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Diffstat (limited to 'arch/arm/mach-ux500/platsmp.c')
-rw-r--r--arch/arm/mach-ux500/platsmp.c73
1 files changed, 26 insertions, 47 deletions
diff --git a/arch/arm/mach-ux500/platsmp.c b/arch/arm/mach-ux500/platsmp.c
index b5077b4c419f..2115a0cf07b0 100644
--- a/arch/arm/mach-ux500/platsmp.c
+++ b/arch/arm/mach-ux500/platsmp.c
@@ -18,7 +18,6 @@
#include <linux/io.h>
#include <asm/cacheflush.h>
-#include <asm/localtimer.h>
#include <asm/smp_scu.h>
#include <mach/hardware.h>
@@ -28,17 +27,23 @@
*/
volatile int __cpuinitdata pen_release = -1;
-static unsigned int __init get_core_count(void)
+/*
+ * 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)
{
- return scu_get_core_count(__io_address(UX500_SCU_BASE));
+ 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 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
@@ -50,7 +55,7 @@ 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;
+ write_pen_release(-1);
/*
* Synchronise with the boot thread.
@@ -74,11 +79,9 @@ int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
* the holding pen - release it, then wait for it to flag
* that it has been released by resetting pen_release.
*/
- 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);
- smp_cross_call(cpumask_of(cpu));
+ smp_cross_call(cpumask_of(cpu), 1);
timeout = jiffies + (1 * HZ);
while (time_before(jiffies, timeout)) {
@@ -97,9 +100,6 @@ int __cpuinit boot_secondary(unsigned int cpu, struct task_struct *idle)
static void __init wakeup_secondary(void)
{
- /* nobody is to be released from the pen yet */
- pen_release = -1;
-
/*
* write the address of secondary startup into the backup ram register
* at offset 0x1FF4, then write the magic number 0xA1FEED01 to the
@@ -126,40 +126,26 @@ static void __init wakeup_secondary(void)
*/
void __init smp_init_cpus(void)
{
- unsigned int i, ncores = get_core_count();
+ 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_get_core_count(__io_address(UX500_SCU_BASE));
/* sanity check */
- if (ncores == 0) {
- printk(KERN_ERR
- "U8500: strange CM count of 0? Default to 1\n");
- ncores = 1;
- }
-
- if (ncores > num_possible_cpus()) {
+ if (ncores > NR_CPUS) {
printk(KERN_WARNING
"U8500: no. of cores (%d) greater than configured "
"maximum of %d - clipping\n",
- ncores, num_possible_cpus());
- ncores = num_possible_cpus();
+ ncores, NR_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
@@ -168,13 +154,6 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
for (i = 0; i < max_cpus; i++)
set_cpu_present(i, true);
- 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(__io_address(UX500_SCU_BASE));
- wakeup_secondary();
- }
+ scu_enable(__io_address(UX500_SCU_BASE));
+ wakeup_secondary();
}