sh: generic BUG() support.

Wire up GENERIC_BUG for SH. This moves off of the special bug
frame and on to the generic struct bug_entry. Roughly the same
semantics are retained, and we can kill off some of the verbose
BUG() reporting code.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 61 insertions, 31 deletions

diff --git a/include/asm-sh/bug.h b/include/asm-sh/bug.h
index 2f89dd06d0cd..794c36daf06d 100644
--- a/include/asm-sh/bug.h
+++ b/include/asm-sh/bug.h
@@ -2,50 +2,80 @@
 #define __ASM_SH_BUG_H
 
 #ifdef CONFIG_BUG
-
-struct bug_frame {
-        unsigned short  opcode;
-        unsigned short  line;
-        const char      *file;
-        const char      *func;
-};
-
-struct pt_regs;
-
-extern void handle_BUG(struct pt_regs *);
+#define HAVE_ARCH_BUG
+#define HAVE_ARCH_WARN_ON
 
 #define TRAPA_BUG_OPCODE        0xc33e  /* trapa #0x3e */
 
+/**
+ * _EMIT_BUG_ENTRY
+ * %1 - __FILE__
+ * %2 - __LINE__
+ * %3 - trap type
+ * %4 - sizeof(struct bug_entry)
+ *
+ * The trapa opcode itself sits in %0.
+ * The %O notation is used to avoid # generation.
+ *
+ * The offending file and line are encoded in the __bug_table section.
+ */
 #ifdef CONFIG_DEBUG_BUGVERBOSE
+#define _EMIT_BUG_ENTRY                         \
+        "\t.pushsection __bug_table,\"a\"\n"    \
+        "2:\t.long 1b, %O1\n"                   \
+        "\t.short %O2, %O3\n"                   \
+        "\t.org 2b+%O4\n"                       \
+        "\t.popsection\n"
+#else
+#define _EMIT_BUG_ENTRY                         \
+        "\t.pushsection __bug_table,\"a\"\n"    \
+        "2:\t.long 1b\n"                        \
+        "\t.short %O3\n"                        \
+        "\t.org 2b+%O4\n"                       \
+        "\t.popsection\n"
+#endif
 
 #define BUG()                                           \
 do {                                                    \
         __asm__ __volatile__ (                          \
-                ".align 2\n\t"                          \
-                ".short %O0\n\t"                        \
-                ".short %O1\n\t"                        \
-                ".long  %O2\n\t"                        \
-                ".long  %O3\n\t"                        \
-                :                                       \
-                : "n" (TRAPA_BUG_OPCODE),               \
-                  "i" (__LINE__), "X" (__FILE__),       \
-                  "X" (__FUNCTION__));                  \
+                "1:\t.short %O0\n"                      \
+                _EMIT_BUG_ENTRY                         \
+                 :                                      \
+                 : "n" (TRAPA_BUG_OPCODE),              \
+                   "i" (__FILE__),                      \
+                   "i" (__LINE__), "i" (0),             \
+                   "i" (sizeof(struct bug_entry)));     \
 } while (0)
 
-#else
-
-#define BUG()                                   \
-do {                                            \
-        __asm__ __volatile__ (                  \
-                ".align 2\n\t"                  \
-                ".short %O0\n\t"                \
-                :                               \
-                : "n" (TRAPA_BUG_OPCODE));      \
+#define __WARN()                                        \
+do {                                                    \
+        __asm__ __volatile__ (                          \
+                "1:\t.short %O0\n"                      \
+                 _EMIT_BUG_ENTRY                        \
+                 :                                      \
+                 : "n" (TRAPA_BUG_OPCODE),              \
+                   "i" (__FILE__),                      \
+                   "i" (__LINE__),                      \
+                   "i" (BUGFLAG_WARNING),               \
+                   "i" (sizeof(struct bug_entry)));     \
 } while (0)
 
-#endif /* CONFIG_DEBUG_BUGVERBOSE */
+#define WARN_ON(x) ({                                           \
+        typeof(x) __ret_warn_on = (x);                          \
+        if (__builtin_constant_p(__ret_warn_on)) {              \
+                if (__ret_warn_on)                              \
+                        __WARN();                               \
+        } else {                                                \
+                if (unlikely(__ret_warn_on))                    \
+                        __WARN();                               \
+        }                                                       \
+        unlikely(__ret_warn_on);                                \
+})
 
-#define HAVE_ARCH_BUG
+struct pt_regs;
+
+/* arch/sh/kernel/traps.c */
+void handle_BUG(struct pt_regs *);
 
 #endif /* CONFIG_BUG */