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authorJisheng Zhang <jszhang@marvell.com>2015-09-14 14:47:45 +0800
committerSebastian Hesselbarth <sebastian.hesselbarth@gmail.com>2015-10-15 21:14:28 +0200
commita7b3d5a715f489ee542e59d722281c9f16da50dc (patch)
tree11d08feb2a78ecd1f6306b73c6cf21fe83398b01 /arch/arm/mach-berlin
parentac7fc233b2c337880d7d973be19f6fb03108d6f7 (diff)
arm: berlin: add CPU hotplug support
Add cpu hotplug support for berlin SoCs such as BG2 and BG2Q. These SoC don't support power off cpu independently, but we also want cpu hotplug support in these SoCs. We achieve this goal by putting the dying CPU in WFI state after the coherency is disabled, then asserting the dying CPU reset bit to put the CPU in reset state. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Diffstat (limited to 'arch/arm/mach-berlin')
-rw-r--r--arch/arm/mach-berlin/platsmp.c25
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/arm/mach-berlin/platsmp.c b/arch/arm/mach-berlin/platsmp.c
index 64cb1ab182c4..405cd37e4fba 100644
--- a/arch/arm/mach-berlin/platsmp.c
+++ b/arch/arm/mach-berlin/platsmp.c
@@ -14,6 +14,7 @@
#include <linux/of_address.h>
#include <asm/cacheflush.h>
+#include <asm/cp15.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
@@ -98,8 +99,32 @@ unmap_scu:
iounmap(scu_base);
}
+#ifdef CONFIG_HOTPLUG_CPU
+static void berlin_cpu_die(unsigned int cpu)
+{
+ v7_exit_coherency_flush(louis);
+ while (1)
+ cpu_do_idle();
+}
+
+static int berlin_cpu_kill(unsigned int cpu)
+{
+ u32 val;
+
+ val = readl(cpu_ctrl + CPU_RESET_NON_SC);
+ val &= ~BIT(cpu_logical_map(cpu));
+ writel(val, cpu_ctrl + CPU_RESET_NON_SC);
+
+ return 1;
+}
+#endif
+
static struct smp_operations berlin_smp_ops __initdata = {
.smp_prepare_cpus = berlin_smp_prepare_cpus,
.smp_boot_secondary = berlin_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+ .cpu_die = berlin_cpu_die,
+ .cpu_kill = berlin_cpu_kill,
+#endif
};
CPU_METHOD_OF_DECLARE(berlin_smp, "marvell,berlin-smp", &berlin_smp_ops);