[PATCH 2/6] x86/platform/uv/BAU: Add status_mmr_loc to locate message status bits

[Andrew Banman]

The location of the ERROR and BUSY status bits depends on the descriptor
index, i.e. the CPU, of the message. We determine this location ahead of
the wait_completion loop to avoid repeating the calculation.

Split out the status location calculation into a new routine,
status_mmr_loc, to be used within each uv*_wait_completion routine.

Signed-off-by: Andrew Banman <abanman@xxxxxxx>
Acked-by: Mike Travis <mike.travis@xxxxxxx>
---
 arch/x86/platform/uv/tlb_uv.c | 41 +++++++++++++++++++++++++----------------
 1 file changed, 25 insertions(+), 16 deletions(-)

Index: community/arch/x86/platform/uv/tlb_uv.c
===================================================================
--- community.orig/arch/x86/platform/uv/tlb_uv.c
+++ community/arch/x86/platform/uv/tlb_uv.c
@@ -533,6 +533,22 @@ static inline void end_uvhub_quiesce(str
 	atom_asr(-1, (struct atomic_short *)&hmaster->uvhub_quiesce);
 }
 
+/*
+ * The ERROR and BUSY status registers are located pairwise over the STATUS_0
+ * and STATUS_1 mmrs; each an array[32] of 2 bits. Given CPU desc, determine
+ * the correct mmr and index for the message status.
+ */
+void status_mmr_loc(unsigned long *mmr, int *index, int desc)
+{
+	if (desc < UV_CPUS_PER_AS) {
+		*mmr = UVH_LB_BAU_SB_ACTIVATION_STATUS_0;
+		*index = desc * UV_ACT_STATUS_SIZE;
+	} else {
+		*mmr = UVH_LB_BAU_SB_ACTIVATION_STATUS_1;
+		*index = (desc - UV_CPUS_PER_AS) * UV_ACT_STATUS_SIZE;
+	}
+}
+
 static unsigned long uv1_read_status(unsigned long mmr_offset, int right_shift)
 {
 	unsigned long descriptor_status;
@@ -548,13 +564,16 @@ static unsigned long uv1_read_status(uns
  * return COMPLETE, RETRY(PLUGGED or TIMEOUT) or GIVEUP
  */
 static int uv1_wait_completion(struct bau_desc *bau_desc,
-				unsigned long mmr_offset, int right_shift,
 				struct bau_control *bcp, long try)
 {
 	unsigned long descriptor_status;
+	unsigned long mmr_offset;
+	int right_shift;
+	int desc = bcp->uvhub_cpu;
 	cycles_t ttm;
 	struct ptc_stats *stat = bcp->statp;
 
+	status_mmr_loc(&mmr_offset, &right_shift, desc);
 	descriptor_status = uv1_read_status(mmr_offset, right_shift);
 	/* spin on the status MMR, waiting for it to go idle */
 	while ((descriptor_status != DS_IDLE)) {
@@ -640,15 +659,17 @@ int handle_uv2_busy(struct bau_control *
 }
 
 static int uv2_3_wait_completion(struct bau_desc *bau_desc,
-				unsigned long mmr_offset, int right_shift,
 				struct bau_control *bcp, long try)
 {
 	unsigned long descriptor_stat;
+	unsigned long mmr_offset;
 	cycles_t ttm;
 	int desc = bcp->uvhub_cpu;
+	int right_shift;
 	long busy_reps = 0;
 	struct ptc_stats *stat = bcp->statp;
 
+	status_mmr_loc(&mmr_offset, &right_shift, desc);
 	descriptor_stat = uv2_3_read_status(mmr_offset, right_shift, desc);
 
 	/* spin on the status MMR, waiting for it to go idle */
@@ -712,22 +733,10 @@ static int uv2_3_wait_completion(struct
  */
 static int wait_completion(struct bau_desc *bau_desc, struct bau_control *bcp, long try)
 {
-	int right_shift;
-	unsigned long mmr_offset;
-	int desc = bcp->uvhub_cpu;
-
-	if (desc < UV_CPUS_PER_AS) {
-		mmr_offset = UVH_LB_BAU_SB_ACTIVATION_STATUS_0;
-		right_shift = desc * UV_ACT_STATUS_SIZE;
-	} else {
-		mmr_offset = UVH_LB_BAU_SB_ACTIVATION_STATUS_1;
-		right_shift = ((desc - UV_CPUS_PER_AS) * UV_ACT_STATUS_SIZE);
-	}
-
 	if (bcp->uvhub_version == 1)
-		return uv1_wait_completion(bau_desc, mmr_offset, right_shift, bcp, try);
+		return uv1_wait_completion(bau_desc, bcp, try);
 	else
-		return uv2_3_wait_completion(bau_desc, mmr_offset, right_shift, bcp, try);
+		return uv2_3_wait_completion(bau_desc, bcp, try);
 }
 
 /*