c6x: remove architecture

The c6x architecture was added to the kernel in 2011 at a time when
running Linux on DSPs was widely seen as the logical evolution.
It appears the trend has gone back to running Linux on Arm based SoCs
with DSP, using a better supported software ecosystem, and having better
real-time behavior for the DSP code. An example of this is TI's own
Keystone2 platform.

The upstream kernel port appears to no longer have any users. Mark
Salter remained avaialable to review patches, but mentioned that
he no longer has access to working hardware himself. Without any
users, it's best to just remove the code completely to reduce the
work for cross-architecture code changes.

Many thanks to Mark for maintaining the code for the past ten years.

Link: https://lore.kernel.org/lkml/41dc7795afda9f776d8cd0d3075f776cf586e97c.camel@redhat.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 0 insertions, 409 deletions

diff --git a/arch/c6x/kernel/traps.c b/arch/c6x/kernel/traps.c
deleted file mode 100644
index 2b9121c755be..000000000000
--- a/arch/c6x/kernel/traps.c
+++ /dev/null
@@ -1,409 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- *  Port on Texas Instruments TMS320C6x architecture
- *
- *  Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
- *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
- */
-#include <linux/module.h>
-#include <linux/ptrace.h>
-#include <linux/sched/debug.h>
-#include <linux/bug.h>
-
-#include <asm/soc.h>
-#include <asm/special_insns.h>
-#include <asm/traps.h>
-
-int (*c6x_nmi_handler)(struct pt_regs *regs);
-
-void __init trap_init(void)
-{
-	ack_exception(EXCEPT_TYPE_NXF);
-	ack_exception(EXCEPT_TYPE_EXC);
-	ack_exception(EXCEPT_TYPE_IXF);
-	ack_exception(EXCEPT_TYPE_SXF);
-	enable_exception();
-}
-
-void show_regs(struct pt_regs *regs)
-{
-	pr_err("\n");
-	show_regs_print_info(KERN_ERR);
-	pr_err("PC: %08lx SP: %08lx\n", regs->pc, regs->sp);
-	pr_err("Status: %08lx ORIG_A4: %08lx\n", regs->csr, regs->orig_a4);
-	pr_err("A0: %08lx  B0: %08lx\n", regs->a0, regs->b0);
-	pr_err("A1: %08lx  B1: %08lx\n", regs->a1, regs->b1);
-	pr_err("A2: %08lx  B2: %08lx\n", regs->a2, regs->b2);
-	pr_err("A3: %08lx  B3: %08lx\n", regs->a3, regs->b3);
-	pr_err("A4: %08lx  B4: %08lx\n", regs->a4, regs->b4);
-	pr_err("A5: %08lx  B5: %08lx\n", regs->a5, regs->b5);
-	pr_err("A6: %08lx  B6: %08lx\n", regs->a6, regs->b6);
-	pr_err("A7: %08lx  B7: %08lx\n", regs->a7, regs->b7);
-	pr_err("A8: %08lx  B8: %08lx\n", regs->a8, regs->b8);
-	pr_err("A9: %08lx  B9: %08lx\n", regs->a9, regs->b9);
-	pr_err("A10: %08lx  B10: %08lx\n", regs->a10, regs->b10);
-	pr_err("A11: %08lx  B11: %08lx\n", regs->a11, regs->b11);
-	pr_err("A12: %08lx  B12: %08lx\n", regs->a12, regs->b12);
-	pr_err("A13: %08lx  B13: %08lx\n", regs->a13, regs->b13);
-	pr_err("A14: %08lx  B14: %08lx\n", regs->a14, regs->dp);
-	pr_err("A15: %08lx  B15: %08lx\n", regs->a15, regs->sp);
-	pr_err("A16: %08lx  B16: %08lx\n", regs->a16, regs->b16);
-	pr_err("A17: %08lx  B17: %08lx\n", regs->a17, regs->b17);
-	pr_err("A18: %08lx  B18: %08lx\n", regs->a18, regs->b18);
-	pr_err("A19: %08lx  B19: %08lx\n", regs->a19, regs->b19);
-	pr_err("A20: %08lx  B20: %08lx\n", regs->a20, regs->b20);
-	pr_err("A21: %08lx  B21: %08lx\n", regs->a21, regs->b21);
-	pr_err("A22: %08lx  B22: %08lx\n", regs->a22, regs->b22);
-	pr_err("A23: %08lx  B23: %08lx\n", regs->a23, regs->b23);
-	pr_err("A24: %08lx  B24: %08lx\n", regs->a24, regs->b24);
-	pr_err("A25: %08lx  B25: %08lx\n", regs->a25, regs->b25);
-	pr_err("A26: %08lx  B26: %08lx\n", regs->a26, regs->b26);
-	pr_err("A27: %08lx  B27: %08lx\n", regs->a27, regs->b27);
-	pr_err("A28: %08lx  B28: %08lx\n", regs->a28, regs->b28);
-	pr_err("A29: %08lx  B29: %08lx\n", regs->a29, regs->b29);
-	pr_err("A30: %08lx  B30: %08lx\n", regs->a30, regs->b30);
-	pr_err("A31: %08lx  B31: %08lx\n", regs->a31, regs->b31);
-}
-
-void die(char *str, struct pt_regs *fp, int nr)
-{
-	console_verbose();
-	pr_err("%s: %08x\n", str, nr);
-	show_regs(fp);
-
-	pr_err("Process %s (pid: %d, stackpage=%08lx)\n",
-	       current->comm, current->pid, (PAGE_SIZE +
-					     (unsigned long) current));
-
-	dump_stack();
-	while (1)
-		;
-}
-
-static void die_if_kernel(char *str, struct pt_regs *fp, int nr)
-{
-	if (user_mode(fp))
-		return;
-
-	die(str, fp, nr);
-}
-
-
-/* Internal exceptions */
-static struct exception_info iexcept_table[10] = {
-	{ "Oops - instruction fetch", SIGBUS, BUS_ADRERR },
-	{ "Oops - fetch packet", SIGBUS, BUS_ADRERR },
-	{ "Oops - execute packet", SIGILL, ILL_ILLOPC },
-	{ "Oops - undefined instruction", SIGILL, ILL_ILLOPC },
-	{ "Oops - resource conflict", SIGILL, ILL_ILLOPC },
-	{ "Oops - resource access", SIGILL, ILL_PRVREG },
-	{ "Oops - privilege", SIGILL, ILL_PRVOPC },
-	{ "Oops - loops buffer", SIGILL, ILL_ILLOPC },
-	{ "Oops - software exception", SIGILL, ILL_ILLTRP },
-	{ "Oops - unknown exception", SIGILL, ILL_ILLOPC }
-};
-
-/* External exceptions */
-static struct exception_info eexcept_table[128] = {
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - external exception", SIGBUS, BUS_ADRERR },
-	{ "Oops - CPU memory protection fault", SIGSEGV, SEGV_ACCERR },
-	{ "Oops - CPU memory protection fault in L1P", SIGSEGV, SEGV_ACCERR },
-	{ "Oops - DMA memory protection fault in L1P", SIGSEGV, SEGV_ACCERR },
-	{ "Oops - CPU memory protection fault in L1D", SIGSEGV, SEGV_ACCERR },
-	{ "Oops - DMA memory protection fault in L1D", SIGSEGV, SEGV_ACCERR },
-	{ "Oops - CPU memory protection fault in L2", SIGSEGV, SEGV_ACCERR },
-	{ "Oops - DMA memory protection fault in L2", SIGSEGV, SEGV_ACCERR },
-	{ "Oops - EMC CPU memory protection fault", SIGSEGV, SEGV_ACCERR },
-	{ "Oops - EMC bus error", SIGBUS, BUS_ADRERR }
-};
-
-static void do_trap(struct exception_info *except_info, struct pt_regs *regs)
-{
-	unsigned long addr = instruction_pointer(regs);
-
-	if (except_info->code != TRAP_BRKPT)
-		pr_err("TRAP: %s PC[0x%lx] signo[%d] code[%d]\n",
-		       except_info->kernel_str, regs->pc,
-		       except_info->signo, except_info->code);
-
-	die_if_kernel(except_info->kernel_str, regs, addr);
-
-	force_sig_fault(except_info->signo, except_info->code,
-			(void __user *)addr);
-}
-
-/*
- * Process an internal exception (non maskable)
- */
-static int process_iexcept(struct pt_regs *regs)
-{
-	unsigned int iexcept_report = get_iexcept();
-	unsigned int iexcept_num;
-
-	ack_exception(EXCEPT_TYPE_IXF);
-
-	pr_err("IEXCEPT: PC[0x%lx]\n", regs->pc);
-
-	while (iexcept_report) {
-		iexcept_num = __ffs(iexcept_report);
-		iexcept_report &= ~(1 << iexcept_num);
-		set_iexcept(iexcept_report);
-		if (*(unsigned int *)regs->pc == BKPT_OPCODE) {
-			/* This is a breakpoint */
-			struct exception_info bkpt_exception = {
-				"Oops - undefined instruction",
-				  SIGTRAP, TRAP_BRKPT
-			};
-			do_trap(&bkpt_exception, regs);
-			iexcept_report &= ~(0xFF);
-			set_iexcept(iexcept_report);
-			continue;
-		}
-
-		do_trap(&iexcept_table[iexcept_num], regs);
-	}
-	return 0;
-}
-
-/*
- * Process an external exception (maskable)
- */
-static void process_eexcept(struct pt_regs *regs)
-{
-	int evt;
-
-	pr_err("EEXCEPT: PC[0x%lx]\n", regs->pc);
-
-	while ((evt = soc_get_exception()) >= 0)
-		do_trap(&eexcept_table[evt], regs);
-
-	ack_exception(EXCEPT_TYPE_EXC);
-}
-
-/*
- * Main exception processing
- */
-asmlinkage int process_exception(struct pt_regs *regs)
-{
-	unsigned int type;
-	unsigned int type_num;
-	unsigned int ie_num = 9; /* default is unknown exception */
-
-	while ((type = get_except_type()) != 0) {
-		type_num = fls(type) - 1;
-
-		switch (type_num) {
-		case EXCEPT_TYPE_NXF:
-			ack_exception(EXCEPT_TYPE_NXF);
-			if (c6x_nmi_handler)
-				(c6x_nmi_handler)(regs);
-			else
-				pr_alert("NMI interrupt!\n");
-			break;
-
-		case EXCEPT_TYPE_IXF:
-			if (process_iexcept(regs))
-				return 1;
-			break;
-
-		case EXCEPT_TYPE_EXC:
-			process_eexcept(regs);
-			break;
-
-		case EXCEPT_TYPE_SXF:
-			ie_num = 8;
-		default:
-			ack_exception(type_num);
-			do_trap(&iexcept_table[ie_num], regs);
-			break;
-		}
-	}
-	return 0;
-}
-
-static int kstack_depth_to_print = 48;
-
-static void show_trace(unsigned long *stack, unsigned long *endstack,
-		       const char *loglvl)
-{
-	unsigned long addr;
-	int i;
-
-	printk("%sCall trace:", loglvl);
-	i = 0;
-	while (stack + 1 <= endstack) {
-		addr = *stack++;
-		/*
-		 * If the address is either in the text segment of the
-		 * kernel, or in the region which contains vmalloc'ed
-		 * memory, it *may* be the address of a calling
-		 * routine; if so, print it so that someone tracing
-		 * down the cause of the crash will be able to figure
-		 * out the call path that was taken.
-		 */
-		if (__kernel_text_address(addr)) {
-#ifndef CONFIG_KALLSYMS
-			if (i % 5 == 0)
-				printk("%s\n	    ", loglvl);
-#endif
-			printk("%s [<%08lx>] %pS\n", loglvl, addr, (void *)addr);
-			i++;
-		}
-	}
-	printk("%s\n", loglvl);
-}
-
-void show_stack(struct task_struct *task, unsigned long *stack,
-		const char *loglvl)
-{
-	unsigned long *p, *endstack;
-	int i;
-
-	if (!stack) {
-		if (task && task != current)
-			/* We know this is a kernel stack,
-			   so this is the start/end */
-			stack = (unsigned long *)thread_saved_ksp(task);
-		else
-			stack = (unsigned long *)&stack;
-	}
-	endstack = (unsigned long *)(((unsigned long)stack + THREAD_SIZE - 1)
-				     & -THREAD_SIZE);
-
-	pr_debug("Stack from %08lx:", (unsigned long)stack);
-	for (i = 0, p = stack; i < kstack_depth_to_print; i++) {
-		if (p + 1 > endstack)
-			break;
-		if (i % 8 == 0)
-			pr_cont("\n	    ");
-		pr_cont(" %08lx", *p++);
-	}
-	pr_cont("\n");
-	show_trace(stack, endstack, loglvl);
-}
-
-int is_valid_bugaddr(unsigned long addr)
-{
-	return __kernel_text_address(addr);
-}