linux-kernel - [PATCH 2/6] x86/platform/uv/BAU: Add status_mmr

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Date:   Tue, 14 Feb 2017 19:58:47 -0600
From:   Andrew Banman <abanman@....com>
To:     mingo@...hat.com
Cc:     akpm@...ux-foundation.org, tglx@...utronix.de, hpa@...or.com,
        mike.travis@....com, rja@....com, sivanich@....com, x86@...nel.org,
        linux-kernel@...r.kernel.org, abanman@....com
Subject: [PATCH 2/6] x86/platform/uv/BAU: Add status_mmr_loc to locate message status bits

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@....com>
Acked-by: Mike Travis <mike.travis@....com>
---
 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);
 }
 
 /*