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// SPDX-License-Identifier: GPL-2.0
/* kgdb.c: KGDB support for 64-bit sparc.
*
* Copyright (C) 2008 David S. Miller <davem@davemloft.net>
*/
#include <linux/kgdb.h>
#include <linux/kdebug.h>
#include <linux/ftrace.h>
#include <linux/context_tracking.h>
#include <asm/cacheflush.h>
#include <asm/kdebug.h>
#include <asm/ptrace.h>
#include <asm/irq.h>
#include "kernel.h"
void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
{
struct reg_window *win;
int i;
gdb_regs[GDB_G0] = 0;
for (i = 0; i < 15; i++)
gdb_regs[GDB_G1 + i] = regs->u_regs[UREG_G1 + i];
win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS);
for (i = 0; i < 8; i++)
gdb_regs[GDB_L0 + i] = win->locals[i];
for (i = 0; i < 8; i++)
gdb_regs[GDB_I0 + i] = win->ins[i];
for (i = GDB_F0; i <= GDB_F62; i++)
gdb_regs[i] = 0;
gdb_regs[GDB_PC] = regs->tpc;
gdb_regs[GDB_NPC] = regs->tnpc;
gdb_regs[GDB_STATE] = regs->tstate;
gdb_regs[GDB_FSR] = 0;
gdb_regs[GDB_FPRS] = 0;
gdb_regs[GDB_Y] = regs->y;
}
void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
{
struct thread_info *t = task_thread_info(p);
extern unsigned int switch_to_pc;
extern unsigned int ret_from_fork;
struct reg_window *win;
unsigned long pc, cwp;
int i;
for (i = GDB_G0; i < GDB_G6; i++)
gdb_regs[i] = 0;
gdb_regs[GDB_G6] = (unsigned long) t;
gdb_regs[GDB_G7] = (unsigned long) p;
for (i = GDB_O0; i < GDB_SP; i++)
gdb_regs[i] = 0;
gdb_regs[GDB_SP] = t->ksp;
gdb_regs[GDB_O7] = 0;
win = (struct reg_window *) (t->ksp + STACK_BIAS);
for (i = 0; i < 8; i++)
gdb_regs[GDB_L0 + i] = win->locals[i];
for (i = 0; i < 8; i++)
gdb_regs[GDB_I0 + i] = win->ins[i];
for (i = GDB_F0; i <= GDB_F62; i++)
gdb_regs[i] = 0;
if (t->new_child)
pc = (unsigned long) &ret_from_fork;
else
pc = (unsigned long) &switch_to_pc;
gdb_regs[GDB_PC] = pc;
gdb_regs[GDB_NPC] = pc + 4;
cwp = __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP];
gdb_regs[GDB_STATE] = (TSTATE_PRIV | TSTATE_IE | cwp);
gdb_regs[GDB_FSR] = 0;
gdb_regs[GDB_FPRS] = 0;
gdb_regs[GDB_Y] = 0;
}
void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
{
struct reg_window *win;
int i;
for (i = 0; i < 15; i++)
regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i];
/* If the TSTATE register is changing, we have to preserve
* the CWP field, otherwise window save/restore explodes.
*/
if (regs->tstate != gdb_regs[GDB_STATE]) {
unsigned long cwp = regs->tstate & TSTATE_CWP;
regs->tstate = (gdb_regs[GDB_STATE] & ~TSTATE_CWP) | cwp;
}
regs->tpc = gdb_regs[GDB_PC];
regs->tnpc = gdb_regs[GDB_NPC];
regs->y = gdb_regs[GDB_Y];
win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS);
for (i = 0; i < 8; i++)
win->locals[i] = gdb_regs[GDB_L0 + i];
for (i = 0; i < 8; i++)
win->ins[i] = gdb_regs[GDB_I0 + i];
}
#ifdef CONFIG_SMP
void __irq_entry smp_kgdb_capture_client(int irq, struct pt_regs *regs)
{
unsigned long flags;
__asm__ __volatile__("rdpr %%pstate, %0\n\t"
"wrpr %0, %1, %%pstate"
: "=r" (flags)
: "i" (PSTATE_IE));
flushw_all();
if (atomic_read(&kgdb_active) != -1)
kgdb_nmicallback(raw_smp_processor_id(), regs);
__asm__ __volatile__("wrpr %0, 0, %%pstate"
: : "r" (flags));
}
#endif
int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
char *remcomInBuffer, char *remcomOutBuffer,
struct pt_regs *linux_regs)
{
unsigned long addr;
char *ptr;
switch (remcomInBuffer[0]) {
case 'c':
/* try to read optional parameter, pc unchanged if no parm */
ptr = &remcomInBuffer[1];
if (kgdb_hex2long(&ptr, &addr)) {
linux_regs->tpc = addr;
linux_regs->tnpc = addr + 4;
}
/* fall through */
case 'D':
case 'k':
if (linux_regs->tpc == (unsigned long) arch_kgdb_breakpoint) {
linux_regs->tpc = linux_regs->tnpc;
linux_regs->tnpc += 4;
}
return 0;
}
return -1;
}
asmlinkage void kgdb_trap(unsigned long trap_level, struct pt_regs *regs)
{
enum ctx_state prev_state = exception_enter();
unsigned long flags;
if (user_mode(regs)) {
bad_trap(regs, trap_level);
goto out;
}
flushw_all();
local_irq_save(flags);
kgdb_handle_exception(0x172, SIGTRAP, 0, regs);
local_irq_restore(flags);
out:
exception_exit(prev_state);
}
int kgdb_arch_init(void)
{
return 0;
}
void kgdb_arch_exit(void)
{
}
void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
{
regs->tpc = ip;
regs->tnpc = regs->tpc + 4;
}
const struct kgdb_arch arch_kgdb_ops = {
/* Breakpoint instruction: ta 0x72 */
.gdb_bpt_instr = { 0x91, 0xd0, 0x20, 0x72 },
};