ARM: 8488/1: Make IPI_CPU_BACKTRACE a "non-secure" SGI
Having IPI_CPU_BACKTRACE as SGI15 may not work if the kernel is
running in non-secure mode and that the secure firmware has
decided to follow ARM's recommendations that SGI8-15 should
be reserved for secure purpose.
Now that we are "only" using SGI0-6, change IPI_CPU_BACKTRACE
to use SGI7, which makes it more likely to work.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index d50a77d..37312f6 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -72,7 +72,12 @@
IPI_CPU_STOP,
IPI_IRQ_WORK,
IPI_COMPLETION,
- IPI_CPU_BACKTRACE = 15,
+ IPI_CPU_BACKTRACE,
+ /*
+ * SGI8-15 can be reserved by secure firmware, and thus may
+ * not be usable by the kernel. Please keep the above limited
+ * to at most 8 entries.
+ */
};
static DECLARE_COMPLETION(cpu_running);