net: mvpp2: debugfs: add hit counter stats for Header Parser entries

One helpful feature to help debug the Header Parser TCAM filter in PPv2
is to be able to see if the entries did match something when a packet
comes in. This can be done by using the built-in hit counter for TCAM
entries.

This commit implements reading the counter, and exposing its value on
debugfs for each filter entry.

The counter is a 16-bits clear-on-read value, located at:
 .../mvpp2/<controller>/parser/XXX/hits

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.c
index f133d820f0fa..392fd895f278 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.c
@@ -2478,3 +2478,19 @@ int mvpp2_prs_def_flow(struct mvpp2_port *port)
 
 	return 0;
 }
+
+int mvpp2_prs_hits(struct mvpp2 *priv, int index)
+{
+	u32 val;
+
+	if (index > MVPP2_PRS_TCAM_SRAM_SIZE)
+		return -EINVAL;
+
+	mvpp2_write(priv, MVPP2_PRS_TCAM_HIT_IDX_REG, index);
+
+	val = mvpp2_read(priv, MVPP2_PRS_TCAM_HIT_CNT_REG);
+
+	val &= MVPP2_PRS_TCAM_HIT_CNT_MASK;
+
+	return val;
+}