arm64: Remove boot thread synchronisation for spin-table release method

The synchronisation with the boot thread already happens in __cpu_up()
via wait_for_completion_timeout(). In addition, __cpu_up() calls are
protected by the cpu_add_remove_lock mutex and already serialised.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/kernel/smp_spin_table.c b/arch/arm64/kernel/smp_spin_table.c
index 7a530d2..0347d38 100644 (file)
--- a/arch/arm64/kernel/smp_spin_table.c
+++ b/arch/arm64/kernel/smp_spin_table.c
@@ -30,7 +30,6 @@ extern void secondary_holding_pen(void);
 volatile unsigned long secondary_holding_pen_release = INVALID_HWID;
 
 static phys_addr_t cpu_release_addr[NR_CPUS];
-static DEFINE_RAW_SPINLOCK(boot_lock);
 
 /*
  * Write secondary_holding_pen_release in a way that is guaranteed to be
@@ -94,14 +93,6 @@ static int smp_spin_table_cpu_prepare(unsigned int cpu)
 
 static int smp_spin_table_cpu_boot(unsigned int cpu)
 {
-       unsigned long timeout;
-
-       /*
-        * Set synchronisation state between this boot processor
-        * and the secondary one
-        */
-       raw_spin_lock(&boot_lock);
-
        /*
         * Update the pen release flag.
         */
@@ -112,34 +103,7 @@ static int smp_spin_table_cpu_boot(unsigned int cpu)
         */
        sev();
 
-       timeout = jiffies + (1 * HZ);
-       while (time_before(jiffies, timeout)) {
-               if (secondary_holding_pen_release == INVALID_HWID)
-                       break;
-               udelay(10);
-       }
-
-       /*
-        * Now the secondary core is starting up let it run its
-        * calibrations, then wait for it to finish
-        */
-       raw_spin_unlock(&boot_lock);
-
-       return secondary_holding_pen_release != INVALID_HWID ? -ENOSYS : 0;
-}
-
-static void smp_spin_table_cpu_postboot(void)
-{
-       /*
-        * Let the primary processor know we're out of the pen.
-        */
-       write_pen_release(INVALID_HWID);
-
-       /*
-        * Synchronise with the boot thread.
-        */
-       raw_spin_lock(&boot_lock);
-       raw_spin_unlock(&boot_lock);
+       return 0;
 }
 
 const struct cpu_operations smp_spin_table_ops = {
@@ -147,5 +111,4 @@ const struct cpu_operations smp_spin_table_ops = {
        .cpu_init       = smp_spin_table_cpu_init,
        .cpu_prepare    = smp_spin_table_cpu_prepare,
        .cpu_boot       = smp_spin_table_cpu_boot,
-       .cpu_postboot   = smp_spin_table_cpu_postboot,
 };