[PATCH V6 0/6] coresight: etm4x: Migrate ACPI AMBA devices to platform driver

[PATCH V6 0/6] coresight: etm4x: Migrate ACPI AMBA devices to platform driver

[Anshuman Khandual]

CoreSight ETM4x devices could be accessed either via MMIO (handled via
amba_driver) or CPU system instructions (handled via platform driver). But
this has the following issues :

  - Each new CPU comes up with its own PID and thus we need to keep on
    adding the "known" PIDs to get it working with AMBA driver. While
    the ETM4 architecture (and CoreSight architecture) defines way to
    identify a device as ETM4. Thus older kernels  won't be able to
    "discover" a newer CPU, unless we add the PIDs.

  - With ACPI, the ETM4x devices have the same HID to identify the device
    irrespective of the mode of access. This creates a problem where two
    different drivers (both AMBA based driver and platform driver) would
    hook into the "HID" and could conflict. e.g., if AMBA driver gets
    hold of a non-MMIO device, the probe fails. If we have single driver
    hooked into the given "HID", we could handle them seamlessly,
    irrespective of the mode of access.

  - CoreSight is heavily dependent on the runtime power management. With
    ACPI, amba_driver doesn't get us anywhere with handling the power
    and thus one need to always turn the power ON to use them. Moving to
    platform driver gives us the power management for free.

Due to all of the above, we are moving ACPI MMIO based etm4x devices to be
supported via tha platform driver. The series makes the existing platform
driver generic to handle both type of the access modes. Although existing
AMBA driver would still continue to support DT based etm4x MMIO devices.
Although some problems still remain, such as manually adding PIDs for all
new AMBA DT based devices.

The series applies on 6.5-rc1.

Changes in V6:

- Rebased on 6.5-rc1

Changes in V5:

https://lore.kernel.org/all/20230529062511.52016-1-anshuman.khandual@arm.com/

- Updated the comment for apb clock in drvdata structure
- Updated conditional check in etm4_runtime_suspend/resume()
- Asserted that the APB clock is present and also enabled

Changes in V4:

https://lore.kernel.org/all/20230523044553.1525048-1-anshuman.khandual@arm.com/

- Changed in-code comment in etm4_check_arch_features()
- Re-ordered pm_runtime_disable() in etm4_remove_platform_dev()
- Renamed back etm4_match as etm4_sysreg_match
- Moved back [PATCH 6/6] as [PATCH 5/6]

Changes in V3:

https://lore.kernel.org/all/20230519052149.1367814-1-anshuman.khandual@arm.com/

- Returned from etm4_check_arch_features() for non iomem devices 
- Renamed ETM_DEVTYPE_ETMv4x_ARCH as CS_DEVTYPE_PE_TRACE
- Renamed is_etm4x_devtype() as is_devtype_cpu_trace()
- Added a patch to ignore the absence of graph connections

Changes in V2:

https://lore.kernel.org/all/20230327050537.30861-1-anshuman.khandual@arm.com/

- Enables ACPI etm4x device support in the existing platform driver
- Dropped last two patches from the series
- Dropped redundant 'devarch' checking from is_etm4x_device()
- Renamed updated is_etm4x_device() as is_etm4x_devtype()
- Fixed arguments in fallback stub for etm4_check_arch_features()
- Tagged etm4_dev_pm_ops with etm4_platform_driver
- Updated the comment for coresight_get_enable_apb_pclk() helper
- Updated the comment for new 'pclk' element in struct etm4_drvdata
- Dropped the clock when devm_ioremap_resource() fails
- Convert IS_ERR() into a direct pointer check in etm4_remove_platform_dev()
- Dropped "arm,coresight-etm4x" compatible property from etm4_match[]

Changes in V1:

https://lore.kernel.org/all/20230317030501.1811905-1-anshuman.khandual@arm.com/

Cc: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>
Cc: Steve Clevenger <scclevenger@os.amperecomputing.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Russell King (Oracle) <linux@armlinux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: devicetree@vger.kernel.org
Cc: linux-acpi@vger.kernel.org
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org

Anshuman Khandual (4):
  coresight: etm4x: Allocate and device assign 'struct etmv4_drvdata' earlier
  coresight: etm4x: Drop iomem 'base' argument from etm4_probe()
  coresight: etm4x: Drop pid argument from etm4_probe()
  coresight: etm4x: Change etm4_platform_driver driver for MMIO devices

Suzuki K Poulose (2):
  coresight: platform: acpi: Ignore the absence of graph
  coresight: etm4x: Add ACPI support in platform driver

 drivers/acpi/acpi_amba.c                      |   1 -
 .../coresight/coresight-etm4x-core.c          | 118 ++++++++++++++----
 drivers/hwtracing/coresight/coresight-etm4x.h |   4 +
 .../hwtracing/coresight/coresight-platform.c  |   6 +-
 include/linux/coresight.h                     |  59 +++++++++
 5 files changed, 164 insertions(+), 24 deletions(-)

-- 
2.25.1

[PATCH V6 1/6] coresight: etm4x: Allocate and device assign 'struct etmv4_drvdata' earlier

[Anshuman Khandual]

Allocate and device assign 'struct etmv4_drvdata' earlier during the driver
probe, ensuring that it can be retrieved in power management based runtime
callbacks if required. This will also help in dropping iomem base address
argument from the function etm4_probe() later.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
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>
---
 .../coresight/coresight-etm4x-core.c          | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 7e307022303a..264242ba345b 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -2046,17 +2046,14 @@ static int etm4_add_coresight_dev(struct etm4_init_arg *init_arg)
 
 static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid)
 {
-	struct etmv4_drvdata *drvdata;
+	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev);
 	struct csdev_access access = { 0 };
 	struct etm4_init_arg init_arg = { 0 };
 	struct etm4_init_arg *delayed;
 
-	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
-	if (!drvdata)
+	if (WARN_ON(!drvdata))
 		return -ENOMEM;
 
-	dev_set_drvdata(dev, drvdata);
-
 	if (pm_save_enable == PARAM_PM_SAVE_FIRMWARE)
 		pm_save_enable = coresight_loses_context_with_cpu(dev) ?
 			       PARAM_PM_SAVE_SELF_HOSTED : PARAM_PM_SAVE_NEVER;
@@ -2108,6 +2105,7 @@ static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid)
 
 static int etm4_probe_amba(struct amba_device *adev, const struct amba_id *id)
 {
+	struct etmv4_drvdata *drvdata;
 	void __iomem *base;
 	struct device *dev = &adev->dev;
 	struct resource *res = &adev->res;
@@ -2118,6 +2116,11 @@ static int etm4_probe_amba(struct amba_device *adev, const struct amba_id *id)
 	if (IS_ERR(base))
 		return PTR_ERR(base);
 
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, drvdata);
 	ret = etm4_probe(dev, base, id->id);
 	if (!ret)
 		pm_runtime_put(&adev->dev);
@@ -2127,8 +2130,14 @@ static int etm4_probe_amba(struct amba_device *adev, const struct amba_id *id)
 
 static int etm4_probe_platform_dev(struct platform_device *pdev)
 {
+	struct etmv4_drvdata *drvdata;
 	int ret;
 
+	drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	dev_set_drvdata(&pdev->dev, drvdata);
 	pm_runtime_get_noresume(&pdev->dev);
 	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
-- 
2.25.1

[PATCH V6 2/6] coresight: etm4x: Drop iomem 'base' argument from etm4_probe()

[Anshuman Khandual]

'struct etm4_drvdata' itself can carry the base address before etm4_probe()
gets called. Just drop that redundant argument from etm4_probe().

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 drivers/hwtracing/coresight/coresight-etm4x-core.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 264242ba345b..bf93147c23ca 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -2044,7 +2044,7 @@ static int etm4_add_coresight_dev(struct etm4_init_arg *init_arg)
 	return 0;
 }
 
-static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid)
+static int etm4_probe(struct device *dev, u32 etm_pid)
 {
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev);
 	struct csdev_access access = { 0 };
@@ -2065,8 +2065,6 @@ static int etm4_probe(struct device *dev, void __iomem *base, u32 etm_pid)
 			return -ENOMEM;
 	}
 
-	drvdata->base = base;
-
 	spin_lock_init(&drvdata->spinlock);
 
 	drvdata->cpu = coresight_get_cpu(dev);
@@ -2120,8 +2118,9 @@ static int etm4_probe_amba(struct amba_device *adev, const struct amba_id *id)
 	if (!drvdata)
 		return -ENOMEM;
 
+	drvdata->base = base;
 	dev_set_drvdata(dev, drvdata);
-	ret = etm4_probe(dev, base, id->id);
+	ret = etm4_probe(dev, id->id);
 	if (!ret)
 		pm_runtime_put(&adev->dev);
 
@@ -2137,6 +2136,7 @@ static int etm4_probe_platform_dev(struct platform_device *pdev)
 	if (!drvdata)
 		return -ENOMEM;
 
+	drvdata->base = NULL;
 	dev_set_drvdata(&pdev->dev, drvdata);
 	pm_runtime_get_noresume(&pdev->dev);
 	pm_runtime_set_active(&pdev->dev);
@@ -2147,7 +2147,7 @@ static int etm4_probe_platform_dev(struct platform_device *pdev)
 	 * HW by reading appropriate registers on the HW
 	 * and thus we could skip the PID.
 	 */
-	ret = etm4_probe(&pdev->dev, NULL, 0);
+	ret = etm4_probe(&pdev->dev, 0);
 
 	pm_runtime_put(&pdev->dev);
 	return ret;
-- 
2.25.1

[PATCH V6 3/6] coresight: etm4x: Drop pid argument from etm4_probe()

[Anshuman Khandual]

Coresight device pid can be retrieved from its iomem base address, which is
stored in 'struct etm4x_drvdata'. This drops pid argument from etm4_probe()
and 'struct etm4_init_arg'. Instead etm4_check_arch_features() derives the
coresight device pid with a new helper coresight_get_pid(), right before it
is consumed in etm4_hisi_match_pid().

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
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>
---
 .../coresight/coresight-etm4x-core.c          | 29 ++++++++++---------
 include/linux/coresight.h                     | 12 ++++++++
 2 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index bf93147c23ca..e91e59ecec53 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -66,7 +66,6 @@ static u64 etm4_get_access_type(struct etmv4_config *config);
 static enum cpuhp_state hp_online;
 
 struct etm4_init_arg {
-	unsigned int		pid;
 	struct device		*dev;
 	struct csdev_access	*csa;
 };
@@ -370,9 +369,17 @@ static void etm4_disable_arch_specific(struct etmv4_drvdata *drvdata)
 }
 
 static void etm4_check_arch_features(struct etmv4_drvdata *drvdata,
-				      unsigned int id)
+				     struct csdev_access *csa)
 {
-	if (etm4_hisi_match_pid(id))
+	/*
+	 * TRCPIDR* registers are not required for ETMs with system
+	 * instructions. They must be identified by the MIDR+REVIDRs.
+	 * Skip the TRCPID checks for now.
+	 */
+	if (!csa->io_mem)
+		return;
+
+	if (etm4_hisi_match_pid(coresight_get_pid(csa)))
 		set_bit(ETM4_IMPDEF_HISI_CORE_COMMIT, drvdata->arch_features);
 }
 #else
@@ -385,7 +392,7 @@ static void etm4_disable_arch_specific(struct etmv4_drvdata *drvdata)
 }
 
 static void etm4_check_arch_features(struct etmv4_drvdata *drvdata,
-				     unsigned int id)
+				     struct csdev_access *csa)
 {
 }
 #endif /* CONFIG_ETM4X_IMPDEF_FEATURE */
@@ -1161,7 +1168,7 @@ static void etm4_init_arch_data(void *info)
 	etm4_os_unlock_csa(drvdata, csa);
 	etm4_cs_unlock(drvdata, csa);
 
-	etm4_check_arch_features(drvdata, init_arg->pid);
+	etm4_check_arch_features(drvdata, csa);
 
 	/* find all capabilities of the tracing unit */
 	etmidr0 = etm4x_relaxed_read32(csa, TRCIDR0);
@@ -2044,7 +2051,7 @@ static int etm4_add_coresight_dev(struct etm4_init_arg *init_arg)
 	return 0;
 }
 
-static int etm4_probe(struct device *dev, u32 etm_pid)
+static int etm4_probe(struct device *dev)
 {
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev);
 	struct csdev_access access = { 0 };
@@ -2073,7 +2080,6 @@ static int etm4_probe(struct device *dev, u32 etm_pid)
 
 	init_arg.dev = dev;
 	init_arg.csa = &access;
-	init_arg.pid = etm_pid;
 
 	/*
 	 * Serialize against CPUHP callbacks to avoid race condition
@@ -2120,7 +2126,7 @@ static int etm4_probe_amba(struct amba_device *adev, const struct amba_id *id)
 
 	drvdata->base = base;
 	dev_set_drvdata(dev, drvdata);
-	ret = etm4_probe(dev, id->id);
+	ret = etm4_probe(dev);
 	if (!ret)
 		pm_runtime_put(&adev->dev);
 
@@ -2142,12 +2148,7 @@ static int etm4_probe_platform_dev(struct platform_device *pdev)
 	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
 
-	/*
-	 * System register based devices could match the
-	 * HW by reading appropriate registers on the HW
-	 * and thus we could skip the PID.
-	 */
-	ret = etm4_probe(&pdev->dev, 0);
+	ret = etm4_probe(&pdev->dev);
 
 	pm_runtime_put(&pdev->dev);
 	return ret;
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index bf70987240e4..255cfd283883 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -386,6 +386,18 @@ static inline u32 csdev_access_relaxed_read32(struct csdev_access *csa,
 	return csa->read(offset, true, false);
 }
 
+#define CORESIGHT_PIDRn(i)	(0xFE0 + ((i) * 4))
+
+static inline u32 coresight_get_pid(struct csdev_access *csa)
+{
+	u32 i, pid = 0;
+
+	for (i = 0; i < 4; i++)
+		pid |= csdev_access_relaxed_read32(csa, CORESIGHT_PIDRn(i)) << (i * 8);
+
+	return pid;
+}
+
 static inline u64 csdev_access_relaxed_read_pair(struct csdev_access *csa,
 						 u32 lo_offset, u32 hi_offset)
 {
-- 
2.25.1

[PATCH V6 4/6] coresight: etm4x: Change etm4_platform_driver driver for MMIO devices

[Anshuman Khandual]

Add support for handling MMIO based devices via platform driver. We need to
make sure that :

1) The APB clock, if present is enabled at probe and via runtime_pm ops
2) Use the ETM4x architecture or CoreSight architecture registers to
   identify a device as CoreSight ETM4x, instead of relying a white list of
   "Peripheral IDs"

The driver doesn't get to handle the devices yet, until we wire the ACPI
changes to move the devices to be handled via platform driver than the
etm4_amba driver.

Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 .../coresight/coresight-etm4x-core.c          | 58 ++++++++++++++++++-
 drivers/hwtracing/coresight/coresight-etm4x.h |  4 ++
 include/linux/coresight.h                     | 47 +++++++++++++++
 3 files changed, 107 insertions(+), 2 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index e91e59ecec53..43f583987250 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -30,6 +30,7 @@
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/property.h>
+#include <linux/clk/clk-conf.h>
 
 #include <asm/barrier.h>
 #include <asm/sections.h>
@@ -1073,11 +1074,21 @@ static bool etm4_init_sysreg_access(struct etmv4_drvdata *drvdata,
 	return true;
 }
 
+static bool is_devtype_cpu_trace(void __iomem *base)
+{
+	u32 devtype = readl(base + TRCDEVTYPE);
+
+	return (devtype == CS_DEVTYPE_PE_TRACE);
+}
+
 static bool etm4_init_iomem_access(struct etmv4_drvdata *drvdata,
 				   struct csdev_access *csa)
 {
 	u32 devarch = readl_relaxed(drvdata->base + TRCDEVARCH);
 
+	if (!is_coresight_device(drvdata->base) || !is_devtype_cpu_trace(drvdata->base))
+		return false;
+
 	/*
 	 * All ETMs must implement TRCDEVARCH to indicate that
 	 * the component is an ETMv4. Even though TRCIDR1 also
@@ -2135,6 +2146,7 @@ static int etm4_probe_amba(struct amba_device *adev, const struct amba_id *id)
 
 static int etm4_probe_platform_dev(struct platform_device *pdev)
 {
+	struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	struct etmv4_drvdata *drvdata;
 	int ret;
 
@@ -2142,7 +2154,18 @@ static int etm4_probe_platform_dev(struct platform_device *pdev)
 	if (!drvdata)
 		return -ENOMEM;
 
-	drvdata->base = NULL;
+	drvdata->pclk = coresight_get_enable_apb_pclk(&pdev->dev);
+	if (IS_ERR(drvdata->pclk))
+		return -ENODEV;
+
+	if (res) {
+		drvdata->base = devm_ioremap_resource(&pdev->dev, res);
+		if (IS_ERR(drvdata->base)) {
+			clk_put(drvdata->pclk);
+			return PTR_ERR(drvdata->base);
+		}
+	}
+
 	dev_set_drvdata(&pdev->dev, drvdata);
 	pm_runtime_get_noresume(&pdev->dev);
 	pm_runtime_set_active(&pdev->dev);
@@ -2188,7 +2211,7 @@ static struct amba_cs_uci_id uci_id_etm4[] = {
 		/*  ETMv4 UCI data */
 		.devarch	= ETM_DEVARCH_ETMv4x_ARCH,
 		.devarch_mask	= ETM_DEVARCH_ID_MASK,
-		.devtype	= 0x00000013,
+		.devtype	= CS_DEVTYPE_PE_TRACE,
 	}
 };
 
@@ -2244,6 +2267,10 @@ static int __exit etm4_remove_platform_dev(struct platform_device *pdev)
 	if (drvdata)
 		etm4_remove_dev(drvdata);
 	pm_runtime_disable(&pdev->dev);
+
+	if (drvdata->pclk)
+		clk_put(drvdata->pclk);
+
 	return 0;
 }
 
@@ -2288,6 +2315,32 @@ static struct amba_driver etm4x_amba_driver = {
 	.id_table	= etm4_ids,
 };
 
+#ifdef CONFIG_PM
+static int etm4_runtime_suspend(struct device *dev)
+{
+	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev);
+
+	if (drvdata->pclk && !IS_ERR(drvdata->pclk))
+		clk_disable_unprepare(drvdata->pclk);
+
+	return 0;
+}
+
+static int etm4_runtime_resume(struct device *dev)
+{
+	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev);
+
+	if (drvdata->pclk && !IS_ERR(drvdata->pclk))
+		clk_prepare_enable(drvdata->pclk);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops etm4_dev_pm_ops = {
+	SET_RUNTIME_PM_OPS(etm4_runtime_suspend, etm4_runtime_resume, NULL)
+};
+
 static const struct of_device_id etm4_sysreg_match[] = {
 	{ .compatible	= "arm,coresight-etm4x-sysreg" },
 	{ .compatible	= "arm,embedded-trace-extension" },
@@ -2301,6 +2354,7 @@ static struct platform_driver etm4_platform_driver = {
 		.name			= "coresight-etm4x",
 		.of_match_table		= etm4_sysreg_match,
 		.suppress_bind_attrs	= true,
+		.pm			= &etm4_dev_pm_ops,
 	},
 };
 
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
index 27c8a9901868..20e2e4cb7614 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -701,6 +701,8 @@
 #define ETM_DEVARCH_ETE_ARCH						\
 	(ETM_DEVARCH_ARCHITECT_ARM | ETM_DEVARCH_ARCHID_ETE | ETM_DEVARCH_PRESENT)
 
+#define CS_DEVTYPE_PE_TRACE		0x00000013
+
 #define TRCSTATR_IDLE_BIT		0
 #define TRCSTATR_PMSTABLE_BIT		1
 #define ETM_DEFAULT_ADDR_COMP		0
@@ -944,6 +946,7 @@ struct etmv4_save_state {
 
 /**
  * struct etm4_drvdata - specifics associated to an ETM component
+ * @pclk        APB clock if present, otherwise NULL
  * @base:       Memory mapped base address for this component.
  * @csdev:      Component vitals needed by the framework.
  * @spinlock:   Only one at a time pls.
@@ -1009,6 +1012,7 @@ struct etmv4_save_state {
  * @arch_features: Bitmap of arch features of etmv4 devices.
  */
 struct etmv4_drvdata {
+	struct clk			*pclk;
 	void __iomem			*base;
 	struct coresight_device		*csdev;
 	spinlock_t			spinlock;
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 255cfd283883..a269fffaf991 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -6,6 +6,8 @@
 #ifndef _LINUX_CORESIGHT_H
 #define _LINUX_CORESIGHT_H
 
+#include <linux/amba/bus.h>
+#include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/io.h>
 #include <linux/perf_event.h>
@@ -386,6 +388,51 @@ static inline u32 csdev_access_relaxed_read32(struct csdev_access *csa,
 	return csa->read(offset, true, false);
 }
 
+#define CORESIGHT_CIDRn(i)	(0xFF0 + ((i) * 4))
+
+static inline u32 coresight_get_cid(void __iomem *base)
+{
+	u32 i, cid = 0;
+
+	for (i = 0; i < 4; i++)
+		cid |= readl(base + CORESIGHT_CIDRn(i)) << (i * 8);
+
+	return cid;
+}
+
+static inline bool is_coresight_device(void __iomem *base)
+{
+	u32 cid = coresight_get_cid(base);
+
+	return cid == CORESIGHT_CID;
+}
+
+/*
+ * Attempt to find and enable "APB clock" for the given device
+ *
+ * Returns:
+ *
+ * clk   - Clock is found and enabled
+ * NULL  - clock is not found
+ * ERROR - Clock is found but failed to enable
+ */
+static inline struct clk *coresight_get_enable_apb_pclk(struct device *dev)
+{
+	struct clk *pclk;
+	int ret;
+
+	pclk = clk_get(dev, "apb_pclk");
+	if (IS_ERR(pclk))
+		return NULL;
+
+	ret = clk_prepare_enable(pclk);
+	if (ret) {
+		clk_put(pclk);
+		return ERR_PTR(ret);
+	}
+	return pclk;
+}
+
 #define CORESIGHT_PIDRn(i)	(0xFE0 + ((i) * 4))
 
 static inline u32 coresight_get_pid(struct csdev_access *csa)
-- 
2.25.1

[PATCH V6 5/6] coresight: platform: acpi: Ignore the absence of graph

[Anshuman Khandual]

From: Suzuki K Poulose <suzuki.poulose@arm.com>

Some components may not have graph connections for describing
the trace path. e.g., ETE, where it could directly use the per
CPU TRBE. Ignore the absence of graph connections

Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 drivers/hwtracing/coresight/coresight-platform.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
index 3e2e135cb8f6..c8940314cceb 100644
--- a/drivers/hwtracing/coresight/coresight-platform.c
+++ b/drivers/hwtracing/coresight/coresight-platform.c
@@ -669,8 +669,12 @@ static int acpi_coresight_parse_graph(struct device *dev,
 	struct coresight_connection *new_conn;
 
 	graph = acpi_get_coresight_graph(adev);
+	/*
+	 * There are no graph connections, which is fine for some components.
+	 * e.g., ETE
+	 */
 	if (!graph)
-		return -ENOENT;
+		return 0;
 
 	nlinks = graph->package.elements[2].integer.value;
 	if (!nlinks)
-- 
2.25.1

[PATCH V6 6/6] coresight: etm4x: Add ACPI support in platform driver

[Anshuman Khandual]

From: Suzuki K Poulose <suzuki.poulose@arm.com>

Drop ETM4X ACPI ID from the AMBA ACPI device list, and instead just move it
inside the new ACPI devices list detected and used via platform driver.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: linux-acpi@vger.kernel.org
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> (for ACPI specific changes)
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
 drivers/acpi/acpi_amba.c                           |  1 -
 drivers/hwtracing/coresight/coresight-etm4x-core.c | 10 ++++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/acpi_amba.c b/drivers/acpi/acpi_amba.c
index f5b443ab01c2..099966cbac5a 100644
--- a/drivers/acpi/acpi_amba.c
+++ b/drivers/acpi/acpi_amba.c
@@ -22,7 +22,6 @@
 static const struct acpi_device_id amba_id_list[] = {
 	{"ARMH0061", 0}, /* PL061 GPIO Device */
 	{"ARMH0330", 0}, /* ARM DMA Controller DMA-330 */
-	{"ARMHC500", 0}, /* ARM CoreSight ETM4x */
 	{"ARMHC501", 0}, /* ARM CoreSight ETR */
 	{"ARMHC502", 0}, /* ARM CoreSight STM */
 	{"ARMHC503", 0}, /* ARM CoreSight Debug */
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 43f583987250..703b6fcbb6a5 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -3,6 +3,7 @@
  * Copyright (c) 2014, The Linux Foundation. All rights reserved.
  */
 
+#include <linux/acpi.h>
 #include <linux/bitops.h>
 #include <linux/kernel.h>
 #include <linux/moduleparam.h>
@@ -2347,12 +2348,21 @@ 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 */
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, etm4x_acpi_ids);
+#endif
+
 static struct platform_driver etm4_platform_driver = {
 	.probe		= etm4_probe_platform_dev,
 	.remove		= etm4_remove_platform_dev,
 	.driver			= {
 		.name			= "coresight-etm4x",
 		.of_match_table		= etm4_sysreg_match,
+		.acpi_match_table	= ACPI_PTR(etm4x_acpi_ids),
 		.suppress_bind_attrs	= true,
 		.pm			= &etm4_dev_pm_ops,
 	},
-- 
2.25.1

Re: [PATCH V6 6/6] coresight: etm4x: Add ACPI support in platform driver

[Suzuki K Poulose]

Rafael, Len

On 10/07/2023 07:25, Anshuman Khandual wrote:
> From: Suzuki K Poulose <suzuki.poulose@arm.com>
> 
> Drop ETM4X ACPI ID from the AMBA ACPI device list, and instead just move it
> inside the new ACPI devices list detected and used via platform driver.
> 
> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> Cc: Len Brown <lenb@kernel.org>
> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
> Cc: Mike Leach <mike.leach@linaro.org>
> Cc: Leo Yan <leo.yan@linaro.org>
> Cc: Sudeep Holla <sudeep.holla@arm.com>
> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
> Cc: linux-acpi@vger.kernel.org
> Cc: coresight@lists.linaro.org
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> (for ACPI specific changes)
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>

We would like to queue this via coresight tree. The acpi_amba bits have
been reviewed by Sudeep. Please could you give us an Ack, if you are
happy with the proposal ?

Kind regards
Suzuki


> ---
>   drivers/acpi/acpi_amba.c                           |  1 -
>   drivers/hwtracing/coresight/coresight-etm4x-core.c | 10 ++++++++++
>   2 files changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/acpi/acpi_amba.c b/drivers/acpi/acpi_amba.c
> index f5b443ab01c2..099966cbac5a 100644
> --- a/drivers/acpi/acpi_amba.c
> +++ b/drivers/acpi/acpi_amba.c
> @@ -22,7 +22,6 @@
>   static const struct acpi_device_id amba_id_list[] = {
>   	{"ARMH0061", 0}, /* PL061 GPIO Device */
>   	{"ARMH0330", 0}, /* ARM DMA Controller DMA-330 */
> -	{"ARMHC500", 0}, /* ARM CoreSight ETM4x */
>   	{"ARMHC501", 0}, /* ARM CoreSight ETR */
>   	{"ARMHC502", 0}, /* ARM CoreSight STM */
>   	{"ARMHC503", 0}, /* ARM CoreSight Debug */
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> index 43f583987250..703b6fcbb6a5 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> @@ -3,6 +3,7 @@
>    * Copyright (c) 2014, The Linux Foundation. All rights reserved.
>    */
>   
> +#include <linux/acpi.h>
>   #include <linux/bitops.h>
>   #include <linux/kernel.h>
>   #include <linux/moduleparam.h>
> @@ -2347,12 +2348,21 @@ 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 */
> +	{}
> +};
> +MODULE_DEVICE_TABLE(acpi, etm4x_acpi_ids);
> +#endif
> +
>   static struct platform_driver etm4_platform_driver = {
>   	.probe		= etm4_probe_platform_dev,
>   	.remove		= etm4_remove_platform_dev,
>   	.driver			= {
>   		.name			= "coresight-etm4x",
>   		.of_match_table		= etm4_sysreg_match,
> +		.acpi_match_table	= ACPI_PTR(etm4x_acpi_ids),
>   		.suppress_bind_attrs	= true,
>   		.pm			= &etm4_dev_pm_ops,
>   	},

Re: [PATCH V6 6/6] coresight: etm4x: Add ACPI support in platform driver

[Suzuki K Poulose]

Rafael, Len

Ping (packets 6, lost 100%).


On 10/07/2023 17:40, Suzuki K Poulose wrote:
> Rafael, Len
> 
> On 10/07/2023 07:25, Anshuman Khandual wrote:
>> From: Suzuki K Poulose <suzuki.poulose@arm.com>
>>
>> Drop ETM4X ACPI ID from the AMBA ACPI device list, and instead just 
>> move it
>> inside the new ACPI devices list detected and used via platform driver.
>>
>> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
>> Cc: Len Brown <lenb@kernel.org>
>> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
>> Cc: Mike Leach <mike.leach@linaro.org>
>> Cc: Leo Yan <leo.yan@linaro.org>
>> Cc: Sudeep Holla <sudeep.holla@arm.com>
>> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
>> Cc: linux-acpi@vger.kernel.org
>> Cc: coresight@lists.linaro.org
>> Cc: linux-arm-kernel@lists.infradead.org
>> Cc: linux-kernel@vger.kernel.org
>> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> (for ACPI specific 
>> changes)
>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> 
> We would like to queue this via coresight tree. The acpi_amba bits have
> been reviewed by Sudeep. Please could you give us an Ack, if you are
> happy with the proposal ?
> 

Kind regards
Suzuki

> Kind regards
> Suzuki
> 
> 
>> ---
>>   drivers/acpi/acpi_amba.c                           |  1 -
>>   drivers/hwtracing/coresight/coresight-etm4x-core.c | 10 ++++++++++
>>   2 files changed, 10 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/acpi/acpi_amba.c b/drivers/acpi/acpi_amba.c
>> index f5b443ab01c2..099966cbac5a 100644
>> --- a/drivers/acpi/acpi_amba.c
>> +++ b/drivers/acpi/acpi_amba.c
>> @@ -22,7 +22,6 @@
>>   static const struct acpi_device_id amba_id_list[] = {
>>       {"ARMH0061", 0}, /* PL061 GPIO Device */
>>       {"ARMH0330", 0}, /* ARM DMA Controller DMA-330 */
>> -    {"ARMHC500", 0}, /* ARM CoreSight ETM4x */
>>       {"ARMHC501", 0}, /* ARM CoreSight ETR */
>>       {"ARMHC502", 0}, /* ARM CoreSight STM */
>>       {"ARMHC503", 0}, /* ARM CoreSight Debug */
>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c 
>> b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> index 43f583987250..703b6fcbb6a5 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> @@ -3,6 +3,7 @@
>>    * Copyright (c) 2014, The Linux Foundation. All rights reserved.
>>    */
>> +#include <linux/acpi.h>
>>   #include <linux/bitops.h>
>>   #include <linux/kernel.h>
>>   #include <linux/moduleparam.h>
>> @@ -2347,12 +2348,21 @@ 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 */
>> +    {}
>> +};
>> +MODULE_DEVICE_TABLE(acpi, etm4x_acpi_ids);
>> +#endif
>> +
>>   static struct platform_driver etm4_platform_driver = {
>>       .probe        = etm4_probe_platform_dev,
>>       .remove        = etm4_remove_platform_dev,
>>       .driver            = {
>>           .name            = "coresight-etm4x",
>>           .of_match_table        = etm4_sysreg_match,
>> +        .acpi_match_table    = ACPI_PTR(etm4x_acpi_ids),
>>           .suppress_bind_attrs    = true,
>>           .pm            = &etm4_dev_pm_ops,
>>       },
> 

Re: [PATCH V6 6/6] coresight: etm4x: Add ACPI support in platform driver

[Tanmay Jagdale]

Hi Rafael, Len, Suzuki,

> Rafael, Len
> 
> Ping (packets 6, lost 100%).
>

We have a Marvell SoC based on ARMv9 architecture with Coresight ETE.

Without this patchset, we get following error on our platform:
[    0.042733] acpi ARMHC500:00: amba_handler_attach(): amba_device_add() failed (-16)

This patchset fixes the issue and helps in successfully probing
the Coresight ETE device when booted with ACPI tables.

Tested-by: Tanmay Jagdale <tanmay@marvell.com>

With Regards,
Tanmay

> 
> On 10/07/2023 17:40, Suzuki K Poulose wrote:
> > Rafael, Len
> >
> > On 10/07/2023 07:25, Anshuman Khandual wrote:
> >> From: Suzuki K Poulose <suzuki.poulose@arm.com>
> >>
> >> Drop ETM4X ACPI ID from the AMBA ACPI device list, and instead just
> >> move it
> >> inside the new ACPI devices list detected and used via platform driver.
> >>
> >> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> >> Cc: Len Brown <lenb@kernel.org>
> >> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> >> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
> >> Cc: Mike Leach <mike.leach@linaro.org>
> >> Cc: Leo Yan <leo.yan@linaro.org>
> >> Cc: Sudeep Holla <sudeep.holla@arm.com>
> >> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
> >> Cc: linux-acpi@vger.kernel.org
> >> Cc: coresight@lists.linaro.org
> >> Cc: linux-arm-kernel@lists.infradead.org
> >> Cc: linux-kernel@vger.kernel.org
> >> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> (for ACPI specific
> >> changes)
> >> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> >> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> >
> > We would like to queue this via coresight tree. The acpi_amba bits have
> > been reviewed by Sudeep. Please could you give us an Ack, if you are
> > happy with the proposal ?
> >
> 
> Kind regards
> Suzuki
> 
> > Kind regards
> > Suzuki
> >
> >
> >> ---
> >>   drivers/acpi/acpi_amba.c                           |  1 -
> >>   drivers/hwtracing/coresight/coresight-etm4x-core.c | 10 ++++++++++
> >>   2 files changed, 10 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/acpi/acpi_amba.c b/drivers/acpi/acpi_amba.c
> >> index f5b443ab01c2..099966cbac5a 100644
> >> --- a/drivers/acpi/acpi_amba.c
> >> +++ b/drivers/acpi/acpi_amba.c
> >> @@ -22,7 +22,6 @@
> >>   static const struct acpi_device_id amba_id_list[] = {
> >>       {"ARMH0061", 0}, /* PL061 GPIO Device */
> >>       {"ARMH0330", 0}, /* ARM DMA Controller DMA-330 */
> >> -    {"ARMHC500", 0}, /* ARM CoreSight ETM4x */
> >>       {"ARMHC501", 0}, /* ARM CoreSight ETR */
> >>       {"ARMHC502", 0}, /* ARM CoreSight STM */
> >>       {"ARMHC503", 0}, /* ARM CoreSight Debug */
> >> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> >> b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> >> index 43f583987250..703b6fcbb6a5 100644
> >> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> >> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> >> @@ -3,6 +3,7 @@
> >>    * Copyright (c) 2014, The Linux Foundation. All rights reserved.
> >>    */
> >> +#include <linux/acpi.h>
> >>   #include <linux/bitops.h>
> >>   #include <linux/kernel.h>
> >>   #include <linux/moduleparam.h>
> >> @@ -2347,12 +2348,21 @@ 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 */
> >> +    {}
> >> +};
> >> +MODULE_DEVICE_TABLE(acpi, etm4x_acpi_ids);
> >> +#endif
> >> +
> >>   static struct platform_driver etm4_platform_driver = {
> >>       .probe        = etm4_probe_platform_dev,
> >>       .remove        = etm4_remove_platform_dev,
> >>       .driver            = {
> >>           .name            = "coresight-etm4x",
> >>           .of_match_table        = etm4_sysreg_match,
> >> +        .acpi_match_table    = ACPI_PTR(etm4x_acpi_ids),
> >>           .suppress_bind_attrs    = true,
> >>           .pm            = &etm4_dev_pm_ops,
> >>       },
> >
> 
> _______________________________________________
> CoreSight mailing list -- coresight@lists.linaro.org
> To unsubscribe send an email to coresight-leave@lists.linaro.org

acpi: Remove ETM from AMBA scan list (was Re: [PATCH V6 6/6] coresight: etm4x: Add ACPI support in platform driver)

[Suzuki K Poulose]

Hi Rafael/Len

On 19/07/2023 11:11, Suzuki K Poulose wrote:
> Rafael, Len
> 
> Ping (packets 6, lost 100%).
> 
> 
> On 10/07/2023 17:40, Suzuki K Poulose wrote:
>> Rafael, Len
>>
>> On 10/07/2023 07:25, Anshuman Khandual wrote:
>>> From: Suzuki K Poulose <suzuki.poulose@arm.com>
>>>
>>> Drop ETM4X ACPI ID from the AMBA ACPI device list, and instead just 
>>> move it
>>> inside the new ACPI devices list detected and used via platform driver.
>>>
>>> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
>>> Cc: Len Brown <lenb@kernel.org>
>>> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
>>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
>>> Cc: Mike Leach <mike.leach@linaro.org>
>>> Cc: Leo Yan <leo.yan@linaro.org>
>>> Cc: Sudeep Holla <sudeep.holla@arm.com>
>>> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
>>> Cc: linux-acpi@vger.kernel.org
>>> Cc: coresight@lists.linaro.org
>>> Cc: linux-arm-kernel@lists.infradead.org
>>> Cc: linux-kernel@vger.kernel.org
>>> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> (for ACPI specific 
>>> changes)
>>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
>>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>>
>> We would like to queue this via coresight tree. The acpi_amba bits have
>> been reviewed by Sudeep. Please could you give us an Ack, if you are
>> happy with the proposal ?
>>

Please could one of you respond to this patch ? We are blocked on your 
Ack for queuing this. There are machines out there, which rely on this
patch to use Arm self-hosted tracing based on CoreSight.

Kind regards
Suzuki

> 
> Kind regards
> Suzuki
> 
>> Kind regards
>> Suzuki
>>
>>
>>> ---
>>>   drivers/acpi/acpi_amba.c                           |  1 -
>>>   drivers/hwtracing/coresight/coresight-etm4x-core.c | 10 ++++++++++
>>>   2 files changed, 10 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/acpi/acpi_amba.c b/drivers/acpi/acpi_amba.c
>>> index f5b443ab01c2..099966cbac5a 100644
>>> --- a/drivers/acpi/acpi_amba.c
>>> +++ b/drivers/acpi/acpi_amba.c
>>> @@ -22,7 +22,6 @@
>>>   static const struct acpi_device_id amba_id_list[] = {
>>>       {"ARMH0061", 0}, /* PL061 GPIO Device */
>>>       {"ARMH0330", 0}, /* ARM DMA Controller DMA-330 */
>>> -    {"ARMHC500", 0}, /* ARM CoreSight ETM4x */
>>>       {"ARMHC501", 0}, /* ARM CoreSight ETR */
>>>       {"ARMHC502", 0}, /* ARM CoreSight STM */
>>>       {"ARMHC503", 0}, /* ARM CoreSight Debug */
>>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c 
>>> b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>>> index 43f583987250..703b6fcbb6a5 100644
>>> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
>>> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>>> @@ -3,6 +3,7 @@
>>>    * Copyright (c) 2014, The Linux Foundation. All rights reserved.
>>>    */
>>> +#include <linux/acpi.h>
>>>   #include <linux/bitops.h>
>>>   #include <linux/kernel.h>
>>>   #include <linux/moduleparam.h>
>>> @@ -2347,12 +2348,21 @@ 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 */
>>> +    {}
>>> +};
>>> +MODULE_DEVICE_TABLE(acpi, etm4x_acpi_ids);
>>> +#endif
>>> +
>>>   static struct platform_driver etm4_platform_driver = {
>>>       .probe        = etm4_probe_platform_dev,
>>>       .remove        = etm4_remove_platform_dev,
>>>       .driver            = {
>>>           .name            = "coresight-etm4x",
>>>           .of_match_table        = etm4_sysreg_match,
>>> +        .acpi_match_table    = ACPI_PTR(etm4x_acpi_ids),
>>>           .suppress_bind_attrs    = true,
>>>           .pm            = &etm4_dev_pm_ops,
>>>       },
>>
> 

Re: acpi: Remove ETM from AMBA scan list (was Re: [PATCH V6 6/6] coresight: etm4x: Add ACPI support in platform driver)

[Steve Clevenger OS]

Hi Rafael, Len,

On 7/24/2023 9:25 AM, Suzuki K Poulose wrote:
> Hi Rafael/Len
> 
> On 19/07/2023 11:11, Suzuki K Poulose wrote:
>> Rafael, Len
>>
>> Ping (packets 6, lost 100%).
>>
>>
>> On 10/07/2023 17:40, Suzuki K Poulose wrote:
>>> Rafael, Len
>>>
>>> On 10/07/2023 07:25, Anshuman Khandual wrote:
>>>> From: Suzuki K Poulose <suzuki.poulose@arm.com>
>>>>
>>>> Drop ETM4X ACPI ID from the AMBA ACPI device list, and instead just
>>>> move it
>>>> inside the new ACPI devices list detected and used via platform driver.
>>>>
>>>> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
>>>> Cc: Len Brown <lenb@kernel.org>
>>>> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
>>>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
>>>> Cc: Mike Leach <mike.leach@linaro.org>
>>>> Cc: Leo Yan <leo.yan@linaro.org>
>>>> Cc: Sudeep Holla <sudeep.holla@arm.com>
>>>> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
>>>> Cc: linux-acpi@vger.kernel.org
>>>> Cc: coresight@lists.linaro.org
>>>> Cc: linux-arm-kernel@lists.infradead.org
>>>> Cc: linux-kernel@vger.kernel.org
>>>> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> (for ACPI specific
>>>> changes)
>>>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
>>>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>>>
>>> We would like to queue this via coresight tree. The acpi_amba bits have
>>> been reviewed by Sudeep. Please could you give us an Ack, if you are
>>> happy with the proposal ?
>>>
> 
> Please could one of you respond to this patch ? We are blocked on your
> Ack for queuing this. There are machines out there, which rely on this
> patch to use Arm self-hosted tracing based on CoreSight.
> 
> Kind regards
> Suzuki

Ampere Computing AmpereOne machines rely on this patch series to enable
System Register Access to the ETMv4. Ampere removed the ETM MMIO
descriptions from our CoreSight ACPI to use this.

Suzuki's e-mail requests for review/Ack of this patch thread date back
to May 30.

Thanks in advance,
Steve C.

> 
>>
>> Kind regards
>> Suzuki
>>
>>> Kind regards
>>> Suzuki
>>>
>>>
>>>> ---
>>>>   drivers/acpi/acpi_amba.c                           |  1 -
>>>>   drivers/hwtracing/coresight/coresight-etm4x-core.c | 10 ++++++++++
>>>>   2 files changed, 10 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/acpi/acpi_amba.c b/drivers/acpi/acpi_amba.c
>>>> index f5b443ab01c2..099966cbac5a 100644
>>>> --- a/drivers/acpi/acpi_amba.c
>>>> +++ b/drivers/acpi/acpi_amba.c
>>>> @@ -22,7 +22,6 @@
>>>>   static const struct acpi_device_id amba_id_list[] = {
>>>>       {"ARMH0061", 0}, /* PL061 GPIO Device */
>>>>       {"ARMH0330", 0}, /* ARM DMA Controller DMA-330 */
>>>> -    {"ARMHC500", 0}, /* ARM CoreSight ETM4x */
>>>>       {"ARMHC501", 0}, /* ARM CoreSight ETR */
>>>>       {"ARMHC502", 0}, /* ARM CoreSight STM */
>>>>       {"ARMHC503", 0}, /* ARM CoreSight Debug */
>>>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c
>>>> b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>>>> index 43f583987250..703b6fcbb6a5 100644
>>>> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
>>>> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>>>> @@ -3,6 +3,7 @@
>>>>    * Copyright (c) 2014, The Linux Foundation. All rights reserved.
>>>>    */
>>>> +#include <linux/acpi.h>
>>>>   #include <linux/bitops.h>
>>>>   #include <linux/kernel.h>
>>>>   #include <linux/moduleparam.h>
>>>> @@ -2347,12 +2348,21 @@ 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 */
>>>> +    {}
>>>> +};
>>>> +MODULE_DEVICE_TABLE(acpi, etm4x_acpi_ids);
>>>> +#endif
>>>> +
>>>>   static struct platform_driver etm4_platform_driver = {
>>>>       .probe        = etm4_probe_platform_dev,
>>>>       .remove        = etm4_remove_platform_dev,
>>>>       .driver            = {
>>>>           .name            = "coresight-etm4x",
>>>>           .of_match_table        = etm4_sysreg_match,
>>>> +        .acpi_match_table    = ACPI_PTR(etm4x_acpi_ids),
>>>>           .suppress_bind_attrs    = true,
>>>>           .pm            = &etm4_dev_pm_ops,
>>>>       },
>>>
>>
> 

Re: acpi: Remove ETM from AMBA scan list (was Re: [PATCH V6 6/6] coresight: etm4x: Add ACPI support in platform driver)

[Rafael J. Wysocki]

On Tue, Jul 25, 2023 at 10:18 PM Steve Clevenger OS
<scclevenger@os.amperecomputing.com> wrote:
>
>
> Hi Rafael, Len,
>
> On 7/24/2023 9:25 AM, Suzuki K Poulose wrote:
> > Hi Rafael/Len
> >
> > On 19/07/2023 11:11, Suzuki K Poulose wrote:
> >> Rafael, Len
> >>
> >> Ping (packets 6, lost 100%).
> >>
> >>
> >> On 10/07/2023 17:40, Suzuki K Poulose wrote:
> >>> Rafael, Len
> >>>
> >>> On 10/07/2023 07:25, Anshuman Khandual wrote:
> >>>> From: Suzuki K Poulose <suzuki.poulose@arm.com>
> >>>>
> >>>> Drop ETM4X ACPI ID from the AMBA ACPI device list, and instead just
> >>>> move it
> >>>> inside the new ACPI devices list detected and used via platform driver.
> >>>>
> >>>> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> >>>> Cc: Len Brown <lenb@kernel.org>
> >>>> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> >>>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
> >>>> Cc: Mike Leach <mike.leach@linaro.org>
> >>>> Cc: Leo Yan <leo.yan@linaro.org>
> >>>> Cc: Sudeep Holla <sudeep.holla@arm.com>
> >>>> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
> >>>> Cc: linux-acpi@vger.kernel.org
> >>>> Cc: coresight@lists.linaro.org
> >>>> Cc: linux-arm-kernel@lists.infradead.org
> >>>> Cc: linux-kernel@vger.kernel.org
> >>>> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> (for ACPI specific
> >>>> changes)
> >>>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> >>>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> >>>
> >>> We would like to queue this via coresight tree. The acpi_amba bits have
> >>> been reviewed by Sudeep. Please could you give us an Ack, if you are
> >>> happy with the proposal ?
> >>>
> >
> > Please could one of you respond to this patch ? We are blocked on your
> > Ack for queuing this. There are machines out there, which rely on this
> > patch to use Arm self-hosted tracing based on CoreSight.
> >
> > Kind regards
> > Suzuki
>
> Ampere Computing AmpereOne machines rely on this patch series to enable
> System Register Access to the ETMv4. Ampere removed the ETM MMIO
> descriptions from our CoreSight ACPI to use this.
>
> Suzuki's e-mail requests for review/Ack of this patch thread date back
> to May 30.

I've just talked to Suzuki about this:

https://lore.kernel.org/linux-acpi/20230726140515.368981-1-suzuki.poulose@arm.com

This patch has received a Reviewed-by from Sudeep which for all
purposes should be sufficient for any ARM-related ACPI material that
doesn't affect any other architectures.  An ACK from me (or Len for
that matter) would not make any real difference from the technical
perspective.

I would appreciate assigning an official ARM maintainer to acpi_amba.c
so as to avoid such unnecessary delays in the future.

Re: acpi: Remove ETM from AMBA scan list (was Re: [PATCH V6 6/6] coresight: etm4x: Add ACPI support in platform driver)

[Sudeep Holla]

On Wed, Jul 26, 2023 at 04:33:26PM +0200, Rafael J. Wysocki wrote:
> On Tue, Jul 25, 2023 at 10:18 PM Steve Clevenger OS
> <scclevenger@os.amperecomputing.com> wrote:
> >
> >
> > Hi Rafael, Len,
> >
> > On 7/24/2023 9:25 AM, Suzuki K Poulose wrote:
> > > Hi Rafael/Len
> > >
> > > On 19/07/2023 11:11, Suzuki K Poulose wrote:
> > >> Rafael, Len
> > >>
> > >> Ping (packets 6, lost 100%).
> > >>
> > >>
> > >> On 10/07/2023 17:40, Suzuki K Poulose wrote:
> > >>> Rafael, Len
> > >>>
> > >>> On 10/07/2023 07:25, Anshuman Khandual wrote:
> > >>>> From: Suzuki K Poulose <suzuki.poulose@arm.com>
> > >>>>
> > >>>> Drop ETM4X ACPI ID from the AMBA ACPI device list, and instead just
> > >>>> move it
> > >>>> inside the new ACPI devices list detected and used via platform driver.
> > >>>>
> > >>>> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
> > >>>> Cc: Len Brown <lenb@kernel.org>
> > >>>> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> > >>>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
> > >>>> Cc: Mike Leach <mike.leach@linaro.org>
> > >>>> Cc: Leo Yan <leo.yan@linaro.org>
> > >>>> Cc: Sudeep Holla <sudeep.holla@arm.com>
> > >>>> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
> > >>>> Cc: linux-acpi@vger.kernel.org
> > >>>> Cc: coresight@lists.linaro.org
> > >>>> Cc: linux-arm-kernel@lists.infradead.org
> > >>>> Cc: linux-kernel@vger.kernel.org
> > >>>> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> (for ACPI specific
> > >>>> changes)
> > >>>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> > >>>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
> > >>>
> > >>> We would like to queue this via coresight tree. The acpi_amba bits have
> > >>> been reviewed by Sudeep. Please could you give us an Ack, if you are
> > >>> happy with the proposal ?
> > >>>
> > >
> > > Please could one of you respond to this patch ? We are blocked on your
> > > Ack for queuing this. There are machines out there, which rely on this
> > > patch to use Arm self-hosted tracing based on CoreSight.
> > >
> > > Kind regards
> > > Suzuki
> >
> > Ampere Computing AmpereOne machines rely on this patch series to enable
> > System Register Access to the ETMv4. Ampere removed the ETM MMIO
> > descriptions from our CoreSight ACPI to use this.
> >
> > Suzuki's e-mail requests for review/Ack of this patch thread date back
> > to May 30.
> 
> I've just talked to Suzuki about this:
> 
> https://lore.kernel.org/linux-acpi/20230726140515.368981-1-suzuki.poulose@arm.com
> 
> This patch has received a Reviewed-by from Sudeep which for all
> purposes should be sufficient for any ARM-related ACPI material that
> doesn't affect any other architectures.  An ACK from me (or Len for
> that matter) would not make any real difference from the technical
> perspective.
> 
> I would appreciate assigning an official ARM maintainer to acpi_amba.c
> so as to avoid such unnecessary delays in the future.

Ah I just crossed and replied on other thread. I will soon send an update
to add this file under Arm ACPI for the maintenance.

-- 
Regards,
Sudeep

Re: acpi: Remove ETM from AMBA scan list (was Re: [PATCH V6 6/6] coresight: etm4x: Add ACPI support in platform driver)

[Steve Clevenger OS]

Hi Sudeep,

On 7/26/2023 8:03 AM, Sudeep Holla wrote:
> On Wed, Jul 26, 2023 at 04:33:26PM +0200, Rafael J. Wysocki wrote:
>> On Tue, Jul 25, 2023 at 10:18 PM Steve Clevenger OS
>> <scclevenger@os.amperecomputing.com> wrote:
>>>
>>>
>>> Hi Rafael, Len,
>>>
>>> On 7/24/2023 9:25 AM, Suzuki K Poulose wrote:
>>>> Hi Rafael/Len
>>>>
>>>> On 19/07/2023 11:11, Suzuki K Poulose wrote:
>>>>> Rafael, Len
>>>>>
>>>>> Ping (packets 6, lost 100%).
>>>>>
>>>>>
>>>>> On 10/07/2023 17:40, Suzuki K Poulose wrote:
>>>>>> Rafael, Len
>>>>>>
>>>>>> On 10/07/2023 07:25, Anshuman Khandual wrote:
>>>>>>> From: Suzuki K Poulose <suzuki.poulose@arm.com>
>>>>>>>
>>>>>>> Drop ETM4X ACPI ID from the AMBA ACPI device list, and instead just
>>>>>>> move it
>>>>>>> inside the new ACPI devices list detected and used via platform driver.
>>>>>>>
>>>>>>> Cc: "Rafael J. Wysocki" <rafael@kernel.org>
>>>>>>> Cc: Len Brown <lenb@kernel.org>
>>>>>>> Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
>>>>>>> Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
>>>>>>> Cc: Mike Leach <mike.leach@linaro.org>
>>>>>>> Cc: Leo Yan <leo.yan@linaro.org>
>>>>>>> Cc: Sudeep Holla <sudeep.holla@arm.com>
>>>>>>> Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
>>>>>>> Cc: linux-acpi@vger.kernel.org
>>>>>>> Cc: coresight@lists.linaro.org
>>>>>>> Cc: linux-arm-kernel@lists.infradead.org
>>>>>>> Cc: linux-kernel@vger.kernel.org
>>>>>>> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> (for ACPI specific
>>>>>>> changes)
>>>>>>> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
>>>>>>> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
>>>>>>
>>>>>> We would like to queue this via coresight tree. The acpi_amba bits have
>>>>>> been reviewed by Sudeep. Please could you give us an Ack, if you are
>>>>>> happy with the proposal ?
>>>>>>
>>>>
>>>> Please could one of you respond to this patch ? We are blocked on your
>>>> Ack for queuing this. There are machines out there, which rely on this
>>>> patch to use Arm self-hosted tracing based on CoreSight.
>>>>
>>>> Kind regards
>>>> Suzuki
>>>
>>> Ampere Computing AmpereOne machines rely on this patch series to enable
>>> System Register Access to the ETMv4. Ampere removed the ETM MMIO
>>> descriptions from our CoreSight ACPI to use this.
>>>
>>> Suzuki's e-mail requests for review/Ack of this patch thread date back
>>> to May 30.
>>
>> I've just talked to Suzuki about this:
>>
>> https://lore.kernel.org/linux-acpi/20230726140515.368981-1-suzuki.poulose@arm.com
>>
>> This patch has received a Reviewed-by from Sudeep which for all
>> purposes should be sufficient for any ARM-related ACPI material that
>> doesn't affect any other architectures.  An ACK from me (or Len for
>> that matter) would not make any real difference from the technical
>> perspective.
>>
>> I would appreciate assigning an official ARM maintainer to acpi_amba.c
>> so as to avoid such unnecessary delays in the future.
> 
> Ah I just crossed and replied on other thread. I will soon send an update
> to add this file under Arm ACPI for the maintenance.
> 

Thank you.

Steve C.

Re: [PATCH V6 0/6] coresight: etm4x: Migrate ACPI AMBA devices to platform driver

[Suzuki K Poulose]

On 10/07/2023 07:24, Anshuman Khandual wrote:
> CoreSight ETM4x devices could be accessed either via MMIO (handled via
> amba_driver) or CPU system instructions (handled via platform driver). But
> this has the following issues :
> 
>    - Each new CPU comes up with its own PID and thus we need to keep on
>      adding the "known" PIDs to get it working with AMBA driver. While
>      the ETM4 architecture (and CoreSight architecture) defines way to
>      identify a device as ETM4. Thus older kernels  won't be able to
>      "discover" a newer CPU, unless we add the PIDs.
> 
>    - With ACPI, the ETM4x devices have the same HID to identify the device
>      irrespective of the mode of access. This creates a problem where two
>      different drivers (both AMBA based driver and platform driver) would
>      hook into the "HID" and could conflict. e.g., if AMBA driver gets
>      hold of a non-MMIO device, the probe fails. If we have single driver
>      hooked into the given "HID", we could handle them seamlessly,
>      irrespective of the mode of access.
> 
>    - CoreSight is heavily dependent on the runtime power management. With
>      ACPI, amba_driver doesn't get us anywhere with handling the power
>      and thus one need to always turn the power ON to use them. Moving to
>      platform driver gives us the power management for free.
> 
> Due to all of the above, we are moving ACPI MMIO based etm4x devices to be
> supported via tha platform driver. The series makes the existing platform
> driver generic to handle both type of the access modes. Although existing
> AMBA driver would still continue to support DT based etm4x MMIO devices.
> Although some problems still remain, such as manually adding PIDs for all
> new AMBA DT based devices.
> 
> The series applies on 6.5-rc1.
> 
> Changes in V6:
> 
> - Rebased on 6.5-rc1
> 

I have queued this version for v6.6, should appear on coresight/next soon.

Suzuki

Re: [PATCH V6 0/6] coresight: etm4x: Migrate ACPI AMBA devices to platform driver

[Steve Clevenger OS]

Hi Suzuki,

On 7/26/2023 9:59 AM, Suzuki K Poulose wrote:
> On 10/07/2023 07:24, Anshuman Khandual wrote:
>> CoreSight ETM4x devices could be accessed either via MMIO (handled via
>> amba_driver) or CPU system instructions (handled via platform driver).
>> But
>> this has the following issues :
>>
>>    - Each new CPU comes up with its own PID and thus we need to keep on
>>      adding the "known" PIDs to get it working with AMBA driver. While
>>      the ETM4 architecture (and CoreSight architecture) defines way to
>>      identify a device as ETM4. Thus older kernels  won't be able to
>>      "discover" a newer CPU, unless we add the PIDs.
>>
>>    - With ACPI, the ETM4x devices have the same HID to identify the
>> device
>>      irrespective of the mode of access. This creates a problem where two
>>      different drivers (both AMBA based driver and platform driver) would
>>      hook into the "HID" and could conflict. e.g., if AMBA driver gets
>>      hold of a non-MMIO device, the probe fails. If we have single driver
>>      hooked into the given "HID", we could handle them seamlessly,
>>      irrespective of the mode of access.
>>
>>    - CoreSight is heavily dependent on the runtime power management. With
>>      ACPI, amba_driver doesn't get us anywhere with handling the power
>>      and thus one need to always turn the power ON to use them. Moving to
>>      platform driver gives us the power management for free.
>>
>> Due to all of the above, we are moving ACPI MMIO based etm4x devices
>> to be
>> supported via tha platform driver. The series makes the existing platform
>> driver generic to handle both type of the access modes. Although existing
>> AMBA driver would still continue to support DT based etm4x MMIO devices.
>> Although some problems still remain, such as manually adding PIDs for all
>> new AMBA DT based devices.
>>
>> The series applies on 6.5-rc1.
>>
>> Changes in V6:
>>
>> - Rebased on 6.5-rc1
>>
> 
> I have queued this version for v6.6, should appear on coresight/next soon.
> 
> Suzuki

Is there anyway to queue this for 6.5? Or has that ship sailed?

Thanks,

Steve C.

Re: [PATCH V6 0/6] coresight: etm4x: Migrate ACPI AMBA devices to platform driver

[Suzuki K Poulose]

On 26/07/2023 18:03, Steve Clevenger OS wrote:
> 
> Hi Suzuki,
> 
> On 7/26/2023 9:59 AM, Suzuki K Poulose wrote:
>> On 10/07/2023 07:24, Anshuman Khandual wrote:
>>> CoreSight ETM4x devices could be accessed either via MMIO (handled via
>>> amba_driver) or CPU system instructions (handled via platform driver).
>>> But
>>> this has the following issues :
>>>
>>>     - Each new CPU comes up with its own PID and thus we need to keep on
>>>       adding the "known" PIDs to get it working with AMBA driver. While
>>>       the ETM4 architecture (and CoreSight architecture) defines way to
>>>       identify a device as ETM4. Thus older kernels  won't be able to
>>>       "discover" a newer CPU, unless we add the PIDs.
>>>
>>>     - With ACPI, the ETM4x devices have the same HID to identify the
>>> device
>>>       irrespective of the mode of access. This creates a problem where two
>>>       different drivers (both AMBA based driver and platform driver) would
>>>       hook into the "HID" and could conflict. e.g., if AMBA driver gets
>>>       hold of a non-MMIO device, the probe fails. If we have single driver
>>>       hooked into the given "HID", we could handle them seamlessly,
>>>       irrespective of the mode of access.
>>>
>>>     - CoreSight is heavily dependent on the runtime power management. With
>>>       ACPI, amba_driver doesn't get us anywhere with handling the power
>>>       and thus one need to always turn the power ON to use them. Moving to
>>>       platform driver gives us the power management for free.
>>>
>>> Due to all of the above, we are moving ACPI MMIO based etm4x devices
>>> to be
>>> supported via tha platform driver. The series makes the existing platform
>>> driver generic to handle both type of the access modes. Although existing
>>> AMBA driver would still continue to support DT based etm4x MMIO devices.
>>> Although some problems still remain, such as manually adding PIDs for all
>>> new AMBA DT based devices.
>>>
>>> The series applies on 6.5-rc1.
>>>
>>> Changes in V6:
>>>
>>> - Rebased on 6.5-rc1
>>>
>>
>> I have queued this version for v6.6, should appear on coresight/next soon.
>>
>> Suzuki
> 
> Is there anyway to queue this for 6.5? Or has that ship sailed?

Only fixes are allowed for v6.5 at this time.

Suzuki

> 
> Thanks,
> 
> Steve C.