arch/tile: core support for Tilera 32-bit chips.

This change is the core kernel support for TILEPro and TILE64 chips.
No driver support (except the console driver) is included yet.

This includes the relevant Linux headers in asm/; the low-level
low-level "Tile architecture" headers in arch/, which are
shared with the hypervisor, etc., and are build-system agnostic;
and the relevant hypervisor headers in hv/.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Reviewed-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 193 insertions, 0 deletions

diff --git a/arch/tile/include/asm/backtrace.h b/arch/tile/include/asm/backtrace.h
new file mode 100644
index 000000000000..6970bfcad549
--- /dev/null
+++ b/arch/tile/include/asm/backtrace.h
@@ -0,0 +1,193 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#ifndef _TILE_BACKTRACE_H
+#define _TILE_BACKTRACE_H
+
+
+
+#include <linux/types.h>
+
+#include <arch/chip.h>
+
+#if 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'.
+ * Returns true if successful, else false (e.g. memory not readable).
+ */
+typedef bool (*BacktraceMemoryReader)(void *result,
+				      VirtualAddress address,
+				      unsigned int size,
+				      void *extra);
+
+typedef struct {
+	/** Current PC. */
+	VirtualAddress pc;
+
+	/** Current stack pointer value. */
+	VirtualAddress sp;
+
+	/** Current frame pointer value (i.e. caller's stack pointer) */
+	VirtualAddress fp;
+
+	/** Internal use only: caller's PC for first frame. */
+	VirtualAddress initial_frame_caller_pc;
+
+	/** Internal use only: callback to read memory. */
+	BacktraceMemoryReader 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. */
+	PC_LOC_UNKNOWN,
+
+	/* The caller's pc is currently in lr. */
+	PC_LOC_IN_LR,
+
+	/* The caller's pc can be found by dereferencing the caller's sp. */
+	PC_LOC_ON_STACK
+
+} CallerPCLocation;
+
+
+typedef enum {
+
+	/* We have no idea what the caller's sp is. */
+	SP_LOC_UNKNOWN,
+
+	/* The caller's sp is currently in r52. */
+	SP_LOC_IN_R52,
+
+	/* The caller's sp can be found by adding a certain constant
+	 * to the current value of sp.
+	 */
+	SP_LOC_OFFSET
+
+} CallerSPLocation;
+
+
+/* Bit values ORed into CALLER_* values for info ops. */
+enum {
+	/* Setting the low bit on any of these values means the info op
+	 * applies only to one bundle ago.
+	 */
+	ONE_BUNDLE_AGO_FLAG = 1,
+
+	/* Setting this bit on a CALLER_SP_* value means the PC is in LR.
+	 * If not set, PC is on the stack.
+	 */
+	PC_IN_LR_FLAG = 2,
+
+	/* This many of the low bits of a CALLER_SP_* value are for the
+	 * flag bits above.
+	 */
+	NUM_INFO_OP_FLAGS = 2,
+
+	/* We cannot have one in the memory pipe so this is the maximum. */
+	MAX_INFO_OPS_PER_BUNDLE = 2
+};
+
+
+/** Internal constants used to define 'info' operands. */
+enum {
+	/* 0 and 1 are reserved, as are all negative numbers. */
+
+	CALLER_UNKNOWN_BASE = 2,
+
+	CALLER_SP_IN_R52_BASE = 4,
+
+	CALLER_SP_OFFSET_BASE = 8
+};
+
+
+/** Current backtracer state describing where it thinks the caller is. */
+typedef struct {
+	/*
+	 * Public fields
+	 */
+
+	/* How do we find the caller's PC? */
+	CallerPCLocation pc_location : 8;
+
+	/* How do we find the caller's SP? */
+	CallerSPLocation sp_location : 8;
+
+	/* If sp_location == SP_LOC_OFFSET, then caller_sp == sp +
+	 * loc->sp_offset. Else this field is undefined.
+	 */
+	uint16_t sp_offset;
+
+	/* In the most recently visited bundle a terminating bundle? */
+	bool at_terminating_bundle;
+
+	/*
+	 * Private fields
+	 */
+
+	/* Will the forward scanner see someone clobbering sp
+	 * (i.e. changing it with something other than addi sp, sp, N?)
+	 */
+	bool sp_clobber_follows;
+
+	/* Operand to next "visible" info op (no more than one bundle past
+	 * the next terminating bundle), or -32768 if none.
+	 */
+	int16_t next_info_operand;
+
+	/* Is the info of in next_info_op in the very next bundle? */
+	bool is_next_info_operand_adjacent;
+
+} CallerLocation;
+
+
+
+
+#endif /* _TILE_BACKTRACE_H */