1 files changed, 26 insertions, 48 deletions

diff --git a/arch/arm/mach-vexpress/platsmp.c b/arch/arm/mach-vexpress/platsmp.c
index dfb591031d17..b1687b6abe63 100644
--- a/arch/arm/mach-vexpress/platsmp.c
+++ b/arch/arm/mach-vexpress/platsmp.c
@@ -17,7 +17,6 @@
 #include <linux/io.h>
 
 #include <asm/cacheflush.h>
-#include <asm/localtimer.h>
 #include <asm/smp_scu.h>
 #include <asm/unified.h>
 
@@ -35,6 +34,19 @@ extern void vexpress_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)
 {
         return MMIO_P2V(A9_MPCORE_SCU);
@@ -44,8 +56,6 @@ 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
@@ -57,8 +67,7 @@ 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.
@@ -83,16 +92,14 @@ int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
          * since we haven't sent them a soft interrupt, they shouldn't
          * be there.
          */
-        pen_release = cpu;
-        __cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release));
-        outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));
+        write_pen_release(cpu);
 
         /*
          * 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)) {
@@ -124,13 +131,6 @@ void __init smp_init_cpus(void)
         ncores = scu_base ? scu_get_core_count(scu_base) : 1;
 
         /* sanity check */
-        if (ncores == 0) {
-                printk(KERN_ERR
-                       "vexpress: strange CM count of 0? Default to 1\n");
-
-                ncores = 1;
-        }
-
         if (ncores > NR_CPUS) {
                 printk(KERN_WARNING
                        "vexpress: no. of cores (%d) greater than configured "
@@ -143,20 +143,10 @@ void __init smp_init_cpus(void)
                 set_cpu_possible(i, true);
 }
 
-void __init smp_prepare_cpus(unsigned int max_cpus)
+void __init platform_smp_prepare_cpus(unsigned int max_cpus)
 {
-        unsigned int ncores = num_possible_cpus();
-        unsigned int cpu = smp_processor_id();
         int i;
 
-        smp_store_cpu_info(cpu);
-
-        /*
-         * are we trying to boot more cores than exist?
-         */
-        if (max_cpus > ncores)
-                max_cpus = ncores;
-
         /*
          * Initialise the present map, which describes the set of CPUs
          * actually populated at the present time.
@@ -164,27 +154,15 @@ 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.
+         * Write the address of secondary startup into the
+         * system-wide flags register. The boot monitor 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());
-
-                /*
-                 * Write the address of secondary startup into the
-                 * system-wide flags register. The boot monitor waits
-                 * until it receives a soft interrupt, and then the
-                 * secondary CPU branches to this address.
-                 */
-                writel(~0, MMIO_P2V(V2M_SYS_FLAGSCLR));
-                writel(BSYM(virt_to_phys(vexpress_secondary_startup)),
-                        MMIO_P2V(V2M_SYS_FLAGSSET));
-        }
+        writel(~0, MMIO_P2V(V2M_SYS_FLAGSCLR));
+        writel(BSYM(virt_to_phys(vexpress_secondary_startup)),
+                MMIO_P2V(V2M_SYS_FLAGSSET));
 }