ARM: etm: Add sysfs entry to set context-id-size
Change-Id: I520dfb6e593dac131de8b9b1db77f1c734f18c24
Signed-off-by: Arve Hjønnevåg <arve@android.com>
diff --git a/arch/arm/kernel/etm.c b/arch/arm/kernel/etm.c
index 460a7d8..f00a3f39 100644
--- a/arch/arm/kernel/etm.c
+++ b/arch/arm/kernel/etm.c
@@ -43,6 +43,7 @@
unsigned long flags;
int ncmppairs;
int etm_portsz;
+ int etm_contextid_size;
u32 etb_fc;
unsigned long range_start;
unsigned long range_end;
@@ -109,6 +110,7 @@
unsigned long timeout = TRACER_TIMEOUT;
v = ETMCTRL_OPTS | ETMCTRL_PROGRAM | ETMCTRL_PORTSIZE(t->etm_portsz);
+ v |= ETMCTRL_CONTEXTIDSIZE(t->etm_contextid_size);
if (t->flags & TRACER_CYCLE_ACC)
v |= ETMCTRL_CYCLEACCURATE;
@@ -650,6 +652,37 @@
static struct kobj_attribute trace_mode_attr =
__ATTR(trace_mode, 0644, trace_mode_show, trace_mode_store);
+static ssize_t trace_contextid_size_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ /* 0: No context id tracing, 1: One byte, 2: Two bytes, 3: Four bytes */
+ return sprintf(buf, "%d\n", (1 << tracer.etm_contextid_size) >> 1);
+}
+
+static ssize_t trace_contextid_size_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t n)
+{
+ unsigned int contextid_size;
+
+ if (sscanf(buf, "%u", &contextid_size) != 1)
+ return -EINVAL;
+
+ if (contextid_size == 3 || contextid_size > 4)
+ return -EINVAL;
+
+ mutex_lock(&tracer.mutex);
+ tracer.etm_contextid_size = fls(contextid_size);
+ mutex_unlock(&tracer.mutex);
+
+ return n;
+}
+
+static struct kobj_attribute trace_contextid_size_attr =
+ __ATTR(trace_contextid_size, 0644,
+ trace_contextid_size_show, trace_contextid_size_store);
+
static ssize_t trace_timestamp_show(struct kobject *kobj,
struct kobj_attribute *attr,
char *buf)
@@ -789,6 +822,7 @@
t->flags = TRACER_CYCLE_ACC | TRACER_TRACE_DATA;
t->etm_portsz = 1;
+ t->etm_contextid_size = 3;
etm_unlock(t, t->etm_regs_count);
(void)etm_readl(t, t->etm_regs_count, ETMMR_PDSR);
@@ -821,6 +855,12 @@
if (ret)
dev_dbg(&dev->dev, "Failed to create trace_mode in sysfs\n");
+ ret = sysfs_create_file(&dev->dev.kobj,
+ &trace_contextid_size_attr.attr);
+ if (ret)
+ dev_dbg(&dev->dev,
+ "Failed to create trace_contextid_size in sysfs\n");
+
if (etmccer & ETMCCER_TIMESTAMPING_IMPLEMENTED) {
ret = sysfs_create_file(&dev->dev.kobj,
&trace_timestamp_attr.attr);