x86: cpa_flush_array wbinvd should be done on all CPUs

cpa_flush_array seems to prefer wbinvd() over clflush at 4M threshold.
clflush needs to be done on only one CPU as per instruction definition.
wbinvd() however, should be done on all CPUs.

[ Impact: fix missing flush which could cause data corruption ]

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 2cc019a3f71b..0f9052bcec4b 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -204,6 +204,11 @@ static void cpa_flush_range(unsigned long start, int numpages, int cache)
         }
 }
 
+static void wbinvd_local(void *unused)
+{
+        wbinvd();
+}
+
 static void cpa_flush_array(unsigned long *start, int numpages, int cache,
                             int in_flags, struct page **pages)
 {
@@ -219,7 +224,8 @@ static void cpa_flush_array(unsigned long *start, int numpages, int cache,
         /* 4M threshold */
         if (numpages >= 1024) {
                 if (boot_cpu_data.x86 >= 4)
-                        wbinvd();
+                        on_each_cpu(wbinvd_local, NULL, 1);
+
                 return;
         }
         /*