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authorLorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>2014-01-24 10:56:19 +0000
committerAlex Shi <alex.shi@linaro.org>2014-03-10 13:38:37 +0800
commitb7ce906de4a27a21c1ac7b89baa513edf1d1600e (patch)
parent0be1f6174d684a162051e22f1fb7e4be1f77be4e (diff)
arm64: kernel: fix per-cpu offset restore on resume
The introduction of percpu offset optimisation through tpidr_el1 in: Commit id :7158627686f02319c50c8d9d78f75d4c8 "arm64: percpu: implement optimised pcpu access using tpidr_el1" requires cpu_{suspend/resume} to restore the tpidr_el1 register upon resume so that percpu variables can be addressed correctly when a CPU comes out of reset from warm-boot. This patch fixes cpu_{suspend}/{resume} tpidr_el1 restoration on resume, by calling the set_my_cpu_offset C API, as it is done on primary and secondary CPUs on cold boot, so that, even if the register used to store the percpu offset is changed, the save and restore of general purpose registers does not have to be updated. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c
index 430344e2c989..1fa9ce4afd8f 100644
--- a/arch/arm64/kernel/suspend.c
+++ b/arch/arm64/kernel/suspend.c
@@ -1,3 +1,4 @@
+#include <linux/percpu.h>
#include <linux/slab.h>
#include <asm/cacheflush.h>
#include <asm/cpu_ops.h>
@@ -89,6 +90,13 @@ int cpu_suspend(unsigned long arg)
if (ret == 0) {
cpu_switch_mm(mm->pgd, mm);
+ /*
+ * Restore per-cpu offset before any kernel
+ * subsystem relying on it has a chance to run.
+ */
+ set_my_cpu_offset(per_cpu_offset(cpu));
* Restore HW breakpoint registers to sane values
* before debug exceptions are possibly reenabled