[PATCH 075/139] powerpc/kexec: Disable hard IRQ before kexec

[Luis Henriques]

3.5.7.7 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Phileas Fogg <phileas-fogg@xxxxxxx>

commit 8520e443aa56cc157b015205ea53e7b9fc831291 upstream.

Disable hard IRQ before kexec a new kernel image.
Not doing it can result in corrupted data in the memory segments
reserved for the new kernel.

Signed-off-by: Phileas Fogg <phileas-fogg@xxxxxxx>
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Luis Henriques <luis.henriques@xxxxxxxxxxxxx>
---
 arch/powerpc/kernel/machine_kexec_64.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/powerpc/kernel/machine_kexec_64.c b/arch/powerpc/kernel/machine_kexec_64.c
index d7f6090..39833e0 100644
--- a/arch/powerpc/kernel/machine_kexec_64.c
+++ b/arch/powerpc/kernel/machine_kexec_64.c
@@ -162,6 +162,8 @@ static int kexec_all_irq_disabled = 0;
 static void kexec_smp_down(void *arg)
 {
 	local_irq_disable();
+	hard_irq_disable();
+
 	mb(); /* make sure our irqs are disabled before we say they are */
 	get_paca()->kexec_state = KEXEC_STATE_IRQS_OFF;
 	while(kexec_all_irq_disabled == 0)
@@ -244,6 +246,8 @@ static void kexec_prepare_cpus(void)
 	wake_offline_cpus();
 	smp_call_function(kexec_smp_down, NULL, /* wait */0);
 	local_irq_disable();
+	hard_irq_disable();
+
 	mb(); /* make sure IRQs are disabled before we say they are */
 	get_paca()->kexec_state = KEXEC_STATE_IRQS_OFF;
 
@@ -281,6 +285,7 @@ static void kexec_prepare_cpus(void)
 	if (ppc_md.kexec_cpu_down)
 		ppc_md.kexec_cpu_down(0, 0);
 	local_irq_disable();
+	hard_irq_disable();
 }
 
 #endif /* SMP */
-- 
1.8.1.2

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