x86: work around Fedora-11 x86-32 kernel failures on Intel Atom CPUs
Impact: work around boot crash
Work around Intel Atom erratum AAH41 (probabilistically) - it's triggering
in the field.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Kyle McMartin <kyle@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 7be47d1..7233bd7 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -515,6 +515,17 @@
* primary protection behavior:
*/
__set_pmd_pte(kpte, address, mk_pte(base, __pgprot(_KERNPG_TABLE)));
+
+ /*
+ * Intel Atom errata AAH41 workaround.
+ *
+ * The real fix should be in hw or in a microcode update, but
+ * we also probabilistically try to reduce the window of having
+ * a large TLB mixed with 4K TLBs while instruction fetches are
+ * going on.
+ */
+ __flush_tlb_all();
+
base = NULL;
out_unlock: