diff options
Diffstat (limited to 'arch/arm/mach-spear/platsmp.c')
-rw-r--r-- | arch/arm/mach-spear/platsmp.c | 21 |
1 files changed, 15 insertions, 6 deletions
diff --git a/arch/arm/mach-spear/platsmp.c b/arch/arm/mach-spear/platsmp.c index 5c4a19887b2b..fd4297713d67 100644 --- a/arch/arm/mach-spear/platsmp.c +++ b/arch/arm/mach-spear/platsmp.c @@ -4,7 +4,7 @@ * based upon linux/arch/arm/mach-realview/platsmp.c * * Copyright (C) 2012 ST Microelectronics Ltd. - * Shiraz Hashim <shiraz.hashim@st.com> + * Shiraz Hashim <shiraz.linux.kernel@gmail.com> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -20,6 +20,18 @@ #include <mach/spear.h> #include "generic.h" +/* + * 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(); + sync_cache_w(&pen_release); +} + static DEFINE_SPINLOCK(boot_lock); static void __iomem *scu_base = IOMEM(VA_SCU_BASE); @@ -30,8 +42,7 @@ static void spear13xx_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. @@ -58,9 +69,7 @@ static int spear13xx_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(); - outer_flush_all(); + write_pen_release(cpu); timeout = jiffies + (1 * HZ); while (time_before(jiffies, timeout)) { |