x86, lib: Add wbinvd smp helpers

Add wbinvd_on_cpu and wbinvd_on_all_cpus stubs for executing wbinvd on a
particular CPU.

[ hpa: renamed lib/smp.c to lib/cache-smp.c ]
[ hpa: wbinvd_on_all_cpus() returns int, but wbinvd() returns
  void.  Thus, the former cannot be a macro for the latter,
  replace with an inline function. ]

Signed-off-by: Borislav Petkov <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>

1 files changed, 19 insertions, 0 deletions

diff --git a/arch/x86/lib/cache-smp.c b/arch/x86/lib/cache-smp.c
new file mode 100644
index 000000000000..a3c668875038
--- /dev/null
+++ b/arch/x86/lib/cache-smp.c
@@ -0,0 +1,19 @@
+#include <linux/smp.h>
+#include <linux/module.h>
+
+static void __wbinvd(void *dummy)
+{
+	wbinvd();
+}
+
+void wbinvd_on_cpu(int cpu)
+{
+	smp_call_function_single(cpu, __wbinvd, NULL, 1);
+}
+EXPORT_SYMBOL(wbinvd_on_cpu);
+
+int wbinvd_on_all_cpus(void)
+{
+	return on_each_cpu(__wbinvd, NULL, 1);
+}
+EXPORT_SYMBOL(wbinvd_on_all_cpus);