[PATCH net-next 0/4] net: dsa: Allow switch drivers to indicate number of TX queues

[PATCH net-next 0/4] net: dsa: Allow switch drivers to indicate number of TX queues

[Florian Fainelli]

Hi all,

This patch series extracts the parts of the patch set that are likely not to be
controversial and actually bringing multi-queue support to DSA-created network
devices.

With these patches, we can now use sch_multiq as documented under
Documentation/networking/multique.txt and let applications dedice the switch
port output queue they want to use. Currently only Broadcom tags utilize that
information.

Changes from RFC:

- dropped the ability to configure RX queues since we don't do anything with
  those just yet
- dropped the patches that dealt with binding the DSA slave network devices
  queues with their master network devices queues this will be worked on
  separately.

Florian Fainelli (4):
  net: dsa: Allow switch drivers to indicate number of TX queues
  net: dsa: tag_brcm: Set output queue from skb queue mapping
  net: dsa: bcm_sf2: Advertise number of egress queues
  net: dsa: bcm_sf2: Configure IMP port TC2QOS mapping

 drivers/net/dsa/bcm_sf2.c | 12 ++++++++++++
 include/net/dsa.h         |  3 +++
 net/dsa/slave.c           |  8 ++++++--
 net/dsa/tag_brcm.c        |  3 ++-
 4 files changed, 23 insertions(+), 3 deletions(-)

-- 
1.9.1

[PATCH net-next 1/4] net: dsa: Allow switch drivers to indicate number of TX queues

[Florian Fainelli]

Let switch drivers indicate how many TX queues they support. Some
switches, such as Broadcom Starfighter 2 are designed with 8 egress
queues. Future changes will allow us to leverage the queue mapping and
direct the transmission towards a particular queue.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 include/net/dsa.h | 3 +++
 net/dsa/slave.c   | 8 ++++++--
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/include/net/dsa.h b/include/net/dsa.h
index 398ca8d70ccd..dd44d6ce1097 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -243,6 +243,9 @@ struct dsa_switch {
 	/* devlink used to represent this switch device */
 	struct devlink		*devlink;
 
+	/* Number of switch port queues */
+	unsigned int		num_tx_queues;
+
 	/* Dynamically allocated ports, keep last */
 	size_t num_ports;
 	struct dsa_port ports[];
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 78e78a6e6833..2afa99506f8b 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -1259,8 +1259,12 @@ int dsa_slave_create(struct dsa_port *port, const char *name)
 	cpu_dp = ds->dst->cpu_dp;
 	master = cpu_dp->netdev;
 
-	slave_dev = alloc_netdev(sizeof(struct dsa_slave_priv), name,
-				 NET_NAME_UNKNOWN, ether_setup);
+	if (!ds->num_tx_queues)
+		ds->num_tx_queues = 1;
+
+	slave_dev = alloc_netdev_mqs(sizeof(struct dsa_slave_priv), name,
+				     NET_NAME_UNKNOWN, ether_setup,
+				     ds->num_tx_queues, 1);
 	if (slave_dev == NULL)
 		return -ENOMEM;
 
-- 
1.9.1

[PATCH net-next 2/4] net: dsa: tag_brcm: Set output queue from skb queue mapping

[Florian Fainelli]

We originally used skb->priority but that was not quite correct as this
bitfield needs to contain the egress switch queue we intend to send this
SKB to.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 net/dsa/tag_brcm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/dsa/tag_brcm.c b/net/dsa/tag_brcm.c
index de74c3f77818..dbb016434ace 100644
--- a/net/dsa/tag_brcm.c
+++ b/net/dsa/tag_brcm.c
@@ -62,6 +62,7 @@
 static struct sk_buff *brcm_tag_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct dsa_slave_priv *p = netdev_priv(dev);
+	u16 queue = skb_get_queue_mapping(skb);
 	u8 *brcm_tag;
 
 	if (skb_cow_head(skb, BRCM_TAG_LEN) < 0)
@@ -78,7 +79,7 @@ static struct sk_buff *brcm_tag_xmit(struct sk_buff *skb, struct net_device *dev
 	 * deprecated
 	 */
 	brcm_tag[0] = (1 << BRCM_OPCODE_SHIFT) |
-			((skb->priority << BRCM_IG_TC_SHIFT) & BRCM_IG_TC_MASK);
+		       ((queue & BRCM_IG_TC_MASK) << BRCM_IG_TC_SHIFT);
 	brcm_tag[1] = 0;
 	brcm_tag[2] = 0;
 	if (p->dp->index == 8)
-- 
1.9.1

[PATCH net-next 3/4] net: dsa: bcm_sf2: Advertise number of egress queues

[Florian Fainelli]

The switch supports 8 egress queues per port, so indicate that such that
net/dsa/slave.c::dsa_slave_create can allocate the right number of TX
queues.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/dsa/bcm_sf2.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/dsa/bcm_sf2.c b/drivers/net/dsa/bcm_sf2.c
index 8492c9d64004..3f1ad9d5d7c5 100644
--- a/drivers/net/dsa/bcm_sf2.c
+++ b/drivers/net/dsa/bcm_sf2.c
@@ -1147,6 +1147,9 @@ static int bcm_sf2_sw_probe(struct platform_device *pdev)
 	ds = dev->ds;
 	ds->ops = &bcm_sf2_ops;
 
+	/* Advertise the 8 egress queues */
+	ds->num_tx_queues = 8;
+
 	dev_set_drvdata(&pdev->dev, priv);
 
 	spin_lock_init(&priv->indir_lock);
-- 
1.9.1

[PATCH net-next 4/4] net: dsa: bcm_sf2: Configure IMP port TC2QOS mapping

[Florian Fainelli]

Even though TC2QOS mapping is for switch egress queues, we need to
configure it correclty in order for the Broadcom tag ingress (CPU ->
switch) queue selection to work correctly since there is a 1:1 mapping
between switch egress queues and ingress queues.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/dsa/bcm_sf2.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/net/dsa/bcm_sf2.c b/drivers/net/dsa/bcm_sf2.c
index 3f1ad9d5d7c5..fc9f9f171e55 100644
--- a/drivers/net/dsa/bcm_sf2.c
+++ b/drivers/net/dsa/bcm_sf2.c
@@ -103,6 +103,7 @@ static void bcm_sf2_brcm_hdr_setup(struct bcm_sf2_priv *priv, int port)
 static void bcm_sf2_imp_setup(struct dsa_switch *ds, int port)
 {
 	struct bcm_sf2_priv *priv = bcm_sf2_to_priv(ds);
+	unsigned int i;
 	u32 reg, offset;
 
 	if (priv->type == BCM7445_DEVICE_ID)
@@ -129,6 +130,14 @@ static void bcm_sf2_imp_setup(struct dsa_switch *ds, int port)
 	reg |= MII_DUMB_FWDG_EN;
 	core_writel(priv, reg, CORE_SWITCH_CTRL);
 
+	/* Configure Traffic Class to QoS mapping, allow each priority to map
+	 * to a different queue number
+	 */
+	reg = core_readl(priv, CORE_PORT_TC2_QOS_MAP_PORT(port));
+	for (i = 0; i < 8; i++)
+		reg |= i << (PRT_TO_QID_SHIFT * i);
+	core_writel(priv, reg, CORE_PORT_TC2_QOS_MAP_PORT(port));
+
 	bcm_sf2_brcm_hdr_setup(priv, port);
 
 	/* Force link status for IMP port */
-- 
1.9.1

Re: [PATCH net-next 4/4] net: dsa: bcm_sf2: Configure IMP port TC2QOS mapping

[Andrew Lunn]

> @@ -129,6 +130,14 @@ static void bcm_sf2_imp_setup(struct dsa_switch *ds, int port)
>  	reg |= MII_DUMB_FWDG_EN;
>  	core_writel(priv, reg, CORE_SWITCH_CTRL);
>  
> +	/* Configure Traffic Class to QoS mapping, allow each priority to map
> +	 * to a different queue number
> +	 */
> +	reg = core_readl(priv, CORE_PORT_TC2_QOS_MAP_PORT(port));
> +	for (i = 0; i < 8; i++)
> +		reg |= i << (PRT_TO_QID_SHIFT * i);

Hi Florian

Rather than 8, would ds->num_tx_queues be more descriptive?

       Andrew

Re: [PATCH net-next 4/4] net: dsa: bcm_sf2: Configure IMP port TC2QOS mapping

[Florian Fainelli]

On 09/02/2017 09:30 AM, Andrew Lunn wrote:
>> @@ -129,6 +130,14 @@ static void bcm_sf2_imp_setup(struct dsa_switch *ds, int port)
>>  	reg |= MII_DUMB_FWDG_EN;
>>  	core_writel(priv, reg, CORE_SWITCH_CTRL);
>>  
>> +	/* Configure Traffic Class to QoS mapping, allow each priority to map
>> +	 * to a different queue number
>> +	 */
>> +	reg = core_readl(priv, CORE_PORT_TC2_QOS_MAP_PORT(port));
>> +	for (i = 0; i < 8; i++)
>> +		reg |= i << (PRT_TO_QID_SHIFT * i);
> 
> Hi Florian
> 
> Rather than 8, would ds->num_tx_queues be more descriptive?

I actually have a patch on top of this which defines a constant for the
number of queues instead of open coding 8 here. Thanks!
-- 
Florian

Re: [PATCH net-next 4/4] net: dsa: bcm_sf2: Configure IMP port TC2QOS mapping

[Andrew Lunn]

On Sat, Sep 02, 2017 at 09:32:08AM -0700, Florian Fainelli wrote:
> 
> 
> On 09/02/2017 09:30 AM, Andrew Lunn wrote:
> >> @@ -129,6 +130,14 @@ static void bcm_sf2_imp_setup(struct dsa_switch *ds, int port)
> >>  	reg |= MII_DUMB_FWDG_EN;
> >>  	core_writel(priv, reg, CORE_SWITCH_CTRL);
> >>  
> >> +	/* Configure Traffic Class to QoS mapping, allow each priority to map
> >> +	 * to a different queue number
> >> +	 */
> >> +	reg = core_readl(priv, CORE_PORT_TC2_QOS_MAP_PORT(port));
> >> +	for (i = 0; i < 8; i++)
> >> +		reg |= i << (PRT_TO_QID_SHIFT * i);
> > 
> > Hi Florian
> > 
> > Rather than 8, would ds->num_tx_queues be more descriptive?
> 
> I actually have a patch on top of this which defines a constant for the
> number of queues instead of open coding 8 here. Thanks!

Hi Florian

It sounds like it should be part of 3/4?

   Andrew

Re: [PATCH net-next 4/4] net: dsa: bcm_sf2: Configure IMP port TC2QOS mapping

[Florian Fainelli]

On 09/02/2017 10:47 AM, Andrew Lunn wrote:
> On Sat, Sep 02, 2017 at 09:32:08AM -0700, Florian Fainelli wrote:
>>
>>
>> On 09/02/2017 09:30 AM, Andrew Lunn wrote:
>>>> @@ -129,6 +130,14 @@ static void bcm_sf2_imp_setup(struct dsa_switch *ds, int port)
>>>>  	reg |= MII_DUMB_FWDG_EN;
>>>>  	core_writel(priv, reg, CORE_SWITCH_CTRL);
>>>>  
>>>> +	/* Configure Traffic Class to QoS mapping, allow each priority to map
>>>> +	 * to a different queue number
>>>> +	 */
>>>> +	reg = core_readl(priv, CORE_PORT_TC2_QOS_MAP_PORT(port));
>>>> +	for (i = 0; i < 8; i++)
>>>> +		reg |= i << (PRT_TO_QID_SHIFT * i);
>>>
>>> Hi Florian
>>>
>>> Rather than 8, would ds->num_tx_queues be more descriptive?
>>
>> I actually have a patch on top of this which defines a constant for the
>> number of queues instead of open coding 8 here. Thanks!
> 
> Hi Florian
> 
> It sounds like it should be part of 3/4?

Right, let me re-submit with that change included. Thanks
-- 
Florian