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/include/asm/hardware/coresight.h b/arch/arm/include/asm/hardware/coresight.h
index 42059d36f3aa3a4b189f37e9b51aee43259d2691..47b7696845556291cae2fc2d13d4c091e548d9f5 100644 (file)
--- a/arch/arm/include/asm/hardware/coresight.h
+++ b/arch/arm/include/asm/hardware/coresight.h
@@ -47,7 +47,7 @@
 #define ETMCTRL_POWERDOWN      1
 #define ETMCTRL_PROGRAM                (1 << 10)
 #define ETMCTRL_PORTSEL                (1 << 11)
-#define ETMCTRL_DO_CONTEXTID   (3 << 14)
+#define ETMCTRL_CONTEXTIDSIZE(x) (((x) & 3) << 14)
 #define ETMCTRL_PORTMASK1      (7 << 4)
 #define ETMCTRL_PORTMASK2      (1 << 21)
 #define ETMCTRL_PORTMASK       (ETMCTRL_PORTMASK1 | ETMCTRL_PORTMASK2)
@@ -127,8 +127,7 @@
 #define ETMVDC3_EXCLONLY       BIT(16)
 
 #define ETMCTRL_OPTS           (ETMCTRL_DO_CPRT | \
-                               ETMCTRL_BRANCH_OUTPUT | \
-                               ETMCTRL_DO_CONTEXTID)
+                               ETMCTRL_BRANCH_OUTPUT)
 
 #define ETMR_ID                        0x1e4
 #define ETMIDR_VERSION(x)      (((x) >> 4) & 0xff)

diff --git a/arch/arm/kernel/etm.c b/arch/arm/kernel/etm.c
index d83ba792dcedafa0818fc8c25bb21171444717b3..9cba22d2047c8e2eb912ac8a3625d9d255a3d37b 100644 (file)
--- a/arch/arm/kernel/etm.c
+++ b/arch/arm/kernel/etm.c
@@ -42,6 +42,7 @@ struct tracectx {
        unsigned long   flags;
        int             ncmppairs;
        int             etm_portsz;
+       int             etm_contextid_size;
        u32             etb_fc;
        unsigned long   range_start;
        unsigned long   range_end;
@@ -108,6 +109,7 @@ static int trace_start_etm(struct tracectx *t, int id)
        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;
@@ -649,6 +651,37 @@ static ssize_t trace_mode_store(struct kobject *kobj,
 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)
@@ -788,6 +821,7 @@ static int __devinit etm_probe(struct amba_device *dev, const struct amba_id *id
 
        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);
@@ -820,6 +854,12 @@ static int __devinit 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 = 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);