Commit-ID:  ddd07b750382adc2b78fdfbec47af8a6e0d8ef37
Gitweb:     https://git.kernel.org/tip/ddd07b750382adc2b78fdfbec47af8a6e0d8ef37
Author:     Peter Zijlstra <pet...@infradead.org>
AuthorDate: Wed, 19 Sep 2018 10:50:19 +0200
Committer:  Thomas Gleixner <t...@linutronix.de>
CommitDate: Thu, 27 Sep 2018 20:39:41 +0200

x86/mm/cpa: Unconditionally avoid WBINDV when we can

CAT has happened, WBINDV is bad (even before CAT blowing away the
entire cache on a multi-core platform wasn't nice), try not to use it
ever.

Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Reviewed-by: Dave Hansen <dave.han...@intel.com>
Cc: Bin Yang <bin.y...@intel.com>
Cc: Mark Gross <mark.gr...@intel.com>
Link: https://lkml.kernel.org/r/20180919085947.933674...@infradead.org

---
 arch/x86/mm/pageattr.c | 18 ++----------------
 1 file changed, 2 insertions(+), 16 deletions(-)

diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index b6a4c638f086..bd9b0ac07352 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -319,26 +319,12 @@ static void cpa_flush_array(unsigned long *start, int 
numpages, int cache,
                            int in_flags, struct page **pages)
 {
        unsigned int i, level;
-#ifdef CONFIG_PREEMPT
-       /*
-        * Avoid wbinvd() because it causes latencies on all CPUs,
-        * regardless of any CPU isolation that may be in effect.
-        *
-        * This should be extended for CAT enabled systems independent of
-        * PREEMPT because wbinvd() does not respect the CAT partitions and
-        * this is exposed to unpriviledged users through the graphics
-        * subsystem.
-        */
-       unsigned long do_wbinvd = 0;
-#else
-       unsigned long do_wbinvd = cache && numpages >= 1024; /* 4M threshold */
-#endif
 
        BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);
 
-       on_each_cpu(__cpa_flush_all, (void *) do_wbinvd, 1);
+       flush_tlb_all();
 
-       if (!cache || do_wbinvd)
+       if (!cache)
                return;
 
        /*

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