Merge tag 'coresight-next-v6.12' of...

Merge tag 'coresight-next-v6.12' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/coresight/linux into char-misc-next

Suzuki writes:

coresight: updates for Linux v6.12

CoreSight/hwtracing subsystem updates targeting Linux v6.12:
 - Miscellaneous fixes and cleanups
 - TraceID allocation per sink, allowing system with > 110 cores for
   perf tracing.
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

* tag 'coresight-next-v6.12' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/coresight/linux:
  coresight: Make trace ID map spinlock local to the map
  coresight: Emit sink ID in the HW_ID packets
  coresight: Remove pending trace ID release mechanism
  coresight: Use per-sink trace ID maps for Perf sessions
  coresight: Make CPU id map a property of a trace ID map
  coresight: Expose map arguments in trace ID API
  coresight: Move struct coresight_trace_id_map to common header
  coresight: Clarify comments around the PID of the sink owner
  coresight: Remove unused ETM Perf stubs
  coresight: tmc: sg: Do not leak sg_table
  Coresight: Set correct cs_mode for dummy source to fix disable issue
  Coresight: Set correct cs_mode for TPDM to fix disable issue
  coresight: cti: use device_* to iterate over device child nodes

drivers/hwtracing/coresight/coresight-core.c

@@ -487,23 +487,25 @@ struct coresight_device *coresight_get_sink(struct list_head *path)
 	return csdev;
 }
 
+u32 coresight_get_sink_id(struct coresight_device *csdev)
+{
+	if (!csdev->ea)
+		return 0;
+
+	/*
+	 * See function etm_perf_add_symlink_sink() to know where
+	 * this comes from.
+	 */
+	return (u32) (unsigned long) csdev->ea->var;
+}
+
 static int coresight_sink_by_id(struct device *dev, const void *data)
 {
 	struct coresight_device *csdev = to_coresight_device(dev);
-	unsigned long hash;
 
 	if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
-	     csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
-
-		if (!csdev->ea)
-			return 0;
-		/*
-		 * See function etm_perf_add_symlink_sink() to know where
-		 * this comes from.
-		 */
-		hash = (unsigned long)csdev->ea->var;
-
-		if ((u32)hash == *(u32 *)data)
+	    csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
+		if (coresight_get_sink_id(csdev) == *(u32 *)data)
 			return 1;
 	}
 
@@ -902,6 +904,7 @@ static void coresight_device_release(struct device *dev)
 	struct coresight_device *csdev = to_coresight_device(dev);
 
 	fwnode_handle_put(csdev->dev.fwnode);
+	free_percpu(csdev->perf_sink_id_map.cpu_map);
 	kfree(csdev);
 }
 
@@ -1159,6 +1162,16 @@ struct coresight_device *coresight_register(struct coresight_desc *desc)
 	csdev->dev.fwnode = fwnode_handle_get(dev_fwnode(desc->dev));
 	dev_set_name(&csdev->dev, "%s", desc->name);
 
+	if (csdev->type == CORESIGHT_DEV_TYPE_SINK ||
+	    csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) {
+		spin_lock_init(&csdev->perf_sink_id_map.lock);
+		csdev->perf_sink_id_map.cpu_map = alloc_percpu(atomic_t);
+		if (!csdev->perf_sink_id_map.cpu_map) {
+			kfree(csdev);
+			ret = -ENOMEM;
+			goto err_out;
+		}
+	}
 	/*
 	 * Make sure the device registration and the connection fixup
 	 * are synchronised, so that we don't see uninitialised devices

drivers/hwtracing/coresight/coresight-cti-platform.c

@@ -416,20 +416,16 @@ static int cti_plat_create_impdef_connections(struct device *dev,
 					      struct cti_drvdata *drvdata)
 {
 	int rc = 0;
-	struct fwnode_handle *fwnode = dev_fwnode(dev);
-	struct fwnode_handle *child = NULL;
 
-	if (IS_ERR_OR_NULL(fwnode))
+	if (IS_ERR_OR_NULL(dev_fwnode(dev)))
 		return -EINVAL;
 
-	fwnode_for_each_child_node(fwnode, child) {
+	device_for_each_child_node_scoped(dev, child) {
 		if (cti_plat_node_name_eq(child, CTI_DT_CONNS))
-			rc = cti_plat_create_connection(dev, drvdata,
-							child);
+			rc = cti_plat_create_connection(dev, drvdata, child);
 		if (rc != 0)
 			break;
 	}
-	fwnode_handle_put(child);
 
 	return rc;
 }

drivers/hwtracing/coresight/coresight-dummy.c

@@ -21,8 +21,12 @@ DEFINE_CORESIGHT_DEVLIST(source_devs, "dummy_source");
 DEFINE_CORESIGHT_DEVLIST(sink_devs, "dummy_sink");
 
 static int dummy_source_enable(struct coresight_device *csdev,
-			       struct perf_event *event, enum cs_mode mode)
+			       struct perf_event *event, enum cs_mode mode,
+			       __maybe_unused struct coresight_trace_id_map *id_map)
 {
+	if (!coresight_take_mode(csdev, mode))
+		return -EBUSY;
+
 	dev_dbg(csdev->dev.parent, "Dummy source enabled\n");
 
 	return 0;
@@ -31,6 +35,7 @@ static int dummy_source_enable(struct coresight_device *csdev,
 static void dummy_source_disable(struct coresight_device *csdev,
 				 struct perf_event *event)
 {
+	coresight_set_mode(csdev, CS_MODE_DISABLED);
 	dev_dbg(csdev->dev.parent, "Dummy source disabled\n");
 }
 

drivers/hwtracing/coresight/coresight-etm-perf.c

@@ -229,15 +229,24 @@ static void free_event_data(struct work_struct *work)
 		struct list_head **ppath;
 
 		ppath = etm_event_cpu_path_ptr(event_data, cpu);
-		if (!(IS_ERR_OR_NULL(*ppath)))
+		if (!(IS_ERR_OR_NULL(*ppath))) {
+			struct coresight_device *sink = coresight_get_sink(*ppath);
+
+			/*
+			 * Mark perf event as done for trace id allocator, but don't call
+			 * coresight_trace_id_put_cpu_id_map() on individual IDs. Perf sessions
+			 * never free trace IDs to ensure that the ID associated with a CPU
+			 * cannot change during their and other's concurrent sessions. Instead,
+			 * a refcount is used so that the last event to call
+			 * coresight_trace_id_perf_stop() frees all IDs.
+			 */
+			coresight_trace_id_perf_stop(&sink->perf_sink_id_map);
+
 			coresight_release_path(*ppath);
+		}
 		*ppath = NULL;
-		coresight_trace_id_put_cpu_id(cpu);
 	}
 
-	/* mark perf event as done for trace id allocator */
-	coresight_trace_id_perf_stop();
-
 	free_percpu(event_data->path);
 	kfree(event_data);
 }
@@ -325,9 +334,6 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
 		sink = user_sink = coresight_get_sink_by_id(id);
 	}
 
-	/* tell the trace ID allocator that a perf event is starting up */
-	coresight_trace_id_perf_start();
-
 	/* check if user wants a coresight configuration selected */
 	cfg_hash = (u32)((event->attr.config2 & GENMASK_ULL(63, 32)) >> 32);
 	if (cfg_hash) {
@@ -401,13 +407,14 @@ static void *etm_setup_aux(struct perf_event *event, void **pages,
 		}
 
 		/* ensure we can allocate a trace ID for this CPU */
-		trace_id = coresight_trace_id_get_cpu_id(cpu);
+		trace_id = coresight_trace_id_get_cpu_id_map(cpu, &sink->perf_sink_id_map);
 		if (!IS_VALID_CS_TRACE_ID(trace_id)) {
 			cpumask_clear_cpu(cpu, mask);
 			coresight_release_path(path);
 			continue;
 		}
 
+		coresight_trace_id_perf_start(&sink->perf_sink_id_map);
 		*etm_event_cpu_path_ptr(event_data, cpu) = path;
 	}
 
@@ -453,6 +460,7 @@ static void etm_event_start(struct perf_event *event, int flags)
 	struct coresight_device *sink, *csdev = per_cpu(csdev_src, cpu);
 	struct list_head *path;
 	u64 hw_id;
+	u8 trace_id;
 
 	if (!csdev)
 		goto fail;
@@ -495,7 +503,8 @@ static void etm_event_start(struct perf_event *event, int flags)
 		goto fail_end_stop;
 
 	/* Finally enable the tracer */
-	if (source_ops(csdev)->enable(csdev, event, CS_MODE_PERF))
+	if (source_ops(csdev)->enable(csdev, event, CS_MODE_PERF,
+				      &sink->perf_sink_id_map))
 		goto fail_disable_path;
 
 	/*
@@ -504,10 +513,16 @@ static void etm_event_start(struct perf_event *event, int flags)
 	 */
 	if (!cpumask_test_cpu(cpu, &event_data->aux_hwid_done)) {
 		cpumask_set_cpu(cpu, &event_data->aux_hwid_done);
-		hw_id = FIELD_PREP(CS_AUX_HW_ID_VERSION_MASK,
-				   CS_AUX_HW_ID_CURR_VERSION);
-		hw_id |= FIELD_PREP(CS_AUX_HW_ID_TRACE_ID_MASK,
-				    coresight_trace_id_read_cpu_id(cpu));
+
+		trace_id = coresight_trace_id_read_cpu_id_map(cpu, &sink->perf_sink_id_map);
+
+		hw_id = FIELD_PREP(CS_AUX_HW_ID_MAJOR_VERSION_MASK,
+				CS_AUX_HW_ID_MAJOR_VERSION);
+		hw_id |= FIELD_PREP(CS_AUX_HW_ID_MINOR_VERSION_MASK,
+				CS_AUX_HW_ID_MINOR_VERSION);
+		hw_id |= FIELD_PREP(CS_AUX_HW_ID_TRACE_ID_MASK, trace_id);
+		hw_id |= FIELD_PREP(CS_AUX_HW_ID_SINK_ID_MASK, coresight_get_sink_id(sink));
+
 		perf_report_aux_output_id(event, hw_id);
 	}
 

drivers/hwtracing/coresight/coresight-etm-perf.h

@@ -62,7 +62,6 @@ struct etm_event_data {
 	struct list_head * __percpu *path;
 };
 
-#if IS_ENABLED(CONFIG_CORESIGHT)
 int etm_perf_symlink(struct coresight_device *csdev, bool link);
 int etm_perf_add_symlink_sink(struct coresight_device *csdev);
 void etm_perf_del_symlink_sink(struct coresight_device *csdev);
@@ -77,23 +76,6 @@ static inline void *etm_perf_sink_config(struct perf_output_handle *handle)
 int etm_perf_add_symlink_cscfg(struct device *dev,
 			       struct cscfg_config_desc *config_desc);
 void etm_perf_del_symlink_cscfg(struct cscfg_config_desc *config_desc);
-#else
-static inline int etm_perf_symlink(struct coresight_device *csdev, bool link)
-{ return -EINVAL; }
-int etm_perf_add_symlink_sink(struct coresight_device *csdev)
-{ return -EINVAL; }
-void etm_perf_del_symlink_sink(struct coresight_device *csdev) {}
-static inline void *etm_perf_sink_config(struct perf_output_handle *handle)
-{
-	return NULL;
-}
-int etm_perf_add_symlink_cscfg(struct device *dev,
-			       struct cscfg_config_desc *config_desc)
-{ return -EINVAL; }
-void etm_perf_del_symlink_cscfg(struct cscfg_config_desc *config_desc) {}
-
-#endif /* CONFIG_CORESIGHT */
-
 int __init etm_perf_init(void);
 void etm_perf_exit(void);
 

drivers/hwtracing/coresight/coresight-etm3x-core.c

@@ -481,7 +481,8 @@ void etm_release_trace_id(struct etm_drvdata *drvdata)
 }
 
 static int etm_enable_perf(struct coresight_device *csdev,
-			   struct perf_event *event)
+			   struct perf_event *event,
+			   struct coresight_trace_id_map *id_map)
 {
 	struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 	int trace_id;
@@ -500,7 +501,7 @@ static int etm_enable_perf(struct coresight_device *csdev,
 	 * with perf locks - we know the ID cannot change until perf shuts down
 	 * the session
 	 */
-	trace_id = coresight_trace_id_read_cpu_id(drvdata->cpu);
+	trace_id = coresight_trace_id_read_cpu_id_map(drvdata->cpu, id_map);
 	if (!IS_VALID_CS_TRACE_ID(trace_id)) {
 		dev_err(&drvdata->csdev->dev, "Failed to set trace ID for %s on CPU%d\n",
 			dev_name(&drvdata->csdev->dev), drvdata->cpu);
@@ -553,7 +554,7 @@ static int etm_enable_sysfs(struct coresight_device *csdev)
 }
 
 static int etm_enable(struct coresight_device *csdev, struct perf_event *event,
-		      enum cs_mode mode)
+		      enum cs_mode mode, struct coresight_trace_id_map *id_map)
 {
 	int ret;
 	struct etm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -568,7 +569,7 @@ static int etm_enable(struct coresight_device *csdev, struct perf_event *event,
 		ret = etm_enable_sysfs(csdev);
 		break;
 	case CS_MODE_PERF:
-		ret = etm_enable_perf(csdev, event);
+		ret = etm_enable_perf(csdev, event, id_map);
 		break;
 	default:
 		ret = -EINVAL;

drivers/hwtracing/coresight/coresight-etm4x-core.c

@@ -752,7 +752,8 @@ static int etm4_parse_event_config(struct coresight_device *csdev,
 }
 
 static int etm4_enable_perf(struct coresight_device *csdev,
-			    struct perf_event *event)
+			    struct perf_event *event,
+			    struct coresight_trace_id_map *id_map)
 {
 	int ret = 0, trace_id;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
@@ -775,7 +776,7 @@ static int etm4_enable_perf(struct coresight_device *csdev,
 	 * with perf locks - we know the ID cannot change until perf shuts down
 	 * the session
 	 */
-	trace_id = coresight_trace_id_read_cpu_id(drvdata->cpu);
+	trace_id = coresight_trace_id_read_cpu_id_map(drvdata->cpu, id_map);
 	if (!IS_VALID_CS_TRACE_ID(trace_id)) {
 		dev_err(&drvdata->csdev->dev, "Failed to set trace ID for %s on CPU%d\n",
 			dev_name(&drvdata->csdev->dev), drvdata->cpu);
@@ -837,7 +838,7 @@ static int etm4_enable_sysfs(struct coresight_device *csdev)
 }
 
 static int etm4_enable(struct coresight_device *csdev, struct perf_event *event,
-		       enum cs_mode mode)
+		       enum cs_mode mode, struct coresight_trace_id_map *id_map)
 {
 	int ret;
 
@@ -851,7 +852,7 @@ static int etm4_enable(struct coresight_device *csdev, struct perf_event *event,
 		ret = etm4_enable_sysfs(csdev);
 		break;
 	case CS_MODE_PERF:
-		ret = etm4_enable_perf(csdev, event);
+		ret = etm4_enable_perf(csdev, event, id_map);
 		break;
 	default:
 		ret = -EINVAL;

drivers/hwtracing/coresight/coresight-priv.h

@@ -148,6 +148,7 @@ int coresight_make_links(struct coresight_device *orig,
 			 struct coresight_device *target);
 void coresight_remove_links(struct coresight_device *orig,
 			    struct coresight_connection *conn);
+u32 coresight_get_sink_id(struct coresight_device *csdev);
 
 #if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM3X)
 extern int etm_readl_cp14(u32 off, unsigned int *val);

drivers/hwtracing/coresight/coresight-stm.c

@@ -194,7 +194,8 @@ static void stm_enable_hw(struct stm_drvdata *drvdata)
 }
 
 static int stm_enable(struct coresight_device *csdev, struct perf_event *event,
-		      enum cs_mode mode)
+		      enum cs_mode mode,
+		      __maybe_unused struct coresight_trace_id_map *trace_id)
 {
 	struct stm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 

drivers/hwtracing/coresight/coresight-sysfs.c

@@ -9,6 +9,7 @@
 #include <linux/kernel.h>
 
 #include "coresight-priv.h"
+#include "coresight-trace-id.h"
 
 /*
  * Use IDR to map the hash of the source's device name
@@ -63,7 +64,7 @@ static int coresight_enable_source_sysfs(struct coresight_device *csdev,
 	 */
 	lockdep_assert_held(&coresight_mutex);
 	if (coresight_get_mode(csdev) != CS_MODE_SYSFS) {
-		ret = source_ops(csdev)->enable(csdev, data, mode);
+		ret = source_ops(csdev)->enable(csdev, data, mode, NULL);
 		if (ret)
 			return ret;
 	}

drivers/hwtracing/coresight/coresight-tmc-etr.c

@@ -36,7 +36,8 @@ struct etr_buf_hw {
  * etr_perf_buffer - Perf buffer used for ETR
  * @drvdata		- The ETR drvdaga this buffer has been allocated for.
  * @etr_buf		- Actual buffer used by the ETR
- * @pid			- The PID this etr_perf_buffer belongs to.
+ * @pid			- The PID of the session owner that etr_perf_buffer
+ *			  belongs to.
  * @snaphost		- Perf session mode
  * @nr_pages		- Number of pages in the ring buffer.
  * @pages		- Array of Pages in the ring buffer.
@@ -261,6 +262,7 @@ void tmc_free_sg_table(struct tmc_sg_table *sg_table)
 {
 	tmc_free_table_pages(sg_table);
 	tmc_free_data_pages(sg_table);
+	kfree(sg_table);
 }
 EXPORT_SYMBOL_GPL(tmc_free_sg_table);
 
@@ -342,7 +344,6 @@ struct tmc_sg_table *tmc_alloc_sg_table(struct device *dev,
 		rc = tmc_alloc_table_pages(sg_table);
 	if (rc) {
 		tmc_free_sg_table(sg_table);
-		kfree(sg_table);
 		return ERR_PTR(rc);
 	}
 
@@ -1662,7 +1663,7 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data)
 		goto unlock_out;
 	}
 
-	/* Get a handle on the pid of the process to monitor */
+	/* Get a handle on the pid of the session owner */
 	pid = etr_perf->pid;
 
 	/* Do not proceed if this device is associated with another session */

drivers/hwtracing/coresight/coresight-tmc.h

@@ -171,8 +171,9 @@ struct etr_buf {
  * @csdev:	component vitals needed by the framework.
  * @miscdev:	specifics to handle "/dev/xyz.tmc" entry.
  * @spinlock:	only one at a time pls.
- * @pid:	Process ID of the process being monitored by the session
- *		that is using this component.
+ * @pid:	Process ID of the process that owns the session that is using
+ *		this component. For example this would be the pid of the Perf
+ *		process.
  * @buf:	Snapshot of the trace data for ETF/ETB.
  * @etr_buf:	details of buffer used in TMC-ETR
  * @len:	size of the available trace for ETF/ETB.

drivers/hwtracing/coresight/coresight-tpdm.c

@@ -439,7 +439,8 @@ static void __tpdm_enable(struct tpdm_drvdata *drvdata)
 }
 
 static int tpdm_enable(struct coresight_device *csdev, struct perf_event *event,
-		       enum cs_mode mode)
+		       enum cs_mode mode,
+		       __maybe_unused struct coresight_trace_id_map *id_map)
 {
 	struct tpdm_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 
@@ -449,6 +450,11 @@ static int tpdm_enable(struct coresight_device *csdev, struct perf_event *event,
 		return -EBUSY;
 	}
 
+	if (!coresight_take_mode(csdev, mode)) {
+		spin_unlock(&drvdata->spinlock);
+		return -EBUSY;
+	}
+
 	__tpdm_enable(drvdata);
 	drvdata->enable = true;
 	spin_unlock(&drvdata->spinlock);
@@ -506,6 +512,7 @@ static void tpdm_disable(struct coresight_device *csdev,
 	}
 
 	__tpdm_disable(drvdata);
+	coresight_set_mode(csdev, CS_MODE_DISABLED);
 	drvdata->enable = false;
 	spin_unlock(&drvdata->spinlock);
 

drivers/hwtracing/coresight/coresight-trace-id.c

@@ -3,6 +3,7 @@
  * Copyright (c) 2022, Linaro Limited, All rights reserved.
  * Author: Mike Leach <mike.leach@linaro.org>
  */
+#include <linux/coresight.h>
 #include <linux/coresight-pmu.h>
 #include <linux/cpumask.h>
 #include <linux/kernel.h>
@@ -11,18 +12,12 @@
 
 #include "coresight-trace-id.h"
 
-/* Default trace ID map. Used on systems that don't require per sink mappings */
-static struct coresight_trace_id_map id_map_default;
-
-/* maintain a record of the mapping of IDs and pending releases per cpu */
-static DEFINE_PER_CPU(atomic_t, cpu_id) = ATOMIC_INIT(0);
-static cpumask_t cpu_id_release_pending;
-
-/* perf session active counter */
-static atomic_t perf_cs_etm_session_active = ATOMIC_INIT(0);
-
-/* lock to protect id_map and cpu data  */
-static DEFINE_SPINLOCK(id_map_lock);
+/* Default trace ID map. Used in sysfs mode and for system sources */
+static DEFINE_PER_CPU(atomic_t, id_map_default_cpu_ids) = ATOMIC_INIT(0);
+static struct coresight_trace_id_map id_map_default = {
+	.cpu_map = &id_map_default_cpu_ids,
+	.lock = __SPIN_LOCK_UNLOCKED(id_map_default.lock)
+};
 
 /* #define TRACE_ID_DEBUG 1 */
 #if defined(TRACE_ID_DEBUG) || defined(CONFIG_COMPILE_TEST)
@@ -32,7 +27,6 @@ static void coresight_trace_id_dump_table(struct coresight_trace_id_map *id_map,
 {
 	pr_debug("%s id_map::\n", func_name);
 	pr_debug("Used = %*pb\n", CORESIGHT_TRACE_IDS_MAX, id_map->used_ids);
-	pr_debug("Pend = %*pb\n", CORESIGHT_TRACE_IDS_MAX, id_map->pend_rel_ids);
 }
 #define DUMP_ID_MAP(map)   coresight_trace_id_dump_table(map, __func__)
 #define DUMP_ID_CPU(cpu, id) pr_debug("%s called;  cpu=%d, id=%d\n", __func__, cpu, id)
@@ -46,9 +40,9 @@ static void coresight_trace_id_dump_table(struct coresight_trace_id_map *id_map,
 #endif
 
 /* unlocked read of current trace ID value for given CPU */
-static int _coresight_trace_id_read_cpu_id(int cpu)
+static int _coresight_trace_id_read_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
 {
-	return atomic_read(&per_cpu(cpu_id, cpu));
+	return atomic_read(per_cpu_ptr(id_map->cpu_map, cpu));
 }
 
 /* look for next available odd ID, return 0 if none found */
@@ -119,49 +113,33 @@ static void coresight_trace_id_free(int id, struct coresight_trace_id_map *id_ma
 	clear_bit(id, id_map->used_ids);
 }
 
-static void coresight_trace_id_set_pend_rel(int id, struct coresight_trace_id_map *id_map)
-{
-	if (WARN(!IS_VALID_CS_TRACE_ID(id), "Invalid Trace ID %d\n", id))
-		return;
-	set_bit(id, id_map->pend_rel_ids);
-}
-
 /*
- * release all pending IDs for all current maps & clear CPU associations
- *
- * This currently operates on the default id map, but may be extended to
- * operate on all registered id maps if per sink id maps are used.
+ * Release all IDs and clear CPU associations.
  */
-static void coresight_trace_id_release_all_pending(void)
+static void coresight_trace_id_release_all(struct coresight_trace_id_map *id_map)
 {
-	struct coresight_trace_id_map *id_map = &id_map_default;
 	unsigned long flags;
-	int cpu, bit;
+	int cpu;
 
-	spin_lock_irqsave(&id_map_lock, flags);
-	for_each_set_bit(bit, id_map->pend_rel_ids, CORESIGHT_TRACE_ID_RES_TOP) {
-		clear_bit(bit, id_map->used_ids);
-		clear_bit(bit, id_map->pend_rel_ids);
-	}
-	for_each_cpu(cpu, &cpu_id_release_pending) {
-		atomic_set(&per_cpu(cpu_id, cpu), 0);
-		cpumask_clear_cpu(cpu, &cpu_id_release_pending);
-	}
-	spin_unlock_irqrestore(&id_map_lock, flags);
+	spin_lock_irqsave(&id_map->lock, flags);
+	bitmap_zero(id_map->used_ids, CORESIGHT_TRACE_IDS_MAX);
+	for_each_possible_cpu(cpu)
+		atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);
+	spin_unlock_irqrestore(&id_map->lock, flags);
 	DUMP_ID_MAP(id_map);
 }
 
-static int coresight_trace_id_map_get_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
+static int _coresight_trace_id_get_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
 {
 	unsigned long flags;
 	int id;
 
-	spin_lock_irqsave(&id_map_lock, flags);
+	spin_lock_irqsave(&id_map->lock, flags);
 
 	/* check for existing allocation for this CPU */
-	id = _coresight_trace_id_read_cpu_id(cpu);
+	id = _coresight_trace_id_read_cpu_id(cpu, id_map);
 	if (id)
-		goto get_cpu_id_clr_pend;
+		goto get_cpu_id_out_unlock;
 
 	/*
 	 * Find a new ID.
@@ -180,44 +158,32 @@ static int coresight_trace_id_map_get_cpu_id(int cpu, struct coresight_trace_id_
 		goto get_cpu_id_out_unlock;
 
 	/* allocate the new id to the cpu */
-	atomic_set(&per_cpu(cpu_id, cpu), id);
-
-get_cpu_id_clr_pend:
-	/* we are (re)using this ID - so ensure it is not marked for release */
-	cpumask_clear_cpu(cpu, &cpu_id_release_pending);
-	clear_bit(id, id_map->pend_rel_ids);
+	atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), id);
 
 get_cpu_id_out_unlock:
-	spin_unlock_irqrestore(&id_map_lock, flags);
+	spin_unlock_irqrestore(&id_map->lock, flags);
 
 	DUMP_ID_CPU(cpu, id);
 	DUMP_ID_MAP(id_map);
 	return id;
 }
 
-static void coresight_trace_id_map_put_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
+static void _coresight_trace_id_put_cpu_id(int cpu, struct coresight_trace_id_map *id_map)
 {
 	unsigned long flags;
 	int id;
 
 	/* check for existing allocation for this CPU */
-	id = _coresight_trace_id_read_cpu_id(cpu);
+	id = _coresight_trace_id_read_cpu_id(cpu, id_map);
 	if (!id)
 		return;
 
-	spin_lock_irqsave(&id_map_lock, flags);
+	spin_lock_irqsave(&id_map->lock, flags);
 
-	if (atomic_read(&perf_cs_etm_session_active)) {
-		/* set release at pending if perf still active */
-		coresight_trace_id_set_pend_rel(id, id_map);
-		cpumask_set_cpu(cpu, &cpu_id_release_pending);
-	} else {
-		/* otherwise clear id */
-		coresight_trace_id_free(id, id_map);
-		atomic_set(&per_cpu(cpu_id, cpu), 0);
-	}
+	coresight_trace_id_free(id, id_map);
+	atomic_set(per_cpu_ptr(id_map->cpu_map, cpu), 0);
 
-	spin_unlock_irqrestore(&id_map_lock, flags);
+	spin_unlock_irqrestore(&id_map->lock, flags);
 	DUMP_ID_CPU(cpu, id);
 	DUMP_ID_MAP(id_map);
 }
@@ -227,10 +193,10 @@ static int coresight_trace_id_map_get_system_id(struct coresight_trace_id_map *i
 	unsigned long flags;
 	int id;
 
-	spin_lock_irqsave(&id_map_lock, flags);
+	spin_lock_irqsave(&id_map->lock, flags);
 	/* prefer odd IDs for system components to avoid legacy CPU IDS */
 	id = coresight_trace_id_alloc_new_id(id_map, 0, true);
-	spin_unlock_irqrestore(&id_map_lock, flags);
+	spin_unlock_irqrestore(&id_map->lock, flags);
 
 	DUMP_ID(id);
 	DUMP_ID_MAP(id_map);
@@ -241,9 +207,9 @@ static void coresight_trace_id_map_put_system_id(struct coresight_trace_id_map *
 {
 	unsigned long flags;
 
-	spin_lock_irqsave(&id_map_lock, flags);
+	spin_lock_irqsave(&id_map->lock, flags);
 	coresight_trace_id_free(id, id_map);
-	spin_unlock_irqrestore(&id_map_lock, flags);
+	spin_unlock_irqrestore(&id_map->lock, flags);
 
 	DUMP_ID(id);
 	DUMP_ID_MAP(id_map);
@@ -253,22 +219,40 @@ static void coresight_trace_id_map_put_system_id(struct coresight_trace_id_map *
 
 int coresight_trace_id_get_cpu_id(int cpu)
 {
-	return coresight_trace_id_map_get_cpu_id(cpu, &id_map_default);
+	return _coresight_trace_id_get_cpu_id(cpu, &id_map_default);
 }
 EXPORT_SYMBOL_GPL(coresight_trace_id_get_cpu_id);
 
+int coresight_trace_id_get_cpu_id_map(int cpu, struct coresight_trace_id_map *id_map)
+{
+	return _coresight_trace_id_get_cpu_id(cpu, id_map);
+}
+EXPORT_SYMBOL_GPL(coresight_trace_id_get_cpu_id_map);
+
 void coresight_trace_id_put_cpu_id(int cpu)
 {
-	coresight_trace_id_map_put_cpu_id(cpu, &id_map_default);
+	_coresight_trace_id_put_cpu_id(cpu, &id_map_default);
 }
 EXPORT_SYMBOL_GPL(coresight_trace_id_put_cpu_id);
 
+void coresight_trace_id_put_cpu_id_map(int cpu, struct coresight_trace_id_map *id_map)
+{
+	_coresight_trace_id_put_cpu_id(cpu, id_map);
+}
+EXPORT_SYMBOL_GPL(coresight_trace_id_put_cpu_id_map);
+
 int coresight_trace_id_read_cpu_id(int cpu)
 {
-	return _coresight_trace_id_read_cpu_id(cpu);
+	return _coresight_trace_id_read_cpu_id(cpu, &id_map_default);
 }
 EXPORT_SYMBOL_GPL(coresight_trace_id_read_cpu_id);
 
+int coresight_trace_id_read_cpu_id_map(int cpu, struct coresight_trace_id_map *id_map)
+{
+	return _coresight_trace_id_read_cpu_id(cpu, id_map);
+}
+EXPORT_SYMBOL_GPL(coresight_trace_id_read_cpu_id_map);
+
 int coresight_trace_id_get_system_id(void)
 {
 	return coresight_trace_id_map_get_system_id(&id_map_default);
@@ -281,17 +265,17 @@ void coresight_trace_id_put_system_id(int id)
 }
 EXPORT_SYMBOL_GPL(coresight_trace_id_put_system_id);
 
-void coresight_trace_id_perf_start(void)
+void coresight_trace_id_perf_start(struct coresight_trace_id_map *id_map)
 {
-	atomic_inc(&perf_cs_etm_session_active);
-	PERF_SESSION(atomic_read(&perf_cs_etm_session_active));
+	atomic_inc(&id_map->perf_cs_etm_session_active);
+	PERF_SESSION(atomic_read(&id_map->perf_cs_etm_session_active));
 }
 EXPORT_SYMBOL_GPL(coresight_trace_id_perf_start);
 
-void coresight_trace_id_perf_stop(void)
+void coresight_trace_id_perf_stop(struct coresight_trace_id_map *id_map)
 {
-	if (!atomic_dec_return(&perf_cs_etm_session_active))
-		coresight_trace_id_release_all_pending();
-	PERF_SESSION(atomic_read(&perf_cs_etm_session_active));
+	if (!atomic_dec_return(&id_map->perf_cs_etm_session_active))
+		coresight_trace_id_release_all(id_map);
+	PERF_SESSION(atomic_read(&id_map->perf_cs_etm_session_active));
 }
 EXPORT_SYMBOL_GPL(coresight_trace_id_perf_stop);

drivers/hwtracing/coresight/coresight-trace-id.h

@@ -17,9 +17,10 @@
  * released when done.
  *
  * In order to ensure that a consistent cpu / ID matching is maintained
- * throughout a perf cs_etm event session - a session in progress flag will
- * be maintained, and released IDs not cleared until the perf session is
- * complete. This allows the same CPU to be re-allocated its prior ID.
+ * throughout a perf cs_etm event session - a session in progress flag will be
+ * maintained for each sink, and IDs are cleared when all the perf sessions
+ * complete. This allows the same CPU to be re-allocated its prior ID when
+ * events are scheduled in and out.
  *
  *
  * Trace ID maps will be created and initialised to prevent architecturally
@@ -32,10 +33,6 @@
 #include <linux/bitops.h>
 #include <linux/types.h>
 
-
-/* architecturally we have 128 IDs some of which are reserved */
-#define CORESIGHT_TRACE_IDS_MAX 128
-
 /* ID 0 is reserved */
 #define CORESIGHT_TRACE_ID_RES_0 0
 
@@ -46,23 +43,6 @@
 #define IS_VALID_CS_TRACE_ID(id)	\
 	((id > CORESIGHT_TRACE_ID_RES_0) && (id < CORESIGHT_TRACE_ID_RES_TOP))
 
-/**
- * Trace ID map.
- *
- * @used_ids:	Bitmap to register available (bit = 0) and in use (bit = 1) IDs.
- *		Initialised so that the reserved IDs are permanently marked as
- *		in use.
- * @pend_rel_ids: CPU IDs that have been released by the trace source but not
- *		  yet marked as available, to allow re-allocation to the same
- *		  CPU during a perf session.
- */
-struct coresight_trace_id_map {
-	DECLARE_BITMAP(used_ids, CORESIGHT_TRACE_IDS_MAX);
-	DECLARE_BITMAP(pend_rel_ids, CORESIGHT_TRACE_IDS_MAX);
-};
-
-/* Allocate and release IDs for a single default trace ID map */
-
 /**
  * Read and optionally allocate a CoreSight trace ID and associate with a CPU.
  *
@@ -78,19 +58,27 @@ struct coresight_trace_id_map {
  */
 int coresight_trace_id_get_cpu_id(int cpu);
 
+/**
+ * Version of coresight_trace_id_get_cpu_id() that allows the ID map to operate
+ * on to be provided.
+ */
+int coresight_trace_id_get_cpu_id_map(int cpu, struct coresight_trace_id_map *id_map);
+
 /**
  * Release an allocated trace ID associated with the CPU.
  *
- * This will release the CoreSight trace ID associated with the CPU,
- * unless a perf session is in operation.
- *
- * If a perf session is in operation then the ID will be marked as pending
- * release.
+ * This will release the CoreSight trace ID associated with the CPU.
  *
  * @cpu: The CPU index to release the associated trace ID.
  */
 void coresight_trace_id_put_cpu_id(int cpu);
 
+/**
+ * Version of coresight_trace_id_put_cpu_id() that allows the ID map to operate
+ * on to be provided.
+ */
+void coresight_trace_id_put_cpu_id_map(int cpu, struct coresight_trace_id_map *id_map);
+
 /**
  * Read the current allocated CoreSight Trace ID value for the CPU.
  *
@@ -111,6 +99,12 @@ void coresight_trace_id_put_cpu_id(int cpu);
  */
 int coresight_trace_id_read_cpu_id(int cpu);
 
+/**
+ * Version of coresight_trace_id_read_cpu_id() that allows the ID map to operate
+ * on to be provided.
+ */
+int coresight_trace_id_read_cpu_id_map(int cpu, struct coresight_trace_id_map *id_map);
+
 /**
  * Allocate a CoreSight trace ID for a system component.
  *
@@ -136,21 +130,21 @@ void coresight_trace_id_put_system_id(int id);
 /**
  * Notify the Trace ID allocator that a perf session is starting.
  *
- * Increase the perf session reference count - called by perf when setting up
- * a trace event.
+ * Increase the perf session reference count - called by perf when setting up a
+ * trace event.
  *
- * This reference count is used by the ID allocator to ensure that trace IDs
- * associated with a CPU cannot change or be released during a perf session.
+ * Perf sessions never free trace IDs to ensure that the ID associated with a
+ * CPU cannot change during their and other's concurrent sessions. Instead,
+ * this refcount is used so that the last event to finish always frees all IDs.
  */
-void coresight_trace_id_perf_start(void);
+void coresight_trace_id_perf_start(struct coresight_trace_id_map *id_map);
 
 /**
  * Notify the ID allocator that a perf session is stopping.
  *
- * Decrease the perf session reference count.
- * if this causes the count to go to zero, then all Trace IDs marked as pending
- * release, will be released.
+ * Decrease the perf session reference count. If this causes the count to go to
+ * zero, then all Trace IDs will be released.
  */
-void coresight_trace_id_perf_stop(void);
+void coresight_trace_id_perf_stop(struct coresight_trace_id_map *id_map);
 
 #endif /* _CORESIGHT_TRACE_ID_H */

include/linux/coresight-pmu.h

@@ -49,12 +49,21 @@
  * Interpretation of the PERF_RECORD_AUX_OUTPUT_HW_ID payload.
  * Used to associate a CPU with the CoreSight Trace ID.
  * [07:00] - Trace ID - uses 8 bits to make value easy to read in file.
- * [59:08] - Unused (SBZ)
- * [63:60] - Version
+ * [39:08] - Sink ID - as reported in /sys/bus/event_source/devices/cs_etm/sinks/
+ *	      Added in minor version 1.
+ * [55:40] - Unused (SBZ)
+ * [59:56] - Minor Version - previously existing fields are compatible with
+ *	      all minor versions.
+ * [63:60] - Major Version - previously existing fields mean different things
+ *	      in new major versions.
  */
 #define CS_AUX_HW_ID_TRACE_ID_MASK	GENMASK_ULL(7, 0)
-#define CS_AUX_HW_ID_VERSION_MASK	GENMASK_ULL(63, 60)
+#define CS_AUX_HW_ID_SINK_ID_MASK	GENMASK_ULL(39, 8)
 
-#define CS_AUX_HW_ID_CURR_VERSION 0
+#define CS_AUX_HW_ID_MINOR_VERSION_MASK	GENMASK_ULL(59, 56)
+#define CS_AUX_HW_ID_MAJOR_VERSION_MASK	GENMASK_ULL(63, 60)
+
+#define CS_AUX_HW_ID_MAJOR_VERSION 0
+#define CS_AUX_HW_ID_MINOR_VERSION 1
 
 #endif

include/linux/coresight.h

@@ -218,6 +218,24 @@ struct coresight_sysfs_link {
 	const char *target_name;
 };
 
+/* architecturally we have 128 IDs some of which are reserved */
+#define CORESIGHT_TRACE_IDS_MAX 128
+
+/**
+ * Trace ID map.
+ *
+ * @used_ids:	Bitmap to register available (bit = 0) and in use (bit = 1) IDs.
+ *		Initialised so that the reserved IDs are permanently marked as
+ *		in use.
+ * @perf_cs_etm_session_active: Number of Perf sessions using this ID map.
+ */
+struct coresight_trace_id_map {
+	DECLARE_BITMAP(used_ids, CORESIGHT_TRACE_IDS_MAX);
+	atomic_t __percpu *cpu_map;
+	atomic_t perf_cs_etm_session_active;
+	spinlock_t lock;
+};
+
 /**
  * struct coresight_device - representation of a device as used by the framework
  * @pdata:	Platform data with device connections associated to this device.
@@ -271,6 +289,7 @@ struct coresight_device {
 	bool sysfs_sink_activated;
 	struct dev_ext_attribute *ea;
 	struct coresight_device *def_sink;
+	struct coresight_trace_id_map perf_sink_id_map;
 	/* sysfs links between components */
 	int nr_links;
 	bool has_conns_grp;
@@ -365,7 +384,7 @@ struct coresight_ops_link {
 struct coresight_ops_source {
 	int (*cpu_id)(struct coresight_device *csdev);
 	int (*enable)(struct coresight_device *csdev, struct perf_event *event,
-		      enum cs_mode mode);
+		      enum cs_mode mode, struct coresight_trace_id_map *id_map);
 	void (*disable)(struct coresight_device *csdev,
 			struct perf_event *event);
 };