powerpc/rfi-flush: Call setup_rfi_flush() after LPM migration

CVE-2018-3639 (powerpc)

We might have migrated to a machine that uses a different flush type,
or doesn't need flushing at all.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
(cherry picked from 921bc6cf)
[mauricio: backport: pseries.h: update context lines]
Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>

arch/powerpc/platforms/pseries/mobility.c

@@ -314,6 +314,9 @@ void post_mobility_fixup(void)
 		printk(KERN_ERR "Post-mobility device tree update "
 			"failed: %d\n", rc);
 
+	/* Possibly switch to a new RFI flush type */
+	pseries_setup_rfi_flush();
+
 	return;
 }
 

arch/powerpc/platforms/pseries/pseries.h

@@ -81,4 +81,6 @@ extern struct pci_controller_ops pseries_pci_controller_ops;
 
 unsigned long pseries_memory_block_size(void);
 
+void pseries_setup_rfi_flush(void);
+
 #endif /* _PSERIES_PSERIES_H */

arch/powerpc/platforms/pseries/setup.c

@@ -499,7 +499,7 @@ static void __init find_and_init_phbs(void)
 	of_pci_check_probe_only();
 }
 
-static void pseries_setup_rfi_flush(void)
+void pseries_setup_rfi_flush(void)
 {
 	struct h_cpu_char_result result;
 	enum l1d_flush_type types;