1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
|
/*
* This file contains the routines for flushing entries from the
* TLB and MMU hash table.
*
* Derived from arch/ppc64/mm/init.c:
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
*
* Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
* and Cort Dougan (PReP) (cort@cs.nmt.edu)
* Copyright (C) 1996 Paul Mackerras
* Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
*
* Derived from "arch/i386/mm/init.c"
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
*
* Dave Engebretsen <engebret@us.ibm.com>
* Rework for PPC64 port.
*
* 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/config.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/percpu.h>
#include <linux/hardirq.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include <asm/tlb.h>
#include <linux/highmem.h>
DEFINE_PER_CPU(struct ppc64_tlb_batch, ppc64_tlb_batch);
/* This is declared as we are using the more or less generic
* include/asm-ppc64/tlb.h file -- tgall
*/
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
DEFINE_PER_CPU(struct pte_freelist_batch *, pte_freelist_cur);
unsigned long pte_freelist_forced_free;
struct pte_freelist_batch
{
struct rcu_head rcu;
unsigned int index;
pgtable_free_t tables[0];
};
DEFINE_PER_CPU(struct pte_freelist_batch *, pte_freelist_cur);
unsigned long pte_freelist_forced_free;
#define PTE_FREELIST_SIZE \
((PAGE_SIZE - sizeof(struct pte_freelist_batch)) \
/ sizeof(pgtable_free_t))
#ifdef CONFIG_SMP
static void pte_free_smp_sync(void *arg)
{
/* Do nothing, just ensure we sync with all CPUs */
}
#endif
/* This is only called when we are critically out of memory
* (and fail to get a page in pte_free_tlb).
*/
static void pgtable_free_now(pgtable_free_t pgf)
{
pte_freelist_forced_free++;
smp_call_function(pte_free_smp_sync, NULL, 0, 1);
pgtable_free(pgf);
}
static void pte_free_rcu_callback(struct rcu_head *head)
{
struct pte_freelist_batch *batch =
container_of(head, struct pte_freelist_batch, rcu);
unsigned int i;
for (i = 0; i < batch->index; i++)
pgtable_free(batch->tables[i]);
free_page((unsigned long)batch);
}
static void pte_free_submit(struct pte_freelist_batch *batch)
{
INIT_RCU_HEAD(&batch->rcu);
call_rcu(&batch->rcu, pte_free_rcu_callback);
}
void pgtable_free_tlb(struct mmu_gather *tlb, pgtable_free_t pgf)
{
/* This is safe as we are holding page_table_lock */
cpumask_t local_cpumask = cpumask_of_cpu(smp_processor_id());
struct pte_freelist_batch **batchp = &__get_cpu_var(pte_freelist_cur);
if (atomic_read(&tlb->mm->mm_users) < 2 ||
cpus_equal(tlb->mm->cpu_vm_mask, local_cpumask)) {
pgtable_free(pgf);
return;
}
if (*batchp == NULL) {
*batchp = (struct pte_freelist_batch *)__get_free_page(GFP_ATOMIC);
if (*batchp == NULL) {
pgtable_free_now(pgf);
return;
}
(*batchp)->index = 0;
}
(*batchp)->tables[(*batchp)->index++] = pgf;
if ((*batchp)->index == PTE_FREELIST_SIZE) {
pte_free_submit(*batchp);
*batchp = NULL;
}
}
/*
* Update the MMU hash table to correspond with a change to
* a Linux PTE. If wrprot is true, it is permissible to
* change the existing HPTE to read-only rather than removing it
* (if we remove it we should clear the _PTE_HPTEFLAGS bits).
*/
void hpte_update(struct mm_struct *mm, unsigned long addr,
unsigned long pte, int wrprot)
{
int i;
unsigned long context = 0;
struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
if (REGION_ID(addr) == USER_REGION_ID)
context = mm->context.id;
i = batch->index;
/*
* This can happen when we are in the middle of a TLB batch and
* we encounter memory pressure (eg copy_page_range when it tries
* to allocate a new pte). If we have to reclaim memory and end
* up scanning and resetting referenced bits then our batch context
* will change mid stream.
*/
if (unlikely(i != 0 && context != batch->context)) {
flush_tlb_pending();
i = 0;
}
if (i == 0) {
batch->context = context;
batch->mm = mm;
}
batch->pte[i] = __pte(pte);
batch->addr[i] = addr;
batch->index = ++i;
if (i >= PPC64_TLB_BATCH_NR)
flush_tlb_pending();
}
void __flush_tlb_pending(struct ppc64_tlb_batch *batch)
{
int i;
int cpu;
cpumask_t tmp;
int local = 0;
BUG_ON(in_interrupt());
cpu = get_cpu();
i = batch->index;
tmp = cpumask_of_cpu(cpu);
if (cpus_equal(batch->mm->cpu_vm_mask, tmp))
local = 1;
if (i == 1)
flush_hash_page(batch->context, batch->addr[0], batch->pte[0],
local);
else
flush_hash_range(batch->context, i, local);
batch->index = 0;
put_cpu();
}
void pte_free_finish(void)
{
/* This is safe as we are holding page_table_lock */
struct pte_freelist_batch **batchp = &__get_cpu_var(pte_freelist_cur);
if (*batchp == NULL)
return;
pte_free_submit(*batchp);
*batchp = NULL;
}
|
