[dpdk-dev] [PATCH 05/10] linuxapp/eal: detect iova mode

[santosh]

Hi Hemant,

On Wednesday 05 July 2017 06:47 PM, Hemant Agrawal wrote:

> On 6/8/2017 4:35 PM, Santosh Shukla wrote:
>> - Moving late bus scanning to up..just after eal_parsing.
>> - Detect iova mapping mode based on user provided eal option
>>   (rte_eal_iova_mode) and result of rte_bus_scan_iommu_class.
>>
>> Signed-off-by: Santosh Shukla <santosh.shukla at caviumnetworks.com>
>> Signed-off-by: Jerin Jacob <jerin.jacob at caviumnetworks.com>
>> ---
>>  lib/librte_eal/linuxapp/eal/eal.c               | 24 ++++++++++++++++++------
>>  lib/librte_eal/linuxapp/eal/rte_eal_version.map |  1 +
>>  2 files changed, 19 insertions(+), 6 deletions(-)
>>
>> diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c
>> index 7c78f2dc2..54f42d752 100644
>> --- a/lib/librte_eal/linuxapp/eal/eal.c
>> +++ b/lib/librte_eal/linuxapp/eal/eal.c
>> @@ -122,6 +122,13 @@ struct internal_config internal_config;
>>  /* used by rte_rdtsc() */
>>  int rte_cycles_vmware_tsc_map;
>>
>> +/* Get the iova mode */
>> +enum rte_iova_mode
>> +rte_eal_iova_mode(void)
>> +{
>> +    return internal_config.iova_mode;
>> +}
>> +
>>  /* Return a pointer to the configuration structure */
>>  struct rte_config *
>>  rte_eal_get_configuration(void)
>> @@ -793,6 +800,17 @@ rte_eal_init(int argc, char **argv)
>>          return -1;
>>      }
>>
>> +    if (rte_bus_scan()) {
>> +        rte_eal_init_alert("Cannot scan the buses for devices\n");
>> +        rte_errno = ENODEV;
>> +        return -1;
>> +    }
>> +
>
> The bus scanning includes allocating memory for the devices. It can not be moved so early.
>
Right and that memory allocation is malloc based. I verified for same for pci_scan_one case.
Also looking at drivers/bus/fslmc/* , IIUC then your not calling rte_mem* api's at the time of
bus scanning, right? And you do dma_mapping at ethdev initialization time which is referring
to memseg, so afaict, prepositioning bus_scan at very early won't effect functionality.
 

> I am still testing it out.

Thanks for testing, Please share you feedback.