Merge branch 'linux-2.6' into for-2.6.22

14 files changed, 341 insertions, 221 deletions

diff --git a/arch/mips/kernel/entry.S b/arch/mips/kernel/entry.S
index 0b78fcbf044a..686249c5c328 100644
--- a/arch/mips/kernel/entry.S
+++ b/arch/mips/kernel/entry.S
@@ -121,7 +121,11 @@ FEXPORT(restore_partial)		# restore partial frame
 	SAVE_AT
 	SAVE_TEMP
 	LONG_L	v0, PT_STATUS(sp)
-	and	v0, 1
+#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
+	and	v0, ST0_IEP
+#else
+	and	v0, ST0_IE
+#endif
 	beqz	v0, 1f
 	jal	trace_hardirqs_on
 	b	2f
diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S
index aacd4a005c5f..297bd56c2347 100644
--- a/arch/mips/kernel/genex.S
+++ b/arch/mips/kernel/genex.S
@@ -128,6 +128,37 @@ handle_vcei:
 
 	.align  5
 NESTED(handle_int, PT_SIZE, sp)
+#ifdef CONFIG_TRACE_IRQFLAGS
+	/*
+	 * Check to see if the interrupted code has just disabled
+	 * interrupts and ignore this interrupt for now if so.
+	 *
+	 * local_irq_disable() disables interrupts and then calls
+	 * trace_hardirqs_off() to track the state. If an interrupt is taken
+	 * after interrupts are disabled but before the state is updated
+	 * it will appear to restore_all that it is incorrectly returning with
+	 * interrupts disabled
+	 */
+	.set	push
+	.set	noat
+	mfc0	k0, CP0_STATUS
+#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
+	and	k0, ST0_IEP
+	bnez	k0, 1f
+
+	mfc0	k0, EP0_EPC
+	.set	noreorder
+	j	k0
+	rfe
+#else
+	and	k0, ST0_IE
+	bnez	k0, 1f
+
+	eret
+#endif
+1:
+	.set pop
+#endif
 	SAVE_ALL
 	CLI
 	TRACE_IRQS_OFF
@@ -181,13 +212,13 @@ NESTED(except_vec_vi, 0, sp)
 	 * during service by SMTC kernel, we also want to
 	 * pass the IM value to be cleared.
 	 */
-EXPORT(except_vec_vi_mori)
+FEXPORT(except_vec_vi_mori)
 	ori	a0, $0, 0
 #endif /* CONFIG_MIPS_MT_SMTC */
-EXPORT(except_vec_vi_lui)
+FEXPORT(except_vec_vi_lui)
 	lui	v0, 0		/* Patched */
 	j	except_vec_vi_handler
-EXPORT(except_vec_vi_ori)
+FEXPORT(except_vec_vi_ori)
 	 ori	v0, 0		/* Patched */
 	.set	pop
 	END(except_vec_vi)
@@ -220,7 +251,17 @@ NESTED(except_vec_vi_handler, 0, sp)
 	_ehb
 #endif /* CONFIG_MIPS_MT_SMTC */
 	CLI
+#ifdef CONFIG_TRACE_IRQFLAGS
+	move	s0, v0
+#ifdef CONFIG_MIPS_MT_SMTC
+	move	s1, a0
+#endif
 	TRACE_IRQS_OFF
+#ifdef CONFIG_MIPS_MT_SMTC
+	move	a0, s1
+#endif
+	move	v0, s0
+#endif
 
 	LONG_L	s0, TI_REGS($28)
 	LONG_S	sp, TI_REGS($28)
diff --git a/arch/mips/kernel/kspd.c b/arch/mips/kernel/kspd.c
index 5929f883e46b..29eadd404fa5 100644
--- a/arch/mips/kernel/kspd.c
+++ b/arch/mips/kernel/kspd.c
@@ -70,6 +70,7 @@ static int sp_stopping = 0;
 #define MTSP_SYSCALL_GETTIME	(MTSP_SYSCALL_BASE + 7)
 #define MTSP_SYSCALL_PIPEFREQ	(MTSP_SYSCALL_BASE + 8)
 #define MTSP_SYSCALL_GETTOD	(MTSP_SYSCALL_BASE + 9)
+#define MTSP_SYSCALL_IOCTL     (MTSP_SYSCALL_BASE + 10)
 
 #define MTSP_O_RDONLY		0x0000
 #define MTSP_O_WRONLY		0x0001
@@ -110,7 +111,8 @@ struct apsp_table syscall_command_table[] = {
 	{ MTSP_SYSCALL_CLOSE, __NR_close },
 	{ MTSP_SYSCALL_READ, __NR_read },
 	{ MTSP_SYSCALL_WRITE, __NR_write },
-	{ MTSP_SYSCALL_LSEEK32, __NR_lseek }
+	{ MTSP_SYSCALL_LSEEK32, __NR_lseek },
+	{ MTSP_SYSCALL_IOCTL, __NR_ioctl }
 };
 
 static int sp_syscall(int num, int arg0, int arg1, int arg2, int arg3)
@@ -189,6 +191,8 @@ void sp_work_handle_request(void)
 	struct mtsp_syscall_generic generic;
 	struct mtsp_syscall_ret ret;
 	struct kspd_notifications *n;
+	unsigned long written;
+	mm_segment_t old_fs;
 	struct timeval tv;
 	struct timezone tz;
 	int cmd;
@@ -199,7 +203,11 @@ void sp_work_handle_request(void)
 
 	ret.retval = -1;
 
-	if (!rtlx_read(RTLX_CHANNEL_SYSIO, &sc, sizeof(struct mtsp_syscall), 0)) {
+	old_fs = get_fs();
+	set_fs(KERNEL_DS);
+
+	if (!rtlx_read(RTLX_CHANNEL_SYSIO, &sc, sizeof(struct mtsp_syscall))) {
+		set_fs(old_fs);
 		printk(KERN_ERR "Expected request but nothing to read\n");
 		return;
 	}
@@ -207,7 +215,8 @@ void sp_work_handle_request(void)
 	size = sc.size;
 
 	if (size) {
-		if (!rtlx_read(RTLX_CHANNEL_SYSIO, &generic, size, 0)) {
+		if (!rtlx_read(RTLX_CHANNEL_SYSIO, &generic, size)) {
+			set_fs(old_fs);
 			printk(KERN_ERR "Expected request but nothing to read\n");
 			return;
 		}
@@ -280,8 +289,11 @@ void sp_work_handle_request(void)
 	if (vpe_getuid(SP_VPE))
 		sp_setfsuidgid( 0, 0);
 
-	if ((rtlx_write(RTLX_CHANNEL_SYSIO, &ret, sizeof(struct mtsp_syscall_ret), 0))
-	    < sizeof(struct mtsp_syscall_ret))
+	old_fs = get_fs();
+	set_fs(KERNEL_DS);
+	written = rtlx_write(RTLX_CHANNEL_SYSIO, &ret, sizeof(ret));
+	set_fs(old_fs);
+	if (written < sizeof(ret))
 		printk("KSPD: sp_work_handle_request failed to send to SP\n");
 }
 
diff --git a/arch/mips/kernel/linux32.c b/arch/mips/kernel/linux32.c
index 30d433f14f93..37849edd0645 100644
--- a/arch/mips/kernel/linux32.c
+++ b/arch/mips/kernel/linux32.c
@@ -311,6 +311,8 @@ asmlinkage int sys32_sched_rr_get_interval(compat_pid_t pid,
 	return ret;
 }
 
+#ifdef CONFIG_SYSVIPC
+
 asmlinkage long
 sys32_ipc (u32 call, int first, int second, int third, u32 ptr, u32 fifth)
 {
@@ -368,6 +370,16 @@ sys32_ipc (u32 call, int first, int second, int third, u32 ptr, u32 fifth)
 	return err;
 }
 
+#else
+
+asmlinkage long
+sys32_ipc (u32 call, int first, int second, int third, u32 ptr, u32 fifth)
+{
+	return -ENOSYS;
+}
+
+#endif /* CONFIG_SYSVIPC */
+
 #ifdef CONFIG_MIPS32_N32
 asmlinkage long sysn32_semctl(int semid, int semnum, int cmd, u32 arg)
 {
@@ -564,49 +576,3 @@ _sys32_clone(nabi_no_regargs struct pt_regs regs)
 	return do_fork(clone_flags, newsp, &regs, 0,
 	               parent_tidptr, child_tidptr);
 }
-
-/*
- * Implement the event wait interface for the eventpoll file. It is the kernel
- * part of the user space epoll_pwait(2).
- */
-asmlinkage long compat_sys_epoll_pwait(int epfd,
-	struct epoll_event __user *events, int maxevents, int timeout,
-	const compat_sigset_t __user *sigmask, size_t sigsetsize)
-{
-	int error;
-	sigset_t ksigmask, sigsaved;
-
-	/*
-	 * If the caller wants a certain signal mask to be set during the wait,
-	 * we apply it here.
-	 */
-	if (sigmask) {
-		if (sigsetsize != sizeof(sigset_t))
-			return -EINVAL;
-		if (!access_ok(VERIFY_READ, sigmask, sizeof(ksigmask)))
-			return -EFAULT;
-		if (__copy_conv_sigset_from_user(&ksigmask, sigmask))
-			return -EFAULT;
-		sigdelsetmask(&ksigmask, sigmask(SIGKILL) | sigmask(SIGSTOP));
-		sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
-	}
-
-	error = sys_epoll_wait(epfd, events, maxevents, timeout);
-
-	/*
-	 * If we changed the signal mask, we need to restore the original one.
-	 * In case we've got a signal while waiting, we do not restore the
-	 * signal mask yet, and we allow do_signal() to deliver the signal on
-	 * the way back to userspace, before the signal mask is restored.
-	 */
-	if (sigmask) {
-		if (error == -EINTR) {
-			memcpy(&current->saved_sigmask, &sigsaved,
-				sizeof(sigsaved));
-			set_thread_flag(TIF_RESTORE_SIGMASK);
-		} else
-			sigprocmask(SIG_SETMASK, &sigsaved, NULL);
-	}
-
-	return error;
-}
diff --git a/arch/mips/kernel/r2300_switch.S b/arch/mips/kernel/r2300_switch.S
index 656bde2e11b1..28c2e2e6af73 100644
--- a/arch/mips/kernel/r2300_switch.S
+++ b/arch/mips/kernel/r2300_switch.S
@@ -49,8 +49,7 @@ LEAF(resume)
 #ifndef CONFIG_CPU_HAS_LLSC
 	sw      zero, ll_bit
 #endif
-	mfc0	t1, CP0_STATUS
-	sw	t1, THREAD_STATUS(a0)
+	mfc0	t2, CP0_STATUS
 	cpu_save_nonscratch a0
 	sw	ra, THREAD_REG31(a0)
 
@@ -60,8 +59,8 @@ LEAF(resume)
 	lw	t3, TASK_THREAD_INFO(a0)
 	lw	t0, TI_FLAGS(t3)
 	li	t1, _TIF_USEDFPU
-	and	t2, t0, t1
-	beqz	t2, 1f
+	and	t1, t0
+	beqz	t1, 1f
 	nor	t1, zero, t1
 
 	and	t0, t0, t1
@@ -74,10 +73,13 @@ LEAF(resume)
 	li	t1, ~ST0_CU1
 	and	t0, t0, t1
 	sw	t0, ST_OFF(t3)
+	/* clear thread_struct CU1 bit */
+	and	t2, t1
 
 	fpu_save_single a0, t0			# clobbers t0
 
 1:
+	sw	t2, THREAD_STATUS(a0)
 	/*
 	 * The order of restoring the registers takes care of the race
 	 * updating $28, $29 and kernelsp without disabling ints.
diff --git a/arch/mips/kernel/r4k_fpu.S b/arch/mips/kernel/r4k_fpu.S
index 59c1577ecbb3..dbd42adc52ed 100644
--- a/arch/mips/kernel/r4k_fpu.S
+++ b/arch/mips/kernel/r4k_fpu.S
@@ -114,14 +114,6 @@ LEAF(_save_fp_context32)
  */
 LEAF(_restore_fp_context)
 	EX	lw t0, SC_FPC_CSR(a0)
-
-	/* Fail if the CSR has exceptions pending */
-	srl	t1, t0, 5
-	and	t1, t0
-	andi	t1, 0x1f << 7
-	bnez	t1, fault
-	 nop
-
 #ifdef CONFIG_64BIT
 	EX	ldc1 $f1, SC_FPREGS+8(a0)
 	EX	ldc1 $f3, SC_FPREGS+24(a0)
@@ -165,14 +157,6 @@ LEAF(_restore_fp_context)
 LEAF(_restore_fp_context32)
 	/* Restore an o32 sigcontext.  */
 	EX	lw t0, SC32_FPC_CSR(a0)
-
-	/* Fail if the CSR has exceptions pending */
-	srl	t1, t0, 5
-	and	t1, t0
-	andi	t1, 0x1f << 7
-	bnez	t1, fault
-	 nop
-
 	EX	ldc1 $f0, SC32_FPREGS+0(a0)
 	EX	ldc1 $f2, SC32_FPREGS+16(a0)
 	EX	ldc1 $f4, SC32_FPREGS+32(a0)
diff --git a/arch/mips/kernel/r4k_switch.S b/arch/mips/kernel/r4k_switch.S
index cc566cf12246..c7698fd9955c 100644
--- a/arch/mips/kernel/r4k_switch.S
+++ b/arch/mips/kernel/r4k_switch.S
@@ -48,8 +48,7 @@
 #ifndef CONFIG_CPU_HAS_LLSC
 	sw	zero, ll_bit
 #endif
-	mfc0	t1, CP0_STATUS
-	LONG_S	t1, THREAD_STATUS(a0)
+	mfc0	t2, CP0_STATUS
 	cpu_save_nonscratch a0
 	LONG_S	ra, THREAD_REG31(a0)
 
@@ -59,8 +58,8 @@
 	PTR_L	t3, TASK_THREAD_INFO(a0)
 	LONG_L	t0, TI_FLAGS(t3)
 	li	t1, _TIF_USEDFPU
-	and	t2, t0, t1
-	beqz	t2, 1f
+	and	t1, t0
+	beqz	t1, 1f
 	nor	t1, zero, t1
 
 	and	t0, t0, t1
@@ -73,10 +72,13 @@
 	li	t1, ~ST0_CU1
 	and	t0, t0, t1
 	LONG_S	t0, ST_OFF(t3)
+	/* clear thread_struct CU1 bit */
+	and	t2, t1
 
 	fpu_save_double a0 t0 t1		# c0_status passed in t0
 						# clobbers t1
 1:
+	LONG_S	t2, THREAD_STATUS(a0)
 
 	/*
 	 * The order of restoring the registers takes care of the race
diff --git a/arch/mips/kernel/rtlx.c b/arch/mips/kernel/rtlx.c
index e14ae09eda2b..e6e3047151a6 100644
--- a/arch/mips/kernel/rtlx.c
+++ b/arch/mips/kernel/rtlx.c
@@ -54,6 +54,7 @@ static struct chan_waitqueues {
 	wait_queue_head_t rt_queue;
 	wait_queue_head_t lx_queue;
 	atomic_t in_open;
+	struct mutex mutex;
 } channel_wqs[RTLX_CHANNELS];
 
 static struct irqaction irq;
@@ -146,7 +147,7 @@ static void stopping(int vpe)
 
 int rtlx_open(int index, int can_sleep)
 {
-	volatile struct rtlx_info **p;
+	struct rtlx_info **p;
 	struct rtlx_channel *chan;
 	enum rtlx_state state;
 	int ret = 0;
@@ -179,13 +180,24 @@ int rtlx_open(int index, int can_sleep)
 			}
 		}
 
+		smp_rmb();
 		if (*p == NULL) {
 			if (can_sleep) {
-				__wait_event_interruptible(channel_wqs[index].lx_queue,
-				                           *p != NULL,
-				                           ret);
-				if (ret)
+				DEFINE_WAIT(wait);
+
+				for (;;) {
+					prepare_to_wait(&channel_wqs[index].lx_queue, &wait, TASK_INTERRUPTIBLE);
+					smp_rmb();
+					if (*p != NULL)
+						break;
+					if (!signal_pending(current)) {
+						schedule();
+						continue;
+					}
+					ret = -ERESTARTSYS;
 					goto out_fail;
+				}
+				finish_wait(&channel_wqs[index].lx_queue, &wait);
 			} else {
 				printk(" *vpe_get_shared is NULL. "
 				       "Has an SP program been loaded?\n");
@@ -277,56 +289,52 @@ unsigned int rtlx_write_poll(int index)
 	return write_spacefree(chan->rt_read, chan->rt_write, chan->buffer_size);
 }
 
-static inline void copy_to(void *dst, void *src, size_t count, int user)
-{
-	if (user)
-		copy_to_user(dst, src, count);
-	else
-		memcpy(dst, src, count);
-}
-
-static inline void copy_from(void *dst, void *src, size_t count, int user)
+ssize_t rtlx_read(int index, void __user *buff, size_t count, int user)
 {
-	if (user)
-		copy_from_user(dst, src, count);
-	else
-		memcpy(dst, src, count);
-}
-
-ssize_t rtlx_read(int index, void *buff, size_t count, int user)
-{
-	size_t fl = 0L;
+	size_t lx_write, fl = 0L;
 	struct rtlx_channel *lx;
+	unsigned long failed;
 
 	if (rtlx == NULL)
 		return -ENOSYS;
 
 	lx = &rtlx->channel[index];
 
+	mutex_lock(&channel_wqs[index].mutex);
+	smp_rmb();
+	lx_write = lx->lx_write;
+
 	/* find out how much in total */
 	count = min(count,
-		     (size_t)(lx->lx_write + lx->buffer_size - lx->lx_read)
+		     (size_t)(lx_write + lx->buffer_size - lx->lx_read)
 		     % lx->buffer_size);
 
 	/* then how much from the read pointer onwards */
-	fl = min( count, (size_t)lx->buffer_size - lx->lx_read);
+	fl = min(count, (size_t)lx->buffer_size - lx->lx_read);
 
-	copy_to(buff, &lx->lx_buffer[lx->lx_read], fl, user);
+	failed = copy_to_user(buff, lx->lx_buffer + lx->lx_read, fl);
+	if (failed)
+		goto out;
 
 	/* and if there is anything left at the beginning of the buffer */
-	if ( count - fl )
-		copy_to (buff + fl, lx->lx_buffer, count - fl, user);
+	if (count - fl)
+		failed = copy_to_user(buff + fl, lx->lx_buffer, count - fl);
 
-	/* update the index */
-	lx->lx_read += count;
-	lx->lx_read %= lx->buffer_size;
+out:
+	count -= failed;
+
+	smp_wmb();
+	lx->lx_read = (lx->lx_read + count) % lx->buffer_size;
+	smp_wmb();
+	mutex_unlock(&channel_wqs[index].mutex);
 
 	return count;
 }
 
-ssize_t rtlx_write(int index, void *buffer, size_t count, int user)
+ssize_t rtlx_write(int index, const void __user *buffer, size_t count, int user)
 {
 	struct rtlx_channel *rt;
+	size_t rt_read;
 	size_t fl;
 
 	if (rtlx == NULL)
@@ -334,24 +342,35 @@ ssize_t rtlx_write(int index, void *buffer, size_t count, int user)
 
 	rt = &rtlx->channel[index];
 
+	mutex_lock(&channel_wqs[index].mutex);
+	smp_rmb();
+	rt_read = rt->rt_read;
+
 	/* total number of bytes to copy */
 	count = min(count,
-		    (size_t)write_spacefree(rt->rt_read, rt->rt_write,
-					    rt->buffer_size));
+		    (size_t)write_spacefree(rt_read, rt->rt_write, rt->buffer_size));
 
 	/* first bit from write pointer to the end of the buffer, or count */
 	fl = min(count, (size_t) rt->buffer_size - rt->rt_write);
 
-	copy_from (&rt->rt_buffer[rt->rt_write], buffer, fl, user);
+	failed = copy_from_user(rt->rt_buffer + rt->rt_write, buffer, fl);
+	if (failed)
+		goto out;
 
 	/* if there's any left copy to the beginning of the buffer */
-	if( count - fl )
-		copy_from (rt->rt_buffer, buffer + fl, count - fl, user);
+	if (count - fl) {
+		failed = copy_from_user(rt->rt_buffer, buffer + fl, count - fl);
+	}
+
+out:
+	count -= cailed;
 
-	rt->rt_write += count;
-	rt->rt_write %= rt->buffer_size;
+	smp_wmb();
+	rt->rt_write = (rt->rt_write + count) % rt->buffer_size;
+	smp_wmb();
+	mutex_unlock(&channel_wqs[index].mutex);
 
-	return(count);
+	return count;
 }
 
 
@@ -403,7 +422,7 @@ static ssize_t file_read(struct file *file, char __user * buffer, size_t count,
 		return 0;	// -EAGAIN makes cat whinge
 	}
 
-	return rtlx_read(minor, buffer, count, 1);
+	return rtlx_read(minor, buffer, count);
 }
 
 static ssize_t file_write(struct file *file, const char __user * buffer,
@@ -429,7 +448,7 @@ static ssize_t file_write(struct file *file, const char __user * buffer,
 			return ret;
 	}
 
-	return rtlx_write(minor, (void *)buffer, count, 1);
+	return rtlx_write(minor, buffer, count);
 }
 
 static const struct file_operations rtlx_fops = {
@@ -468,6 +487,7 @@ static int rtlx_module_init(void)
 		init_waitqueue_head(&channel_wqs[i].rt_queue);
 		init_waitqueue_head(&channel_wqs[i].lx_queue);
 		atomic_set(&channel_wqs[i].in_open, 0);
+		mutex_init(&channel_wqs[i].mutex);
 
 		dev = device_create(mt_class, NULL, MKDEV(major, i),
 		                    "%s%d", module_name, i);
diff --git a/arch/mips/kernel/signal-common.h b/arch/mips/kernel/signal-common.h
index fdbdbdc65b54..297dfcb97524 100644
--- a/arch/mips/kernel/signal-common.h
+++ b/arch/mips/kernel/signal-common.h
@@ -31,4 +31,7 @@ extern void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
  */
 extern int install_sigtramp(unsigned int __user *tramp, unsigned int syscall);
 
+/* Check and clear pending FPU exceptions in saved CSR */
+extern int fpcsr_pending(unsigned int __user *fpcsr);
+
 #endif	/* __SIGNAL_COMMON_H */
diff --git a/arch/mips/kernel/signal.c b/arch/mips/kernel/signal.c
index f091786187a6..8c3c5a5789b0 100644
--- a/arch/mips/kernel/signal.c
+++ b/arch/mips/kernel/signal.c
@@ -82,6 +82,7 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 {
 	int err = 0;
 	int i;
+	unsigned int used_math;
 
 	err |= __put_user(regs->cp0_epc, &sc->sc_pc);
 
@@ -104,26 +105,53 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 		err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
 	}
 
-	err |= __put_user(!!used_math(), &sc->sc_used_math);
+	used_math = !!used_math();
+	err |= __put_user(used_math, &sc->sc_used_math);
 
-	if (used_math()) {
+	if (used_math) {
 		/*
 		 * Save FPU state to signal context. Signal handler
 		 * will "inherit" current FPU state.
 		 */
-		preempt_disable();
-
-		if (!is_fpu_owner()) {
-			own_fpu();
-			restore_fp(current);
-		}
+		own_fpu(1);
+		enable_fp_in_kernel();
 		err |= save_fp_context(sc);
-
-		preempt_enable();
+		disable_fp_in_kernel();
 	}
 	return err;
 }
 
+int fpcsr_pending(unsigned int __user *fpcsr)
+{
+	int err, sig = 0;
+	unsigned int csr, enabled;
+
+	err = __get_user(csr, fpcsr);
+	enabled = FPU_CSR_UNI_X | ((csr & FPU_CSR_ALL_E) << 5);
+	/*
+	 * If the signal handler set some FPU exceptions, clear it and
+	 * send SIGFPE.
+	 */
+	if (csr & enabled) {
+		csr &= ~enabled;
+		err |= __put_user(csr, fpcsr);
+		sig = SIGFPE;
+	}
+	return err ?: sig;
+}
+
+static int
+check_and_restore_fp_context(struct sigcontext __user *sc)
+{
+	int err, sig;
+
+	err = sig = fpcsr_pending(&sc->sc_fpc_csr);
+	if (err > 0)
+		err = 0;
+	err |= restore_fp_context(sc);
+	return err ?: sig;
+}
+
 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 {
 	unsigned int used_math;
@@ -157,19 +185,18 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 	err |= __get_user(used_math, &sc->sc_used_math);
 	conditional_used_math(used_math);
 
-	preempt_disable();
-
-	if (used_math()) {
+	if (used_math) {
 		/* restore fpu context if we have used it before */
-		own_fpu();
-		err |= restore_fp_context(sc);
+		own_fpu(0);
+		enable_fp_in_kernel();
+		if (!err)
+			err = check_and_restore_fp_context(sc);
+		disable_fp_in_kernel();
 	} else {
 		/* signal handler may have used FPU.  Give it up. */
-		lose_fpu();
+		lose_fpu(0);
 	}
 
-	preempt_enable();
-
 	return err;
 }
 
@@ -332,6 +359,7 @@ asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
 {
 	struct sigframe __user *frame;
 	sigset_t blocked;
+	int sig;
 
 	frame = (struct sigframe __user *) regs.regs[29];
 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
@@ -345,8 +373,11 @@ asmlinkage void sys_sigreturn(nabi_no_regargs struct pt_regs regs)
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
-	if (restore_sigcontext(&regs, &frame->sf_sc))
+	sig = restore_sigcontext(&regs, &frame->sf_sc);
+	if (sig < 0)
 		goto badframe;
+	else if (sig)
+		force_sig(sig, current);
 
 	/*
 	 * Don't let your children do this ...
@@ -368,6 +399,7 @@ asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 	struct rt_sigframe __user *frame;
 	sigset_t set;
 	stack_t st;
+	int sig;
 
 	frame = (struct rt_sigframe __user *) regs.regs[29];
 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
@@ -381,8 +413,11 @@ asmlinkage void sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
-	if (restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext))
+	sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
+	if (sig < 0)
 		goto badframe;
+	else if (sig)
+		force_sig(sig, current);
 
 	if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st)))
 		goto badframe;
diff --git a/arch/mips/kernel/signal32.c b/arch/mips/kernel/signal32.c
index 19bbef001959..151fd2f0893a 100644
--- a/arch/mips/kernel/signal32.c
+++ b/arch/mips/kernel/signal32.c
@@ -181,6 +181,7 @@ static int setup_sigcontext32(struct pt_regs *regs,
 {
 	int err = 0;
 	int i;
+	u32 used_math;
 
 	err |= __put_user(regs->cp0_epc, &sc->sc_pc);
 
@@ -200,26 +201,34 @@ static int setup_sigcontext32(struct pt_regs *regs,
 		err |= __put_user(mflo3(), &sc->sc_lo3);
 	}
 
-	err |= __put_user(!!used_math(), &sc->sc_used_math);
+	used_math = !!used_math();
+	err |= __put_user(used_math, &sc->sc_used_math);
 
-	if (used_math()) {
+	if (used_math) {
 		/*
 		 * Save FPU state to signal context.  Signal handler
 		 * will "inherit" current FPU state.
 		 */
-		preempt_disable();
-
-		if (!is_fpu_owner()) {
-			own_fpu();
-			restore_fp(current);
-		}
+		own_fpu(1);
+		enable_fp_in_kernel();
 		err |= save_fp_context32(sc);
-
-		preempt_enable();
+		disable_fp_in_kernel();
 	}
 	return err;
 }
 
+static int
+check_and_restore_fp_context32(struct sigcontext32 __user *sc)
+{
+	int err, sig;
+
+	err = sig = fpcsr_pending(&sc->sc_fpc_csr);
+	if (err > 0)
+		err = 0;
+	err |= restore_fp_context32(sc);
+	return err ?: sig;
+}
+
 static int restore_sigcontext32(struct pt_regs *regs,
 				struct sigcontext32 __user *sc)
 {
@@ -250,19 +259,18 @@ static int restore_sigcontext32(struct pt_regs *regs,
 	err |= __get_user(used_math, &sc->sc_used_math);
 	conditional_used_math(used_math);
 
-	preempt_disable();
-
-	if (used_math()) {
+	if (used_math) {
 		/* restore fpu context if we have used it before */
-		own_fpu();
-		err |= restore_fp_context32(sc);
+		own_fpu(0);
+		enable_fp_in_kernel();
+		if (!err)
+			err = check_and_restore_fp_context32(sc);
+		disable_fp_in_kernel();
 	} else {
 		/* signal handler may have used FPU.  Give it up. */
-		lose_fpu();
+		lose_fpu(0);
 	}
 
-	preempt_enable();
-
 	return err;
 }
 
@@ -508,6 +516,7 @@ asmlinkage void sys32_sigreturn(nabi_no_regargs struct pt_regs regs)
 {
 	struct sigframe32 __user *frame;
 	sigset_t blocked;
+	int sig;
 
 	frame = (struct sigframe32 __user *) regs.regs[29];
 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
@@ -521,8 +530,11 @@ asmlinkage void sys32_sigreturn(nabi_no_regargs struct pt_regs regs)
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
-	if (restore_sigcontext32(&regs, &frame->sf_sc))
+	sig = restore_sigcontext32(&regs, &frame->sf_sc);
+	if (sig < 0)
 		goto badframe;
+	else if (sig)
+		force_sig(sig, current);
 
 	/*
 	 * Don't let your children do this ...
@@ -545,6 +557,7 @@ asmlinkage void sys32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 	sigset_t set;
 	stack_t st;
 	s32 sp;
+	int sig;
 
 	frame = (struct rt_sigframe32 __user *) regs.regs[29];
 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
@@ -558,8 +571,11 @@ asmlinkage void sys32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
-	if (restore_sigcontext32(&regs, &frame->rs_uc.uc_mcontext))
+	sig = restore_sigcontext32(&regs, &frame->rs_uc.uc_mcontext);
+	if (sig < 0)
 		goto badframe;
+	else if (sig)
+		force_sig(sig, current);
 
 	/* The ucontext contains a stack32_t, so we must convert!  */
 	if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
diff --git a/arch/mips/kernel/signal_n32.c b/arch/mips/kernel/signal_n32.c
index ecf1f7ecaad9..a9202fa95987 100644
--- a/arch/mips/kernel/signal_n32.c
+++ b/arch/mips/kernel/signal_n32.c
@@ -127,6 +127,7 @@ asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 	sigset_t set;
 	stack_t st;
 	s32 sp;
+	int sig;
 
 	frame = (struct rt_sigframe_n32 __user *) regs.regs[29];
 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
@@ -140,8 +141,11 @@ asmlinkage void sysn32_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 
-	if (restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext))
+	sig = restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext);
+	if (sig < 0)
 		goto badframe;
+	else if (sig)
+		force_sig(sig, current);
 
 	/* The ucontext contains a stack32_t, so we must convert!  */
 	if (__get_user(sp, &frame->rs_uc.uc_stack.ss_sp))
diff --git a/arch/mips/kernel/smtc.c b/arch/mips/kernel/smtc.c
index f253eda27fa3..5dcfab6b288e 100644
--- a/arch/mips/kernel/smtc.c
+++ b/arch/mips/kernel/smtc.c
@@ -4,6 +4,7 @@
 #include <linux/sched.h>
 #include <linux/cpumask.h>
 #include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
 #include <linux/module.h>
 
 #include <asm/cpu.h>
@@ -14,6 +15,7 @@
 #include <asm/hazards.h>
 #include <asm/mmu_context.h>
 #include <asm/smp.h>
+#include <asm/mips-boards/maltaint.h>
 #include <asm/mipsregs.h>
 #include <asm/cacheflush.h>
 #include <asm/time.h>
@@ -75,7 +77,7 @@ static struct smtc_ipi_q freeIPIq;
 
 void ipi_decode(struct smtc_ipi *);
 static void post_direct_ipi(int cpu, struct smtc_ipi *pipi);
-static void setup_cross_vpe_interrupts(void);
+static void setup_cross_vpe_interrupts(unsigned int nvpe);
 void init_smtc_stats(void);
 
 /* Global SMTC Status */
@@ -168,7 +170,10 @@ __setup("tintq=", tintq);
 
 int imstuckcount[2][8];
 /* vpemask represents IM/IE bits of per-VPE Status registers, low-to-high */
-int vpemask[2][8] = {{0,1,1,0,0,0,0,1},{0,1,0,0,0,0,0,1}};
+int vpemask[2][8] = {
+	{0, 0, 1, 0, 0, 0, 0, 1},
+	{0, 0, 0, 0, 0, 0, 0, 1}
+};
 int tcnoprog[NR_CPUS];
 static atomic_t idle_hook_initialized = {0};
 static int clock_hang_reported[NR_CPUS];
@@ -501,8 +506,7 @@ void mipsmt_prepare_cpus(void)
 
 	/* If we have multiple VPEs running, set up the cross-VPE interrupt */
 
-	if (nvpe > 1)
-		setup_cross_vpe_interrupts();
+	setup_cross_vpe_interrupts(nvpe);
 
 	/* Set up queue of free IPI "messages". */
 	nipi = NR_CPUS * IPIBUF_PER_CPU;
@@ -607,7 +611,12 @@ void smtc_cpus_done(void)
 int setup_irq_smtc(unsigned int irq, struct irqaction * new,
 			unsigned long hwmask)
 {
+	unsigned int vpe = current_cpu_data.vpe_id;
+
 	irq_hwmask[irq] = hwmask;
+#ifdef CONFIG_SMTC_IDLE_HOOK_DEBUG
+	vpemask[vpe][irq - MIPSCPU_INT_BASE] = 1;
+#endif
 
 	return setup_irq(irq, new);
 }
@@ -812,12 +821,15 @@ void ipi_decode(struct smtc_ipi *pipi)
 	smtc_ipi_nq(&freeIPIq, pipi);
 	switch (type_copy) {
 	case SMTC_CLOCK_TICK:
+		irq_enter();
+		kstat_this_cpu.irqs[MIPSCPU_INT_BASE + MIPSCPU_INT_CPUCTR]++;
 		/* Invoke Clock "Interrupt" */
 		ipi_timer_latch[dest_copy] = 0;
 #ifdef CONFIG_SMTC_IDLE_HOOK_DEBUG
 		clock_hang_reported[dest_copy] = 0;
 #endif /* CONFIG_SMTC_IDLE_HOOK_DEBUG */
 		local_timer_interrupt(0, NULL);
+		irq_exit();
 		break;
 	case LINUX_SMP_IPI:
 		switch ((int)arg_copy) {
@@ -965,8 +977,11 @@ static void ipi_irq_dispatch(void)
 
 static struct irqaction irq_ipi;
 
-static void setup_cross_vpe_interrupts(void)
+static void setup_cross_vpe_interrupts(unsigned int nvpe)
 {
+	if (nvpe < 1)
+		return;
+
 	if (!cpu_has_vint)
 		panic("SMTC Kernel requires Vectored Interupt support");
 
@@ -984,10 +999,17 @@ static void setup_cross_vpe_interrupts(void)
 
 /*
  * SMTC-specific hacks invoked from elsewhere in the kernel.
+ *
+ * smtc_ipi_replay is called from raw_local_irq_restore which is only ever
+ * called with interrupts disabled.  We do rely on interrupts being disabled
+ * here because using spin_lock_irqsave()/spin_unlock_irqrestore() would
+ * result in a recursive call to raw_local_irq_restore().
  */
 
-void smtc_ipi_replay(void)
+static void __smtc_ipi_replay(void)
 {
+	unsigned int cpu = smp_processor_id();
+
 	/*
 	 * To the extent that we've ever turned interrupts off,
 	 * we may have accumulated deferred IPIs.  This is subtle.
@@ -1002,17 +1024,30 @@ void smtc_ipi_replay(void)
 	 * is clear, and we'll handle it as a real pseudo-interrupt
 	 * and not a pseudo-pseudo interrupt.
 	 */
-	if (IPIQ[smp_processor_id()].depth > 0) {
-		struct smtc_ipi *pipi;
-		extern void self_ipi(struct smtc_ipi *);
+	if (IPIQ[cpu].depth > 0) {
+		while (1) {
+			struct smtc_ipi_q *q = &IPIQ[cpu];
+			struct smtc_ipi *pipi;
+			extern void self_ipi(struct smtc_ipi *);
+
+			spin_lock(&q->lock);
+			pipi = __smtc_ipi_dq(q);
+			spin_unlock(&q->lock);
+			if (!pipi)
+				break;
 
-		while ((pipi = smtc_ipi_dq(&IPIQ[smp_processor_id()]))) {
 			self_ipi(pipi);
-			smtc_cpu_stats[smp_processor_id()].selfipis++;
+			smtc_cpu_stats[cpu].selfipis++;
 		}
 	}
 }
 
+void smtc_ipi_replay(void)
+{
+	raw_local_irq_disable();
+	__smtc_ipi_replay();
+}
+
 EXPORT_SYMBOL(smtc_ipi_replay);
 
 void smtc_idle_loop_hook(void)
@@ -1117,7 +1152,13 @@ void smtc_idle_loop_hook(void)
 	 * is in use, there should never be any.
 	 */
 #ifndef CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY
-	smtc_ipi_replay();
+	{
+		unsigned long flags;
+
+		local_irq_save(flags);
+		__smtc_ipi_replay();
+		local_irq_restore(flags);
+	}
 #endif /* CONFIG_MIPS_MT_SMTC_INSTANT_REPLAY */
 }
 
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 18f56a9dbcfa..7d76a85422b2 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -610,16 +610,6 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
 	if (fcr31 & FPU_CSR_UNI_X) {
 		int sig;
 
-		preempt_disable();
-
-#ifdef CONFIG_PREEMPT
-		if (!is_fpu_owner()) {
-			/* We might lose fpu before disabling preempt... */
-			own_fpu();
-			BUG_ON(!used_math());
-			restore_fp(current);
-		}
-#endif
 		/*
 		 * Unimplemented operation exception.  If we've got the full
 		 * software emulator on-board, let's use it...
@@ -630,18 +620,12 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
 		 * register operands before invoking the emulator, which seems
 		 * a bit extreme for what should be an infrequent event.
 		 */
-		save_fp(current);
 		/* Ensure 'resume' not overwrite saved fp context again. */
-		lose_fpu();
-
-		preempt_enable();
+		lose_fpu(1);
 
 		/* Run the emulator */
 		sig = fpu_emulator_cop1Handler (regs, &current->thread.fpu, 1);
 
-		preempt_disable();
-
-		own_fpu();	/* Using the FPU again.  */
 		/*
 		 * We can't allow the emulated instruction to leave any of
 		 * the cause bit set in $fcr31.
@@ -649,9 +633,7 @@ asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
 		current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
 
 		/* Restore the hardware register state */
-		restore_fp(current);
-
-		preempt_enable();
+		own_fpu(1);	/* Using the FPU again.  */
 
 		/* If something went wrong, signal */
 		if (sig)
@@ -775,12 +757,11 @@ asmlinkage void do_cpu(struct pt_regs *regs)
 {
 	unsigned int cpid;
 
-	die_if_kernel("do_cpu invoked from kernel context!", regs);
-
 	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
 
 	switch (cpid) {
 	case 0:
+		die_if_kernel("do_cpu invoked from kernel context!", regs);
 		if (!cpu_has_llsc)
 			if (!simulate_llsc(regs))
 				return;
@@ -791,21 +772,30 @@ asmlinkage void do_cpu(struct pt_regs *regs)
 		break;
 
 	case 1:
-		preempt_disable();
-
-		own_fpu();
-		if (used_math()) {	/* Using the FPU again.  */
-			restore_fp(current);
-		} else {			/* First time FPU user.  */
+		if (!test_thread_flag(TIF_ALLOW_FP_IN_KERNEL))
+			die_if_kernel("do_cpu invoked from kernel context!",
+				      regs);
+		if (used_math())	/* Using the FPU again.  */
+			own_fpu(1);
+		else {			/* First time FPU user.  */
 			init_fpu();
 			set_used_math();
 		}
 
-		if (cpu_has_fpu) {
-			preempt_enable();
+		if (raw_cpu_has_fpu) {
+			if (test_thread_flag(TIF_ALLOW_FP_IN_KERNEL)) {
+				local_irq_disable();
+				if (cpu_has_fpu)
+					regs->cp0_status |= ST0_CU1;
+				/*
+				 * We must return without enabling
+				 * interrupts to ensure keep FPU
+				 * ownership until resume.
+				 */
+				return;
+			}
 		} else {
 			int sig;
-			preempt_enable();
 			sig = fpu_emulator_cop1Handler(regs,
 						&current->thread.fpu, 0);
 			if (sig)
@@ -1259,26 +1249,26 @@ static inline void mips_srs_init(void)
 /*
  * This is used by native signal handling
  */
-asmlinkage int (*save_fp_context)(struct sigcontext *sc);
-asmlinkage int (*restore_fp_context)(struct sigcontext *sc);
+asmlinkage int (*save_fp_context)(struct sigcontext __user *sc);
+asmlinkage int (*restore_fp_context)(struct sigcontext __user *sc);
 
-extern asmlinkage int _save_fp_context(struct sigcontext *sc);
-extern asmlinkage int _restore_fp_context(struct sigcontext *sc);
+extern asmlinkage int _save_fp_context(struct sigcontext __user *sc);
+extern asmlinkage int _restore_fp_context(struct sigcontext __user *sc);
 
-extern asmlinkage int fpu_emulator_save_context(struct sigcontext *sc);
-extern asmlinkage int fpu_emulator_restore_context(struct sigcontext *sc);
+extern asmlinkage int fpu_emulator_save_context(struct sigcontext __user *sc);
+extern asmlinkage int fpu_emulator_restore_context(struct sigcontext __user *sc);
 
 #ifdef CONFIG_SMP
-static int smp_save_fp_context(struct sigcontext *sc)
+static int smp_save_fp_context(struct sigcontext __user *sc)
 {
-	return cpu_has_fpu
+	return raw_cpu_has_fpu
 	       ? _save_fp_context(sc)
 	       : fpu_emulator_save_context(sc);
 }
 
-static int smp_restore_fp_context(struct sigcontext *sc)
+static int smp_restore_fp_context(struct sigcontext __user *sc)
 {
-	return cpu_has_fpu
+	return raw_cpu_has_fpu
 	       ? _restore_fp_context(sc)
 	       : fpu_emulator_restore_context(sc);
 }
@@ -1306,14 +1296,14 @@ static inline void signal_init(void)
 /*
  * This is used by 32-bit signal stuff on the 64-bit kernel
  */
-asmlinkage int (*save_fp_context32)(struct sigcontext32 *sc);
-asmlinkage int (*restore_fp_context32)(struct sigcontext32 *sc);
+asmlinkage int (*save_fp_context32)(struct sigcontext32 __user *sc);
+asmlinkage int (*restore_fp_context32)(struct sigcontext32 __user *sc);
 
-extern asmlinkage int _save_fp_context32(struct sigcontext32 *sc);
-extern asmlinkage int _restore_fp_context32(struct sigcontext32 *sc);
+extern asmlinkage int _save_fp_context32(struct sigcontext32 __user *sc);
+extern asmlinkage int _restore_fp_context32(struct sigcontext32 __user *sc);
 
-extern asmlinkage int fpu_emulator_save_context32(struct sigcontext32 *sc);
-extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 *sc);
+extern asmlinkage int fpu_emulator_save_context32(struct sigcontext32 __user *sc);
+extern asmlinkage int fpu_emulator_restore_context32(struct sigcontext32 __user *sc);
 
 static inline void signal32_init(void)
 {