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
|
/****************************************************************************
* arch/arm/src/src/up_prefetchabort.c
*
* Copyright (C) 2007-2011 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <spudmonkey@racsa.co.cr>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <debug.h>
#include <nuttx/irq.h>
#ifdef CONFIG_PAGING
# include <nuttx/page.h>
#endif
#include "os_internal.h"
#include "up_internal.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Debug ********************************************************************/
/* Output debug info if stack dump is selected -- even if
* debug is not selected.
*/
#ifdef CONFIG_ARCH_STACKDUMP
# undef lldbg
# define lldbg lib_lowprintf
#endif
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: up_prefetchabort
*
* Description;
* This is the prefetch abort exception handler. The ARM prefetch abort
* exception occurs when a memory fault is detected during an an
* instruction fetch.
*
****************************************************************************/
void up_prefetchabort(uint32_t *regs)
{
#ifdef CONFIG_PAGING
uint32_t *savestate;
/* Save the saved processor context in current_regs where it can be accessed
* for register dumps and possibly context switching.
*/
savestate = (uint32_t*)current_regs;
#endif
current_regs = regs;
#ifdef CONFIG_PAGING
/* Get the (virtual) address of instruction that caused the prefetch abort.
* When the exception occurred, this address was provided in the lr register
* and this value was saved in the context save area as the PC at the
* REG_R15 index.
*
* Check to see if this miss address is within the configured range of
* virtual addresses.
*/
pglldbg("VADDR: %08x VBASE: %08x VEND: %08x\n",
regs[REG_PC], PG_PAGED_VBASE, PG_PAGED_VEND);
if (regs[REG_R15] >= PG_PAGED_VBASE && regs[REG_R15] < PG_PAGED_VEND)
{
/* Save the offending PC as the fault address in the TCB of the currently
* executing task. This value is, of course, already known in regs[REG_R15],
* but saving it in this location will allow common paging logic for both
* prefetch and data aborts.
*/
FAR _TCB *tcb = (FAR _TCB *)g_readytorun.head;
tcb->xcp.far = regs[REG_R15];
/* Call pg_miss() to schedule the page fill. A consequences of this
* call are:
*
* (1) The currently executing task will be blocked and saved on
* on the g_waitingforfill task list.
* (2) An interrupt-level context switch will occur so that when
* this function returns, it will return to a different task,
* most likely the page fill worker thread.
* (3) The page fill worker task has been signalled and should
* execute immediately when we return from this exception.
*/
pg_miss();
/* Restore the previous value of current_regs. NULL would indicate that
* we are no longer in an interrupt handler. It will be non-NULL if we
* are returning from a nested interrupt.
*/
current_regs = savestate;
}
else
#endif
{
lldbg("Prefetch abort. PC: %08x\n", regs[REG_PC]);
PANIC(OSERR_ERREXCEPTION);
}
}
|
