net: ipa: support different event ring encoding

Starting with IPA v5.0, a channel's event ring index is encoded in
a field in the CH_C_CNTXT_1 GSI register rather than CH_C_CNTXT_0.
Define a new field ID for the former register and encode the event
ring in the appropriate register.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ipa/gsi.c

@@ -840,12 +840,15 @@ static void gsi_channel_program(struct gsi_channel *channel, bool doorbell)
 	val = ch_c_cntxt_0_type_encode(gsi->version, reg, GSI_CHANNEL_TYPE_GPI);
 	if (channel->toward_ipa)
 		val |= reg_bit(reg, CHTYPE_DIR);
-	val |= reg_encode(reg, ERINDEX, channel->evt_ring_id);
+	if (gsi->version < IPA_VERSION_5_0)
+		val |= reg_encode(reg, ERINDEX, channel->evt_ring_id);
 	val |= reg_encode(reg, ELEMENT_SIZE, GSI_RING_ELEMENT_SIZE);
 	iowrite32(val, gsi->virt + reg_n_offset(reg, channel_id));
 
 	reg = gsi_reg(gsi, CH_C_CNTXT_1);
 	val = reg_encode(reg, CH_R_LENGTH, size);
+	if (gsi->version >= IPA_VERSION_5_0)
+		val |= reg_encode(reg, CH_ERINDEX, channel->evt_ring_id);
 	iowrite32(val, gsi->virt + reg_n_offset(reg, channel_id));
 
 	/* The context 2 and 3 registers store the low-order and

drivers/net/ipa/gsi_reg.h

@@ -102,7 +102,7 @@ enum gsi_reg_ch_c_cntxt_0_field_id {
 	CH_EE,
 	CHID,
 	CHTYPE_PROTOCOL_MSB,				/* IPA v4.5-4.11 */
-	ERINDEX,
+	ERINDEX,					/* Not IPA v5.0+ */
 	CHSTATE,
 	ELEMENT_SIZE,
 };
@@ -124,6 +124,7 @@ enum gsi_channel_type {
 /* CH_C_CNTXT_1 register */
 enum gsi_reg_ch_c_cntxt_1_field_id {
 	CH_R_LENGTH,
+	CH_ERINDEX,					/* IPA v5.0+ */
 };
 
 /* CH_C_QOS register */