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, 316 deletions

diff --git a/arch/tile/kernel/ptrace.c b/arch/tile/kernel/ptrace.c
deleted file mode 100644
index d516d61751c2..000000000000
--- a/arch/tile/kernel/ptrace.c
+++ /dev/null
@@ -1,316 +0,0 @@
-/*
- * 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.
- *
- * Copied from i386: Ross Biro 1/23/92
- */
-
-#include <linux/kernel.h>
-#include <linux/ptrace.h>
-#include <linux/kprobes.h>
-#include <linux/compat.h>
-#include <linux/uaccess.h>
-#include <linux/regset.h>
-#include <linux/elf.h>
-#include <linux/tracehook.h>
-#include <linux/context_tracking.h>
-#include <linux/sched/task_stack.h>
-
-#include <asm/traps.h>
-#include <arch/chip.h>
-
-#define CREATE_TRACE_POINTS
-#include <trace/events/syscalls.h>
-
-void user_enable_single_step(struct task_struct *child)
-{
-	set_tsk_thread_flag(child, TIF_SINGLESTEP);
-}
-
-void user_disable_single_step(struct task_struct *child)
-{
-	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
-}
-
-/*
- * Called by kernel/ptrace.c when detaching..
- */
-void ptrace_disable(struct task_struct *child)
-{
-	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
-
-	/*
-	 * These two are currently unused, but will be set by arch_ptrace()
-	 * and used in the syscall assembly when we do support them.
-	 */
-	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
-}
-
-/*
- * Get registers from task and ready the result for userspace.
- * Note that we localize the API issues to getregs() and putregs() at
- * some cost in performance, e.g. we need a full pt_regs copy for
- * PEEKUSR, and two copies for POKEUSR.  But in general we expect
- * GETREGS/PUTREGS to be the API of choice anyway.
- */
-static char *getregs(struct task_struct *child, struct pt_regs *uregs)
-{
-	*uregs = *task_pt_regs(child);
-
-	/* Set up flags ABI bits. */
-	uregs->flags = 0;
-#ifdef CONFIG_COMPAT
-	if (task_thread_info(child)->status & TS_COMPAT)
-		uregs->flags |= PT_FLAGS_COMPAT;
-#endif
-
-	return (char *)uregs;
-}
-
-/* Put registers back to task. */
-static void putregs(struct task_struct *child, struct pt_regs *uregs)
-{
-	struct pt_regs *regs = task_pt_regs(child);
-
-	/* Don't allow overwriting the kernel-internal flags word. */
-	uregs->flags = regs->flags;
-
-	/* Only allow setting the ICS bit in the ex1 word. */
-	uregs->ex1 = PL_ICS_EX1(USER_PL, EX1_ICS(uregs->ex1));
-
-	*regs = *uregs;
-}
-
-enum tile_regset {
-	REGSET_GPR,
-};
-
-static int tile_gpr_get(struct task_struct *target,
-			  const struct user_regset *regset,
-			  unsigned int pos, unsigned int count,
-			  void *kbuf, void __user *ubuf)
-{
-	struct pt_regs regs;
-
-	getregs(target, &regs);
-
-	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, &regs, 0,
-				   sizeof(regs));
-}
-
-static int tile_gpr_set(struct task_struct *target,
-			  const struct user_regset *regset,
-			  unsigned int pos, unsigned int count,
-			  const void *kbuf, const void __user *ubuf)
-{
-	int ret;
-	struct pt_regs regs = *task_pt_regs(target);
-
-	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0,
-				 sizeof(regs));
-	if (ret)
-		return ret;
-
-	putregs(target, &regs);
-
-	return 0;
-}
-
-static const struct user_regset tile_user_regset[] = {
-	[REGSET_GPR] = {
-		.core_note_type = NT_PRSTATUS,
-		.n = ELF_NGREG,
-		.size = sizeof(elf_greg_t),
-		.align = sizeof(elf_greg_t),
-		.get = tile_gpr_get,
-		.set = tile_gpr_set,
-	},
-};
-
-static const struct user_regset_view tile_user_regset_view = {
-	.name = CHIP_ARCH_NAME,
-	.e_machine = ELF_ARCH,
-	.ei_osabi = ELF_OSABI,
-	.regsets = tile_user_regset,
-	.n = ARRAY_SIZE(tile_user_regset),
-};
-
-const struct user_regset_view *task_user_regset_view(struct task_struct *task)
-{
-	return &tile_user_regset_view;
-}
-
-long arch_ptrace(struct task_struct *child, long request,
-		 unsigned long addr, unsigned long data)
-{
-	unsigned long __user *datap = (long __user __force *)data;
-	unsigned long tmp;
-	long ret = -EIO;
-	char *childreg;
-	struct pt_regs copyregs;
-
-	switch (request) {
-
-	case PTRACE_PEEKUSR:  /* Read register from pt_regs. */
-		if (addr >= PTREGS_SIZE)
-			break;
-		childreg = getregs(child, &copyregs) + addr;
-#ifdef CONFIG_COMPAT
-		if (is_compat_task()) {
-			if (addr & (sizeof(compat_long_t)-1))
-				break;
-			ret = put_user(*(compat_long_t *)childreg,
-				       (compat_long_t __user *)datap);
-		} else
-#endif
-		{
-			if (addr & (sizeof(long)-1))
-				break;
-			ret = put_user(*(long *)childreg, datap);
-		}
-		break;
-
-	case PTRACE_POKEUSR:  /* Write register in pt_regs. */
-		if (addr >= PTREGS_SIZE)
-			break;
-		childreg = getregs(child, &copyregs) + addr;
-#ifdef CONFIG_COMPAT
-		if (is_compat_task()) {
-			if (addr & (sizeof(compat_long_t)-1))
-				break;
-			*(compat_long_t *)childreg = data;
-		} else
-#endif
-		{
-			if (addr & (sizeof(long)-1))
-				break;
-			*(long *)childreg = data;
-		}
-		putregs(child, &copyregs);
-		ret = 0;
-		break;
-
-	case PTRACE_GETREGS:  /* Get all registers from the child. */
-		ret = copy_regset_to_user(child, &tile_user_regset_view,
-					  REGSET_GPR, 0,
-					  sizeof(struct pt_regs), datap);
-		break;
-
-	case PTRACE_SETREGS:  /* Set all registers in the child. */
-		ret = copy_regset_from_user(child, &tile_user_regset_view,
-					    REGSET_GPR, 0,
-					    sizeof(struct pt_regs), datap);
-		break;
-
-	case PTRACE_GETFPREGS:  /* Get the child FPU state. */
-	case PTRACE_SETFPREGS:  /* Set the child FPU state. */
-		break;
-
-	case PTRACE_SETOPTIONS:
-		/* Support TILE-specific ptrace options. */
-		BUILD_BUG_ON(PTRACE_O_MASK_TILE & PTRACE_O_MASK);
-		tmp = data & PTRACE_O_MASK_TILE;
-		data &= ~PTRACE_O_MASK_TILE;
-		ret = ptrace_request(child, request, addr, data);
-		if (ret == 0) {
-			unsigned int flags = child->ptrace;
-			flags &= ~(PTRACE_O_MASK_TILE << PT_OPT_FLAG_SHIFT);
-			flags |= (tmp << PT_OPT_FLAG_SHIFT);
-			child->ptrace = flags;
-		}
-		break;
-
-	default:
-#ifdef CONFIG_COMPAT
-		if (task_thread_info(current)->status & TS_COMPAT) {
-			ret = compat_ptrace_request(child, request,
-						    addr, data);
-			break;
-		}
-#endif
-		ret = ptrace_request(child, request, addr, data);
-		break;
-	}
-
-	return ret;
-}
-
-#ifdef CONFIG_COMPAT
-/* Not used; we handle compat issues in arch_ptrace() directly. */
-long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
-			       compat_ulong_t addr, compat_ulong_t data)
-{
-	BUG();
-}
-#endif
-
-int do_syscall_trace_enter(struct pt_regs *regs)
-{
-	u32 work = READ_ONCE(current_thread_info()->flags);
-
-	if ((work & _TIF_SYSCALL_TRACE) &&
-	    tracehook_report_syscall_entry(regs)) {
-		regs->regs[TREG_SYSCALL_NR] = -1;
-		return -1;
-	}
-
-	if (secure_computing(NULL) == -1)
-		return -1;
-
-	if (work & _TIF_SYSCALL_TRACEPOINT)
-		trace_sys_enter(regs, regs->regs[TREG_SYSCALL_NR]);
-
-	return regs->regs[TREG_SYSCALL_NR];
-}
-
-void do_syscall_trace_exit(struct pt_regs *regs)
-{
-	long errno;
-
-	/*
-	 * The standard tile calling convention returns the value (or negative
-	 * errno) in r0, and zero (or positive errno) in r1.
-	 * It saves a couple of cycles on the hot path to do this work in
-	 * registers only as we return, rather than updating the in-memory
-	 * struct ptregs.
-	 */
-	errno = (long) regs->regs[0];
-	if (errno < 0 && errno > -4096)
-		regs->regs[1] = -errno;
-	else
-		regs->regs[1] = 0;
-
-	if (test_thread_flag(TIF_SYSCALL_TRACE))
-		tracehook_report_syscall_exit(regs, 0);
-
-	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
-		trace_sys_exit(regs, regs->regs[0]);
-}
-
-void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs)
-{
-	struct siginfo info;
-
-	memset(&info, 0, sizeof(info));
-	info.si_signo = SIGTRAP;
-	info.si_code  = TRAP_BRKPT;
-	info.si_addr  = (void __user *) regs->pc;
-
-	/* Send us the fakey SIGTRAP */
-	force_sig_info(SIGTRAP, &info, tsk);
-}
-
-/* Handle synthetic interrupt delivered only by the simulator. */
-void __kprobes do_breakpoint(struct pt_regs* regs, int fault_num)
-{
-	send_sigtrap(current, regs);
-}