Re: [dpdk-dev] [PATCH v2 1/5] bus/fslmc: fix physical addressing check

[Pavan Nikhilesh <pbhagavatula@caviumnetworks.com>]

Hi Shreyansh,

On Tue, Oct 09, 2018 at 04:55:44PM +0530, Shreyansh Jain wrote:
> In case RTE_LIBRTE_DPAA2_USE_PHYS_IOVA is enabled, only supported
> class is RTE_IOVA_PA.
>
> Fixes: f7768afac101 ("bus/fslmc: support dynamic IOVA")
> Cc: hemant.agrawal@nxp.com
>
> Signed-off-by: Shreyansh Jain <shreyansh.jain@nxp.com>
> ---
>  drivers/bus/fslmc/fslmc_bus.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/drivers/bus/fslmc/fslmc_bus.c b/drivers/bus/fslmc/fslmc_bus.c
> index bfe81e236..a4f9a9eee 100644
> --- a/drivers/bus/fslmc/fslmc_bus.c
> +++ b/drivers/bus/fslmc/fslmc_bus.c
> @@ -491,6 +491,10 @@ rte_dpaa2_get_iommu_class(void)
>         bool is_vfio_noiommu_enabled = 1;
>         bool has_iova_va;
>
> +#ifdef RTE_LIBRTE_DPAA2_USE_PHYS_IOVA
> +       return RTE_IOVA_PA;
> +#endif
> +

As, RTE_LIBRTE_DPAA2_USE_PHYS_IOVA is set to true by default[1] and fslmc bus
being always registered[2] irrespective of the underlying platform, the IOVA class
will be always returned as PA.
This will break multiple platforms as some work only when IOVA as VA. I think
you need to verify if the underlying platform is really FLMC similar to DPAA[3]

[1]
->[master]ltp-pvn[dpdk] $ grep -nir "RTE_LIBRTE_DPAA2_USE_PHYS_IOVA" config/
config/meson.build:86:dpdk_conf.set('RTE_LIBRTE_DPAA2_USE_PHYS_IOVA', true)
config/common_base:218:CONFIG_RTE_LIBRTE_DPAA2_USE_PHYS_IOVA=y

[2]
config/common_linuxapp:45:CONFIG_RTE_LIBRTE_FSLMC_BUS=y

[3]
	static enum rte_iova_mode
	rte_dpaa_get_iommu_class(void)
	{
		if ((access(DPAA_DEV_PATH1, F_OK) != 0) &&
				(access(DPAA_DEV_PATH2, F_OK) != 0)) {
			return RTE_IOVA_DC;
		}
		return RTE_IOVA_PA;
	}


>         if (TAILQ_EMPTY(&rte_fslmc_bus.device_list))
>                 return RTE_IOVA_DC;
>
> --
> 2.17.1
>

Thanks,
Pavan.