Merge branch 'smp' into misc

Conflicts:
	arch/arm/kernel/entry-armv.S
	arch/arm/mm/ioremap.c

3 files changed, 53 insertions, 110 deletions

diff --git a/arch/arm/mach-realview/hotplug.c b/arch/arm/mach-realview/hotplug.c
index f95521a..a87523d 100644
--- a/arch/arm/mach-realview/hotplug.c
+++ b/arch/arm/mach-realview/hotplug.c
@@ -11,14 +11,11 @@
 #include <linux/kernel.h>
 #include <linux/errno.h>
 #include <linux/smp.h>
-#include <linux/completion.h>
 
 #include <asm/cacheflush.h>
 
 extern volatile int pen_release;
 
-static DECLARE_COMPLETION(cpu_killed);
-
 static inline void cpu_enter_lowpower(void)
 {
 	unsigned int v;
@@ -34,10 +31,10 @@ static inline void cpu_enter_lowpower(void)
 	"	bic	%0, %0, #0x20\n"
 	"	mcr	p15, 0, %0, c1, c0, 1\n"
 	"	mrc	p15, 0, %0, c1, c0, 0\n"
-	"	bic	%0, %0, #0x04\n"
+	"	bic	%0, %0, %2\n"
 	"	mcr	p15, 0, %0, c1, c0, 0\n"
 	  : "=&r" (v)
-	  : "r" (0)
+	  : "r" (0), "Ir" (CR_C)
 	  : "cc");
 }
 
@@ -46,17 +43,17 @@ static inline void cpu_leave_lowpower(void)
 	unsigned int v;
 
 	asm volatile(	"mrc	p15, 0, %0, c1, c0, 0\n"
-	"	orr	%0, %0, #0x04\n"
+	"	orr	%0, %0, %1\n"
 	"	mcr	p15, 0, %0, c1, c0, 0\n"
 	"	mrc	p15, 0, %0, c1, c0, 1\n"
 	"	orr	%0, %0, #0x20\n"
 	"	mcr	p15, 0, %0, c1, c0, 1\n"
 	  : "=&r" (v)
-	  :
+	  : "Ir" (CR_C)
 	  : "cc");
 }
 
-static inline void platform_do_lowpower(unsigned int cpu)
+static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
 {
 	/*
 	 * there is no power-control hardware on this platform, so all
@@ -80,22 +77,19 @@ static inline void platform_do_lowpower(unsigned int cpu)
 		}
 
 		/*
-		 * getting here, means that we have come out of WFI without
+		 * Getting here, means that we have come out of WFI without
 		 * having been woken up - this shouldn't happen
 		 *
-		 * The trouble is, letting people know about this is not really
-		 * possible, since we are currently running incoherently, and
-		 * therefore cannot safely call printk() or anything else
+		 * Just note it happening - when we're woken, we can report
+		 * its occurrence.
 		 */
-#ifdef DEBUG
-		printk("CPU%u: spurious wakeup call\n", cpu);
-#endif
+		(*spurious)++;
 	}
 }
 
 int platform_cpu_kill(unsigned int cpu)
 {
-	return wait_for_completion_timeout(&cpu_killed, 5000);
+	return 1;
 }
 
 /*
@@ -105,30 +99,22 @@ int platform_cpu_kill(unsigned int cpu)
  */
 void platform_cpu_die(unsigned int cpu)
 {
-#ifdef DEBUG
-	unsigned int this_cpu = hard_smp_processor_id();
-
-	if (cpu != this_cpu) {
-		printk(KERN_CRIT "Eek! platform_cpu_die running on %u, should be %u\n",
-			   this_cpu, cpu);
-		BUG();
-	}
-#endif
-
-	printk(KERN_NOTICE "CPU%u: shutdown\n", cpu);
-	complete(&cpu_killed);
+	int spurious = 0;
 
 	/*
 	 * we're ready for shutdown now, so do it
 	 */
 	cpu_enter_lowpower();
-	platform_do_lowpower(cpu);
+	platform_do_lowpower(cpu, &spurious);
 
 	/*
 	 * bring this CPU back into the world of cache
 	 * coherency, and then restore interrupts
 	 */
 	cpu_leave_lowpower();
+
+	if (spurious)
+		pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
 }
 
 int platform_cpu_disable(unsigned int cpu)
diff --git a/arch/arm/mach-realview/include/mach/smp.h b/arch/arm/mach-realview/include/mach/smp.h
index d3cd265..c8221b3 100644
--- a/arch/arm/mach-realview/include/mach/smp.h
+++ b/arch/arm/mach-realview/include/mach/smp.h
@@ -2,14 +2,13 @@
 #define ASMARM_ARCH_SMP_H
 
 #include <asm/hardware/gic.h>
-#include <asm/smp_mpidr.h>
 
 /*
  * We use IRQ1 as the IPI
  */
-static inline void smp_cross_call(const struct cpumask *mask)
+static inline void smp_cross_call(const struct cpumask *mask, int ipi)
 {
-	gic_raise_softirq(mask, 1);
+	gic_raise_softirq(mask, ipi);
 }
 
 #endif
diff --git a/arch/arm/mach-realview/platsmp.c b/arch/arm/mach-realview/platsmp.c
index 0092658..bb8d6c4 100644
--- a/arch/arm/mach-realview/platsmp.c
+++ b/arch/arm/mach-realview/platsmp.c
@@ -19,7 +19,6 @@
 #include <asm/cacheflush.h>
 #include <mach/hardware.h>
 #include <asm/mach-types.h>
-#include <asm/localtimer.h>
 #include <asm/unified.h>
 
 #include <mach/board-eb.h>
@@ -37,6 +36,19 @@ extern void realview_secondary_startup(void);
  */
 volatile int __cpuinitdata pen_release = -1;
 
+/*
+ * Write pen_release in a way that is guaranteed to be visible to all
+ * observers, irrespective of whether they're taking part in coherency
+ * or not.  This is necessary for the hotplug code to work reliably.
+ */
+static void write_pen_release(int val)
+{
+	pen_release = val;
+	smp_wmb();
+	__cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release));
+	outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
+}
+
 static void __iomem *scu_base_addr(void)
 {
 	if (machine_is_realview_eb_mp())
@@ -50,20 +62,10 @@ static void __iomem *scu_base_addr(void)
 		return (void __iomem *)0;
 }
 
-static inline unsigned int get_core_count(void)
-{
-	void __iomem *scu_base = scu_base_addr();
-	if (scu_base)
-		return scu_get_core_count(scu_base);
-	return 1;
-}
-
 static DEFINE_SPINLOCK(boot_lock);
 
 void __cpuinit platform_secondary_init(unsigned int cpu)
 {
-	trace_hardirqs_off();
-
 	/*
 	 * if any interrupts are already enabled for the primary
 	 * core (e.g. timer irq), then they will not have been enabled
@@ -75,8 +77,7 @@ void __cpuinit platform_secondary_init(unsigned int cpu)
 	 * let the primary processor know we're out of the
 	 * pen, then head off into the C entry point
 	 */
-	pen_release = -1;
-	smp_wmb();
+	write_pen_release(-1);
 
 	/*
 	 * Synchronise with the boot thread.
@@ -103,20 +104,14 @@ int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
 	 * Note that "pen_release" is the hardware CPU ID, whereas
 	 * "cpu" is Linux's internal ID.
 	 */
-	pen_release = cpu;
-	flush_cache_all();
+	write_pen_release(cpu);
 
 	/*
-	 * XXX
-	 *
-	 * This is a later addition to the booting protocol: the
-	 * bootMonitor now puts secondary cores into WFI, so
-	 * poke_milo() no longer gets the cores moving; we need
-	 * to send a soft interrupt to wake the secondary core.
-	 * Use smp_cross_call() for this, since there's little
-	 * point duplicating the code here
+	 * Send the secondary CPU a soft interrupt, thereby causing
+	 * the boot monitor to read the system wide flags register,
+	 * and branch to the address found there.
 	 */
-	smp_cross_call(cpumask_of(cpu));
+	smp_cross_call(cpumask_of(cpu), 1);
 
 	timeout = jiffies + (1 * HZ);
 	while (time_before(jiffies, timeout)) {
@@ -136,48 +131,18 @@ int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
 	return pen_release != -1 ? -ENOSYS : 0;
 }
 
-static void __init poke_milo(void)
-{
-	/* nobody is to be released from the pen yet */
-	pen_release = -1;
-
-	/*
-	 * Write the address of secondary startup into the system-wide flags
-	 * register. The BootMonitor waits for this register to become
-	 * non-zero.
-	 */
-	__raw_writel(BSYM(virt_to_phys(realview_secondary_startup)),
-		     __io_address(REALVIEW_SYS_FLAGSSET));
-
-	mb();
-}
-
 /*
  * Initialise the CPU possible map early - this describes the CPUs
  * which may be present or become present in the system.
  */
 void __init smp_init_cpus(void)
 {
-	unsigned int i, ncores = get_core_count();
+	void __iomem *scu_base = scu_base_addr();
+	unsigned int i, ncores;
 
-	for (i = 0; i < ncores; i++)
-		set_cpu_possible(i, true);
-}
-
-void __init smp_prepare_cpus(unsigned int max_cpus)
-{
-	unsigned int ncores = get_core_count();
-	unsigned int cpu = smp_processor_id();
-	int i;
+	ncores = scu_base ? scu_get_core_count(scu_base) : 1;
 
 	/* sanity check */
-	if (ncores == 0) {
-		printk(KERN_ERR
-		       "Realview: strange CM count of 0? Default to 1\n");
-
-		ncores = 1;
-	}
-
 	if (ncores > NR_CPUS) {
 		printk(KERN_WARNING
 		       "Realview: no. of cores (%d) greater than configured "
@@ -186,13 +151,13 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 		ncores = NR_CPUS;
 	}
 
-	smp_store_cpu_info(cpu);
+	for (i = 0; i < ncores; i++)
+		set_cpu_possible(i, true);
+}
 
-	/*
-	 * are we trying to boot more cores than exist?
-	 */
-	if (max_cpus > ncores)
-		max_cpus = ncores;
+void __init platform_smp_prepare_cpus(unsigned int max_cpus)
+{
+	int i;
 
 	/*
 	 * Initialise the present map, which describes the set of CPUs
@@ -201,21 +166,14 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 	for (i = 0; i < max_cpus; i++)
 		set_cpu_present(i, true);
 
+	scu_enable(scu_base_addr());
+
 	/*
-	 * Initialise the SCU if there are more than one CPU and let
-	 * them know where to start. Note that, on modern versions of
-	 * MILO, the "poke" doesn't actually do anything until each
-	 * individual core is sent a soft interrupt to get it out of
-	 * WFI
+	 * Write the address of secondary startup into the
+	 * system-wide flags register. The BootMonitor waits
+	 * until it receives a soft interrupt, and then the
+	 * secondary CPU branches to this address.
 	 */
-	if (max_cpus > 1) {
-		/*
-		 * Enable the local timer or broadcast device for the
-		 * boot CPU, but only if we have more than one CPU.
-		 */
-		percpu_timer_setup();
-
-		scu_enable(scu_base_addr());
-		poke_milo();
-	}
+	__raw_writel(BSYM(virt_to_phys(realview_secondary_startup)),
+		     __io_address(REALVIEW_SYS_FLAGSSET));
 }