irqchip/gic: Warn if GICv3 system registers are enabled
When using a GICv3 in compatibility (v2) mode, having GICv3 system
register access enabled is not really compliant with the architecture.
Warn if the firmware (or the hypervisor) has been lazy.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index d0ce7ed..a9f23cf 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -51,6 +51,19 @@
#include "irq-gic-common.h"
+#ifdef CONFIG_ARM64
+#include <asm/cpufeature.h>
+
+static void gic_check_cpu_features(void)
+{
+ WARN_TAINT_ONCE(cpus_have_cap(ARM64_HAS_SYSREG_GIC_CPUIF),
+ TAINT_CPU_OUT_OF_SPEC,
+ "GICv3 system registers enabled, broken firmware!\n");
+}
+#else
+#define gic_check_cpu_features() do { } while(0)
+#endif
+
union gic_base {
void __iomem *common_base;
void __percpu * __iomem *percpu_base;
@@ -987,6 +1000,8 @@
BUG_ON(gic_nr >= MAX_GIC_NR);
+ gic_check_cpu_features();
+
gic = &gic_data[gic_nr];
#ifdef CONFIG_GIC_NON_BANKED
if (percpu_offset) { /* Frankein-GIC without banked registers... */
