Hi,

On Wed, 9 Feb 2022 at 10:57, Mao Jinlong quic_jinlmao@quicinc.com wrote:

Except from STM and ETM/ETE, there could be other sources. Each source needs a unique trace id. Define a bitmap for the trace ids. The position of each bit represents trace id of the source.

Signed-off-by: Mao Jinlong quic_jinlmao@quicinc.com

drivers/hwtracing/coresight/coresight-core.c | 48 ++++++++++++++++++++ include/linux/coresight-pmu.h | 11 +++++ 2 files changed, 59 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index a90097f88425..6cb55c3f41d5 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -16,6 +16,7 @@ #include <linux/mutex.h> #include <linux/clk.h> #include <linux/coresight.h> +#include <linux/coresight-pmu.h>

see my comment below about using coresigh-priv.h

#include <linux/of_platform.h> #include <linux/delay.h> #include <linux/pm_runtime.h> @@ -25,8 +26,11 @@ #include "coresight-syscfg.h"

static DEFINE_MUTEX(coresight_mutex); +static DEFINE_MUTEX(coresight_id_mutex); static DEFINE_PER_CPU(struct coresight_device *, csdev_sink);

+static DECLARE_BITMAP(coresight_trace_id, CORESIGHT_TRACE_ID_NUM);

/*

• Use IDR to map the hash length of the source's device name
• to the pointer of path for the source

@@ -51,6 +55,48 @@ struct coresight_node { const u32 coresight_barrier_pkt[4] = {0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff}; EXPORT_SYMBOL_GPL(coresight_barrier_pkt);

+/* Init the coresight_trace_id bit map. */ +static void coresight_init_trace_id(void) +{

•   int i;
  

•   /* Trace id 0 is invalid. */
  

•   set_bit(CORESIGHT_TRACE_ID_0, coresight_trace_id);
  

•   /* Trace id 1 is fixed for STM. */
  

•   set_bit(CORESIGHT_TRACE_ID_1, coresight_trace_id);
  

•   /* Trace id from 112 to 127 are reserved. */
  

•   for (i = CORESIGHT_TRACE_ID_112; i <= CORESIGHT_TRACE_ID_127; i++)
  

•           set_bit(i, coresight_trace_id);
  

•   /* Skip the trace ids of ETM/ETE. */
  

•   for (i = 0; i <= cpumask_last(cpu_possible_mask); i++)
  

•           set_bit(coresight_get_trace_id(i), coresight_trace_id);
  

+}

+/*

• • Return the first zero bit position of bitmap coresight_trace_id
• • as source's trace id.
• */

+int coresight_get_system_trace_id(void) +{

•   int id;
  

•   mutex_lock(&coresight_id_mutex);
  

•   id = find_first_zero_bit(coresight_trace_id, CORESIGHT_TRACE_ID_NUM);
  

•   /* If no zero bit is found, return error value. */
  

•   if (id == CORESIGHT_TRACE_ID_NUM) {
  

•           mutex_unlock(&coresight_id_mutex);
  

•           return -EINVAL;
  

•   }
  

•   set_bit(id, coresight_trace_id);
  

•   mutex_unlock(&coresight_id_mutex);
  

•   return id;
  

+} +EXPORT_SYMBOL(coresight_get_system_trace_id);

static const struct cti_assoc_op *cti_assoc_ops;

void coresight_set_cti_ops(const struct cti_assoc_op *cti_op) @@ -1750,6 +1796,8 @@ static int __init coresight_init(void) return 0;

    etm_perf_exit();

•   coresight_init_trace_id();
  

exit_bus_unregister: bus_unregister(&coresight_bustype); return ret; diff --git a/include/linux/coresight-pmu.h b/include/linux/coresight-pmu.h index 4ac5c081af93..1e2c5ca4c6e6 100644 --- a/include/linux/coresight-pmu.h +++ b/include/linux/coresight-pmu.h @@ -32,6 +32,14 @@ #define ETM4_CFG_BIT_RETSTK 12 #define ETM4_CFG_BIT_VMID_OPT 15

The following additional defines and function should appear in coresight-priv.h The coresight-pmu.h file contains data for the interface between the drivers and perf.

+/* Coresight component supports 7 bits trace id. */

additional comment here to explain that 0, 0x70- 0x7F IDs are reserved by the architecture, 1 is default for STM

+#define CORESIGHT_TRACE_ID_NUM 128

+#define CORESIGHT_TRACE_ID_0 0 +#define CORESIGHT_TRACE_ID_1 1 +#define CORESIGHT_TRACE_ID_112 112 +#define CORESIGHT_TRACE_ID_127 127

can we have these names a little more descriptive - e.g. CORESIGHT_TRACE_ID_0_RES 0 CORESIGHT_TRACE_ID_STM 1 CORESIGHT_TRACE_ID_RANGE_LO_RES 0x70 CORESIGHT_TRACE_ID_RANGE_HI_RES 0x7F

Additionally - now we are declaring a #define for the STM ID - it would be better to use that in coresight-stm.c stm_init_default_data() to set the trace id for the STM.

Regards

Mike

static inline int coresight_get_trace_id(int cpu) { /* @@ -43,4 +51,7 @@ static inline int coresight_get_trace_id(int cpu) return (CORESIGHT_ETM_PMU_SEED + (cpu * 2)); }

+/* Get the trace id for the sources except from STM, ETM/ETE. */ +extern int coresight_get_system_trace_id(void);

#endif

2.17.1