Merge branch 'net-ipa-limit-special-reset-handling'

Alex Elder says:

====================
net: ipa: limit special reset handling

Some special handling done during channel reset should only be done
for IPA hardare version 3.5.1.  This series generalizes the meaning
of a flag passed to indicate special behavior, then has the special
handling be used only when appropriate.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ipa/gsi.c

@@ -834,18 +834,18 @@ int gsi_channel_stop(struct gsi *gsi, u32 channel_id)
 }
 
 /* Reset and reconfigure a channel (possibly leaving doorbell disabled) */
-void gsi_channel_reset(struct gsi *gsi, u32 channel_id, bool db_enable)
+void gsi_channel_reset(struct gsi *gsi, u32 channel_id, bool legacy)
 {
 	struct gsi_channel *channel = &gsi->channel[channel_id];
 
 	mutex_lock(&gsi->mutex);
 
-	/* Due to a hardware quirk we need to reset RX channels twice. */
 	gsi_channel_reset_command(channel);
-	if (!channel->toward_ipa)
+	/* Due to a hardware quirk we may need to reset RX channels twice. */
+	if (legacy && !channel->toward_ipa)
 		gsi_channel_reset_command(channel);
 
-	gsi_channel_program(channel, db_enable);
+	gsi_channel_program(channel, legacy);
 	gsi_channel_trans_cancel_pending(channel);
 
 	mutex_unlock(&gsi->mutex);
@@ -1455,7 +1455,7 @@ static void gsi_evt_ring_teardown(struct gsi *gsi)
 
 /* Setup function for a single channel */
 static int gsi_channel_setup_one(struct gsi *gsi, u32 channel_id,
-				 bool db_enable)
+				 bool legacy)
 {
 	struct gsi_channel *channel = &gsi->channel[channel_id];
 	u32 evt_ring_id = channel->evt_ring_id;
@@ -1474,7 +1474,7 @@ static int gsi_channel_setup_one(struct gsi *gsi, u32 channel_id,
 	if (ret)
 		goto err_evt_ring_de_alloc;
 
-	gsi_channel_program(channel, db_enable);
+	gsi_channel_program(channel, legacy);
 
 	if (channel->toward_ipa)
 		netif_tx_napi_add(&gsi->dummy_dev, &channel->napi,
@@ -1545,7 +1545,7 @@ static void gsi_modem_channel_halt(struct gsi *gsi, u32 channel_id)
 }
 
 /* Setup function for channels */
-static int gsi_channel_setup(struct gsi *gsi, bool db_enable)
+static int gsi_channel_setup(struct gsi *gsi, bool legacy)
 {
 	u32 channel_id = 0;
 	u32 mask;
@@ -1557,7 +1557,7 @@ static int gsi_channel_setup(struct gsi *gsi, bool db_enable)
 	mutex_lock(&gsi->mutex);
 
 	do {
-		ret = gsi_channel_setup_one(gsi, channel_id, db_enable);
+		ret = gsi_channel_setup_one(gsi, channel_id, legacy);
 		if (ret)
 			goto err_unwind;
 	} while (++channel_id < gsi->channel_count);
@@ -1643,7 +1643,7 @@ static void gsi_channel_teardown(struct gsi *gsi)
 }
 
 /* Setup function for GSI.  GSI firmware must be loaded and initialized */
-int gsi_setup(struct gsi *gsi, bool db_enable)
+int gsi_setup(struct gsi *gsi, bool legacy)
 {
 	u32 val;
 
@@ -1686,7 +1686,7 @@ int gsi_setup(struct gsi *gsi, bool db_enable)
 	/* Writing 1 indicates IRQ interrupts; 0 would be MSI */
 	iowrite32(1, gsi->virt + GSI_CNTXT_INTSET_OFFSET);
 
-	return gsi_channel_setup(gsi, db_enable);
+	return gsi_channel_setup(gsi, legacy);
 }
 
 /* Inverse of gsi_setup() */

drivers/net/ipa/gsi.h

@@ -165,14 +165,14 @@ struct gsi {
 /**
  * gsi_setup() - Set up the GSI subsystem
  * @gsi:	Address of GSI structure embedded in an IPA structure
- * @db_enable:	Whether to use the GSI doorbell engine
+ * @legacy:	Set up for legacy hardware
  *
  * @Return:	0 if successful, or a negative error code
  *
  * Performs initialization that must wait until the GSI hardware is
  * ready (including firmware loaded).
  */
-int gsi_setup(struct gsi *gsi, bool db_enable);
+int gsi_setup(struct gsi *gsi, bool legacy);
 
 /**
  * gsi_teardown() - Tear down GSI subsystem
@@ -220,15 +220,15 @@ int gsi_channel_stop(struct gsi *gsi, u32 channel_id);
  * gsi_channel_reset() - Reset an allocated GSI channel
  * @gsi:	GSI pointer
  * @channel_id:	Channel to be reset
- * @db_enable:	Whether doorbell engine should be enabled
+ * @legacy:	Legacy behavior
  *
- * Reset a channel and reconfigure it.  The @db_enable flag indicates
- * whether the doorbell engine will be enabled following reconfiguration.
+ * Reset a channel and reconfigure it.  The @legacy flag indicates
+ * that some steps should be done differently for legacy hardware.
  *
  * GSI hardware relinquishes ownership of all pending receive buffer
  * transactions and they will complete with their cancelled flag set.
  */
-void gsi_channel_reset(struct gsi *gsi, u32 channel_id, bool db_enable);
+void gsi_channel_reset(struct gsi *gsi, u32 channel_id, bool legacy);
 
 int gsi_channel_suspend(struct gsi *gsi, u32 channel_id, bool stop);
 int gsi_channel_resume(struct gsi *gsi, u32 channel_id, bool start);

drivers/net/ipa/ipa_endpoint.c

@@ -1136,7 +1136,7 @@ static int ipa_endpoint_reset_rx_aggr(struct ipa_endpoint *endpoint)
 	bool endpoint_suspended = false;
 	struct gsi *gsi = &ipa->gsi;
 	dma_addr_t addr;
-	bool db_enable;
+	bool legacy;
 	u32 retries;
 	u32 len = 1;
 	void *virt;
@@ -1200,8 +1200,8 @@ static int ipa_endpoint_reset_rx_aggr(struct ipa_endpoint *endpoint)
 	 * complete the channel reset sequence.  Finish by suspending the
 	 * channel again (if necessary).
 	 */
-	db_enable = ipa->version == IPA_VERSION_3_5_1;
-	gsi_channel_reset(gsi, endpoint->channel_id, db_enable);
+	legacy = ipa->version == IPA_VERSION_3_5_1;
+	gsi_channel_reset(gsi, endpoint->channel_id, legacy);
 
 	msleep(1);
 
@@ -1223,8 +1223,8 @@ static void ipa_endpoint_reset(struct ipa_endpoint *endpoint)
 {
 	u32 channel_id = endpoint->channel_id;
 	struct ipa *ipa = endpoint->ipa;
-	bool db_enable;
 	bool special;
+	bool legacy;
 	int ret = 0;
 
 	/* On IPA v3.5.1, if an RX endpoint is reset while aggregation
@@ -1233,12 +1233,12 @@ static void ipa_endpoint_reset(struct ipa_endpoint *endpoint)
 	 *
 	 * IPA v3.5.1 enables the doorbell engine.  Newer versions do not.
 	 */
-	db_enable = ipa->version == IPA_VERSION_3_5_1;
+	legacy = ipa->version == IPA_VERSION_3_5_1;
 	special = !endpoint->toward_ipa && endpoint->data->aggregation;
 	if (special && ipa_endpoint_aggr_active(endpoint))
 		ret = ipa_endpoint_reset_rx_aggr(endpoint);
 	else
-		gsi_channel_reset(&ipa->gsi, channel_id, db_enable);
+		gsi_channel_reset(&ipa->gsi, channel_id, legacy);
 
 	if (ret)
 		dev_err(&ipa->pdev->dev,

drivers/net/ipa/ipa_main.c

@@ -108,7 +108,7 @@ int ipa_setup(struct ipa *ipa)
 	struct ipa_endpoint *command_endpoint;
 	int ret;
 
-	/* IPA v4.0 and above don't use the doorbell engine. */
+	/* Setup for IPA v3.5.1 has some slight differences */
 	ret = gsi_setup(&ipa->gsi, ipa->version == IPA_VERSION_3_5_1);
 	if (ret)
 		return ret;