[PATCH V6 13/26] coresight: etm3x: implementing user/kernel mode tracing

Mathieu Poirier
2015-12-03T21:11:41Z

Adding new mode to limit tracing to kernel or user space.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
drivers/hwtracing/coresight/coresight-etm.h | 7 ++-
.../hwtracing/coresight/coresight-etm3x-sysfs.c | 4 ++
drivers/hwtracing/coresight/coresight-etm3x.c | 63 ++++++++++++++++++++++
drivers/hwtracing/coresight/coresight-priv.h | 3 ++
4 files changed, 76 insertions(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h
index f01862fc98dd..e72815073b63 100644
--- a/drivers/hwtracing/coresight/coresight-etm.h
+++ b/drivers/hwtracing/coresight/coresight-etm.h
@@ -110,7 +110,10 @@
#define ETM_MODE_STALL BIT(2)
#define ETM_MODE_TIMESTAMP BIT(3)
#define ETM_MODE_CTXID BIT(4)
-#define ETM_MODE_ALL 0x1f
+#define ETM_MODE_ALL (ETM_MODE_EXCLUDE | ETM_MODE_CYCACC | \
+ ETM_MODE_STALL | ETM_MODE_TIMESTAMP | \
+ ETM_MODE_CTXID | ETM_MODE_EXCL_KERN | \
+ ETM_MODE_EXCL_USER)

#define ETM_SQR_MASK 0x3
#define ETM_TRACEID_MASK 0x3f
@@ -296,5 +299,7 @@ static inline unsigned int etm_readl(struct etm_drvdata *drvdata, u32 off)
extern const struct attribute_group *coresight_etm_groups[];
int etm_get_trace_id(struct etm_drvdata *drvdata);
void etm_set_default(struct etm_config *config);
+void etm_config_trace_mode(struct etm_drvdata *drvdata,
+ struct etm_config *config, u32 mode);
struct etm_config *get_etm_config(struct etm_drvdata *drvdata);
#endif
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
index 6da50d94ec6f..f7318f04118d 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
@@ -176,6 +176,10 @@ static ssize_t mode_store(struct device *dev,
config->ctrl |= ETMCR_CTXID_SIZE;
else
config->ctrl &= ~ETMCR_CTXID_SIZE;
+
+ if (config->mode & (ETM_MODE_EXCL_KERN | ETM_MODE_EXCL_USER))
+ etm_config_trace_mode(drvdata, config, config->mode);
+
spin_unlock(&drvdata->spinlock);

return size;
diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c
index 14927da0f6ba..d0b77be51980 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x.c
@@ -252,6 +252,69 @@ void etm_set_default(struct etm_config *config)
config->ctxid_mask = 0x0;
}

+void etm_config_trace_mode(struct etm_drvdata *drvdata,
+ struct etm_config *config,
+ u32 mode)
+{
+ u32 flags;
+
+ mode &= (ETM_MODE_EXCL_KERN | ETM_MODE_EXCL_USER);
+
+ /* excluding kernel AND user space doesn't make sense */
+ if (mode == (ETM_MODE_EXCL_KERN | ETM_MODE_EXCL_USER))
+ return;
+
+ /* nothing to do if neither flags are set */
+ if (!(mode & ETM_MODE_EXCL_KERN) && !(mode & ETM_MODE_EXCL_USER))
+ return;
+
+ flags = (1 << 0 | /* instruction execute */
+ 3 << 3 | /* ARM instruction */
+ 0 << 5 | /* No data value comparison */
+ 0 << 7 | /* No exact mach */
+ 0 << 8); /* Ignore context ID */
+
+ /* No need to worry about single address comparators. */
+ config->enable_ctrl2 = 0x0;
+
+ /* Bit 0 is address range comparator 1 */
+ config->enable_ctrl1 = ETMTECR1_ADDR_COMP_1;
+
+ /*
+ * On ETMv3.5:
+ * ETMACTRn[13,11] == Non-secure state comparison control
+ * ETMACTRn[12,10] == Secure state comparison control
+ *
+ * b00 == Match in all modes in this state
+ * b01 == Do not match in any more in this state
+ * b10 == Match in all modes excepts user mode in this state
+ * b11 == Match only in user mode in this state
+ */
+
+ /* Tracing in secure mode is not supported at this time */
+ flags |= (0 << 12 | 1 << 10);
+
+ if (mode & ETM_MODE_EXCL_USER) {
+ /* exclude user, match all modes except user mode */
+ flags |= (1 << 13 | 0 << 11);
+ } else {
+ /* exclude kernel, match only in user mode */
+ flags |= (1 << 13 | 1 << 11);
+ }
+
+ /*
+ * The ETMEEVR register is already set to "hard wire A". As such
+ * all there is to do is setup an address comparator that spans
+ * the entire address range and configure the state and mode bits.
+ */
+ config->addr_val[0] = (u32) 0x0;
+ config->addr_val[1] = (u32) ~0x0;
+ config->addr_acctype[0] = flags;
+ config->addr_acctype[1] = flags;
+ config->addr_type[0] = ETM_ADDR_TYPE_RANGE;
+ config->addr_type[1] = ETM_ADDR_TYPE_RANGE;
+}
+
static void etm_enable_hw(void *info)
{
int i;
diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
index ed116b303e87..932f34a84d96 100644
--- a/drivers/hwtracing/coresight/coresight-priv.h
+++ b/drivers/hwtracing/coresight/coresight-priv.h
@@ -34,6 +34,9 @@
#define TIMEOUT_US 100
#define BMVAL(val, lsb, msb) ((val & GENMASK(msb, lsb)) >> lsb)

+#define ETM_MODE_EXCL_KERN BIT(30)
+#define ETM_MODE_EXCL_USER BIT(31)
+
enum cs_mode {
CS_MODE_DISABLED,
CS_MODE_SYSFS,
--
2.1.4