pseries: Add H_SET_MODE to change exception endianness

[linux-drm-fsl-dcu.git] / arch / powerpc / platforms / pseries / setup.c

diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 1f97e2b87a62b85d30bf848a8dbab31938304f21..c1f1908587011d6d131dd56bdf2e1cb283c41128 100644 (file)
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -442,6 +442,32 @@ static void pSeries_machine_kexec(struct kimage *image)
 }
 #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 @@ static int __init pSeries_probe(void)
        /* 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