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
212
213
214
215
216
217
218
219
220
221
222
223
224
|
/*
* Low-level SPU handling
*
* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
*
* Author: Arnd Bergmann <arndb@de.ibm.com>
*
* 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, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <asm/spu.h>
#include <asm/spu_csa.h>
#include "spufs.h"
/*
* This ought to be kept in sync with the powerpc specific do_page_fault
* function. Currently, there are a few corner cases that we haven't had
* to handle fortunately.
*/
static int spu_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
unsigned long dsisr, unsigned *flt)
{
struct vm_area_struct *vma;
unsigned long is_write;
int ret;
#if 0
if (!IS_VALID_EA(ea)) {
return -EFAULT;
}
#endif /* XXX */
if (mm == NULL) {
return -EFAULT;
}
if (mm->pgd == NULL) {
return -EFAULT;
}
down_read(&mm->mmap_sem);
vma = find_vma(mm, ea);
if (!vma)
goto bad_area;
if (vma->vm_start <= ea)
goto good_area;
if (!(vma->vm_flags & VM_GROWSDOWN))
goto bad_area;
if (expand_stack(vma, ea))
goto bad_area;
good_area:
is_write = dsisr & MFC_DSISR_ACCESS_PUT;
if (is_write) {
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
} else {
if (dsisr & MFC_DSISR_ACCESS_DENIED)
goto bad_area;
if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
goto bad_area;
}
ret = 0;
*flt = handle_mm_fault(mm, vma, ea, is_write);
switch (*flt) {
case VM_FAULT_MINOR:
current->min_flt++;
break;
case VM_FAULT_MAJOR:
current->maj_flt++;
break;
case VM_FAULT_SIGBUS:
ret = -EFAULT;
goto bad_area;
case VM_FAULT_OOM:
ret = -ENOMEM;
goto bad_area;
default:
BUG();
}
up_read(&mm->mmap_sem);
return ret;
bad_area:
up_read(&mm->mmap_sem);
return -EFAULT;
}
static void spufs_handle_dma_error(struct spu_context *ctx,
unsigned long ea, int type)
{
if (ctx->flags & SPU_CREATE_EVENTS_ENABLED) {
ctx->event_return |= type;
wake_up_all(&ctx->stop_wq);
} else {
siginfo_t info;
memset(&info, 0, sizeof(info));
switch (type) {
case SPE_EVENT_INVALID_DMA:
info.si_signo = SIGBUS;
info.si_code = BUS_OBJERR;
break;
case SPE_EVENT_SPE_DATA_STORAGE:
info.si_signo = SIGBUS;
info.si_addr = (void __user *)ea;
info.si_code = BUS_ADRERR;
break;
case SPE_EVENT_DMA_ALIGNMENT:
info.si_signo = SIGBUS;
/* DAR isn't set for an alignment fault :( */
info.si_code = BUS_ADRALN;
break;
case SPE_EVENT_SPE_ERROR:
info.si_signo = SIGILL;
info.si_addr = (void __user *)(unsigned long)
ctx->ops->npc_read(ctx) - 4;
info.si_code = ILL_ILLOPC;
break;
}
if (info.si_signo)
force_sig_info(info.si_signo, &info, current);
}
}
void spufs_dma_callback(struct spu *spu, int type)
{
spufs_handle_dma_error(spu->ctx, spu->dar, type);
}
EXPORT_SYMBOL_GPL(spufs_dma_callback);
/*
* bottom half handler for page faults, we can't do this from
* interrupt context, since we might need to sleep.
* we also need to give up the mutex so we can get scheduled
* out while waiting for the backing store.
*
* TODO: try calling hash_page from the interrupt handler first
* in order to speed up the easy case.
*/
int spufs_handle_class1(struct spu_context *ctx)
{
u64 ea, dsisr, access;
unsigned long flags;
unsigned flt = 0;
int ret;
/*
* dar and dsisr get passed from the registers
* to the spu_context, to this function, but not
* back to the spu if it gets scheduled again.
*
* if we don't handle the fault for a saved context
* in time, we can still expect to get the same fault
* the immediately after the context restore.
*/
if (ctx->state == SPU_STATE_RUNNABLE) {
ea = ctx->spu->dar;
dsisr = ctx->spu->dsisr;
ctx->spu->dar= ctx->spu->dsisr = 0;
} else {
ea = ctx->csa.priv1.mfc_dar_RW;
dsisr = ctx->csa.priv1.mfc_dsisr_RW;
ctx->csa.priv1.mfc_dar_RW = 0;
ctx->csa.priv1.mfc_dsisr_RW = 0;
}
if (!(dsisr & (MFC_DSISR_PTE_NOT_FOUND | MFC_DSISR_ACCESS_DENIED)))
return 0;
spuctx_switch_state(ctx, SPUCTX_UTIL_IOWAIT);
pr_debug("ctx %p: ea %016lx, dsisr %016lx state %d\n", ctx, ea,
dsisr, ctx->state);
ctx->stats.hash_flt++;
/* we must not hold the lock when entering spu_handle_mm_fault */
spu_release(ctx);
access = (_PAGE_PRESENT | _PAGE_USER);
access |= (dsisr & MFC_DSISR_ACCESS_PUT) ? _PAGE_RW : 0UL;
local_irq_save(flags);
ret = hash_page(ea, access, 0x300);
local_irq_restore(flags);
/* hashing failed, so try the actual fault handler */
if (ret)
ret = spu_handle_mm_fault(current->mm, ea, dsisr, &flt);
spu_acquire(ctx);
/*
* If we handled the fault successfully and are in runnable
* state, restart the DMA.
* In case of unhandled error report the problem to user space.
*/
if (!ret) {
if (flt == VM_FAULT_MINOR)
ctx->stats.min_flt++;
else
ctx->stats.maj_flt++;
if (ctx->spu)
ctx->ops->restart_dma(ctx);
} else
spufs_handle_dma_error(ctx, ea, SPE_EVENT_SPE_DATA_STORAGE);
spuctx_switch_state(ctx, SPUCTX_UTIL_SYSTEM);
return ret;
}
EXPORT_SYMBOL_GPL(spufs_handle_class1);
|
