Merge tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic

Pul removal of obsolete architecture ports from Arnd Bergmann:
 "This removes the entire architecture code for blackfin, cris, frv,
  m32r, metag, mn10300, score, and tile, including the associated device
  drivers.

  I have been working with the (former) maintainers for each one to
  ensure that my interpretation was right and the code is definitely
  unused in mainline kernels. Many had fond memories of working on the
  respective ports to start with and getting them included in upstream,
  but also saw no point in keeping the port alive without any users.

  In the end, it seems that while the eight architectures are extremely
  different, they all suffered the same fate: There was one company in
  charge of an SoC line, a CPU microarchitecture and a software
  ecosystem, which was more costly than licensing newer off-the-shelf
  CPU cores from a third party (typically ARM, MIPS, or RISC-V). It
  seems that all the SoC product lines are still around, but have not
  used the custom CPU architectures for several years at this point. In
  contrast, CPU instruction sets that remain popular and have actively
  maintained kernel ports tend to all be used across multiple licensees.

  [ See the new nds32 port merged in the previous commit for the next
    generation of "one company in charge of an SoC line, a CPU
    microarchitecture and a software ecosystem"   - Linus ]

  The removal came out of a discussion that is now documented at
  https://lwn.net/Articles/748074/. Unlike the original plans, I'm not
  marking any ports as deprecated but remove them all at once after I
  made sure that they are all unused. Some architectures (notably tile,
  mn10300, and blackfin) are still being shipped in products with old
  kernels, but those products will never be updated to newer kernel
  releases.

  After this series, we still have a few architectures without mainline
  gcc support:

   - unicore32 and hexagon both have very outdated gcc releases, but the
     maintainers promised to work on providing something newer. At least
     in case of hexagon, this will only be llvm, not gcc.

   - openrisc, risc-v and nds32 are still in the process of finishing
     their support or getting it added to mainline gcc in the first
     place. They all have patched gcc-7.3 ports that work to some
     degree, but complete upstream support won't happen before gcc-8.1.
     Csky posted their first kernel patch set last week, their situation
     will be similar

  [ Palmer Dabbelt points out that RISC-V support is in mainline gcc
    since gcc-7, although gcc-7.3.0 is the recommended minimum  - Linus ]"

This really says it all:

 2498 files changed, 95 insertions(+), 467668 deletions(-)

* tag 'arch-removal' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (74 commits)
  MAINTAINERS: UNICORE32: Change email account
  staging: iio: remove iio-trig-bfin-timer driver
  tty: hvc: remove tile driver
  tty: remove bfin_jtag_comm and hvc_bfin_jtag drivers
  serial: remove tile uart driver
  serial: remove m32r_sio driver
  serial: remove blackfin drivers
  serial: remove cris/etrax uart drivers
  usb: Remove Blackfin references in USB support
  usb: isp1362: remove blackfin arch glue
  usb: musb: remove blackfin port
  usb: host: remove tilegx platform glue
  pwm: remove pwm-bfin driver
  i2c: remove bfin-twi driver
  spi: remove blackfin related host drivers
  watchdog: remove bfin_wdt driver
  can: remove bfin_can driver
  mmc: remove bfin_sdh driver
  input: misc: remove blackfin rotary driver
  input: keyboard: remove bf54x driver
  ...

1 files changed, 0 insertions, 683 deletions

diff --git a/arch/tile/kernel/backtrace.c b/arch/tile/kernel/backtrace.c
deleted file mode 100644
index f8b74ca83b925..0000000000000
--- a/arch/tile/kernel/backtrace.c
+++ /dev/null
@@ -1,683 +0,0 @@
-/*
- * Copyright 2011 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.
- */
-
-#include <linux/kernel.h>
-#include <linux/string.h>
-#include <asm/byteorder.h>
-#include <asm/backtrace.h>
-#include <asm/tile-desc.h>
-#include <arch/abi.h>
-
-#ifdef __tilegx__
-#define TILE_MAX_INSTRUCTIONS_PER_BUNDLE TILEGX_MAX_INSTRUCTIONS_PER_BUNDLE
-#define tile_decoded_instruction tilegx_decoded_instruction
-#define tile_mnemonic tilegx_mnemonic
-#define parse_insn_tile parse_insn_tilegx
-#define TILE_OPC_IRET TILEGX_OPC_IRET
-#define TILE_OPC_ADDI TILEGX_OPC_ADDI
-#define TILE_OPC_ADDLI TILEGX_OPC_ADDLI
-#define TILE_OPC_INFO TILEGX_OPC_INFO
-#define TILE_OPC_INFOL TILEGX_OPC_INFOL
-#define TILE_OPC_JRP TILEGX_OPC_JRP
-#define TILE_OPC_MOVE TILEGX_OPC_MOVE
-#define OPCODE_STORE TILEGX_OPC_ST
-typedef long long bt_int_reg_t;
-#else
-#define TILE_MAX_INSTRUCTIONS_PER_BUNDLE TILEPRO_MAX_INSTRUCTIONS_PER_BUNDLE
-#define tile_decoded_instruction tilepro_decoded_instruction
-#define tile_mnemonic tilepro_mnemonic
-#define parse_insn_tile parse_insn_tilepro
-#define TILE_OPC_IRET TILEPRO_OPC_IRET
-#define TILE_OPC_ADDI TILEPRO_OPC_ADDI
-#define TILE_OPC_ADDLI TILEPRO_OPC_ADDLI
-#define TILE_OPC_INFO TILEPRO_OPC_INFO
-#define TILE_OPC_INFOL TILEPRO_OPC_INFOL
-#define TILE_OPC_JRP TILEPRO_OPC_JRP
-#define TILE_OPC_MOVE TILEPRO_OPC_MOVE
-#define OPCODE_STORE TILEPRO_OPC_SW
-typedef int bt_int_reg_t;
-#endif
-
-/* A decoded bundle used for backtracer analysis. */
-struct BacktraceBundle {
-	tile_bundle_bits bits;
-	int num_insns;
-	struct tile_decoded_instruction
-	insns[TILE_MAX_INSTRUCTIONS_PER_BUNDLE];
-};
-
-
-/* Locates an instruction inside the given bundle that
- * has the specified mnemonic, and whose first 'num_operands_to_match'
- * operands exactly match those in 'operand_values'.
- */
-static const struct tile_decoded_instruction *find_matching_insn(
-	const struct BacktraceBundle *bundle,
-	tile_mnemonic mnemonic,
-	const int *operand_values,
-	int num_operands_to_match)
-{
-	int i, j;
-	bool match;
-
-	for (i = 0; i < bundle->num_insns; i++) {
-		const struct tile_decoded_instruction *insn =
-			&bundle->insns[i];
-
-		if (insn->opcode->mnemonic != mnemonic)
-			continue;
-
-		match = true;
-		for (j = 0; j < num_operands_to_match; j++) {
-			if (operand_values[j] != insn->operand_values[j]) {
-				match = false;
-				break;
-			}
-		}
-
-		if (match)
-			return insn;
-	}
-
-	return NULL;
-}
-
-/* Does this bundle contain an 'iret' instruction? */
-static inline bool bt_has_iret(const struct BacktraceBundle *bundle)
-{
-	return find_matching_insn(bundle, TILE_OPC_IRET, NULL, 0) != NULL;
-}
-
-/* Does this bundle contain an 'addi sp, sp, OFFSET' or
- * 'addli sp, sp, OFFSET' instruction, and if so, what is OFFSET?
- */
-static bool bt_has_addi_sp(const struct BacktraceBundle *bundle, int *adjust)
-{
-	static const int vals[2] = { TREG_SP, TREG_SP };
-
-	const struct tile_decoded_instruction *insn =
-		find_matching_insn(bundle, TILE_OPC_ADDI, vals, 2);
-	if (insn == NULL)
-		insn = find_matching_insn(bundle, TILE_OPC_ADDLI, vals, 2);
-#ifdef __tilegx__
-	if (insn == NULL)
-		insn = find_matching_insn(bundle, TILEGX_OPC_ADDXLI, vals, 2);
-	if (insn == NULL)
-		insn = find_matching_insn(bundle, TILEGX_OPC_ADDXI, vals, 2);
-#endif
-	if (insn == NULL)
-		return false;
-
-	*adjust = insn->operand_values[2];
-	return true;
-}
-
-/* Does this bundle contain any 'info OP' or 'infol OP'
- * instruction, and if so, what are their OP?  Note that OP is interpreted
- * as an unsigned value by this code since that's what the caller wants.
- * Returns the number of info ops found.
- */
-static int bt_get_info_ops(const struct BacktraceBundle *bundle,
-		int operands[MAX_INFO_OPS_PER_BUNDLE])
-{
-	int num_ops = 0;
-	int i;
-
-	for (i = 0; i < bundle->num_insns; i++) {
-		const struct tile_decoded_instruction *insn =
-			&bundle->insns[i];
-
-		if (insn->opcode->mnemonic == TILE_OPC_INFO ||
-		    insn->opcode->mnemonic == TILE_OPC_INFOL) {
-			operands[num_ops++] = insn->operand_values[0];
-		}
-	}
-
-	return num_ops;
-}
-
-/* Does this bundle contain a jrp instruction, and if so, to which
- * register is it jumping?
- */
-static bool bt_has_jrp(const struct BacktraceBundle *bundle, int *target_reg)
-{
-	const struct tile_decoded_instruction *insn =
-		find_matching_insn(bundle, TILE_OPC_JRP, NULL, 0);
-	if (insn == NULL)
-		return false;
-
-	*target_reg = insn->operand_values[0];
-	return true;
-}
-
-/* Does this bundle modify the specified register in any way? */
-static bool bt_modifies_reg(const struct BacktraceBundle *bundle, int reg)
-{
-	int i, j;
-	for (i = 0; i < bundle->num_insns; i++) {
-		const struct tile_decoded_instruction *insn =
-			&bundle->insns[i];
-
-		if (insn->opcode->implicitly_written_register == reg)
-			return true;
-
-		for (j = 0; j < insn->opcode->num_operands; j++)
-			if (insn->operands[j]->is_dest_reg &&
-			    insn->operand_values[j] == reg)
-				return true;
-	}
-
-	return false;
-}
-
-/* Does this bundle modify sp? */
-static inline bool bt_modifies_sp(const struct BacktraceBundle *bundle)
-{
-	return bt_modifies_reg(bundle, TREG_SP);
-}
-
-/* Does this bundle modify lr? */
-static inline bool bt_modifies_lr(const struct BacktraceBundle *bundle)
-{
-	return bt_modifies_reg(bundle, TREG_LR);
-}
-
-/* Does this bundle contain the instruction 'move fp, sp'? */
-static inline bool bt_has_move_r52_sp(const struct BacktraceBundle *bundle)
-{
-	static const int vals[2] = { 52, TREG_SP };
-	return find_matching_insn(bundle, TILE_OPC_MOVE, vals, 2) != NULL;
-}
-
-/* Does this bundle contain a store of lr to sp? */
-static inline bool bt_has_sw_sp_lr(const struct BacktraceBundle *bundle)
-{
-	static const int vals[2] = { TREG_SP, TREG_LR };
-	return find_matching_insn(bundle, OPCODE_STORE, vals, 2) != NULL;
-}
-
-#ifdef __tilegx__
-/* Track moveli values placed into registers. */
-static inline void bt_update_moveli(const struct BacktraceBundle *bundle,
-				    int moveli_args[])
-{
-	int i;
-	for (i = 0; i < bundle->num_insns; i++) {
-		const struct tile_decoded_instruction *insn =
-			&bundle->insns[i];
-
-		if (insn->opcode->mnemonic == TILEGX_OPC_MOVELI) {
-			int reg = insn->operand_values[0];
-			moveli_args[reg] = insn->operand_values[1];
-		}
-	}
-}
-
-/* Does this bundle contain an 'add sp, sp, reg' instruction
- * from a register that we saw a moveli into, and if so, what
- * is the value in the register?
- */
-static bool bt_has_add_sp(const struct BacktraceBundle *bundle, int *adjust,
-			  int moveli_args[])
-{
-	static const int vals[2] = { TREG_SP, TREG_SP };
-
-	const struct tile_decoded_instruction *insn =
-		find_matching_insn(bundle, TILEGX_OPC_ADDX, vals, 2);
-	if (insn) {
-		int reg = insn->operand_values[2];
-		if (moveli_args[reg]) {
-			*adjust = moveli_args[reg];
-			return true;
-		}
-	}
-	return false;
-}
-#endif
-
-/* Locates the caller's PC and SP for a program starting at the
- * given address.
- */
-static void find_caller_pc_and_caller_sp(CallerLocation *location,
-					 const unsigned long start_pc,
-					 BacktraceMemoryReader read_memory_func,
-					 void *read_memory_func_extra)
-{
-	/* Have we explicitly decided what the sp is,
-	 * rather than just the default?
-	 */
-	bool sp_determined = false;
-
-	/* Has any bundle seen so far modified lr? */
-	bool lr_modified = false;
-
-	/* Have we seen a move from sp to fp? */
-	bool sp_moved_to_r52 = false;
-
-	/* Have we seen a terminating bundle? */
-	bool seen_terminating_bundle = false;
-
-	/* Cut down on round-trip reading overhead by reading several
-	 * bundles at a time.
-	 */
-	tile_bundle_bits prefetched_bundles[32];
-	int num_bundles_prefetched = 0;
-	int next_bundle = 0;
-	unsigned long pc;
-
-#ifdef __tilegx__
-	/* Naively try to track moveli values to support addx for -m32. */
-	int moveli_args[TILEGX_NUM_REGISTERS] = { 0 };
-#endif
-
-	/* Default to assuming that the caller's sp is the current sp.
-	 * This is necessary to handle the case where we start backtracing
-	 * right at the end of the epilog.
-	 */
-	location->sp_location = SP_LOC_OFFSET;
-	location->sp_offset = 0;
-
-	/* Default to having no idea where the caller PC is. */
-	location->pc_location = PC_LOC_UNKNOWN;
-
-	/* Don't even try if the PC is not aligned. */
-	if (start_pc % TILE_BUNDLE_ALIGNMENT_IN_BYTES != 0)
-		return;
-
-	for (pc = start_pc;; pc += sizeof(tile_bundle_bits)) {
-
-		struct BacktraceBundle bundle;
-		int num_info_ops, info_operands[MAX_INFO_OPS_PER_BUNDLE];
-		int one_ago, jrp_reg;
-		bool has_jrp;
-
-		if (next_bundle >= num_bundles_prefetched) {
-			/* Prefetch some bytes, but don't cross a page
-			 * boundary since that might cause a read failure we
-			 * don't care about if we only need the first few
-			 * bytes. Note: we don't care what the actual page
-			 * size is; using the minimum possible page size will
-			 * prevent any problems.
-			 */
-			unsigned int bytes_to_prefetch = 4096 - (pc & 4095);
-			if (bytes_to_prefetch > sizeof prefetched_bundles)
-				bytes_to_prefetch = sizeof prefetched_bundles;
-
-			if (!read_memory_func(prefetched_bundles, pc,
-					      bytes_to_prefetch,
-					      read_memory_func_extra)) {
-				if (pc == start_pc) {
-					/* The program probably called a bad
-					 * address, such as a NULL pointer.
-					 * So treat this as if we are at the
-					 * start of the function prolog so the
-					 * backtrace will show how we got here.
-					 */
-					location->pc_location = PC_LOC_IN_LR;
-					return;
-				}
-
-				/* Unreadable address. Give up. */
-				break;
-			}
-
-			next_bundle = 0;
-			num_bundles_prefetched =
-				bytes_to_prefetch / sizeof(tile_bundle_bits);
-		}
-
-		/*
-		 * Decode the next bundle.
-		 * TILE always stores instruction bundles in little-endian
-		 * mode, even when the chip is running in big-endian mode.
-		 */
-		bundle.bits = le64_to_cpu(prefetched_bundles[next_bundle++]);
-		bundle.num_insns =
-			parse_insn_tile(bundle.bits, pc, bundle.insns);
-		num_info_ops = bt_get_info_ops(&bundle, info_operands);
-
-		/* First look at any one_ago info ops if they are interesting,
-		 * since they should shadow any non-one-ago info ops.
-		 */
-		for (one_ago = (pc != start_pc) ? 1 : 0;
-		     one_ago >= 0; one_ago--) {
-			int i;
-			for (i = 0; i < num_info_ops; i++) {
-				int info_operand = info_operands[i];
-				if (info_operand < CALLER_UNKNOWN_BASE)	{
-					/* Weird; reserved value, ignore it. */
-					continue;
-				}
-
-				/* Skip info ops which are not in the
-				 * "one_ago" mode we want right now.
-				 */
-				if (((info_operand & ONE_BUNDLE_AGO_FLAG) != 0)
-				    != (one_ago != 0))
-					continue;
-
-				/* Clear the flag to make later checking
-				 * easier. */
-				info_operand &= ~ONE_BUNDLE_AGO_FLAG;
-
-				/* Default to looking at PC_IN_LR_FLAG. */
-				if (info_operand & PC_IN_LR_FLAG)
-					location->pc_location =
-						PC_LOC_IN_LR;
-				else
-					location->pc_location =
-						PC_LOC_ON_STACK;
-
-				switch (info_operand) {
-				case CALLER_UNKNOWN_BASE:
-					location->pc_location = PC_LOC_UNKNOWN;
-					location->sp_location = SP_LOC_UNKNOWN;
-					return;
-
-				case CALLER_SP_IN_R52_BASE:
-				case CALLER_SP_IN_R52_BASE | PC_IN_LR_FLAG:
-					location->sp_location = SP_LOC_IN_R52;
-					return;
-
-				default:
-				{
-					const unsigned int val = info_operand
-						- CALLER_SP_OFFSET_BASE;
-					const unsigned int sp_offset =
-						(val >> NUM_INFO_OP_FLAGS) * 8;
-					if (sp_offset < 32768) {
-						/* This is a properly encoded
-						 * SP offset. */
-						location->sp_location =
-							SP_LOC_OFFSET;
-						location->sp_offset =
-							sp_offset;
-						return;
-					} else {
-						/* This looked like an SP
-						 * offset, but it's outside
-						 * the legal range, so this
-						 * must be an unrecognized
-						 * info operand.  Ignore it.
-						 */
-					}
-				}
-				break;
-				}
-			}
-		}
-
-		if (seen_terminating_bundle) {
-			/* We saw a terminating bundle during the previous
-			 * iteration, so we were only looking for an info op.
-			 */
-			break;
-		}
-
-		if (bundle.bits == 0) {
-			/* Wacky terminating bundle. Stop looping, and hope
-			 * we've already seen enough to find the caller.
-			 */
-			break;
-		}
-
-		/*
-		 * Try to determine caller's SP.
-		 */
-
-		if (!sp_determined) {
-			int adjust;
-			if (bt_has_addi_sp(&bundle, &adjust)
-#ifdef __tilegx__
-			    || bt_has_add_sp(&bundle, &adjust, moveli_args)
-#endif
-				) {
-				location->sp_location = SP_LOC_OFFSET;
-
-				if (adjust <= 0) {
-					/* We are in prolog about to adjust
-					 * SP. */
-					location->sp_offset = 0;
-				} else {
-					/* We are in epilog restoring SP. */
-					location->sp_offset = adjust;
-				}
-
-				sp_determined = true;
-			} else {
-				if (bt_has_move_r52_sp(&bundle)) {
-					/* Maybe in prolog, creating an
-					 * alloca-style frame.  But maybe in
-					 * the middle of a fixed-size frame
-					 * clobbering r52 with SP.
-					 */
-					sp_moved_to_r52 = true;
-				}
-
-				if (bt_modifies_sp(&bundle)) {
-					if (sp_moved_to_r52) {
-						/* We saw SP get saved into
-						 * r52 earlier (or now), which
-						 * must have been in the
-						 * prolog, so we now know that
-						 * SP is still holding the
-						 * caller's sp value.
-						 */
-						location->sp_location =
-							SP_LOC_OFFSET;
-						location->sp_offset = 0;
-					} else {
-						/* Someone must have saved
-						 * aside the caller's SP value
-						 * into r52, so r52 holds the
-						 * current value.
-						 */
-						location->sp_location =
-							SP_LOC_IN_R52;
-					}
-					sp_determined = true;
-				}
-			}
-
-#ifdef __tilegx__
-			/* Track moveli arguments for -m32 mode. */
-			bt_update_moveli(&bundle, moveli_args);
-#endif
-		}
-
-		if (bt_has_iret(&bundle)) {
-			/* This is a terminating bundle. */
-			seen_terminating_bundle = true;
-			continue;
-		}
-
-		/*
-		 * Try to determine caller's PC.
-		 */
-
-		jrp_reg = -1;
-		has_jrp = bt_has_jrp(&bundle, &jrp_reg);
-		if (has_jrp)
-			seen_terminating_bundle = true;
-
-		if (location->pc_location == PC_LOC_UNKNOWN) {
-			if (has_jrp) {
-				if (jrp_reg == TREG_LR && !lr_modified) {
-					/* Looks like a leaf function, or else
-					 * lr is already restored. */
-					location->pc_location =
-						PC_LOC_IN_LR;
-				} else {
-					location->pc_location =
-						PC_LOC_ON_STACK;
-				}
-			} else if (bt_has_sw_sp_lr(&bundle)) {
-				/* In prolog, spilling initial lr to stack. */
-				location->pc_location = PC_LOC_IN_LR;
-			} else if (bt_modifies_lr(&bundle)) {
-				lr_modified = true;
-			}
-		}
-	}
-}
-
-/* Initializes a backtracer to start from the given location.
- *
- * If the frame pointer cannot be determined it is set to -1.
- *
- * state: The state to be filled in.
- * read_memory_func: A callback that reads memory.
- * read_memory_func_extra: An arbitrary argument to read_memory_func.
- * pc: The current PC.
- * lr: The current value of the 'lr' register.
- * sp: The current value of the 'sp' register.
- * r52: The current value of the 'r52' register.
- */
-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)
-{
-	CallerLocation location;
-	unsigned long fp, initial_frame_caller_pc;
-
-	/* Find out where we are in the initial frame. */
-	find_caller_pc_and_caller_sp(&location, pc,
-				     read_memory_func, read_memory_func_extra);
-
-	switch (location.sp_location) {
-	case SP_LOC_UNKNOWN:
-		/* Give up. */
-		fp = -1;
-		break;
-
-	case SP_LOC_IN_R52:
-		fp = r52;
-		break;
-
-	case SP_LOC_OFFSET:
-		fp = sp + location.sp_offset;
-		break;
-
-	default:
-		/* Give up. */
-		fp = -1;
-		break;
-	}
-
-	/* If the frame pointer is not aligned to the basic word size
-	 * something terrible happened and we should mark it as invalid.
-	 */
-	if (fp % sizeof(bt_int_reg_t) != 0)
-		fp = -1;
-
-	/* -1 means "don't know initial_frame_caller_pc". */
-	initial_frame_caller_pc = -1;
-
-	switch (location.pc_location) {
-	case PC_LOC_UNKNOWN:
-		/* Give up. */
-		fp = -1;
-		break;
-
-	case PC_LOC_IN_LR:
-		if (lr == 0 || lr % TILE_BUNDLE_ALIGNMENT_IN_BYTES != 0) {
-			/* Give up. */
-			fp = -1;
-		} else {
-			initial_frame_caller_pc = lr;
-		}
-		break;
-
-	case PC_LOC_ON_STACK:
-		/* Leave initial_frame_caller_pc as -1,
-		 * meaning check the stack.
-		 */
-		break;
-
-	default:
-		/* Give up. */
-		fp = -1;
-		break;
-	}
-
-	state->pc = pc;
-	state->sp = sp;
-	state->fp = fp;
-	state->initial_frame_caller_pc = initial_frame_caller_pc;
-	state->read_memory_func = read_memory_func;
-	state->read_memory_func_extra = read_memory_func_extra;
-}
-
-/* Handle the case where the register holds more bits than the VA. */
-static bool valid_addr_reg(bt_int_reg_t reg)
-{
-	return ((unsigned long)reg == reg);
-}
-
-/* Advances the backtracing state to the calling frame, returning
- * true iff successful.
- */
-bool backtrace_next(BacktraceIterator *state)
-{
-	unsigned long next_fp, next_pc;
-	bt_int_reg_t next_frame[2];
-
-	if (state->fp == -1) {
-		/* No parent frame. */
-		return false;
-	}
-
-	/* Try to read the frame linkage data chaining to the next function. */
-	if (!state->read_memory_func(&next_frame, state->fp, sizeof next_frame,
-				     state->read_memory_func_extra)) {
-		return false;
-	}
-
-	next_fp = next_frame[1];
-	if (!valid_addr_reg(next_frame[1]) ||
-	    next_fp % sizeof(bt_int_reg_t) != 0) {
-		/* Caller's frame pointer is suspect, so give up. */
-		return false;
-	}
-
-	if (state->initial_frame_caller_pc != -1) {
-		/* We must be in the initial stack frame and already know the
-		 * caller PC.
-		 */
-		next_pc = state->initial_frame_caller_pc;
-
-		/* Force reading stack next time, in case we were in the
-		 * initial frame.  We don't do this above just to paranoidly
-		 * avoid changing the struct at all when we return false.
-		 */
-		state->initial_frame_caller_pc = -1;
-	} else {
-		/* Get the caller PC from the frame linkage area. */
-		next_pc = next_frame[0];
-		if (!valid_addr_reg(next_frame[0]) || next_pc == 0 ||
-		    next_pc % TILE_BUNDLE_ALIGNMENT_IN_BYTES != 0) {
-			/* The PC is suspect, so give up. */
-			return false;
-		}
-	}
-
-	/* Update state to become the caller's stack frame. */
-	state->pc = next_pc;
-	state->sp = state->fp;
-	state->fp = next_fp;
-
-	return true;
-}