Merge branch 'linux-3.10.y' of git://git.kernel.org/pub/scm/linux/kernel/git/stable...

[firefly-linux-kernel-4.4.55.git] / arch / arm64 / kernel / smp.c

diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 7c868a2ac38b23ed03a919c70ef1f2b7e1e8c6b6..9a3c7ef182fd773420df468daa1a25532d80391e 100644 (file)
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -162,6 +162,11 @@ asmlinkage void __cpuinit secondary_start_kernel(void)
 
        smp_store_cpu_info(cpu);
 
+       /*
+        * Log the CPU info before it is marked online and might get read.
+        */
+       cpuinfo_store_cpu();
+
        /*
         * OK, now it's safe to let the boot CPU continue.  Wait for
         * the CPU migration code to notice that the CPU is online
@@ -231,6 +236,19 @@ int __cpu_disable(void)
        return 0;
 }
 
+static int op_cpu_kill(unsigned int cpu)
+{
+       /*
+        * If we have no means of synchronising with the dying CPU, then assume
+        * that it is really dead. We can only wait for an arbitrary length of
+        * time and hope that it's dead, so let's skip the wait and just hope.
+        */
+       if (!cpu_ops[cpu]->cpu_kill)
+               return 1;
+
+       return cpu_ops[cpu]->cpu_kill(cpu);
+}
+
 static DECLARE_COMPLETION(cpu_died);
 
 /*
@@ -244,6 +262,15 @@ void __cpu_die(unsigned int cpu)
                return;
        }
        pr_notice("CPU%u: shutdown\n", cpu);
+
+       /*
+        * Now that the dying CPU is beyond the point of no return w.r.t.
+        * in-kernel synchronisation, try to get the firwmare to help us to
+        * verify that it has really left the kernel before we consider
+        * clobbering anything it might still be using.
+        */
+       if (!op_cpu_kill(cpu))
+               pr_warn("CPU%d may not have shut down cleanly\n", cpu);
 }
 
 /*