powerpc/e6500: kexec: Handle hardware threads

The new kernel will be expecting secondary threads to be disabled,
not spinning.

Signed-off-by: Scott Wood <scottwood@freescale.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c
index 2e4668435307..712764f3dcbc 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -374,9 +374,55 @@ static void mpc85xx_smp_kexec_down(void *arg)
 #else
 void mpc85xx_smp_kexec_cpu_down(int crash_shutdown, int secondary)
 {
+	int cpu = smp_processor_id();
+	int sibling = cpu_last_thread_sibling(cpu);
+	bool notified = false;
+	int disable_cpu;
+	int disable_threadbit = 0;
+	long start = mftb();
+	long now;
+
 	local_irq_disable();
 	hard_irq_disable();
 	mpic_teardown_this_cpu(secondary);
+
+	if (cpu == crashing_cpu && cpu_thread_in_core(cpu) != 0) {
+		/*
+		 * We enter the crash kernel on whatever cpu crashed,
+		 * even if it's a secondary thread.  If that's the case,
+		 * disable the corresponding primary thread.
+		 */
+		disable_threadbit = 1;
+		disable_cpu = cpu_first_thread_sibling(cpu);
+	} else if (sibling != crashing_cpu &&
+		   cpu_thread_in_core(cpu) == 0 &&
+		   cpu_thread_in_core(sibling) != 0) {
+		disable_threadbit = 2;
+		disable_cpu = sibling;
+	}
+
+	if (disable_threadbit) {
+		while (paca[disable_cpu].kexec_state < KEXEC_STATE_REAL_MODE) {
+			barrier();
+			now = mftb();
+			if (!notified && now - start > 1000000) {
+				pr_info("%s/%d: waiting for cpu %d to enter KEXEC_STATE_REAL_MODE (%d)\n",
+					__func__, smp_processor_id(),
+					disable_cpu,
+					paca[disable_cpu].kexec_state);
+				notified = true;
+			}
+		}
+
+		if (notified) {
+			pr_info("%s: cpu %d done waiting\n",
+				__func__, disable_cpu);
+		}
+
+		mtspr(SPRN_TENC, disable_threadbit);
+		while (mfspr(SPRN_TENSR) & disable_threadbit)
+			cpu_relax();
+	}
 }
 #endif