1 /* SPDX-License-Identifier: GPL-2.0-or-later * 1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /* 2 /*
3 * Copyright (C) 2001,2002,2003 Broadcom Corpo 3 * Copyright (C) 2001,2002,2003 Broadcom Corporation
4 */ 4 */
5 5
6 #include <asm/asm.h> 6 #include <asm/asm.h>
7 #include <asm/regdef.h> 7 #include <asm/regdef.h>
8 #include <asm/mipsregs.h> 8 #include <asm/mipsregs.h>
9 #include <asm/stackframe.h> 9 #include <asm/stackframe.h>
10 #include <asm/cacheops.h> 10 #include <asm/cacheops.h>
11 #include <asm/sibyte/board.h> 11 #include <asm/sibyte/board.h>
12 12
13 #define C0_ERRCTL $26 /* CP0: 13 #define C0_ERRCTL $26 /* CP0: Error info */
14 #define C0_CERR_I $27 /* CP0: 14 #define C0_CERR_I $27 /* CP0: Icache error */
15 #define C0_CERR_D $27,1 /* CP0: 15 #define C0_CERR_D $27,1 /* CP0: Dcache error */
16 16
17 /* 17 /*
18 * Based on SiByte sample software cac 18 * Based on SiByte sample software cache-err/cerr.S
19 * CVS revision 1.8. Only the 'unreco 19 * CVS revision 1.8. Only the 'unrecoverable' case
20 * is changed. 20 * is changed.
21 */ 21 */
22 22
23 .set mips64 23 .set mips64
24 .set noreorder 24 .set noreorder
25 .set noat 25 .set noat
26 26
27 /* 27 /*
28 * sb1_cerr_vec: code to be copied to 28 * sb1_cerr_vec: code to be copied to the Cache Error
29 * Exception vector. The code must be 29 * Exception vector. The code must be pushed out to memory
30 * (either by copying to Kseg0 and Kse 30 * (either by copying to Kseg0 and Kseg1 both, or by flushing
31 * the L1 and L2) since it is fetched 31 * the L1 and L2) since it is fetched as 0xa0000100.
32 * 32 *
33 * NOTE: Be sure this handler is at mo 33 * NOTE: Be sure this handler is at most 28 instructions long
34 * since the final 16 bytes of the exc 34 * since the final 16 bytes of the exception vector memory
35 * (0x170-0x17f) are used to preserve 35 * (0x170-0x17f) are used to preserve k0, k1, and ra.
36 */ 36 */
37 37
38 LEAF(except_vec2_sb1) 38 LEAF(except_vec2_sb1)
39 /* 39 /*
40 * If this error is recoverable, we ne 40 * If this error is recoverable, we need to exit the handler
41 * without having dirtied any register 41 * without having dirtied any registers. To do this,
42 * save/restore k0 and k1 from low mem 42 * save/restore k0 and k1 from low memory (Useg is direct
43 * mapped while ERL=1). Note that we c 43 * mapped while ERL=1). Note that we can't save to a
44 * CPU-specific location without ruini 44 * CPU-specific location without ruining a register in the
45 * process. This means we are vulnera 45 * process. This means we are vulnerable to data corruption
46 * whenever the handler is reentered b 46 * whenever the handler is reentered by a second CPU.
47 */ 47 */
48 sd k0,0x170($0) 48 sd k0,0x170($0)
49 sd k1,0x178($0) 49 sd k1,0x178($0)
50 50
51 #ifdef CONFIG_SB1_CEX_ALWAYS_FATAL 51 #ifdef CONFIG_SB1_CEX_ALWAYS_FATAL
52 j handle_vec2_sb1 52 j handle_vec2_sb1
53 nop 53 nop
54 #else 54 #else
55 /* 55 /*
56 * M_ERRCTL_RECOVERABLE is bit 31, whi 56 * M_ERRCTL_RECOVERABLE is bit 31, which makes it easy to tell
57 * if we can fast-path out of here for 57 * if we can fast-path out of here for a h/w-recovered error.
58 */ 58 */
59 mfc0 k1,C0_ERRCTL 59 mfc0 k1,C0_ERRCTL
60 bgtz k1,attempt_recovery 60 bgtz k1,attempt_recovery
61 sll k0,k1,1 61 sll k0,k1,1
62 62
63 recovered_dcache: 63 recovered_dcache:
64 /* 64 /*
65 * Unlock CacheErr-D (which in turn un 65 * Unlock CacheErr-D (which in turn unlocks CacheErr-DPA).
66 * Ought to log the occurrence of this 66 * Ought to log the occurrence of this recovered dcache error.
67 */ 67 */
68 b recovered 68 b recovered
69 mtc0 $0,C0_CERR_D 69 mtc0 $0,C0_CERR_D
70 70
71 attempt_recovery: 71 attempt_recovery:
72 /* 72 /*
73 * k0 has C0_ERRCTL << 1, which puts ' 73 * k0 has C0_ERRCTL << 1, which puts 'DC' at bit 31. Any
74 * Dcache errors we can recover from w 74 * Dcache errors we can recover from will take more extensive
75 * processing. For now, they are cons 75 * processing. For now, they are considered "unrecoverable".
76 * Note that 'DC' becoming set (outsid 76 * Note that 'DC' becoming set (outside of ERL mode) will
77 * cause 'IC' to clear; so if there's 77 * cause 'IC' to clear; so if there's an Icache error, we'll
78 * only find out about it if we recove 78 * only find out about it if we recover from this error and
79 * continue executing. 79 * continue executing.
80 */ 80 */
81 bltz k0,unrecoverable 81 bltz k0,unrecoverable
82 sll k0,1 82 sll k0,1
83 83
84 /* 84 /*
85 * k0 has C0_ERRCTL << 2, which puts ' 85 * k0 has C0_ERRCTL << 2, which puts 'IC' at bit 31. If an
86 * Icache error isn't indicated, I'm n 86 * Icache error isn't indicated, I'm not sure why we got here.
87 * Consider that case "unrecoverable" 87 * Consider that case "unrecoverable" for now.
88 */ 88 */
89 bgez k0,unrecoverable 89 bgez k0,unrecoverable
90 90
91 attempt_icache_recovery: 91 attempt_icache_recovery:
92 /* 92 /*
93 * External icache errors are due to u 93 * External icache errors are due to uncorrectable ECC errors
94 * in the L2 cache or Memory Controlle 94 * in the L2 cache or Memory Controller and cannot be
95 * recovered here. 95 * recovered here.
96 */ 96 */
97 mfc0 k0,C0_CERR_I /* del 97 mfc0 k0,C0_CERR_I /* delay slot */
98 li k1,1 << 26 /* ICA 98 li k1,1 << 26 /* ICACHE_EXTERNAL */
99 and k1,k0 99 and k1,k0
100 bnez k1,unrecoverable 100 bnez k1,unrecoverable
101 andi k0,0x1fe0 101 andi k0,0x1fe0
102 102
103 /* 103 /*
104 * Since the error is internal, the 'I 104 * Since the error is internal, the 'IDX' field from
105 * CacheErr-I is valid and we can just 105 * CacheErr-I is valid and we can just invalidate all blocks
106 * in that set. 106 * in that set.
107 */ 107 */
108 cache Index_Invalidate_I,(0<<13)(k0) 108 cache Index_Invalidate_I,(0<<13)(k0)
109 cache Index_Invalidate_I,(1<<13)(k0) 109 cache Index_Invalidate_I,(1<<13)(k0)
110 cache Index_Invalidate_I,(2<<13)(k0) 110 cache Index_Invalidate_I,(2<<13)(k0)
111 cache Index_Invalidate_I,(3<<13)(k0) 111 cache Index_Invalidate_I,(3<<13)(k0)
112 112
113 /* Ought to log this recovered icache 113 /* Ought to log this recovered icache error */
114 114
115 recovered: 115 recovered:
116 /* Restore the saved registers */ 116 /* Restore the saved registers */
117 ld k0,0x170($0) 117 ld k0,0x170($0)
118 ld k1,0x178($0) 118 ld k1,0x178($0)
119 eret 119 eret
120 120
121 unrecoverable: 121 unrecoverable:
122 /* Unrecoverable Icache or Dcache erro 122 /* Unrecoverable Icache or Dcache error; log it and/or fail */
123 j handle_vec2_sb1 123 j handle_vec2_sb1
124 nop 124 nop
125 #endif 125 #endif
126 126
127 END(except_vec2_sb1) 127 END(except_vec2_sb1)
128 128
129 LEAF(handle_vec2_sb1) 129 LEAF(handle_vec2_sb1)
130 mfc0 k0,CP0_CONFIG 130 mfc0 k0,CP0_CONFIG
131 li k1,~CONF_CM_CMASK 131 li k1,~CONF_CM_CMASK
132 and k0,k0,k1 132 and k0,k0,k1
133 ori k0,k0,CONF_CM_UNCACHED 133 ori k0,k0,CONF_CM_UNCACHED
134 mtc0 k0,CP0_CONFIG 134 mtc0 k0,CP0_CONFIG
135 135
136 SSNOP 136 SSNOP
137 SSNOP 137 SSNOP
138 SSNOP 138 SSNOP
139 SSNOP 139 SSNOP
140 bnezl $0, 1f 140 bnezl $0, 1f
141 1: 141 1:
142 mfc0 k0, CP0_STATUS 142 mfc0 k0, CP0_STATUS
143 sll k0, k0, 3 143 sll k0, k0, 3 # check CU0 (kernel?)
144 bltz k0, 2f 144 bltz k0, 2f
145 nop 145 nop
146 146
147 /* Get a valid Kseg0 stack pointer. A 147 /* Get a valid Kseg0 stack pointer. Any task's stack pointer
148 * will do, although if we ever want t 148 * will do, although if we ever want to resume execution we
149 * better not have corrupted any state 149 * better not have corrupted any state. */
150 get_saved_sp 150 get_saved_sp
151 move sp, k1 151 move sp, k1
152 152
153 2: 153 2:
154 j sb1_cache_error 154 j sb1_cache_error
155 nop 155 nop
156 156
157 END(handle_vec2_sb1) 157 END(handle_vec2_sb1)
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