[AVR32] Clean up exception handling code

  * Use generic BUG() handling
  * Remove some useless debug statements
  * Use a common function _exception() to send signals or oops when
    an exception can't be handled. This makes sure init doesn't
    enter an infinite exception loop as well. Borrowed from powerpc.
  * Add some basic exception tracing support to the page fault code.
  * Rework dump_stack(), show_regs() and friends and move everything
    into process.c
  * Print information about configuration options and chip type when
    oopsing

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>

3 files changed, 45 insertions, 24 deletions

diff --git a/include/asm-avr32/bug.h b/include/asm-avr32/bug.h
index 521766bc9366..afdcd79a2966 100644
--- a/include/asm-avr32/bug.h
+++ b/include/asm-avr32/bug.h
@@ -18,27 +18,53 @@
 
 #ifdef CONFIG_DEBUG_BUGVERBOSE
 
-#define BUG()                                                           \
-        do {                                                            \
-                asm volatile(".hword    %0\n\t"                         \
-                             ".hword    %1\n\t"                         \
-                             ".long     %2"                             \
-                             :                                          \
-                             : "n"(AVR32_BUG_OPCODE),                   \
-                               "i"(__LINE__), "X"(__FILE__));           \
-        } while (0)
+#define _BUG_OR_WARN(flags)                                             \
+        asm volatile(                                                   \
+                "1:     .hword  %0\n"                                   \
+                "       .section __bug_table,\"a\",@progbits\n"         \
+                "2:     .long   1b\n"                                   \
+                "       .long   %1\n"                                   \
+                "       .short  %2\n"                                   \
+                "       .short  %3\n"                                   \
+                "       .org    2b + %4\n"                              \
+                "       .previous"                                      \
+                :                                                       \
+                : "i"(AVR32_BUG_OPCODE), "i"(__FILE__),                 \
+                  "i"(__LINE__), "i"(flags),                            \
+                  "i"(sizeof(struct bug_entry)))
 
 #else
 
+#define _BUG_OR_WARN(flags)                                             \
+        asm volatile(                                                   \
+                "1:     .hword  %0\n"                                   \
+                "       .section __bug_table,\"a\",@progbits\n"         \
+                "2:     .long   1b\n"                                   \
+                "       .short  %1\n"                                   \
+                "       .org    2b + %2\n"                              \
+                "       .previous"                                      \
+                :                                                       \
+                : "i"(AVR32_BUG_OPCODE), "i"(flags),                    \
+                  "i"(sizeof(struct bug_entry)))
+
+#endif /* CONFIG_DEBUG_BUGVERBOSE */
+
 #define BUG()                                                           \
         do {                                                            \
-                asm volatile(".hword    %0\n\t"                         \
-                             : : "n"(AVR32_BUG_OPCODE));                \
+                _BUG_OR_WARN(0);                                        \
+                for (;;);                                               \
         } while (0)
 
-#endif /* CONFIG_DEBUG_BUGVERBOSE */
+#define WARN_ON(condition)                                                      \
+        ({                                                              \
+                typeof(condition) __ret_warn_on = (condition);          \
+                if (unlikely(__ret_warn_on))                            \
+                        _BUG_OR_WARN(BUGFLAG_WARNING);                  \
+                unlikely(__ret_warn_on);                                \
+        })
 
 #define HAVE_ARCH_BUG
+#define HAVE_ARCH_WARN_ON
 
 #endif /* CONFIG_BUG */
 
diff --git a/include/asm-avr32/processor.h b/include/asm-avr32/processor.h
index cbb89ccd3f05..6a64833756a6 100644
--- a/include/asm-avr32/processor.h
+++ b/include/asm-avr32/processor.h
@@ -134,10 +134,10 @@ extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
 #define thread_saved_pc(tsk)    ((tsk)->thread.cpu_context.pc)
 
 struct pt_regs;
-void show_trace(struct task_struct *task, unsigned long *stack,
-                struct pt_regs *regs);
-
 extern unsigned long get_wchan(struct task_struct *p);
+extern void show_regs_log_lvl(struct pt_regs *regs, const char *log_lvl);
+extern void show_stack_log_lvl(struct task_struct *tsk, unsigned long sp,
+                               struct pt_regs *regs, const char *log_lvl);
 
 #define KSTK_EIP(tsk)   ((tsk)->thread.cpu_context.pc)
 #define KSTK_ESP(tsk)   ((tsk)->thread.cpu_context.ksp)
diff --git a/include/asm-avr32/system.h b/include/asm-avr32/system.h
index ac596058697d..a8236bacc878 100644
--- a/include/asm-avr32/system.h
+++ b/include/asm-avr32/system.h
@@ -9,6 +9,7 @@
 #define __ASM_AVR32_SYSTEM_H
 
 #include <linux/compiler.h>
+#include <linux/linkage.h>
 #include <linux/types.h>
 
 #include <asm/ptrace.h>
@@ -140,15 +141,9 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
                                    sizeof(*(ptr))))
 
 struct pt_regs;
-extern void __die(const char *, struct pt_regs *, unsigned long,
-                  const char *, const char *, unsigned long);
-extern void __die_if_kernel(const char *, struct pt_regs *, unsigned long,
-                            const char *, const char *, unsigned long);
-
-#define die(msg, regs, err)                                     \
-        __die(msg, regs, err, __FILE__ ":", __FUNCTION__, __LINE__)
-#define die_if_kernel(msg, regs, err)                                   \
-        __die_if_kernel(msg, regs, err, __FILE__ ":", __FUNCTION__, __LINE__)
+void NORET_TYPE die(const char *str, struct pt_regs *regs, long err);
+void _exception(long signr, struct pt_regs *regs, int code,
+                unsigned long addr);
 
 #define arch_align_stack(x)     (x)