arch/powerpc/cpu/mpc8xx/bedbug_860.c

   1 /*
   2  * Bedbug Functions specific to the MPC860 chip
   3  */
   4
   5 #include <common.h>
   6 #include <command.h>
   7 #include <linux/ctype.h>
   8 #include <bedbug/bedbug.h>
   9 #include <bedbug/regs.h>
  10 #include <bedbug/ppc.h>
  11 #include <bedbug/type.h>
  12
  13 #if defined(CONFIG_CMD_BEDBUG) && defined(CONFIG_8xx)
  14
  15 #define MAX_BREAK_POINTS 2
  16
  17 extern CPU_DEBUG_CTX bug_ctx;
  18
  19 void bedbug860_init __P((void));
  20 void bedbug860_do_break __P((cmd_tbl_t*,int,int,char*const[]));
  21 void bedbug860_break_isr __P((struct pt_regs*));
  22 int  bedbug860_find_empty __P((void));
  23 int  bedbug860_set __P((int,unsigned long));
  24 int  bedbug860_clear __P((int));
  25
  26 \f
  27 /* ======================================================================
  28  * Initialize the global bug_ctx structure for the MPC860.  Clear all
  29  * of the breakpoints.
  30  * ====================================================================== */
  31
  32 void bedbug860_init( void )
  33 {
  34   int   i;
  35   /* -------------------------------------------------- */
  36
  37   bug_ctx.hw_debug_enabled = 0;
  38   bug_ctx.stopped = 0;
  39   bug_ctx.current_bp = 0;
  40   bug_ctx.regs = NULL;
  41
  42   bug_ctx.do_break   = bedbug860_do_break;
  43   bug_ctx.break_isr  = bedbug860_break_isr;
  44   bug_ctx.find_empty = bedbug860_find_empty;
  45   bug_ctx.set        = bedbug860_set;
  46   bug_ctx.clear      = bedbug860_clear;
  47
  48   for( i = 1; i <= MAX_BREAK_POINTS; ++i )
  49     (*bug_ctx.clear)( i );
  50
  51   puts ("BEDBUG:ready\n");
  52   return;
  53 } /* bedbug_init_breakpoints */
  54
  55
  56 \f
  57 /* ======================================================================
  58  * Set/clear/show one of the hardware breakpoints for the 860.  The "off"
  59  * string will disable a specific breakpoint.  The "show" string will
  60  * display the current breakpoints.  Otherwise an address will set a
  61  * breakpoint at that address.  Setting a breakpoint uses the CPU-specific
  62  * set routine which will assign a breakpoint number.
  63  * ====================================================================== */
  64
  65 void bedbug860_do_break (cmd_tbl_t *cmdtp, int flag, int argc,
  66                          char * const argv[])
  67 {
  68   long          addr = 0;       /* Address to break at  */
  69   int           which_bp;       /* Breakpoint number    */
  70   /* -------------------------------------------------- */
  71
  72   if (argc < 2)
  73     return cmd_usage(cmdtp);
  74
  75   /* Turn off a breakpoint */
  76
  77   if( strcmp( argv[ 1 ], "off" ) == 0 )
  78   {
  79     if( bug_ctx.hw_debug_enabled == 0 )
  80     {
  81       printf( "No breakpoints enabled\n" );
  82       return;
  83     }
  84
  85     which_bp = simple_strtoul( argv[ 2 ], NULL, 10 );
  86
  87     if( bug_ctx.clear )
  88       (*bug_ctx.clear)( which_bp );
  89
  90     printf( "Breakpoint %d removed\n", which_bp );
  91     return;
  92   }
  93
  94   /* Show a list of breakpoints */
  95
  96   if( strcmp( argv[ 1 ], "show" ) == 0 )
  97   {
  98     for( which_bp = 1; which_bp <= MAX_BREAK_POINTS; ++which_bp )
  99     {
 100
 101       switch( which_bp )
 102       {
 103       case 1: addr = GET_CMPA(); break;
 104       case 2: addr = GET_CMPB(); break;
 105       case 3: addr = GET_CMPC(); break;
 106       case 4: addr = GET_CMPD(); break;
 107       }
 108
 109       printf( "Breakpoint [%d]: ", which_bp );
 110       if( addr == 0 )
 111         printf( "NOT SET\n" );
 112       else
 113         disppc( (unsigned char *)addr, 0, 1, bedbug_puts, F_RADHEX );
 114     }
 115     return;
 116   }
 117
 118   /* Set a breakpoint at the address */
 119
 120   if( !isdigit( argv[ 1 ][ 0 ]))
 121     return cmd_usage(cmdtp);
 122
 123   addr = simple_strtoul( argv[ 1 ], NULL, 16 ) & 0xfffffffc;
 124
 125   if(( bug_ctx.set ) && ( which_bp = (*bug_ctx.set)( 0, addr )) > 0 )
 126   {
 127     printf( "Breakpoint [%d]: ", which_bp );
 128     disppc( (unsigned char *)addr, 0, 1, bedbug_puts, F_RADHEX );
 129   }
 130
 131   return;
 132 } /* bedbug860_do_break */
 133
 134
 135 \f
 136 /* ======================================================================
 137  * Handle a breakpoint.  First determine which breakpoint was hit by
 138  * looking at the DeBug Status Register (DBSR), clear the breakpoint
 139  * and enter a mini main loop.  Stay in the loop until the stopped flag
 140  * in the debug context is cleared.
 141  * ====================================================================== */
 142
 143 void bedbug860_break_isr( struct pt_regs *regs )
 144 {
 145   unsigned long addr;     /* Address stopped at   */
 146   unsigned long cause;     /* Address stopped at   */
 147   /* -------------------------------------------------- */
 148
 149   cause = GET_ICR();
 150
 151   if( !(cause & 0x00000004)) {
 152     printf( "Not an instruction breakpoint (ICR 0x%08lx)\n", cause );
 153     return;
 154   }
 155
 156   addr = regs->nip;
 157
 158   if( addr == GET_CMPA() )
 159   {
 160     bug_ctx.current_bp = 1;
 161   }
 162   else if( addr == GET_CMPB() )
 163   {
 164     bug_ctx.current_bp = 2;
 165   }
 166   else if( addr == GET_CMPC() )
 167   {
 168     bug_ctx.current_bp = 3;
 169   }
 170   else if( addr == GET_CMPD() )
 171   {
 172     bug_ctx.current_bp = 4;
 173   }
 174
 175   bedbug_main_loop( addr, regs );
 176   return;
 177 } /* bedbug860_break_isr */
 178
 179
 180 \f
 181 /* ======================================================================
 182  * Look through all of the hardware breakpoints available to see if one
 183  * is unused.
 184  * ====================================================================== */
 185
 186 int bedbug860_find_empty( void )
 187 {
 188   /* -------------------------------------------------- */
 189
 190   if( GET_CMPA() == 0 )
 191     return 1;
 192
 193   if( GET_CMPB() == 0 )
 194     return 2;
 195
 196   if( GET_CMPC() == 0 )
 197     return 3;
 198
 199   if( GET_CMPD() == 0 )
 200     return 4;
 201
 202   return 0;
 203 } /* bedbug860_find_empty */
 204
 205
 206 \f
 207 /* ======================================================================
 208  * Set a breakpoint.  If 'which_bp' is zero then find an unused breakpoint
 209  * number, otherwise reassign the given breakpoint.  If hardware debugging
 210  * is not enabled, then turn it on via the MSR and DBCR0.  Set the break
 211  * address in the appropriate IACx register and enable proper address
 212  * beakpoint in DBCR0.
 213  * ====================================================================== */
 214
 215 int bedbug860_set( int which_bp, unsigned long addr )
 216 {
 217   /* -------------------------------------------------- */
 218
 219   /* Only look if which_bp == 0, else use which_bp */
 220   if(( bug_ctx.find_empty ) && ( !which_bp ) &&
 221      ( which_bp = (*bug_ctx.find_empty)()) == 0 )
 222   {
 223     printf( "All breakpoints in use\n" );
 224     return 0;
 225   }
 226
 227   if( which_bp < 1 || which_bp > MAX_BREAK_POINTS )
 228   {
 229     printf( "Invalid break point # %d\n", which_bp );
 230     return 0;
 231   }
 232
 233   if( ! bug_ctx.hw_debug_enabled )
 234   {
 235     bug_ctx.hw_debug_enabled = 1;
 236     SET_DER( GET_DER() | 0x00000004 );
 237   }
 238
 239   switch( which_bp )
 240   {
 241   case 1:
 242     SET_CMPA( addr );
 243     SET_ICTRL( GET_ICTRL() | 0x80080800 ); /* CTA=Equal,IW0=Match A,SIW0EN */
 244     break;
 245
 246   case 2:
 247     SET_CMPB( addr );
 248     SET_ICTRL( GET_ICTRL() | 0x10020400 ); /* CTB=Equal,IW1=Match B,SIW1EN */
 249     break;
 250
 251   case 3:
 252     SET_CMPC( addr );
 253     SET_ICTRL( GET_ICTRL() | 0x02008200 ); /* CTC=Equal,IW2=Match C,SIW2EN */
 254     break;
 255
 256   case 4:
 257     SET_CMPD( addr );
 258     SET_ICTRL( GET_ICTRL() | 0x00404100 ); /* CTD=Equal,IW3=Match D,SIW3EN */
 259     break;
 260   }
 261
 262   return which_bp;
 263 } /* bedbug860_set */
 264
 265
 266 \f
 267 /* ======================================================================
 268  * Disable a specific breakoint by setting the appropriate IACx register
 269  * to zero and claring the instruction address breakpoint in DBCR0.
 270  * ====================================================================== */
 271
 272 int bedbug860_clear( int which_bp )
 273 {
 274   /* -------------------------------------------------- */
 275
 276   if( which_bp < 1 || which_bp > MAX_BREAK_POINTS )
 277   {
 278     printf( "Invalid break point # (%d)\n", which_bp );
 279     return -1;
 280   }
 281
 282   switch( which_bp )
 283   {
 284   case 1:
 285     SET_CMPA( 0 );
 286     SET_ICTRL( GET_ICTRL() & ~0x80080800 ); /* CTA=Equal,IW0=Match A,SIW0EN */
 287     break;
 288
 289   case 2:
 290     SET_CMPB( 0 );
 291     SET_ICTRL( GET_ICTRL() & ~0x10020400 ); /* CTB=Equal,IW1=Match B,SIW1EN */
 292     break;
 293
 294   case 3:
 295     SET_CMPC( 0 );
 296     SET_ICTRL( GET_ICTRL() & ~0x02008200 ); /* CTC=Equal,IW2=Match C,SIW2EN */
 297     break;
 298
 299   case 4:
 300     SET_CMPD( 0 );
 301     SET_ICTRL( GET_ICTRL() & ~0x00404100 ); /* CTD=Equal,IW3=Match D,SIW3EN */
 302     break;
 303   }
 304
 305   return 0;
 306 } /* bedbug860_clear */
 307
 308
 309 /* ====================================================================== */
 310 #endif