4 files changed, 23 insertions, 2 deletions

diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h
index 9a87b4401a41..40157e2ca691 100644
--- a/arch/powerpc/include/asm/opal.h
+++ b/arch/powerpc/include/asm/opal.h
@@ -156,6 +156,7 @@ extern int opal_enter_rtas(struct rtas_args *args,
 #define OPAL_FLASH_UPDATE                       78
 #define OPAL_GET_MSG                            85
 #define OPAL_CHECK_ASYNC_COMPLETION             86
+#define OPAL_SYNC_HOST_REBOOT                   87
 
 #ifndef __ASSEMBLY__
 
@@ -828,6 +829,7 @@ int64_t opal_update_flash(uint64_t blk_list);
 
 int64_t opal_get_msg(uint64_t buffer, size_t size);
 int64_t opal_check_completion(uint64_t buffer, size_t size, uint64_t token);
+int64_t opal_sync_host_reboot(void);
 
 /* Internal functions */
 extern int early_init_dt_scan_opal(unsigned long node, const char *uname, int depth, void *data);
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
index 719aa5c325c6..3e8829c40fbb 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -128,3 +128,4 @@ OPAL_CALL(opal_manage_flash,			OPAL_FLASH_MANAGE);
 OPAL_CALL(opal_update_flash,                    OPAL_FLASH_UPDATE);
 OPAL_CALL(opal_get_msg,                         OPAL_GET_MSG);
 OPAL_CALL(opal_check_completion,                OPAL_CHECK_ASYNC_COMPLETION);
+OPAL_CALL(opal_sync_host_reboot,                OPAL_SYNC_HOST_REBOOT);
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 7a184a0ff183..65499adaecff 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -20,6 +20,7 @@
 #include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/kobject.h>
+#include <linux/delay.h>
 #include <asm/opal.h>
 #include <asm/firmware.h>
 #include <asm/mce.h>
@@ -482,10 +483,25 @@ subsys_initcall(opal_init);
 void opal_shutdown(void)
 {
         unsigned int i;
+        long rc = OPAL_BUSY;
 
+        /* First free interrupts, which will also mask them */
         for (i = 0; i < opal_irq_count; i++) {
                 if (opal_irqs[i])
                         free_irq(opal_irqs[i], NULL);
                 opal_irqs[i] = 0;
         }
+
+        /*
+         * Then sync with OPAL which ensure anything that can
+         * potentially write to our memory has completed such
+         * as an ongoing dump retrieval
+         */
+        while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
+                rc = opal_sync_host_reboot();
+                if (rc == OPAL_BUSY)
+                        opal_poll_events(NULL);
+                else
+                        mdelay(10);
+        }
 }
diff --git a/arch/powerpc/platforms/powernv/setup.c b/arch/powerpc/platforms/powernv/setup.c
index 19884b2a51b4..a932feb2901c 100644
--- a/arch/powerpc/platforms/powernv/setup.c
+++ b/arch/powerpc/platforms/powernv/setup.c
@@ -145,8 +145,10 @@ static void pnv_shutdown(void)
         /* Let the PCI code clear up IODA tables */
         pnv_pci_shutdown();
 
-        /* And unregister all OPAL interrupts so they don't fire
-         * up while we kexec
+        /*
+         * Stop OPAL activity: Unregister all OPAL interrupts so they
+         * don't fire up while we kexec and make sure all potentially
+         * DMA'ing ops are complete (such as dump retrieval).
          */
         opal_shutdown();
 }