Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-mn10300

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-mn10300:
  MN10300: gcc 4.6 vs am33 inline assembly
  MN10300: Deprecate gdbstub
  MN10300: Allow KGDB to use the MN10300 serial ports
  MN10300: Emulate single stepping in KGDB on MN10300
  MN10300: Generalise kernel debugger kernel halt, reboot or power off hook
  KGDB: Notify GDB of machine halt, reboot or power off
  MN10300: Use KGDB
  MN10300: Create generic kernel debugger hooks
  MN10300: Create general kernel debugger cache flushing
  MN10300: Introduce a general config option for kernel debugger hooks
  MN10300: The icache invalidate functions should disable the icache first
  MN10300: gdbstub: Restrict single-stepping to non-preemptable non-SMP configs

Author: torvalds

arch/mn10300/Kconfig

@@ -3,6 +3,8 @@ config MN10300
 	select HAVE_OPROFILE
 	select HAVE_GENERIC_HARDIRQS
 	select GENERIC_HARDIRQS_NO_DEPRECATED
+	select HAVE_ARCH_TRACEHOOK
+	select HAVE_ARCH_KGDB
 
 config AM33_2
 	def_bool n
@@ -401,9 +403,9 @@ comment "[!] NOTE: A lower number/level indicates a higher priority (0 is highes
 comment "____Non-maskable interrupt levels____"
 comment "The following must be set to a higher priority than local_irq_disable() and on-chip serial"
 
-config GDBSTUB_IRQ_LEVEL
-	int "GDBSTUB interrupt priority"
-	depends on GDBSTUB
+config DEBUGGER_IRQ_LEVEL
+	int "DEBUGGER interrupt priority"
+	depends on KERNEL_DEBUGGER
 	range 0 1 if LINUX_CLI_LEVEL = 2
 	range 0 2 if LINUX_CLI_LEVEL = 3
 	range 0 3 if LINUX_CLI_LEVEL = 4
@@ -437,7 +439,7 @@ config LINUX_CLI_LEVEL
 	  EPSW.IM from 7.  Any interrupt is permitted for which the level is
 	  lower than EPSW.IM.
 
-	  Certain interrupts, such as GDBSTUB and virtual MN10300 on-chip
+	  Certain interrupts, such as DEBUGGER and virtual MN10300 on-chip
 	  serial DMA interrupts are allowed to interrupt normal disabled
 	  sections.
 

arch/mn10300/Kconfig.debug

@@ -36,7 +36,7 @@ config KPROBES
 
 config GDBSTUB
 	bool "Remote GDB kernel debugging"
-	depends on DEBUG_KERNEL
+	depends on DEBUG_KERNEL && DEPRECATED
 	select DEBUG_INFO
 	select FRAME_POINTER
 	help
@@ -46,6 +46,9 @@ config GDBSTUB
 	  RAM to avoid excessive linking time. This is only useful for kernel
 	  hackers. If unsure, say N.
 
+	  This is deprecated in favour of KGDB and will be removed in a later
+	  version.
+
 config GDBSTUB_IMMEDIATE
 	bool "Break into GDB stub immediately"
 	depends on GDBSTUB
@@ -54,6 +57,14 @@ config GDBSTUB_IMMEDIATE
 	  possible, leaving the program counter at the beginning of
 	  start_kernel() in init/main.c.
 
+config GDBSTUB_ALLOW_SINGLE_STEP
+	bool "Allow software single-stepping in GDB stub"
+	depends on GDBSTUB && !SMP && !PREEMPT
+	help
+	  Allow GDB stub to perform software single-stepping through the
+	  kernel.  This doesn't work very well on SMP or preemptible kernels as
+	  it uses temporary breakpoints to emulate single-stepping.
+
 config GDB_CONSOLE
 	bool "Console output to GDB"
 	depends on GDBSTUB
@@ -142,3 +153,7 @@ config GDBSTUB_ON_TTYSx
 	default y
 
 endmenu
+
+config KERNEL_DEBUGGER
+	def_bool y
+	depends on GDBSTUB || KGDB

arch/mn10300/include/asm/debugger.h

@@ -0,0 +1,43 @@
+/* Kernel debugger for MN10300
+ *
+ * Copyright (C) 2011 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells ([email protected])
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#ifndef _ASM_DEBUGGER_H
+#define _ASM_DEBUGGER_H
+
+#if defined(CONFIG_KERNEL_DEBUGGER)
+
+extern int debugger_intercept(enum exception_code, int, int, struct pt_regs *);
+extern int at_debugger_breakpoint(struct pt_regs *);
+
+#ifndef CONFIG_MN10300_DEBUGGER_CACHE_NO_FLUSH
+extern void debugger_local_cache_flushinv(void);
+extern void debugger_local_cache_flushinv_one(u8 *);
+#else
+static inline void debugger_local_cache_flushinv(void) {}
+static inline void debugger_local_cache_flushinv_one(u8 *addr) {}
+#endif
+
+#else /* CONFIG_KERNEL_DEBUGGER */
+
+static inline int debugger_intercept(enum exception_code excep,
+				     int signo, int si_code,
+				     struct pt_regs *regs)
+{
+	return 0;
+}
+
+static inline int at_debugger_breakpoint(struct pt_regs *regs)
+{
+	return 0;
+}
+
+#endif /* CONFIG_KERNEL_DEBUGGER */
+#endif /* _ASM_DEBUGGER_H */

arch/mn10300/include/asm/div64.h

@@ -15,6 +15,19 @@
 
 extern void ____unhandled_size_in_do_div___(void);
 
+/*
+ * Beginning with gcc 4.6, the MDR register is represented explicitly.  We
+ * must, therefore, at least explicitly clobber the register when we make
+ * changes to it.  The following assembly fragments *could* be rearranged in
+ * order to leave the moves to/from the MDR register to the compiler, but the
+ * gains would be minimal at best.
+ */
+#if __GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 6)
+# define CLOBBER_MDR_CC		"mdr", "cc"
+#else
+# define CLOBBER_MDR_CC		"cc"
+#endif
+
 /*
  * divide n by base, leaving the result in n and returning the remainder
  * - we can do this quite efficiently on the MN10300 by cascading the divides
@@ -29,7 +42,7 @@ extern void ____unhandled_size_in_do_div___(void);
 		    "mov	mdr,%1	\n"				\
 		    : "+r"(n), "=d"(__rem)				\
 		    : "r"(base), "1"(__rem)				\
-		    : "cc"						\
+		    : CLOBBER_MDR_CC					\
 		    );							\
 	} else if (sizeof(n) <= 8) {					\
 		union {							\
@@ -48,7 +61,7 @@ extern void ____unhandled_size_in_do_div___(void);
 		    : "=d"(__rem), "=r"(__quot.w[1]), "=r"(__quot.w[0])	\
 		    : "r"(base), "0"(__rem), "1"(__quot.w[1]),		\
 		      "2"(__quot.w[0])					\
-		    : "cc"						\
+		    : CLOBBER_MDR_CC					\
 		    );							\
 		n = __quot.l;						\
 	} else {							\
@@ -72,7 +85,7 @@ unsigned __muldiv64u(unsigned val, unsigned mult, unsigned div)
 					 * MDR = MDR:val%div */
 	    : "=r"(result)
 	    : "0"(val), "ir"(mult), "r"(div)
-	    : "cc"
+	    : CLOBBER_MDR_CC
 	    );
 
 	return result;
@@ -93,7 +106,7 @@ signed __muldiv64s(signed val, signed mult, signed div)
 					 * MDR = MDR:val%div */
 	    : "=r"(result)
 	    : "0"(val), "ir"(mult), "r"(div)
-	    : "cc"
+	    : CLOBBER_MDR_CC
 	    );
 
 	return result;

arch/mn10300/include/asm/fpu.h

@@ -55,7 +55,6 @@ static inline void clear_using_fpu(struct task_struct *tsk)
 
 extern asmlinkage void fpu_kill_state(struct task_struct *);
 extern asmlinkage void fpu_exception(struct pt_regs *, enum exception_code);
-extern asmlinkage void fpu_invalid_op(struct pt_regs *, enum exception_code);
 extern asmlinkage void fpu_init_state(void);
 extern asmlinkage void fpu_save(struct fpu_state_struct *);
 extern int fpu_setup_sigcontext(struct fpucontext *buf);
@@ -113,7 +112,6 @@ static inline void flush_fpu(void)
 
 extern asmlinkage
 void unexpected_fpu_exception(struct pt_regs *, enum exception_code);
-#define fpu_invalid_op unexpected_fpu_exception
 #define fpu_exception unexpected_fpu_exception
 
 struct task_struct;

arch/mn10300/include/asm/irqflags.h

@@ -20,7 +20,7 @@
 /*
  * interrupt control
  * - "disabled": run in IM1/2
- *   - level 0 - GDB stub
+ *   - level 0 - kernel debugger
  *   - level 1 - virtual serial DMA (if present)
  *   - level 5 - normal interrupt priority
  *   - level 6 - timer interrupt

arch/mn10300/include/asm/kgdb.h

@@ -0,0 +1,81 @@
+/* Kernel debugger for MN10300
+ *
+ * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells ([email protected])
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#ifndef _ASM_KGDB_H
+#define _ASM_KGDB_H
+
+/*
+ * BUFMAX defines the maximum number of characters in inbound/outbound
+ * buffers at least NUMREGBYTES*2 are needed for register packets
+ * Longer buffer is needed to list all threads
+ */
+#define BUFMAX			1024
+
+/*
+ * Note that this register image is in a different order than the register
+ * image that Linux produces at interrupt time.
+ */
+enum regnames {
+	GDB_FR_D0		= 0,
+	GDB_FR_D1		= 1,
+	GDB_FR_D2		= 2,
+	GDB_FR_D3		= 3,
+	GDB_FR_A0		= 4,
+	GDB_FR_A1		= 5,
+	GDB_FR_A2		= 6,
+	GDB_FR_A3		= 7,
+
+	GDB_FR_SP		= 8,
+	GDB_FR_PC		= 9,
+	GDB_FR_MDR		= 10,
+	GDB_FR_EPSW		= 11,
+	GDB_FR_LIR		= 12,
+	GDB_FR_LAR		= 13,
+	GDB_FR_MDRQ		= 14,
+
+	GDB_FR_E0		= 15,
+	GDB_FR_E1		= 16,
+	GDB_FR_E2		= 17,
+	GDB_FR_E3		= 18,
+	GDB_FR_E4		= 19,
+	GDB_FR_E5		= 20,
+	GDB_FR_E6		= 21,
+	GDB_FR_E7		= 22,
+
+	GDB_FR_SSP		= 23,
+	GDB_FR_MSP		= 24,
+	GDB_FR_USP		= 25,
+	GDB_FR_MCRH		= 26,
+	GDB_FR_MCRL		= 27,
+	GDB_FR_MCVF		= 28,
+
+	GDB_FR_FPCR		= 29,
+	GDB_FR_DUMMY0		= 30,
+	GDB_FR_DUMMY1		= 31,
+
+	GDB_FR_FS0		= 32,
+
+	GDB_FR_SIZE		= 64,
+};
+
+#define GDB_ORIG_D0		41
+#define NUMREGBYTES		(GDB_FR_SIZE*4)
+
+static inline void arch_kgdb_breakpoint(void)
+{
+	asm(".globl __arch_kgdb_breakpoint; __arch_kgdb_breakpoint: break");
+}
+extern u8 __arch_kgdb_breakpoint;
+
+#define BREAK_INSTR_SIZE	1
+#define CACHE_FLUSH_IS_SAFE	1
+
+#endif /* _ASM_KGDB_H */

arch/mn10300/include/asm/smp.h

@@ -34,7 +34,7 @@
 #define LOCAL_TIMER_IPI		193
 #define FLUSH_CACHE_IPI		194
 #define CALL_FUNCTION_NMI_IPI	195
-#define GDB_NMI_IPI		196
+#define DEBUGGER_NMI_IPI	196
 
 #define SMP_BOOT_IRQ		195
 
@@ -43,6 +43,7 @@
 #define LOCAL_TIMER_GxICR_LV	GxICR_LEVEL_4
 #define FLUSH_CACHE_GxICR_LV	GxICR_LEVEL_0
 #define SMP_BOOT_GxICR_LV	GxICR_LEVEL_0
+#define DEBUGGER_GxICR_LV	CONFIG_DEBUGGER_IRQ_LEVEL
 
 #define TIME_OUT_COUNT_BOOT_IPI	100
 #define DELAY_TIME_BOOT_IPI	75000
@@ -61,8 +62,9 @@
  * An alternate way of dealing with this could be to use the EPSW.S bits to
  * cache this information for systems with up to four CPUs.
  */
+#define arch_smp_processor_id()	(CPUID)
 #if 0
-#define raw_smp_processor_id()	(CPUID)
+#define raw_smp_processor_id()	(arch_smp_processor_id())
 #else
 #define raw_smp_processor_id()	(current_thread_info()->cpu)
 #endif

arch/mn10300/include/asm/thread_info.h

@@ -131,7 +131,11 @@ static inline unsigned long current_stack_pointer(void)
 		kmalloc_node(THREAD_SIZE, GFP_KERNEL, node)
 #endif
 
+#ifndef CONFIG_KGDB
 #define free_thread_info(ti)	kfree((ti))
+#else
+extern void free_thread_info(struct thread_info *);
+#endif
 #define get_thread_info(ti)	get_task_struct((ti)->task)
 #define put_thread_info(ti)	put_task_struct((ti)->task)
 

arch/mn10300/kernel/Makefile

@@ -21,11 +21,8 @@ obj-$(CONFIG_GDBSTUB) += gdb-stub.o gdb-low.o
 obj-$(CONFIG_GDBSTUB_ON_TTYSx) += gdb-io-serial.o gdb-io-serial-low.o
 obj-$(CONFIG_GDBSTUB_ON_TTYSMx) += gdb-io-ttysm.o gdb-io-ttysm-low.o
 
-ifeq ($(CONFIG_MN10300_CACHE_ENABLED),y)
-obj-$(CONFIG_GDBSTUB) += gdb-cache.o
-endif
-
 obj-$(CONFIG_MN10300_RTC) += rtc.o
 obj-$(CONFIG_PROFILE) += profile.o profile-low.o
 obj-$(CONFIG_MODULES) += module.o
 obj-$(CONFIG_KPROBES) += kprobes.o
+obj-$(CONFIG_KGDB) += kgdb.o