In the same manner as for enabling tracing, an entry is created
in sysfs to set the address range that triggers tracing.
Signed-off-by: Adrien Vergé <adrienve...@gmail.com>
---
arch/arm/kernel/etm.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 49 insertions(+), 3 deletions(-)
diff --git a/arch/arm/kernel/etm.c b/arch/arm/kernel/etm.c
index 7f7a0ee..4442e5c 100644
--- a/arch/arm/kernel/etm.c
+++ b/arch/arm/kernel/etm.c
@@ -44,6 +44,8 @@ struct tracectx {
struct device *dev;
struct clk *emu_clk;
struct mutex mutex;
+ unsigned long addrrange_start;
+ unsigned long addrrange_end;
};
static struct tracectx tracer;
@@ -53,6 +55,13 @@ static inline bool trace_isrunning(struct tracectx *t)
return !!(t->flags & TRACER_RUNNING);
}
+/*
+ * Setups ETM to trace only when:
+ * - address between start and end
+ * or address not between start and end (if exclude)
+ * - trace executed instructions
+ * or trace loads and stores (if data)
+ */
static int etm_setup_address_range(struct tracectx *t, int n,
unsigned long start, unsigned long end, int exclude, int data)
{
@@ -115,8 +124,8 @@ static int trace_start(struct tracectx *t)
return -EFAULT;
}
- etm_setup_address_range(t, 1, (unsigned long)_stext,
- (unsigned long)_etext, 0, 0);
+ etm_setup_address_range(t, 1, t->addrrange_start, t->addrrange_end,
+ 0, 0);
etm_writel(t, 0, ETMR_TRACEENCTRL2);
etm_writel(t, 0, ETMR_TRACESSCTRL);
etm_writel(t, 0x6f, ETMR_TRACEENEVT);
@@ -527,6 +536,36 @@ static ssize_t trace_mode_store(struct device *dev,
DEVICE_ATTR(trace_mode, S_IRUGO|S_IWUSR, trace_mode_show, trace_mode_store);
+static ssize_t trace_addrrange_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%08lx - %08lx\n", tracer.addrrange_start,
+ tracer.addrrange_end);
+}
+
+static ssize_t trace_addrrange_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t n)
+{
+ unsigned long start, end;
+
+ if (tracer.flags & TRACER_RUNNING)
+ return -EBUSY;
+
+ if (sscanf(buf, "%08lx - %08lx", &start, &end) != 2)
+ return -EINVAL;
+
+ mutex_lock(&tracer.mutex);
+ tracer.addrrange_start = start;
+ tracer.addrrange_end = end;
+ mutex_unlock(&tracer.mutex);
+
+ return n;
+}
+
+DEVICE_ATTR(trace_addrrange, S_IRUGO|S_IWUSR,
+ trace_addrrange_show, trace_addrrange_store);
+
static int etm_probe(struct amba_device *dev, const struct amba_id *id)
{
struct tracectx *t = &tracer;
@@ -554,6 +593,8 @@ static int etm_probe(struct amba_device *dev, const struct
amba_id *id)
t->dev = &dev->dev;
t->flags = TRACER_CYCLE_ACC;
t->etm_portsz = 1;
+ t->addrrange_start = (unsigned long) _stext;
+ t->addrrange_end = (unsigned long) _etext;
etm_unlock(t);
(void)etm_readl(t, ETMMR_PDSR);
@@ -568,7 +609,7 @@ static int etm_probe(struct amba_device *dev, const struct
amba_id *id)
if (ret)
goto out_unmap;
- /* failing to create any of these two is not fatal */
+ /* failing to create any of these three is not fatal */
ret = device_create_file(&dev->dev, &dev_attr_trace_info);
if (ret)
dev_dbg(&dev->dev, "Failed to create trace_info in sysfs\n");
@@ -577,6 +618,10 @@ static int etm_probe(struct amba_device *dev, const struct
amba_id *id)
if (ret)
dev_dbg(&dev->dev, "Failed to create trace_mode in sysfs\n");
+ ret = device_create_file(&dev->dev, &dev_attr_trace_addrrange);
+ if (ret)
+ dev_dbg(&dev->dev, "Failed to create trace_addrrange in
sysfs\n");
+
dev_dbg(t->dev, "ETM AMBA driver initialized.\n");
out:
@@ -606,6 +651,7 @@ static int etm_remove(struct amba_device *dev)
device_remove_file(&dev->dev, &dev_attr_trace_running);
device_remove_file(&dev->dev, &dev_attr_trace_info);
device_remove_file(&dev->dev, &dev_attr_trace_mode);
+ device_remove_file(&dev->dev, &dev_attr_trace_addrrange);
return 0;
}
--
1.8.5.2
--
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