[SRU Xenial, Yakkety][PATCH 1/3] crypto: vmx - comply with ABIs that specify vrsave as reserved.

[Kamal Mostafa]

From: Paulo Flabiano Smorigo <pfsmorigo at linux.vnet.ibm.com>

BugLink: http://bugs.launchpad.net/bugs/1592481

It gives significant improvements ( ~+15%) on some modes.

These code has been adopted from OpenSSL project in collaboration
with the original author (Andy Polyakov <appro at openssl.org>).

Signed-off-by: Paulo Flabiano Smorigo <pfsmorigo at linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert at gondor.apana.org.au>
(cherry picked from commit 5ca55738201c7ae1b556ad87bbb22c139ecc01dd)
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/crypto/vmx/ppc-xlate.pl | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/drivers/crypto/vmx/ppc-xlate.pl b/drivers/crypto/vmx/ppc-xlate.pl
index b999733..9f4994c 100644
--- a/drivers/crypto/vmx/ppc-xlate.pl
+++ b/drivers/crypto/vmx/ppc-xlate.pl
@@ -139,6 +139,26 @@ my $vmr = sub {
     "	vor	$vx,$vy,$vy";
 };
 
+# Some ABIs specify vrsave, special-purpose register #256, as reserved
+# for system use.
+my $no_vrsave = ($flavour =~ /aix|linux64le/);
+my $mtspr = sub {
+    my ($f,$idx,$ra) = @_;
+    if ($idx == 256 && $no_vrsave) {
+	"	or	$ra,$ra,$ra";
+    } else {
+	"	mtspr	$idx,$ra";
+    }
+};
+my $mfspr = sub {
+    my ($f,$rd,$idx) = @_;
+    if ($idx == 256 && $no_vrsave) {
+	"	li	$rd,-1";
+    } else {
+	"	mfspr	$rd,$idx";
+    }
+};
+
 # PowerISA 2.06 stuff
 sub vsxmem_op {
     my ($f, $vrt, $ra, $rb, $op) = @_;
-- 
2.7.4