Initial import

1 files changed, 583 insertions, 0 deletions

diff --git a/arch/blackfin/kernel/traps.c b/arch/blackfin/kernel/traps.c
new file mode 100644
index 000000000..1ed85ddad
--- /dev/null
+++ b/arch/blackfin/kernel/traps.c
@@ -0,0 +1,583 @@
+/*
+ * Main exception handling logic.
+ *
+ * Copyright 2004-2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later
+ */
+
+#include <linux/bug.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <asm/traps.h>
+#include <asm/cplb.h>
+#include <asm/blackfin.h>
+#include <asm/irq_handler.h>
+#include <linux/irq.h>
+#include <asm/trace.h>
+#include <asm/fixed_code.h>
+#include <asm/pseudo_instructions.h>
+#include <asm/pda.h>
+#include <asm/asm-offsets.h>
+
+#ifdef CONFIG_KGDB
+# include <linux/kgdb.h>
+
+# define CHK_DEBUGGER_TRAP() \
+	do { \
+		kgdb_handle_exception(trapnr, sig, info.si_code, fp); \
+	} while (0)
+# define CHK_DEBUGGER_TRAP_MAYBE() \
+	do { \
+		if (kgdb_connected) \
+			CHK_DEBUGGER_TRAP(); \
+	} while (0)
+#else
+# define CHK_DEBUGGER_TRAP() do { } while (0)
+# define CHK_DEBUGGER_TRAP_MAYBE() do { } while (0)
+#endif
+
+
+#ifdef CONFIG_DEBUG_VERBOSE
+#define verbose_printk(fmt, arg...) \
+	printk(fmt, ##arg)
+#else
+#define verbose_printk(fmt, arg...) \
+	({ if (0) printk(fmt, ##arg); 0; })
+#endif
+
+#if defined(CONFIG_DEBUG_MMRS) || defined(CONFIG_DEBUG_MMRS_MODULE)
+u32 last_seqstat;
+#ifdef CONFIG_DEBUG_MMRS_MODULE
+EXPORT_SYMBOL(last_seqstat);
+#endif
+#endif
+
+/* Initiate the event table handler */
+void __init trap_init(void)
+{
+	CSYNC();
+	bfin_write_EVT3(trap);
+	CSYNC();
+}
+
+static int kernel_mode_regs(struct pt_regs *regs)
+{
+	return regs->ipend & 0xffc0;
+}
+
+asmlinkage notrace void trap_c(struct pt_regs *fp)
+{
+#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
+	int j;
+#endif
+#ifdef CONFIG_BFIN_PSEUDODBG_INSNS
+	int opcode;
+#endif
+	unsigned int cpu = raw_smp_processor_id();
+	const char *strerror = NULL;
+	int sig = 0;
+	siginfo_t info;
+	unsigned long trapnr = fp->seqstat & SEQSTAT_EXCAUSE;
+
+	trace_buffer_save(j);
+#if defined(CONFIG_DEBUG_MMRS) || defined(CONFIG_DEBUG_MMRS_MODULE)
+	last_seqstat = (u32)fp->seqstat;
+#endif
+
+	/* Important - be very careful dereferncing pointers - will lead to
+	 * double faults if the stack has become corrupt
+	 */
+
+	/* trap_c() will be called for exceptions. During exceptions
+	 * processing, the pc value should be set with retx value.
+	 * With this change we can cleanup some code in signal.c- TODO
+	 */
+	fp->orig_pc = fp->retx;
+	/* printk("exception: 0x%x, ipend=%x, reti=%x, retx=%x\n",
+		trapnr, fp->ipend, fp->pc, fp->retx); */
+
+	/* send the appropriate signal to the user program */
+	switch (trapnr) {
+
+	/* This table works in conjunction with the one in ./mach-common/entry.S
+	 * Some exceptions are handled there (in assembly, in exception space)
+	 * Some are handled here, (in C, in interrupt space)
+	 * Some, like CPLB, are handled in both, where the normal path is
+	 * handled in assembly/exception space, and the error path is handled
+	 * here
+	 */
+
+	/* 0x00 - Linux Syscall, getting here is an error */
+	/* 0x01 - userspace gdb breakpoint, handled here */
+	case VEC_EXCPT01:
+		info.si_code = TRAP_ILLTRAP;
+		sig = SIGTRAP;
+		CHK_DEBUGGER_TRAP_MAYBE();
+		/* Check if this is a breakpoint in kernel space */
+		if (kernel_mode_regs(fp))
+			goto traps_done;
+		else
+			break;
+	/* 0x03 - User Defined, userspace stack overflow */
+	case VEC_EXCPT03:
+		info.si_code = SEGV_STACKFLOW;
+		sig = SIGSEGV;
+		strerror = KERN_NOTICE EXC_0x03(KERN_NOTICE);
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+	/* 0x02 - KGDB initial connection and break signal trap */
+	case VEC_EXCPT02:
+#ifdef CONFIG_KGDB
+		info.si_code = TRAP_ILLTRAP;
+		sig = SIGTRAP;
+		CHK_DEBUGGER_TRAP();
+		goto traps_done;
+#endif
+	/* 0x04 - User Defined */
+	/* 0x05 - User Defined */
+	/* 0x06 - User Defined */
+	/* 0x07 - User Defined */
+	/* 0x08 - User Defined */
+	/* 0x09 - User Defined */
+	/* 0x0A - User Defined */
+	/* 0x0B - User Defined */
+	/* 0x0C - User Defined */
+	/* 0x0D - User Defined */
+	/* 0x0E - User Defined */
+	/* 0x0F - User Defined */
+	/* If we got here, it is most likely that someone was trying to use a
+	 * custom exception handler, and it is not actually installed properly
+	 */
+	case VEC_EXCPT04 ... VEC_EXCPT15:
+		info.si_code = ILL_ILLPARAOP;
+		sig = SIGILL;
+		strerror = KERN_NOTICE EXC_0x04(KERN_NOTICE);
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+	/* 0x10 HW Single step, handled here */
+	case VEC_STEP:
+		info.si_code = TRAP_STEP;
+		sig = SIGTRAP;
+		CHK_DEBUGGER_TRAP_MAYBE();
+		/* Check if this is a single step in kernel space */
+		if (kernel_mode_regs(fp))
+			goto traps_done;
+		else
+			break;
+	/* 0x11 - Trace Buffer Full, handled here */
+	case VEC_OVFLOW:
+		info.si_code = TRAP_TRACEFLOW;
+		sig = SIGTRAP;
+		strerror = KERN_NOTICE EXC_0x11(KERN_NOTICE);
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+	/* 0x12 - Reserved, Caught by default */
+	/* 0x13 - Reserved, Caught by default */
+	/* 0x14 - Reserved, Caught by default */
+	/* 0x15 - Reserved, Caught by default */
+	/* 0x16 - Reserved, Caught by default */
+	/* 0x17 - Reserved, Caught by default */
+	/* 0x18 - Reserved, Caught by default */
+	/* 0x19 - Reserved, Caught by default */
+	/* 0x1A - Reserved, Caught by default */
+	/* 0x1B - Reserved, Caught by default */
+	/* 0x1C - Reserved, Caught by default */
+	/* 0x1D - Reserved, Caught by default */
+	/* 0x1E - Reserved, Caught by default */
+	/* 0x1F - Reserved, Caught by default */
+	/* 0x20 - Reserved, Caught by default */
+	/* 0x21 - Undefined Instruction, handled here */
+	case VEC_UNDEF_I:
+#ifdef CONFIG_BUG
+		if (kernel_mode_regs(fp)) {
+			switch (report_bug(fp->pc, fp)) {
+			case BUG_TRAP_TYPE_NONE:
+				break;
+			case BUG_TRAP_TYPE_WARN:
+				dump_bfin_trace_buffer();
+				fp->pc += 2;
+				goto traps_done;
+			case BUG_TRAP_TYPE_BUG:
+				/* call to panic() will dump trace, and it is
+				 * off at this point, so it won't be clobbered
+				 */
+				panic("BUG()");
+			}
+		}
+#endif
+#ifdef CONFIG_BFIN_PSEUDODBG_INSNS
+		/*
+		 * Support for the fake instructions, if the instruction fails,
+		 * then just execute a illegal opcode failure (like normal).
+		 * Don't support these instructions inside the kernel
+		 */
+		if (!kernel_mode_regs(fp) && get_instruction(&opcode, (unsigned short *)fp->pc)) {
+			if (execute_pseudodbg_assert(fp, opcode))
+				goto traps_done;
+			if (execute_pseudodbg(fp, opcode))
+				goto traps_done;
+		}
+#endif
+		info.si_code = ILL_ILLOPC;
+		sig = SIGILL;
+		strerror = KERN_NOTICE EXC_0x21(KERN_NOTICE);
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+	/* 0x22 - Illegal Instruction Combination, handled here */
+	case VEC_ILGAL_I:
+		info.si_code = ILL_ILLPARAOP;
+		sig = SIGILL;
+		strerror = KERN_NOTICE EXC_0x22(KERN_NOTICE);
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+	/* 0x23 - Data CPLB protection violation, handled here */
+	case VEC_CPLB_VL:
+		info.si_code = ILL_CPLB_VI;
+		sig = SIGSEGV;
+		strerror = KERN_NOTICE EXC_0x23(KERN_NOTICE);
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+	/* 0x24 - Data access misaligned, handled here */
+	case VEC_MISALI_D:
+		info.si_code = BUS_ADRALN;
+		sig = SIGBUS;
+		strerror = KERN_NOTICE EXC_0x24(KERN_NOTICE);
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+	/* 0x25 - Unrecoverable Event, handled here */
+	case VEC_UNCOV:
+		info.si_code = ILL_ILLEXCPT;
+		sig = SIGILL;
+		strerror = KERN_NOTICE EXC_0x25(KERN_NOTICE);
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+	/* 0x26 - Data CPLB Miss, normal case is handled in _cplb_hdr,
+		error case is handled here */
+	case VEC_CPLB_M:
+		info.si_code = BUS_ADRALN;
+		sig = SIGBUS;
+		strerror = KERN_NOTICE EXC_0x26(KERN_NOTICE);
+		break;
+	/* 0x27 - Data CPLB Multiple Hits - Linux Trap Zero, handled here */
+	case VEC_CPLB_MHIT:
+		info.si_code = ILL_CPLB_MULHIT;
+		sig = SIGSEGV;
+#ifdef CONFIG_DEBUG_HUNT_FOR_ZERO
+		if (cpu_pda[cpu].dcplb_fault_addr < FIXED_CODE_START)
+			strerror = KERN_NOTICE "NULL pointer access\n";
+		else
+#endif
+			strerror = KERN_NOTICE EXC_0x27(KERN_NOTICE);
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+	/* 0x28 - Emulation Watchpoint, handled here */
+	case VEC_WATCH:
+		info.si_code = TRAP_WATCHPT;
+		sig = SIGTRAP;
+		pr_debug(EXC_0x28(KERN_DEBUG));
+		CHK_DEBUGGER_TRAP_MAYBE();
+		/* Check if this is a watchpoint in kernel space */
+		if (kernel_mode_regs(fp))
+			goto traps_done;
+		else
+			break;
+#ifdef CONFIG_BF535
+	/* 0x29 - Instruction fetch access error (535 only) */
+	case VEC_ISTRU_VL:      /* ADSP-BF535 only (MH) */
+		info.si_code = BUS_OPFETCH;
+		sig = SIGBUS;
+		strerror = KERN_NOTICE "BF535: VEC_ISTRU_VL\n";
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+#else
+	/* 0x29 - Reserved, Caught by default */
+#endif
+	/* 0x2A - Instruction fetch misaligned, handled here */
+	case VEC_MISALI_I:
+		info.si_code = BUS_ADRALN;
+		sig = SIGBUS;
+		strerror = KERN_NOTICE EXC_0x2A(KERN_NOTICE);
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+	/* 0x2B - Instruction CPLB protection violation, handled here */
+	case VEC_CPLB_I_VL:
+		info.si_code = ILL_CPLB_VI;
+		sig = SIGBUS;
+		strerror = KERN_NOTICE EXC_0x2B(KERN_NOTICE);
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+	/* 0x2C - Instruction CPLB miss, handled in _cplb_hdr */
+	case VEC_CPLB_I_M:
+		info.si_code = ILL_CPLB_MISS;
+		sig = SIGBUS;
+		strerror = KERN_NOTICE EXC_0x2C(KERN_NOTICE);
+		break;
+	/* 0x2D - Instruction CPLB Multiple Hits, handled here */
+	case VEC_CPLB_I_MHIT:
+		info.si_code = ILL_CPLB_MULHIT;
+		sig = SIGSEGV;
+#ifdef CONFIG_DEBUG_HUNT_FOR_ZERO
+		if (cpu_pda[cpu].icplb_fault_addr < FIXED_CODE_START)
+			strerror = KERN_NOTICE "Jump to NULL address\n";
+		else
+#endif
+			strerror = KERN_NOTICE EXC_0x2D(KERN_NOTICE);
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+	/* 0x2E - Illegal use of Supervisor Resource, handled here */
+	case VEC_ILL_RES:
+		info.si_code = ILL_PRVOPC;
+		sig = SIGILL;
+		strerror = KERN_NOTICE EXC_0x2E(KERN_NOTICE);
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+	/* 0x2F - Reserved, Caught by default */
+	/* 0x30 - Reserved, Caught by default */
+	/* 0x31 - Reserved, Caught by default */
+	/* 0x32 - Reserved, Caught by default */
+	/* 0x33 - Reserved, Caught by default */
+	/* 0x34 - Reserved, Caught by default */
+	/* 0x35 - Reserved, Caught by default */
+	/* 0x36 - Reserved, Caught by default */
+	/* 0x37 - Reserved, Caught by default */
+	/* 0x38 - Reserved, Caught by default */
+	/* 0x39 - Reserved, Caught by default */
+	/* 0x3A - Reserved, Caught by default */
+	/* 0x3B - Reserved, Caught by default */
+	/* 0x3C - Reserved, Caught by default */
+	/* 0x3D - Reserved, Caught by default */
+	/* 0x3E - Reserved, Caught by default */
+	/* 0x3F - Reserved, Caught by default */
+	case VEC_HWERR:
+		info.si_code = BUS_ADRALN;
+		sig = SIGBUS;
+		switch (fp->seqstat & SEQSTAT_HWERRCAUSE) {
+		/* System MMR Error */
+		case (SEQSTAT_HWERRCAUSE_SYSTEM_MMR):
+			info.si_code = BUS_ADRALN;
+			sig = SIGBUS;
+			strerror = KERN_NOTICE HWC_x2(KERN_NOTICE);
+			break;
+		/* External Memory Addressing Error */
+		case (SEQSTAT_HWERRCAUSE_EXTERN_ADDR):
+			if (ANOMALY_05000310) {
+				static unsigned long anomaly_rets;
+
+				if ((fp->pc >= (L1_CODE_START + L1_CODE_LENGTH - 512)) &&
+				    (fp->pc < (L1_CODE_START + L1_CODE_LENGTH))) {
+					/*
+					 * A false hardware error will happen while fetching at
+					 * the L1 instruction SRAM boundary.  Ignore it.
+					 */
+					anomaly_rets = fp->rets;
+					goto traps_done;
+				} else if (fp->rets == anomaly_rets) {
+					/*
+					 * While boundary code returns to a function, at the ret
+					 * point, a new false hardware error might occur too based
+					 * on tests.  Ignore it too.
+					 */
+					goto traps_done;
+				} else if ((fp->rets >= (L1_CODE_START + L1_CODE_LENGTH - 512)) &&
+				           (fp->rets < (L1_CODE_START + L1_CODE_LENGTH))) {
+					/*
+					 * If boundary code calls a function, at the entry point,
+					 * a new false hardware error maybe happen based on tests.
+					 * Ignore it too.
+					 */
+					goto traps_done;
+				} else
+					anomaly_rets = 0;
+			}
+
+			info.si_code = BUS_ADRERR;
+			sig = SIGBUS;
+			strerror = KERN_NOTICE HWC_x3(KERN_NOTICE);
+			break;
+		/* Performance Monitor Overflow */
+		case (SEQSTAT_HWERRCAUSE_PERF_FLOW):
+			strerror = KERN_NOTICE HWC_x12(KERN_NOTICE);
+			break;
+		/* RAISE 5 instruction */
+		case (SEQSTAT_HWERRCAUSE_RAISE_5):
+			printk(KERN_NOTICE HWC_x18(KERN_NOTICE));
+			break;
+		default:        /* Reserved */
+			printk(KERN_NOTICE HWC_default(KERN_NOTICE));
+			break;
+		}
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+	/*
+	 * We should be handling all known exception types above,
+	 * if we get here we hit a reserved one, so panic
+	 */
+	default:
+		info.si_code = ILL_ILLPARAOP;
+		sig = SIGILL;
+		verbose_printk(KERN_EMERG "Caught Unhandled Exception, code = %08lx\n",
+			(fp->seqstat & SEQSTAT_EXCAUSE));
+		CHK_DEBUGGER_TRAP_MAYBE();
+		break;
+	}
+
+	BUG_ON(sig == 0);
+
+	/* If the fault was caused by a kernel thread, or interrupt handler
+	 * we will kernel panic, so the system reboots.
+	 */
+	if (kernel_mode_regs(fp) || (current && !current->mm)) {
+		console_verbose();
+		oops_in_progress = 1;
+	}
+
+	if (sig != SIGTRAP) {
+		if (strerror)
+			verbose_printk(strerror);
+
+		dump_bfin_process(fp);
+		dump_bfin_mem(fp);
+		show_regs(fp);
+
+		/* Print out the trace buffer if it makes sense */
+#ifndef CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE
+		if (trapnr == VEC_CPLB_I_M || trapnr == VEC_CPLB_M)
+			verbose_printk(KERN_NOTICE "No trace since you do not have "
+			       "CONFIG_DEBUG_BFIN_NO_KERN_HWTRACE enabled\n\n");
+		else
+#endif
+			dump_bfin_trace_buffer();
+
+		if (oops_in_progress) {
+			/* Dump the current kernel stack */
+			verbose_printk(KERN_NOTICE "Kernel Stack\n");
+			show_stack(current, NULL);
+			print_modules();
+#ifndef CONFIG_ACCESS_CHECK
+			verbose_printk(KERN_EMERG "Please turn on "
+			       "CONFIG_ACCESS_CHECK\n");
+#endif
+			panic("Kernel exception");
+		} else {
+#ifdef CONFIG_DEBUG_VERBOSE
+			unsigned long *stack;
+			/* Dump the user space stack */
+			stack = (unsigned long *)rdusp();
+			verbose_printk(KERN_NOTICE "Userspace Stack\n");
+			show_stack(NULL, stack);
+#endif
+		}
+	}
+
+#ifdef CONFIG_IPIPE
+	if (!ipipe_trap_notify(fp->seqstat & 0x3f, fp))
+#endif
+	{
+		info.si_signo = sig;
+		info.si_errno = 0;
+		switch (trapnr) {
+		case VEC_CPLB_VL:
+		case VEC_MISALI_D:
+		case VEC_CPLB_M:
+		case VEC_CPLB_MHIT:
+			info.si_addr = (void __user *)cpu_pda[cpu].dcplb_fault_addr;
+			break;
+		default:
+			info.si_addr = (void __user *)fp->pc;
+			break;
+		}
+		force_sig_info(sig, &info, current);
+	}
+
+	if ((ANOMALY_05000461 && trapnr == VEC_HWERR && !access_ok(VERIFY_READ, fp->pc, 8)) ||
+	    (ANOMALY_05000281 && trapnr == VEC_HWERR) ||
+	    (ANOMALY_05000189 && (trapnr == VEC_CPLB_I_VL || trapnr == VEC_CPLB_VL)))
+		fp->pc = SAFE_USER_INSTRUCTION;
+
+ traps_done:
+	trace_buffer_restore(j);
+}
+
+asmlinkage void double_fault_c(struct pt_regs *fp)
+{
+#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
+	int j;
+	trace_buffer_save(j);
+#endif
+
+	console_verbose();
+	oops_in_progress = 1;
+#ifdef CONFIG_DEBUG_VERBOSE
+	printk(KERN_EMERG "Double Fault\n");
+#ifdef CONFIG_DEBUG_DOUBLEFAULT_PRINT
+	if (((long)fp->seqstat &  SEQSTAT_EXCAUSE) == VEC_UNCOV) {
+		unsigned int cpu = raw_smp_processor_id();
+		char buf[150];
+		decode_address(buf, cpu_pda[cpu].retx_doublefault);
+		printk(KERN_EMERG "While handling exception (EXCAUSE = 0x%x) at %s:\n",
+			(unsigned int)cpu_pda[cpu].seqstat_doublefault & SEQSTAT_EXCAUSE, buf);
+		decode_address(buf, cpu_pda[cpu].dcplb_doublefault_addr);
+		printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %s\n", buf);
+		decode_address(buf, cpu_pda[cpu].icplb_doublefault_addr);
+		printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %s\n", buf);
+
+		decode_address(buf, fp->retx);
+		printk(KERN_NOTICE "The instruction at %s caused a double exception\n", buf);
+	} else
+#endif
+	{
+		dump_bfin_process(fp);
+		dump_bfin_mem(fp);
+		show_regs(fp);
+		dump_bfin_trace_buffer();
+	}
+#endif
+	panic("Double Fault - unrecoverable event");
+
+}
+
+
+void panic_cplb_error(int cplb_panic, struct pt_regs *fp)
+{
+	switch (cplb_panic) {
+	case CPLB_NO_UNLOCKED:
+		printk(KERN_EMERG "All CPLBs are locked\n");
+		break;
+	case CPLB_PROT_VIOL:
+		return;
+	case CPLB_NO_ADDR_MATCH:
+		return;
+	case CPLB_UNKNOWN_ERR:
+		printk(KERN_EMERG "Unknown CPLB Exception\n");
+		break;
+	}
+
+	oops_in_progress = 1;
+
+	dump_bfin_process(fp);
+	dump_bfin_mem(fp);
+	show_regs(fp);
+	dump_stack();
+	panic("Unrecoverable event");
+}
+
+#ifdef CONFIG_BUG
+int is_valid_bugaddr(unsigned long addr)
+{
+	unsigned int opcode;
+
+	if (!get_instruction(&opcode, (unsigned short *)addr))
+		return 0;
+
+	return opcode == BFIN_BUG_OPCODE;
+}
+#endif
+
+/* stub this out */
+#ifndef CONFIG_DEBUG_VERBOSE
+void show_regs(struct pt_regs *fp)
+{
+
+}
+#endif