linux/arch/sparc/kernel/kgdb.c
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   1/* kgdb.c: KGDB support for 32-bit sparc.
   2 *
   3 * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
   4 */
   5
   6#include <linux/kgdb.h>
   7#include <linux/kdebug.h>
   8
   9#include <asm/kdebug.h>
  10#include <asm/ptrace.h>
  11#include <asm/irq.h>
  12
  13extern unsigned long trapbase;
  14
  15void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  16{
  17        struct reg_window *win;
  18        int i;
  19
  20        gdb_regs[GDB_G0] = 0;
  21        for (i = 0; i < 15; i++)
  22                gdb_regs[GDB_G1 + i] = regs->u_regs[UREG_G1 + i];
  23
  24        win = (struct reg_window *) regs->u_regs[UREG_FP];
  25        for (i = 0; i < 8; i++)
  26                gdb_regs[GDB_L0 + i] = win->locals[i];
  27        for (i = 0; i < 8; i++)
  28                gdb_regs[GDB_I0 + i] = win->ins[i];
  29
  30        for (i = GDB_F0; i <= GDB_F31; i++)
  31                gdb_regs[i] = 0;
  32
  33        gdb_regs[GDB_Y] = regs->y;
  34        gdb_regs[GDB_PSR] = regs->psr;
  35        gdb_regs[GDB_WIM] = 0;
  36        gdb_regs[GDB_TBR] = (unsigned long) &trapbase;
  37        gdb_regs[GDB_PC] = regs->pc;
  38        gdb_regs[GDB_NPC] = regs->npc;
  39        gdb_regs[GDB_FSR] = 0;
  40        gdb_regs[GDB_CSR] = 0;
  41}
  42
  43void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
  44{
  45        struct thread_info *t = task_thread_info(p);
  46        struct reg_window *win;
  47        int i;
  48
  49        for (i = GDB_G0; i < GDB_G6; i++)
  50                gdb_regs[i] = 0;
  51        gdb_regs[GDB_G6] = (unsigned long) t;
  52        gdb_regs[GDB_G7] = 0;
  53        for (i = GDB_O0; i < GDB_SP; i++)
  54                gdb_regs[i] = 0;
  55        gdb_regs[GDB_SP] = t->ksp;
  56        gdb_regs[GDB_O7] = 0;
  57
  58        win = (struct reg_window *) t->ksp;
  59        for (i = 0; i < 8; i++)
  60                gdb_regs[GDB_L0 + i] = win->locals[i];
  61        for (i = 0; i < 8; i++)
  62                gdb_regs[GDB_I0 + i] = win->ins[i];
  63
  64        for (i = GDB_F0; i <= GDB_F31; i++)
  65                gdb_regs[i] = 0;
  66
  67        gdb_regs[GDB_Y] = 0;
  68
  69        gdb_regs[GDB_PSR] = t->kpsr;
  70        gdb_regs[GDB_WIM] = t->kwim;
  71        gdb_regs[GDB_TBR] = (unsigned long) &trapbase;
  72        gdb_regs[GDB_PC] = t->kpc;
  73        gdb_regs[GDB_NPC] = t->kpc + 4;
  74        gdb_regs[GDB_FSR] = 0;
  75        gdb_regs[GDB_CSR] = 0;
  76}
  77
  78void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  79{
  80        struct reg_window *win;
  81        int i;
  82
  83        for (i = 0; i < 15; i++)
  84                regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i];
  85
  86        /* If the PSR register is changing, we have to preserve
  87         * the CWP field, otherwise window save/restore explodes.
  88         */
  89        if (regs->psr != gdb_regs[GDB_PSR]) {
  90                unsigned long cwp = regs->psr & PSR_CWP;
  91
  92                regs->psr = (gdb_regs[GDB_PSR] & ~PSR_CWP) | cwp;
  93        }
  94
  95        regs->pc = gdb_regs[GDB_PC];
  96        regs->npc = gdb_regs[GDB_NPC];
  97        regs->y = gdb_regs[GDB_Y];
  98
  99        win = (struct reg_window *) regs->u_regs[UREG_FP];
 100        for (i = 0; i < 8; i++)
 101                win->locals[i] = gdb_regs[GDB_L0 + i];
 102        for (i = 0; i < 8; i++)
 103                win->ins[i] = gdb_regs[GDB_I0 + i];
 104}
 105
 106int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
 107                               char *remcomInBuffer, char *remcomOutBuffer,
 108                               struct pt_regs *linux_regs)
 109{
 110        unsigned long addr;
 111        char *ptr;
 112
 113        switch (remcomInBuffer[0]) {
 114        case 'c':
 115                /* try to read optional parameter, pc unchanged if no parm */
 116                ptr = &remcomInBuffer[1];
 117                if (kgdb_hex2long(&ptr, &addr)) {
 118                        linux_regs->pc = addr;
 119                        linux_regs->npc = addr + 4;
 120                }
 121                /* fallthru */
 122
 123        case 'D':
 124        case 'k':
 125                if (linux_regs->pc == (unsigned long) arch_kgdb_breakpoint) {
 126                        linux_regs->pc = linux_regs->npc;
 127                        linux_regs->npc += 4;
 128                }
 129                return 0;
 130        }
 131        return -1;
 132}
 133
 134extern void do_hw_interrupt(struct pt_regs *regs, unsigned long type);
 135
 136asmlinkage void kgdb_trap(struct pt_regs *regs)
 137{
 138        unsigned long flags;
 139
 140        if (user_mode(regs)) {
 141                do_hw_interrupt(regs, 0xfd);
 142                return;
 143        }
 144
 145        flushw_all();
 146
 147        local_irq_save(flags);
 148        kgdb_handle_exception(0x172, SIGTRAP, 0, regs);
 149        local_irq_restore(flags);
 150}
 151
 152int kgdb_arch_init(void)
 153{
 154        return 0;
 155}
 156
 157void kgdb_arch_exit(void)
 158{
 159}
 160
 161struct kgdb_arch arch_kgdb_ops = {
 162        /* Breakpoint instruction: ta 0x7d */
 163        .gdb_bpt_instr          = { 0x91, 0xd0, 0x20, 0x7d },
 164};
 165