Merge branch 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-…

…linus

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  [MIPS] Kconfig: Move missplaced NR_CPUS default from SMTC to VSMP.
  [MIPS] Lockdep: Fix recursion bug.
  [MIPS] RTLX: Handle copy_*_user return values.
  [MIPS] RTLX: Protect rtlx_{read,write} with mutex.
  [MIPS] RTLX: Harden against compiler reordering and optimization.
  [MIPS] RTLX: Don't use volatile; it's fragile.
  [MIPS] Lasat: Downgrade 64-bit kernel from experimental to broken.
  [MIPS] Compat: Fix build if CONFIG_SYSVIPC is disabled.
  [CHAR] lcd: Fix two warnings.
  [MIPS] FPU ownership management & preemption fixes
  [MIPS] Check FCSR for pending interrupts, alternative version
  [MIPS] IP27, IP35: Fix warnings.

arch/mips/Kconfig

@@ -250,7 +250,7 @@ config LASAT
 	select R5000_CPU_SCACHE
 	select SYS_HAS_CPU_R5000
 	select SYS_SUPPORTS_32BIT_KERNEL
-	select SYS_SUPPORTS_64BIT_KERNEL if EXPERIMENTAL
+	select SYS_SUPPORTS_64BIT_KERNEL if BROKEN
 	select SYS_SUPPORTS_LITTLE_ENDIAN
 	select GENERIC_HARDIRQS_NO__DO_IRQ
 
@@ -1559,6 +1559,7 @@ config MIPS_MT_SMP
 	select CPU_MIPSR2_IRQ_VI
 	select CPU_MIPSR2_SRS
 	select MIPS_MT
+	select NR_CPUS_DEFAULT_2
 	select SMP
 	select SYS_SUPPORTS_SMP
 	help
@@ -1573,7 +1574,6 @@ config MIPS_MT_SMTC
 	select CPU_MIPSR2_IRQ_VI
 	select CPU_MIPSR2_SRS
 	select MIPS_MT
-	select NR_CPUS_DEFAULT_2
 	select NR_CPUS_DEFAULT_8
 	select SMP
 	select SYS_SUPPORTS_SMP

arch/mips/kernel/kspd.c

@@ -191,6 +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;
@@ -201,15 +203,20 @@ 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;
 	}
 
 	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;
 		}
@@ -282,8 +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");
 }
 

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)
 {

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.

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)

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

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");
@@ -277,81 +289,88 @@ 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)
 		return(-ENOSYS);
 
 	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);