From 8a519235c3c37663e54e37a89d05a86c0a2c90c8 Mon Sep 17 00:00:00 2001
From: James Clark <james.clark@arm.com>
Date: Thu, 23 Nov 2023 12:04:56 +0000
Subject: coresight: Fix uninitialized struct warnings

These warnings would be hit with the following W=1 build change so
initialize all structs properly.

Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20231123120459.287578-2-james.clark@arm.com
---
 drivers/hwtracing/coresight/coresight-cti-core.c   | 2 +-
 drivers/hwtracing/coresight/coresight-etb10.c      | 2 +-
 drivers/hwtracing/coresight/coresight-etm3x-core.c | 2 +-
 drivers/hwtracing/coresight/coresight-etm4x-core.c | 2 +-
 drivers/hwtracing/coresight/coresight-funnel.c     | 4 ++--
 drivers/hwtracing/coresight/coresight-replicator.c | 2 +-
 drivers/hwtracing/coresight/coresight-stm.c        | 2 +-
 drivers/hwtracing/coresight/coresight-tmc-core.c   | 2 +-
 drivers/hwtracing/coresight/coresight-tpda.c       | 2 +-
 drivers/hwtracing/coresight/coresight-tpdm.c       | 2 +-
 drivers/hwtracing/coresight/coresight-tpiu.c       | 2 +-
 drivers/hwtracing/coresight/ultrasoc-smb.c         | 2 +-
 12 files changed, 13 insertions(+), 13 deletions(-)

(limited to 'drivers/hwtracing')

diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c
index 3999d0a2cb60..e805617020d0 100644
--- a/drivers/hwtracing/coresight/coresight-cti-core.c
+++ b/drivers/hwtracing/coresight/coresight-cti-core.c
@@ -974,7 +974,7 @@ static const struct amba_id cti_ids[] = {
 	CS_AMBA_ID(0x000bb9aa), /* CTI - C-A73 */
 	CS_AMBA_UCI_ID(0x000bb9da, uci_id_cti), /* CTI - C-A35 */
 	CS_AMBA_UCI_ID(0x000bb9ed, uci_id_cti), /* Coresight CTI (SoC 600) */
-	{ 0, 0},
+	{ 0, 0, NULL },
 };
 
 MODULE_DEVICE_TABLE(amba, cti_ids);
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
index fa80039e0821..05e21cffd33b 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -837,7 +837,7 @@ static const struct amba_id etb_ids[] = {
 		.id	= 0x000bb907,
 		.mask	= 0x000fffff,
 	},
-	{ 0, 0},
+	{ 0, 0, NULL },
 };
 
 MODULE_DEVICE_TABLE(amba, etb_ids);
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
index 116a91d90ac2..8da1622e0837 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
@@ -1003,7 +1003,7 @@ static const struct amba_id etm_ids[] = {
 	CS_AMBA_ID_DATA(0x000bb95f, "PTM 1.1"),
 	/* PTM 1.1 Qualcomm */
 	CS_AMBA_ID_DATA(0x000b006f, "PTM 1.1"),
-	{ 0, 0},
+	{ 0, 0, NULL},
 };
 
 MODULE_DEVICE_TABLE(amba, etm_ids);
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index ce1995a2827f..c5ea808ea662 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -2390,7 +2390,7 @@ static const struct of_device_id etm4_sysreg_match[] = {
 
 #ifdef CONFIG_ACPI
 static const struct acpi_device_id etm4x_acpi_ids[] = {
-	{"ARMHC500", 0}, /* ARM CoreSight ETM4x */
+	{"ARMHC500", 0, 0, 0}, /* ARM CoreSight ETM4x */
 	{}
 };
 MODULE_DEVICE_TABLE(acpi, etm4x_acpi_ids);
diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
index a5b1fc787766..ef1a0abfee4e 100644
--- a/drivers/hwtracing/coresight/coresight-funnel.c
+++ b/drivers/hwtracing/coresight/coresight-funnel.c
@@ -350,7 +350,7 @@ MODULE_DEVICE_TABLE(of, static_funnel_match);
 
 #ifdef CONFIG_ACPI
 static const struct acpi_device_id static_funnel_ids[] = {
-	{"ARMHC9FE", 0},
+	{"ARMHC9FE", 0, 0, 0},
 	{},
 };
 
@@ -391,7 +391,7 @@ static const struct amba_id dynamic_funnel_ids[] = {
 		.id     = 0x000bb9eb,
 		.mask   = 0x000fffff,
 	},
-	{ 0, 0},
+	{ 0, 0, NULL },
 };
 
 MODULE_DEVICE_TABLE(amba, dynamic_funnel_ids);
diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c
index 91d93060dda5..73452d9dc13b 100644
--- a/drivers/hwtracing/coresight/coresight-replicator.c
+++ b/drivers/hwtracing/coresight/coresight-replicator.c
@@ -363,7 +363,7 @@ MODULE_DEVICE_TABLE(of, static_replicator_match);
 
 #ifdef CONFIG_ACPI
 static const struct acpi_device_id static_replicator_acpi_ids[] = {
-	{"ARMHC985", 0}, /* ARM CoreSight Static Replicator */
+	{"ARMHC985", 0, 0, 0}, /* ARM CoreSight Static Replicator */
 	{}
 };
 
diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
index a1c27c901ad1..891ee64efed8 100644
--- a/drivers/hwtracing/coresight/coresight-stm.c
+++ b/drivers/hwtracing/coresight/coresight-stm.c
@@ -950,7 +950,7 @@ static const struct dev_pm_ops stm_dev_pm_ops = {
 static const struct amba_id stm_ids[] = {
 	CS_AMBA_ID_DATA(0x000bb962, "STM32"),
 	CS_AMBA_ID_DATA(0x000bb963, "STM500"),
-	{ 0, 0},
+	{ 0, 0, NULL },
 };
 
 MODULE_DEVICE_TABLE(amba, stm_ids);
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
index 7ec5365e2b64..39bae35d4ffd 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-core.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
@@ -594,7 +594,7 @@ static const struct amba_id tmc_ids[] = {
 	CS_AMBA_ID(0x000bb9e9),
 	/* Coresight SoC 600 TMC-ETF */
 	CS_AMBA_ID(0x000bb9ea),
-	{ 0, 0},
+	{ 0, 0, NULL },
 };
 
 MODULE_DEVICE_TABLE(amba, tmc_ids);
diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c
index 5f82737c37bb..4ac954f4bc13 100644
--- a/drivers/hwtracing/coresight/coresight-tpda.c
+++ b/drivers/hwtracing/coresight/coresight-tpda.c
@@ -300,7 +300,7 @@ static struct amba_id tpda_ids[] = {
 		.id     = 0x000f0f00,
 		.mask   = 0x000fff00,
 	},
-	{ 0, 0},
+	{ 0, 0, NULL },
 };
 
 static struct amba_driver tpda_driver = {
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index 97654aa4b772..bd13a548375c 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -933,7 +933,7 @@ static struct amba_id tpdm_ids[] = {
 		.id = 0x000f0e00,
 		.mask = 0x000fff00,
 	},
-	{ 0, 0},
+	{ 0, 0, NULL },
 };
 
 static struct amba_driver tpdm_driver = {
diff --git a/drivers/hwtracing/coresight/coresight-tpiu.c b/drivers/hwtracing/coresight/coresight-tpiu.c
index 59eac93fd6bb..7e69048ac944 100644
--- a/drivers/hwtracing/coresight/coresight-tpiu.c
+++ b/drivers/hwtracing/coresight/coresight-tpiu.c
@@ -218,7 +218,7 @@ static const struct amba_id tpiu_ids[] = {
 		.id	= 0x000bb9e7,
 		.mask	= 0x000fffff,
 	},
-	{ 0, 0},
+	{ 0, 0, NULL },
 };
 
 MODULE_DEVICE_TABLE(amba, tpiu_ids);
diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c
index 10e886455b8b..f0b6806202d1 100644
--- a/drivers/hwtracing/coresight/ultrasoc-smb.c
+++ b/drivers/hwtracing/coresight/ultrasoc-smb.c
@@ -586,7 +586,7 @@ static void smb_remove(struct platform_device *pdev)
 
 #ifdef CONFIG_ACPI
 static const struct acpi_device_id ultrasoc_smb_acpi_match[] = {
-	{"HISI03A1", 0},
+	{"HISI03A1", 0, 0, 0},
 	{}
 };
 MODULE_DEVICE_TABLE(acpi, ultrasoc_smb_acpi_match);
-- 
cgit v1.2.3


From 54daf07e63321d98473777527ce4853fa8eac33d Mon Sep 17 00:00:00 2001
From: James Clark <james.clark@arm.com>
Date: Thu, 23 Nov 2023 12:04:57 +0000
Subject: coresight: etm3x: Fix build warning

The missing * in the comment block causes the following warning, so fix
it:

  hwtracing/coresight/coresight-etm3x-core.c:118: warning: bad line:

Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20231123120459.287578-3-james.clark@arm.com
---
 drivers/hwtracing/coresight/coresight-etm3x-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'drivers/hwtracing')

diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
index 8da1622e0837..74ae26911b8a 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
@@ -115,7 +115,7 @@ static void etm_clr_pwrup(struct etm_drvdata *drvdata)
  *
  * Basically the same as @coresight_timeout except for the register access
  * method where we have to account for CP14 configurations.
-
+ *
  * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if
  * TIMEOUT_US has elapsed, which ever happens first.
  */
-- 
cgit v1.2.3


From a7195f3f93836f518e07da11d0b068e71149d17e Mon Sep 17 00:00:00 2001
From: James Clark <james.clark@arm.com>
Date: Thu, 23 Nov 2023 12:04:58 +0000
Subject: coresight: Fix undeclared variable warnings from sparse checker

Including the header with the declarations fixes the following warning
with a C=1 build:

  coresight-cfg-afdo.c:102:27: warning: symbol 'strobe_etm4x' was not declared. Should it be static?
  coresight-cfg-afdo.c:141:26: warning: symbol 'afdo_etm4x' was not declared. Should it be static?

Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20231123120459.287578-4-james.clark@arm.com
---
 drivers/hwtracing/coresight/coresight-cfg-afdo.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'drivers/hwtracing')

diff --git a/drivers/hwtracing/coresight/coresight-cfg-afdo.c b/drivers/hwtracing/coresight/coresight-cfg-afdo.c
index 84b31184252b..e794f2e145fa 100644
--- a/drivers/hwtracing/coresight/coresight-cfg-afdo.c
+++ b/drivers/hwtracing/coresight/coresight-cfg-afdo.c
@@ -9,6 +9,7 @@
 /* ETMv4 includes and features */
 #if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM4X)
 #include "coresight-etm4x-cfg.h"
+#include "coresight-cfg-preload.h"
 
 /* preload configurations and features */
 
-- 
cgit v1.2.3


From d999c7dd52790e294d78d06e6535e318275c1ea5 Mon Sep 17 00:00:00 2001
From: James Clark <james.clark@arm.com>
Date: Thu, 23 Nov 2023 12:04:59 +0000
Subject: coresight: Make current W=1 warnings default

Similarly to drivers/gpu/drm/amd/amdgpu/Makefile and
fs/btrfs/Makefile, copy the current set of W=1 warnings from
Makefile.extrawarn to the coresight makefile to make them default.
Unfortunately there is no easy way to do this without copying.

In addition to the default set of warnings, add -Wno-sign-compare to
disable that warning. That's because Makefile.extrawarn does some extra
steps to disable some -Wextra warnings unless W=2 or W=3 are used.
That's the only one that's needed for Coresight, so disable it.

Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20231123120459.287578-5-james.clark@arm.com
---
 drivers/hwtracing/coresight/Makefile | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

(limited to 'drivers/hwtracing')

diff --git a/drivers/hwtracing/coresight/Makefile b/drivers/hwtracing/coresight/Makefile
index 995d3b2c76df..4ba478211b31 100644
--- a/drivers/hwtracing/coresight/Makefile
+++ b/drivers/hwtracing/coresight/Makefile
@@ -2,6 +2,26 @@
 #
 # Makefile for CoreSight drivers.
 #
+
+# Current W=1 warnings
+subdir-ccflags-y += -Wextra -Wunused -Wno-unused-parameter
+subdir-ccflags-y += -Wmissing-declarations
+subdir-ccflags-y += -Wmissing-format-attribute
+subdir-ccflags-y += -Wmissing-prototypes
+subdir-ccflags-y += -Wold-style-definition
+subdir-ccflags-y += -Wmissing-include-dirs
+subdir-ccflags-y += -Wno-sign-compare
+condflags := \
+	$(call cc-option, -Wrestrict)				\
+	$(call cc-option, -Wunused-but-set-variable)		\
+	$(call cc-option, -Wunused-const-variable)		\
+	$(call cc-option, -Wpacked-not-aligned)			\
+	$(call cc-option, -Wformat-overflow)			\
+	$(call cc-option, -Wformat-truncation)			\
+	$(call cc-option, -Wstringop-overflow)			\
+	$(call cc-option, -Wstringop-truncation)
+subdir-ccflags-y += $(condflags)
+
 obj-$(CONFIG_CORESIGHT) += coresight.o
 coresight-y := coresight-core.o  coresight-etm-perf.o coresight-platform.o \
 		coresight-sysfs.o coresight-syscfg.o coresight-config.o \
-- 
cgit v1.2.3


From dd95255d44c05c9977f962bf0f2afe5e11f8ab3e Mon Sep 17 00:00:00 2001
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Fri, 5 Jan 2024 13:33:32 +0100
Subject: coresight: make coresight_bustype const

Now that the driver core can properly handle constant struct bus_type,
move the coresight_bustype variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: James Clark <james.clark@arm.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/2024010531-tinfoil-avert-4a57@gregkh
---
 drivers/hwtracing/coresight/coresight-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'drivers/hwtracing')

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index d7f0e231feb9..5dde597403b3 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -1799,7 +1799,7 @@ done:
 }
 EXPORT_SYMBOL_GPL(coresight_alloc_device_name);
 
-struct bus_type coresight_bustype = {
+const struct bus_type coresight_bustype = {
 	.name	= "coresight",
 };
 
-- 
cgit v1.2.3


From f68bbe4dcfa303164922bc331d2e8d38ed2d4f23 Mon Sep 17 00:00:00 2001
From: James Clark <james.clark@arm.com>
Date: Mon, 29 Jan 2024 15:40:32 +0000
Subject: coresight: Fix issue where a source device's helpers aren't disabled

The linked commit reverts the change that accidentally used some sysfs
enable/disable functions from Perf which broke the refcounting, but it
also removes the fact that the sysfs disable function disabled the
helpers.

Add a new wrapper function that does both which is used by both Perf and
sysfs, and label the sysfs disable function appropriately. The naming of
all of the functions will be tidied up later to avoid this happening
again.

Fixes: 287e82cf69aa ("coresight: Fix crash when Perf and sysfs modes are used concurrently")
Signed-off-by: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20240129154050.569566-2-james.clark@arm.com
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 drivers/hwtracing/coresight/coresight-core.c     | 30 ++++++++++++++++++------
 drivers/hwtracing/coresight/coresight-etm-perf.c |  2 +-
 drivers/hwtracing/coresight/coresight-priv.h     |  2 +-
 3 files changed, 25 insertions(+), 9 deletions(-)

(limited to 'drivers/hwtracing')

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 5dde597403b3..1dd3cd46fda4 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -441,8 +441,26 @@ static void coresight_disable_helpers(struct coresight_device *csdev)
 	}
 }
 
+/*
+ * Helper function to call source_ops(csdev)->disable and also disable the
+ * helpers.
+ *
+ * There is an imbalance between coresight_enable_path() and
+ * coresight_disable_path(). Enabling also enables the source's helpers as part
+ * of the path, but disabling always skips the first item in the path (which is
+ * the source), so sources and their helpers don't get disabled as part of that
+ * function and we need the extra step here.
+ */
+void coresight_disable_source(struct coresight_device *csdev, void *data)
+{
+	if (source_ops(csdev)->disable)
+		source_ops(csdev)->disable(csdev, data);
+	coresight_disable_helpers(csdev);
+}
+EXPORT_SYMBOL_GPL(coresight_disable_source);
+
 /**
- *  coresight_disable_source - Drop the reference count by 1 and disable
+ *  coresight_disable_source_sysfs - Drop the reference count by 1 and disable
  *  the device if there are no users left.
  *
  *  @csdev: The coresight device to disable
@@ -451,17 +469,15 @@ static void coresight_disable_helpers(struct coresight_device *csdev)
  *
  *  Returns true if the device has been disabled.
  */
-bool coresight_disable_source(struct coresight_device *csdev, void *data)
+static bool coresight_disable_source_sysfs(struct coresight_device *csdev,
+					   void *data)
 {
 	if (atomic_dec_return(&csdev->refcnt) == 0) {
-		if (source_ops(csdev)->disable)
-			source_ops(csdev)->disable(csdev, data);
-		coresight_disable_helpers(csdev);
+		coresight_disable_source(csdev, data);
 		csdev->enable = false;
 	}
 	return !csdev->enable;
 }
-EXPORT_SYMBOL_GPL(coresight_disable_source);
 
 /*
  * coresight_disable_path_from : Disable components in the given path beyond
@@ -1204,7 +1220,7 @@ void coresight_disable(struct coresight_device *csdev)
 	if (ret)
 		goto out;
 
-	if (!csdev->enable || !coresight_disable_source(csdev, NULL))
+	if (!csdev->enable || !coresight_disable_source_sysfs(csdev, NULL))
 		goto out;
 
 	switch (csdev->subtype.source_subtype) {
diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c
index a52cfcce25d6..c0c60e6a1703 100644
--- a/drivers/hwtracing/coresight/coresight-etm-perf.c
+++ b/drivers/hwtracing/coresight/coresight-etm-perf.c
@@ -589,7 +589,7 @@ static void etm_event_stop(struct perf_event *event, int mode)
 		return;
 
 	/* stop tracer */
-	source_ops(csdev)->disable(csdev, event);
+	coresight_disable_source(csdev, event);
 
 	/* tell the core */
 	event->hw.state = PERF_HES_STOPPED;
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index 767076e07970..30c051055e54 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -233,6 +233,6 @@ void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev);
 struct coresight_device *coresight_get_percpu_sink(int cpu);
 int coresight_enable_source(struct coresight_device *csdev, enum cs_mode mode,
 			    void *data);
-bool coresight_disable_source(struct coresight_device *csdev, void *data);
+void coresight_disable_source(struct coresight_device *csdev, void *data);
 
 #endif
-- 
cgit v1.2.3


From a0fef3f05cf36338d471e8f35a9ced88a054d583 Mon Sep 17 00:00:00 2001
From: James Clark <james.clark@arm.com>
Date: Mon, 29 Jan 2024 15:40:33 +0000
Subject: coresight: Make language around "activated" sinks consistent

Activated has the specific meaning of a sink that's selected for use by
the user via sysfs. But comments in some code that's shared by Perf use
the same word, so in those cases change them to just say "selected"
instead. With selected implying either via Perf or "activated" via
sysfs.

coresight_get_enabled_sink() doesn't actually get an enabled sink, it
only gets an activated one, so change that too.

And change the activated variable name to include "sysfs" so it can't
be confused as a general status.

Signed-off-by: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20240129154050.569566-3-james.clark@arm.com
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 drivers/hwtracing/coresight/coresight-core.c | 51 +++++++++++-----------------
 drivers/hwtracing/coresight/coresight-priv.h |  2 --
 2 files changed, 19 insertions(+), 34 deletions(-)

(limited to 'drivers/hwtracing')

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 1dd3cd46fda4..37e59052e877 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -500,7 +500,7 @@ static void coresight_disable_path_from(struct list_head *path,
 		/*
 		 * ETF devices are tricky... They can be a link or a sink,
 		 * depending on how they are configured.  If an ETF has been
-		 * "activated" it will be configured as a sink, otherwise
+		 * selected as a sink it will be configured as a sink, otherwise
 		 * go ahead with the link configuration.
 		 */
 		if (type == CORESIGHT_DEV_TYPE_LINKSINK)
@@ -578,7 +578,7 @@ int coresight_enable_path(struct list_head *path, enum cs_mode mode,
 		/*
 		 * ETF devices are tricky... They can be a link or a sink,
 		 * depending on how they are configured.  If an ETF has been
-		 * "activated" it will be configured as a sink, otherwise
+		 * selected as a sink it will be configured as a sink, otherwise
 		 * go ahead with the link configuration.
 		 */
 		if (type == CORESIGHT_DEV_TYPE_LINKSINK)
@@ -635,15 +635,21 @@ struct coresight_device *coresight_get_sink(struct list_head *path)
 	return csdev;
 }
 
+/**
+ * coresight_find_activated_sysfs_sink - returns the first sink activated via
+ * sysfs using connection based search starting from the source reference.
+ *
+ * @csdev: Coresight source device reference
+ */
 static struct coresight_device *
-coresight_find_enabled_sink(struct coresight_device *csdev)
+coresight_find_activated_sysfs_sink(struct coresight_device *csdev)
 {
 	int i;
 	struct coresight_device *sink = NULL;
 
 	if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
 	     csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
-	     csdev->activated)
+	     csdev->sysfs_sink_activated)
 		return csdev;
 
 	/*
@@ -654,7 +660,7 @@ coresight_find_enabled_sink(struct coresight_device *csdev)
 
 		child_dev = csdev->pdata->out_conns[i]->dest_dev;
 		if (child_dev)
-			sink = coresight_find_enabled_sink(child_dev);
+			sink = coresight_find_activated_sysfs_sink(child_dev);
 		if (sink)
 			return sink;
 	}
@@ -662,21 +668,6 @@ coresight_find_enabled_sink(struct coresight_device *csdev)
 	return NULL;
 }
 
-/**
- * coresight_get_enabled_sink - returns the first enabled sink using
- * connection based search starting from the source reference
- *
- * @source: Coresight source device reference
- */
-struct coresight_device *
-coresight_get_enabled_sink(struct coresight_device *source)
-{
-	if (!source)
-		return NULL;
-
-	return coresight_find_enabled_sink(source);
-}
-
 static int coresight_sink_by_id(struct device *dev, const void *data)
 {
 	struct coresight_device *csdev = to_coresight_device(dev);
@@ -810,11 +801,10 @@ static void coresight_drop_device(struct coresight_device *csdev)
  * @sink:	The final sink we want in this path.
  * @path:	The list to add devices to.
  *
- * The tree of Coresight device is traversed until an activated sink is
- * found.  From there the sink is added to the list along with all the
- * devices that led to that point - the end result is a list from source
- * to sink. In that list the source is the first device and the sink the
- * last one.
+ * The tree of Coresight device is traversed until @sink is found.
+ * From there the sink is added to the list along with all the devices that led
+ * to that point - the end result is a list from source to sink. In that list
+ * the source is the first device and the sink the last one.
  */
 static int _coresight_build_path(struct coresight_device *csdev,
 				 struct coresight_device *sink,
@@ -824,7 +814,7 @@ static int _coresight_build_path(struct coresight_device *csdev,
 	bool found = false;
 	struct coresight_node *node;
 
-	/* An activated sink has been found.  Enqueue the element */
+	/* The sink has been found.  Enqueue the element */
 	if (csdev == sink)
 		goto out;
 
@@ -1145,7 +1135,7 @@ int coresight_enable(struct coresight_device *csdev)
 		goto out;
 	}
 
-	sink = coresight_get_enabled_sink(csdev);
+	sink = coresight_find_activated_sysfs_sink(csdev);
 	if (!sink) {
 		ret = -EINVAL;
 		goto out;
@@ -1259,7 +1249,7 @@ static ssize_t enable_sink_show(struct device *dev,
 {
 	struct coresight_device *csdev = to_coresight_device(dev);
 
-	return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->activated);
+	return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->sysfs_sink_activated);
 }
 
 static ssize_t enable_sink_store(struct device *dev,
@@ -1274,10 +1264,7 @@ static ssize_t enable_sink_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	if (val)
-		csdev->activated = true;
-	else
-		csdev->activated = false;
+	csdev->sysfs_sink_activated = !!val;
 
 	return size;
 
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index 30c051055e54..ced5be05a527 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -130,8 +130,6 @@ void coresight_disable_path(struct list_head *path);
 int coresight_enable_path(struct list_head *path, enum cs_mode mode,
 			  void *sink_data);
 struct coresight_device *coresight_get_sink(struct list_head *path);
-struct coresight_device *
-coresight_get_enabled_sink(struct coresight_device *source);
 struct coresight_device *coresight_get_sink_by_id(u32 id);
 struct coresight_device *
 coresight_find_default_sink(struct coresight_device *csdev);
-- 
cgit v1.2.3


From a11ebe138b8ddb119b1b75c143429f64d605a54e Mon Sep 17 00:00:00 2001
From: James Clark <james.clark@arm.com>
Date: Mon, 29 Jan 2024 15:40:34 +0000
Subject: coresight: Remove ops callback checks

The check for the existence of callbacks before using them implies that
this happens and is supported. There are no devices without
enable/disable callbacks, and it wouldn't be possible to add a new
working device without adding them either, so just remove them.

Furthermore, there are more callbacks than just enable and disable that
are already used unguarded in other places.

The comment about new session compatibility doesn't seem to match up to
the line of code that it's on so remove it. I think it's alluding to the
fact that sinks will check if they were already enabled via sysfs or
Perf and fail the enable. But there are more detailed comments at those
places, and this one isn't very useful.

Signed-off-by: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20240129154050.569566-4-james.clark@arm.com
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 drivers/hwtracing/coresight/coresight-core.c | 51 +++++++---------------------
 1 file changed, 12 insertions(+), 39 deletions(-)

(limited to 'drivers/hwtracing')

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 37e59052e877..5e93b52df105 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -279,16 +279,8 @@ EXPORT_SYMBOL_GPL(coresight_add_helper);
 static int coresight_enable_sink(struct coresight_device *csdev,
 				 enum cs_mode mode, void *data)
 {
-	int ret;
-
-	/*
-	 * We need to make sure the "new" session is compatible with the
-	 * existing "mode" of operation.
-	 */
-	if (!sink_ops(csdev)->enable)
-		return -EINVAL;
+	int ret = sink_ops(csdev)->enable(csdev, mode, data);
 
-	ret = sink_ops(csdev)->enable(csdev, mode, data);
 	if (ret)
 		return ret;
 
@@ -299,12 +291,7 @@ static int coresight_enable_sink(struct coresight_device *csdev,
 
 static void coresight_disable_sink(struct coresight_device *csdev)
 {
-	int ret;
-
-	if (!sink_ops(csdev)->disable)
-		return;
-
-	ret = sink_ops(csdev)->disable(csdev);
+	int ret = sink_ops(csdev)->disable(csdev);
 	if (ret)
 		return;
 	csdev->enable = false;
@@ -330,11 +317,9 @@ static int coresight_enable_link(struct coresight_device *csdev,
 	if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT && IS_ERR(outconn))
 		return PTR_ERR(outconn);
 
-	if (link_ops(csdev)->enable) {
-		ret = link_ops(csdev)->enable(csdev, inconn, outconn);
-		if (!ret)
-			csdev->enable = true;
-	}
+	ret = link_ops(csdev)->enable(csdev, inconn, outconn);
+	if (!ret)
+		csdev->enable = true;
 
 	return ret;
 }
@@ -354,9 +339,7 @@ static void coresight_disable_link(struct coresight_device *csdev,
 	outconn = coresight_find_out_connection(csdev, child);
 	link_subtype = csdev->subtype.link_subtype;
 
-	if (link_ops(csdev)->disable) {
-		link_ops(csdev)->disable(csdev, inconn, outconn);
-	}
+	link_ops(csdev)->disable(csdev, inconn, outconn);
 
 	if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG) {
 		for (i = 0; i < csdev->pdata->nr_inconns; i++)
@@ -382,11 +365,9 @@ int coresight_enable_source(struct coresight_device *csdev, enum cs_mode mode,
 	int ret;
 
 	if (!csdev->enable) {
-		if (source_ops(csdev)->enable) {
-			ret = source_ops(csdev)->enable(csdev, data, mode);
-			if (ret)
-				return ret;
-		}
+		ret = source_ops(csdev)->enable(csdev, data, mode);
+		if (ret)
+			return ret;
 		csdev->enable = true;
 	}
 
@@ -404,11 +385,8 @@ static bool coresight_is_helper(struct coresight_device *csdev)
 static int coresight_enable_helper(struct coresight_device *csdev,
 				   enum cs_mode mode, void *data)
 {
-	int ret;
+	int ret = helper_ops(csdev)->enable(csdev, mode, data);
 
-	if (!helper_ops(csdev)->enable)
-		return 0;
-	ret = helper_ops(csdev)->enable(csdev, mode, data);
 	if (ret)
 		return ret;
 
@@ -418,12 +396,8 @@ static int coresight_enable_helper(struct coresight_device *csdev,
 
 static void coresight_disable_helper(struct coresight_device *csdev)
 {
-	int ret;
-
-	if (!helper_ops(csdev)->disable)
-		return;
+	int ret = helper_ops(csdev)->disable(csdev, NULL);
 
-	ret = helper_ops(csdev)->disable(csdev, NULL);
 	if (ret)
 		return;
 	csdev->enable = false;
@@ -453,8 +427,7 @@ static void coresight_disable_helpers(struct coresight_device *csdev)
  */
 void coresight_disable_source(struct coresight_device *csdev, void *data)
 {
-	if (source_ops(csdev)->disable)
-		source_ops(csdev)->disable(csdev, data);
+	source_ops(csdev)->disable(csdev, data);
 	coresight_disable_helpers(csdev);
 }
 EXPORT_SYMBOL_GPL(coresight_disable_source);
-- 
cgit v1.2.3


From 9cae77cf23e317f31de036ced7ad2c261317dc76 Mon Sep 17 00:00:00 2001
From: James Clark <james.clark@arm.com>
Date: Mon, 29 Jan 2024 15:40:35 +0000
Subject: coresight: Move mode to struct coresight_device

Most devices use mode, so move the mode definition out of the individual
devices and up to the Coresight device. This will allow the core code to
also know the mode which will be useful in a later commit.

This also fixes the inconsistency of the documentation of the mode field
on the individual device types. For example ETB10 had "this ETB is being
used".

Two devices didn't require an atomic mode type, so these usages have
been converted to atomic_get() and atomic_set() only to make it compile,
but the documentation of the field in struct coresight_device explains
this type of usage.

In the future, manipulation of the mode could be completely moved out of
the individual devices and into the core code because it's almost all
duplicate code, and this change is a step towards that.

Signed-off-by: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20240129154050.569566-5-james.clark@arm.com
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 drivers/hwtracing/coresight/coresight-etb10.c      | 18 +++++++--------
 drivers/hwtracing/coresight/coresight-etm.h        |  2 --
 drivers/hwtracing/coresight/coresight-etm3x-core.c | 13 +++++------
 .../hwtracing/coresight/coresight-etm3x-sysfs.c    |  4 ++--
 drivers/hwtracing/coresight/coresight-etm4x-core.c | 16 ++++++-------
 drivers/hwtracing/coresight/coresight-etm4x.h      |  1 -
 drivers/hwtracing/coresight/coresight-stm.c        | 20 ++++++++---------
 drivers/hwtracing/coresight/coresight-tmc-core.c   |  2 +-
 drivers/hwtracing/coresight/coresight-tmc-etf.c    | 26 +++++++++++-----------
 drivers/hwtracing/coresight/coresight-tmc-etr.c    | 20 ++++++++---------
 drivers/hwtracing/coresight/coresight-tmc.h        |  2 --
 drivers/hwtracing/coresight/ultrasoc-smb.c         | 13 ++++++-----
 drivers/hwtracing/coresight/ultrasoc-smb.h         |  2 --
 13 files changed, 63 insertions(+), 76 deletions(-)

(limited to 'drivers/hwtracing')

diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
index 05e21cffd33b..145fb815ec1c 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -76,7 +76,6 @@ DEFINE_CORESIGHT_DEVLIST(etb_devs, "etb");
  * @pid:	Process ID of the process being monitored by the session
  *		that is using this component.
  * @buf:	area of memory where ETB buffer content gets sent.
- * @mode:	this ETB is being used.
  * @buffer_depth: size of @buf.
  * @trigger_cntr: amount of words to store after a trigger.
  */
@@ -89,7 +88,6 @@ struct etb_drvdata {
 	local_t			reading;
 	pid_t			pid;
 	u8			*buf;
-	u32			mode;
 	u32			buffer_depth;
 	u32			trigger_cntr;
 };
@@ -150,17 +148,17 @@ static int etb_enable_sysfs(struct coresight_device *csdev)
 	spin_lock_irqsave(&drvdata->spinlock, flags);
 
 	/* Don't messup with perf sessions. */
-	if (drvdata->mode == CS_MODE_PERF) {
+	if (local_read(&csdev->mode) == CS_MODE_PERF) {
 		ret = -EBUSY;
 		goto out;
 	}
 
-	if (drvdata->mode == CS_MODE_DISABLED) {
+	if (local_read(&csdev->mode) == CS_MODE_DISABLED) {
 		ret = etb_enable_hw(drvdata);
 		if (ret)
 			goto out;
 
-		drvdata->mode = CS_MODE_SYSFS;
+		local_set(&csdev->mode, CS_MODE_SYSFS);
 	}
 
 	atomic_inc(&csdev->refcnt);
@@ -181,7 +179,7 @@ static int etb_enable_perf(struct coresight_device *csdev, void *data)
 	spin_lock_irqsave(&drvdata->spinlock, flags);
 
 	/* No need to continue if the component is already in used by sysFS. */
-	if (drvdata->mode == CS_MODE_SYSFS) {
+	if (local_read(&drvdata->csdev->mode) == CS_MODE_SYSFS) {
 		ret = -EBUSY;
 		goto out;
 	}
@@ -216,7 +214,7 @@ static int etb_enable_perf(struct coresight_device *csdev, void *data)
 	if (!ret) {
 		/* Associate with monitored process. */
 		drvdata->pid = pid;
-		drvdata->mode = CS_MODE_PERF;
+		local_set(&drvdata->csdev->mode, CS_MODE_PERF);
 		atomic_inc(&csdev->refcnt);
 	}
 
@@ -362,11 +360,11 @@ static int etb_disable(struct coresight_device *csdev)
 	}
 
 	/* Complain if we (somehow) got out of sync */
-	WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
+	WARN_ON_ONCE(local_read(&csdev->mode) == CS_MODE_DISABLED);
 	etb_disable_hw(drvdata);
 	/* Dissociate from monitored process. */
 	drvdata->pid = -1;
-	drvdata->mode = CS_MODE_DISABLED;
+	local_set(&csdev->mode, CS_MODE_DISABLED);
 	spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
 	dev_dbg(&csdev->dev, "ETB disabled\n");
@@ -589,7 +587,7 @@ static void etb_dump(struct etb_drvdata *drvdata)
 	unsigned long flags;
 
 	spin_lock_irqsave(&drvdata->spinlock, flags);
-	if (drvdata->mode == CS_MODE_SYSFS) {
+	if (local_read(&drvdata->csdev->mode) == CS_MODE_SYSFS) {
 		__etb_disable_hw(drvdata);
 		etb_dump_hw(drvdata);
 		__etb_enable_hw(drvdata);
diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h
index 9a0d08b092ae..e02c3ea972c9 100644
--- a/drivers/hwtracing/coresight/coresight-etm.h
+++ b/drivers/hwtracing/coresight/coresight-etm.h
@@ -215,7 +215,6 @@ struct etm_config {
  * @port_size:	port size as reported by ETMCR bit 4-6 and 21.
  * @arch:	ETM/PTM version number.
  * @use_cpu14:	true if management registers need to be accessed via CP14.
- * @mode:	this tracer's mode, i.e sysFS, Perf or disabled.
  * @sticky_enable: true if ETM base configuration has been done.
  * @boot_enable:true if we should start tracing at boot time.
  * @os_unlock:	true if access to management registers is allowed.
@@ -238,7 +237,6 @@ struct etm_drvdata {
 	int				port_size;
 	u8				arch;
 	bool				use_cp14;
-	local_t				mode;
 	bool				sticky_enable;
 	bool				boot_enable;
 	bool				os_unlock;
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
index 74ae26911b8a..333d0a32c95c 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
@@ -559,7 +559,7 @@ static int etm_enable(struct coresight_device *csdev, struct perf_event *event,
 	u32 val;
 	struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 
-	val = local_cmpxchg(&drvdata->mode, CS_MODE_DISABLED, mode);
+	val = local_cmpxchg(&drvdata->csdev->mode, CS_MODE_DISABLED, mode);
 
 	/* Someone is already using the tracer */
 	if (val)
@@ -578,7 +578,7 @@ static int etm_enable(struct coresight_device *csdev, struct perf_event *event,
 
 	/* The tracer didn't start */
 	if (ret)
-		local_set(&drvdata->mode, CS_MODE_DISABLED);
+		local_set(&drvdata->csdev->mode, CS_MODE_DISABLED);
 
 	return ret;
 }
@@ -672,14 +672,13 @@ static void etm_disable(struct coresight_device *csdev,
 			struct perf_event *event)
 {
 	enum cs_mode mode;
-	struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 
 	/*
 	 * For as long as the tracer isn't disabled another entity can't
 	 * change its status.  As such we can read the status here without
 	 * fearing it will change under us.
 	 */
-	mode = local_read(&drvdata->mode);
+	mode = local_read(&csdev->mode);
 
 	switch (mode) {
 	case CS_MODE_DISABLED:
@@ -696,7 +695,7 @@ static void etm_disable(struct coresight_device *csdev,
 	}
 
 	if (mode)
-		local_set(&drvdata->mode, CS_MODE_DISABLED);
+		local_set(&csdev->mode, CS_MODE_DISABLED);
 }
 
 static const struct coresight_ops_source etm_source_ops = {
@@ -730,7 +729,7 @@ static int etm_starting_cpu(unsigned int cpu)
 		etmdrvdata[cpu]->os_unlock = true;
 	}
 
-	if (local_read(&etmdrvdata[cpu]->mode))
+	if (local_read(&etmdrvdata[cpu]->csdev->mode))
 		etm_enable_hw(etmdrvdata[cpu]);
 	spin_unlock(&etmdrvdata[cpu]->spinlock);
 	return 0;
@@ -742,7 +741,7 @@ static int etm_dying_cpu(unsigned int cpu)
 		return 0;
 
 	spin_lock(&etmdrvdata[cpu]->spinlock);
-	if (local_read(&etmdrvdata[cpu]->mode))
+	if (local_read(&etmdrvdata[cpu]->csdev->mode))
 		etm_disable_hw(etmdrvdata[cpu]);
 	spin_unlock(&etmdrvdata[cpu]->spinlock);
 	return 0;
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
index 2f271b7fb048..6c8429c980b1 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
@@ -722,7 +722,7 @@ static ssize_t cntr_val_show(struct device *dev,
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
 	struct etm_config *config = &drvdata->config;
 
-	if (!local_read(&drvdata->mode)) {
+	if (!local_read(&drvdata->csdev->mode)) {
 		spin_lock(&drvdata->spinlock);
 		for (i = 0; i < drvdata->nr_cntr; i++)
 			ret += sprintf(buf, "counter %d: %x\n",
@@ -941,7 +941,7 @@ static ssize_t seq_curr_state_show(struct device *dev,
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
 	struct etm_config *config = &drvdata->config;
 
-	if (!local_read(&drvdata->mode)) {
+	if (!local_read(&drvdata->csdev->mode)) {
 		val = config->seq_curr_state;
 		goto out;
 	}
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index c5ea808ea662..7ceff627cd95 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -841,9 +841,8 @@ static int etm4_enable(struct coresight_device *csdev, struct perf_event *event,
 {
 	int ret;
 	u32 val;
-	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 
-	val = local_cmpxchg(&drvdata->mode, CS_MODE_DISABLED, mode);
+	val = local_cmpxchg(&csdev->mode, CS_MODE_DISABLED, mode);
 
 	/* Someone is already using the tracer */
 	if (val)
@@ -862,7 +861,7 @@ static int etm4_enable(struct coresight_device *csdev, struct perf_event *event,
 
 	/* The tracer didn't start */
 	if (ret)
-		local_set(&drvdata->mode, CS_MODE_DISABLED);
+		local_set(&csdev->mode, CS_MODE_DISABLED);
 
 	return ret;
 }
@@ -1004,14 +1003,13 @@ static void etm4_disable(struct coresight_device *csdev,
 			 struct perf_event *event)
 {
 	enum cs_mode mode;
-	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 
 	/*
 	 * For as long as the tracer isn't disabled another entity can't
 	 * change its status.  As such we can read the status here without
 	 * fearing it will change under us.
 	 */
-	mode = local_read(&drvdata->mode);
+	mode = local_read(&csdev->mode);
 
 	switch (mode) {
 	case CS_MODE_DISABLED:
@@ -1025,7 +1023,7 @@ static void etm4_disable(struct coresight_device *csdev,
 	}
 
 	if (mode)
-		local_set(&drvdata->mode, CS_MODE_DISABLED);
+		local_set(&csdev->mode, CS_MODE_DISABLED);
 }
 
 static const struct coresight_ops_source etm4_source_ops = {
@@ -1663,7 +1661,7 @@ static int etm4_starting_cpu(unsigned int cpu)
 	if (!etmdrvdata[cpu]->os_unlock)
 		etm4_os_unlock(etmdrvdata[cpu]);
 
-	if (local_read(&etmdrvdata[cpu]->mode))
+	if (local_read(&etmdrvdata[cpu]->csdev->mode))
 		etm4_enable_hw(etmdrvdata[cpu]);
 	spin_unlock(&etmdrvdata[cpu]->spinlock);
 	return 0;
@@ -1675,7 +1673,7 @@ static int etm4_dying_cpu(unsigned int cpu)
 		return 0;
 
 	spin_lock(&etmdrvdata[cpu]->spinlock);
-	if (local_read(&etmdrvdata[cpu]->mode))
+	if (local_read(&etmdrvdata[cpu]->csdev->mode))
 		etm4_disable_hw(etmdrvdata[cpu]);
 	spin_unlock(&etmdrvdata[cpu]->spinlock);
 	return 0;
@@ -1833,7 +1831,7 @@ static int etm4_cpu_save(struct etmv4_drvdata *drvdata)
 	 * Save and restore the ETM Trace registers only if
 	 * the ETM is active.
 	 */
-	if (local_read(&drvdata->mode) && drvdata->save_state)
+	if (local_read(&drvdata->csdev->mode) && drvdata->save_state)
 		ret = __etm4_cpu_save(drvdata);
 	return ret;
 }
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
index da17b6c49b0f..9ea678bc2e8e 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -1016,7 +1016,6 @@ struct etmv4_drvdata {
 	void __iomem			*base;
 	struct coresight_device		*csdev;
 	spinlock_t			spinlock;
-	local_t				mode;
 	int				cpu;
 	u8				arch;
 	u8				nr_pe;
diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
index 891ee64efed8..f7fc645ea7a4 100644
--- a/drivers/hwtracing/coresight/coresight-stm.c
+++ b/drivers/hwtracing/coresight/coresight-stm.c
@@ -119,7 +119,6 @@ DEFINE_CORESIGHT_DEVLIST(stm_devs, "stm");
  * @spinlock:		only one at a time pls.
  * @chs:		the channels accociated to this STM.
  * @stm:		structure associated to the generic STM interface.
- * @mode:		this tracer's mode (enum cs_mode), i.e sysFS, or disabled.
  * @traceid:		value of the current ID for this component.
  * @write_bytes:	Maximus bytes this STM can write at a time.
  * @stmsper:		settings for register STMSPER.
@@ -136,7 +135,6 @@ struct stm_drvdata {
 	spinlock_t		spinlock;
 	struct channel_space	chs;
 	struct stm_data		stm;
-	local_t			mode;
 	u8			traceid;
 	u32			write_bytes;
 	u32			stmsper;
@@ -201,7 +199,7 @@ static int stm_enable(struct coresight_device *csdev, struct perf_event *event,
 	if (mode != CS_MODE_SYSFS)
 		return -EINVAL;
 
-	val = local_cmpxchg(&drvdata->mode, CS_MODE_DISABLED, mode);
+	val = local_cmpxchg(&csdev->mode, CS_MODE_DISABLED, mode);
 
 	/* Someone is already using the tracer */
 	if (val)
@@ -266,7 +264,7 @@ static void stm_disable(struct coresight_device *csdev,
 	 * change its status.  As such we can read the status here without
 	 * fearing it will change under us.
 	 */
-	if (local_read(&drvdata->mode) == CS_MODE_SYSFS) {
+	if (local_read(&csdev->mode) == CS_MODE_SYSFS) {
 		spin_lock(&drvdata->spinlock);
 		stm_disable_hw(drvdata);
 		spin_unlock(&drvdata->spinlock);
@@ -276,7 +274,7 @@ static void stm_disable(struct coresight_device *csdev,
 
 		pm_runtime_put(csdev->dev.parent);
 
-		local_set(&drvdata->mode, CS_MODE_DISABLED);
+		local_set(&csdev->mode, CS_MODE_DISABLED);
 		dev_dbg(&csdev->dev, "STM tracing disabled\n");
 	}
 }
@@ -373,7 +371,7 @@ static long stm_generic_set_options(struct stm_data *stm_data,
 {
 	struct stm_drvdata *drvdata = container_of(stm_data,
 						   struct stm_drvdata, stm);
-	if (!(drvdata && local_read(&drvdata->mode)))
+	if (!(drvdata && local_read(&drvdata->csdev->mode)))
 		return -EINVAL;
 
 	if (channel >= drvdata->numsp)
@@ -408,7 +406,7 @@ static ssize_t notrace stm_generic_packet(struct stm_data *stm_data,
 						   struct stm_drvdata, stm);
 	unsigned int stm_flags;
 
-	if (!(drvdata && local_read(&drvdata->mode)))
+	if (!(drvdata && local_read(&drvdata->csdev->mode)))
 		return -EACCES;
 
 	if (channel >= drvdata->numsp)
@@ -515,7 +513,7 @@ static ssize_t port_select_show(struct device *dev,
 	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
 	unsigned long val;
 
-	if (!local_read(&drvdata->mode)) {
+	if (!local_read(&drvdata->csdev->mode)) {
 		val = drvdata->stmspscr;
 	} else {
 		spin_lock(&drvdata->spinlock);
@@ -541,7 +539,7 @@ static ssize_t port_select_store(struct device *dev,
 	spin_lock(&drvdata->spinlock);
 	drvdata->stmspscr = val;
 
-	if (local_read(&drvdata->mode)) {
+	if (local_read(&drvdata->csdev->mode)) {
 		CS_UNLOCK(drvdata->base);
 		/* Process as per ARM's TRM recommendation */
 		stmsper = readl_relaxed(drvdata->base + STMSPER);
@@ -562,7 +560,7 @@ static ssize_t port_enable_show(struct device *dev,
 	struct stm_drvdata *drvdata = dev_get_drvdata(dev->parent);
 	unsigned long val;
 
-	if (!local_read(&drvdata->mode)) {
+	if (!local_read(&drvdata->csdev->mode)) {
 		val = drvdata->stmsper;
 	} else {
 		spin_lock(&drvdata->spinlock);
@@ -588,7 +586,7 @@ static ssize_t port_enable_store(struct device *dev,
 	spin_lock(&drvdata->spinlock);
 	drvdata->stmsper = val;
 
-	if (local_read(&drvdata->mode)) {
+	if (local_read(&drvdata->csdev->mode)) {
 		CS_UNLOCK(drvdata->base);
 		writel_relaxed(drvdata->stmsper, drvdata->base + STMSPER);
 		CS_LOCK(drvdata->base);
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
index 39bae35d4ffd..e8b2bbed047f 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-core.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
@@ -558,7 +558,7 @@ static void tmc_shutdown(struct amba_device *adev)
 
 	spin_lock_irqsave(&drvdata->spinlock, flags);
 
-	if (drvdata->mode == CS_MODE_DISABLED)
+	if (local_read(&drvdata->csdev->mode) == CS_MODE_DISABLED)
 		goto out;
 
 	if (drvdata->config_type == TMC_CONFIG_TYPE_ETR)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
index 7406b65e2cdd..2a7e516052a2 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
@@ -89,7 +89,7 @@ static void __tmc_etb_disable_hw(struct tmc_drvdata *drvdata)
 	 * When operating in sysFS mode the content of the buffer needs to be
 	 * read before the TMC is disabled.
 	 */
-	if (drvdata->mode == CS_MODE_SYSFS)
+	if (local_read(&drvdata->csdev->mode) == CS_MODE_SYSFS)
 		tmc_etb_dump_hw(drvdata);
 	tmc_disable_hw(drvdata);
 
@@ -205,7 +205,7 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev)
 	 * sink is already enabled no memory is needed and the HW need not be
 	 * touched.
 	 */
-	if (drvdata->mode == CS_MODE_SYSFS) {
+	if (local_read(&csdev->mode) == CS_MODE_SYSFS) {
 		atomic_inc(&csdev->refcnt);
 		goto out;
 	}
@@ -228,7 +228,7 @@ static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev)
 
 	ret = tmc_etb_enable_hw(drvdata);
 	if (!ret) {
-		drvdata->mode = CS_MODE_SYSFS;
+		local_set(&csdev->mode, CS_MODE_SYSFS);
 		atomic_inc(&csdev->refcnt);
 	} else {
 		/* Free up the buffer if we failed to enable */
@@ -262,7 +262,7 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, void *data)
 		 * No need to continue if the ETB/ETF is already operated
 		 * from sysFS.
 		 */
-		if (drvdata->mode == CS_MODE_SYSFS) {
+		if (local_read(&csdev->mode) == CS_MODE_SYSFS) {
 			ret = -EBUSY;
 			break;
 		}
@@ -292,7 +292,7 @@ static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, void *data)
 		if (!ret) {
 			/* Associate with monitored process. */
 			drvdata->pid = pid;
-			drvdata->mode = CS_MODE_PERF;
+			local_set(&csdev->mode, CS_MODE_PERF);
 			atomic_inc(&csdev->refcnt);
 		}
 	} while (0);
@@ -344,11 +344,11 @@ static int tmc_disable_etf_sink(struct coresight_device *csdev)
 	}
 
 	/* Complain if we (somehow) got out of sync */
-	WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
+	WARN_ON_ONCE(local_read(&csdev->mode) == CS_MODE_DISABLED);
 	tmc_etb_disable_hw(drvdata);
 	/* Dissociate from monitored process. */
 	drvdata->pid = -1;
-	drvdata->mode = CS_MODE_DISABLED;
+	local_set(&csdev->mode, CS_MODE_DISABLED);
 
 	spin_unlock_irqrestore(&drvdata->spinlock, flags);
 
@@ -374,7 +374,7 @@ static int tmc_enable_etf_link(struct coresight_device *csdev,
 	if (atomic_read(&csdev->refcnt) == 0) {
 		ret = tmc_etf_enable_hw(drvdata);
 		if (!ret) {
-			drvdata->mode = CS_MODE_SYSFS;
+			local_set(&csdev->mode, CS_MODE_SYSFS);
 			first_enable = true;
 		}
 	}
@@ -403,7 +403,7 @@ static void tmc_disable_etf_link(struct coresight_device *csdev,
 
 	if (atomic_dec_return(&csdev->refcnt) == 0) {
 		tmc_etf_disable_hw(drvdata);
-		drvdata->mode = CS_MODE_DISABLED;
+		local_set(&csdev->mode, CS_MODE_DISABLED);
 		last_disable = true;
 	}
 	spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -483,7 +483,7 @@ static unsigned long tmc_update_etf_buffer(struct coresight_device *csdev,
 		return 0;
 
 	/* This shouldn't happen */
-	if (WARN_ON_ONCE(drvdata->mode != CS_MODE_PERF))
+	if (WARN_ON_ONCE(local_read(&csdev->mode) != CS_MODE_PERF))
 		return 0;
 
 	spin_lock_irqsave(&drvdata->spinlock, flags);
@@ -629,7 +629,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
 	}
 
 	/* Don't interfere if operated from Perf */
-	if (drvdata->mode == CS_MODE_PERF) {
+	if (local_read(&drvdata->csdev->mode) == CS_MODE_PERF) {
 		ret = -EINVAL;
 		goto out;
 	}
@@ -641,7 +641,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
 	}
 
 	/* Disable the TMC if need be */
-	if (drvdata->mode == CS_MODE_SYSFS) {
+	if (local_read(&drvdata->csdev->mode) == CS_MODE_SYSFS) {
 		/* There is no point in reading a TMC in HW FIFO mode */
 		mode = readl_relaxed(drvdata->base + TMC_MODE);
 		if (mode != TMC_MODE_CIRCULAR_BUFFER) {
@@ -673,7 +673,7 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata)
 	spin_lock_irqsave(&drvdata->spinlock, flags);
 
 	/* Re-enable the TMC if need be */
-	if (drvdata->mode == CS_MODE_SYSFS) {
+	if (local_read(&drvdata->csdev->mode) == CS_MODE_SYSFS) {
 		/* There is no point in reading a TMC in HW FIFO mode */
 		mode = readl_relaxed(drvdata->base + TMC_MODE);
 		if (mode != TMC_MODE_CIRCULAR_BUFFER) {
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index af02ba5d5f15..3dc989d4fcab 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -1143,7 +1143,7 @@ static void __tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
 	 * When operating in sysFS mode the content of the buffer needs to be
 	 * read before the TMC is disabled.
 	 */
-	if (drvdata->mode == CS_MODE_SYSFS)
+	if (local_read(&drvdata->csdev->mode) == CS_MODE_SYSFS)
 		tmc_etr_sync_sysfs_buf(drvdata);
 
 	tmc_disable_hw(drvdata);
@@ -1189,7 +1189,7 @@ static struct etr_buf *tmc_etr_get_sysfs_buffer(struct coresight_device *csdev)
 		spin_lock_irqsave(&drvdata->spinlock, flags);
 	}
 
-	if (drvdata->reading || drvdata->mode == CS_MODE_PERF) {
+	if (drvdata->reading || local_read(&csdev->mode) == CS_MODE_PERF) {
 		ret = -EBUSY;
 		goto out;
 	}
@@ -1230,14 +1230,14 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
 	 * sink is already enabled no memory is needed and the HW need not be
 	 * touched, even if the buffer size has changed.
 	 */
-	if (drvdata->mode == CS_MODE_SYSFS) {
+	if (local_read(&csdev->mode) == CS_MODE_SYSFS) {
 		atomic_inc(&csdev->refcnt);
 		goto out;
 	}
 
 	ret = tmc_etr_enable_hw(drvdata, sysfs_buf);
 	if (!ret) {
-		drvdata->mode = CS_MODE_SYSFS;
+		local_set(&csdev->mode, CS_MODE_SYSFS);
 		atomic_inc(&csdev->refcnt);
 	}
 
@@ -1652,7 +1652,7 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data)
 
 	spin_lock_irqsave(&drvdata->spinlock, flags);
 	 /* Don't use this sink if it is already claimed by sysFS */
-	if (drvdata->mode == CS_MODE_SYSFS) {
+	if (local_read(&csdev->mode) == CS_MODE_SYSFS) {
 		rc = -EBUSY;
 		goto unlock_out;
 	}
@@ -1684,7 +1684,7 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data)
 	if (!rc) {
 		/* Associate with monitored process. */
 		drvdata->pid = pid;
-		drvdata->mode = CS_MODE_PERF;
+		local_set(&csdev->mode, CS_MODE_PERF);
 		drvdata->perf_buf = etr_perf->etr_buf;
 		atomic_inc(&csdev->refcnt);
 	}
@@ -1725,11 +1725,11 @@ static int tmc_disable_etr_sink(struct coresight_device *csdev)
 	}
 
 	/* Complain if we (somehow) got out of sync */
-	WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
+	WARN_ON_ONCE(local_read(&csdev->mode) == CS_MODE_DISABLED);
 	tmc_etr_disable_hw(drvdata);
 	/* Dissociate from monitored process. */
 	drvdata->pid = -1;
-	drvdata->mode = CS_MODE_DISABLED;
+	local_set(&csdev->mode, CS_MODE_DISABLED);
 	/* Reset perf specific data */
 	drvdata->perf_buf = NULL;
 
@@ -1777,7 +1777,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
 	}
 
 	/* Disable the TMC if we are trying to read from a running session. */
-	if (drvdata->mode == CS_MODE_SYSFS)
+	if (local_read(&drvdata->csdev->mode) == CS_MODE_SYSFS)
 		__tmc_etr_disable_hw(drvdata);
 
 	drvdata->reading = true;
@@ -1799,7 +1799,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata)
 	spin_lock_irqsave(&drvdata->spinlock, flags);
 
 	/* RE-enable the TMC if need be */
-	if (drvdata->mode == CS_MODE_SYSFS) {
+	if (local_read(&drvdata->csdev->mode) == CS_MODE_SYSFS) {
 		/*
 		 * The trace run will continue with the same allocated trace
 		 * buffer. Since the tracer is still enabled drvdata::buf can't
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 8dcb426ac3e7..cef979c897e6 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -178,7 +178,6 @@ struct etr_buf {
  * @size:	trace buffer size for this TMC (common for all modes).
  * @max_burst_size: The maximum burst size that can be initiated by
  *		TMC-ETR on AXI bus.
- * @mode:	how this TMC is being used.
  * @config_type: TMC variant, must be of type @tmc_config_type.
  * @memwidth:	width of the memory interface databus, in bytes.
  * @trigger_cntr: amount of words to store after a trigger.
@@ -203,7 +202,6 @@ struct tmc_drvdata {
 	u32			len;
 	u32			size;
 	u32			max_burst_size;
-	u32			mode;
 	enum tmc_config_type	config_type;
 	enum tmc_mem_intf_width	memwidth;
 	u32			trigger_cntr;
diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c
index f0b6806202d1..bef633960173 100644
--- a/drivers/hwtracing/coresight/ultrasoc-smb.c
+++ b/drivers/hwtracing/coresight/ultrasoc-smb.c
@@ -207,11 +207,11 @@ static void smb_enable_sysfs(struct coresight_device *csdev)
 {
 	struct smb_drv_data *drvdata = dev_get_drvdata(csdev->dev.parent);
 
-	if (drvdata->mode != CS_MODE_DISABLED)
+	if (local_read(&csdev->mode) != CS_MODE_DISABLED)
 		return;
 
 	smb_enable_hw(drvdata);
-	drvdata->mode = CS_MODE_SYSFS;
+	local_set(&csdev->mode, CS_MODE_SYSFS);
 }
 
 static int smb_enable_perf(struct coresight_device *csdev, void *data)
@@ -234,7 +234,7 @@ static int smb_enable_perf(struct coresight_device *csdev, void *data)
 	if (drvdata->pid == -1) {
 		smb_enable_hw(drvdata);
 		drvdata->pid = pid;
-		drvdata->mode = CS_MODE_PERF;
+		local_set(&csdev->mode, CS_MODE_PERF);
 	}
 
 	return 0;
@@ -253,7 +253,8 @@ static int smb_enable(struct coresight_device *csdev, enum cs_mode mode,
 		return -EBUSY;
 
 	/* Do nothing, the SMB is already enabled as other mode */
-	if (drvdata->mode != CS_MODE_DISABLED && drvdata->mode != mode)
+	if (local_read(&csdev->mode) != CS_MODE_DISABLED &&
+	    local_read(&csdev->mode) != mode)
 		return -EBUSY;
 
 	switch (mode) {
@@ -289,13 +290,13 @@ static int smb_disable(struct coresight_device *csdev)
 		return -EBUSY;
 
 	/* Complain if we (somehow) got out of sync */
-	WARN_ON_ONCE(drvdata->mode == CS_MODE_DISABLED);
+	WARN_ON_ONCE(local_read(&csdev->mode) == CS_MODE_DISABLED);
 
 	smb_disable_hw(drvdata);
 
 	/* Dissociate from the target process. */
 	drvdata->pid = -1;
-	drvdata->mode = CS_MODE_DISABLED;
+	local_set(&csdev->mode, CS_MODE_DISABLED);
 	dev_dbg(&csdev->dev, "Ultrasoc SMB disabled\n");
 
 	return 0;
diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.h b/drivers/hwtracing/coresight/ultrasoc-smb.h
index 82a44c14a882..a91d39cfccb8 100644
--- a/drivers/hwtracing/coresight/ultrasoc-smb.h
+++ b/drivers/hwtracing/coresight/ultrasoc-smb.h
@@ -109,7 +109,6 @@ struct smb_data_buffer {
  * @reading:	Synchronise user space access to SMB buffer.
  * @pid:	Process ID of the process being monitored by the
  *		session that is using this component.
- * @mode:	How this SMB is being used, perf mode or sysfs mode.
  */
 struct smb_drv_data {
 	void __iomem *base;
@@ -119,7 +118,6 @@ struct smb_drv_data {
 	spinlock_t spinlock;
 	bool reading;
 	pid_t pid;
-	enum cs_mode mode;
 };
 
 #endif
-- 
cgit v1.2.3


From d5e83f97eb5669bfdd894ec980083f65517df2fb Mon Sep 17 00:00:00 2001
From: James Clark <james.clark@arm.com>
Date: Mon, 29 Jan 2024 15:40:36 +0000
Subject: coresight: Remove the 'enable' field.

'enable', which probably should have been 'enabled', is only ever read
in the core code in relation to controlling sources, and specifically
only sources in sysfs mode. Confusingly it's not labelled as such and
relying on it can be a source of bugs like the one fixed by
commit 078dbba3f0c9 ("coresight: Fix crash when Perf and sysfs modes are
used concurrently").

Most importantly, it can only be used when the coresight_mutex is held
which is only done when enabling and disabling paths in sysfs mode, and
not Perf mode. So to prevent its usage spreading and leaking out to
other devices, remove it.

It's use is equivalent to checking if the mode is currently sysfs, as
due to the coresight_mutex lock, mode == CS_MODE_SYSFS can only become
true or untrue when that lock is held, and when mode == CS_MODE_SYSFS
the device is both enabled and in sysfs mode.

The one place it was used outside of the core code is in TPDA, but that
pattern is more appropriately represented using refcounts inside the
device's own spinlock.

Signed-off-by: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20240129154050.569566-6-james.clark@arm.com
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 drivers/hwtracing/coresight/coresight-core.c | 86 ++++++++++------------------
 drivers/hwtracing/coresight/coresight-tpda.c | 12 +++-
 2 files changed, 38 insertions(+), 60 deletions(-)

(limited to 'drivers/hwtracing')

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 5e93b52df105..b8d6520d47c9 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -279,29 +279,18 @@ EXPORT_SYMBOL_GPL(coresight_add_helper);
 static int coresight_enable_sink(struct coresight_device *csdev,
 				 enum cs_mode mode, void *data)
 {
-	int ret = sink_ops(csdev)->enable(csdev, mode, data);
-
-	if (ret)
-		return ret;
-
-	csdev->enable = true;
-
-	return 0;
+	return sink_ops(csdev)->enable(csdev, mode, data);
 }
 
 static void coresight_disable_sink(struct coresight_device *csdev)
 {
-	int ret = sink_ops(csdev)->disable(csdev);
-	if (ret)
-		return;
-	csdev->enable = false;
+	sink_ops(csdev)->disable(csdev);
 }
 
 static int coresight_enable_link(struct coresight_device *csdev,
 				 struct coresight_device *parent,
 				 struct coresight_device *child)
 {
-	int ret = 0;
 	int link_subtype;
 	struct coresight_connection *inconn, *outconn;
 
@@ -317,19 +306,13 @@ static int coresight_enable_link(struct coresight_device *csdev,
 	if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT && IS_ERR(outconn))
 		return PTR_ERR(outconn);
 
-	ret = link_ops(csdev)->enable(csdev, inconn, outconn);
-	if (!ret)
-		csdev->enable = true;
-
-	return ret;
+	return link_ops(csdev)->enable(csdev, inconn, outconn);
 }
 
 static void coresight_disable_link(struct coresight_device *csdev,
 				   struct coresight_device *parent,
 				   struct coresight_device *child)
 {
-	int i;
-	int link_subtype;
 	struct coresight_connection *inconn, *outconn;
 
 	if (!parent || !child)
@@ -337,26 +320,8 @@ static void coresight_disable_link(struct coresight_device *csdev,
 
 	inconn = coresight_find_out_connection(parent, csdev);
 	outconn = coresight_find_out_connection(csdev, child);
-	link_subtype = csdev->subtype.link_subtype;
 
 	link_ops(csdev)->disable(csdev, inconn, outconn);
-
-	if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG) {
-		for (i = 0; i < csdev->pdata->nr_inconns; i++)
-			if (atomic_read(&csdev->pdata->in_conns[i]->dest_refcnt) !=
-			    0)
-				return;
-	} else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT) {
-		for (i = 0; i < csdev->pdata->nr_outconns; i++)
-			if (atomic_read(&csdev->pdata->out_conns[i]->src_refcnt) !=
-			    0)
-				return;
-	} else {
-		if (atomic_read(&csdev->refcnt) != 0)
-			return;
-	}
-
-	csdev->enable = false;
 }
 
 int coresight_enable_source(struct coresight_device *csdev, enum cs_mode mode,
@@ -364,11 +329,16 @@ int coresight_enable_source(struct coresight_device *csdev, enum cs_mode mode,
 {
 	int ret;
 
-	if (!csdev->enable) {
+	/*
+	 * Comparison with CS_MODE_SYSFS works without taking any device
+	 * specific spinlock because the truthyness of that comparison can only
+	 * change with coresight_mutex held, which we already have here.
+	 */
+	lockdep_assert_held(&coresight_mutex);
+	if (local_read(&csdev->mode) != CS_MODE_SYSFS) {
 		ret = source_ops(csdev)->enable(csdev, data, mode);
 		if (ret)
 			return ret;
-		csdev->enable = true;
 	}
 
 	atomic_inc(&csdev->refcnt);
@@ -385,22 +355,12 @@ static bool coresight_is_helper(struct coresight_device *csdev)
 static int coresight_enable_helper(struct coresight_device *csdev,
 				   enum cs_mode mode, void *data)
 {
-	int ret = helper_ops(csdev)->enable(csdev, mode, data);
-
-	if (ret)
-		return ret;
-
-	csdev->enable = true;
-	return 0;
+	return helper_ops(csdev)->enable(csdev, mode, data);
 }
 
 static void coresight_disable_helper(struct coresight_device *csdev)
 {
-	int ret = helper_ops(csdev)->disable(csdev, NULL);
-
-	if (ret)
-		return;
-	csdev->enable = false;
+	helper_ops(csdev)->disable(csdev, NULL);
 }
 
 static void coresight_disable_helpers(struct coresight_device *csdev)
@@ -445,11 +405,15 @@ EXPORT_SYMBOL_GPL(coresight_disable_source);
 static bool coresight_disable_source_sysfs(struct coresight_device *csdev,
 					   void *data)
 {
+	lockdep_assert_held(&coresight_mutex);
+	if (local_read(&csdev->mode) != CS_MODE_SYSFS)
+		return false;
+
 	if (atomic_dec_return(&csdev->refcnt) == 0) {
 		coresight_disable_source(csdev, data);
-		csdev->enable = false;
+		return true;
 	}
-	return !csdev->enable;
+	return false;
 }
 
 /*
@@ -1097,7 +1061,13 @@ int coresight_enable(struct coresight_device *csdev)
 	if (ret)
 		goto out;
 
-	if (csdev->enable) {
+	/*
+	 * mode == SYSFS implies that it's already enabled. Don't look at the
+	 * refcount to determine this because we don't claim the source until
+	 * coresight_enable_source() so can still race with Perf mode which
+	 * doesn't hold coresight_mutex.
+	 */
+	if (local_read(&csdev->mode) == CS_MODE_SYSFS) {
 		/*
 		 * There could be multiple applications driving the software
 		 * source. So keep the refcount for each such user when the
@@ -1183,7 +1153,7 @@ void coresight_disable(struct coresight_device *csdev)
 	if (ret)
 		goto out;
 
-	if (!csdev->enable || !coresight_disable_source_sysfs(csdev, NULL))
+	if (!coresight_disable_source_sysfs(csdev, NULL))
 		goto out;
 
 	switch (csdev->subtype.source_subtype) {
@@ -1249,7 +1219,9 @@ static ssize_t enable_source_show(struct device *dev,
 {
 	struct coresight_device *csdev = to_coresight_device(dev);
 
-	return scnprintf(buf, PAGE_SIZE, "%u\n", csdev->enable);
+	guard(mutex)(&coresight_mutex);
+	return scnprintf(buf, PAGE_SIZE, "%u\n",
+			 local_read(&csdev->mode) == CS_MODE_SYSFS);
 }
 
 static ssize_t enable_source_store(struct device *dev,
diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c
index 4ac954f4bc13..c813ec427b8d 100644
--- a/drivers/hwtracing/coresight/coresight-tpda.c
+++ b/drivers/hwtracing/coresight/coresight-tpda.c
@@ -148,7 +148,11 @@ static int __tpda_enable(struct tpda_drvdata *drvdata, int port)
 
 	CS_UNLOCK(drvdata->base);
 
-	if (!drvdata->csdev->enable)
+	/*
+	 * Only do pre-port enable for first po