linux-kernel - [PATCH 05/10] coresight: etm4x: cleaning up default filter configuration

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Date:	Mon, 18 Jul 2016 13:51:26 -0600
From:	Mathieu Poirier <mathieu.poirier@...aro.org>
To:	linux-arm-kernel@...ts.infradead.org
Cc:	linux-kernel@...r.kernel.org, alexander.shishkin@...ux.intel.com,
	Mathieu Poirier <mathieu.poirier@...aro.org>
Subject: [PATCH 05/10] coresight: etm4x: cleaning up default filter configuration

The default filter configuration was hard to read and included
some redundancy.  This patch attempts to stream line configuration
and improve readability.

No change of functionality is included.

Signed-off-by: Mathieu Poirier <mathieu.poirier@...aro.org>
---
 drivers/hwtracing/coresight/coresight-etm4x.c | 53 ++++++++++++++-------------
 1 file changed, 27 insertions(+), 26 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
index 9978cf7a5600..e348c18086f5 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x.c
@@ -586,39 +586,34 @@ static void etm4_set_default_config(struct etmv4_config *config)
 
 static void etm4_set_default_filter(struct etmv4_config *config)
 {
-	/*
-	 * TRCVICTLR::SSSTATUS == 1, the start-stop logic is
-	 * in the started state
-	 */
-	config->vinst_ctrl |= BIT(9);
+	u64 start, stop, access_type = 0;
 
 	/*
 	 * Configure address range comparator '0' to encompass all
 	 * possible addresses.
 	 */
+	start = 0x0;
+	stop = ~0x0;
 
-	/* First half of default address comparator: start at address 0 */
-	config->addr_val[ETM_DEFAULT_ADDR_COMP] = 0x0;
-	/* trace instruction addresses */
-	config->addr_acc[ETM_DEFAULT_ADDR_COMP] &= ~(BIT(0) | BIT(1));
-	/* EXLEVEL_NS, bits[12:15], only trace application and kernel space */
-	config->addr_acc[ETM_DEFAULT_ADDR_COMP] |= ETM_EXLEVEL_NS_HYP;
-	/* EXLEVEL_S, bits[11:8], don't trace anything in secure state */
-	config->addr_acc[ETM_DEFAULT_ADDR_COMP] |= (ETM_EXLEVEL_S_APP |
-						    ETM_EXLEVEL_S_OS |
-						    ETM_EXLEVEL_S_HYP);
-	config->addr_type[ETM_DEFAULT_ADDR_COMP] = ETM_ADDR_TYPE_RANGE;
+	/* EXLEVEL_NS, bits[12:15], always stay away from hypervisor mode. */
+	access_type = ETM_EXLEVEL_NS_HYP;
 
 	/*
-	 * Second half of default address comparator: go all
-	 * the way to the top.
-	*/
-	config->addr_val[ETM_DEFAULT_ADDR_COMP + 1] = ~0x0;
-	/* trace instruction addresses */
-	config->addr_acc[ETM_DEFAULT_ADDR_COMP + 1] &= ~(BIT(0) | BIT(1));
-	/* Address comparator type must be equal for both halves */
-	config->addr_acc[ETM_DEFAULT_ADDR_COMP + 1] =
-					config->addr_acc[ETM_DEFAULT_ADDR_COMP];
+	 * EXLEVEL_S, bits[11:8], don't trace anything happening
+	 * in secure state.
+	 */
+	access_type |= (ETM_EXLEVEL_S_APP	|
+			ETM_EXLEVEL_S_OS	|
+			ETM_EXLEVEL_S_HYP);
+
+	/* First half of default address comparator */
+	config->addr_val[ETM_DEFAULT_ADDR_COMP] = start;
+	config->addr_acc[ETM_DEFAULT_ADDR_COMP] = access_type;
+	config->addr_type[ETM_DEFAULT_ADDR_COMP] = ETM_ADDR_TYPE_RANGE;
+
+	/* Second half of default address comparator */
+	config->addr_val[ETM_DEFAULT_ADDR_COMP + 1] = stop;
+	config->addr_acc[ETM_DEFAULT_ADDR_COMP + 1] = access_type;
 	config->addr_type[ETM_DEFAULT_ADDR_COMP + 1] = ETM_ADDR_TYPE_RANGE;
 
 	/*
@@ -627,7 +622,13 @@ static void etm4_set_default_filter(struct etmv4_config *config)
 	 */
 	config->viiectlr = BIT(0);
 
-	/* no start-stop filtering for ViewInst */
+	/*
+	 * TRCVICTLR::SSSTATUS == 1, the start-stop logic is
+	 * in the started state
+	 */
+	config->vinst_ctrl |= BIT(9);
+
+	/* No start-stop filtering for ViewInst */
 	config->vissctlr = 0x0;
 }
 
-- 
2.7.4