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iommu/exynos: Implement an IDENTITY domain
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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.

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/10-v8-81230027b2fa+9d-iommu_all_defdom_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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Jason Gunthorpe authored and Joerg Roedel committed Sep 25, 2023
1 parent e98befd commit b3d1496
Showing 1 changed file with 32 additions and 34 deletions.
66 changes: 32 additions & 34 deletions drivers/iommu/exynos-iommu.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -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);
}
Expand All @@ -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);
}
Expand Down Expand Up @@ -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);

Expand All @@ -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)
{
Expand All @@ -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);

Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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);
}

Expand All @@ -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,
Expand Down

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