arch: remove tile port

The Tile architecture port was added by Chris Metcalf in 2010, and
maintained until early 2018 when he orphaned it due to his departure
from Mellanox, and nobody else stepped up to maintain it. The product
line is still around in the form of the BlueField SoC, but no longer
uses the Tile architecture.

There are also still products for sale with Tile-GX SoCs, notably the
Mikrotik CCR router family. The products all use old (linux-3.3) kernels
with lots of patches and won't be upgraded by their manufacturers. There
have been efforts to port both OpenWRT and Debian to these, but both
projects have stalled and are very unlikely to be continued in the future.

Given that we are reasonably sure that nobody is still using the port
with an upstream kernel any more, it seems better to remove it now while
the port is in a good shape than to let it bitrot for a few years first.

Cc: Chris Metcalf <chris.d.metcalf@gmail.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: http://www.mellanox.com/page/npu_multicore_overview
Link: https://jenkins.debian.net/view/rebootstrap/job/rebootstrap_tilegx_gcc7/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 0 insertions, 527 deletions

diff --git a/arch/tile/kernel/kprobes.c b/arch/tile/kernel/kprobes.c
deleted file mode 100644
index c68694bb1ad2..000000000000
--- a/arch/tile/kernel/kprobes.c
+++ /dev/null
@@ -1,527 +0,0 @@
-/*
- * arch/tile/kernel/kprobes.c
- * Kprobes on TILE-Gx
- *
- * Some portions copied from the MIPS version.
- *
- * Copyright (C) IBM Corporation, 2002, 2004
- * Copyright 2006 Sony Corp.
- * Copyright 2010 Cavium Networks
- *
- * Copyright 2012 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/kprobes.h>
-#include <linux/kdebug.h>
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/uaccess.h>
-#include <asm/cacheflush.h>
-
-#include <arch/opcode.h>
-
-DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
-DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
-
-tile_bundle_bits breakpoint_insn = TILEGX_BPT_BUNDLE;
-tile_bundle_bits breakpoint2_insn = TILEGX_BPT_BUNDLE | DIE_SSTEPBP;
-
-/*
- * Check whether instruction is branch or jump, or if executing it
- * has different results depending on where it is executed (e.g. lnk).
- */
-static int __kprobes insn_has_control(kprobe_opcode_t insn)
-{
-	if (get_Mode(insn) != 0) {   /* Y-format bundle */
-		if (get_Opcode_Y1(insn) != RRR_1_OPCODE_Y1 ||
-		    get_RRROpcodeExtension_Y1(insn) != UNARY_RRR_1_OPCODE_Y1)
-			return 0;
-
-		switch (get_UnaryOpcodeExtension_Y1(insn)) {
-		case JALRP_UNARY_OPCODE_Y1:
-		case JALR_UNARY_OPCODE_Y1:
-		case JRP_UNARY_OPCODE_Y1:
-		case JR_UNARY_OPCODE_Y1:
-		case LNK_UNARY_OPCODE_Y1:
-			return 1;
-		default:
-			return 0;
-		}
-	}
-
-	switch (get_Opcode_X1(insn)) {
-	case BRANCH_OPCODE_X1:	/* branch instructions */
-	case JUMP_OPCODE_X1:	/* jump instructions: j and jal */
-		return 1;
-
-	case RRR_0_OPCODE_X1:   /* other jump instructions */
-		if (get_RRROpcodeExtension_X1(insn) != UNARY_RRR_0_OPCODE_X1)
-			return 0;
-		switch (get_UnaryOpcodeExtension_X1(insn)) {
-		case JALRP_UNARY_OPCODE_X1:
-		case JALR_UNARY_OPCODE_X1:
-		case JRP_UNARY_OPCODE_X1:
-		case JR_UNARY_OPCODE_X1:
-		case LNK_UNARY_OPCODE_X1:
-			return 1;
-		default:
-			return 0;
-		}
-	default:
-		return 0;
-	}
-}
-
-int __kprobes arch_prepare_kprobe(struct kprobe *p)
-{
-	unsigned long addr = (unsigned long)p->addr;
-
-	if (addr & (sizeof(kprobe_opcode_t) - 1))
-		return -EINVAL;
-
-	if (insn_has_control(*p->addr)) {
-		pr_notice("Kprobes for control instructions are not supported\n");
-		return -EINVAL;
-	}
-
-	/* insn: must be on special executable page on tile. */
-	p->ainsn.insn = get_insn_slot();
-	if (!p->ainsn.insn)
-		return -ENOMEM;
-
-	/*
-	 * In the kprobe->ainsn.insn[] array we store the original
-	 * instruction at index zero and a break trap instruction at
-	 * index one.
-	 */
-	memcpy(&p->ainsn.insn[0], p->addr, sizeof(kprobe_opcode_t));
-	p->ainsn.insn[1] = breakpoint2_insn;
-	p->opcode = *p->addr;
-
-	return 0;
-}
-
-void __kprobes arch_arm_kprobe(struct kprobe *p)
-{
-	unsigned long addr_wr;
-
-	/* Operate on writable kernel text mapping. */
-	addr_wr = ktext_writable_addr(p->addr);
-
-	if (probe_kernel_write((void *)addr_wr, &breakpoint_insn,
-		sizeof(breakpoint_insn)))
-		pr_err("%s: failed to enable kprobe\n", __func__);
-
-	smp_wmb();
-	flush_insn_slot(p);
-}
-
-void __kprobes arch_disarm_kprobe(struct kprobe *kp)
-{
-	unsigned long addr_wr;
-
-	/* Operate on writable kernel text mapping. */
-	addr_wr = ktext_writable_addr(kp->addr);
-
-	if (probe_kernel_write((void *)addr_wr, &kp->opcode,
-		sizeof(kp->opcode)))
-		pr_err("%s: failed to enable kprobe\n", __func__);
-
-	smp_wmb();
-	flush_insn_slot(kp);
-}
-
-void __kprobes arch_remove_kprobe(struct kprobe *p)
-{
-	if (p->ainsn.insn) {
-		free_insn_slot(p->ainsn.insn, 0);
-		p->ainsn.insn = NULL;
-	}
-}
-
-static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
-{
-	kcb->prev_kprobe.kp = kprobe_running();
-	kcb->prev_kprobe.status = kcb->kprobe_status;
-	kcb->prev_kprobe.saved_pc = kcb->kprobe_saved_pc;
-}
-
-static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
-{
-	__this_cpu_write(current_kprobe, kcb->prev_kprobe.kp);
-	kcb->kprobe_status = kcb->prev_kprobe.status;
-	kcb->kprobe_saved_pc = kcb->prev_kprobe.saved_pc;
-}
-
-static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
-			struct kprobe_ctlblk *kcb)
-{
-	__this_cpu_write(current_kprobe, p);
-	kcb->kprobe_saved_pc = regs->pc;
-}
-
-static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
-{
-	/* Single step inline if the instruction is a break. */
-	if (p->opcode == breakpoint_insn ||
-	    p->opcode == breakpoint2_insn)
-		regs->pc = (unsigned long)p->addr;
-	else
-		regs->pc = (unsigned long)&p->ainsn.insn[0];
-}
-
-static int __kprobes kprobe_handler(struct pt_regs *regs)
-{
-	struct kprobe *p;
-	int ret = 0;
-	kprobe_opcode_t *addr;
-	struct kprobe_ctlblk *kcb;
-
-	addr = (kprobe_opcode_t *)regs->pc;
-
-	/*
-	 * We don't want to be preempted for the entire
-	 * duration of kprobe processing.
-	 */
-	preempt_disable();
-	kcb = get_kprobe_ctlblk();
-
-	/* Check we're not actually recursing. */
-	if (kprobe_running()) {
-		p = get_kprobe(addr);
-		if (p) {
-			if (kcb->kprobe_status == KPROBE_HIT_SS &&
-			    p->ainsn.insn[0] == breakpoint_insn) {
-				goto no_kprobe;
-			}
-			/*
-			 * We have reentered the kprobe_handler(), since
-			 * another probe was hit while within the handler.
-			 * We here save the original kprobes variables and
-			 * just single step on the instruction of the new probe
-			 * without calling any user handlers.
-			 */
-			save_previous_kprobe(kcb);
-			set_current_kprobe(p, regs, kcb);
-			kprobes_inc_nmissed_count(p);
-			prepare_singlestep(p, regs);
-			kcb->kprobe_status = KPROBE_REENTER;
-			return 1;
-		} else {
-			if (*addr != breakpoint_insn) {
-				/*
-				 * The breakpoint instruction was removed by
-				 * another cpu right after we hit, no further
-				 * handling of this interrupt is appropriate.
-				 */
-				ret = 1;
-				goto no_kprobe;
-			}
-			p = __this_cpu_read(current_kprobe);
-			if (p->break_handler && p->break_handler(p, regs))
-				goto ss_probe;
-		}
-		goto no_kprobe;
-	}
-
-	p = get_kprobe(addr);
-	if (!p) {
-		if (*addr != breakpoint_insn) {
-			/*
-			 * The breakpoint instruction was removed right
-			 * after we hit it.  Another cpu has removed
-			 * either a probepoint or a debugger breakpoint
-			 * at this address.  In either case, no further
-			 * handling of this interrupt is appropriate.
-			 */
-			ret = 1;
-		}
-		/* Not one of ours: let kernel handle it. */
-		goto no_kprobe;
-	}
-
-	set_current_kprobe(p, regs, kcb);
-	kcb->kprobe_status = KPROBE_HIT_ACTIVE;
-
-	if (p->pre_handler && p->pre_handler(p, regs)) {
-		/* Handler has already set things up, so skip ss setup. */
-		return 1;
-	}
-
-ss_probe:
-	prepare_singlestep(p, regs);
-	kcb->kprobe_status = KPROBE_HIT_SS;
-	return 1;
-
-no_kprobe:
-	preempt_enable_no_resched();
-	return ret;
-}
-
-/*
- * Called after single-stepping.  p->addr is the address of the
- * instruction that has been replaced by the breakpoint. To avoid the
- * SMP problems that can occur when we temporarily put back the
- * original opcode to single-step, we single-stepped a copy of the
- * instruction.  The address of this copy is p->ainsn.insn.
- *
- * This function prepares to return from the post-single-step
- * breakpoint trap.
- */
-static void __kprobes resume_execution(struct kprobe *p,
-				       struct pt_regs *regs,
-				       struct kprobe_ctlblk *kcb)
-{
-	unsigned long orig_pc = kcb->kprobe_saved_pc;
-	regs->pc = orig_pc + 8;
-}
-
-static inline int post_kprobe_handler(struct pt_regs *regs)
-{
-	struct kprobe *cur = kprobe_running();
-	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
-	if (!cur)
-		return 0;
-
-	if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
-		kcb->kprobe_status = KPROBE_HIT_SSDONE;
-		cur->post_handler(cur, regs, 0);
-	}
-
-	resume_execution(cur, regs, kcb);
-
-	/* Restore back the original saved kprobes variables and continue. */
-	if (kcb->kprobe_status == KPROBE_REENTER) {
-		restore_previous_kprobe(kcb);
-		goto out;
-	}
-	reset_current_kprobe();
-out:
-	preempt_enable_no_resched();
-
-	return 1;
-}
-
-static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
-{
-	struct kprobe *cur = kprobe_running();
-	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
-	if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
-		return 1;
-
-	if (kcb->kprobe_status & KPROBE_HIT_SS) {
-		/*
-		 * We are here because the instruction being single
-		 * stepped caused a page fault. We reset the current
-		 * kprobe and the ip points back to the probe address
-		 * and allow the page fault handler to continue as a
-		 * normal page fault.
-		 */
-		resume_execution(cur, regs, kcb);
-		reset_current_kprobe();
-		preempt_enable_no_resched();
-	}
-	return 0;
-}
-
-/*
- * Wrapper routine for handling exceptions.
- */
-int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
-				       unsigned long val, void *data)
-{
-	struct die_args *args = (struct die_args *)data;
-	int ret = NOTIFY_DONE;
-
-	switch (val) {
-	case DIE_BREAK:
-		if (kprobe_handler(args->regs))
-			ret = NOTIFY_STOP;
-		break;
-	case DIE_SSTEPBP:
-		if (post_kprobe_handler(args->regs))
-			ret = NOTIFY_STOP;
-		break;
-	case DIE_PAGE_FAULT:
-		/* kprobe_running() needs smp_processor_id(). */
-		preempt_disable();
-
-		if (kprobe_running()
-		    && kprobe_fault_handler(args->regs, args->trapnr))
-			ret = NOTIFY_STOP;
-		preempt_enable();
-		break;
-	default:
-		break;
-	}
-	return ret;
-}
-
-int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
-{
-	struct jprobe *jp = container_of(p, struct jprobe, kp);
-	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
-	kcb->jprobe_saved_regs = *regs;
-	kcb->jprobe_saved_sp = regs->sp;
-
-	memcpy(kcb->jprobes_stack, (void *)kcb->jprobe_saved_sp,
-	       MIN_JPROBES_STACK_SIZE(kcb->jprobe_saved_sp));
-
-	regs->pc = (unsigned long)(jp->entry);
-
-	return 1;
-}
-
-/* Defined in the inline asm below. */
-void jprobe_return_end(void);
-
-void __kprobes jprobe_return(void)
-{
-	asm volatile(
-		"bpt\n\t"
-		".globl jprobe_return_end\n"
-		"jprobe_return_end:\n");
-}
-
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
-	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-
-	if (regs->pc >= (unsigned long)jprobe_return &&
-	    regs->pc <= (unsigned long)jprobe_return_end) {
-		*regs = kcb->jprobe_saved_regs;
-		memcpy((void *)kcb->jprobe_saved_sp, kcb->jprobes_stack,
-		       MIN_JPROBES_STACK_SIZE(kcb->jprobe_saved_sp));
-		preempt_enable_no_resched();
-
-		return 1;
-	}
-	return 0;
-}
-
-/*
- * Function return probe trampoline:
- * - init_kprobes() establishes a probepoint here
- * - When the probed function returns, this probe causes the
- *   handlers to fire
- */
-static void __used kretprobe_trampoline_holder(void)
-{
-	asm volatile(
-		"nop\n\t"
-		".global kretprobe_trampoline\n"
-		"kretprobe_trampoline:\n\t"
-		"nop\n\t"
-		: : : "memory");
-}
-
-void kretprobe_trampoline(void);
-
-void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
-				      struct pt_regs *regs)
-{
-	ri->ret_addr = (kprobe_opcode_t *) regs->lr;
-
-	/* Replace the return addr with trampoline addr */
-	regs->lr = (unsigned long)kretprobe_trampoline;
-}
-
-/*
- * Called when the probe at kretprobe trampoline is hit.
- */
-static int __kprobes trampoline_probe_handler(struct kprobe *p,
-						struct pt_regs *regs)
-{
-	struct kretprobe_instance *ri = NULL;
-	struct hlist_head *head, empty_rp;
-	struct hlist_node *tmp;
-	unsigned long flags, orig_ret_address = 0;
-	unsigned long trampoline_address = (unsigned long)kretprobe_trampoline;
-
-	INIT_HLIST_HEAD(&empty_rp);
-	kretprobe_hash_lock(current, &head, &flags);
-
-	/*
-	 * It is possible to have multiple instances associated with a given
-	 * task either because multiple functions in the call path have
-	 * a return probe installed on them, and/or more than one return
-	 * return probe was registered for a target function.
-	 *
-	 * We can handle this because:
-	 *     - instances are always inserted at the head of the list
-	 *     - when multiple return probes are registered for the same
-	 *       function, the first instance's ret_addr will point to the
-	 *       real return address, and all the rest will point to
-	 *       kretprobe_trampoline
-	 */
-	hlist_for_each_entry_safe(ri, tmp, head, hlist) {
-		if (ri->task != current)
-			/* another task is sharing our hash bucket */
-			continue;
-
-		if (ri->rp && ri->rp->handler)
-			ri->rp->handler(ri, regs);
-
-		orig_ret_address = (unsigned long)ri->ret_addr;
-		recycle_rp_inst(ri, &empty_rp);
-
-		if (orig_ret_address != trampoline_address) {
-			/*
-			 * This is the real return address. Any other
-			 * instances associated with this task are for
-			 * other calls deeper on the call stack
-			 */
-			break;
-		}
-	}
-
-	kretprobe_assert(ri, orig_ret_address, trampoline_address);
-	instruction_pointer(regs) = orig_ret_address;
-
-	reset_current_kprobe();
-	kretprobe_hash_unlock(current, &flags);
-	preempt_enable_no_resched();
-
-	hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) {
-		hlist_del(&ri->hlist);
-		kfree(ri);
-	}
-	/*
-	 * By returning a non-zero value, we are telling
-	 * kprobe_handler() that we don't want the post_handler
-	 * to run (and have re-enabled preemption)
-	 */
-	return 1;
-}
-
-int __kprobes arch_trampoline_kprobe(struct kprobe *p)
-{
-	if (p->addr == (kprobe_opcode_t *)kretprobe_trampoline)
-		return 1;
-
-	return 0;
-}
-
-static struct kprobe trampoline_p = {
-	.addr = (kprobe_opcode_t *)kretprobe_trampoline,
-	.pre_handler = trampoline_probe_handler
-};
-
-int __init arch_init_kprobes(void)
-{
-	register_kprobe(&trampoline_p);
-	return 0;
-}