xen/cpu: Fix ARM build following c/s 597fbb8

c/s 597fbb8 "xen/timers: Fix memory leak with cpu unplug/plug" broke the ARM
build by being the first patch to add park_offline_cpus to common code.

While it is currently specific to Intel hardware (for reasons of being able to
handle machine check exceptions without an immediate system reset), it isn't
inherently architecture specific, so define it to be false on ARM for now.

Add a comment in both smp.h headers explaining the intended behaviour of the
option.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>

diff --git a/xen/include/asm-arm/smp.h b/xen/include/asm-arm/smp.h
index 3c122681d7625c07db12f88a6a8eb416b9221810..fdbcefa2412153c64e7970bd5b7ddc05794c6cb8 100644 (file)
--- a/xen/include/asm-arm/smp.h
+++ b/xen/include/asm-arm/smp.h
@@ -14,6 +14,12 @@ DECLARE_PER_CPU(cpumask_var_t, cpu_core_mask);
 
 #define raw_smp_processor_id() (get_processor_id())
 
+/*
+ * Do we, for platform reasons, need to actually keep CPUs online when we
+ * would otherwise prefer them to be off?
+ */
+#define park_offline_cpus false
+
 extern void noreturn stop_cpu(void);
 
 extern int arch_smp_init(void);

diff --git a/xen/include/asm-x86/smp.h b/xen/include/asm-x86/smp.h
index 09c55458df9b1fb76d27de3c22a173e9d4577810..9f533f90722714b08ff0b0f0b898041ad6254cf7 100644 (file)
--- a/xen/include/asm-x86/smp.h
+++ b/xen/include/asm-x86/smp.h
@@ -26,6 +26,10 @@ DECLARE_PER_CPU(cpumask_var_t, cpu_sibling_mask);
 DECLARE_PER_CPU(cpumask_var_t, cpu_core_mask);
 DECLARE_PER_CPU(cpumask_var_t, scratch_cpumask);
 
+/*
+ * Do we, for platform reasons, need to actually keep CPUs online when we
+ * would otherwise prefer them to be off?
+ */
 extern bool park_offline_cpus;
 
 void smp_send_nmi_allbutself(void);