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
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
|
/*
* 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
*
* 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/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 <asm/bug.h>
DEFINE_PER_CPU(struct ppc64_tlb_batch, ppc64_tlb_batch);
/* This is declared as we are using the more or less generic
* arch/powerpc/include/asm/tlb.h file -- tgall
*/
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
/*
* A linux PTE was changed and the corresponding hash table entry
* neesd to be flushed. This function will either perform the flush
* immediately or will batch it up if the current CPU has an active
* batch on it.
*
* Must be called from within some kind of spinlock/non-preempt region...
*/
void hpte_need_flush(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, unsigned long pte, int huge)
{
struct ppc64_tlb_batch *batch = &__get_cpu_var(ppc64_tlb_batch);
unsigned long vsid, vaddr;
unsigned int psize;
int ssize;
real_pte_t rpte;
int i;
i = batch->index;
/* We mask the address for the base page size. Huge pages will
* have applied their own masking already
*/
addr &= PAGE_MASK;
/* Get page size (maybe move back to caller).
*
* NOTE: when using special 64K mappings in 4K environment like
* for SPEs, we obtain the page size from the slice, which thus
* must still exist (and thus the VMA not reused) at the time
* of this call
*/
if (huge) {
#ifdef CONFIG_HUGETLB_PAGE
psize = get_slice_psize(mm, addr);
#else
BUG();
psize = pte_pagesize_index(mm, addr, pte); /* shutup gcc */
#endif
} else
psize = pte_pagesize_index(mm, addr, pte);
/* Build full vaddr */
if (!is_kernel_addr(addr)) {
ssize = user_segment_size(addr);
vsid = get_vsid(mm->context.id, addr, ssize);
WARN_ON(vsid == 0);
} else {
vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
ssize = mmu_kernel_ssize;
}
vaddr = hpt_va(addr, vsid, ssize);
rpte = __real_pte(__pte(pte), ptep);
/*
* Check if we have an active batch on this CPU. If not, just
* flush now and return. For now, we don global invalidates
* in that case, might be worth testing the mm cpu mask though
* and decide to use local invalidates instead...
*/
if (!batch->active) {
flush_hash_page(vaddr, rpte, psize, ssize, 0);
return;
}
/*
* 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.
*
* We also need to ensure only one page size is present in a given
* batch
*/
if (i != 0 && (mm != batch->mm || batch->psize != psize ||
batch->ssize != ssize)) {
__flush_tlb_pending(batch);
i = 0;
}
if (i == 0) {
batch->mm = mm;
batch->psize = psize;
batch->ssize = ssize;
}
batch->pte[i] = rpte;
batch->vaddr[i] = vaddr;
batch->index = ++i;
if (i >= PPC64_TLB_BATCH_NR)
__flush_tlb_pending(batch);
}
/*
* This function is called when terminating an mmu batch or when a batch
* is full. It will perform the flush of all the entries currently stored
* in a batch.
*
* Must be called from within some kind of spinlock/non-preempt region...
*/
void __flush_tlb_pending(struct ppc64_tlb_batch *batch)
{
const struct cpumask *tmp;
int i, local = 0;
i = batch->index;
tmp = cpumask_of(smp_processor_id());
if (cpumask_equal(mm_cpumask(batch->mm), tmp))
local = 1;
if (i == 1)
flush_hash_page(batch->vaddr[0], batch->pte[0],
batch->psize, batch->ssize, local);
else
flush_hash_range(i, local);
batch->index = 0;
}
/**
* __flush_hash_table_range - Flush all HPTEs for a given address range
* from the hash table (and the TLB). But keeps
* the linux PTEs intact.
*
* @mm : mm_struct of the target address space (generally init_mm)
* @start : starting address
* @end : ending address (not included in the flush)
*
* This function is mostly to be used by some IO hotplug code in order
* to remove all hash entries from a given address range used to map IO
* space on a removed PCI-PCI bidge without tearing down the full mapping
* since 64K pages may overlap with other bridges when using 64K pages
* with 4K HW pages on IO space.
*
* Because of that usage pattern, it's only available with CONFIG_HOTPLUG
* and is implemented for small size rather than speed.
*/
#ifdef CONFIG_HOTPLUG
void __flush_hash_table_range(struct mm_struct *mm, unsigned long start,
unsigned long end)
{
unsigned long flags;
start = _ALIGN_DOWN(start, PAGE_SIZE);
end = _ALIGN_UP(end, PAGE_SIZE);
BUG_ON(!mm->pgd);
/* Note: Normally, we should only ever use a batch within a
* PTE locked section. This violates the rule, but will work
* since we don't actually modify the PTEs, we just flush the
* hash while leaving the PTEs intact (including their reference
* to being hashed). This is not the most performance oriented
* way to do things but is fine for our needs here.
*/
local_irq_save(flags);
arch_enter_lazy_mmu_mode();
for (; start < end; start += PAGE_SIZE) {
pte_t *ptep = find_linux_pte(mm->pgd, start);
unsigned long pte;
if (ptep == NULL)
continue;
pte = pte_val(*ptep);
if (!(pte & _PAGE_HASHPTE))
continue;
hpte_need_flush(mm, start, ptep, pte, 0);
}
arch_leave_lazy_mmu_mode();
local_irq_restore(flags);
}
#endif /* CONFIG_HOTPLUG */
|
