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
|
/*
* MMU context allocation for 64-bit kernels.
*
* Copyright (C) 2004 Anton Blanchard, IBM Corp. <anton@samba.org>
*
* 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/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/spinlock.h>
#include <linux/idr.h>
#include <linux/export.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <asm/mmu_context.h>
#include <asm/pgalloc.h>
#include "icswx.h"
static DEFINE_SPINLOCK(mmu_context_lock);
static DEFINE_IDA(mmu_context_ida);
int __init_new_context(void)
{
int index;
int err;
again:
if (!ida_pre_get(&mmu_context_ida, GFP_KERNEL))
return -ENOMEM;
spin_lock(&mmu_context_lock);
err = ida_get_new_above(&mmu_context_ida, 1, &index);
spin_unlock(&mmu_context_lock);
if (err == -EAGAIN)
goto again;
else if (err)
return err;
if (index > MAX_USER_CONTEXT) {
spin_lock(&mmu_context_lock);
ida_remove(&mmu_context_ida, index);
spin_unlock(&mmu_context_lock);
return -ENOMEM;
}
return index;
}
EXPORT_SYMBOL_GPL(__init_new_context);
static int radix__init_new_context(struct mm_struct *mm, int index)
{
unsigned long rts_field;
/*
* set the process table entry,
*/
rts_field = radix__get_tree_size();
process_tb[index].prtb0 = cpu_to_be64(rts_field | __pa(mm->pgd) | RADIX_PGD_INDEX_SIZE);
return 0;
}
int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
{
int index;
index = __init_new_context();
if (index < 0)
return index;
if (radix_enabled()) {
radix__init_new_context(mm, index);
} else {
/* The old code would re-promote on fork, we don't do that
* when using slices as it could cause problem promoting slices
* that have been forced down to 4K
*
* For book3s we have MMU_NO_CONTEXT set to be ~0. Hence check
* explicitly against context.id == 0. This ensures that we
* properly initialize context slice details for newly allocated
* mm's (which will have id == 0) and don't alter context slice
* inherited via fork (which will have id != 0).
*
* We should not be calling init_new_context() on init_mm. Hence a
* check against 0 is ok.
*/
if (mm->context.id == 0)
slice_set_user_psize(mm, mmu_virtual_psize);
subpage_prot_init_new_context(mm);
}
mm->context.id = index;
#ifdef CONFIG_PPC_ICSWX
mm->context.cop_lockp = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
if (!mm->context.cop_lockp) {
__destroy_context(index);
subpage_prot_free(mm);
mm->context.id = MMU_NO_CONTEXT;
return -ENOMEM;
}
spin_lock_init(mm->context.cop_lockp);
#endif /* CONFIG_PPC_ICSWX */
#ifdef CONFIG_PPC_64K_PAGES
mm->context.pte_frag = NULL;
#endif
#ifdef CONFIG_SPAPR_TCE_IOMMU
mm_iommu_init(&mm->context);
#endif
return 0;
}
void __destroy_context(int context_id)
{
spin_lock(&mmu_context_lock);
ida_remove(&mmu_context_ida, context_id);
spin_unlock(&mmu_context_lock);
}
EXPORT_SYMBOL_GPL(__destroy_context);
#ifdef CONFIG_PPC_64K_PAGES
static void destroy_pagetable_page(struct mm_struct *mm)
{
int count;
void *pte_frag;
struct page *page;
pte_frag = mm->context.pte_frag;
if (!pte_frag)
return;
page = virt_to_page(pte_frag);
/* drop all the pending references */
count = ((unsigned long)pte_frag & ~PAGE_MASK) >> PTE_FRAG_SIZE_SHIFT;
/* We allow PTE_FRAG_NR fragments from a PTE page */
if (page_ref_sub_and_test(page, PTE_FRAG_NR - count)) {
pgtable_page_dtor(page);
free_hot_cold_page(page, 0);
}
}
#else
static inline void destroy_pagetable_page(struct mm_struct *mm)
{
return;
}
#endif
void destroy_context(struct mm_struct *mm)
{
#ifdef CONFIG_SPAPR_TCE_IOMMU
mm_iommu_cleanup(&mm->context);
#endif
#ifdef CONFIG_PPC_ICSWX
drop_cop(mm->context.acop, mm);
kfree(mm->context.cop_lockp);
mm->context.cop_lockp = NULL;
#endif /* CONFIG_PPC_ICSWX */
if (radix_enabled())
process_tb[mm->context.id].prtb1 = 0;
else
subpage_prot_free(mm);
destroy_pagetable_page(mm);
__destroy_context(mm->context.id);
mm->context.id = MMU_NO_CONTEXT;
}
#ifdef CONFIG_PPC_RADIX_MMU
void radix__switch_mmu_context(struct mm_struct *prev, struct mm_struct *next)
{
asm volatile("isync": : :"memory");
mtspr(SPRN_PID, next->context.id);
asm volatile("isync \n"
PPC_SLBIA(0x7)
: : :"memory");
}
#endif
|
