Initial import

1 files changed, 409 insertions, 0 deletions

diff --git a/arch/mips/kernel/kgdb.c b/arch/mips/kernel/kgdb.c
new file mode 100644
index 000000000..7afcc2f22
--- /dev/null
+++ b/arch/mips/kernel/kgdb.c
@@ -0,0 +1,409 @@
+/*
+ *  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);
+}