Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus

Pull MIPS updates from Ralf Baechle:
 "This is the main pull request for MIPS for 4.5 plus some 4.4 fixes.

  The executive summary:

   - ATH79 platform improvments, use DT bindings for the ATH79 USB PHY.
   - Avoid useless rebuilds for zboot.
   - jz4780: Add NEMC, BCH and NAND device tree nodes
   - Initial support for the MicroChip's DT platform.  As all the device
     drivers are missing this is still of limited use.
   - Some Loongson3 cleanups.
   - The unavoidable whitespace polishing.
   - Reduce clock skew when synchronizing the CPU cycle counters on CPU
     startup.
   - Add MIPS R6 fixes.
   - Lots of cleanups across arch/mips as fallout from KVM.
   - Lots of minor fixes and changes for IEEE 754-2008 support to the
     FPU emulator / fp-assist software.
   - Minor Ralink, BCM47xx and bcm963xx platform support improvments.
   - Support SMP on BCM63168"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (84 commits)
  MIPS: zboot: Add support for serial debug using the PROM
  MIPS: zboot: Avoid useless rebuilds
  MIPS: BMIPS: Enable ARCH_WANT_OPTIONAL_GPIOLIB
  MIPS: bcm63xx: nvram: Remove unused bcm63xx_nvram_get_psi_size() function
  MIPS: bcm963xx: Update bcm_tag field image_sequence
  MIPS: bcm963xx: Move extended flash address to bcm_tag header file
  MIPS: bcm963xx: Move Broadcom BCM963xx image tag data structure
  MIPS: bcm63xx: nvram: Use nvram structure definition from header file
  MIPS: bcm963xx: Add Broadcom BCM963xx board nvram data structure
  MAINTAINERS: Add KVM for MIPS entry
  MIPS: KVM: Add missing newline to kvm_err()
  MIPS: Move KVM specific opcodes into asm/inst.h
  MIPS: KVM: Use cacheops.h definitions
  MIPS: Break down cacheops.h definitions
  MIPS: Use EXCCODE_ constants with set_except_vector()
  MIPS: Update trap codes
  MIPS: Move Cause.ExcCode trap codes to mipsregs.h
  MIPS: KVM: Make kvm_mips_{init,exit}() static
  MIPS: KVM: Refactor added offsetof()s
  MIPS: KVM: Convert EXPORT_SYMBOL to _GPL
  ...

1 files changed, 8 insertions, 24 deletions

diff --git a/arch/mips/kernel/sync-r4k.c b/arch/mips/kernel/sync-r4k.c
index 2242bdd4370e..4472a7f98577 100644
--- a/arch/mips/kernel/sync-r4k.c
+++ b/arch/mips/kernel/sync-r4k.c
@@ -17,35 +17,23 @@
 #include <asm/barrier.h>
 #include <asm/mipsregs.h>
 
-static atomic_t count_start_flag = ATOMIC_INIT(0);
+static unsigned int initcount = 0;
 static atomic_t count_count_start = ATOMIC_INIT(0);
 static atomic_t count_count_stop = ATOMIC_INIT(0);
-static atomic_t count_reference = ATOMIC_INIT(0);
 
 #define COUNTON 100
-#define NR_LOOPS 5
+#define NR_LOOPS 3
 
 void synchronise_count_master(int cpu)
 {
 	int i;
 	unsigned long flags;
-	unsigned int initcount;
 
 	printk(KERN_INFO "Synchronize counters for CPU %u: ", cpu);
 
 	local_irq_save(flags);
 
 	/*
-	 * Notify the slaves that it's time to start
-	 */
-	atomic_set(&count_reference, read_c0_count());
-	atomic_set(&count_start_flag, cpu);
-	smp_wmb();
-
-	/* Count will be initialised to current timer for all CPU's */
-	initcount = read_c0_count();
-
-	/*
 	 * We loop a few times to get a primed instruction cache,
 	 * then the last pass is more or less synchronised and
 	 * the master and slaves each set their cycle counters to a known
@@ -63,9 +51,13 @@ void synchronise_count_master(int cpu)
 		atomic_set(&count_count_stop, 0);
 		smp_wmb();
 
-		/* this lets the slaves write their count register */
+		/* Let the slave writes its count register */
 		atomic_inc(&count_count_start);
 
+		/* Count will be initialised to current timer */
+		if (i == 1)
+			initcount = read_c0_count();
+
 		/*
 		 * Everyone initialises count in the last loop:
 		 */
@@ -73,7 +65,7 @@ void synchronise_count_master(int cpu)
 			write_c0_count(initcount);
 
 		/*
-		 * Wait for all slaves to leave the synchronization point:
+		 * Wait for slave to leave the synchronization point:
 		 */
 		while (atomic_read(&count_count_stop) != 1)
 			mb();
@@ -83,7 +75,6 @@ void synchronise_count_master(int cpu)
 	}
 	/* Arrange for an interrupt in a short while */
 	write_c0_compare(read_c0_count() + COUNTON);
-	atomic_set(&count_start_flag, 0);
 
 	local_irq_restore(flags);
 
@@ -98,19 +89,12 @@ void synchronise_count_master(int cpu)
 void synchronise_count_slave(int cpu)
 {
 	int i;
-	unsigned int initcount;
 
 	/*
 	 * Not every cpu is online at the time this gets called,
 	 * so we first wait for the master to say everyone is ready
 	 */
 
-	while (atomic_read(&count_start_flag) != cpu)
-		mb();
-
-	/* Count will be initialised to next expire for all CPU's */
-	initcount = atomic_read(&count_reference);
-
 	for (i = 0; i < NR_LOOPS; i++) {
 		atomic_inc(&count_count_start);
 		while (atomic_read(&count_count_start) != 2)