coresight: etm3x: implementing user/kernel mode tracing

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

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 63 insertions, 0 deletions

diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c b/drivers/hwtracing/coresight/coresight-etm3x.c
index 34a69583ccbc..c82d545e68ef 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x.c
@@ -234,6 +234,69 @@ void etm_set_default(struct etm_config *config)
 	config->ctxid_mask = 0x0;
 }
 
+void etm_config_trace_mode(struct etm_config *config)
+{
+	u32 flags, mode;
+
+	mode = config->mode;
+
+	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;