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From:   Suzuki K Poulose <suzuki.poulose@arm.com>
To:     linux-arm-kernel@lists.infradead.org
Cc:     linux-kernel@vger.kernel.org, mathieu.poirier@linaro.org,
        mike.leach@linaro.org, robert.walker@arm.com, mark.rutland@arm.com,
        will.deacon@arm.com, robin.murphy@arm.com, sudeep.holla@arm.com,
        frowand.list@gmail.com, robh@kernel.org, john.horley@arm.com,
        Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: [PATCH v2 09/27] coresight: Add helper for inserting synchronization packets
Date:   Tue,  1 May 2018 10:10:39 +0100
Message-Id: <1525165857-11096-10-git-send-email-suzuki.poulose@arm.com>
In-Reply-To: <1525165857-11096-1-git-send-email-suzuki.poulose@arm.com>
References: <1525165857-11096-1-git-send-email-suzuki.poulose@arm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Right now we open code filling the trace buffer with synchronization
packets when the circular buffer wraps around in different drivers.
Move this to a common place. While at it, clean up the barrier_pkt
array to strip off the trailing '\0'.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 drivers/hwtracing/coresight/coresight-etb10.c   | 12 ++++-------
 drivers/hwtracing/coresight/coresight-priv.h    | 10 ++++++++-
 drivers/hwtracing/coresight/coresight-tmc-etf.c | 27 ++++++++-----------------
 drivers/hwtracing/coresight/coresight-tmc-etr.c | 13 +-----------
 drivers/hwtracing/coresight/coresight.c         |  3 +--
 5 files changed, 23 insertions(+), 42 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
index 580cd38..74232e6 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -202,7 +202,6 @@ static void etb_dump_hw(struct etb_drvdata *drvdata)
 	bool lost = false;
 	int i;
 	u8 *buf_ptr;
-	const u32 *barrier;
 	u32 read_data, depth;
 	u32 read_ptr, write_ptr;
 	u32 frame_off, frame_endoff;
@@ -233,19 +232,16 @@ static void etb_dump_hw(struct etb_drvdata *drvdata)
 
 	depth = drvdata->buffer_depth;
 	buf_ptr = drvdata->buf;
-	barrier = barrier_pkt;
 	for (i = 0; i < depth; i++) {
 		read_data = readl_relaxed(drvdata->base +
 					  ETB_RAM_READ_DATA_REG);
-		if (lost && *barrier) {
-			read_data = *barrier;
-			barrier++;
-		}
-
 		*(u32 *)buf_ptr = read_data;
 		buf_ptr += 4;
 	}
 
+	if (lost)
+		coresight_insert_barrier_packet(drvdata->buf);
+
 	if (frame_off) {
 		buf_ptr -= (frame_endoff * 4);
 		for (i = 0; i < frame_endoff; i++) {
@@ -454,7 +450,7 @@ static void etb_update_buffer(struct coresight_device *csdev,
 		buf_ptr = buf->data_pages[cur] + offset;
 		read_data = readl_relaxed(drvdata->base +
 					  ETB_RAM_READ_DATA_REG);
-		if (lost && *barrier) {
+		if (lost && i < CORESIGHT_BARRIER_PKT_SIZE) {
 			read_data = *barrier;
 			barrier++;
 		}
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index f1d0e21d..2bb0a15 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -64,7 +64,8 @@ static DEVICE_ATTR_RO(name)
 #define coresight_simple_reg64(type, name, lo_off, hi_off)		\
 	__coresight_simple_func(type, NULL, name, lo_off, hi_off)
 
-extern const u32 barrier_pkt[5];
+extern const u32 barrier_pkt[4];
+#define CORESIGHT_BARRIER_PKT_SIZE (sizeof(barrier_pkt))
 
 enum etm_addr_type {
 	ETM_ADDR_TYPE_NONE,
@@ -98,6 +99,13 @@ struct cs_buffers {
 	void			**data_pages;
 };
 
+static inline void coresight_insert_barrier_packet(void *buf)
+{
+	if (buf)
+		memcpy(buf, barrier_pkt, CORESIGHT_BARRIER_PKT_SIZE);
+}
+
+
 static inline void CS_LOCK(void __iomem *addr)
 {
 	do {
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index 2113e93..1dd44fd 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -43,39 +43,28 @@ static void tmc_etb_enable_hw(struct tmc_drvdata *drvdata)
 
 static void tmc_etb_dump_hw(struct tmc_drvdata *drvdata)
 {
-	bool lost = false;
 	char *bufp;
-	const u32 *barrier;
-	u32 read_data, status;
+	u32 read_data, lost;
 	int i;
 
-	/*
-	 * Get a hold of the status register and see if a wrap around
-	 * has occurred.
-	 */
-	status = readl_relaxed(drvdata->base + TMC_STS);
-	if (status & TMC_STS_FULL)
-		lost = true;
-
+	/* Check if the buffer wrapped around. */
+	lost = readl_relaxed(drvdata->base + TMC_STS) & TMC_STS_FULL;
 	bufp = drvdata->buf;
 	drvdata->len = 0;
-	barrier = barrier_pkt;
 	while (1) {
 		for (i = 0; i < drvdata->memwidth; i++) {
 			read_data = readl_relaxed(drvdata->base + TMC_RRD);
 			if (read_data == 0xFFFFFFFF)
-				return;
-
-			if (lost && *barrier) {
-				read_data = *barrier;
-				barrier++;
-			}
-
+				goto done;
 			memcpy(bufp, &read_data, 4);
 			bufp += 4;
 			drvdata->len += 4;
 		}
 	}
+done:
+	if (lost)
+		coresight_insert_barrier_packet(drvdata->buf);
+	return;
 }
 
 static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index fc1ff3f..7af72d7 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -125,9 +125,7 @@ ssize_t tmc_etr_get_sysfs_trace(struct tmc_drvdata *drvdata,
 
 static void tmc_etr_dump_hw(struct tmc_drvdata *drvdata)
 {
-	const u32 *barrier;
 	u32 val;
-	u32 *temp;
 	u64 rwp;
 
 	rwp = tmc_read_rwp(drvdata);
@@ -140,16 +138,7 @@ static void tmc_etr_dump_hw(struct tmc_drvdata *drvdata)
 	if (val & TMC_STS_FULL) {
 		drvdata->buf = drvdata->vaddr + rwp - drvdata->paddr;
 		drvdata->len = drvdata->size;
-
-		barrier = barrier_pkt;
-		temp = (u32 *)drvdata->buf;
-
-		while (*barrier) {
-			*temp = *barrier;
-			temp++;
-			barrier++;
-		}
-
+		coresight_insert_barrier_packet(drvdata->buf);
 	} else {
 		drvdata->buf = drvdata->vaddr;
 		drvdata->len = rwp - drvdata->paddr;
diff --git a/drivers/hwtracing/coresight/coresight.c b/drivers/hwtracing/coresight/coresight.c
index fd0251e..021d8ec 100644
--- a/drivers/hwtracing/coresight/coresight.c
+++ b/drivers/hwtracing/coresight/coresight.c
@@ -58,8 +58,7 @@ static struct list_head *stm_path;
  * beginning of the data collected in a buffer.  That way the decoder knows that
  * it needs to look for another sync sequence.
  */
-const u32 barrier_pkt[5] = {0x7fffffff, 0x7fffffff,
-			    0x7fffffff, 0x7fffffff, 0x0};
+const u32 barrier_pkt[4] = {0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff};
 
 static int coresight_id_match(struct device *dev, void *data)
 {
-- 
2.7.4