powerpc/powernv: opal-kmsg standardise OPAL_BUSY handling

OPAL_CONSOLE_FLUSH is documented as being able to return OPAL_BUSY,
so implement the standard OPAL_BUSY handling for it.

Reviewed-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/platforms/powernv/opal-kmsg.c b/arch/powerpc/platforms/powernv/opal-kmsg.c
index 6f1214d4de926ade09460b989383337a034225d6..f8f41ccce75f1e9db2ece8d2b2a97b0a9afcce27 100644 (file)
--- a/arch/powerpc/platforms/powernv/opal-kmsg.c
+++ b/arch/powerpc/platforms/powernv/opal-kmsg.c
@@ -12,6 +12,7 @@
  */
 
 #include <linux/kmsg_dump.h>
+#include <linux/delay.h>
 
 #include <asm/opal.h>
 #include <asm/opal-api.h>
@@ -26,8 +27,7 @@
 static void force_opal_console_flush(struct kmsg_dumper *dumper,
                                     enum kmsg_dump_reason reason)
 {
-       int i;
-       int64_t ret;
+       s64 rc;
 
        /*
         * Outside of a panic context the pollers will continue to run,
@@ -37,14 +37,22 @@ static void force_opal_console_flush(struct kmsg_dumper *dumper,
                return;
 
        if (opal_check_token(OPAL_CONSOLE_FLUSH)) {
-               ret = opal_console_flush(0);
+               do  {
+                       rc = OPAL_BUSY;
+                       while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
+                               rc = opal_console_flush(0);
+                               if (rc == OPAL_BUSY_EVENT) {
+                                       mdelay(OPAL_BUSY_DELAY_MS);
+                                       opal_poll_events(NULL);
+                               } else if (rc == OPAL_BUSY) {
+                                       mdelay(OPAL_BUSY_DELAY_MS);
+                               }
+                       }
+               } while (rc == OPAL_PARTIAL); /* More to flush */
 
-               if (ret == OPAL_UNSUPPORTED || ret == OPAL_PARAMETER)
-                       return;
-
-               /* Incrementally flush until there's nothing left */
-               while (opal_console_flush(0) != OPAL_SUCCESS);
        } else {
+               int i;
+
                /*
                 * If OPAL_CONSOLE_FLUSH is not implemented in the firmware,
                 * the console can still be flushed by calling the polling