pseries: Add H_SET_MODE to change exception endianness
On little endian builds call H_SET_MODE so exceptions have the
correct endianness. We need to reset the endian during kexec
so do that in the MMU hashtable clear callback.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 1f97e2b..c1f1908 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -442,6 +442,32 @@
}
#endif
+#ifdef __LITTLE_ENDIAN__
+long pseries_big_endian_exceptions(void)
+{
+ long rc;
+
+ while (1) {
+ rc = enable_big_endian_exceptions();
+ if (!H_IS_LONG_BUSY(rc))
+ return rc;
+ mdelay(get_longbusy_msecs(rc));
+ }
+}
+
+static long pseries_little_endian_exceptions(void)
+{
+ long rc;
+
+ while (1) {
+ rc = enable_little_endian_exceptions();
+ if (!H_IS_LONG_BUSY(rc))
+ return rc;
+ mdelay(get_longbusy_msecs(rc));
+ }
+}
+#endif
+
static void __init pSeries_setup_arch(void)
{
panic_timeout = 10;
@@ -698,6 +724,22 @@
/* Now try to figure out if we are running on LPAR */
of_scan_flat_dt(pseries_probe_fw_features, NULL);
+#ifdef __LITTLE_ENDIAN__
+ if (firmware_has_feature(FW_FEATURE_SET_MODE)) {
+ long rc;
+ /*
+ * Tell the hypervisor that we want our exceptions to
+ * be taken in little endian mode. If this fails we don't
+ * want to use BUG() because it will trigger an exception.
+ */
+ rc = pseries_little_endian_exceptions();
+ if (rc) {
+ ppc_md.progress("H_SET_MODE LE exception fail", 0);
+ panic("Could not enable little endian exceptions");
+ }
+ }
+#endif
+
if (firmware_has_feature(FW_FEATURE_LPAR))
hpte_init_lpar();
else