arch/tile: refactor backtracing code

This change is the result of some work to make the backtrace code more
shareable between kernel, libc, and gdb.

For the kernel, some good effects are to eliminate the hacky
"VirtualAddress" typedef in favor of "unsigned long", to eliminate a
bunch of spurious kernel doc comments, to remove the dead "bt_read_memory"
function, and to use "__tilegx__" in #ifdefs instead of "TILE_CHIP".

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

3 files changed, 37 insertions, 59 deletions

diff --git a/arch/tile/include/asm/backtrace.h b/arch/tile/include/asm/backtrace.h
index f18887d82399..bd5399a69edf 100644
--- a/arch/tile/include/asm/backtrace.h
+++ b/arch/tile/include/asm/backtrace.h
@@ -12,80 +12,41 @@
  *   more details.
  */
 
-#ifndef _TILE_BACKTRACE_H
-#define _TILE_BACKTRACE_H
-
-
+#ifndef _ASM_TILE_BACKTRACE_H
+#define _ASM_TILE_BACKTRACE_H
 
 #include <linux/types.h>
 
-#include <arch/chip.h>
-
-#if defined(__tile__)
-typedef unsigned long VirtualAddress;
-#elif CHIP_VA_WIDTH() > 32
-typedef unsigned long long VirtualAddress;
-#else
-typedef unsigned int VirtualAddress;
-#endif
-
-
-/** Reads 'size' bytes from 'address' and writes the data to 'result'.
+/* Reads 'size' bytes from 'address' and writes the data to 'result'.
  * Returns true if successful, else false (e.g. memory not readable).
  */
 typedef bool (*BacktraceMemoryReader)(void *result,
-				      VirtualAddress address,
+				      unsigned long address,
 				      unsigned int size,
 				      void *extra);
 
 typedef struct {
-	/** Current PC. */
-	VirtualAddress pc;
+	/* Current PC. */
+	unsigned long pc;
 
-	/** Current stack pointer value. */
-	VirtualAddress sp;
+	/* Current stack pointer value. */
+	unsigned long sp;
 
-	/** Current frame pointer value (i.e. caller's stack pointer) */
-	VirtualAddress fp;
+	/* Current frame pointer value (i.e. caller's stack pointer) */
+	unsigned long fp;
 
-	/** Internal use only: caller's PC for first frame. */
-	VirtualAddress initial_frame_caller_pc;
+	/* Internal use only: caller's PC for first frame. */
+	unsigned long initial_frame_caller_pc;
 
-	/** Internal use only: callback to read memory. */
+	/* Internal use only: callback to read memory. */
 	BacktraceMemoryReader read_memory_func;
 
-	/** Internal use only: arbitrary argument to read_memory_func. */
+	/* Internal use only: arbitrary argument to read_memory_func. */
 	void *read_memory_func_extra;
 
 } BacktraceIterator;
 
 
-/** Initializes a backtracer to start from the given location.
- *
- * If the frame pointer cannot be determined it is set to -1.
- *
- * @param state The state to be filled in.
- * @param read_memory_func A callback that reads memory. If NULL, a default
- *        value is provided.
- * @param read_memory_func_extra An arbitrary argument to read_memory_func.
- * @param pc The current PC.
- * @param lr The current value of the 'lr' register.
- * @param sp The current value of the 'sp' register.
- * @param r52 The current value of the 'r52' register.
- */
-extern void backtrace_init(BacktraceIterator *state,
-			   BacktraceMemoryReader read_memory_func,
-			   void *read_memory_func_extra,
-			   VirtualAddress pc, VirtualAddress lr,
-			   VirtualAddress sp, VirtualAddress r52);
-
-
-/** Advances the backtracing state to the calling frame, returning
- * true iff successful.
- */
-extern bool backtrace_next(BacktraceIterator *state);
-
-
 typedef enum {
 
 	/* We have no idea what the caller's pc is. */
@@ -138,7 +99,7 @@ enum {
 };
 
 
-/** Internal constants used to define 'info' operands. */
+/* Internal constants used to define 'info' operands. */
 enum {
 	/* 0 and 1 are reserved, as are all negative numbers. */
 
@@ -147,13 +108,10 @@ enum {
 	CALLER_SP_IN_R52_BASE = 4,
 
 	CALLER_SP_OFFSET_BASE = 8,
-
-	/* Marks the entry point of certain functions. */
-	ENTRY_POINT_INFO_OP = 16
 };
 
 
-/** Current backtracer state describing where it thinks the caller is. */
+/* Current backtracer state describing where it thinks the caller is. */
 typedef struct {
 	/*
 	 * Public fields
@@ -192,7 +150,13 @@ typedef struct {
 
 } CallerLocation;
 
+extern void backtrace_init(BacktraceIterator *state,
+                          BacktraceMemoryReader read_memory_func,
+                          void *read_memory_func_extra,
+                          unsigned long pc, unsigned long lr,
+                          unsigned long sp, unsigned long r52);
 
 
+extern bool backtrace_next(BacktraceIterator *state);
 
-#endif /* _TILE_BACKTRACE_H */
+#endif /* _ASM_TILE_BACKTRACE_H */
diff --git a/arch/tile/include/asm/opcode-tile_32.h b/arch/tile/include/asm/opcode-tile_32.h
index eda60ecbae3d..03df7b1e77bf 100644
--- a/arch/tile/include/asm/opcode-tile_32.h
+++ b/arch/tile/include/asm/opcode-tile_32.h
@@ -1502,5 +1502,12 @@ extern int parse_insn_tile(tile_bundle_bits bits,
                            decoded[TILE_MAX_INSTRUCTIONS_PER_BUNDLE]);
 
 
+/* Given a set of bundle bits and a specific pipe, returns which
+ * instruction the bundle contains in that pipe.
+ */
+extern const struct tile_opcode *
+find_opcode(tile_bundle_bits bits, tile_pipeline pipe);
+
+
 
 #endif /* opcode_tile_h */
diff --git a/arch/tile/include/asm/opcode-tile_64.h b/arch/tile/include/asm/opcode-tile_64.h
index eda60ecbae3d..03df7b1e77bf 100644
--- a/arch/tile/include/asm/opcode-tile_64.h
+++ b/arch/tile/include/asm/opcode-tile_64.h
@@ -1502,5 +1502,12 @@ extern int parse_insn_tile(tile_bundle_bits bits,
                            decoded[TILE_MAX_INSTRUCTIONS_PER_BUNDLE]);
 
 
+/* Given a set of bundle bits and a specific pipe, returns which
+ * instruction the bundle contains in that pipe.
+ */
+extern const struct tile_opcode *
+find_opcode(tile_bundle_bits bits, tile_pipeline pipe);
+
+
 
 #endif /* opcode_tile_h */