Thread (21 messages) 21 messages, 3 authors, 2025-04-11

Re: [PATCH v3 4/7] coresight-tgu: Add TGU decode support

From: Mike Leach <hidden>
Date: 2025-03-07 10:58:34
Also in: linux-arm-msm, linux-devicetree, lkml

Hi,

On Thu, 27 Feb 2025 at 09:27, songchai [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: Songwei Chai <redacted>

Decoding is when all the potential pieces for creating a trigger
are brought together for a given step. Example - there may be a
counter keeping track of some occurrences and a priority-group that
is being used to detect a pattern on the sense inputs. These 2
inputs to condition_decode must be programmed, for a given step,
to establish the condition for the trigger, or movement to another
step.

Signed-off-by: Songwei Chai <redacted>
Signed-off-by: songchai <redacted>
---
 .../testing/sysfs-bus-coresight-devices-tgu   |   7 ++
 drivers/hwtracing/coresight/coresight-tgu.c   | 113 ++++++++++++++++--
 drivers/hwtracing/coresight/coresight-tgu.h   |  29 ++++-
 3 files changed, 136 insertions(+), 13 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tgu b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tgu
index af7332153833..dd6cc1184d52 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tgu
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tgu
@@ -14,3 +14,10 @@ KernelVersion   6.15
 Contact:        Jinlong Mao (QUIC) <quic_jinlmao@quicinc.com>, Sam Chai (QUIC) <quic_songchai@quicinc.com>
 Description:
                 (RW) Set/Get the sensed siganal with specific step and priority for TGU.
+
+What:           /sys/bus/coresight/devices/<tgu-name>/step[0:7]_condition_decode/reg[0:3]
+Date:           February 2025
+KernelVersion   6.15
+Contact:        Jinlong Mao (QUIC) <quic_jinlmao@quicinc.com>, Sam Chai (QUIC) <quic_songchai@quicinc.com>
+Description:
+                (RW) Set/Get the decode mode with specific step for TGU.
diff --git a/drivers/hwtracing/coresight/coresight-tgu.c b/drivers/hwtracing/coresight/coresight-tgu.c
index f28761619ebe..5eebf5eecbbb 100644
--- a/drivers/hwtracing/coresight/coresight-tgu.c
+++ b/drivers/hwtracing/coresight/coresight-tgu.c
@@ -22,9 +22,21 @@ static int calculate_array_location(struct tgu_drvdata *drvdata, int step_index,
 {
        int ret = -EINVAL;

-       ret = operation_index * (drvdata->max_step) *
-                     (drvdata->max_reg) + step_index * (drvdata->max_reg)
-                               + reg_index;
+       switch (operation_index) {
+       case TGU_PRIORITY0:
+       case TGU_PRIORITY1:
+       case TGU_PRIORITY2:
+       case TGU_PRIORITY3:
+               ret = operation_index * (drvdata->max_step) *
+                       (drvdata->max_reg) + step_index * (drvdata->max_reg)
+                       + reg_index;
+               break;
+       case TGU_CONDITION_DECODE:
+               ret = step_index * (drvdata->max_condition_decode) + reg_index;
+               break;
+       default:
+               break;
+       }

        return ret;
 }
@@ -36,10 +48,23 @@ static ssize_t tgu_dataset_show(struct device *dev,
        struct tgu_attribute *tgu_attr =
                container_of(attr, struct tgu_attribute, attr);

-       return sysfs_emit(buf, "0x%x\n",
-                         drvdata->value_table->priority[calculate_array_location(
+       switch (tgu_attr->operation_index) {
+       case TGU_PRIORITY0:
+       case TGU_PRIORITY1:
+       case TGU_PRIORITY2:
+       case TGU_PRIORITY3:
+               return sysfs_emit(buf, "0x%x\n",
+                                 drvdata->value_table->priority[calculate_array_location(
calculate_array_location() can return -EINVAL - you could be
referencing array value drvdata->value_table->priority[-EINVAL] here.
Test the return before referencing the array.

Same for all following occurrences.

                                  drvdata, tgu_attr->step_index,
                                  tgu_attr->operation_index, tgu_attr->reg_num)]);
+       case TGU_CONDITION_DECODE:
+               return sysfs_emit(buf, "0x%x\n",
+                                 drvdata->value_table->condition_decode[calculate_array_location(
+                                 drvdata, tgu_attr->step_index, tgu_attr->operation_index,
+                                 tgu_attr->reg_num)]);
+
missing default - did this code compile without warnings?
quoted hunk ↗ jump to hunk
+       }
+       return -EINVAL;

 }
@@ -58,11 +83,25 @@ static ssize_t tgu_dataset_store(struct device *dev,
                return ret;

        guard(spinlock)(&tgu_drvdata->spinlock);
-       tgu_drvdata->value_table->priority[calculate_array_location(
-               tgu_drvdata, tgu_attr->step_index, tgu_attr->operation_index,
-               tgu_attr->reg_num)] = val;
-       ret = size;
-
+       switch (tgu_attr->operation_index) {
+       case TGU_PRIORITY0:
+       case TGU_PRIORITY1:
+       case TGU_PRIORITY2:
+       case TGU_PRIORITY3:
+               tgu_drvdata->value_table->priority[calculate_array_location(
+                       tgu_drvdata, tgu_attr->step_index, tgu_attr->operation_index,
+                       tgu_attr->reg_num)] = val;
+               ret = size;
+               break;
+       case TGU_CONDITION_DECODE:
+               tgu_drvdata->value_table->condition_decode[calculate_array_location(
+                       tgu_drvdata, tgu_attr->step_index, tgu_attr->operation_index,
+                       tgu_attr->reg_num)] = val;
+               ret = size;
+               break;
+       default:
+               break;
+       }
        return ret;
 }
@@ -79,8 +118,23 @@ static umode_t tgu_node_visible(struct kobject *kobject, struct attribute *attr,
                container_of(dev_attr, struct tgu_attribute, attr);

        if (tgu_attr->step_index < drvdata->max_step) {
-               ret = (tgu_attr->reg_num < drvdata->max_reg) ?
-                                           attr->mode : 0;
+               switch (tgu_attr->operation_index) {
+               case TGU_PRIORITY0:
+               case TGU_PRIORITY1:
+               case TGU_PRIORITY2:
+               case TGU_PRIORITY3:
+                       ret = (tgu_attr->reg_num < drvdata->max_reg) ?
+                                     attr->mode : 0;
+                       break;
+               case TGU_CONDITION_DECODE:
+                       ret = (tgu_attr->reg_num <
+                                       drvdata->max_condition_decode) ?
+                                               attr->mode : 0;
+                       break;
+               default:
+                       break;
+               }
+
                return ret;
        }
        return SYSFS_GROUP_INVISIBLE;
@@ -103,6 +157,17 @@ static void tgu_write_all_hw_regs(struct tgu_drvdata *drvdata)
                }
        }

+       for (i = 0; i < drvdata->max_step; i++) {
+               for (j = 0; j < drvdata->max_condition_decode; j++) {
+                       tgu_writel(drvdata,
+                                  drvdata->value_table
+                                          ->condition_decode[calculate_array_location(
+                                                  drvdata, i,
+                                                  TGU_CONDITION_DECODE, j)],
+                                  CONDITION_DECODE_STEP(i, j));
+               }
+       }
+
        /* Enable TGU to program the triggers */
        tgu_writel(drvdata, 1, TGU_CONTROL);
        CS_LOCK(drvdata->base);
@@ -245,6 +310,14 @@ static const struct attribute_group *tgu_attr_groups[] = {
        PRIORITY_ATTRIBUTE_GROUP_INIT(7, 1),
        PRIORITY_ATTRIBUTE_GROUP_INIT(7, 2),
        PRIORITY_ATTRIBUTE_GROUP_INIT(7, 3),
+       CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(0),
+       CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(1),
+       CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(2),
+       CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(3),
+       CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(4),
+       CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(5),
+       CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(6),
+       CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(7),
        NULL,
 };
@@ -289,6 +362,13 @@ static int tgu_probe(struct amba_device *adev, const struct amba_id *id)
        if (ret)
                return -EINVAL;

+       ret = of_property_read_u32(adev->dev.of_node, "tgu-conditions",
+                                  &drvdata->max_condition);
+       if (ret)
+               return -EINVAL;
+
+       drvdata->max_condition_decode = drvdata->max_condition;
+
        drvdata->value_table =
                devm_kzalloc(dev, sizeof(*drvdata->value_table), GFP_KERNEL);
        if (!drvdata->value_table)
@@ -303,6 +383,15 @@ static int tgu_probe(struct amba_device *adev, const struct amba_id *id)
        if (!drvdata->value_table->priority)
                return -ENOMEM;

+       drvdata->value_table->condition_decode = devm_kzalloc(
+               dev,
+               drvdata->max_condition_decode * drvdata->max_step *
+                       sizeof(*(drvdata->value_table->condition_decode)),
+               GFP_KERNEL);
+
+       if (!drvdata->value_table->condition_decode)
+               return -ENOMEM;
+
        drvdata->enable = false;
        desc.type = CORESIGHT_DEV_TYPE_HELPER;
        desc.pdata = adev->dev.platform_data;
diff --git a/drivers/hwtracing/coresight/coresight-tgu.h b/drivers/hwtracing/coresight/coresight-tgu.h
index 6e5d465117df..c2a9ce38b44f 100644
--- a/drivers/hwtracing/coresight/coresight-tgu.h
+++ b/drivers/hwtracing/coresight/coresight-tgu.h
@@ -46,6 +46,9 @@
 #define PRIORITY_REG_STEP(step, priority, reg)\
        (0x0074 + 0x60 * priority + 0x4 * reg + 0x1D8 * step)

+#define CONDITION_DECODE_STEP(step, decode) \
+       (0x0050 + 0x4 * decode + 0x1D8 * step)
+
use #define constants with explanations of what they are rather than
arbitrary magic numbers.
quoted hunk ↗ jump to hunk
 #define tgu_dataset_ro(name, step_index, type, reg_num)     \
        (&((struct tgu_attribute[]){ {                      \
                __ATTR(name, 0444, tgu_dataset_show, NULL), \
@@ -66,6 +69,9 @@
        tgu_dataset_rw(reg##reg_num, step_index, TGU_PRIORITY##priority, \
                       reg_num)

+#define STEP_DECODE(step_index, reg_num) \
+       tgu_dataset_rw(reg##reg_num, step_index, TGU_CONDITION_DECODE, reg_num)
+
 #define STEP_PRIORITY_LIST(step_index, priority)  \
        {STEP_PRIORITY(step_index, 0, priority),  \
         STEP_PRIORITY(step_index, 1, priority),  \
@@ -88,6 +94,14 @@
         NULL                   \
        }

+#define STEP_DECODE_LIST(n) \
+       {STEP_DECODE(n, 0), \
+        STEP_DECODE(n, 1), \
+        STEP_DECODE(n, 2), \
+        STEP_DECODE(n, 3), \
+        NULL           \
+       }
+
 #define PRIORITY_ATTRIBUTE_GROUP_INIT(step, priority)\
        (&(const struct attribute_group){\
                .attrs = (struct attribute*[])STEP_PRIORITY_LIST(step, priority),\
@@ -95,11 +109,19 @@
                .name = "step" #step "_priority" #priority \
        })

+#define CONDITION_DECODE_ATTRIBUTE_GROUP_INIT(step)\
+       (&(const struct attribute_group){\
+               .attrs = (struct attribute*[])STEP_DECODE_LIST(step),\
+               .is_visible = tgu_node_visible,\
+               .name = "step" #step "_condition_decode" \
+       })
+
 enum operation_index {
        TGU_PRIORITY0,
        TGU_PRIORITY1,
        TGU_PRIORITY2,
-       TGU_PRIORITY3
+       TGU_PRIORITY3,
+       TGU_CONDITION_DECODE

 };
@@ -115,6 +137,7 @@ struct tgu_attribute {

 struct value_table {
        unsigned int *priority;
+       unsigned int *condition_decode;
 };

 /**
@@ -127,6 +150,8 @@ struct value_table {
  * @value_table: Store given value based on relevant parameters.
  * @max_reg: Maximum number of registers
  * @max_step: Maximum step size
+ * @max_condition: Maximum number of condition
+ * @max_condition_decode: Maximum number of condition_decode
  *
  * This structure defines the data associated with a TGU device, including its base
  * address, device pointers, clock, spinlock for synchronization, trigger data pointers,
@@ -141,6 +166,8 @@ struct tgu_drvdata {
        struct value_table *value_table;
        int max_reg;
        int max_step;
+       int max_condition;
+       int max_condition_decode;
 };

 #endif
Regards

Mike

-- 
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help