Merge branch 's3c-move' into devel

Conflicts:

	arch/arm/mach-versatile/core.c

2 files changed, 86 insertions, 37 deletions

diff --git a/arch/mn10300/kernel/irq.c b/arch/mn10300/kernel/irq.c
index 761c434a248..56c64ccc9c2 100644
--- a/arch/mn10300/kernel/irq.c
+++ b/arch/mn10300/kernel/irq.c
@@ -20,22 +20,8 @@ EXPORT_SYMBOL(__mn10300_irq_enabled_epsw);
 atomic_t irq_err_count;
 
 /*
- * MN10300 INTC controller operations
+ * MN10300 interrupt controller operations
  */
-static void mn10300_cpupic_disable(unsigned int irq)
-{
-	u16 tmp = GxICR(irq);
-	GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_DETECT;
-	tmp = GxICR(irq);
-}
-
-static void mn10300_cpupic_enable(unsigned int irq)
-{
-	u16 tmp = GxICR(irq);
-	GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE;
-	tmp = GxICR(irq);
-}
-
 static void mn10300_cpupic_ack(unsigned int irq)
 {
 	u16 tmp;
@@ -60,26 +46,54 @@ static void mn10300_cpupic_mask_ack(unsigned int irq)
 static void mn10300_cpupic_unmask(unsigned int irq)
 {
 	u16 tmp = GxICR(irq);
-	GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE | GxICR_DETECT;
+	GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE;
 	tmp = GxICR(irq);
 }
 
-static void mn10300_cpupic_end(unsigned int irq)
+static void mn10300_cpupic_unmask_clear(unsigned int irq)
 {
+	/* the MN10300 PIC latches its interrupt request bit, even after the
+	 * device has ceased to assert its interrupt line and the interrupt
+	 * channel has been disabled in the PIC, so for level-triggered
+	 * interrupts we need to clear the request bit when we re-enable */
 	u16 tmp = GxICR(irq);
-	GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE;
+	GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE | GxICR_DETECT;
 	tmp = GxICR(irq);
 }
 
-static struct irq_chip mn10300_cpu_pic = {
-	.name		= "cpu",
-	.disable	= mn10300_cpupic_disable,
-	.enable		= mn10300_cpupic_enable,
+/*
+ * MN10300 PIC level-triggered IRQ handling.
+ *
+ * The PIC has no 'ACK' function per se.  It is possible to clear individual
+ * channel latches, but each latch relatches whether or not the channel is
+ * masked, so we need to clear the latch when we unmask the channel.
+ *
+ * Also for this reason, we don't supply an ack() op (it's unused anyway if
+ * mask_ack() is provided), and mask_ack() just masks.
+ */
+static struct irq_chip mn10300_cpu_pic_level = {
+	.name		= "cpu_l",
+	.disable	= mn10300_cpupic_mask,
+	.enable		= mn10300_cpupic_unmask_clear,
+	.ack		= NULL,
+	.mask		= mn10300_cpupic_mask,
+	.mask_ack	= mn10300_cpupic_mask,
+	.unmask		= mn10300_cpupic_unmask_clear,
+};
+
+/*
+ * MN10300 PIC edge-triggered IRQ handling.
+ *
+ * We use the latch clearing function of the PIC as the 'ACK' function.
+ */
+static struct irq_chip mn10300_cpu_pic_edge = {
+	.name		= "cpu_e",
+	.disable	= mn10300_cpupic_mask,
+	.enable		= mn10300_cpupic_unmask,
 	.ack		= mn10300_cpupic_ack,
 	.mask		= mn10300_cpupic_mask,
 	.mask_ack	= mn10300_cpupic_mask_ack,
 	.unmask		= mn10300_cpupic_unmask,
-	.end		= mn10300_cpupic_end,
 };
 
 /*
@@ -114,7 +128,8 @@ void set_intr_level(int irq, u16 level)
  */
 void set_intr_postackable(int irq)
 {
-	set_irq_handler(irq, handle_level_irq);
+	set_irq_chip_and_handler(irq, &mn10300_cpu_pic_level,
+				 handle_level_irq);
 }
 
 /*
@@ -126,8 +141,12 @@ void __init init_IRQ(void)
 
 	for (irq = 0; irq < NR_IRQS; irq++)
 		if (irq_desc[irq].chip == &no_irq_type)
-			set_irq_chip_and_handler(irq, &mn10300_cpu_pic,
-						 handle_edge_irq);
+			/* due to the PIC latching interrupt requests, even
+			 * when the IRQ is disabled, IRQ_PENDING is superfluous
+			 * and we can use handle_level_irq() for edge-triggered
+			 * interrupts */
+			set_irq_chip_and_handler(irq, &mn10300_cpu_pic_edge,
+						 handle_level_irq);
 	unit_init_IRQ();
 }
 
diff --git a/arch/mn10300/kernel/time.c b/arch/mn10300/kernel/time.c
index babb7c2ac37..e4606586f94 100644
--- a/arch/mn10300/kernel/time.c
+++ b/arch/mn10300/kernel/time.c
@@ -1,6 +1,6 @@
 /* MN10300 Low level time management
  *
- * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2007-2008 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
  * - Derived from arch/i386/kernel/time.c
  *
@@ -16,6 +16,7 @@
 #include <linux/init.h>
 #include <linux/smp.h>
 #include <linux/profile.h>
+#include <linux/cnt32_to_63.h>
 #include <asm/irq.h>
 #include <asm/div64.h>
 #include <asm/processor.h>
@@ -40,27 +41,54 @@ static struct irqaction timer_irq = {
 	.name		= "timer",
 };
 
+static unsigned long sched_clock_multiplier;
+
 /*
  * scheduler clock - returns current time in nanosec units.
  */
 unsigned long long sched_clock(void)
 {
 	union {
-		unsigned long long l;
-		u32 w[2];
-	} quot;
+		unsigned long long ll;
+		unsigned l[2];
+	} tsc64, result;
+	unsigned long tsc, tmp;
+	unsigned product[3]; /* 96-bit intermediate value */
+
+	/* read the TSC value
+	 */
+	tsc = 0 - get_cycles(); /* get_cycles() counts down */
 
-	quot.w[0] = mn10300_last_tsc - get_cycles();
-	quot.w[1] = 1000000000;
+	/* expand to 64-bits.
+	 * - sched_clock() must be called once a minute or better or the
+	 *   following will go horribly wrong - see cnt32_to_63()
+	 */
+	tsc64.ll = cnt32_to_63(tsc) & 0x7fffffffffffffffULL;
 
-	asm("mulu %2,%3,%0,%1"
-	    : "=r"(quot.w[1]), "=r"(quot.w[0])
-	    : "0"(quot.w[1]), "1"(quot.w[0])
+	/* scale the 64-bit TSC value to a nanosecond value via a 96-bit
+	 * intermediate
+	 */
+	asm("mulu	%2,%0,%3,%0	\n"	/* LSW * mult ->  0:%3:%0 */
+	    "mulu	%2,%1,%2,%1	\n"	/* MSW * mult -> %2:%1:0 */
+	    "add	%3,%1		\n"
+	    "addc	0,%2		\n"	/* result in %2:%1:%0 */
+	    : "=r"(product[0]), "=r"(product[1]), "=r"(product[2]), "=r"(tmp)
+	    :  "0"(tsc64.l[0]),  "1"(tsc64.l[1]),  "2"(sched_clock_multiplier)
 	    : "cc");
 
-	do_div(quot.l, MN10300_TSCCLK);
+	result.l[0] = product[1] << 16 | product[0] >> 16;
+	result.l[1] = product[2] << 16 | product[1] >> 16;
 
-	return quot.l;
+	return result.ll;
+}
+
+/*
+ * initialise the scheduler clock
+ */
+static void __init mn10300_sched_clock_init(void)
+{
+	sched_clock_multiplier =
+		__muldiv64u(NSEC_PER_SEC, 1 << 16, MN10300_TSCCLK);
 }
 
 /*
@@ -128,4 +156,6 @@ void __init time_init(void)
 	/* start the watchdog timer */
 	watchdog_go();
 #endif
+
+	mn10300_sched_clock_init();
 }