sh: Move in the SH-5 traps.c impl.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

4 files changed, 983 insertions, 2 deletions

diff --git a/arch/sh/kernel/Makefile_32 b/arch/sh/kernel/Makefile_32
index bad6bf5ac478..29b44eb3b934 100644
--- a/arch/sh/kernel/Makefile_32
+++ b/arch/sh/kernel/Makefile_32
@@ -6,7 +6,7 @@ extra-y	:= head.o init_task.o vmlinux.lds
 
 obj-y	:= debugtraps.o io.o io_generic.o irq.o machvec.o process_32.o \
 	   ptrace_32.o semaphore.o setup.o signal_32.o sys_sh.o syscalls.o \
-	   time.o topology.o traps.o
+	   time.o topology.o traps_32.o
 
 obj-y				+= cpu/ timers/
 obj-$(CONFIG_VSYSCALL)		+= vsyscall/
diff --git a/arch/sh/kernel/Makefile_64 b/arch/sh/kernel/Makefile_64
index 1f27d5fd99a8..fb87d642d1c1 100644
--- a/arch/sh/kernel/Makefile_64
+++ b/arch/sh/kernel/Makefile_64
@@ -2,7 +2,7 @@ extra-y	:= head.o init_task.o vmlinux.lds
 
 obj-y	:= debugtraps.o io.o io_generic.o irq.o machvec.o process_64.o \
 	   ptrace_64.o semaphore.o setup.o signal_64.o sys_sh64.o syscalls.o \
-	   time.o topology.o traps.o
+	   time.o topology.o traps_64.o
 
 obj-y				+= cpu/ timers/
 obj-$(CONFIG_VSYSCALL)		+= vsyscall/
diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps_32.c
index cf99111cb33f..cf99111cb33f 100644
--- a/arch/sh/kernel/traps.c
+++ b/arch/sh/kernel/traps_32.c
diff --git a/arch/sh/kernel/traps_64.c b/arch/sh/kernel/traps_64.c
new file mode 100644
index 000000000000..742ce18b6820
--- /dev/null
+++ b/arch/sh/kernel/traps_64.c
@@ -0,0 +1,981 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * arch/sh64/kernel/traps.c
+ *
+ * Copyright (C) 2000, 2001  Paolo Alberelli
+ * Copyright (C) 2003, 2004  Paul Mundt
+ * Copyright (C) 2003, 2004  Richard Curnow
+ *
+ */
+
+/*
+ * 'Traps.c' handles hardware traps and faults after we have saved some
+ * state in 'entry.S'.
+ */
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/kallsyms.h>
+#include <linux/interrupt.h>
+#include <linux/sysctl.h>
+#include <linux/module.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/atomic.h>
+#include <asm/processor.h>
+#include <asm/pgtable.h>
+
+#undef DEBUG_EXCEPTION
+#ifdef DEBUG_EXCEPTION
+/* implemented in ../lib/dbg.c */
+extern void show_excp_regs(char *fname, int trapnr, int signr,
+			   struct pt_regs *regs);
+#else
+#define show_excp_regs(a, b, c, d)
+#endif
+
+static void do_unhandled_exception(int trapnr, int signr, char *str, char *fn_name,
+		unsigned long error_code, struct pt_regs *regs, struct task_struct *tsk);
+
+#define DO_ERROR(trapnr, signr, str, name, tsk) \
+asmlinkage void do_##name(unsigned long error_code, struct pt_regs *regs) \
+{ \
+	do_unhandled_exception(trapnr, signr, str, __stringify(name), error_code, regs, current); \
+}
+
+spinlock_t die_lock;
+
+void die(const char * str, struct pt_regs * regs, long err)
+{
+	console_verbose();
+	spin_lock_irq(&die_lock);
+	printk("%s: %lx\n", str, (err & 0xffffff));
+	show_regs(regs);
+	spin_unlock_irq(&die_lock);
+	do_exit(SIGSEGV);
+}
+
+static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
+{
+	if (!user_mode(regs))
+		die(str, regs, err);
+}
+
+static void die_if_no_fixup(const char * str, struct pt_regs * regs, long err)
+{
+	if (!user_mode(regs)) {
+		const struct exception_table_entry *fixup;
+		fixup = search_exception_tables(regs->pc);
+		if (fixup) {
+			regs->pc = fixup->fixup;
+			return;
+		}
+		die(str, regs, err);
+	}
+}
+
+DO_ERROR(13, SIGILL,  "illegal slot instruction", illegal_slot_inst, current)
+DO_ERROR(87, SIGSEGV, "address error (exec)", address_error_exec, current)
+
+
+/* Implement misaligned load/store handling for kernel (and optionally for user
+   mode too).  Limitation : only SHmedia mode code is handled - there is no
+   handling at all for misaligned accesses occurring in SHcompact code yet. */
+
+static int misaligned_fixup(struct pt_regs *regs);
+
+asmlinkage void do_address_error_load(unsigned long error_code, struct pt_regs *regs)
+{
+	if (misaligned_fixup(regs) < 0) {
+		do_unhandled_exception(7, SIGSEGV, "address error(load)",
+				"do_address_error_load",
+				error_code, regs, current);
+	}
+	return;
+}
+
+asmlinkage void do_address_error_store(unsigned long error_code, struct pt_regs *regs)
+{
+	if (misaligned_fixup(regs) < 0) {
+		do_unhandled_exception(8, SIGSEGV, "address error(store)",
+				"do_address_error_store",
+				error_code, regs, current);
+	}
+	return;
+}
+
+#if defined(CONFIG_SH64_ID2815_WORKAROUND)
+
+#define OPCODE_INVALID      0
+#define OPCODE_USER_VALID   1
+#define OPCODE_PRIV_VALID   2
+
+/* getcon/putcon - requires checking which control register is referenced. */
+#define OPCODE_CTRL_REG     3
+
+/* Table of valid opcodes for SHmedia mode.
+   Form a 10-bit value by concatenating the major/minor opcodes i.e.
+   opcode[31:26,20:16].  The 6 MSBs of this value index into the following
+   array.  The 4 LSBs select the bit-pair in the entry (bits 1:0 correspond to
+   LSBs==4'b0000 etc). */
+static unsigned long shmedia_opcode_table[64] = {
+	0x55554044,0x54445055,0x15141514,0x14541414,0x00000000,0x10001000,0x01110055,0x04050015,
+	0x00000444,0xc0000000,0x44545515,0x40405555,0x55550015,0x10005555,0x55555505,0x04050000,
+	0x00000555,0x00000404,0x00040445,0x15151414,0x00000000,0x00000000,0x00000000,0x00000000,
+	0x00000055,0x40404444,0x00000404,0xc0009495,0x00000000,0x00000000,0x00000000,0x00000000,
+	0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
+	0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
+	0x80005050,0x04005055,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,0x55555555,
+	0x81055554,0x00000404,0x55555555,0x55555555,0x00000000,0x00000000,0x00000000,0x00000000
+};
+
+void do_reserved_inst(unsigned long error_code, struct pt_regs *regs)
+{
+	/* Workaround SH5-101 cut2 silicon defect #2815 :
+	   in some situations, inter-mode branches from SHcompact -> SHmedia
+	   which should take ITLBMISS or EXECPROT exceptions at the target
+	   falsely take RESINST at the target instead. */
+
+	unsigned long opcode = 0x6ff4fff0; /* guaranteed reserved opcode */
+	unsigned long pc, aligned_pc;
+	int get_user_error;
+	int trapnr = 12;
+	int signr = SIGILL;
+	char *exception_name = "reserved_instruction";
+
+	pc = regs->pc;
+	if ((pc & 3) == 1) {
+		/* SHmedia : check for defect.  This requires executable vmas
+		   to be readable too. */
+		aligned_pc = pc & ~3;
+		if (!access_ok(VERIFY_READ, aligned_pc, sizeof(unsigned long))) {
+			get_user_error = -EFAULT;
+		} else {
+			get_user_error = __get_user(opcode, (unsigned long *)aligned_pc);
+		}
+		if (get_user_error >= 0) {
+			unsigned long index, shift;
+			unsigned long major, minor, combined;
+			unsigned long reserved_field;
+			reserved_field = opcode & 0xf; /* These bits are currently reserved as zero in all valid opcodes */
+			major = (opcode >> 26) & 0x3f;
+			minor = (opcode >> 16) & 0xf;
+			combined = (major << 4) | minor;
+			index = major;
+			shift = minor << 1;
+			if (reserved_field == 0) {
+				int opcode_state = (shmedia_opcode_table[index] >> shift) & 0x3;
+				switch (opcode_state) {
+					case OPCODE_INVALID:
+						/* Trap. */
+						break;
+					case OPCODE_USER_VALID:
+						/* Restart the instruction : the branch to the instruction will now be from an RTE
+						   not from SHcompact so the silicon defect won't be triggered. */
+						return;
+					case OPCODE_PRIV_VALID:
+						if (!user_mode(regs)) {
+							/* Should only ever get here if a module has
+							   SHcompact code inside it.  If so, the same fix up is needed. */
+							return; /* same reason */
+						}
+						/* Otherwise, user mode trying to execute a privileged instruction -
+						   fall through to trap. */
+						break;
+					case OPCODE_CTRL_REG:
+						/* If in privileged mode, return as above. */
+						if (!user_mode(regs)) return;
+						/* In user mode ... */
+						if (combined == 0x9f) { /* GETCON */
+							unsigned long regno = (opcode >> 20) & 0x3f;
+							if (regno >= 62) {
+								return;
+							}
+							/* Otherwise, reserved or privileged control register, => trap */
+						} else if (combined == 0x1bf) { /* PUTCON */
+							unsigned long regno = (opcode >> 4) & 0x3f;
+							if (regno >= 62) {
+								return;
+							}
+							/* Otherwise, reserved or privileged control register, => trap */
+						} else {
+							/* Trap */
+						}
+						break;
+					default:
+						/* Fall through to trap. */
+						break;
+				}
+			}
+			/* fall through to normal resinst processing */
+		} else {
+			/* Error trying to read opcode.  This typically means a
+			   real fault, not a RESINST any more.  So change the
+			   codes. */
+			trapnr = 87;
+			exception_name = "address error (exec)";
+			signr = SIGSEGV;
+		}
+	}
+
+	do_unhandled_exception(trapnr, signr, exception_name, "do_reserved_inst", error_code, regs, current);
+}
+
+#else /* CONFIG_SH64_ID2815_WORKAROUND */
+
+/* If the workaround isn't needed, this is just a straightforward reserved
+   instruction */
+DO_ERROR(12, SIGILL,  "reserved instruction", reserved_inst, current)
+
+#endif /* CONFIG_SH64_ID2815_WORKAROUND */
+
+/* Called with interrupts disabled */
+asmlinkage void do_exception_error(unsigned long ex, struct pt_regs *regs)
+{
+	show_excp_regs(__FUNCTION__, -1, -1, regs);
+	die_if_kernel("exception", regs, ex);
+}
+
+int do_unknown_trapa(unsigned long scId, struct pt_regs *regs)
+{
+	/* Syscall debug */
+        printk("System call ID error: [0x1#args:8 #syscall:16  0x%lx]\n", scId);
+
+	die_if_kernel("unknown trapa", regs, scId);
+
+	return -ENOSYS;
+}
+
+void show_stack(struct task_struct *tsk, unsigned long *sp)
+{
+#ifdef CONFIG_KALLSYMS
+	extern void sh64_unwind(struct pt_regs *regs);
+	struct pt_regs *regs;
+
+	regs = tsk ? tsk->thread.kregs : NULL;
+
+	sh64_unwind(regs);
+#else
+	printk(KERN_ERR "Can't backtrace on sh64 without CONFIG_KALLSYMS\n");
+#endif
+}
+
+void show_task(unsigned long *sp)
+{
+	show_stack(NULL, sp);
+}
+
+void dump_stack(void)
+{
+	show_task(NULL);
+}
+/* Needed by any user of WARN_ON in view of the defn in include/asm-sh/bug.h */
+EXPORT_SYMBOL(dump_stack);
+
+static void do_unhandled_exception(int trapnr, int signr, char *str, char *fn_name,
+		unsigned long error_code, struct pt_regs *regs, struct task_struct *tsk)
+{
+	show_excp_regs(fn_name, trapnr, signr, regs);
+	tsk->thread.error_code = error_code;
+	tsk->thread.trap_no = trapnr;
+
+	if (user_mode(regs))
+		force_sig(signr, tsk);
+
+	die_if_no_fixup(str, regs, error_code);
+}
+
+static int read_opcode(unsigned long long pc, unsigned long *result_opcode, int from_user_mode)
+{
+	int get_user_error;
+	unsigned long aligned_pc;
+	unsigned long opcode;
+
+	if ((pc & 3) == 1) {
+		/* SHmedia */
+		aligned_pc = pc & ~3;
+		if (from_user_mode) {
+			if (!access_ok(VERIFY_READ, aligned_pc, sizeof(unsigned long))) {
+				get_user_error = -EFAULT;
+			} else {
+				get_user_error = __get_user(opcode, (unsigned long *)aligned_pc);
+				*result_opcode = opcode;
+			}
+			return get_user_error;
+		} else {
+			/* If the fault was in the kernel, we can either read
+			 * this directly, or if not, we fault.
+			*/
+			*result_opcode = *(unsigned long *) aligned_pc;
+			return 0;
+		}
+	} else if ((pc & 1) == 0) {
+		/* SHcompact */
+		/* TODO : provide handling for this.  We don't really support
+		   user-mode SHcompact yet, and for a kernel fault, this would
+		   have to come from a module built for SHcompact.  */
+		return -EFAULT;
+	} else {
+		/* misaligned */
+		return -EFAULT;
+	}
+}
+
+static int address_is_sign_extended(__u64 a)
+{
+	__u64 b;
+#if (NEFF == 32)
+	b = (__u64)(__s64)(__s32)(a & 0xffffffffUL);
+	return (b == a) ? 1 : 0;
+#else
+#error "Sign extend check only works for NEFF==32"
+#endif
+}
+
+static int generate_and_check_address(struct pt_regs *regs,
+				      __u32 opcode,
+				      int displacement_not_indexed,
+				      int width_shift,
+				      __u64 *address)
+{
+	/* return -1 for fault, 0 for OK */
+
+	__u64 base_address, addr;
+	int basereg;
+
+	basereg = (opcode >> 20) & 0x3f;
+	base_address = regs->regs[basereg];
+	if (displacement_not_indexed) {
+		__s64 displacement;
+		displacement = (opcode >> 10) & 0x3ff;
+		displacement = ((displacement << 54) >> 54); /* sign extend */
+		addr = (__u64)((__s64)base_address + (displacement << width_shift));
+	} else {
+		__u64 offset;
+		int offsetreg;
+		offsetreg = (opcode >> 10) & 0x3f;
+		offset = regs->regs[offsetreg];
+		addr = base_address + offset;
+	}
+
+	/* Check sign extended */
+	if (!address_is_sign_extended(addr)) {
+		return -1;
+	}
+
+#if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
+	/* Check accessible.  For misaligned access in the kernel, assume the
+	   address is always accessible (and if not, just fault when the
+	   load/store gets done.) */
+	if (user_mode(regs)) {
+		if (addr >= TASK_SIZE) {
+			return -1;
+		}
+		/* Do access_ok check later - it depends on whether it's a load or a store. */
+	}
+#endif
+
+	*address = addr;
+	return 0;
+}
+
+/* Default value as for sh */
+#if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
+static int user_mode_unaligned_fixup_count = 10;
+static int user_mode_unaligned_fixup_enable = 1;
+#endif
+
+static int kernel_mode_unaligned_fixup_count = 32;
+
+static void misaligned_kernel_word_load(__u64 address, int do_sign_extend, __u64 *result)
+{
+	unsigned short x;
+	unsigned char *p, *q;
+	p = (unsigned char *) (int) address;
+	q = (unsigned char *) &x;
+	q[0] = p[0];
+	q[1] = p[1];
+
+	if (do_sign_extend) {
+		*result = (__u64)(__s64) *(short *) &x;
+	} else {
+		*result = (__u64) x;
+	}
+}
+
+static void misaligned_kernel_word_store(__u64 address, __u64 value)
+{
+	unsigned short x;
+	unsigned char *p, *q;
+	p = (unsigned char *) (int) address;
+	q = (unsigned char *) &x;
+
+	x = (__u16) value;
+	p[0] = q[0];
+	p[1] = q[1];
+}
+
+static int misaligned_load(struct pt_regs *regs,
+			   __u32 opcode,
+			   int displacement_not_indexed,
+			   int width_shift,
+			   int do_sign_extend)
+{
+	/* Return -1 for a fault, 0 for OK */
+	int error;
+	int destreg;
+	__u64 address;
+
+	error = generate_and_check_address(regs, opcode,
+			displacement_not_indexed, width_shift, &address);
+	if (error < 0) {
+		return error;
+	}
+
+	destreg = (opcode >> 4) & 0x3f;
+#if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
+	if (user_mode(regs)) {
+		__u64 buffer;
+
+		if (!access_ok(VERIFY_READ, (unsigned long) address, 1UL<<width_shift)) {
+			return -1;
+		}
+
+		if (__copy_user(&buffer, (const void *)(int)address, (1 << width_shift)) > 0) {
+			return -1; /* fault */
+		}
+		switch (width_shift) {
+		case 1:
+			if (do_sign_extend) {
+				regs->regs[destreg] = (__u64)(__s64) *(__s16 *) &buffer;
+			} else {
+				regs->regs[destreg] = (__u64) *(__u16 *) &buffer;
+			}
+			break;
+		case 2:
+			regs->regs[destreg] = (__u64)(__s64) *(__s32 *) &buffer;
+			break;
+		case 3:
+			regs->regs[destreg] = buffer;
+			break;
+		default:
+			printk("Unexpected width_shift %d in misaligned_load, PC=%08lx\n",
+				width_shift, (unsigned long) regs->pc);
+			break;
+		}
+	} else
+#endif
+	{
+		/* kernel mode - we can take short cuts since if we fault, it's a genuine bug */
+		__u64 lo, hi;
+
+		switch (width_shift) {
+		case 1:
+			misaligned_kernel_word_load(address, do_sign_extend, &regs->regs[destreg]);
+			break;
+		case 2:
+			asm ("ldlo.l %1, 0, %0" : "=r" (lo) : "r" (address));
+			asm ("ldhi.l %1, 3, %0" : "=r" (hi) : "r" (address));
+			regs->regs[destreg] = lo | hi;
+			break;
+		case 3:
+			asm ("ldlo.q %1, 0, %0" : "=r" (lo) : "r" (address));
+			asm ("ldhi.q %1, 7, %0" : "=r" (hi) : "r" (address));
+			regs->regs[destreg] = lo | hi;
+			break;
+
+		default:
+			printk("Unexpected width_shift %d in misaligned_load, PC=%08lx\n",
+				width_shift, (unsigned long) regs->pc);
+			break;
+		}
+	}
+
+	return 0;
+
+}
+
+static int misaligned_store(struct pt_regs *regs,
+			    __u32 opcode,
+			    int displacement_not_indexed,
+			    int width_shift)
+{
+	/* Return -1 for a fault, 0 for OK */
+	int error;
+	int srcreg;
+	__u64 address;
+
+	error = generate_and_check_address(regs, opcode,
+			displacement_not_indexed, width_shift, &address);
+	if (error < 0) {
+		return error;
+	}
+
+	srcreg = (opcode >> 4) & 0x3f;
+#if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
+	if (user_mode(regs)) {
+		__u64 buffer;
+
+		if (!access_ok(VERIFY_WRITE, (unsigned long) address, 1UL<<width_shift)) {
+			return -1;
+		}
+
+		switch (width_shift) {
+		case 1:
+			*(__u16 *) &buffer = (__u16) regs->regs[srcreg];
+			break;
+		case 2:
+			*(__u32 *) &buffer = (__u32) regs->regs[srcreg];
+			break;
+		case 3:
+			buffer = regs->regs[srcreg];
+			break;
+		default:
+			printk("Unexpected width_shift %d in misaligned_store, PC=%08lx\n",
+				width_shift, (unsigned long) regs->pc);
+			break;
+		}
+
+		if (__copy_user((void *)(int)address, &buffer, (1 << width_shift)) > 0) {
+			return -1; /* fault */
+		}
+	} else
+#endif
+	{
+		/* kernel mode - we can take short cuts since if we fault, it's a genuine bug */
+		__u64 val = regs->regs[srcreg];
+
+		switch (width_shift) {
+		case 1:
+			misaligned_kernel_word_store(address, val);
+			break;
+		case 2:
+			asm ("stlo.l %1, 0, %0" : : "r" (val), "r" (address));
+			asm ("sthi.l %1, 3, %0" : : "r" (val), "r" (address));
+			break;
+		case 3:
+			asm ("stlo.q %1, 0, %0" : : "r" (val), "r" (address));
+			asm ("sthi.q %1, 7, %0" : : "r" (val), "r" (address));
+			break;
+
+		default:
+			printk("Unexpected width_shift %d in misaligned_store, PC=%08lx\n",
+				width_shift, (unsigned long) regs->pc);
+			break;
+		}
+	}
+
+	return 0;
+
+}
+
+#if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
+/* Never need to fix up misaligned FPU accesses within the kernel since that's a real
+   error. */
+static int misaligned_fpu_load(struct pt_regs *regs,
+			   __u32 opcode,
+			   int displacement_not_indexed,
+			   int width_shift,
+			   int do_paired_load)
+{
+	/* Return -1 for a fault, 0 for OK */
+	int error;
+	int destreg;
+	__u64 address;
+
+	error = generate_and_check_address(regs, opcode,
+			displacement_not_indexed, width_shift, &address);
+	if (error < 0) {
+		return error;
+	}
+
+	destreg = (opcode >> 4) & 0x3f;
+	if (user_mode(regs)) {
+		__u64 buffer;
+		__u32 buflo, bufhi;
+
+		if (!access_ok(VERIFY_READ, (unsigned long) address, 1UL<<width_shift)) {
+			return -1;
+		}
+
+		if (__copy_user(&buffer, (const void *)(int)address, (1 << width_shift)) > 0) {
+			return -1; /* fault */
+		}
+		/* 'current' may be the current owner of the FPU state, so
+		   context switch the registers into memory so they can be
+		   indexed by register number. */
+		if (last_task_used_math == current) {
+			grab_fpu();
+			fpsave(&current->thread.fpu.hard);
+			release_fpu();
+			last_task_used_math = NULL;
+			regs->sr |= SR_FD;
+		}
+
+		buflo = *(__u32*) &buffer;
+		bufhi = *(1 + (__u32*) &buffer);
+
+		switch (width_shift) {
+		case 2:
+			current->thread.fpu.hard.fp_regs[destreg] = buflo;
+			break;
+		case 3:
+			if (do_paired_load) {
+				current->thread.fpu.hard.fp_regs[destreg] = buflo;
+				current->thread.fpu.hard.fp_regs[destreg+1] = bufhi;
+			} else {
+#if defined(CONFIG_LITTLE_ENDIAN)
+				current->thread.fpu.hard.fp_regs[destreg] = bufhi;
+				current->thread.fpu.hard.fp_regs[destreg+1] = buflo;
+#else
+				current->thread.fpu.hard.fp_regs[destreg] = buflo;
+				current->thread.fpu.hard.fp_regs[destreg+1] = bufhi;
+#endif
+			}
+			break;
+		default:
+			printk("Unexpected width_shift %d in misaligned_fpu_load, PC=%08lx\n",
+				width_shift, (unsigned long) regs->pc);
+			break;
+		}
+		return 0;
+	} else {
+		die ("Misaligned FPU load inside kernel", regs, 0);
+		return -1;
+	}
+
+
+}
+
+static int misaligned_fpu_store(struct pt_regs *regs,
+			   __u32 opcode,
+			   int displacement_not_indexed,
+			   int width_shift,
+			   int do_paired_load)
+{
+	/* Return -1 for a fault, 0 for OK */
+	int error;
+	int srcreg;
+	__u64 address;
+
+	error = generate_and_check_address(regs, opcode,
+			displacement_not_indexed, width_shift, &address);
+	if (error < 0) {
+		return error;
+	}
+
+	srcreg = (opcode >> 4) & 0x3f;
+	if (user_mode(regs)) {
+		__u64 buffer;
+		/* Initialise these to NaNs. */
+		__u32 buflo=0xffffffffUL, bufhi=0xffffffffUL;
+
+		if (!access_ok(VERIFY_WRITE, (unsigned long) address, 1UL<<width_shift)) {
+			return -1;
+		}
+
+		/* 'current' may be the current owner of the FPU state, so
+		   context switch the registers into memory so they can be
+		   indexed by register number. */
+		if (last_task_used_math == current) {
+			grab_fpu();
+			fpsave(&current->thread.fpu.hard);
+			release_fpu();
+			last_task_used_math = NULL;
+			regs->sr |= SR_FD;
+		}
+
+		switch (width_shift) {
+		case 2:
+			buflo = current->thread.fpu.hard.fp_regs[srcreg];
+			break;
+		case 3:
+			if (do_paired_load) {
+				buflo = current->thread.fpu.hard.fp_regs[srcreg];
+				bufhi = current->thread.fpu.hard.fp_regs[srcreg+1];
+			} else {
+#if defined(CONFIG_LITTLE_ENDIAN)
+				bufhi = current->thread.fpu.hard.fp_regs[srcreg];
+				buflo = current->thread.fpu.hard.fp_regs[srcreg+1];
+#else
+				buflo = current->thread.fpu.hard.fp_regs[srcreg];
+				bufhi = current->thread.fpu.hard.fp_regs[srcreg+1];
+#endif
+			}
+			break;
+		default:
+			printk("Unexpected width_shift %d in misaligned_fpu_store, PC=%08lx\n",
+				width_shift, (unsigned long) regs->pc);
+			break;
+		}
+
+		*(__u32*) &buffer = buflo;
+		*(1 + (__u32*) &buffer) = bufhi;
+		if (__copy_user((void *)(int)address, &buffer, (1 << width_shift)) > 0) {
+			return -1; /* fault */
+		}
+		return 0;
+	} else {
+		die ("Misaligned FPU load inside kernel", regs, 0);
+		return -1;
+	}
+}
+#endif
+
+static int misaligned_fixup(struct pt_regs *regs)
+{
+	unsigned long opcode;
+	int error;
+	int major, minor;
+
+#if !defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
+	/* Never fixup user mode misaligned accesses without this option enabled. */
+	return -1;
+#else
+	if (!user_mode_unaligned_fixup_enable) return -1;
+#endif
+
+	error = read_opcode(regs->pc, &opcode, user_mode(regs));
+	if (error < 0) {
+		return error;
+	}
+	major = (opcode >> 26) & 0x3f;
+	minor = (opcode >> 16) & 0xf;
+
+#if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
+	if (user_mode(regs) && (user_mode_unaligned_fixup_count > 0)) {
+		--user_mode_unaligned_fixup_count;
+		/* Only do 'count' worth of these reports, to remove a potential DoS against syslog */
+		printk("Fixing up unaligned userspace access in \"%s\" pid=%d pc=0x%08x ins=0x%08lx\n",
+		       current->comm, task_pid_nr(current), (__u32)regs->pc, opcode);
+	} else
+#endif
+	if (!user_mode(regs) && (kernel_mode_unaligned_fixup_count > 0)) {
+		--kernel_mode_unaligned_fixup_count;
+		if (in_interrupt()) {
+			printk("Fixing up unaligned kernelspace access in interrupt pc=0x%08x ins=0x%08lx\n",
+			       (__u32)regs->pc, opcode);
+		} else {
+			printk("Fixing up unaligned kernelspace access in \"%s\" pid=%d pc=0x%08x ins=0x%08lx\n",
+			       current->comm, task_pid_nr(current), (__u32)regs->pc, opcode);
+		}
+	}
+
+
+	switch (major) {
+		case (0x84>>2): /* LD.W */
+			error = misaligned_load(regs, opcode, 1, 1, 1);
+			break;
+		case (0xb0>>2): /* LD.UW */
+			error = misaligned_load(regs, opcode, 1, 1, 0);
+			break;
+		case (0x88>>2): /* LD.L */
+			error = misaligned_load(regs, opcode, 1, 2, 1);
+			break;
+		case (0x8c>>2): /* LD.Q */
+			error = misaligned_load(regs, opcode, 1, 3, 0);
+			break;
+
+		case (0xa4>>2): /* ST.W */
+			error = misaligned_store(regs, opcode, 1, 1);
+			break;
+		case (0xa8>>2): /* ST.L */
+			error = misaligned_store(regs, opcode, 1, 2);
+			break;
+		case (0xac>>2): /* ST.Q */
+			error = misaligned_store(regs, opcode, 1, 3);
+			break;
+
+		case (0x40>>2): /* indexed loads */
+			switch (minor) {
+				case 0x1: /* LDX.W */
+					error = misaligned_load(regs, opcode, 0, 1, 1);
+					break;
+				case 0x5: /* LDX.UW */
+					error = misaligned_load(regs, opcode, 0, 1, 0);
+					break;
+				case 0x2: /* LDX.L */
+					error = misaligned_load(regs, opcode, 0, 2, 1);
+					break;
+				case 0x3: /* LDX.Q */
+					error = misaligned_load(regs, opcode, 0, 3, 0);
+					break;
+				default:
+					error = -1;
+					break;
+			}
+			break;
+
+		case (0x60>>2): /* indexed stores */
+			switch (minor) {
+				case 0x1: /* STX.W */
+					error = misaligned_store(regs, opcode, 0, 1);
+					break;
+				case 0x2: /* STX.L */
+					error = misaligned_store(regs, opcode, 0, 2);
+					break;
+				case 0x3: /* STX.Q */
+					error = misaligned_store(regs, opcode, 0, 3);
+					break;
+				default:
+					error = -1;
+					break;
+			}
+			break;
+
+#if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
+		case (0x94>>2): /* FLD.S */
+			error = misaligned_fpu_load(regs, opcode, 1, 2, 0);
+			break;
+		case (0x98>>2): /* FLD.P */
+			error = misaligned_fpu_load(regs, opcode, 1, 3, 1);
+			break;
+		case (0x9c>>2): /* FLD.D */
+			error = misaligned_fpu_load(regs, opcode, 1, 3, 0);
+			break;
+		case (0x1c>>2): /* floating indexed loads */
+			switch (minor) {
+			case 0x8: /* FLDX.S */
+				error = misaligned_fpu_load(regs, opcode, 0, 2, 0);
+				break;
+			case 0xd: /* FLDX.P */
+				error = misaligned_fpu_load(regs, opcode, 0, 3, 1);
+				break;
+			case 0x9: /* FLDX.D */
+				error = misaligned_fpu_load(regs, opcode, 0, 3, 0);
+				break;
+			default:
+				error = -1;
+				break;
+			}
+			break;
+		case (0xb4>>2): /* FLD.S */
+			error = misaligned_fpu_store(regs, opcode, 1, 2, 0);
+			break;
+		case (0xb8>>2): /* FLD.P */
+			error = misaligned_fpu_store(regs, opcode, 1, 3, 1);
+			break;
+		case (0xbc>>2): /* FLD.D */
+			error = misaligned_fpu_store(regs, opcode, 1, 3, 0);
+			break;
+		case (0x3c>>2): /* floating indexed stores */
+			switch (minor) {
+			case 0x8: /* FSTX.S */
+				error = misaligned_fpu_store(regs, opcode, 0, 2, 0);
+				break;
+			case 0xd: /* FSTX.P */
+				error = misaligned_fpu_store(regs, opcode, 0, 3, 1);
+				break;
+			case 0x9: /* FSTX.D */
+				error = misaligned_fpu_store(regs, opcode, 0, 3, 0);
+				break;
+			default:
+				error = -1;
+				break;
+			}
+			break;
+#endif
+
+		default:
+			/* Fault */
+			error = -1;
+			break;
+	}
+
+	if (error < 0) {
+		return error;
+	} else {
+		regs->pc += 4; /* Skip the instruction that's just been emulated */
+		return 0;
+	}
+
+}
+
+static ctl_table unaligned_table[] = {
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "kernel_reports",
+		.data		= &kernel_mode_unaligned_fixup_count,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+#if defined(CONFIG_SH64_USER_MISALIGNED_FIXUP)
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "user_reports",
+		.data		= &user_mode_unaligned_fixup_count,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "user_enable",
+		.data		= &user_mode_unaligned_fixup_enable,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec},
+#endif
+	{}
+};
+
+static ctl_table unaligned_root[] = {
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "unaligned_fixup",
+		.mode		= 0555,
+		unaligned_table
+	},
+	{}
+};
+
+static ctl_table sh64_root[] = {
+	{
+		.ctl_name	= CTL_UNNUMBERED,
+		.procname	= "sh64",
+		.mode		= 0555,
+		.child		= unaligned_root
+	},
+	{}
+};
+static struct ctl_table_header *sysctl_header;
+static int __init init_sysctl(void)
+{
+	sysctl_header = register_sysctl_table(sh64_root);
+	return 0;
+}
+
+__initcall(init_sysctl);
+
+
+asmlinkage void do_debug_interrupt(unsigned long code, struct pt_regs *regs)
+{
+	u64 peek_real_address_q(u64 addr);
+	u64 poke_real_address_q(u64 addr, u64 val);
+	unsigned long long DM_EXP_CAUSE_PHY = 0x0c100010;
+	unsigned long long exp_cause;
+	/* It's not worth ioremapping the debug module registers for the amount
+	   of access we make to them - just go direct to their physical
+	   addresses. */
+	exp_cause = peek_real_address_q(DM_EXP_CAUSE_PHY);
+	if (exp_cause & ~4) {
+		printk("DM.EXP_CAUSE had unexpected bits set (=%08lx)\n",
+			(unsigned long)(exp_cause & 0xffffffff));
+	}
+	show_state();
+	/* Clear all DEBUGINT causes */
+	poke_real_address_q(DM_EXP_CAUSE_PHY, 0x0);
+}