Blame view

kernel/linux-imx6_3.14.28/arch/mips/mm/cex-sb1.S 4.54 KB
6b13f685e   김민수   BSP 최초 추가
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
  /*
   * Copyright (C) 2001,2002,2003 Broadcom Corporation
   *
   * 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.
   *
   * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
   */
  
  #include <asm/asm.h>
  #include <asm/regdef.h>
  #include <asm/mipsregs.h>
  #include <asm/stackframe.h>
  #include <asm/cacheops.h>
  #include <asm/sibyte/board.h>
  
  #define C0_ERRCTL     $26	      /* CP0: Error info */
  #define C0_CERR_I     $27	      /* CP0: Icache error */
  #define C0_CERR_D     $27,1	      /* CP0: Dcache error */
  
  	/*
  	 * Based on SiByte sample software cache-err/cerr.S
  	 * CVS revision 1.8.  Only the 'unrecoverable' case
  	 * is changed.
  	 */
  
  	.set	mips64
  	.set	noreorder
  	.set	noat
  
  	/*
  	 * sb1_cerr_vec: code to be copied to the Cache Error
  	 * Exception vector.  The code must be pushed out to memory
  	 * (either by copying to Kseg0 and Kseg1 both, or by flushing
  	 * the L1 and L2) since it is fetched as 0xa0000100.
  	 *
  	 * NOTE: Be sure this handler is at most 28 instructions long
  	 * since the final 16 bytes of the exception vector memory
  	 * (0x170-0x17f) are used to preserve k0, k1, and ra.
  	 */
  
  LEAF(except_vec2_sb1)
  	/*
  	 * If this error is recoverable, we need to exit the handler
  	 * without having dirtied any registers.  To do this,
  	 * save/restore k0 and k1 from low memory (Useg is direct
  	 * mapped while ERL=1). Note that we can't save to a
  	 * CPU-specific location without ruining a register in the
  	 * process.  This means we are vulnerable to data corruption
  	 * whenever the handler is reentered by a second CPU.
  	 */
  	sd	k0,0x170($0)
  	sd	k1,0x178($0)
  
  #ifdef CONFIG_SB1_CEX_ALWAYS_FATAL
  	j	handle_vec2_sb1
  	 nop
  #else
  	/*
  	 * M_ERRCTL_RECOVERABLE is bit 31, which makes it easy to tell
  	 * if we can fast-path out of here for a h/w-recovered error.
  	 */
  	mfc0	k1,C0_ERRCTL
  	bgtz	k1,attempt_recovery
  	 sll	k0,k1,1
  
  recovered_dcache:
  	/*
  	 * Unlock CacheErr-D (which in turn unlocks CacheErr-DPA).
  	 * Ought to log the occurrence of this recovered dcache error.
  	 */
  	b	recovered
  	 mtc0	$0,C0_CERR_D
  
  attempt_recovery:
  	/*
  	 * k0 has C0_ERRCTL << 1, which puts 'DC' at bit 31.  Any
  	 * Dcache errors we can recover from will take more extensive
  	 * processing.	For now, they are considered "unrecoverable".
  	 * Note that 'DC' becoming set (outside of ERL mode) will
  	 * cause 'IC' to clear; so if there's an Icache error, we'll
  	 * only find out about it if we recover from this error and
  	 * continue executing.
  	 */
  	bltz	k0,unrecoverable
  	 sll	k0,1
  
  	/*
  	 * k0 has C0_ERRCTL << 2, which puts 'IC' at bit 31.  If an
  	 * Icache error isn't indicated, I'm not sure why we got here.
  	 * Consider that case "unrecoverable" for now.
  	 */
  	bgez	k0,unrecoverable
  
  attempt_icache_recovery:
  	/*
  	 * External icache errors are due to uncorrectable ECC errors
  	 * in the L2 cache or Memory Controller and cannot be
  	 * recovered here.
  	 */
  	 mfc0	k0,C0_CERR_I		/* delay slot */
  	li	k1,1 << 26		/* ICACHE_EXTERNAL */
  	and	k1,k0
  	bnez	k1,unrecoverable
  	 andi	k0,0x1fe0
  
  	/*
  	 * Since the error is internal, the 'IDX' field from
  	 * CacheErr-I is valid and we can just invalidate all blocks
  	 * in that set.
  	 */
  	cache	Index_Invalidate_I,(0<<13)(k0)
  	cache	Index_Invalidate_I,(1<<13)(k0)
  	cache	Index_Invalidate_I,(2<<13)(k0)
  	cache	Index_Invalidate_I,(3<<13)(k0)
  
  	/* Ought to log this recovered icache error */
  
  recovered:
  	/* Restore the saved registers */
  	ld	k0,0x170($0)
  	ld	k1,0x178($0)
  	eret
  
  unrecoverable:
  	/* Unrecoverable Icache or Dcache error; log it and/or fail */
  	j	handle_vec2_sb1
  	 nop
  #endif
  
  END(except_vec2_sb1)
  
  	LEAF(handle_vec2_sb1)
  	mfc0	k0,CP0_CONFIG
  	li	k1,~CONF_CM_CMASK
  	and	k0,k0,k1
  	ori	k0,k0,CONF_CM_UNCACHED
  	mtc0	k0,CP0_CONFIG
  
  	SSNOP
  	SSNOP
  	SSNOP
  	SSNOP
  	bnezl	$0, 1f
  1:
  	mfc0	k0, CP0_STATUS
  	sll	k0, k0, 3			# check CU0 (kernel?)
  	bltz	k0, 2f
  	 nop
  
  	/* Get a valid Kseg0 stack pointer.  Any task's stack pointer
  	 * will do, although if we ever want to resume execution we
  	 * better not have corrupted any state. */
  	get_saved_sp
  	move	sp, k1
  
  2:
  	j	sb1_cache_error
  	 nop
  
  	END(handle_vec2_sb1)