On Sat Aug 22 2020, Vladimir Oltean wrote:
> Hi Kurt,
>
> On Thu, Aug 20, 2020 at 10:11:15AM +0200, Kurt Kanzenbach wrote:
>> The switch has support for the 802.1Qbv Time Aware Shaper (TAS). Traffic
>> schedules may be configured individually on each front port. Each port has eight
>> egress queues. The traffic is mapped to a traffic class respectively via the PCP
>> field of a VLAN tagged frame.
>>
>> The TAPRIO Qdisc already implements that. Therefore, this interface can simply
>> be reused. Add .port_setup_tc() accordingly.
>>
>> The activation of a schedule on a port is split into two parts:
>>
>> * Programming the necessary gate control list (GCL)
>> * Setup hrtimer for starting the schedule
>>
>> The hardware supports starting a schedule up to eight seconds in the future. The
>> TAPRIO interface provides an absolute base time. Therefore, hrtimers are
>> leveraged.
>>
>> Signed-off-by: Kurt Kanzenbach <kurt@xxxxxxxxxxxxx>
>> ---
>> drivers/net/dsa/hirschmann/hellcreek.c | 294 +++++++++++++++++++++++++
>> drivers/net/dsa/hirschmann/hellcreek.h | 21 ++
>> 2 files changed, 315 insertions(+)
>>
>> diff --git a/drivers/net/dsa/hirschmann/hellcreek.c b/drivers/net/dsa/hirschmann/hellcreek.c
>> index 745ca60342b4..e5b54f42c635 100644
>> --- a/drivers/net/dsa/hirschmann/hellcreek.c
>> +++ b/drivers/net/dsa/hirschmann/hellcreek.c
>> @@ -22,7 +22,9 @@
>> #include <linux/spinlock.h>
>> #include <linux/delay.h>
>> #include <linux/ktime.h>
>> +#include <linux/time.h>
>> #include <net/dsa.h>
>> +#include <net/pkt_sched.h>
>>
>> #include "hellcreek.h"
>> #include "hellcreek_ptp.h"
>> @@ -153,6 +155,15 @@ static void hellcreek_select_vlan(struct hellcreek *hellcreek, int vid,
>> hellcreek_write(hellcreek, val, HR_VIDCFG);
>> }
>>
>> +static void hellcreek_select_tgd(struct hellcreek *hellcreek, int port)
>> +{
>> + u16 val = 0;
>> +
>> + val |= port << TR_TGDSEL_TDGSEL_SHIFT;
>> +
>> + hellcreek_write(hellcreek, val, TR_TGDSEL);
>> +}
>> +
>> static int hellcreek_wait_until_ready(struct hellcreek *hellcreek)
>> {
>> u16 val;
>> @@ -958,6 +969,24 @@ static void __hellcreek_setup_tc_identity_mapping(struct hellcreek *hellcreek)
>> }
>> }
>>
>> +static void hellcreek_setup_tc_mapping(struct hellcreek *hellcreek,
>> + struct net_device *netdev)
>> +{
>> + int i, j;
>> +
>> + /* Setup mapping between traffic classes and port queues. */
>> + for (i = 0; i < netdev_get_num_tc(netdev); ++i) {
>> + for (j = 0; j < netdev->tc_to_txq[i].count; ++j) {
>> + const int queue = j + netdev->tc_to_txq[i].offset;
>> +
>> + hellcreek_select_prio(hellcreek, i);
>> + hellcreek_write(hellcreek,
>> + queue << HR_PRTCCFG_PCP_TC_MAP_SHIFT,
>> + HR_PRTCCFG);
>> + }
>> + }
>> +}
>
> What other driver have you seen that does this?
>
Probably none.
With TAPRIO traffic classes and the mapping to queues can be
configured. The switch can also map traffic classes. That sounded like a
good match to me.
Thanks,
Kurt
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