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, 421 deletions

diff --git a/arch/tile/kernel/traps.c b/arch/tile/kernel/traps.c
deleted file mode 100644
index 83a7186198d7..000000000000
--- a/arch/tile/kernel/traps.c
+++ /dev/null
@@ -1,421 +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.
- */
-
-#include <linux/sched.h>
-#include <linux/sched/debug.h>
-#include <linux/kernel.h>
-#include <linux/kprobes.h>
-#include <linux/kdebug.h>
-#include <linux/module.h>
-#include <linux/reboot.h>
-#include <linux/uaccess.h>
-#include <linux/ptrace.h>
-#include <linux/hardirq.h>
-#include <linux/nmi.h>
-#include <asm/stack.h>
-#include <asm/traps.h>
-#include <asm/setup.h>
-
-#include <arch/interrupts.h>
-#include <arch/spr_def.h>
-#include <arch/opcode.h>
-
-void __init trap_init(void)
-{
-	/* Nothing needed here since we link code at .intrpt */
-}
-
-int unaligned_fixup = 1;
-
-static int __init setup_unaligned_fixup(char *str)
-{
-	/*
-	 * Say "=-1" to completely disable it.  If you just do "=0", we
-	 * will still parse the instruction, then fire a SIGBUS with
-	 * the correct address from inside the single_step code.
-	 */
-	if (kstrtoint(str, 0, &unaligned_fixup) != 0)
-		return 0;
-
-	pr_info("Fixups for unaligned data accesses are %s\n",
-		unaligned_fixup >= 0 ?
-		(unaligned_fixup ? "enabled" : "disabled") :
-		"completely disabled");
-	return 1;
-}
-__setup("unaligned_fixup=", setup_unaligned_fixup);
-
-#if CHIP_HAS_TILE_DMA()
-
-static int dma_disabled;
-
-static int __init nodma(char *str)
-{
-	pr_info("User-space DMA is disabled\n");
-	dma_disabled = 1;
-	return 1;
-}
-__setup("nodma", nodma);
-
-/* How to decode SPR_GPV_REASON */
-#define IRET_ERROR (1U << 31)
-#define MT_ERROR   (1U << 30)
-#define MF_ERROR   (1U << 29)
-#define SPR_INDEX  ((1U << 15) - 1)
-#define SPR_MPL_SHIFT  9  /* starting bit position for MPL encoded in SPR */
-
-/*
- * See if this GPV is just to notify the kernel of SPR use and we can
- * retry the user instruction after adjusting some MPLs suitably.
- */
-static int retry_gpv(unsigned int gpv_reason)
-{
-	int mpl;
-
-	if (gpv_reason & IRET_ERROR)
-		return 0;
-
-	BUG_ON((gpv_reason & (MT_ERROR|MF_ERROR)) == 0);
-	mpl = (gpv_reason & SPR_INDEX) >> SPR_MPL_SHIFT;
-	if (mpl == INT_DMA_NOTIFY && !dma_disabled) {
-		/* User is turning on DMA. Allow it and retry. */
-		printk(KERN_DEBUG "Process %d/%s is now enabled for DMA\n",
-		       current->pid, current->comm);
-		BUG_ON(current->thread.tile_dma_state.enabled);
-		current->thread.tile_dma_state.enabled = 1;
-		grant_dma_mpls();
-		return 1;
-	}
-
-	return 0;
-}
-
-#endif /* CHIP_HAS_TILE_DMA() */
-
-extern tile_bundle_bits bpt_code;
-
-asm(".pushsection .rodata.bpt_code,\"a\";"
-    ".align 8;"
-    "bpt_code: bpt;"
-    ".size bpt_code,.-bpt_code;"
-    ".popsection");
-
-static int special_ill(tile_bundle_bits bundle, int *sigp, int *codep)
-{
-	int sig, code, maxcode;
-
-	if (bundle == bpt_code) {
-		*sigp = SIGTRAP;
-		*codep = TRAP_BRKPT;
-		return 1;
-	}
-
-	/* If it's a "raise" bundle, then "ill" must be in pipe X1. */
-#ifdef __tilegx__
-	if ((bundle & TILEGX_BUNDLE_MODE_MASK) != 0)
-		return 0;
-	if (get_Opcode_X1(bundle) != RRR_0_OPCODE_X1)
-		return 0;
-	if (get_RRROpcodeExtension_X1(bundle) != UNARY_RRR_0_OPCODE_X1)
-		return 0;
-	if (get_UnaryOpcodeExtension_X1(bundle) != ILL_UNARY_OPCODE_X1)
-		return 0;
-#else
-	if (bundle & TILEPRO_BUNDLE_Y_ENCODING_MASK)
-		return 0;
-	if (get_Opcode_X1(bundle) != SHUN_0_OPCODE_X1)
-		return 0;
-	if (get_UnShOpcodeExtension_X1(bundle) != UN_0_SHUN_0_OPCODE_X1)
-		return 0;
-	if (get_UnOpcodeExtension_X1(bundle) != ILL_UN_0_SHUN_0_OPCODE_X1)
-		return 0;
-#endif
-
-	/* Check that the magic distinguishers are set to mean "raise". */
-	if (get_Dest_X1(bundle) != 29 || get_SrcA_X1(bundle) != 37)
-		return 0;
-
-	/* There must be an "addli zero, zero, VAL" in X0. */
-	if (get_Opcode_X0(bundle) != ADDLI_OPCODE_X0)
-		return 0;
-	if (get_Dest_X0(bundle) != TREG_ZERO)
-		return 0;
-	if (get_SrcA_X0(bundle) != TREG_ZERO)
-		return 0;
-
-	/*
-	 * Validate the proposed signal number and si_code value.
-	 * Note that we embed these in the static instruction itself
-	 * so that we perturb the register state as little as possible
-	 * at the time of the actual fault; it's unlikely you'd ever
-	 * need to dynamically choose which kind of fault to raise
-	 * from user space.
-	 */
-	sig = get_Imm16_X0(bundle) & 0x3f;
-	switch (sig) {
-	case SIGILL:
-		maxcode = NSIGILL;
-		break;
-	case SIGFPE:
-		maxcode = NSIGFPE;
-		break;
-	case SIGSEGV:
-		maxcode = NSIGSEGV;
-		break;
-	case SIGBUS:
-		maxcode = NSIGBUS;
-		break;
-	case SIGTRAP:
-		maxcode = NSIGTRAP;
-		break;
-	default:
-		return 0;
-	}
-	code = (get_Imm16_X0(bundle) >> 6) & 0xf;
-	if (code <= 0 || code > maxcode)
-		return 0;
-
-	/* Make it the requested signal. */
-	*sigp = sig;
-	*codep = code;
-	return 1;
-}
-
-static const char *const int_name[] = {
-	[INT_MEM_ERROR] = "Memory error",
-	[INT_ILL] = "Illegal instruction",
-	[INT_GPV] = "General protection violation",
-	[INT_UDN_ACCESS] = "UDN access",
-	[INT_IDN_ACCESS] = "IDN access",
-#if CHIP_HAS_SN()
-	[INT_SN_ACCESS] = "SN access",
-#endif
-	[INT_SWINT_3] = "Software interrupt 3",
-	[INT_SWINT_2] = "Software interrupt 2",
-	[INT_SWINT_0] = "Software interrupt 0",
-	[INT_UNALIGN_DATA] = "Unaligned data",
-	[INT_DOUBLE_FAULT] = "Double fault",
-#ifdef __tilegx__
-	[INT_ILL_TRANS] = "Illegal virtual address",
-#endif
-};
-
-static int do_bpt(struct pt_regs *regs)
-{
-	unsigned long bundle, bcode, bpt;
-
-	bundle = *(unsigned long *)instruction_pointer(regs);
-
-	/*
-	 * bpt shoule be { bpt; nop }, which is 0x286a44ae51485000ULL.
-	 * we encode the unused least significant bits for other purpose.
-	 */
-	bpt = bundle & ~((1ULL << 12) - 1);
-	if (bpt != TILE_BPT_BUNDLE)
-		return 0;
-
-	bcode = bundle & ((1ULL << 12) - 1);
-	/*
-	 * notify the kprobe handlers, if instruction is likely to
-	 * pertain to them.
-	 */
-	switch (bcode) {
-	/* breakpoint_insn */
-	case 0:
-		notify_die(DIE_BREAK, "debug", regs, bundle,
-			INT_ILL, SIGTRAP);
-		break;
-	/* compiled_bpt */
-	case DIE_COMPILED_BPT:
-		notify_die(DIE_COMPILED_BPT, "debug", regs, bundle,
-			INT_ILL, SIGTRAP);
-		break;
-	/* breakpoint2_insn */
-	case DIE_SSTEPBP:
-		notify_die(DIE_SSTEPBP, "single_step", regs, bundle,
-			INT_ILL, SIGTRAP);
-		break;
-	default:
-		return 0;
-	}
-
-	return 1;
-}
-
-void __kprobes do_trap(struct pt_regs *regs, int fault_num,
-		       unsigned long reason)
-{
-	siginfo_t info;
-	int signo, code;
-	unsigned long address = 0;
-	tile_bundle_bits instr;
-	int is_kernel = !user_mode(regs);
-
-	clear_siginfo(&info);
-
-	/* Handle breakpoints, etc. */
-	if (is_kernel && fault_num == INT_ILL && do_bpt(regs))
-		return;
-
-	/* Re-enable interrupts, if they were previously enabled. */
-	if (!(regs->flags & PT_FLAGS_DISABLE_IRQ))
-		local_irq_enable();
-
-	/*
-	 * If it hits in kernel mode and we can't fix it up, just exit the
-	 * current process and hope for the best.
-	 */
-	if (is_kernel) {
-		const char *name;
-		char buf[100];
-		if (fixup_exception(regs))  /* ILL_TRANS or UNALIGN_DATA */
-			return;
-		if (fault_num >= 0 &&
-		    fault_num < ARRAY_SIZE(int_name) &&
-		    int_name[fault_num] != NULL)
-			name = int_name[fault_num];
-		else
-			name = "Unknown interrupt";
-		if (fault_num == INT_GPV)
-			snprintf(buf, sizeof(buf), "; GPV_REASON %#lx", reason);
-#ifdef __tilegx__
-		else if (fault_num == INT_ILL_TRANS)
-			snprintf(buf, sizeof(buf), "; address %#lx", reason);
-#endif
-		else
-			buf[0] = '\0';
-		pr_alert("Kernel took bad trap %d (%s) at PC %#lx%s\n",
-			 fault_num, name, regs->pc, buf);
-		show_regs(regs);
-		do_exit(SIGKILL);  /* FIXME: implement i386 die() */
-	}
-
-	switch (fault_num) {
-	case INT_MEM_ERROR:
-		signo = SIGBUS;
-		code = BUS_OBJERR;
-		break;
-	case INT_ILL:
-		if (copy_from_user(&instr, (void __user *)regs->pc,
-				   sizeof(instr))) {
-			pr_err("Unreadable instruction for INT_ILL: %#lx\n",
-			       regs->pc);
-			do_exit(SIGKILL);
-		}
-		if (!special_ill(instr, &signo, &code)) {
-			signo = SIGILL;
-			code = ILL_ILLOPC;
-		}
-		address = regs->pc;
-		break;
-	case INT_GPV:
-#if CHIP_HAS_TILE_DMA()
-		if (retry_gpv(reason))
-			return;
-#endif
-		/*FALLTHROUGH*/
-	case INT_UDN_ACCESS:
-	case INT_IDN_ACCESS:
-#if CHIP_HAS_SN()
-	case INT_SN_ACCESS:
-#endif
-		signo = SIGILL;
-		code = ILL_PRVREG;
-		address = regs->pc;
-		break;
-	case INT_SWINT_3:
-	case INT_SWINT_2:
-	case INT_SWINT_0:
-		signo = SIGILL;
-		code = ILL_ILLTRP;
-		address = regs->pc;
-		break;
-	case INT_UNALIGN_DATA:
-#ifndef __tilegx__  /* Emulated support for single step debugging */
-		if (unaligned_fixup >= 0) {
-			struct single_step_state *state =
-				current_thread_info()->step_state;
-			if (!state ||
-			    (void __user *)(regs->pc) != state->buffer) {
-				single_step_once(regs);
-				return;
-			}
-		}
-#endif
-		signo = SIGBUS;
-		code = BUS_ADRALN;
-		address = 0;
-		break;
-	case INT_DOUBLE_FAULT:
-		/*
-		 * For double fault, "reason" is actually passed as
-		 * SYSTEM_SAVE_K_2, the hypervisor's double-fault info, so
-		 * we can provide the original fault number rather than
-		 * the uninteresting "INT_DOUBLE_FAULT" so the user can
-		 * learn what actually struck while PL0 ICS was set.
-		 */
-		fault_num = reason;
-		signo = SIGILL;
-		code = ILL_DBLFLT;
-		address = regs->pc;
-		break;
-#ifdef __tilegx__
-	case INT_ILL_TRANS: {
-		/* Avoid a hardware erratum with the return address stack. */
-		fill_ra_stack();
-
-		signo = SIGSEGV;
-		address = reason;
-		code = SEGV_MAPERR;
-		break;
-	}
-#endif
-	default:
-		panic("Unexpected do_trap interrupt number %d", fault_num);
-	}
-
-	info.si_signo = signo;
-	info.si_code = code;
-	info.si_addr = (void __user *)address;
-	if (signo == SIGILL)
-		info.si_trapno = fault_num;
-	if (signo != SIGTRAP)
-		trace_unhandled_signal("trap", regs, address, signo);
-	force_sig_info(signo, &info, current);
-}
-
-void do_nmi(struct pt_regs *regs, int fault_num, unsigned long reason)
-{
-	nmi_enter();
-	switch (reason) {
-#ifdef arch_trigger_cpumask_backtrace
-	case TILE_NMI_DUMP_STACK:
-		nmi_cpu_backtrace(regs);
-		break;
-#endif
-	default:
-		panic("Unexpected do_nmi type %ld", reason);
-	}
-	nmi_exit();
-}
-
-/* Deprecated function currently only used here. */
-extern void _dump_stack(int dummy, ulong pc, ulong lr, ulong sp, ulong r52);
-
-void kernel_double_fault(int dummy, ulong pc, ulong lr, ulong sp, ulong r52)
-{
-	_dump_stack(dummy, pc, lr, sp, r52);
-	pr_emerg("Double fault: exiting\n");
-	machine_halt();
-}