[S390] add hook to reenable mss after hibernation

Reenable multiple subchannel sets after hibernation,
prior to the device callbacks.

Cc: <stable@kernel.org>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 8 insertions, 0 deletions

diff --git a/arch/s390/kernel/swsusp_asm64.S b/arch/s390/kernel/swsusp_asm64.S
index b354427e03b7..c56d3f56d020 100644
--- a/arch/s390/kernel/swsusp_asm64.S
+++ b/arch/s390/kernel/swsusp_asm64.S
@@ -256,6 +256,9 @@ restore_registers:
         lghi    %r2,0
         brasl   %r14,arch_set_page_states
 
+        /* Reinitialize the channel subsystem */
+        brasl   %r14,channel_subsystem_reinit
+
         /* Return 0 */
         lmg     %r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15)
         lghi    %r2,0
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 19635d47dede..511649115bd7 100644
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -1043,6 +1043,11 @@ static int __init channel_subsystem_init_sync(void)
 }
 subsys_initcall_sync(channel_subsystem_init_sync);
 
+void channel_subsystem_reinit(void)
+{
+        chsc_enable_facility(CHSC_SDA_OC_MSS);
+}
+
 #ifdef CONFIG_PROC_FS
 static ssize_t cio_settle_write(struct file *file, const char __user *buf,
                                 size_t count, loff_t *ppos)