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] Fix wrong checksum for split TCP packets on 64-bit MIPS
  [MIPS] Fix BUG(), BUG_ON() handling
  [MIPS] Retry {save,restore}_fp_context if failed in atomic context.
  [MIPS] Disallow CpU exception in kernel again.
  [MIPS] Add missing silicon revisions for BCM112x

arch/mips/kernel/r2300_switch.S

@@ -49,7 +49,8 @@ LEAF(resume)
 #ifndef CONFIG_CPU_HAS_LLSC
 	sw      zero, ll_bit
 #endif
-	mfc0	t2, CP0_STATUS
+	mfc0	t1, CP0_STATUS
+	sw	t1, THREAD_STATUS(a0)
 	cpu_save_nonscratch a0
 	sw	ra, THREAD_REG31(a0)
 
@@ -59,8 +60,8 @@ LEAF(resume)
 	lw	t3, TASK_THREAD_INFO(a0)
 	lw	t0, TI_FLAGS(t3)
 	li	t1, _TIF_USEDFPU
-	and	t1, t0
+	and	t2, t0, t1
-	beqz	t1, 1f
+	beqz	t2, 1f
 	nor	t1, zero, t1
 
 	and	t0, t0, t1
@@ -73,13 +74,10 @@ 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_switch.S

@@ -48,7 +48,8 @@
 #ifndef CONFIG_CPU_HAS_LLSC
 	sw	zero, ll_bit
 #endif
-	mfc0	t2, CP0_STATUS
+	mfc0	t1, CP0_STATUS
+	LONG_S	t1, THREAD_STATUS(a0)
 	cpu_save_nonscratch a0
 	LONG_S	ra, THREAD_REG31(a0)
 
@@ -58,8 +59,8 @@
 	PTR_L	t3, TASK_THREAD_INFO(a0)
 	LONG_L	t0, TI_FLAGS(t3)
 	li	t1, _TIF_USEDFPU
-	and	t1, t0
+	and	t2, t0, t1
-	beqz	t1, 1f
+	beqz	t2, 1f
 	nor	t1, zero, t1
 
 	and	t0, t0, t1
@@ -72,13 +73,10 @@
 	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/signal-common.h

@@ -34,4 +34,13 @@ 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);
 
+/* Make sure we will not lose FPU ownership */
+#ifdef CONFIG_PREEMPT
+#define lock_fpu_owner()	preempt_disable()
+#define unlock_fpu_owner()	preempt_enable()
+#else
+#define lock_fpu_owner()	pagefault_disable()
+#define unlock_fpu_owner()	pagefault_enable()
+#endif
+
 #endif	/* __SIGNAL_COMMON_H */

arch/mips/kernel/signal.c

@@ -20,6 +20,7 @@
 #include <linux/ptrace.h>
 #include <linux/unistd.h>
 #include <linux/compiler.h>
+#include <linux/uaccess.h>
 
 #include <asm/abi.h>
 #include <asm/asm.h>
@@ -27,7 +28,6 @@
 #include <asm/cacheflush.h>
 #include <asm/fpu.h>
 #include <asm/sim.h>
-#include <asm/uaccess.h>
 #include <asm/ucontext.h>
 #include <asm/cpu-features.h>
 #include <asm/war.h>
@@ -78,6 +78,46 @@ struct rt_sigframe {
 /*
  * Helper routines
  */
+static int protected_save_fp_context(struct sigcontext __user *sc)
+{
+	int err;
+	while (1) {
+		lock_fpu_owner();
+		own_fpu_inatomic(1);
+		err = save_fp_context(sc); /* this might fail */
+		unlock_fpu_owner();
+		if (likely(!err))
+			break;
+		/* touch the sigcontext and try again */
+		err = __put_user(0, &sc->sc_fpregs[0]) |
+			__put_user(0, &sc->sc_fpregs[31]) |
+			__put_user(0, &sc->sc_fpc_csr);
+		if (err)
+			break;	/* really bad sigcontext */
+	}
+	return err;
+}
+
+static int protected_restore_fp_context(struct sigcontext __user *sc)
+{
+	int err, tmp;
+	while (1) {
+		lock_fpu_owner();
+		own_fpu_inatomic(0);
+		err = restore_fp_context(sc); /* this might fail */
+		unlock_fpu_owner();
+		if (likely(!err))
+			break;
+		/* touch the sigcontext and try again */
+		err = __get_user(tmp, &sc->sc_fpregs[0]) |
+			__get_user(tmp, &sc->sc_fpregs[31]) |
+			__get_user(tmp, &sc->sc_fpc_csr);
+		if (err)
+			break;	/* really bad sigcontext */
+	}
+	return err;
+}
+
 int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 {
 	int err = 0;
@@ -113,10 +153,7 @@ int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 		 * Save FPU state to signal context. Signal handler
 		 * will "inherit" current FPU state.
 		 */
-		own_fpu(1);
+		err |= protected_save_fp_context(sc);
-		enable_fp_in_kernel();
-		err |= save_fp_context(sc);
-		disable_fp_in_kernel();
 	}
 	return err;
 }
@@ -148,7 +185,7 @@ check_and_restore_fp_context(struct sigcontext __user *sc)
 	err = sig = fpcsr_pending(&sc->sc_fpc_csr);
 	if (err > 0)
 		err = 0;
-	err |= restore_fp_context(sc);
+	err |= protected_restore_fp_context(sc);
 	return err ?: sig;
 }
 
@@ -187,11 +224,8 @@ int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 
 	if (used_math) {
 		/* restore fpu context if we have used it before */
-		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(0);

arch/mips/kernel/signal32.c

@@ -22,6 +22,7 @@
 #include <linux/compat.h>
 #include <linux/suspend.h>
 #include <linux/compiler.h>
+#include <linux/uaccess.h>
 
 #include <asm/abi.h>
 #include <asm/asm.h>
@@ -29,7 +30,6 @@
 #include <linux/bitops.h>
 #include <asm/cacheflush.h>
 #include <asm/sim.h>
-#include <asm/uaccess.h>
 #include <asm/ucontext.h>
 #include <asm/system.h>
 #include <asm/fpu.h>
@@ -176,6 +176,46 @@ struct rt_sigframe32 {
 /*
  * sigcontext handlers
  */
+static int protected_save_fp_context32(struct sigcontext32 __user *sc)
+{
+	int err;
+	while (1) {
+		lock_fpu_owner();
+		own_fpu_inatomic(1);
+		err = save_fp_context32(sc); /* this might fail */
+		unlock_fpu_owner();
+		if (likely(!err))
+			break;
+		/* touch the sigcontext and try again */
+		err = __put_user(0, &sc->sc_fpregs[0]) |
+			__put_user(0, &sc->sc_fpregs[31]) |
+			__put_user(0, &sc->sc_fpc_csr);
+		if (err)
+			break;	/* really bad sigcontext */
+	}
+	return err;
+}
+
+static int protected_restore_fp_context32(struct sigcontext32 __user *sc)
+{
+	int err, tmp;
+	while (1) {
+		lock_fpu_owner();
+		own_fpu_inatomic(0);
+		err = restore_fp_context32(sc); /* this might fail */
+		unlock_fpu_owner();
+		if (likely(!err))
+			break;
+		/* touch the sigcontext and try again */
+		err = __get_user(tmp, &sc->sc_fpregs[0]) |
+			__get_user(tmp, &sc->sc_fpregs[31]) |
+			__get_user(tmp, &sc->sc_fpc_csr);
+		if (err)
+			break;	/* really bad sigcontext */
+	}
+	return err;
+}
+
 static int setup_sigcontext32(struct pt_regs *regs,
 			      struct sigcontext32 __user *sc)
 {
@@ -209,10 +249,7 @@ static int setup_sigcontext32(struct pt_regs *regs,
 		 * Save FPU state to signal context.  Signal handler
 		 * will "inherit" current FPU state.
 		 */
-		own_fpu(1);
+		err |= protected_save_fp_context32(sc);
-		enable_fp_in_kernel();
-		err |= save_fp_context32(sc);
-		disable_fp_in_kernel();
 	}
 	return err;
 }
@@ -225,7 +262,7 @@ check_and_restore_fp_context32(struct sigcontext32 __user *sc)
 	err = sig = fpcsr_pending(&sc->sc_fpc_csr);
 	if (err > 0)
 		err = 0;
-	err |= restore_fp_context32(sc);
+	err |= protected_restore_fp_context32(sc);
 	return err ?: sig;
 }
 
@@ -261,11 +298,8 @@ static int restore_sigcontext32(struct pt_regs *regs,
 
 	if (used_math) {
 		/* restore fpu context if we have used it before */
-		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(0);

arch/mips/kernel/traps.c

@@ -650,7 +650,7 @@ asmlinkage void do_bp(struct pt_regs *regs)
 	unsigned int opcode, bcode;
 	siginfo_t info;
 
-	if (get_user(opcode, (unsigned int __user *) exception_epc(regs)))
+	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
 		goto out_sigsegv;
 
 	/*
@@ -700,7 +700,7 @@ asmlinkage void do_tr(struct pt_regs *regs)
 	unsigned int opcode, tcode = 0;
 	siginfo_t info;
 
-	if (get_user(opcode, (unsigned int __user *) exception_epc(regs)))
+	if (__get_user(opcode, (unsigned int __user *) exception_epc(regs)))
 		goto out_sigsegv;
 
 	/* Immediate versions don't provide a code.  */
@@ -757,11 +757,12 @@ 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;
@@ -772,9 +773,6 @@ asmlinkage void do_cpu(struct pt_regs *regs)
 		break;
 
 	case 1:
-		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.  */
@@ -782,19 +780,7 @@ asmlinkage void do_cpu(struct pt_regs *regs)
 			set_used_math();
 		}
 
-		if (raw_cpu_has_fpu) {
+		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;
 			sig = fpu_emulator_cop1Handler(regs,
 						&current->thread.fpu, 0);
@@ -836,7 +822,6 @@ asmlinkage void do_cpu(struct pt_regs *regs)
 
 	case 2:
 	case 3:
-		die_if_kernel("do_cpu invoked from kernel context!", regs);
 		break;
 	}
 

arch/mips/sibyte/sb1250/setup.c

@@ -141,6 +141,18 @@ static int __init setup_bcm112x(void)
 		periph_rev = 3;
 		pass_str = "A2";
 		break;
+	case K_SYS_REVISION_BCM112x_A3:
+		periph_rev = 3;
+		pass_str = "A3";
+		break;
+	case K_SYS_REVISION_BCM112x_A4:
+		periph_rev = 3;
+		pass_str = "A4";
+		break;
+	case K_SYS_REVISION_BCM112x_B0:
+		periph_rev = 3;
+		pass_str = "B0";
+		break;
 	default:
 		printk("Unknown %s rev %x\n", soc_str, soc_pass);
 		ret = 1;

include/asm-mips/bug.h

@@ -18,7 +18,8 @@ do {									\
 
 #define BUG_ON(condition)						\
 do {									\
-	__asm__ __volatile__("tne $0, %0" : : "r" (condition));		\
+	__asm__ __volatile__("tne $0, %0, %1"				\
+			     : : "r" (condition), "i" (BRK_BUG));	\
 } while (0)
 
 #define HAVE_ARCH_BUG_ON

include/asm-mips/checksum.h

@@ -166,7 +166,7 @@ static inline __wsum csum_tcpudp_nofold(__be32 saddr,
 #else
 	  "r" (proto + len),
 #endif
-	  "r" (sum));
+	  "r" ((__force unsigned long)sum));
 
 	return sum;
 }

include/asm-mips/fpu.h

@@ -68,8 +68,6 @@ do {									\
 	/* We don't care about the c0 hazard here  */			\
 } while (0)
 
-#define __fpu_enabled()	(read_c0_status() & ST0_CU1)
-
 #define enable_fpu()							\
 do {									\
 	if (cpu_has_fpu)						\
@@ -102,14 +100,19 @@ static inline void __own_fpu(void)
 	set_thread_flag(TIF_USEDFPU);
 }
 
-static inline void own_fpu(int restore)
+static inline void own_fpu_inatomic(int restore)
 {
-	preempt_disable();
 	if (cpu_has_fpu && !__is_fpu_owner()) {
 		__own_fpu();
 		if (restore)
 			_restore_fp(current);
 	}
+}
+
+static inline void own_fpu(int restore)
+{
+	preempt_disable();
+	own_fpu_inatomic(restore);
 	preempt_enable();
 }
 
@@ -162,18 +165,4 @@ static inline fpureg_t *get_fpu_regs(struct task_struct *tsk)
 	return tsk->thread.fpu.fpr;
 }
 
-static inline void enable_fp_in_kernel(void)
-{
-	set_thread_flag(TIF_ALLOW_FP_IN_KERNEL);
-	/* make sure CU1 and FPU ownership are consistent */
-	if (!__is_fpu_owner() && __fpu_enabled())
-		__disable_fpu();
-}
-
-static inline void disable_fp_in_kernel(void)
-{
-	BUG_ON(!__is_fpu_owner() && __fpu_enabled());
-	clear_thread_flag(TIF_ALLOW_FP_IN_KERNEL);
-}
-
 #endif /* _ASM_FPU_H */

include/asm-mips/sibyte/sb1250_scd.h

@@ -84,6 +84,7 @@
 #define K_SYS_REVISION_BCM112x_A2	0x21
 #define K_SYS_REVISION_BCM112x_A3	0x22
 #define K_SYS_REVISION_BCM112x_A4	0x23
+#define K_SYS_REVISION_BCM112x_B0	0x30
 
 #define K_SYS_REVISION_BCM1480_S0	0x01
 #define K_SYS_REVISION_BCM1480_A1	0x02

include/asm-mips/thread_info.h

@@ -119,7 +119,6 @@ register struct thread_info *__current_thread_info __asm__("$28");
 #define TIF_POLLING_NRFLAG	17	/* true if poll_idle() is polling TIF_NEED_RESCHED */
 #define TIF_MEMDIE		18
 #define TIF_FREEZE		19
-#define TIF_ALLOW_FP_IN_KERNEL	20
 #define TIF_SYSCALL_TRACE	31	/* syscall trace active */
 
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)