1 | /****************************************************************************** |
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2 | * console.c |
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3 | * |
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4 | * Emergency console I/O for Xen and the domain-0 guest OS. |
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5 | * |
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6 | * Copyright (c) 2002-2004, K A Fraser. |
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7 | * |
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8 | * Added printf_ratelimit |
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9 | * Taken from Linux - Author: Andi Kleen (net_ratelimit) |
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10 | * Ported to Xen - Steven Rostedt - Red Hat |
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11 | */ |
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12 | |
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13 | #include <xen/stdarg.h> |
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14 | #include <xen/config.h> |
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15 | #include <xen/version.h> |
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16 | #include <xen/init.h> |
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17 | #include <xen/lib.h> |
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18 | #include <xen/errno.h> |
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19 | #include <xen/event.h> |
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20 | #include <xen/spinlock.h> |
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21 | #include <xen/console.h> |
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22 | #include <xen/serial.h> |
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23 | #include <xen/softirq.h> |
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24 | #include <xen/keyhandler.h> |
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25 | #include <xen/mm.h> |
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26 | #include <xen/delay.h> |
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27 | #include <xen/guest_access.h> |
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28 | #include <xen/shutdown.h> |
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29 | #include <xen/vga.h> |
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30 | #include <xen/kexec.h> |
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31 | #include <asm/current.h> |
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32 | #include <asm/debugger.h> |
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33 | #include <asm/io.h> |
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34 | #include <asm/div64.h> |
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35 | |
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36 | /* console: comma-separated list of console outputs. */ |
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37 | static char opt_console[30] = OPT_CONSOLE_STR; |
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38 | string_param("console", opt_console); |
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39 | |
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40 | /* conswitch: a character pair controlling console switching. */ |
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41 | /* Char 1: CTRL+<char1> is used to switch console input between Xen and DOM0 */ |
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42 | /* Char 2: If this character is 'x', then do not auto-switch to DOM0 when it */ |
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43 | /* boots. Any other value, or omitting the char, enables auto-switch */ |
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44 | static unsigned char opt_conswitch[5] = "a"; |
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45 | string_param("conswitch", opt_conswitch); |
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46 | |
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47 | /* sync_console: force synchronous console output (useful for debugging). */ |
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48 | static int opt_sync_console; |
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49 | boolean_param("sync_console", opt_sync_console); |
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50 | |
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51 | /* console_to_ring: send guest (incl. dom 0) console data to console ring. */ |
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52 | static int opt_console_to_ring; |
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53 | boolean_param("console_to_ring", opt_console_to_ring); |
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54 | |
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55 | #define CONRING_SIZE 16384 |
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56 | #define CONRING_IDX_MASK(i) ((i)&(CONRING_SIZE-1)) |
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57 | static char conring[CONRING_SIZE]; |
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58 | static unsigned int conringc, conringp; |
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59 | |
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60 | static char printk_prefix[16] = ""; |
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61 | |
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62 | static int sercon_handle = -1; |
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63 | |
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64 | static DEFINE_SPINLOCK(console_lock); |
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65 | |
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66 | /* |
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67 | * To control the amount of printing, thresholds are added. |
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68 | * These thresholds correspond to the XENLOG logging levels. |
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69 | * There's an upper and lower threshold for non-guest messages and for |
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70 | * guest-provoked messages. This works as follows, for a given log level L: |
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71 | * |
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72 | * L < lower_threshold : always logged |
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73 | * lower_threshold <= L < upper_threshold : rate-limited logging |
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74 | * upper_threshold <= L : never logged |
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75 | * |
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76 | * Note, in the above algorithm, to disable rate limiting simply make |
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77 | * the lower threshold equal to the upper. |
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78 | */ |
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79 | #ifdef NDEBUG |
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80 | #define XENLOG_UPPER_THRESHOLD 2 /* Do not print INFO and DEBUG */ |
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81 | #define XENLOG_LOWER_THRESHOLD 2 /* Always print ERR and WARNING */ |
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82 | #define XENLOG_GUEST_UPPER_THRESHOLD 2 /* Do not print INFO and DEBUG */ |
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83 | #define XENLOG_GUEST_LOWER_THRESHOLD 0 /* Rate-limit ERR and WARNING */ |
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84 | #else |
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85 | #define XENLOG_UPPER_THRESHOLD 4 /* Do not discard anything */ |
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86 | #define XENLOG_LOWER_THRESHOLD 4 /* Print everything */ |
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87 | #define XENLOG_GUEST_UPPER_THRESHOLD 4 /* Do not discard anything */ |
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88 | #define XENLOG_GUEST_LOWER_THRESHOLD 4 /* Print everything */ |
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89 | #endif |
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90 | /* |
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91 | * The XENLOG_DEFAULT is the default given to printks that |
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92 | * do not have any print level associated with them. |
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93 | */ |
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94 | #define XENLOG_DEFAULT 1 /* XENLOG_WARNING */ |
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95 | #define XENLOG_GUEST_DEFAULT 1 /* XENLOG_WARNING */ |
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96 | |
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97 | static int xenlog_upper_thresh = XENLOG_UPPER_THRESHOLD; |
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98 | static int xenlog_lower_thresh = XENLOG_LOWER_THRESHOLD; |
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99 | static int xenlog_guest_upper_thresh = XENLOG_GUEST_UPPER_THRESHOLD; |
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100 | static int xenlog_guest_lower_thresh = XENLOG_GUEST_LOWER_THRESHOLD; |
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101 | |
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102 | static void parse_loglvl(char *s); |
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103 | static void parse_guest_loglvl(char *s); |
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104 | |
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105 | /* |
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106 | * <lvl> := none|error|warning|info|debug|all |
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107 | * loglvl=<lvl_print_always>[/<lvl_print_ratelimit>] |
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108 | * <lvl_print_always>: log level which is always printed |
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109 | * <lvl_print_rlimit>: log level which is rate-limit printed |
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110 | * Similar definitions for guest_loglvl, but applies to guest tracing. |
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111 | * Defaults: loglvl=warning ; guest_loglvl=none/warning |
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112 | */ |
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113 | custom_param("loglvl", parse_loglvl); |
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114 | custom_param("guest_loglvl", parse_guest_loglvl); |
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115 | |
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116 | static atomic_t print_everything = ATOMIC_INIT(0); |
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117 | |
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118 | #define ___parse_loglvl(s, ps, lvlstr, lvlnum) \ |
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119 | if ( !strncmp((s), (lvlstr), strlen(lvlstr)) ) { \ |
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120 | *(ps) = (s) + strlen(lvlstr); \ |
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121 | return (lvlnum); \ |
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122 | } |
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123 | |
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124 | static int __parse_loglvl(char *s, char **ps) |
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125 | { |
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126 | ___parse_loglvl(s, ps, "none", 0); |
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127 | ___parse_loglvl(s, ps, "error", 1); |
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128 | ___parse_loglvl(s, ps, "warning", 2); |
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129 | ___parse_loglvl(s, ps, "info", 3); |
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130 | ___parse_loglvl(s, ps, "debug", 4); |
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131 | ___parse_loglvl(s, ps, "all", 4); |
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132 | return 2; /* sane fallback */ |
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133 | } |
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134 | |
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135 | static void _parse_loglvl(char *s, int *lower, int *upper) |
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136 | { |
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137 | *lower = *upper = __parse_loglvl(s, &s); |
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138 | if ( *s == '/' ) |
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139 | *upper = __parse_loglvl(s+1, &s); |
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140 | if ( *upper < *lower ) |
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141 | *upper = *lower; |
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142 | } |
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143 | |
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144 | static void parse_loglvl(char *s) |
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145 | { |
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146 | _parse_loglvl(s, &xenlog_lower_thresh, &xenlog_upper_thresh); |
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147 | } |
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148 | |
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149 | static void parse_guest_loglvl(char *s) |
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150 | { |
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151 | _parse_loglvl(s, &xenlog_guest_lower_thresh, &xenlog_guest_upper_thresh); |
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152 | } |
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153 | |
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154 | static char *loglvl_str(int lvl) |
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155 | { |
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156 | switch ( lvl ) |
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157 | { |
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158 | case 0: return "Nothing"; |
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159 | case 1: return "Errors"; |
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160 | case 2: return "Errors and warnings"; |
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161 | case 3: return "Errors, warnings and info"; |
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162 | case 4: return "All"; |
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163 | } |
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164 | return "???"; |
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165 | } |
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166 | |
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167 | /* |
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168 | * ******************************************************** |
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169 | * *************** ACCESS TO CONSOLE RING ***************** |
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170 | * ******************************************************** |
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171 | */ |
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172 | |
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173 | static void putchar_console_ring(int c) |
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174 | { |
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175 | conring[CONRING_IDX_MASK(conringp++)] = c; |
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176 | if ( (conringp - conringc) > CONRING_SIZE ) |
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177 | conringc = conringp - CONRING_SIZE; |
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178 | } |
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179 | |
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180 | long read_console_ring(XEN_GUEST_HANDLE(char) str, u32 *pcount, int clear) |
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181 | { |
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182 | unsigned int idx, len, max, sofar, c; |
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183 | unsigned long flags; |
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184 | |
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185 | max = *pcount; |
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186 | sofar = 0; |
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187 | |
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188 | c = conringc; |
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189 | while ( (c != conringp) && (sofar < max) ) |
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190 | { |
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191 | idx = CONRING_IDX_MASK(c); |
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192 | len = conringp - c; |
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193 | if ( (idx + len) > CONRING_SIZE ) |
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194 | len = CONRING_SIZE - idx; |
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195 | if ( (sofar + len) > max ) |
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196 | len = max - sofar; |
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197 | if ( copy_to_guest_offset(str, sofar, &conring[idx], len) ) |
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198 | return -EFAULT; |
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199 | sofar += len; |
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200 | c += len; |
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201 | } |
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202 | |
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203 | if ( clear ) |
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204 | { |
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205 | spin_lock_irqsave(&console_lock, flags); |
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206 | if ( (conringp - c) > CONRING_SIZE ) |
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207 | conringc = conringp - CONRING_SIZE; |
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208 | else |
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209 | conringc = c; |
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210 | spin_unlock_irqrestore(&console_lock, flags); |
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211 | } |
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212 | |
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213 | *pcount = sofar; |
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214 | return 0; |
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215 | } |
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216 | |
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217 | |
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218 | /* |
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219 | * ******************************************************* |
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220 | * *************** ACCESS TO SERIAL LINE ***************** |
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221 | * ******************************************************* |
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222 | */ |
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223 | |
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224 | /* Characters received over the serial line are buffered for domain 0. */ |
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225 | #define SERIAL_RX_SIZE 128 |
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226 | #define SERIAL_RX_MASK(_i) ((_i)&(SERIAL_RX_SIZE-1)) |
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227 | static char serial_rx_ring[SERIAL_RX_SIZE]; |
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228 | static unsigned int serial_rx_cons, serial_rx_prod; |
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229 | |
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230 | static void (*serial_steal_fn)(const char *); |
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231 | |
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232 | int console_steal(int handle, void (*fn)(const char *)) |
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233 | { |
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234 | if ( (handle == -1) || (handle != sercon_handle) ) |
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235 | return 0; |
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236 | |
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237 | if ( serial_steal_fn != NULL ) |
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238 | return -EBUSY; |
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239 | |
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240 | serial_steal_fn = fn; |
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241 | return 1; |
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242 | } |
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243 | |
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244 | void console_giveback(int id) |
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245 | { |
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246 | if ( id == 1 ) |
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247 | serial_steal_fn = NULL; |
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248 | } |
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249 | |
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250 | static void sercon_puts(const char *s) |
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251 | { |
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252 | if ( serial_steal_fn != NULL ) |
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253 | (*serial_steal_fn)(s); |
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254 | else |
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255 | serial_puts(sercon_handle, s); |
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256 | } |
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257 | |
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258 | /* CTRL-<switch_char> switches input direction between Xen and DOM0. */ |
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259 | #define SWITCH_CODE (opt_conswitch[0]-'a'+1) |
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260 | static int xen_rx = 1; /* FALSE => serial input passed to domain 0. */ |
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261 | |
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262 | static void switch_serial_input(void) |
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263 | { |
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264 | static char *input_str[2] = { "DOM0", "Xen" }; |
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265 | xen_rx = !xen_rx; |
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266 | if ( (SWITCH_CODE != 0) && (dom0 != NULL) ) |
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267 | { |
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268 | printk("*** Serial input -> %s " |
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269 | "(type 'CTRL-%c' three times to switch input to %s).\n", |
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270 | input_str[xen_rx], opt_conswitch[0], input_str[!xen_rx]); |
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271 | } |
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272 | } |
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273 | |
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274 | static void __serial_rx(char c, struct cpu_user_regs *regs) |
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275 | { |
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276 | if ( xen_rx ) |
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277 | return handle_keypress(c, regs); |
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278 | |
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279 | /* Deliver input to guest buffer, unless it is already full. */ |
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280 | if ( (serial_rx_prod-serial_rx_cons) != SERIAL_RX_SIZE ) |
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281 | serial_rx_ring[SERIAL_RX_MASK(serial_rx_prod++)] = c; |
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282 | /* Always notify the guest: prevents receive path from getting stuck. */ |
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283 | send_guest_global_virq(dom0, VIRQ_CONSOLE); |
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284 | } |
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285 | |
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286 | static void serial_rx(char c, struct cpu_user_regs *regs) |
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287 | { |
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288 | static int switch_code_count = 0; |
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289 | |
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290 | if ( (SWITCH_CODE != 0) && (c == SWITCH_CODE) ) |
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291 | { |
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292 | /* We eat CTRL-<switch_char> in groups of 3 to switch console input. */ |
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293 | if ( ++switch_code_count == 3 ) |
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294 | { |
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295 | switch_serial_input(); |
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296 | switch_code_count = 0; |
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297 | return; |
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298 | } |
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299 | } |
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300 | else |
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301 | { |
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302 | switch_code_count = 0; |
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303 | } |
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304 | |
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305 | /* Finally process the just-received character. */ |
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306 | __serial_rx(c, regs); |
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307 | } |
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308 | |
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309 | static long guest_console_write(XEN_GUEST_HANDLE(char) buffer, int count) |
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310 | { |
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311 | char kbuf[128], *kptr; |
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312 | int kcount; |
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313 | |
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314 | while ( count > 0 ) |
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315 | { |
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316 | while ( serial_tx_space(sercon_handle) < (SERIAL_TXBUFSZ / 2) ) |
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317 | { |
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318 | if ( hypercall_preempt_check() ) |
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319 | break; |
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320 | cpu_relax(); |
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321 | } |
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322 | |
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323 | if ( hypercall_preempt_check() ) |
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324 | return hypercall_create_continuation( |
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325 | __HYPERVISOR_console_io, "iih", |
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326 | CONSOLEIO_write, count, buffer); |
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327 | |
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328 | kcount = min_t(int, count, sizeof(kbuf)-1); |
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329 | if ( copy_from_guest((char *)kbuf, buffer, kcount) ) |
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330 | return -EFAULT; |
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331 | kbuf[kcount] = '\0'; |
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332 | |
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333 | sercon_puts(kbuf); |
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334 | |
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335 | for ( kptr = kbuf; *kptr != '\0'; kptr++ ) |
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336 | { |
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337 | vga_putchar(*kptr); |
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338 | if ( opt_console_to_ring ) |
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339 | putchar_console_ring(*kptr); |
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340 | } |
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341 | |
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342 | if ( opt_console_to_ring ) |
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343 | send_guest_global_virq(dom0, VIRQ_CON_RING); |
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344 | |
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345 | guest_handle_add_offset(buffer, kcount); |
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346 | count -= kcount; |
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347 | } |
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348 | |
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349 | return 0; |
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350 | } |
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351 | |
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352 | long do_console_io(int cmd, int count, XEN_GUEST_HANDLE(char) buffer) |
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353 | { |
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354 | long rc; |
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355 | unsigned int idx, len; |
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356 | |
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357 | #ifndef VERBOSE |
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358 | /* Only domain 0 may access the emergency console. */ |
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359 | if ( current->domain->domain_id != 0 ) |
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360 | return -EPERM; |
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361 | #endif |
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362 | |
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363 | switch ( cmd ) |
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364 | { |
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365 | case CONSOLEIO_write: |
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366 | rc = guest_console_write(buffer, count); |
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367 | break; |
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368 | case CONSOLEIO_read: |
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369 | rc = 0; |
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370 | while ( (serial_rx_cons != serial_rx_prod) && (rc < count) ) |
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371 | { |
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372 | idx = SERIAL_RX_MASK(serial_rx_cons); |
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373 | len = serial_rx_prod - serial_rx_cons; |
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374 | if ( (idx + len) > SERIAL_RX_SIZE ) |
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375 | len = SERIAL_RX_SIZE - idx; |
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376 | if ( (rc + len) > count ) |
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377 | len = count - rc; |
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378 | if ( copy_to_guest_offset(buffer, rc, &serial_rx_ring[idx], len) ) |
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379 | { |
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380 | rc = -EFAULT; |
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381 | break; |
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382 | } |
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383 | rc += len; |
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384 | serial_rx_cons += len; |
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385 | } |
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386 | break; |
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387 | default: |
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388 | rc = -ENOSYS; |
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389 | break; |
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390 | } |
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391 | |
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392 | return rc; |
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393 | } |
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394 | |
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395 | |
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396 | /* |
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397 | * ***************************************************** |
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398 | * *************** GENERIC CONSOLE I/O ***************** |
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399 | * ***************************************************** |
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400 | */ |
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401 | |
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402 | static void __putstr(const char *str) |
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403 | { |
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404 | int c; |
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405 | |
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406 | sercon_puts(str); |
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407 | |
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408 | while ( (c = *str++) != '\0' ) |
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409 | { |
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410 | vga_putchar(c); |
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411 | putchar_console_ring(c); |
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412 | } |
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413 | |
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414 | send_guest_global_virq(dom0, VIRQ_CON_RING); |
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415 | } |
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416 | |
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417 | static int printk_prefix_check(char *p, char **pp) |
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418 | { |
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419 | int loglvl = -1; |
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420 | int upper_thresh = xenlog_upper_thresh; |
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421 | int lower_thresh = xenlog_lower_thresh; |
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422 | |
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423 | while ( (p[0] == '<') && (p[1] != '\0') && (p[2] == '>') ) |
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424 | { |
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425 | switch ( p[1] ) |
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426 | { |
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427 | case 'G': |
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428 | upper_thresh = xenlog_guest_upper_thresh; |
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429 | lower_thresh = xenlog_guest_lower_thresh; |
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430 | if ( loglvl == -1 ) |
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431 | loglvl = XENLOG_GUEST_DEFAULT; |
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432 | break; |
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433 | case '0' ... '3': |
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434 | loglvl = p[1] - '0'; |
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435 | break; |
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436 | } |
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437 | p += 3; |
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438 | } |
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439 | |
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440 | if ( loglvl == -1 ) |
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441 | loglvl = XENLOG_DEFAULT; |
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442 | |
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443 | *pp = p; |
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444 | |
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445 | return ((atomic_read(&print_everything) != 0) || |
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446 | (loglvl < lower_thresh) || |
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447 | ((loglvl < upper_thresh) && printk_ratelimit())); |
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448 | } |
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449 | |
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450 | void printk(const char *fmt, ...) |
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451 | { |
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452 | static char buf[1024]; |
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453 | static int start_of_line = 1, do_print; |
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454 | |
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455 | va_list args; |
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456 | char *p, *q; |
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457 | unsigned long flags; |
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458 | |
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459 | /* console_lock can be acquired recursively from __printk_ratelimit(). */ |
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460 | local_irq_save(flags); |
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461 | spin_lock_recursive(&console_lock); |
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462 | |
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463 | va_start(args, fmt); |
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464 | (void)vsnprintf(buf, sizeof(buf), fmt, args); |
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465 | va_end(args); |
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466 | |
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467 | p = buf; |
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468 | |
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469 | while ( (q = strchr(p, '\n')) != NULL ) |
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470 | { |
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471 | *q = '\0'; |
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472 | if ( start_of_line ) |
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473 | do_print = printk_prefix_check(p, &p); |
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474 | if ( do_print ) |
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475 | { |
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476 | if ( start_of_line ) |
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477 | __putstr(printk_prefix); |
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478 | __putstr(p); |
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479 | __putstr("\n"); |
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480 | } |
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481 | start_of_line = 1; |
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482 | p = q + 1; |
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483 | } |
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484 | |
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485 | if ( *p != '\0' ) |
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486 | { |
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487 | if ( start_of_line ) |
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488 | do_print = printk_prefix_check(p, &p); |
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489 | if ( do_print ) |
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490 | { |
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491 | if ( start_of_line ) |
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492 | __putstr(printk_prefix); |
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493 | __putstr(p); |
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494 | } |
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495 | start_of_line = 0; |
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496 | } |
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497 | |
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498 | spin_unlock_recursive(&console_lock); |
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499 | local_irq_restore(flags); |
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500 | } |
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501 | |
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502 | void set_printk_prefix(const char *prefix) |
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503 | { |
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504 | safe_strcpy(printk_prefix, prefix); |
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505 | } |
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506 | |
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507 | void init_console(void) |
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508 | { |
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509 | char *p; |
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510 | |
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511 | /* Where should console output go? */ |
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512 | for ( p = opt_console; p != NULL; p = strchr(p, ',') ) |
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513 | { |
---|
514 | if ( *p == ',' ) |
---|
515 | p++; |
---|
516 | if ( strncmp(p, "com", 3) == 0 ) |
---|
517 | sercon_handle = serial_parse_handle(p); |
---|
518 | else if ( strncmp(p, "vga", 3) == 0 ) |
---|
519 | vga_init(); |
---|
520 | } |
---|
521 | |
---|
522 | serial_set_rx_handler(sercon_handle, serial_rx); |
---|
523 | |
---|
524 | /* HELLO WORLD --- start-of-day banner text. */ |
---|
525 | printk(xen_banner()); |
---|
526 | printk(" http://www.cl.cam.ac.uk/netos/xen\n"); |
---|
527 | printk(" University of Cambridge Computer Laboratory\n\n"); |
---|
528 | printk(" Xen version %d.%d%s (%s@%s) (%s) %s\n", |
---|
529 | xen_major_version(), xen_minor_version(), xen_extra_version(), |
---|
530 | xen_compile_by(), xen_compile_domain(), |
---|
531 | xen_compiler(), xen_compile_date()); |
---|
532 | printk(" Latest ChangeSet: %s\n\n", xen_changeset()); |
---|
533 | set_printk_prefix("(XEN) "); |
---|
534 | |
---|
535 | if ( opt_sync_console ) |
---|
536 | { |
---|
537 | serial_start_sync(sercon_handle); |
---|
538 | add_taint(TAINT_SYNC_CONSOLE); |
---|
539 | printk("Console output is synchronous.\n"); |
---|
540 | } |
---|
541 | } |
---|
542 | |
---|
543 | void console_endboot(void) |
---|
544 | { |
---|
545 | int i, j; |
---|
546 | |
---|
547 | printk("Std. Loglevel: %s", loglvl_str(xenlog_lower_thresh)); |
---|
548 | if ( xenlog_upper_thresh != xenlog_lower_thresh ) |
---|
549 | printk(" (Rate-limited: %s)", loglvl_str(xenlog_upper_thresh)); |
---|
550 | printk("\nGuest Loglevel: %s", loglvl_str(xenlog_guest_lower_thresh)); |
---|
551 | if ( xenlog_guest_upper_thresh != xenlog_guest_lower_thresh ) |
---|
552 | printk(" (Rate-limited: %s)", loglvl_str(xenlog_guest_upper_thresh)); |
---|
553 | printk("\n"); |
---|
554 | |
---|
555 | if ( opt_sync_console ) |
---|
556 | { |
---|
557 | printk("**********************************************\n"); |
---|
558 | printk("******* WARNING: CONSOLE OUTPUT IS SYNCHRONOUS\n"); |
---|
559 | printk("******* This option is intended to aid debugging " |
---|
560 | "of Xen by ensuring\n"); |
---|
561 | printk("******* that all output is synchronously delivered " |
---|
562 | "on the serial line.\n"); |
---|
563 | printk("******* However it can introduce SIGNIFICANT latencies " |
---|
564 | "and affect\n"); |
---|
565 | printk("******* timekeeping. It is NOT recommended for " |
---|
566 | "production use!\n"); |
---|
567 | printk("**********************************************\n"); |
---|
568 | for ( i = 0; i < 3; i++ ) |
---|
569 | { |
---|
570 | printk("%d... ", 3-i); |
---|
571 | for ( j = 0; j < 100; j++ ) |
---|
572 | { |
---|
573 | process_pending_timers(); |
---|
574 | mdelay(10); |
---|
575 | } |
---|
576 | } |
---|
577 | printk("\n"); |
---|
578 | } |
---|
579 | |
---|
580 | vga_endboot(); |
---|
581 | |
---|
582 | /* |
---|
583 | * If user specifies so, we fool the switch routine to redirect input |
---|
584 | * straight back to Xen. I use this convoluted method so we still print |
---|
585 | * a useful 'how to switch' message. |
---|
586 | */ |
---|
587 | if ( opt_conswitch[1] == 'x' ) |
---|
588 | xen_rx = !xen_rx; |
---|
589 | |
---|
590 | /* Serial input is directed to DOM0 by default. */ |
---|
591 | switch_serial_input(); |
---|
592 | } |
---|
593 | |
---|
594 | void console_start_log_everything(void) |
---|
595 | { |
---|
596 | atomic_inc(&print_everything); |
---|
597 | } |
---|
598 | |
---|
599 | void console_end_log_everything(void) |
---|
600 | { |
---|
601 | atomic_dec(&print_everything); |
---|
602 | } |
---|
603 | |
---|
604 | void console_force_unlock(void) |
---|
605 | { |
---|
606 | spin_lock_init(&console_lock); |
---|
607 | serial_force_unlock(sercon_handle); |
---|
608 | console_start_sync(); |
---|
609 | } |
---|
610 | |
---|
611 | void console_force_lock(void) |
---|
612 | { |
---|
613 | spin_lock(&console_lock); |
---|
614 | } |
---|
615 | |
---|
616 | void console_start_sync(void) |
---|
617 | { |
---|
618 | console_start_log_everything(); |
---|
619 | serial_start_sync(sercon_handle); |
---|
620 | } |
---|
621 | |
---|
622 | void console_end_sync(void) |
---|
623 | { |
---|
624 | serial_end_sync(sercon_handle); |
---|
625 | console_end_log_everything(); |
---|
626 | } |
---|
627 | |
---|
628 | void console_putc(char c) |
---|
629 | { |
---|
630 | serial_putc(sercon_handle, c); |
---|
631 | } |
---|
632 | |
---|
633 | int console_getc(void) |
---|
634 | { |
---|
635 | return serial_getc(sercon_handle); |
---|
636 | } |
---|
637 | |
---|
638 | /* |
---|
639 | * printk rate limiting, lifted from Linux. |
---|
640 | * |
---|
641 | * This enforces a rate limit: not more than one kernel message |
---|
642 | * every printk_ratelimit_ms (millisecs). |
---|
643 | */ |
---|
644 | int __printk_ratelimit(int ratelimit_ms, int ratelimit_burst) |
---|
645 | { |
---|
646 | static DEFINE_SPINLOCK(ratelimit_lock); |
---|
647 | static unsigned long toks = 10 * 5 * 1000; |
---|
648 | static unsigned long last_msg; |
---|
649 | static int missed; |
---|
650 | unsigned long flags; |
---|
651 | unsigned long long now = NOW(); /* ns */ |
---|
652 | unsigned long ms; |
---|
653 | |
---|
654 | do_div(now, 1000000); |
---|
655 | ms = (unsigned long)now; |
---|
656 | |
---|
657 | spin_lock_irqsave(&ratelimit_lock, flags); |
---|
658 | toks += ms - last_msg; |
---|
659 | last_msg = ms; |
---|
660 | if ( toks > (ratelimit_burst * ratelimit_ms)) |
---|
661 | toks = ratelimit_burst * ratelimit_ms; |
---|
662 | if ( toks >= ratelimit_ms ) |
---|
663 | { |
---|
664 | int lost = missed; |
---|
665 | missed = 0; |
---|
666 | toks -= ratelimit_ms; |
---|
667 | spin_unlock(&ratelimit_lock); |
---|
668 | if ( lost ) |
---|
669 | { |
---|
670 | char lost_str[8]; |
---|
671 | snprintf(lost_str, sizeof(lost_str), "%d", lost); |
---|
672 | /* console_lock may already be acquired by printk(). */ |
---|
673 | spin_lock_recursive(&console_lock); |
---|
674 | __putstr(printk_prefix); |
---|
675 | __putstr("printk: "); |
---|
676 | __putstr(lost_str); |
---|
677 | __putstr(" messages suppressed.\n"); |
---|
678 | spin_unlock_recursive(&console_lock); |
---|
679 | } |
---|
680 | local_irq_restore(flags); |
---|
681 | return 1; |
---|
682 | } |
---|
683 | missed++; |
---|
684 | spin_unlock_irqrestore(&ratelimit_lock, flags); |
---|
685 | return 0; |
---|
686 | } |
---|
687 | |
---|
688 | /* minimum time in ms between messages */ |
---|
689 | int printk_ratelimit_ms = 5 * 1000; |
---|
690 | |
---|
691 | /* number of messages we send before ratelimiting */ |
---|
692 | int printk_ratelimit_burst = 10; |
---|
693 | |
---|
694 | int printk_ratelimit(void) |
---|
695 | { |
---|
696 | return __printk_ratelimit(printk_ratelimit_ms, printk_ratelimit_burst); |
---|
697 | } |
---|
698 | |
---|
699 | /* |
---|
700 | * ************************************************************** |
---|
701 | * *************** Serial console ring buffer ******************* |
---|
702 | * ************************************************************** |
---|
703 | */ |
---|
704 | |
---|
705 | #ifdef DEBUG_TRACE_DUMP |
---|
706 | |
---|
707 | /* Send output direct to console, or buffer it? */ |
---|
708 | static volatile int debugtrace_send_to_console; |
---|
709 | |
---|
710 | static char *debugtrace_buf; /* Debug-trace buffer */ |
---|
711 | static unsigned int debugtrace_prd; /* Producer index */ |
---|
712 | static unsigned int debugtrace_kilobytes = 128, debugtrace_bytes; |
---|
713 | static unsigned int debugtrace_used; |
---|
714 | static DEFINE_SPINLOCK(debugtrace_lock); |
---|
715 | integer_param("debugtrace", debugtrace_kilobytes); |
---|
716 | |
---|
717 | static void debugtrace_dump_worker(void) |
---|
718 | { |
---|
719 | if ( (debugtrace_bytes == 0) || !debugtrace_used ) |
---|
720 | return; |
---|
721 | |
---|
722 | printk("debugtrace_dump() starting\n"); |
---|
723 | |
---|
724 | /* Print oldest portion of the ring. */ |
---|
725 | ASSERT(debugtrace_buf[debugtrace_bytes - 1] == 0); |
---|
726 | sercon_puts(&debugtrace_buf[debugtrace_prd]); |
---|
727 | |
---|
728 | /* Print youngest portion of the ring. */ |
---|
729 | debugtrace_buf[debugtrace_prd] = '\0'; |
---|
730 | sercon_puts(&debugtrace_buf[0]); |
---|
731 | |
---|
732 | memset(debugtrace_buf, '\0', debugtrace_bytes); |
---|
733 | |
---|
734 | printk("debugtrace_dump() finished\n"); |
---|
735 | } |
---|
736 | |
---|
737 | static void debugtrace_toggle(void) |
---|
738 | { |
---|
739 | unsigned long flags; |
---|
740 | |
---|
741 | watchdog_disable(); |
---|
742 | spin_lock_irqsave(&debugtrace_lock, flags); |
---|
743 | |
---|
744 | /* |
---|
745 | * Dump the buffer *before* toggling, in case the act of dumping the |
---|
746 | * buffer itself causes more printk() invocations. |
---|
747 | */ |
---|
748 | printk("debugtrace_printk now writing to %s.\n", |
---|
749 | !debugtrace_send_to_console ? "console": "buffer"); |
---|
750 | if ( !debugtrace_send_to_console ) |
---|
751 | debugtrace_dump_worker(); |
---|
752 | |
---|
753 | debugtrace_send_to_console = !debugtrace_send_to_console; |
---|
754 | |
---|
755 | spin_unlock_irqrestore(&debugtrace_lock, flags); |
---|
756 | watchdog_enable(); |
---|
757 | |
---|
758 | } |
---|
759 | |
---|
760 | void debugtrace_dump(void) |
---|
761 | { |
---|
762 | unsigned long flags; |
---|
763 | |
---|
764 | watchdog_disable(); |
---|
765 | spin_lock_irqsave(&debugtrace_lock, flags); |
---|
766 | |
---|
767 | debugtrace_dump_worker(); |
---|
768 | |
---|
769 | spin_unlock_irqrestore(&debugtrace_lock, flags); |
---|
770 | watchdog_enable(); |
---|
771 | } |
---|
772 | |
---|
773 | void debugtrace_printk(const char *fmt, ...) |
---|
774 | { |
---|
775 | static char buf[1024]; |
---|
776 | static u32 count; |
---|
777 | |
---|
778 | va_list args; |
---|
779 | char *p; |
---|
780 | unsigned long flags; |
---|
781 | |
---|
782 | if ( debugtrace_bytes == 0 ) |
---|
783 | return; |
---|
784 | |
---|
785 | debugtrace_used = 1; |
---|
786 | |
---|
787 | spin_lock_irqsave(&debugtrace_lock, flags); |
---|
788 | |
---|
789 | ASSERT(debugtrace_buf[debugtrace_bytes - 1] == 0); |
---|
790 | |
---|
791 | snprintf(buf, sizeof(buf), "%u ", ++count); |
---|
792 | |
---|
793 | va_start(args, fmt); |
---|
794 | (void)vsnprintf(buf + strlen(buf), sizeof(buf), fmt, args); |
---|
795 | va_end(args); |
---|
796 | |
---|
797 | if ( debugtrace_send_to_console ) |
---|
798 | { |
---|
799 | serial_puts(sercon_handle, buf); |
---|
800 | } |
---|
801 | else |
---|
802 | { |
---|
803 | for ( p = buf; *p != '\0'; p++ ) |
---|
804 | { |
---|
805 | debugtrace_buf[debugtrace_prd++] = *p; |
---|
806 | /* Always leave a nul byte at the end of the buffer. */ |
---|
807 | if ( debugtrace_prd == (debugtrace_bytes - 1) ) |
---|
808 | debugtrace_prd = 0; |
---|
809 | } |
---|
810 | } |
---|
811 | |
---|
812 | spin_unlock_irqrestore(&debugtrace_lock, flags); |
---|
813 | } |
---|
814 | |
---|
815 | static void debugtrace_key(unsigned char key) |
---|
816 | { |
---|
817 | debugtrace_toggle(); |
---|
818 | } |
---|
819 | |
---|
820 | static int __init debugtrace_init(void) |
---|
821 | { |
---|
822 | int order; |
---|
823 | unsigned int kbytes, bytes; |
---|
824 | |
---|
825 | /* Round size down to next power of two. */ |
---|
826 | while ( (kbytes = (debugtrace_kilobytes & (debugtrace_kilobytes-1))) != 0 ) |
---|
827 | debugtrace_kilobytes = kbytes; |
---|
828 | |
---|
829 | bytes = debugtrace_kilobytes << 10; |
---|
830 | if ( bytes == 0 ) |
---|
831 | return 0; |
---|
832 | |
---|
833 | order = get_order_from_bytes(bytes); |
---|
834 | debugtrace_buf = alloc_xenheap_pages(order); |
---|
835 | ASSERT(debugtrace_buf != NULL); |
---|
836 | |
---|
837 | memset(debugtrace_buf, '\0', bytes); |
---|
838 | |
---|
839 | debugtrace_bytes = bytes; |
---|
840 | |
---|
841 | register_keyhandler( |
---|
842 | 'T', debugtrace_key, "toggle debugtrace to console/buffer"); |
---|
843 | |
---|
844 | return 0; |
---|
845 | } |
---|
846 | __initcall(debugtrace_init); |
---|
847 | |
---|
848 | #endif /* !NDEBUG */ |
---|
849 | |
---|
850 | |
---|
851 | |
---|
852 | /* |
---|
853 | * ************************************************************** |
---|
854 | * *************** Debugging/tracing/error-report *************** |
---|
855 | * ************************************************************** |
---|
856 | */ |
---|
857 | |
---|
858 | void panic(const char *fmt, ...) |
---|
859 | { |
---|
860 | va_list args; |
---|
861 | unsigned long flags; |
---|
862 | static DEFINE_SPINLOCK(lock); |
---|
863 | static char buf[128]; |
---|
864 | |
---|
865 | debugtrace_dump(); |
---|
866 | |
---|
867 | /* Protects buf[] and ensure multi-line message prints atomically. */ |
---|
868 | spin_lock_irqsave(&lock, flags); |
---|
869 | |
---|
870 | va_start(args, fmt); |
---|
871 | (void)vsnprintf(buf, sizeof(buf), fmt, args); |
---|
872 | va_end(args); |
---|
873 | |
---|
874 | console_start_sync(); |
---|
875 | printk("\n****************************************\n"); |
---|
876 | printk("Panic on CPU %d:\n", smp_processor_id()); |
---|
877 | printk(buf); |
---|
878 | printk("****************************************\n\n"); |
---|
879 | if ( opt_noreboot ) |
---|
880 | printk("Manual reset required ('noreboot' specified)\n"); |
---|
881 | else |
---|
882 | printk("Reboot in five seconds...\n"); |
---|
883 | |
---|
884 | spin_unlock_irqrestore(&lock, flags); |
---|
885 | |
---|
886 | debugger_trap_immediate(); |
---|
887 | |
---|
888 | kexec_crash(); |
---|
889 | |
---|
890 | if ( opt_noreboot ) |
---|
891 | { |
---|
892 | machine_halt(); |
---|
893 | } |
---|
894 | else |
---|
895 | { |
---|
896 | watchdog_disable(); |
---|
897 | mdelay(5000); |
---|
898 | machine_restart(NULL); |
---|
899 | } |
---|
900 | } |
---|
901 | |
---|
902 | void __bug(char *file, int line) |
---|
903 | { |
---|
904 | console_start_sync(); |
---|
905 | printk("Xen BUG at %s:%d\n", file, line); |
---|
906 | dump_execution_state(); |
---|
907 | panic("Xen BUG at %s:%d\n", file, line); |
---|
908 | for ( ; ; ) ; |
---|
909 | } |
---|
910 | |
---|
911 | void __warn(char *file, int line) |
---|
912 | { |
---|
913 | printk("Xen WARN at %s:%d\n", file, line); |
---|
914 | dump_execution_state(); |
---|
915 | } |
---|
916 | |
---|
917 | /* |
---|
918 | * Local variables: |
---|
919 | * mode: C |
---|
920 | * c-set-style: "BSD" |
---|
921 | * c-basic-offset: 4 |
---|
922 | * tab-width: 4 |
---|
923 | * indent-tabs-mode: nil |
---|
924 | * End: |
---|
925 | */ |
---|
926 | |
---|