[dpdk-dev] [PATCH v3 1/3] eal: add API for bus close

[Ferruh Yigit]

On 9/30/2020 12:50 PM, Ferruh Yigit wrote:
> On 8/26/2020 6:52 AM, rohit.raj at nxp.com wrote:
>> From: Rohit Raj <rohit.raj at nxp.com>
>>
>> As per the current code we have API for bus probe, but the
>> bus close API is missing. This breaks the multi process
>> scenarios as objects are not cleaned while terminating the
>> secondary processes.
>>
>> This patch adds a new API rte_bus_close() for cleanup of
>> bus objects which were acquired during probe.
>>
>> Signed-off-by: Rohit Raj <rohit.raj at nxp.com>
>> ---
>>
>> v3:
>> * nit: combined nested if statements
>>
>> v2:
>> * Moved rte_bus_close call to rte_eal_cleanup path.
>>
>>   lib/librte_eal/common/eal_common_bus.c | 32 +++++++++++++++++++++++++-
>>   lib/librte_eal/include/rte_bus.h       | 25 +++++++++++++++++++-
>>   lib/librte_eal/linux/eal.c             |  1 +
>>   lib/librte_eal/rte_eal_version.map     |  3 +++
>>   4 files changed, 59 insertions(+), 2 deletions(-)
>>
>> diff --git a/lib/librte_eal/common/eal_common_bus.c 
>> b/lib/librte_eal/common/eal_common_bus.c
>> index baa5b532a..5fd7cf6c5 100644
>> --- a/lib/librte_eal/common/eal_common_bus.c
>> +++ b/lib/librte_eal/common/eal_common_bus.c
>> @@ -1,5 +1,5 @@
>>   /* SPDX-License-Identifier: BSD-3-Clause
>> - * Copyright 2016 NXP
>> + * Copyright 2016,2020 NXP
>>    */
>>   #include <stdio.h>
>> @@ -56,6 +56,36 @@ rte_bus_scan(void)
>>       return 0;
>>   }
>> +int
>> +rte_bus_close(void)
>> +{
>> +    int ret;
>> +    struct rte_bus *bus, *vbus = NULL;
>> +
>> +    TAILQ_FOREACH(bus, &rte_bus_list, next) {
>> +        if (!strcmp(bus->name, "vdev")) {
>> +            vbus = bus;
>> +            continue;
>> +        }
> 
> This special treatment for 'vdev' bus is done in probe to be sure physically 
> device port ids start from '0',  I guess we don't need to do this for 'close'.
> 
>> +
>> +        if (bus->close) {
>> +            ret = bus->close();
>> +            if (ret)
>> +                RTE_LOG(ERR, EAL, "Bus (%s) close failed.\n",
>> +                    bus->name);
>> +        }
>> +    }
>> +
>> +    if (vbus && vbus->close) {
>> +        ret = vbus->close();
>> +        if (ret)
>> +            RTE_LOG(ERR, EAL, "Bus (%s) close failed.\n",
>> +                vbus->name);
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>>   /* Probe all devices of all buses */
>>   int
>>   rte_bus_probe(void)
>> diff --git a/lib/librte_eal/include/rte_bus.h b/lib/librte_eal/include/rte_bus.h
>> index d3034d0ed..af4787b18 100644
>> --- a/lib/librte_eal/include/rte_bus.h
>> +++ b/lib/librte_eal/include/rte_bus.h
>> @@ -1,5 +1,5 @@
>>   /* SPDX-License-Identifier: BSD-3-Clause
>> - * Copyright 2016 NXP
>> + * Copyright 2016,2020 NXP
>>    */
>>   #ifndef _RTE_BUS_H_
>> @@ -67,6 +67,18 @@ typedef int (*rte_bus_scan_t)(void);
>>    */
>>   typedef int (*rte_bus_probe_t)(void);
>> +/**
>> + * Implementation specific close function which is responsible for closing
>> + * devices on that bus.
>> + *
>> + * This is called while iterating over each registered bus.
>> + *
>> + * @return
>> + *    0 for successful close
>> + *    !0 for any error while closing
>> + */
>> +typedef int (*rte_bus_close_t)(void);
>> +
> 
> As I checked the 'rte_fslmc_bus->close()' ops, it iterates on all devices in the 
> bus instead of doing a bus level close, in that case
> instead of adding a new 'close' bus operations, will it work if existing 
> 'bus->unplug(dev)' used?
> Whatever done in the 'rte_fslmc_bus->close()' per device, can it be done under 
> the 'fslmc_bus_unplug()'?
> 
> And in that case a 'rte_bus_remove()' API can be added which can call 
> 'bus->unplug(dev)' for all buses and it will be beneficial for all buses, and it 
> can fit well into the 'rte_eal_cleanup()'.
> 
> What do you think?

Hi Rohit,

I have seen new version has been sent today, I want to remind above question, 
can you please check it?