linux/arch/mips/kernel/kgdb.c
Leonid Yegoshin 6ebda44f36 MIPS: kernel: {ftrace,kgdb}: Set correct address limit for cache flushes
When flushing the icache, make sure the address limit is correct
so the appropriate 'cache' instruction will be used. This has no
impact on cores operating in non-eva mode. However, when EVA is
enabled, we ensure that 'cache' will be used instead of 'cachee'.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
2014-03-26 23:09:18 +01:00

410 lines
11 KiB
C

/*
* Originally written by Glenn Engel, Lake Stevens Instrument Division
*
* Contributed by HP Systems
*
* Modified for Linux/MIPS (and MIPS in general) by Andreas Busse
* Send complaints, suggestions etc. to <andy@waldorf-gmbh.de>
*
* Copyright (C) 1995 Andreas Busse
*
* Copyright (C) 2003 MontaVista Software Inc.
* Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
*
* Copyright (C) 2004-2005 MontaVista Software Inc.
* Author: Manish Lachwani, mlachwani@mvista.com or manish@koffee-break.com
*
* Copyright (C) 2007-2008 Wind River Systems, Inc.
* Author/Maintainer: Jason Wessel, jason.wessel@windriver.com
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
#include <linux/ptrace.h> /* for linux pt_regs struct */
#include <linux/kgdb.h>
#include <linux/kdebug.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <asm/inst.h>
#include <asm/fpu.h>
#include <asm/cacheflush.h>
#include <asm/processor.h>
#include <asm/sigcontext.h>
#include <asm/uaccess.h>
static struct hard_trap_info {
unsigned char tt; /* Trap type code for MIPS R3xxx and R4xxx */
unsigned char signo; /* Signal that we map this trap into */
} hard_trap_info[] = {
{ 6, SIGBUS }, /* instruction bus error */
{ 7, SIGBUS }, /* data bus error */
{ 9, SIGTRAP }, /* break */
/* { 11, SIGILL }, */ /* CPU unusable */
{ 12, SIGFPE }, /* overflow */
{ 13, SIGTRAP }, /* trap */
{ 14, SIGSEGV }, /* virtual instruction cache coherency */
{ 15, SIGFPE }, /* floating point exception */
{ 23, SIGSEGV }, /* watch */
{ 31, SIGSEGV }, /* virtual data cache coherency */
{ 0, 0} /* Must be last */
};
struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
{
{ "zero", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[0]) },
{ "at", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[1]) },
{ "v0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[2]) },
{ "v1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[3]) },
{ "a0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[4]) },
{ "a1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[5]) },
{ "a2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[6]) },
{ "a3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[7]) },
{ "t0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[8]) },
{ "t1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[9]) },
{ "t2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[10]) },
{ "t3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[11]) },
{ "t4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[12]) },
{ "t5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[13]) },
{ "t6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[14]) },
{ "t7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[15]) },
{ "s0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[16]) },
{ "s1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[17]) },
{ "s2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[18]) },
{ "s3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[19]) },
{ "s4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[20]) },
{ "s5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[21]) },
{ "s6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[22]) },
{ "s7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[23]) },
{ "t8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[24]) },
{ "t9", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[25]) },
{ "k0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[26]) },
{ "k1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[27]) },
{ "gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[28]) },
{ "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[29]) },
{ "s8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[30]) },
{ "ra", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[31]) },
{ "sr", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_status) },
{ "lo", GDB_SIZEOF_REG, offsetof(struct pt_regs, lo) },
{ "hi", GDB_SIZEOF_REG, offsetof(struct pt_regs, hi) },
{ "bad", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_badvaddr) },
{ "cause", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_cause) },
{ "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_epc) },
{ "f0", GDB_SIZEOF_REG, 0 },
{ "f1", GDB_SIZEOF_REG, 1 },
{ "f2", GDB_SIZEOF_REG, 2 },
{ "f3", GDB_SIZEOF_REG, 3 },
{ "f4", GDB_SIZEOF_REG, 4 },
{ "f5", GDB_SIZEOF_REG, 5 },
{ "f6", GDB_SIZEOF_REG, 6 },
{ "f7", GDB_SIZEOF_REG, 7 },
{ "f8", GDB_SIZEOF_REG, 8 },
{ "f9", GDB_SIZEOF_REG, 9 },
{ "f10", GDB_SIZEOF_REG, 10 },
{ "f11", GDB_SIZEOF_REG, 11 },
{ "f12", GDB_SIZEOF_REG, 12 },
{ "f13", GDB_SIZEOF_REG, 13 },
{ "f14", GDB_SIZEOF_REG, 14 },
{ "f15", GDB_SIZEOF_REG, 15 },
{ "f16", GDB_SIZEOF_REG, 16 },
{ "f17", GDB_SIZEOF_REG, 17 },
{ "f18", GDB_SIZEOF_REG, 18 },
{ "f19", GDB_SIZEOF_REG, 19 },
{ "f20", GDB_SIZEOF_REG, 20 },
{ "f21", GDB_SIZEOF_REG, 21 },
{ "f22", GDB_SIZEOF_REG, 22 },
{ "f23", GDB_SIZEOF_REG, 23 },
{ "f24", GDB_SIZEOF_REG, 24 },
{ "f25", GDB_SIZEOF_REG, 25 },
{ "f26", GDB_SIZEOF_REG, 26 },
{ "f27", GDB_SIZEOF_REG, 27 },
{ "f28", GDB_SIZEOF_REG, 28 },
{ "f29", GDB_SIZEOF_REG, 29 },
{ "f30", GDB_SIZEOF_REG, 30 },
{ "f31", GDB_SIZEOF_REG, 31 },
{ "fsr", GDB_SIZEOF_REG, 0 },
{ "fir", GDB_SIZEOF_REG, 0 },
};
int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
{
int fp_reg;
if (regno < 0 || regno >= DBG_MAX_REG_NUM)
return -EINVAL;
if (dbg_reg_def[regno].offset != -1 && regno < 38) {
memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
dbg_reg_def[regno].size);
} else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) {
/* FP registers 38 -> 69 */
if (!(regs->cp0_status & ST0_CU1))
return 0;
if (regno == 70) {
/* Process the fcr31/fsr (register 70) */
memcpy((void *)&current->thread.fpu.fcr31, mem,
dbg_reg_def[regno].size);
goto out_save;
} else if (regno == 71) {
/* Ignore the fir (register 71) */
goto out_save;
}
fp_reg = dbg_reg_def[regno].offset;
memcpy((void *)&current->thread.fpu.fpr[fp_reg], mem,
dbg_reg_def[regno].size);
out_save:
restore_fp(current);
}
return 0;
}
char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
{
int fp_reg;
if (regno >= DBG_MAX_REG_NUM || regno < 0)
return NULL;
if (dbg_reg_def[regno].offset != -1 && regno < 38) {
/* First 38 registers */
memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
dbg_reg_def[regno].size);
} else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) {
/* FP registers 38 -> 69 */
if (!(regs->cp0_status & ST0_CU1))
goto out;
save_fp(current);
if (regno == 70) {
/* Process the fcr31/fsr (register 70) */
memcpy(mem, (void *)&current->thread.fpu.fcr31,
dbg_reg_def[regno].size);
goto out;
} else if (regno == 71) {
/* Ignore the fir (register 71) */
memset(mem, 0, dbg_reg_def[regno].size);
goto out;
}
fp_reg = dbg_reg_def[regno].offset;
memcpy(mem, (void *)&current->thread.fpu.fpr[fp_reg],
dbg_reg_def[regno].size);
}
out:
return dbg_reg_def[regno].name;
}
void arch_kgdb_breakpoint(void)
{
__asm__ __volatile__(
".globl breakinst\n\t"
".set\tnoreorder\n\t"
"nop\n"
"breakinst:\tbreak\n\t"
"nop\n\t"
".set\treorder");
}
static void kgdb_call_nmi_hook(void *ignored)
{
mm_segment_t old_fs;
old_fs = get_fs();
set_fs(get_ds());
kgdb_nmicallback(raw_smp_processor_id(), NULL);
set_fs(old_fs);
}
void kgdb_roundup_cpus(unsigned long flags)
{
local_irq_enable();
smp_call_function(kgdb_call_nmi_hook, NULL, 0);
local_irq_disable();
}
static int compute_signal(int tt)
{
struct hard_trap_info *ht;
for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
if (ht->tt == tt)
return ht->signo;
return SIGHUP; /* default for things we don't know about */
}
/*
* Similar to regs_to_gdb_regs() except that process is sleeping and so
* we may not be able to get all the info.
*/
void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
{
int reg;
struct thread_info *ti = task_thread_info(p);
unsigned long ksp = (unsigned long)ti + THREAD_SIZE - 32;
struct pt_regs *regs = (struct pt_regs *)ksp - 1;
#if (KGDB_GDB_REG_SIZE == 32)
u32 *ptr = (u32 *)gdb_regs;
#else
u64 *ptr = (u64 *)gdb_regs;
#endif
for (reg = 0; reg < 16; reg++)
*(ptr++) = regs->regs[reg];
/* S0 - S7 */
for (reg = 16; reg < 24; reg++)
*(ptr++) = regs->regs[reg];
for (reg = 24; reg < 28; reg++)
*(ptr++) = 0;
/* GP, SP, FP, RA */
for (reg = 28; reg < 32; reg++)
*(ptr++) = regs->regs[reg];
*(ptr++) = regs->cp0_status;
*(ptr++) = regs->lo;
*(ptr++) = regs->hi;
*(ptr++) = regs->cp0_badvaddr;
*(ptr++) = regs->cp0_cause;
*(ptr++) = regs->cp0_epc;
}
void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
{
regs->cp0_epc = pc;
}
/*
* Calls linux_debug_hook before the kernel dies. If KGDB is enabled,
* then try to fall into the debugger
*/
static int kgdb_mips_notify(struct notifier_block *self, unsigned long cmd,
void *ptr)
{
struct die_args *args = (struct die_args *)ptr;
struct pt_regs *regs = args->regs;
int trap = (regs->cp0_cause & 0x7c) >> 2;
mm_segment_t old_fs;
#ifdef CONFIG_KPROBES
/*
* Return immediately if the kprobes fault notifier has set
* DIE_PAGE_FAULT.
*/
if (cmd == DIE_PAGE_FAULT)
return NOTIFY_DONE;
#endif /* CONFIG_KPROBES */
/* Userspace events, ignore. */
if (user_mode(regs))
return NOTIFY_DONE;
/* Kernel mode. Set correct address limit */
old_fs = get_fs();
set_fs(get_ds());
if (atomic_read(&kgdb_active) != -1)
kgdb_nmicallback(smp_processor_id(), regs);
if (kgdb_handle_exception(trap, compute_signal(trap), cmd, regs)) {
set_fs(old_fs);
return NOTIFY_DONE;
}
if (atomic_read(&kgdb_setting_breakpoint))
if ((trap == 9) && (regs->cp0_epc == (unsigned long)breakinst))
regs->cp0_epc += 4;
/* In SMP mode, __flush_cache_all does IPI */
local_irq_enable();
__flush_cache_all();
set_fs(old_fs);
return NOTIFY_STOP;
}
#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
int kgdb_ll_trap(int cmd, const char *str,
struct pt_regs *regs, long err, int trap, int sig)
{
struct die_args args = {
.regs = regs,
.str = str,
.err = err,
.trapnr = trap,
.signr = sig,
};
if (!kgdb_io_module_registered)
return NOTIFY_DONE;
return kgdb_mips_notify(NULL, cmd, &args);
}
#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
static struct notifier_block kgdb_notifier = {
.notifier_call = kgdb_mips_notify,
};
/*
* Handle the 'c' command
*/
int kgdb_arch_handle_exception(int vector, int signo, int err_code,
char *remcom_in_buffer, char *remcom_out_buffer,
struct pt_regs *regs)
{
char *ptr;
unsigned long address;
switch (remcom_in_buffer[0]) {
case 'c':
/* handle the optional parameter */
ptr = &remcom_in_buffer[1];
if (kgdb_hex2long(&ptr, &address))
regs->cp0_epc = address;
return 0;
}
return -1;
}
struct kgdb_arch arch_kgdb_ops;
/*
* We use kgdb_early_setup so that functions we need to call now don't
* cause trouble when called again later.
*/
int kgdb_arch_init(void)
{
union mips_instruction insn = {
.r_format = {
.opcode = spec_op,
.func = break_op,
}
};
memcpy(arch_kgdb_ops.gdb_bpt_instr, insn.byte, BREAK_INSTR_SIZE);
register_die_notifier(&kgdb_notifier);
return 0;
}
/*
* 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);
}