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authorAshwin Chaugule <ashwin.chaugule@linaro.org>2014-03-27 17:23:50 -0400
committerGraeme Gregory <graeme.gregory@linaro.org>2014-06-03 09:24:18 +0100
commit4ca6e1651e98b0c373e5d678099c990db13ed4b0 (patch)
treebc11fae8b22f96dfe49b88f4e32f0eaf696fd266
parent609e2b1a1125762026c19b09e8b3a5ef35689f8e (diff)
downloadleg-kernel-4ca6e1651e98b0c373e5d678099c990db13ed4b0.tar.gz
ARM: Check if a CPU has gone offline
PSCIv0.2 adds a new function called AFFINITY_INFO, which can be used to query if a specified CPU has actually gone offline. Calling this function via cpu_kill ensures that a CPU has quiesced after a call to cpu_die. Signed-off-by: Ashwin Chaugule <ashwin.chaugule@linaro.org>
-rw-r--r--arch/arm/kernel/psci_smp.c21
-rw-r--r--include/uapi/linux/psci.h5
2 files changed, 26 insertions, 0 deletions
diff --git a/arch/arm/kernel/psci_smp.c b/arch/arm/kernel/psci_smp.c
index 570a48cc3d64..4c1adf9aa380 100644
--- a/arch/arm/kernel/psci_smp.c
+++ b/arch/arm/kernel/psci_smp.c
@@ -16,6 +16,7 @@
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/of.h>
+#include <uapi/linux/psci.h>
#include <asm/psci.h>
#include <asm/smp_plat.h>
@@ -66,6 +67,25 @@ void __ref psci_cpu_die(unsigned int cpu)
/* We should never return */
panic("psci: cpu %d failed to shutdown\n", cpu);
}
+
+int __ref psci_cpu_kill(unsigned int cpu)
+{
+ int err;
+
+ if (!psci_ops.affinity_info)
+ return 1;
+
+ err = psci_ops.affinity_info(cpu_logical_map(cpu), 0);
+
+ if (err != PSCI_AFFINITY_INFO_RET_OFF) {
+ pr_err("psci: Cannot kill CPU:%d, psci ret val: %d\n",
+ cpu, err);
+ /* Make platform_cpu_kill() fail. */
+ return 0;
+ }
+ return err;
+}
+
#endif
bool __init psci_smp_available(void)
@@ -78,5 +98,6 @@ struct smp_operations __initdata psci_smp_ops = {
.smp_boot_secondary = psci_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = psci_cpu_die,
+ .cpu_kill = psci_cpu_kill,
#endif
};
diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
index c5230511e25a..2c177f58ce14 100644
--- a/include/uapi/linux/psci.h
+++ b/include/uapi/linux/psci.h
@@ -37,4 +37,9 @@
#define PSCI_RET_EINVAL -2
#define PSCI_RET_EPERM -3
+/* Return values from the PSCI_ID_AFFINITY_INFO Function. */
+#define PSCI_AFFINITY_INFO_RET_ON 0
+#define PSCI_AFFINITY_INFO_RET_OFF 1
+#define PSCI_AFFINITY_INFO_RET_ON_PENDING 2
+
#endif /* _UAPI_LINUX_PSCI_H */