C6X: build infrastructure

Original port to early 2.6 kernel using TI COFF toolchain.
Brought up to date by Mark Salter <msalter@redhat.com>

Signed-off-by: Aurelien Jacquiot <a-jacquiot@ti.com>
Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/arch/c6x/kernel/traps.c b/arch/c6x/kernel/traps.c
new file mode 100644
index 0000000..f50e3ed
--- /dev/null
+++ b/arch/c6x/kernel/traps.c
@@ -0,0 +1,423 @@
+/*
+ *  Port on Texas Instruments TMS320C6x architecture
+ *
+ *  Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
+ *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2 as
+ *  published by the Free Software Foundation.
+ */
+#include <linux/module.h>
+#include <linux/ptrace.h>
+#include <linux/kallsyms.h>
+#include <linux/bug.h>
+
+#include <asm/soc.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");
+	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 dump_stack(void)
+{
+	unsigned long stack;
+
+	show_stack(current, &stack);
+}
+EXPORT_SYMBOL(dump_stack);
+
+
+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);
+	siginfo_t info;
+
+	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);
+
+	info.si_signo = except_info->signo;
+	info.si_errno = 0;
+	info.si_code  = except_info->code;
+	info.si_addr  = (void __user *)addr;
+
+	force_sig_info(except_info->signo, &info, current);
+}
+
+/*
+ * 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)
+{
+	unsigned long addr;
+	int i;
+
+	pr_debug("Call trace:");
+	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)
+				pr_debug("\n	    ");
+#endif
+			pr_debug(" [<%08lx>]", addr);
+			print_symbol(" %s\n", addr);
+			i++;
+		}
+	}
+	pr_debug("\n");
+}
+
+void show_stack(struct task_struct *task, unsigned long *stack)
+{
+	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);
+}
+
+int is_valid_bugaddr(unsigned long addr)
+{
+	return __kernel_text_address(addr);
+}