// SPDX-License-Identifier: GPL-2.0-only
/*
* arch/hexagon/kernel/kgdb.c - Hexagon KGDB Support
*
* Copyright (c) 2011-2012, The Linux Foundation. All rights reserved.
*/
#include <linux/irq.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/kdebug.h>
#include <linux/kgdb.h>
/* All registers are 4 bytes, for now */
#define GDB_SIZEOF_REG 4
/* The register names are used during printing of the regs;
* Keep these at three letters to pretty-print. */
struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
{ " r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, r00)},
{ " r1", GDB_SIZEOF_REG, offsetof(struct pt_regs, r01)},
{ " r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, r02)},
{ " r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, r03)},
{ " r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, r04)},
{ " r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, r05)},
{ " r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, r06)},
{ " r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, r07)},
{ " r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, r08)},
{ " r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, r09)},
{ "r10", GDB_SIZEOF_REG, offsetof(struct pt_regs, r10)},
{ "r11", GDB_SIZEOF_REG, offsetof(struct pt_regs, r11)},
{ "r12", GDB_SIZEOF_REG, offsetof(struct pt_regs, r12)},
{ "r13", GDB_SIZEOF_REG, offsetof(struct pt_regs, r13)},
{ "r14", GDB_SIZEOF_REG, offsetof(struct pt_regs, r14)},
{ "r15", GDB_SIZEOF_REG, offsetof(struct pt_regs, r15)},
{ "r16", GDB_SIZEOF_REG, offsetof(struct pt_regs, r16)},
{ "r17", GDB_SIZEOF_REG, offsetof(struct pt_regs, r17)},
{ "r18", GDB_SIZEOF_REG, offsetof(struct pt_regs, r18)},
{ "r19", GDB_SIZEOF_REG, offsetof(struct pt_regs, r19)},
{ "r20", GDB_SIZEOF_REG, offsetof(struct pt_regs, r20)},
{ "r21", GDB_SIZEOF_REG, offsetof(struct pt_regs, r21)},
{ "r22", GDB_SIZEOF_REG, offsetof(struct pt_regs, r22)},
{ "r23", GDB_SIZEOF_REG, offsetof(struct pt_regs, r23)},
{ "r24", GDB_SIZEOF_REG, offsetof(struct pt_regs, r24)},
{ "r25", GDB_SIZEOF_REG, offsetof(struct pt_regs, r25)},
{ "r26", GDB_SIZEOF_REG, offsetof(struct pt_regs, r26)},
{ "r27", GDB_SIZEOF_REG, offsetof(struct pt_regs, r27)},
{ "r28", GDB_SIZEOF_REG, offsetof(struct pt_regs, r28)},
{ "r29", GDB_SIZEOF_REG, offsetof(struct pt_regs, r29)},
{ "r30", GDB_SIZEOF_REG, offsetof(struct pt_regs, r30)},
{ "r31", GDB_SIZEOF_REG, offsetof(struct pt_regs, r31)},
{ "usr", GDB_SIZEOF_REG, offsetof(struct pt_regs, usr)},
{ "preds", GDB_SIZEOF_REG, offsetof(struct pt_regs, preds)},
{ " m0", GDB_SIZEOF_REG, offsetof(struct pt_regs, m0)},
{ " m1", GDB_SIZEOF_REG, offsetof(struct pt_regs, m1)},
{ "sa0", GDB_SIZEOF_REG, offsetof(struct pt_regs, sa0)},
{ "sa1", GDB_SIZEOF_REG, offsetof(struct pt_regs, sa1)},
{ "lc0", GDB_SIZEOF_REG, offsetof(struct pt_regs, lc0)},
{ "lc1", GDB_SIZEOF_REG, offsetof(struct pt_regs, lc1)},
{ " gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, gp)},
{ "ugp", GDB_SIZEOF_REG, offsetof(struct pt_regs, ugp)},
{ "cs0", GDB_SIZEOF_REG, offsetof(struct pt_regs, cs0)},
{ "cs1", GDB_SIZEOF_REG, offsetof(struct pt_regs, cs1)},
{ "psp", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmpsp)},
{ "elr", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmel)},
{ "est", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmest)},
{ "badva", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmbadva)},
{ "restart_r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, restart_r0)},
{ "syscall_nr", GDB_SIZEOF_REG, offsetof(struct pt_regs, syscall_nr)},
};
const struct kgdb_arch arch_kgdb_ops = {
/* trap0(#0xDB) 0x0cdb0054 */
.gdb_bpt_instr = {0x54, 0x00, 0xdb, 0x0c},
};
char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
{
if (regno >= DBG_MAX_REG_NUM || regno < 0)
return NULL;
*((unsigned long *) mem) = *((unsigned long *) ((void *)regs +
dbg_reg_def[regno].offset));
return dbg_reg_def[regno].name;
}
int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
{
if (regno >= DBG_MAX_REG_NUM || regno < 0)
return -EINVAL;
*((unsigned long *) ((void *)regs + dbg_reg_def[regno].offset)) =
*((unsigned long *) mem);
return 0;
}
void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
{
instruction_pointer(regs) = pc;
}
/* Not yet working */
void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs,
struct task_struct *task)
{
struct pt_regs *thread_regs;
if (task == NULL)
return;
/* Initialize to zero */
memset(gdb_regs, 0, NUMREGBYTES);
/* Otherwise, we have only some registers from switch_to() */
thread_regs = task_pt_regs(task);
gdb_regs[0] = thread_regs->r00;
}
/**
* kgdb_arch_handle_exception - Handle architecture specific GDB packets.
* @vector: The error vector of the exception that happened.
* @signo: The signal number of the exception that happened.
* @err_code: The error code of the exception that happened.
* @remcom_in_buffer: The buffer of the packet we have read.
* @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
* @regs: The &struct pt_regs of the current process.
*
* This function MUST handle the 'c' and 's' command packets,
* as well packets to set / remove a hardware breakpoint, if used.
* If there are additional packets which the hardware needs to handle,
* they are handled here. The code should return -1 if it wants to
* process more packets, and a %0 or %1 if it wants to exit from the
* kgdb callback.
*
* Not yet working.
*/
int kgdb_arch_handle_exception(int vector, int signo, int err_code,
char *remcom_in_buffer, char *remcom_out_buffer,
struct pt_regs *linux_regs)
{
switch (remcom_in_buffer[0]) {
case 's':
case 'c':
return 0;
}
/* Stay in the debugger. */
return -1;
}
static int __kgdb_notify(struct die_args *args, unsigned long cmd)
{
/* cpu roundup */
if (atomic_read(&kgdb_active) != -1) {
kgdb_nmicallback(smp_processor_id(), args->regs);
return NOTIFY_STOP;
}
if (user_mode(args->regs))
return NOTIFY_DONE;
if (kgdb_handle_exception(args->trapnr & 0xff, args->signr, args->err,
args->regs))
return NOTIFY_DONE;
return NOTIFY_STOP;
}
static int
kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
{
unsigned long flags;
int ret;
local_irq_save(flags);
ret = __kgdb_notify(ptr, cmd);
local_irq_restore(flags);
return ret;
}
static struct notifier_block kgdb_notifier = {
.notifier_call = kgdb_notify,
/*
* Lowest-prio notifier priority, we want to be notified last:
*/
.priority = -INT_MAX,
};
/**
* kgdb_arch_init - Perform any architecture specific initialization.
*
* This function will handle the initialization of any architecture
* specific callbacks.
*/
int kgdb_arch_init(void)
{
return register_die_notifier(&kgdb_notifier);
}
/**
* kgdb_arch_exit - Perform any architecture specific uninitalization.
*
* This function will handle the uninitalization of any architecture
* specific callbacks, for dynamic registration and unregistration.
*/
void kgdb_arch_exit(void)
{
unregister_die_notifier(&kgdb_notifier);
}