s390/ap: Extend struct ap_queue_status with some convenience fields

Sometimes there is a different view of the AP status word
needed. So here is slight rework of the struct ap_queue_status
to open up the possibility to have different ways of accessing
the AP status bits and fields.

The new struct ap_queue_status

struct ap_queue_status {
	union {
		unsigned int value			: 32;
		struct {
			unsigned int status_bits	: 8;
			unsigned int rc			: 8;
			unsigned int			: 16;
		};
		struct {
			unsigned int queue_empty	: 1;
			unsigned int replies_waiting	: 1;
			unsigned int queue_full		: 1;
			unsigned int			: 3;
			unsigned int async		: 1;
			unsigned int irq_enabled	: 1;
			unsigned int response_code	: 8;
			unsigned int			: 16;
		};
	};
};

comprises the old struct ap_queue_status but extends it
to have this also accessible as an unsigned int required
for example for a simple print or trace of the whole value.

Note that this rework is fully backward compatible to the
existing code exploiting the struct ap_queue_status.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Anthony Krowiak <akrowiak@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

1 files changed, 22 insertions, 8 deletions

diff --git a/arch/s390/include/asm/ap.h b/arch/s390/include/asm/ap.h
index 56817990c73d..b24459f692fa 100644
--- a/arch/s390/include/asm/ap.h
+++ b/arch/s390/include/asm/ap.h
@@ -38,16 +38,30 @@ typedef unsigned int ap_qid_t;
  * The ap queue status word is returned by all three AP functions
  * (PQAP, NQAP and DQAP).  There's a set of flags in the first
  * byte, followed by a 1 byte response code.
+ *
+ * For convenience the 'value' field is a 32 bit access of the
+ * whole status and the 'status_bits' and 'rc' fields comprise
+ * the leftmost 8 status bits and the response_code.
  */
 struct ap_queue_status {
-	unsigned int queue_empty	: 1;
-	unsigned int replies_waiting	: 1;
-	unsigned int queue_full		: 1;
-	unsigned int			: 3;
-	unsigned int async		: 1;
-	unsigned int irq_enabled	: 1;
-	unsigned int response_code	: 8;
-	unsigned int			: 16;
+	union {
+		unsigned int value			: 32;
+		struct {
+			unsigned int status_bits	: 8;
+			unsigned int rc			: 8;
+			unsigned int			: 16;
+		};
+		struct {
+			unsigned int queue_empty	: 1;
+			unsigned int replies_waiting	: 1;
+			unsigned int queue_full		: 1;
+			unsigned int			: 3;
+			unsigned int async		: 1;
+			unsigned int irq_enabled	: 1;
+			unsigned int response_code	: 8;
+			unsigned int			: 16;
+		};
+	};
 };
 
 /*