[PATCH v5 07/27] iommu/arm-smmu-v3: Move the CD generation for S1 domains into a function

Michael Shavit mshavit at google.com
Wed Mar 13 05:13:12 PDT 2024


On Tue, Mar 5, 2024 at 7:44 AM Jason Gunthorpe <jgg at nvidia.com> wrote:
>
> Introduce arm_smmu_make_s1_cd() to build the CD from the paging S1 domain,
> and reorganize all the places programming S1 domain CD table entries to
> call it.
>
> Split arm_smmu_update_s1_domain_cd_entry() from
> arm_smmu_update_ctx_desc_devices() so that the S1 path has its own call
> chain separate from the unrelated SVA path.
>
> arm_smmu_update_s1_domain_cd_entry() only works on S1 domains
> attached to RIDs and refreshes all their CDs.
>
> Remove the forced clear of the CD during S1 domain attach,
> arm_smmu_write_cd_entry() will do this automatically if necessary.
>
> Tested-by: Nicolin Chen <nicolinc at nvidia.com>
> Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>
> ---
>  .../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c   | 25 +++++++-
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c   | 60 +++++++++++++------
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h   |  8 +++
>  3 files changed, 75 insertions(+), 18 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 bb9bb6fd7914ce..6acc65f6d00a71 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
> @@ -54,6 +54,29 @@ static void arm_smmu_update_ctx_desc_devices(struct arm_smmu_domain *smmu_domain
>         spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
>  }
>
> +static void
> +arm_smmu_update_s1_domain_cd_entry(struct arm_smmu_domain *smmu_domain)
> +{
> +       struct arm_smmu_master *master;
> +       struct arm_smmu_cd target_cd;
> +       unsigned long flags;
> +
> +       spin_lock_irqsave(&smmu_domain->devices_lock, flags);
> +       list_for_each_entry(master, &smmu_domain->devices, domain_head) {
> +               struct arm_smmu_cd *cdptr;
> +
> +               /* S1 domains only support RID attachment right now */
> +               cdptr = arm_smmu_get_cd_ptr(master, IOMMU_NO_PASID);
> +               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,
> +                                       &target_cd);
> +       }
> +       spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
> +}
> +
>  /*
>   * Check if the CPU ASID is available on the SMMU side. If a private context
>   * descriptor is using it, try to replace it.
> @@ -97,7 +120,7 @@ arm_smmu_share_asid(struct mm_struct *mm, u16 asid)
>          * be some overlap between use of both ASIDs, until we invalidate the
>          * TLB.
>          */
> -       arm_smmu_update_ctx_desc_devices(smmu_domain, IOMMU_NO_PASID, cd);
> +       arm_smmu_update_s1_domain_cd_entry(smmu_domain);

Not to be too nitpicky, but is calling this
arm_smmu_update_s1_domain_cd_entry the right choice here?  Yes the RID
domain has type "ARM_SMMU_DOMAIN_S1", but CDs are also stage 1
translations.

>
>         /* Invalidate TLB entries previously associated with that context */
>         arm_smmu_tlb_inv_asid(smmu, asid);
> 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 3fb4a1523d1d3f..e25dbb982feeee 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
> @@ -1222,8 +1222,8 @@ static void arm_smmu_write_cd_l1_desc(__le64 *dst,
>         WRITE_ONCE(*dst, cpu_to_le64(val));
>  }
>
> -static struct arm_smmu_cd *arm_smmu_get_cd_ptr(struct arm_smmu_master *master,
> -                                              u32 ssid)
> +struct arm_smmu_cd *arm_smmu_get_cd_ptr(struct arm_smmu_master *master,
> +                                       u32 ssid)
>  {
>         __le64 *l1ptr;
>         unsigned int idx;
> @@ -1288,9 +1288,9 @@ static const struct arm_smmu_entry_writer_ops arm_smmu_cd_writer_ops = {
>         .num_entry_qwords = sizeof(struct arm_smmu_cd) / sizeof(u64),
>  };
>
> -static void arm_smmu_write_cd_entry(struct arm_smmu_master *master, int ssid,
> -                                   struct arm_smmu_cd *cdptr,
> -                                   const struct arm_smmu_cd *target)
> +void arm_smmu_write_cd_entry(struct arm_smmu_master *master, int ssid,
> +                            struct arm_smmu_cd *cdptr,
> +                            const struct arm_smmu_cd *target)
>  {
>         struct arm_smmu_cd_writer cd_writer = {
>                 .writer = {
> @@ -1303,6 +1303,32 @@ static void arm_smmu_write_cd_entry(struct arm_smmu_master *master, int ssid,
>         arm_smmu_write_entry(&cd_writer.writer, cdptr->data, target->data);
>  }
>
> +void arm_smmu_make_s1_cd(struct arm_smmu_cd *target,
> +                        struct arm_smmu_master *master,
> +                        struct arm_smmu_domain *smmu_domain)
> +{
> +       struct arm_smmu_ctx_desc *cd = &smmu_domain->cd;
> +
> +       memset(target, 0, sizeof(*target));
> +
> +       target->data[0] = cpu_to_le64(
> +               cd->tcr |
> +#ifdef __BIG_ENDIAN
> +               CTXDESC_CD_0_ENDI |
> +#endif
> +               CTXDESC_CD_0_V |
> +               CTXDESC_CD_0_AA64 |
> +               (master->stall_enabled ? CTXDESC_CD_0_S : 0) |
> +               CTXDESC_CD_0_R |
> +               CTXDESC_CD_0_A |
> +               CTXDESC_CD_0_ASET |
> +               FIELD_PREP(CTXDESC_CD_0_ASID, cd->asid)
> +               );
> +
> +       target->data[1] = cpu_to_le64(cd->ttbr & CTXDESC_CD_1_TTB0_MASK);
> +       target->data[3] = cpu_to_le64(cd->mair);
> +}
> +
>  void arm_smmu_clear_cd(struct arm_smmu_master *master, ioasid_t ssid)
>  {
>         struct arm_smmu_cd target = {};
> @@ -2689,29 +2715,29 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
>         spin_unlock_irqrestore(&smmu_domain->devices_lock, flags);
>
>         switch (smmu_domain->stage) {
> -       case ARM_SMMU_DOMAIN_S1:
> +       case ARM_SMMU_DOMAIN_S1: {
> +               struct arm_smmu_cd target_cd;
> +               struct arm_smmu_cd *cdptr;
> +
>                 if (!master->cd_table.cdtab) {
>                         ret = arm_smmu_alloc_cd_tables(master);
>                         if (ret)
>                                 goto out_list_del;
> -               } else {
> -                       /*
> -                        * arm_smmu_write_ctx_desc() relies on the entry being
> -                        * invalid to work, clear any existing entry.
> -                        */
> -                       ret = arm_smmu_write_ctx_desc(master, IOMMU_NO_PASID,
> -                                                     NULL);
> -                       if (ret)
> -                               goto out_list_del;
>                 }
>
> -               ret = arm_smmu_write_ctx_desc(master, IOMMU_NO_PASID, &smmu_domain->cd);
> -               if (ret)
> +               cdptr = arm_smmu_get_cd_ptr(master, IOMMU_NO_PASID);
> +               if (!cdptr) {
> +                       ret = -ENOMEM;
>                         goto out_list_del;
> +               }
>
> +               arm_smmu_make_s1_cd(&target_cd, master, smmu_domain);
> +               arm_smmu_write_cd_entry(master, IOMMU_NO_PASID, cdptr,
> +                                       &target_cd);
>                 arm_smmu_make_cdtable_ste(&target, master);
>                 arm_smmu_install_ste_for_dev(master, &target);
>                 break;
> +       }
>         case ARM_SMMU_DOMAIN_S2:
>                 arm_smmu_make_s2_domain_ste(&target, master, smmu_domain);
>                 arm_smmu_install_ste_for_dev(master, &target);
> 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 87a7b57f566fbc..d32da11058aab6 100644
> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
> @@ -750,6 +750,14 @@ extern struct mutex arm_smmu_asid_lock;
>  extern struct arm_smmu_ctx_desc quiet_cd;
>
>  void arm_smmu_clear_cd(struct arm_smmu_master *master, ioasid_t ssid);
> +struct arm_smmu_cd *arm_smmu_get_cd_ptr(struct arm_smmu_master *master,
> +                                       u32 ssid);
> +void arm_smmu_make_s1_cd(struct arm_smmu_cd *target,
> +                        struct arm_smmu_master *master,
> +                        struct arm_smmu_domain *smmu_domain);
> +void arm_smmu_write_cd_entry(struct arm_smmu_master *master, int ssid,
> +                            struct arm_smmu_cd *cdptr,
> +                            const struct arm_smmu_cd *target);
>
>  int arm_smmu_write_ctx_desc(struct arm_smmu_master *smmu_master, int ssid,
>                             struct arm_smmu_ctx_desc *cd);
> --
> 2.43.2
>
Reviewed-by: Michael Shavit <mshavit at google.com>



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