Re: [PATCH v5 15/27] iommu/arm-smmu-v3: Add ssid to struct arm_smmu_master_domain

[Michael Shavit <mshavit@google.com>]

On Tue, Mar 5, 2024 at 7:44 AM Jason Gunthorpe <jgg@nvidia.com> wrote:
>
> Prepare to allow a S1 domain to be attached to a PASID as well. Keep track
> of the SSID the domain is using on each master in the
> arm_smmu_master_domain.
>
> Tested-by: Nicolin Chen <nicolinc@nvidia.com>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
>  .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   | 15 ++++---
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   | 42 +++++++++++++++----
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  5 ++-
>  3 files changed, 43 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
> index 9a285b828e8b12..ab9de8e36c45f5 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
> @@ -47,13 +47,12 @@ arm_smmu_update_s1_domain_cd_entry(struct arm_smmu_domain *smmu_domain)
>                 struct arm_smmu_master *master = master_domain->master;
>                 struct arm_smmu_cd *cdptr;
>
> -               /* S1 domains only support RID attachment right now */
> -               cdptr = arm_smmu_get_cd_ptr(master, IOMMU_NO_PASID);
> +               cdptr = arm_smmu_get_cd_ptr(master, master_domain->ssid);
>                 if (WARN_ON(!cdptr))
>                         continue;
>
>                 arm_smmu_make_s1_cd(&target_cd, master, smmu_domain);
> -               arm_smmu_write_cd_entry(master, IOMMU_NO_PASID, cdptr,
> +               arm_smmu_write_cd_entry(master, master_domain->ssid, cdptr,
>                                         &target_cd);
>         }
>         spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
> @@ -293,8 +292,8 @@ static void arm_smmu_mm_arch_invalidate_secondary_tlbs(struct mmu_notifier *mn,
>                                                     smmu_domain);
>         }
>
> -       arm_smmu_atc_inv_domain(smmu_domain, mm_get_enqcmd_pasid(mm), start,
> -                               size);
> +       arm_smmu_atc_inv_domain_sva(smmu_domain, mm_get_enqcmd_pasid(mm), start,
> +                                   size);
>  }
>
>  static void arm_smmu_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
> @@ -331,7 +330,7 @@ static void arm_smmu_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
>         spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
>
>         arm_smmu_tlb_inv_asid(smmu_domain->smmu, smmu_mn->cd->asid);
> -       arm_smmu_atc_inv_domain(smmu_domain, mm_get_enqcmd_pasid(mm), 0, 0);
> +       arm_smmu_atc_inv_domain_sva(smmu_domain, mm_get_enqcmd_pasid(mm), 0, 0);
>
>         smmu_mn->cleared = true;
>         mutex_unlock(&sva_lock);
> @@ -410,8 +409,8 @@ static void arm_smmu_mmu_notifier_put(struct arm_smmu_mmu_notifier *smmu_mn)
>          */
>         if (!smmu_mn->cleared) {
>                 arm_smmu_tlb_inv_asid(smmu_domain->smmu, cd->asid);
> -               arm_smmu_atc_inv_domain(smmu_domain, mm_get_enqcmd_pasid(mm), 0,
> -                                       0);
> +               arm_smmu_atc_inv_domain_sva(smmu_domain,
> +                                           mm_get_enqcmd_pasid(mm), 0, 0);
>         }
>
>         /* Frees smmu_mn */
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> index 45f2190fc31786..26c6b9f6f34fd3 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -2030,8 +2030,8 @@ static int arm_smmu_atc_inv_master(struct arm_smmu_master *master)
>         return arm_smmu_cmdq_batch_submit(master->smmu, &cmds);
>  }
>
> -int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,
> -                           unsigned long iova, size_t size)
> +static int __arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain,
> +                                    ioasid_t ssid, unsigned long iova, size_t size)
>  {
>         struct arm_smmu_master_domain *master_domain;
>         int i;
> @@ -2059,8 +2059,6 @@ int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,
>         if (!atomic_read(&smmu_domain->nr_ats_masters))
>                 return 0;
>
> -       arm_smmu_atc_inv_to_cmd(ssid, iova, size, &cmd);
> -
>         cmds.num = 0;
>
>         spin_lock_irqsave(&smmu_domain->devices_lock, flags);
> @@ -2071,6 +2069,16 @@ int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,
>                 if (!master->ats_enabled)
>                         continue;
>
> +               /*
> +                * Non-zero ssid means SVA is co-opting the S1 domain to issue
> +                * invalidations for SVA PASIDs.
> +                */
> +               if (ssid != IOMMU_NO_PASID)
> +                       arm_smmu_atc_inv_to_cmd(ssid, iova, size, &cmd);
> +               else
> +                       arm_smmu_atc_inv_to_cmd(master_domain->ssid, iova, size,
> +                                               &cmd);
> +
>                 for (i = 0; i < master->num_streams; i++) {
>                         cmd.atc.sid = master->streams[i].id;
>                         arm_smmu_cmdq_batch_add(smmu_domain->smmu, &cmds, &cmd);
> @@ -2081,6 +2089,19 @@ int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,
>         return arm_smmu_cmdq_batch_submit(smmu_domain->smmu, &cmds);
>  }
>
> +static int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain,
> +                                  unsigned long iova, size_t size)
> +{
> +       return __arm_smmu_atc_inv_domain(smmu_domain, IOMMU_NO_PASID, iova,
> +                                        size);
> +}
> +
> +int arm_smmu_atc_inv_domain_sva(struct arm_smmu_domain *smmu_domain,
> +                               ioasid_t ssid, unsigned long iova, size_t size)
> +{
> +       return __arm_smmu_atc_inv_domain(smmu_domain, ssid, iova, size);
> +}
> +
>  /* IO_PGTABLE API */
>  static void arm_smmu_tlb_inv_context(void *cookie)
>  {
> @@ -2102,7 +2123,7 @@ static void arm_smmu_tlb_inv_context(void *cookie)
>                 cmd.tlbi.vmid   = smmu_domain->s2_cfg.vmid;
>                 arm_smmu_cmdq_issue_cmd_with_sync(smmu, &cmd);
>         }
> -       arm_smmu_atc_inv_domain(smmu_domain, IOMMU_NO_PASID, 0, 0);
> +       arm_smmu_atc_inv_domain(smmu_domain, 0, 0);
>  }
>
>  static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd,
> @@ -2200,7 +2221,7 @@ static void arm_smmu_tlb_inv_range_domain(unsigned long iova, size_t size,
>          * Unfortunately, this can't be leaf-only since we may have
>          * zapped an entire table.
>          */
> -       arm_smmu_atc_inv_domain(smmu_domain, IOMMU_NO_PASID, iova, size);
> +       arm_smmu_atc_inv_domain(smmu_domain, iova, size);
>  }
>
>  void arm_smmu_tlb_inv_range_asid(unsigned long iova, size_t size, int asid,
> @@ -2539,7 +2560,8 @@ static void arm_smmu_disable_pasid(struct arm_smmu_master *master)
>
>  static struct arm_smmu_master_domain *
>  arm_smmu_find_master_domain(struct arm_smmu_domain *smmu_domain,
> -                           struct arm_smmu_master *master)
> +                           struct arm_smmu_master *master,
> +                           ioasid_t ssid)
>  {
>         struct arm_smmu_master_domain *master_domain;
>
> @@ -2547,7 +2569,8 @@ arm_smmu_find_master_domain(struct arm_smmu_domain *smmu_domain,
>
>         list_for_each_entry(master_domain, &smmu_domain->devices,
>                             devices_elm) {
> -               if (master_domain->master == master)
> +               if (master_domain->master == master &&
> +                   master_domain->ssid == ssid)
>                         return master_domain;
>         }
>         return NULL;
> @@ -2580,7 +2603,8 @@ static void arm_smmu_remove_master_domain(struct arm_smmu_master *master,
>                 return;
>
>         spin_lock_irqsave(&smmu_domain->devices_lock, flags);
> -       master_domain = arm_smmu_find_master_domain(smmu_domain, master);
> +       master_domain = arm_smmu_find_master_domain(smmu_domain, master,
> +                                                   IOMMU_NO_PASID);
>         if (master_domain) {
>                 list_del(&master_domain->devices_elm);
>                 kfree(master_domain);
> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> index c4b79bc52991be..98dc5885c48655 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> @@ -738,6 +738,7 @@ struct arm_smmu_domain {
>  struct arm_smmu_master_domain {
>         struct list_head devices_elm;
>         struct arm_smmu_master *master;
> +       u16 ssid;
>  };

SMMU_IDR1.SSIDSIZE may be up to 20 according to the spec. The value
read from this register is used to populate iommu.max_pasids as well
as to compute the smmu/master ssid_bits fields so u16 is insufficient
here.

>
>  static inline struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
> @@ -769,8 +770,8 @@ void arm_smmu_tlb_inv_range_asid(unsigned long iova, size_t size, int asid,
>                                  size_t granule, bool leaf,
>                                  struct arm_smmu_domain *smmu_domain);
>  bool arm_smmu_free_asid(struct arm_smmu_ctx_desc *cd);
> -int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,
> -                           unsigned long iova, size_t size);
> +int arm_smmu_atc_inv_domain_sva(struct arm_smmu_domain *smmu_domain,
> +                               ioasid_t ssid, unsigned long iova, size_t size);
>
>  #ifdef CONFIG_ARM_SMMU_V3_SVA
>  bool arm_smmu_sva_supported(struct arm_smmu_device *smmu);
> --
> 2.43.2
>

Apart from ssid size issue
Reviewed-by: Michael Shavit <mshavit@google.com>

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