LXR linux/arch/sparc/kernel/kgdb

   1// SPDX-License-Identifier: GPL-2.0
   2/* kgdb.c: KGDB support for 32-bit sparc.
   3 *
   4 * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
   5 */
   6
   7#include <linux/kgdb.h>
   8#include <linux/kdebug.h>
   9#include <linux/sched.h>
  10
  11#include <asm/kdebug.h>
  12#include <asm/ptrace.h>
  13#include <asm/irq.h>
  14#include <asm/cacheflush.h>
  15
  16#include "kernel.h"
  17#include "entry.h"
  18
  19void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  20{
  21        struct reg_window32 *win;
  22        int i;
  23
  24        gdb_regs[GDB_G0] = 0;
  25        for (i = 0; i < 15; i++)
  26                gdb_regs[GDB_G1 + i] = regs->u_regs[UREG_G1 + i];
  27
  28        win = (struct reg_window32 *) regs->u_regs[UREG_FP];
  29        for (i = 0; i < 8; i++)
  30                gdb_regs[GDB_L0 + i] = win->locals[i];
  31        for (i = 0; i < 8; i++)
  32                gdb_regs[GDB_I0 + i] = win->ins[i];
  33
  34        for (i = GDB_F0; i <= GDB_F31; i++)
  35                gdb_regs[i] = 0;
  36
  37        gdb_regs[GDB_Y] = regs->y;
  38        gdb_regs[GDB_PSR] = regs->psr;
  39        gdb_regs[GDB_WIM] = 0;
  40        gdb_regs[GDB_TBR] = (unsigned long) &trapbase;
  41        gdb_regs[GDB_PC] = regs->pc;
  42        gdb_regs[GDB_NPC] = regs->npc;
  43        gdb_regs[GDB_FSR] = 0;
  44        gdb_regs[GDB_CSR] = 0;
  45}
  46
  47void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
  48{
  49        struct thread_info *t = task_thread_info(p);
  50        struct reg_window32 *win;
  51        int i;
  52
  53        for (i = GDB_G0; i < GDB_G6; i++)
  54                gdb_regs[i] = 0;
  55        gdb_regs[GDB_G6] = (unsigned long) t;
  56        gdb_regs[GDB_G7] = 0;
  57        for (i = GDB_O0; i < GDB_SP; i++)
  58                gdb_regs[i] = 0;
  59        gdb_regs[GDB_SP] = t->ksp;
  60        gdb_regs[GDB_O7] = 0;
  61
  62        win = (struct reg_window32 *) t->ksp;
  63        for (i = 0; i < 8; i++)
  64                gdb_regs[GDB_L0 + i] = win->locals[i];
  65        for (i = 0; i < 8; i++)
  66                gdb_regs[GDB_I0 + i] = win->ins[i];
  67
  68        for (i = GDB_F0; i <= GDB_F31; i++)
  69                gdb_regs[i] = 0;
  70
  71        gdb_regs[GDB_Y] = 0;
  72
  73        gdb_regs[GDB_PSR] = t->kpsr;
  74        gdb_regs[GDB_WIM] = t->kwim;
  75        gdb_regs[GDB_TBR] = (unsigned long) &trapbase;
  76        gdb_regs[GDB_PC] = t->kpc;
  77        gdb_regs[GDB_NPC] = t->kpc + 4;
  78        gdb_regs[GDB_FSR] = 0;
  79        gdb_regs[GDB_CSR] = 0;
  80}
  81
  82void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
  83{
  84        struct reg_window32 *win;
  85        int i;
  86
  87        for (i = 0; i < 15; i++)
  88                regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i];
  89
  90        /* If the PSR register is changing, we have to preserve
  91         * the CWP field, otherwise window save/restore explodes.
  92         */
  93        if (regs->psr != gdb_regs[GDB_PSR]) {
  94                unsigned long cwp = regs->psr & PSR_CWP;
  95
  96                regs->psr = (gdb_regs[GDB_PSR] & ~PSR_CWP) | cwp;
  97        }
  98
  99        regs->pc = gdb_regs[GDB_PC];
 100        regs->npc = gdb_regs[GDB_NPC];
 101        regs->y = gdb_regs[GDB_Y];
 102
 103        win = (struct reg_window32 *) regs->u_regs[UREG_FP];
 104        for (i = 0; i < 8; i++)
 105                win->locals[i] = gdb_regs[GDB_L0 + i];
 106        for (i = 0; i < 8; i++)
 107                win->ins[i] = gdb_regs[GDB_I0 + i];
 108}
 109
 110int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
 111                               char *remcomInBuffer, char *remcomOutBuffer,
 112                               struct pt_regs *linux_regs)
 113{
 114        unsigned long addr;
 115        char *ptr;
 116
 117        switch (remcomInBuffer[0]) {
 118        case 'c':
 119                /* try to read optional parameter, pc unchanged if no parm */
 120                ptr = &remcomInBuffer[1];
 121                if (kgdb_hex2long(&ptr, &addr)) {
 122                        linux_regs->pc = addr;
 123                        linux_regs->npc = addr + 4;
 124                }
 125                fallthrough;
 126
 127        case 'D':
 128        case 'k':
 129                if (linux_regs->pc == (unsigned long) arch_kgdb_breakpoint) {
 130                        linux_regs->pc = linux_regs->npc;
 131                        linux_regs->npc += 4;
 132                }
 133                return 0;
 134        }
 135        return -1;
 136}
 137
 138asmlinkage void kgdb_trap(unsigned long trap_level, struct pt_regs *regs)
 139{
 140        unsigned long flags;
 141
 142        if (user_mode(regs)) {
 143                do_hw_interrupt(regs, trap_level);
 144                return;
 145        }
 146
 147        flushw_all();
 148
 149        local_irq_save(flags);
 150        kgdb_handle_exception(trap_level, 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
 169const struct kgdb_arch arch_kgdb_ops = {
 170        /* Breakpoint instruction: ta 0x7d */
 171        .gdb_bpt_instr          = { 0x91, 0xd0, 0x20, 0x7d },
 172};
 173