) flushes kernel pages
81 *
82 * since the hardware hash table functions as an extension of the
83 * tlb as far as the linux tables are concerned, flush it too.
84 *    -- Cort
85 */
86
87/*
88 * 750 SMP is a Bad Idea because the 750 doesn't broadcast all
89 * the cache operations on the bus.  Hence we need to use an IPI
90 * to get the other CPU(s) to invalidate their TLBs.
91 */
92#ifdef CONFIG_SMP_750
93#define FINISH_FLUSH	smp_send_tlb_invalidate(0)
94#else
95#define FINISH_FLUSH	do { } while (0)
96#endif
97
98static void flush_range(struct mm_struct *mm, unsigned long start,
99			unsigned long end)
100{
101	pmd_t *pmd;
102	unsigned long pmd_end;
103	int count;
104	unsigned int ctx = mm->context.id;
105
106	if (Hash == 0) {
107		_tlbia();
108		return;
109	}
110	start &= PAGE_MASK;
111	if (start >= end)
112		return;
113	end = (end - 1) | ~PAGE_MASK;
114	pmd = pmd_offset(pud_offset(pgd_offset(mm, start), start), start);
115	for (;;) {
116		pmd_end = ((start + PGDIR_SIZE) & PGDIR_MASK) - 1;
117		if (pmd_end > end)
118			pmd_end = end;
119		if (!pmd_none(*pmd)) {
120			count = ((pmd_end - start) >> PAGE_SHIFT) + 1;
121			flush_hash_pages(ctx, start, pmd_val(*pmd), count);
122		}
123		if (pmd_end == end)
124			break;
125		start = pmd_end + 1;
126		++pmd;
127	}
128}
129
130/*
131 * Flush kernel TLB entries in the given range
132 */
133void flush_tlb_kernel_range(unsigned long start, unsigned long end)
134{
135	flush_range(&init_mm, start, end);
136	FINISH_FLUSH;
137}
138
139/*
140 * Flush all the (user) entries for the address space described by mm.
141 */
142void flush_tlb_mm(struct mm_struct *mm)
143{
144	struct vm_area_struct *mp;
145
146	if (Hash == 0) {
147		_tlbia();
148		return;
149	}
150
151	/*
152	 * It is safe to go down the mm's list of vmas when called
153	 * from dup_mmap, holding mmap_sem.  It would also be safe from
154	 * unmap_region or exit_mmap, but not from vmtruncate on SMP -
155	 * but it seems dup_mmap is the only SMP case which gets here.
156	 */
157	for (mp = mm->mmap; mp != NULL; mp = mp->vm_next)
158		flush_range(mp->vm_mm, mp->vm_start, mp->vm_end);
159	FINISH_FLUSH;
160}
161
162void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
163{
164	struct mm_struct *mm;
165	pmd_t *pmd;
166
167	if (Hash == 0) {
168		_tlbie(vmaddr);
169		return;
170	}
171	mm = (vmaddr < TASK_SIZE)? vma->vm_mm: &init_mm;
172	pmd = pmd_offset(pud_offset(pgd_offset(mm, vmaddr), vmaddr), vmaddr);
173	if (!pmd_none(*pmd))
174		flush_hash_pages(mm->context.id, vmaddr, pmd_val(*pmd), 1);
175	FINISH_FLUSH;
176}
177
178/*
179 * For each address in the range, find the pte for the address
180 * and check _PAGE_HASHPTE bit; if it is set, find and destroy
181 * the corresponding HPTE.
182 */
183void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
184		     unsigned long end)
185{
186	flush_range(vma->vm_mm, start, end);
187	FINISH_FLUSH;
188}
189