LXR linux/arch/sparc/kernel/kgdb

   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#include <linux/sched.h>
   9
  10#include <asm/kdebug.h>
  11#include <asm/ptrace.h>
  12#include <asm/irq.h>
  13#include <asm/cacheflush.h>
  14
  15extern unsigned long trapbase;
  16
  17void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  18{
  19        struct reg_window32 *win;
  20        int i;
  21
  22        gdb_regs[GDB_G0] = 0;
  23        for (i = 0; i < 15; i++)
  24                gdb_regs[GDB_G1 + i] = regs->u_regs[UREG_G1 + i];
  25
  26        win = (struct reg_window32 *) regs->u_regs[UREG_FP];
  27        for (i = 0; i < 8; i++)
  28                gdb_regs[GDB_L0 + i] = win->locals[i];
  29        for (i = 0; i < 8; i++)
  30                gdb_regs[GDB_I0 + i] = win->ins[i];
  31
  32        for (i = GDB_F0; i <= GDB_F31; i++)
  33                gdb_regs[i] = 0;
  34
  35        gdb_regs[GDB_Y] = regs->y;
  36        gdb_regs[GDB_PSR] = regs->psr;
  37        gdb_regs[GDB_WIM] = 0;
  38        gdb_regs[GDB_TBR] = (unsigned long) &trapbase;
  39        gdb_regs[GDB_PC] = regs->pc;
  40        gdb_regs[GDB_NPC] = regs->npc;
  41        gdb_regs[GDB_FSR] = 0;
  42        gdb_regs[GDB_CSR] = 0;
  43}
  44
  45void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
  46{
  47        struct thread_info *t = task_thread_info(p);
  48        struct reg_window32 *win;
  49        int i;
  50
  51        for (i = GDB_G0; i < GDB_G6; i++)
  52                gdb_regs[i] = 0;
  53        gdb_regs[GDB_G6] = (unsigned long) t;
  54        gdb_regs[GDB_G7] = 0;
  55        for (i = GDB_O0; i < GDB_SP; i++)
  56                gdb_regs[i] = 0;
  57        gdb_regs[GDB_SP] = t->ksp;
  58        gdb_regs[GDB_O7] = 0;
  59
  60        win = (struct reg_window32 *) t->ksp;
  61        for (i = 0; i < 8; i++)
  62                gdb_regs[GDB_L0 + i] = win->locals[i];
  63        for (i = 0; i < 8; i++)
  64                gdb_regs[GDB_I0 + i] = win->ins[i];
  65
  66        for (i = GDB_F0; i <= GDB_F31; i++)
  67                gdb_regs[i] = 0;
  68
  69        gdb_regs[GDB_Y] = 0;
  70
  71        gdb_regs[GDB_PSR] = t->kpsr;
  72        gdb_regs[GDB_WIM] = t->kwim;
  73        gdb_regs[GDB_TBR] = (unsigned long) &trapbase;
  74        gdb_regs[GDB_PC] = t->kpc;
  75        gdb_regs[GDB_NPC] = t->kpc + 4;
  76        gdb_regs[GDB_FSR] = 0;
  77        gdb_regs[GDB_CSR] = 0;
  78}
  79
  80void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  81{
  82        struct reg_window32 *win;
  83        int i;
  84
  85        for (i = 0; i < 15; i++)
  86                regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i];
  87
  88        /* If the PSR register is changing, we have to preserve
  89         * the CWP field, otherwise window save/restore explodes.
  90         */
  91        if (regs->psr != gdb_regs[GDB_PSR]) {
  92                unsigned long cwp = regs->psr & PSR_CWP;
  93
  94                regs->psr = (gdb_regs[GDB_PSR] & ~PSR_CWP) | cwp;
  95        }
  96
  97        regs->pc = gdb_regs[GDB_PC];
  98        regs->npc = gdb_regs[GDB_NPC];
  99        regs->y = gdb_regs[GDB_Y];
 100
 101        win = (struct reg_window32 *) regs->u_regs[UREG_FP];
 102        for (i = 0; i < 8; i++)
 103                win->locals[i] = gdb_regs[GDB_L0 + i];
 104        for (i = 0; i < 8; i++)
 105                win->ins[i] = gdb_regs[GDB_I0 + i];
 106}
 107
 108int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
 109                               char *remcomInBuffer, char *remcomOutBuffer,
 110                               struct pt_regs *linux_regs)
 111{
 112        unsigned long addr;
 113        char *ptr;
 114
 115        switch (remcomInBuffer[0]) {
 116        case 'c':
 117                /* try to read optional parameter, pc unchanged if no parm */
 118                ptr = &remcomInBuffer[1];
 119                if (kgdb_hex2long(&ptr, &addr)) {
 120                        linux_regs->pc = addr;
 121                        linux_regs->npc = addr + 4;
 122                }
 123                /* fallthru */
 124
 125        case 'D':
 126        case 'k':
 127                if (linux_regs->pc == (unsigned long) arch_kgdb_breakpoint) {
 128                        linux_regs->pc = linux_regs->npc;
 129                        linux_regs->npc += 4;
 130                }
 131                return 0;
 132        }
 133        return -1;
 134}
 135
 136extern void do_hw_interrupt(struct pt_regs *regs, unsigned long type);
 137
 138asmlinkage void kgdb_trap(struct pt_regs *regs)
 139{
 140        unsigned long flags;
 141
 142        if (user_mode(regs)) {
 143                do_hw_interrupt(regs, 0xfd);
 144                return;
 145        }
 146
 147        flushw_all();
 148
 149        local_irq_save(flags);
 150        kgdb_handle_exception(0x172, SIGTRAP, 0, regs);
 151        local_irq_restore(flags);
 152}
 153
 154int kgdb_arch_init(void)
 155{
 156        return 0;
 157}
 158
 159void kgdb_arch_exit(void)
 160{
 161}
 162
 163void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
 164{
 165        regs->pc = ip;
 166        regs->npc = regs->pc + 4;
 167}
 168
 169struct kgdb_arch arch_kgdb_ops = {
 170        /* Breakpoint instruction: ta 0x7d */
 171        .gdb_bpt_instr          = { 0x91, 0xd0, 0x20, 0x7d },
 172};
 173