Re: [PATCH v3 24/25] iommu/dma: Factor out flush queue init

[Rajat Jain <rajatja@google.com>]

On Wed, Aug 4, 2021 at 10:16 AM Robin Murphy <robin.murphy@arm.com> wrote:
>
> Factor out flush queue setup from the initial domain init so that we
> can potentially trigger it from sysfs later on in a domain's lifetime.
>
> Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
> Reviewed-by: John Garry <john.garry@huawei.com>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
>  drivers/iommu/dma-iommu.c | 30 ++++++++++++++++++++----------
>  include/linux/dma-iommu.h |  9 ++++++---
>  2 files changed, 26 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index 2e19505dddf9..f51b8dc99ac6 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -310,6 +310,25 @@ static bool dev_is_untrusted(struct device *dev)
>         return dev_is_pci(dev) && to_pci_dev(dev)->untrusted;
>  }
>
> +int iommu_dma_init_fq(struct iommu_domain *domain)
> +{
> +       struct iommu_dma_cookie *cookie = domain->iova_cookie;
> +
> +       if (domain->type != IOMMU_DOMAIN_DMA_FQ)
> +               return -EINVAL;
> +       if (cookie->fq_domain)
> +               return 0;
> +
> +       if (init_iova_flush_queue(&cookie->iovad, iommu_dma_flush_iotlb_all,
> +                                 iommu_dma_entry_dtor)) {
> +               pr_warn("iova flush queue initialization failed\n");
> +               domain->type = IOMMU_DOMAIN_DMA;
> +               return -ENODEV;
> +       }
> +       cookie->fq_domain = domain;
> +       return 0;
> +}
> +
>  /**
>   * iommu_dma_init_domain - Initialise a DMA mapping domain
>   * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()
> @@ -362,16 +381,7 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
>         }
>
>         init_iova_domain(iovad, 1UL << order, base_pfn);
> -
> -       if (domain->type == IOMMU_DOMAIN_DMA_FQ && !cookie->fq_domain) {
> -               if (init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all,
> -                                         iommu_dma_entry_dtor)) {
> -                       pr_warn("iova flush queue initialization failed\n");
> -                       domain->type = IOMMU_DOMAIN_DMA;
> -               } else {
> -                       cookie->fq_domain = domain;
> -               }
> -       }
> +       iommu_dma_init_fq(domain);
>
>         return iova_reserve_iommu_regions(dev, domain);
>  }
> diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
> index 758ca4694257..81ab647f1618 100644
> --- a/include/linux/dma-iommu.h
> +++ b/include/linux/dma-iommu.h
> @@ -20,6 +20,7 @@ void iommu_put_dma_cookie(struct iommu_domain *domain);
>
>  /* Setup call for arch DMA mapping code */
>  void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 dma_limit);
> +int iommu_dma_init_fq(struct iommu_domain *domain);
>
>  /* The DMA API isn't _quite_ the whole story, though... */
>  /*
> @@ -37,9 +38,6 @@ void iommu_dma_compose_msi_msg(struct msi_desc *desc,
>
>  void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
>
> -void iommu_dma_free_cpu_cached_iovas(unsigned int cpu,
> -               struct iommu_domain *domain);
> -

This looks like an unrelated code cleanup. Should this be a separate patch?

Thanks,

Rajat


>  extern bool iommu_dma_forcedac;
>
>  #else /* CONFIG_IOMMU_DMA */
> @@ -54,6 +52,11 @@ static inline void iommu_setup_dma_ops(struct device *dev, u64 dma_base,
>  {
>  }
>
> +static inline int iommu_dma_init_fq(struct iommu_domain *domain)
> +{
> +       return -EINVAL;
> +}
> +
>  static inline int iommu_get_dma_cookie(struct iommu_domain *domain)
>  {
>         return -ENODEV;
> --
> 2.25.1
>