net: mvpp2: cls: Write C2 TCAM data last when writing a C2 entry

When writing a C2 entry to hardware, some registers writes will only
take effect when the TCAM_DATA4 register is written. This includes all
C2 TCAM registers, and the C2 invalidate register.

To make sure we always write C2 entries correctly, document that
behaviour with a comment, and move TCAM writes to the end of the
mvpp2_cls_c2_write helper.

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

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_cls.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_cls.c
index 96358ef..335714e 100644 (file)
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_cls.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_cls.c
@@ -748,19 +748,19 @@ static void mvpp2_cls_c2_write(struct mvpp2 *priv,
 {
        mvpp2_write(priv, MVPP22_CLS_C2_TCAM_IDX, c2->index);
 
-       /* Write TCAM */
-       mvpp2_write(priv, MVPP22_CLS_C2_TCAM_DATA0, c2->tcam[0]);
-       mvpp2_write(priv, MVPP22_CLS_C2_TCAM_DATA1, c2->tcam[1]);
-       mvpp2_write(priv, MVPP22_CLS_C2_TCAM_DATA2, c2->tcam[2]);
-       mvpp2_write(priv, MVPP22_CLS_C2_TCAM_DATA3, c2->tcam[3]);
-       mvpp2_write(priv, MVPP22_CLS_C2_TCAM_DATA4, c2->tcam[4]);
-
        mvpp2_write(priv, MVPP22_CLS_C2_ACT, c2->act);
 
        mvpp2_write(priv, MVPP22_CLS_C2_ATTR0, c2->attr[0]);
        mvpp2_write(priv, MVPP22_CLS_C2_ATTR1, c2->attr[1]);
        mvpp2_write(priv, MVPP22_CLS_C2_ATTR2, c2->attr[2]);
        mvpp2_write(priv, MVPP22_CLS_C2_ATTR3, c2->attr[3]);
+
+       mvpp2_write(priv, MVPP22_CLS_C2_TCAM_DATA0, c2->tcam[0]);
+       mvpp2_write(priv, MVPP22_CLS_C2_TCAM_DATA1, c2->tcam[1]);
+       mvpp2_write(priv, MVPP22_CLS_C2_TCAM_DATA2, c2->tcam[2]);
+       mvpp2_write(priv, MVPP22_CLS_C2_TCAM_DATA3, c2->tcam[3]);
+       /* Writing TCAM_DATA4 flushes writes to TCAM_DATA0-4 and INV to HW */
+       mvpp2_write(priv, MVPP22_CLS_C2_TCAM_DATA4, c2->tcam[4]);
 }
 
 void mvpp2_cls_c2_read(struct mvpp2 *priv, int index,