[PATCH V5 0/4] coresight: trbe: Enable ACPI based devices

[PATCH V5 0/4] coresight: trbe: Enable ACPI based devices

[Anshuman Khandual]

This series enables detection of ACPI based TRBE devices via a stand alone
purpose built representative platform device. But as a pre-requisite this
changes coresight_platform_data structure assignment for the TRBE device.

This series is based on v6.5-rc5 kernel, is also dependent on the following
EDK2 changes posted earlier by Sami.

https://edk2.groups.io/g/devel/message/107239
https://edk2.groups.io/g/devel/message/107241

Changes in V5:

- Detected zeroed parsed GSI as a mismatch but handled all zero scenario
- Changed condition check from 'if (ret < 0)' into a 'if (ret)'
- Dropped pr_warn() message after platform_device_register()

Changes in V4:

https://lore.kernel.org/all/20230808082247.383405-1-anshuman.khandual@arm.com/

- Added in-code comment for arm_trbe_device_probe()
- Reverted back using IS_ENABLED() for SPE PMU platform device
- Replaced #ifdef with IS_ENABLED() for TRBE platform device
- Protected arm_trbe_acpi_match with ACPI_PTR() - preventing a build failure
  when CONFIG_ACPI is not enabled
- Added __maybe_unused for arm_acpi_register_pmu_device() and dropped config
  checks with IS_ENABLED()

Changes in V3:

https://lore.kernel.org/all/20230803055652.1322801-1-anshuman.khandual@arm.com/

- Changed ARMV8_TRBE_PDEV_NAME from "arm-trbe-acpi" into "arm,trbe"
- Dropped local variable 'matched'
- Replaced 'matched' with 'valid gsi' as being already matched once
- Moved find_acpi_cpu_topology_hetero_id() outside conditional check

Changes in V2:

https://lore.kernel.org/all/20230801094052.750416-1-anshuman.khandual@arm.com/

- Refactored arm_spe_acpi_register_device() in a separate patch
- Renamed trbe_acpi_resources as trbe_resources
- Renamed trbe_acpi_dev as trbe_dev

Changes in V1:

https://lore.kernel.org/all/20230728112733.359620-1-anshuman.khandual@arm.com/

Cc: Sami Mujawar <sami.mujawar@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: James Clark <james.clark@arm.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org


Anshuman Khandual (4):
  arm_pmu: acpi: Refactor arm_spe_acpi_register_device()
  arm_pmu: acpi: Add a representative platform device for TRBE
  coresight: trbe: Add a representative coresight_platform_data for TRBE
  coresight: trbe: Enable ACPI based TRBE devices

 arch/arm64/include/asm/acpi.h                |   3 +
 drivers/hwtracing/coresight/coresight-trbe.c |  26 +++-
 drivers/hwtracing/coresight/coresight-trbe.h |   2 +
 drivers/perf/arm_pmu_acpi.c                  | 142 ++++++++++++++-----
 include/linux/perf/arm_pmu.h                 |   1 +
 5 files changed, 132 insertions(+), 42 deletions(-)

-- 
2.25.1

[PATCH V5 1/4] arm_pmu: acpi: Refactor arm_spe_acpi_register_device()

[Anshuman Khandual]

Sanity checking all the GICC tables for same interrupt number, and ensuring
a homogeneous ACPI based machine, could be used for other platform devices
as well. Hence this refactors arm_spe_acpi_register_device() into a common
helper arm_acpi_register_pmu_device().

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Co-developed-by: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 drivers/perf/arm_pmu_acpi.c | 109 +++++++++++++++++++++++-------------
 1 file changed, 69 insertions(+), 40 deletions(-)

diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
index 90815ad762eb..8a44e9e3320b 100644
--- a/drivers/perf/arm_pmu_acpi.c
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -69,6 +69,67 @@ static void arm_pmu_acpi_unregister_irq(int cpu)
 		acpi_unregister_gsi(gsi);
 }
 
+static int __maybe_unused
+arm_acpi_register_pmu_device(struct platform_device *pdev, u8 len,
+			     u16 (*parse_gsi)(struct acpi_madt_generic_interrupt *))
+{
+	int cpu, this_hetid, hetid, irq, ret;
+	u16 this_gsi, gsi = 0;
+
+	/*
+	 * Ensure that platform device must have IORESOURCE_IRQ
+	 * resource to hold gsi interrupt.
+	 */
+	if (pdev->num_resources != 1)
+		return -ENXIO;
+
+	if (pdev->resource[0].flags != IORESOURCE_IRQ)
+		return -ENXIO;
+
+	/*
+	 * Sanity check all the GICC tables for the same interrupt
+	 * number. For now, only support homogeneous ACPI machines.
+	 */
+	for_each_possible_cpu(cpu) {
+		struct acpi_madt_generic_interrupt *gicc;
+
+		gicc = acpi_cpu_get_madt_gicc(cpu);
+		if (gicc->header.length < len)
+			return gsi ? -ENXIO : 0;
+
+		this_gsi = parse_gsi(gicc);
+		this_hetid = find_acpi_cpu_topology_hetero_id(cpu);
+		if (!gsi) {
+			hetid = this_hetid;
+			gsi = this_gsi;
+		} else if (hetid != this_hetid || gsi != this_gsi) {
+			pr_warn("ACPI: %s: must be homogeneous\n", pdev->name);
+			return -ENXIO;
+		}
+	}
+	/*
+	 * This is a special case where no cpu on
+	 * the system has the interrupt and which
+	 * could not have been detected via above
+	 * homogeneous mismatch test.
+	 */
+	if (!this_gsi)
+		return 0;
+
+	irq = acpi_register_gsi(NULL, gsi, ACPI_LEVEL_SENSITIVE, ACPI_ACTIVE_HIGH);
+	if (irq < 0) {
+		pr_warn("ACPI: %s Unable to register interrupt: %d\n", pdev->name, gsi);
+		return -ENXIO;
+	}
+
+	pdev->resource[0].start = irq;
+	ret = platform_device_register(pdev);
+	if (ret)
+		acpi_unregister_gsi(gsi);
+
+	return ret;
+}
+
 #if IS_ENABLED(CONFIG_ARM_SPE_PMU)
 static struct resource spe_resources[] = {
 	{
@@ -84,6 +145,11 @@ static struct platform_device spe_dev = {
 	.num_resources = ARRAY_SIZE(spe_resources)
 };
 
+static u16 arm_spe_parse_gsi(struct acpi_madt_generic_interrupt *gicc)
+{
+	return gicc->spe_interrupt;
+}
+
 /*
  * For lack of a better place, hook the normal PMU MADT walk
  * and create a SPE device if we detect a recent MADT with
@@ -91,47 +157,10 @@ static struct platform_device spe_dev = {
  */
 static void arm_spe_acpi_register_device(void)
 {
-	int cpu, hetid, irq, ret;
-	bool first = true;
-	u16 gsi = 0;
-
-	/*
-	 * Sanity check all the GICC tables for the same interrupt number.
-	 * For now, we only support homogeneous ACPI/SPE machines.
-	 */
-	for_each_possible_cpu(cpu) {
-		struct acpi_madt_generic_interrupt *gicc;
-
-		gicc = acpi_cpu_get_madt_gicc(cpu);
-		if (gicc->header.length < ACPI_MADT_GICC_SPE)
-			return;
-
-		if (first) {
-			gsi = gicc->spe_interrupt;
-			if (!gsi)
-				return;
-			hetid = find_acpi_cpu_topology_hetero_id(cpu);
-			first = false;
-		} else if ((gsi != gicc->spe_interrupt) ||
-			   (hetid != find_acpi_cpu_topology_hetero_id(cpu))) {
-			pr_warn("ACPI: SPE must be homogeneous\n");
-			return;
-		}
-	}
-
-	irq = acpi_register_gsi(NULL, gsi, ACPI_LEVEL_SENSITIVE,
-				ACPI_ACTIVE_HIGH);
-	if (irq < 0) {
-		pr_warn("ACPI: SPE Unable to register interrupt: %d\n", gsi);
-		return;
-	}
-
-	spe_resources[0].start = irq;
-	ret = platform_device_register(&spe_dev);
-	if (ret < 0) {
+	int ret = arm_acpi_register_pmu_device(&spe_dev, ACPI_MADT_GICC_SPE,
+					       arm_spe_parse_gsi);
+	if (ret)
 		pr_warn("ACPI: SPE: Unable to register device\n");
-		acpi_unregister_gsi(gsi);
-	}
 }
 #else
 static inline void arm_spe_acpi_register_device(void)
-- 
2.25.1

[PATCH V5 2/4] arm_pmu: acpi: Add a representative platform device for TRBE

[Anshuman Khandual]

ACPI TRBE does not have a HID for identification which could create and add
a platform device into the platform bus. Also without a platform device, it
cannot be probed and bound to a platform driver.

This creates a dummy platform device for TRBE after ascertaining that ACPI
provides required interrupts uniformly across all cpus on the system. This
device gets created inside drivers/perf/arm_pmu_acpi.c to accommodate TRBE
being built as a module.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 arch/arm64/include/asm/acpi.h |  3 +++
 drivers/perf/arm_pmu_acpi.c   | 35 +++++++++++++++++++++++++++++++++++
 include/linux/perf/arm_pmu.h  |  1 +
 3 files changed, 39 insertions(+)

diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
index bd68e1b7f29f..4d537d56eb84 100644
--- a/arch/arm64/include/asm/acpi.h
+++ b/arch/arm64/include/asm/acpi.h
@@ -42,6 +42,9 @@
 #define ACPI_MADT_GICC_SPE  (offsetof(struct acpi_madt_generic_interrupt, \
 	spe_interrupt) + sizeof(u16))
 
+#define ACPI_MADT_GICC_TRBE  (offsetof(struct acpi_madt_generic_interrupt, \
+	trbe_interrupt) + sizeof(u16))
+
 /* Basic configuration for ACPI */
 #ifdef	CONFIG_ACPI
 pgprot_t __acpi_get_mem_attribute(phys_addr_t addr);
diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c
index 8a44e9e3320b..00fc41bc59f3 100644
--- a/drivers/perf/arm_pmu_acpi.c
+++ b/drivers/perf/arm_pmu_acpi.c
@@ -168,6 +168,40 @@ static inline void arm_spe_acpi_register_device(void)
 }
 #endif /* CONFIG_ARM_SPE_PMU */
 
+#if IS_ENABLED(CONFIG_CORESIGHT_TRBE)
+static struct resource trbe_resources[] = {
+	{
+		/* irq */
+		.flags          = IORESOURCE_IRQ,
+	}
+};
+
+static struct platform_device trbe_dev = {
+	.name = ARMV8_TRBE_PDEV_NAME,
+	.id = -1,
+	.resource = trbe_resources,
+	.num_resources = ARRAY_SIZE(trbe_resources)
+};
+
+static u16 arm_trbe_parse_gsi(struct acpi_madt_generic_interrupt *gicc)
+{
+	return gicc->trbe_interrupt;
+}
+
+static void arm_trbe_acpi_register_device(void)
+{
+	int ret = arm_acpi_register_pmu_device(&trbe_dev, ACPI_MADT_GICC_TRBE,
+					       arm_trbe_parse_gsi);
+	if (ret)
+		pr_warn("ACPI: TRBE: Unable to register device\n");
+}
+#else
+static inline void arm_trbe_acpi_register_device(void)
+{
+
+}
+#endif /* CONFIG_CORESIGHT_TRBE */
+
 static int arm_pmu_acpi_parse_irqs(void)
 {
 	int irq, cpu, irq_cpu, err;
@@ -403,6 +437,7 @@ static int arm_pmu_acpi_init(void)
 		return 0;
 
 	arm_spe_acpi_register_device();
+	arm_trbe_acpi_register_device();
 
 	return 0;
 }
diff --git a/include/linux/perf/arm_pmu.h b/include/linux/perf/arm_pmu.h
index a0801f68762b..143fbc10ecfe 100644
--- a/include/linux/perf/arm_pmu.h
+++ b/include/linux/perf/arm_pmu.h
@@ -187,5 +187,6 @@ void armpmu_free_irq(int irq, int cpu);
 #endif /* CONFIG_ARM_PMU */
 
 #define ARMV8_SPE_PDEV_NAME "arm,spe-v1"
+#define ARMV8_TRBE_PDEV_NAME "arm,trbe"
 
 #endif /* __ARM_PMU_H__ */
-- 
2.25.1

[PATCH V5 3/4] coresight: trbe: Add a representative coresight_platform_data for TRBE

[Anshuman Khandual]

TRBE coresight devices do not need regular connections information, as the
paths get built between all percpu source and their respective percpu sink
devices. Please refer 'commit 2cd87a7b293d ("coresight: core: Add support
for dedicated percpu sinks")' which added support for percpu sink devices.

coresight_register() expect device connections via the platform_data. TRBE
devices do not have any graph connections and thus is empty. With upcoming
ACPI support for TRBE, we do not get a real acpi_device and thus
coresight_get_platform_dat() will end up in failures. Hence this allocates
a zeroed coresight_platform_data structure and assigns that back into the
device.

Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
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
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 drivers/hwtracing/coresight/coresight-trbe.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index 7720619909d6..9455d62ca620 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c
@@ -1494,9 +1494,20 @@ static int arm_trbe_device_probe(struct platform_device *pdev)
 	if (!drvdata)
 		return -ENOMEM;
 
-	pdata = coresight_get_platform_data(dev);
-	if (IS_ERR(pdata))
-		return PTR_ERR(pdata);
+	/*
+	 * TRBE coresight devices do not need regular connections
+	 * information, as the paths get built between all percpu
+	 * source and their respective percpu sink devices. Though
+	 * coresight_register() expect device connections via the
+	 * platform_data, which TRBE devices do not have. As they
+	 * are not real ACPI devices, coresight_get_platform_data()
+	 * ends up failing. Instead let's allocate a dummy zeroed
+	 * coresight_platform_data structure and assign that back
+	 * into the device for that purpose.
+	 */
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata)
+		return -ENOMEM;
 
 	dev_set_drvdata(dev, drvdata);
 	dev->platform_data = pdata;
-- 
2.25.1

[PATCH V5 4/4] coresight: trbe: Enable ACPI based TRBE devices

[Anshuman Khandual]

This detects and enables ACPI based TRBE devices via the dummy platform
device created earlier for this purpose.

Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
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
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 drivers/hwtracing/coresight/coresight-trbe.c | 9 +++++++++
 drivers/hwtracing/coresight/coresight-trbe.h | 2 ++
 2 files changed, 11 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index 9455d62ca620..9c59e2652b20 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c
@@ -1548,7 +1548,16 @@ static const struct of_device_id arm_trbe_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, arm_trbe_of_match);
 
+#ifdef CONFIG_ACPI
+static const struct platform_device_id arm_trbe_acpi_match[] = {
+	{ ARMV8_TRBE_PDEV_NAME, 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, arm_trbe_acpi_match);
+#endif
+
 static struct platform_driver arm_trbe_driver = {
+	.id_table = ACPI_PTR(arm_trbe_acpi_match),
 	.driver	= {
 		.name = DRVNAME,
 		.of_match_table = of_match_ptr(arm_trbe_of_match),
diff --git a/drivers/hwtracing/coresight/coresight-trbe.h b/drivers/hwtracing/coresight/coresight-trbe.h
index 77cbb5c63878..fce1735d5c58 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.h
+++ b/drivers/hwtracing/coresight/coresight-trbe.h
@@ -7,11 +7,13 @@
  *
  * Author: Anshuman Khandual <anshuman.khandual@arm.com>
  */
+#include <linux/acpi.h>
 #include <linux/coresight.h>
 #include <linux/device.h>
 #include <linux/irq.h>
 #include <linux/kernel.h>
 #include <linux/of.h>
+#include <linux/perf/arm_pmu.h>
 #include <linux/platform_device.h>
 #include <linux/smp.h>
 
-- 
2.25.1

Re: [PATCH V5 0/4] coresight: trbe: Enable ACPI based devices

[Will Deacon]

On Thu, 17 Aug 2023 11:24:01 +0530, Anshuman Khandual wrote:
> This series enables detection of ACPI based TRBE devices via a stand alone
> purpose built representative platform device. But as a pre-requisite this
> changes coresight_platform_data structure assignment for the TRBE device.
> 
> This series is based on v6.5-rc5 kernel, is also dependent on the following
> EDK2 changes posted earlier by Sami.
> 
> [...]

Applied to will (for-next/perf), thanks!

[1/4] arm_pmu: acpi: Refactor arm_spe_acpi_register_device()
      https://git.kernel.org/will/c/81e5ee471609
[2/4] arm_pmu: acpi: Add a representative platform device for TRBE
      https://git.kernel.org/will/c/1aa3d0274a4a
[3/4] coresight: trbe: Add a representative coresight_platform_data for TRBE
      https://git.kernel.org/will/c/e926b8e9eb40
[4/4] coresight: trbe: Enable ACPI based TRBE devices
      https://git.kernel.org/will/c/0fb93c5ede13

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev

Re: [PATCH V5 0/4] coresight: trbe: Enable ACPI based devices

[Suzuki K Poulose]

Hi Will

On 18/08/2023 19:04, Will Deacon wrote:
> On Thu, 17 Aug 2023 11:24:01 +0530, Anshuman Khandual wrote:
>> This series enables detection of ACPI based TRBE devices via a stand alone
>> purpose built representative platform device. But as a pre-requisite this
>> changes coresight_platform_data structure assignment for the TRBE device.
>>
>> This series is based on v6.5-rc5 kernel, is also dependent on the following
>> EDK2 changes posted earlier by Sami.
>>
>> [...]
> 
> Applied to will (for-next/perf), thanks!
> 
> [1/4] arm_pmu: acpi: Refactor arm_spe_acpi_register_device()
>        https://git.kernel.org/will/c/81e5ee471609
> [2/4] arm_pmu: acpi: Add a representative platform device for TRBE
>        https://git.kernel.org/will/c/1aa3d0274a4a
> [3/4] coresight: trbe: Add a representative coresight_platform_data for TRBE
>        https://git.kernel.org/will/c/e926b8e9eb40

This will conflict with what I have (already) sent to Greg for
coresight/next. Please let me know how you would like handle it

Suzuki

> [4/4] coresight: trbe: Enable ACPI based TRBE devices
>        https://git.kernel.org/will/c/0fb93c5ede13
> 
> Cheers,

Re: [PATCH V5 0/4] coresight: trbe: Enable ACPI based devices

[Will Deacon]

On Sat, Aug 19, 2023 at 08:36:28AM +0100, Suzuki K Poulose wrote:
> On 18/08/2023 19:04, Will Deacon wrote:
> > On Thu, 17 Aug 2023 11:24:01 +0530, Anshuman Khandual wrote:
> > > This series enables detection of ACPI based TRBE devices via a stand alone
> > > purpose built representative platform device. But as a pre-requisite this
> > > changes coresight_platform_data structure assignment for the TRBE device.
> > > 
> > > This series is based on v6.5-rc5 kernel, is also dependent on the following
> > > EDK2 changes posted earlier by Sami.
> > > 
> > > [...]
> > 
> > Applied to will (for-next/perf), thanks!
> > 
> > [1/4] arm_pmu: acpi: Refactor arm_spe_acpi_register_device()
> >        https://git.kernel.org/will/c/81e5ee471609
> > [2/4] arm_pmu: acpi: Add a representative platform device for TRBE
> >        https://git.kernel.org/will/c/1aa3d0274a4a
> > [3/4] coresight: trbe: Add a representative coresight_platform_data for TRBE
> >        https://git.kernel.org/will/c/e926b8e9eb40
> 
> This will conflict with what I have (already) sent to Greg for
> coresight/next. Please let me know how you would like handle it

Hmm, the rationale behind your change to make the pdata allocation
per-device in ("coresight: trbe: Allocate platform data per device")
confuses me: with Anshuman's change to allocate the pdata using
devm_kzalloc(), there shouldn't be any connections for the coresight
core to trip over, should there?

It would've been nice to know about the conflict earlier, but since I
think you're away this week and we're likely to hit the merge window
next week, I'm going to drop the coresight patches for now.

Will

Re: [PATCH V5 0/4] coresight: trbe: Enable ACPI based devices

[Suzuki K Poulose]

On 21/08/2023 12:28, Will Deacon wrote:
> On Sat, Aug 19, 2023 at 08:36:28AM +0100, Suzuki K Poulose wrote:
>> On 18/08/2023 19:04, Will Deacon wrote:
>>> On Thu, 17 Aug 2023 11:24:01 +0530, Anshuman Khandual wrote:
>>>> This series enables detection of ACPI based TRBE devices via a stand alone
>>>> purpose built representative platform device. But as a pre-requisite this
>>>> changes coresight_platform_data structure assignment for the TRBE device.
>>>>
>>>> This series is based on v6.5-rc5 kernel, is also dependent on the following
>>>> EDK2 changes posted earlier by Sami.
>>>>
>>>> [...]
>>>
>>> Applied to will (for-next/perf), thanks!
>>>
>>> [1/4] arm_pmu: acpi: Refactor arm_spe_acpi_register_device()
>>>         https://git.kernel.org/will/c/81e5ee471609
>>> [2/4] arm_pmu: acpi: Add a representative platform device for TRBE
>>>         https://git.kernel.org/will/c/1aa3d0274a4a
>>> [3/4] coresight: trbe: Add a representative coresight_platform_data for TRBE
>>>         https://git.kernel.org/will/c/e926b8e9eb40
>>
>> This will conflict with what I have (already) sent to Greg for
>> coresight/next. Please let me know how you would like handle it
> 
> Hmm, the rationale behind your change to make the pdata allocation
> per-device in ("coresight: trbe: Allocate platform data per device")
> confuses me: with Anshuman's change to allocate the pdata using
> devm_kzalloc(), there shouldn't be any connections for the coresight
> core to trip over, should there?

Anshuman's patch is working around the problem of "TRBE platform
device with ACPI doesn't have a valid companion device" - this is a 
problem for the acpi_get_coresight_platform_data(). The work
around is to move the "allocation" from coresight_get_platform_data()
to the driver (given we don't need anything else from the ACPI except
the IRQ). That doesn't change *how* it is allocated.
Also please note that, the TRBE driver creates a TRBE coresight_device 
per-CPU and the platform data is shared by all of these devices, which
the coresight core driver doesn't cope with. The other option is to
move the releasing of these platform-data to the individual drivers,
which is quite an invasive change. Or, make the core driver tolerate
a NULL platform data, which is also again invasive. So the merged fix
is correct and is still valid after this patch.

> 
> It would've been nice to know about the conflict earlier, but since I
> think you're away this week and we're likely to hit the merge window
> next week, I'm going to drop the coresight patches for now.

Apologies, I was expecting to queue the changes via coresight tree,
given how it was affecting the tree and was awaiting your Ack. However
I didn't confirm it on the list, which is my mistake.

The other problem was reported and the fix eventually had to
conflict with Anshuman's series, which he was made aware of.
Given, your Ack was missing I hoping that Anshuman could respin
the series with your Ack on top of the fix and eventually queue
that via my tree.

Suzuki

> 
> Will

Re: [PATCH V5 0/4] coresight: trbe: Enable ACPI based devices

[Anshuman Khandual]

On 8/28/23 03:41, Suzuki K Poulose wrote:
> On 21/08/2023 12:28, Will Deacon wrote:
>> On Sat, Aug 19, 2023 at 08:36:28AM +0100, Suzuki K Poulose wrote:
>>> On 18/08/2023 19:04, Will Deacon wrote:
>>>> On Thu, 17 Aug 2023 11:24:01 +0530, Anshuman Khandual wrote:
>>>>> This series enables detection of ACPI based TRBE devices via a stand alone
>>>>> purpose built representative platform device. But as a pre-requisite this
>>>>> changes coresight_platform_data structure assignment for the TRBE device.
>>>>>
>>>>> This series is based on v6.5-rc5 kernel, is also dependent on the following
>>>>> EDK2 changes posted earlier by Sami.
>>>>>
>>>>> [...]
>>>>
>>>> Applied to will (for-next/perf), thanks!
>>>>
>>>> [1/4] arm_pmu: acpi: Refactor arm_spe_acpi_register_device()
>>>>         https://git.kernel.org/will/c/81e5ee471609
>>>> [2/4] arm_pmu: acpi: Add a representative platform device for TRBE
>>>>         https://git.kernel.org/will/c/1aa3d0274a4a
>>>> [3/4] coresight: trbe: Add a representative coresight_platform_data for TRBE
>>>>         https://git.kernel.org/will/c/e926b8e9eb40
>>>
>>> This will conflict with what I have (already) sent to Greg for
>>> coresight/next. Please let me know how you would like handle it
>>
>> Hmm, the rationale behind your change to make the pdata allocation
>> per-device in ("coresight: trbe: Allocate platform data per device")
>> confuses me: with Anshuman's change to allocate the pdata using
>> devm_kzalloc(), there shouldn't be any connections for the coresight
>> core to trip over, should there?
> 
> Anshuman's patch is working around the problem of "TRBE platform
> device with ACPI doesn't have a valid companion device" - this is a problem for the acpi_get_coresight_platform_data(). The work
> around is to move the "allocation" from coresight_get_platform_data()
> to the driver (given we don't need anything else from the ACPI except
> the IRQ). That doesn't change *how* it is allocated.
> Also please note that, the TRBE driver creates a TRBE coresight_device per-CPU and the platform data is shared by all of these devices, which
> the coresight core driver doesn't cope with. The other option is to
> move the releasing of these platform-data to the individual drivers,
> which is quite an invasive change. Or, make the core driver tolerate
> a NULL platform data, which is also again invasive. So the merged fix
> is correct and is still valid after this patch.
> 
>>
>> It would've been nice to know about the conflict earlier, but since I
>> think you're away this week and we're likely to hit the merge window
>> next week, I'm going to drop the coresight patches for now.
> 
> Apologies, I was expecting to queue the changes via coresight tree,
> given how it was affecting the tree and was awaiting your Ack. However
> I didn't confirm it on the list, which is my mistake.
> 
> The other problem was reported and the fix eventually had to
> conflict with Anshuman's series, which he was made aware of.
> Given, your Ack was missing I hoping that Anshuman could respin
> the series with your Ack on top of the fix and eventually queue
> that via my tree.

As Will had picked up the series for arm64 tree, I had assumed that the
conflict fix will be taken care of in the process. Hence did not resend
the series, but it got suddenly dropped.

I am wondering - would it be worth re-spinning the series now fixing the
conflict, does it even have a chance for 6.6-rc1 ? Otherwise, will respin
the series after the merge window is over.

Re: [PATCH V5 0/4] coresight: trbe: Enable ACPI based devices

[Anshuman Khandual]

On 8/18/23 23:34, Will Deacon wrote:
> On Thu, 17 Aug 2023 11:24:01 +0530, Anshuman Khandual wrote:
>> This series enables detection of ACPI based TRBE devices via a stand alone
>> purpose built representative platform device. But as a pre-requisite this
>> changes coresight_platform_data structure assignment for the TRBE device.
>>
>> This series is based on v6.5-rc5 kernel, is also dependent on the following
>> EDK2 changes posted earlier by Sami.
>>
>> [...]
> 
> Applied to will (for-next/perf), thanks!
> 
> [1/4] arm_pmu: acpi: Refactor arm_spe_acpi_register_device()
>       https://git.kernel.org/will/c/81e5ee471609
> [2/4] arm_pmu: acpi: Add a representative platform device for TRBE
>       https://git.kernel.org/will/c/1aa3d0274a4a

It seems like the above two changes are still going in for 6.6-rc1 ? I could
see these in arm64/for-next/core and latest linux-next next-20230825.


> [3/4] coresight: trbe: Add a representative coresight_platform_data for TRBE
>       https://git.kernel.org/will/c/e926b8e9eb40
> [4/4] coresight: trbe: Enable ACPI based TRBE devices
>       https://git.kernel.org/will/c/0fb93c5ede13
> 
> Cheers,

Re: [PATCH V5 0/4] coresight: trbe: Enable ACPI based devices

[Will Deacon]

On Mon, Aug 28, 2023 at 08:11:41AM +0530, Anshuman Khandual wrote:
> 
> 
> On 8/18/23 23:34, Will Deacon wrote:
> > On Thu, 17 Aug 2023 11:24:01 +0530, Anshuman Khandual wrote:
> >> This series enables detection of ACPI based TRBE devices via a stand alone
> >> purpose built representative platform device. But as a pre-requisite this
> >> changes coresight_platform_data structure assignment for the TRBE device.
> >>
> >> This series is based on v6.5-rc5 kernel, is also dependent on the following
> >> EDK2 changes posted earlier by Sami.
> >>
> >> [...]
> > 
> > Applied to will (for-next/perf), thanks!
> > 
> > [1/4] arm_pmu: acpi: Refactor arm_spe_acpi_register_device()
> >       https://git.kernel.org/will/c/81e5ee471609
> > [2/4] arm_pmu: acpi: Add a representative platform device for TRBE
> >       https://git.kernel.org/will/c/1aa3d0274a4a
> 
> It seems like the above two changes are still going in for 6.6-rc1 ? I could
> see these in arm64/for-next/core and latest linux-next next-20230825.

Yes, as I said, I only dropped the coresight bits.

Will

Re: [PATCH V5 0/4] coresight: trbe: Enable ACPI based devices

[Will Deacon]

On Sun, Aug 27, 2023 at 11:11:16PM +0100, Suzuki K Poulose wrote:
> On 21/08/2023 12:28, Will Deacon wrote:
> > Hmm, the rationale behind your change to make the pdata allocation
> > per-device in ("coresight: trbe: Allocate platform data per device")
> > confuses me: with Anshuman's change to allocate the pdata using
> > devm_kzalloc(), there shouldn't be any connections for the coresight
> > core to trip over, should there?
> 
> Anshuman's patch is working around the problem of "TRBE platform
> device with ACPI doesn't have a valid companion device" - this is a problem
> for the acpi_get_coresight_platform_data(). The work
> around is to move the "allocation" from coresight_get_platform_data()
> to the driver (given we don't need anything else from the ACPI except
> the IRQ). That doesn't change *how* it is allocated.
> Also please note that, the TRBE driver creates a TRBE coresight_device
> per-CPU and the platform data is shared by all of these devices, which
> the coresight core driver doesn't cope with. The other option is to
> move the releasing of these platform-data to the individual drivers,
> which is quite an invasive change. Or, make the core driver tolerate
> a NULL platform data, which is also again invasive. So the merged fix
> is correct and is still valid after this patch.

Ah, ok, so the problem with TRBE isn't anything to do with its connections,
but simply because the pdata is shared?

Will

Re: [PATCH V5 0/4] coresight: trbe: Enable ACPI based devices

[Suzuki K Poulose]

On 28/08/2023 22:35, Will Deacon wrote:
> On Sun, Aug 27, 2023 at 11:11:16PM +0100, Suzuki K Poulose wrote:
>> On 21/08/2023 12:28, Will Deacon wrote:
>>> Hmm, the rationale behind your change to make the pdata allocation
>>> per-device in ("coresight: trbe: Allocate platform data per device")
>>> confuses me: with Anshuman's change to allocate the pdata using
>>> devm_kzalloc(), there shouldn't be any connections for the coresight
>>> core to trip over, should there?
>>
>> Anshuman's patch is working around the problem of "TRBE platform
>> device with ACPI doesn't have a valid companion device" - this is a problem
>> for the acpi_get_coresight_platform_data(). The work
>> around is to move the "allocation" from coresight_get_platform_data()
>> to the driver (given we don't need anything else from the ACPI except
>> the IRQ). That doesn't change *how* it is allocated.
>> Also please note that, the TRBE driver creates a TRBE coresight_device
>> per-CPU and the platform data is shared by all of these devices, which
>> the coresight core driver doesn't cope with. The other option is to
>> move the releasing of these platform-data to the individual drivers,
>> which is quite an invasive change. Or, make the core driver tolerate
>> a NULL platform data, which is also again invasive. So the merged fix
>> is correct and is still valid after this patch.
> 
> Ah, ok, so the problem with TRBE isn't anything to do with its connections,
> but simply because the pdata is shared?

Correct, thats an issue outside of the ACPI support. With ACPI, the 
coresight_get_platform_data() can't cope with the TRBE with missing
companion device, that is fixed by Anshuman's patch in this series.

Also, please could you confirm the plan forward for merging this
(next version of course) ?


Cheers
Suzuki

> 
> Will

Re: [PATCH V5 0/4] coresight: trbe: Enable ACPI based devices

[Suzuki K Poulose]

On 28/08/2023 17:30, Will Deacon wrote:
> On Mon, Aug 28, 2023 at 08:11:41AM +0530, Anshuman Khandual wrote:
>>
>>
>> On 8/18/23 23:34, Will Deacon wrote:
>>> On Thu, 17 Aug 2023 11:24:01 +0530, Anshuman Khandual wrote:
>>>> This series enables detection of ACPI based TRBE devices via a stand alone
>>>> purpose built representative platform device. But as a pre-requisite this
>>>> changes coresight_platform_data structure assignment for the TRBE device.
>>>>
>>>> This series is based on v6.5-rc5 kernel, is also dependent on the following
>>>> EDK2 changes posted earlier by Sami.
>>>>
>>>> [...]
>>>
>>> Applied to will (for-next/perf), thanks!
>>>
>>> [1/4] arm_pmu: acpi: Refactor arm_spe_acpi_register_device()
>>>        https://git.kernel.org/will/c/81e5ee471609
>>> [2/4] arm_pmu: acpi: Add a representative platform device for TRBE
>>>        https://git.kernel.org/will/c/1aa3d0274a4a
>>
>> It seems like the above two changes are still going in for 6.6-rc1 ? I could
>> see these in arm64/for-next/core and latest linux-next next-20230825.
> 
> Yes, as I said, I only dropped the coresight bits.

Ok, then I can pick up coresight changes via my tree and push it to Greg.

Suzuki


> 
> Will