On 16.05.2023 02:00, Jason Gunthorpe wrote:
> What exynos calls exynos_iommu_detach_device is actually putting the iommu
> into identity mode.
>
> Move to the new core support for ARM_DMA_USE_IOMMU by defining
> ops->identity_domain.
>
> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Acked-by: Marek Szyprowski
> ---
> drivers/iommu/exynos-iommu.c | 66 +++++++++++++++++-------------------
> 1 file changed, 32 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
> index c275fe71c4db32..5e12b85dfe8705 100644
> --- a/drivers/iommu/exynos-iommu.c
> +++ b/drivers/iommu/exynos-iommu.c
> @@ -24,6 +24,7 @@
>
> typedef u32 sysmmu_iova_t;
> typedef u32 sysmmu_pte_t;
> +static struct iommu_domain exynos_identity_domain;
>
> /* We do not consider super section mapping (16MB) */
> #define SECT_ORDER 20
> @@ -829,7 +830,7 @@ static int __maybe_unused exynos_sysmmu_suspend(struct device *dev)
> struct exynos_iommu_owner *owner = dev_iommu_priv_get(master);
>
> mutex_lock(&owner->rpm_lock);
> - if (data->domain) {
> + if (&data->domain->domain != &exynos_identity_domain) {
> dev_dbg(data->sysmmu, "saving state\n");
> __sysmmu_disable(data);
> }
> @@ -847,7 +848,7 @@ static int __maybe_unused exynos_sysmmu_resume(struct device *dev)
> struct exynos_iommu_owner *owner = dev_iommu_priv_get(master);
>
> mutex_lock(&owner->rpm_lock);
> - if (data->domain) {
> + if (&data->domain->domain != &exynos_identity_domain) {
> dev_dbg(data->sysmmu, "restoring state\n");
> __sysmmu_enable(data);
> }
> @@ -980,17 +981,20 @@ static void exynos_iommu_domain_free(struct iommu_domain *iommu_domain)
> kfree(domain);
> }
>
> -static void exynos_iommu_detach_device(struct iommu_domain *iommu_domain,
> - struct device *dev)
> +static int exynos_iommu_identity_attach(struct iommu_domain *identity_domain,
> + struct device *dev)
> {
> - struct exynos_iommu_domain *domain = to_exynos_domain(iommu_domain);
> struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
> - phys_addr_t pagetable = virt_to_phys(domain->pgtable);
> + struct exynos_iommu_domain *domain;
> + phys_addr_t pagetable;
> struct sysmmu_drvdata *data, *next;
> unsigned long flags;
>
> - if (!has_sysmmu(dev) || owner->domain != iommu_domain)
> - return;
> + if (owner->domain == identity_domain)
> + return 0;
> +
> + domain = to_exynos_domain(owner->domain);
> + pagetable = virt_to_phys(domain->pgtable);
>
> mutex_lock(&owner->rpm_lock);
>
> @@ -1009,15 +1013,25 @@ static void exynos_iommu_detach_device(struct iommu_domain *iommu_domain,
> list_del_init(&data->domain_node);
> spin_unlock(&data->lock);
> }
> - owner->domain = NULL;
> + owner->domain = identity_domain;
> spin_unlock_irqrestore(&domain->lock, flags);
>
> mutex_unlock(&owner->rpm_lock);
>
> - dev_dbg(dev, "%s: Detached IOMMU with pgtable %pa\n", __func__,
> - &pagetable);
> + dev_dbg(dev, "%s: Restored IOMMU to IDENTITY from pgtable %pa\n",
> + __func__, &pagetable);
> + return 0;
> }
>
> +static struct iommu_domain_ops exynos_identity_ops = {
> + .attach_dev = exynos_iommu_identity_attach,
> +};
> +
> +static struct iommu_domain exynos_identity_domain = {
> + .type = IOMMU_DOMAIN_IDENTITY,
> + .ops = &exynos_identity_ops,
> +};
> +
> static int exynos_iommu_attach_device(struct iommu_domain *iommu_domain,
> struct device *dev)
> {
> @@ -1026,12 +1040,11 @@ static int exynos_iommu_attach_device(struct iommu_domain *iommu_domain,
> struct sysmmu_drvdata *data;
> phys_addr_t pagetable = virt_to_phys(domain->pgtable);
> unsigned long flags;
> + int err;
>
> - if (!has_sysmmu(dev))
> - return -ENODEV;
> -
> - if (owner->domain)
> - exynos_iommu_detach_device(owner->domain, dev);
> + err = exynos_iommu_identity_attach(&exynos_identity_domain, dev);
> + if (err)
> + return err;
>
> mutex_lock(&owner->rpm_lock);
>
> @@ -1407,26 +1420,12 @@ static struct iommu_device *exynos_iommu_probe_device(struct device *dev)
> return &data->iommu;
> }
>
> -static void exynos_iommu_set_platform_dma(struct device *dev)
> -{
> - struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
> -
> - if (owner->domain) {
> - struct iommu_group *group = iommu_group_get(dev);
> -
> - if (group) {
> - exynos_iommu_detach_device(owner->domain, dev);
> - iommu_group_put(group);
> - }
> - }
> -}
> -
> static void exynos_iommu_release_device(struct device *dev)
> {
> struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
> struct sysmmu_drvdata *data;
>
> - exynos_iommu_set_platform_dma(dev);
> + WARN_ON(exynos_iommu_identity_attach(&exynos_identity_domain, dev));
>
> list_for_each_entry(data, &owner->controllers, owner_node)
> device_link_del(data->link);
> @@ -1457,6 +1456,7 @@ static int exynos_iommu_of_xlate(struct device *dev,
>
> INIT_LIST_HEAD(&owner->controllers);
> mutex_init(&owner->rpm_lock);
> + owner->domain = &exynos_identity_domain;
> dev_iommu_priv_set(dev, owner);
> }
>
> @@ -1471,11 +1471,9 @@ static int exynos_iommu_of_xlate(struct device *dev,
> }
>
> static const struct iommu_ops exynos_iommu_ops = {
> + .identity_domain = &exynos_identity_domain,
> .domain_alloc = exynos_iommu_domain_alloc,
> .device_group = generic_device_group,
> -#ifdef CONFIG_ARM
> - .set_platform_dma_ops = exynos_iommu_set_platform_dma,
> -#endif
> .probe_device = exynos_iommu_probe_device,
> .release_device = exynos_iommu_release_device,
> .pgsize_bitmap = SECT_SIZE | LPAGE_SIZE | SPAGE_SIZE,
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
