[PATCH 4/6] iommu: remove iommu_aux_{attach,detach}_device

Christoph Hellwig
2021-05-10T06:54:36Z

These are entirely unused now, and were only called by the previously
entirely unused vfio mdev iommu interaction.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/iommu/intel/iommu.c | 205 ------------------------------------
drivers/iommu/iommu.c | 33 ------
include/linux/intel-iommu.h | 10 --
include/linux/iommu.h | 17 ---
4 files changed, 265 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index cc07f316adcb18..6cae6e4d693226 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1497,18 +1497,6 @@ static void domain_update_iotlb(struct dmar_domain *domain)
break;
}

- if (!has_iotlb_device) {
- struct subdev_domain_info *sinfo;
-
- list_for_each_entry(sinfo, &domain->subdevices, link_domain) {
- info = get_domain_info(sinfo->pdev);
- if (info && info->ats_enabled) {
- has_iotlb_device = true;
- break;
- }
- }
- }
-
domain->has_iotlb_device = has_iotlb_device;
}

@@ -1606,7 +1594,6 @@ static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
{
unsigned long flags;
struct device_domain_info *info;
- struct subdev_domain_info *sinfo;

if (!domain->has_iotlb_device)
return;
@@ -1614,11 +1601,6 @@ static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
spin_lock_irqsave(&device_domain_lock, flags);
list_for_each_entry(info, &domain->devices, link)
__iommu_flush_dev_iotlb(info, addr, mask);
-
- list_for_each_entry(sinfo, &domain->subdevices, link_domain) {
- info = get_domain_info(sinfo->pdev);
- __iommu_flush_dev_iotlb(info, addr, mask);
- }
spin_unlock_irqrestore(&device_domain_lock, flags);
}

@@ -1903,7 +1885,6 @@ static struct dmar_domain *alloc_domain(int flags)
domain->flags |= DOMAIN_FLAG_USE_FIRST_LEVEL;
domain->has_iotlb_device = false;
INIT_LIST_HEAD(&domain->devices);
- INIT_LIST_HEAD(&domain->subdevices);

return domain;
}
@@ -2593,7 +2574,6 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
info->iommu = iommu;
info->pasid_table = NULL;
info->auxd_enabled = 0;
- INIT_LIST_HEAD(&info->subdevices);

if (dev && dev_is_pci(dev)) {
struct pci_dev *pdev = to_pci_dev(info->dev);
@@ -4579,168 +4559,6 @@ is_aux_domain(struct device *dev, struct iommu_domain *domain)
domain->type == IOMMU_DOMAIN_UNMANAGED;
}

-static inline struct subdev_domain_info *
-lookup_subdev_info(struct dmar_domain *domain, struct device *dev)
-{
- struct subdev_domain_info *sinfo;
-
- if (!list_empty(&domain->subdevices)) {
- list_for_each_entry(sinfo, &domain->subdevices, link_domain) {
- if (sinfo->pdev == dev)
- return sinfo;
- }
- }
-
- return NULL;
-}
-
-static int auxiliary_link_device(struct dmar_domain *domain,
- struct device *dev)
-{
- struct device_domain_info *info = get_domain_info(dev);
- struct subdev_domain_info *sinfo = lookup_subdev_info(domain, dev);
-
- assert_spin_locked(&device_domain_lock);
- if (WARN_ON(!info))
- return -EINVAL;
-
- if (!sinfo) {
- sinfo = kzalloc(sizeof(*sinfo), GFP_ATOMIC);
- sinfo->domain = domain;
- sinfo->pdev = dev;
- list_add(&sinfo->link_phys, &info->subdevices);
- list_add(&sinfo->link_domain, &domain->subdevices);
- }
-
- return ++sinfo->users;
-}
-
-static int auxiliary_unlink_device(struct dmar_domain *domain,
- struct device *dev)
-{
- struct device_domain_info *info = get_domain_info(dev);
- struct subdev_domain_info *sinfo = lookup_subdev_info(domain, dev);
- int ret;
-
- assert_spin_locked(&device_domain_lock);
- if (WARN_ON(!info || !sinfo || sinfo->users <= 0))
- return -EINVAL;
-
- ret = --sinfo->users;
- if (!ret) {
- list_del(&sinfo->link_phys);
- list_del(&sinfo->link_domain);
- kfree(sinfo);
- }
-
- return ret;
-}
-
-static int aux_domain_add_dev(struct dmar_domain *domain,
- struct device *dev)
-{
- int ret;
- unsigned long flags;
- struct intel_iommu *iommu;
-
- iommu = device_to_iommu(dev, NULL, NULL);
- if (!iommu)
- return -ENODEV;
-
- if (domain->default_pasid <= 0) {
- u32 pasid;
-
- /* No private data needed for the default pasid */
- pasid = ioasid_alloc(NULL, PASID_MIN,
- pci_max_pasids(to_pci_dev(dev)) - 1,
- NULL);
- if (pasid == INVALID_IOASID) {
- pr_err("Can't allocate default pasid\n");
- return -ENODEV;
- }
- domain->default_pasid = pasid;
- }
-
- spin_lock_irqsave(&device_domain_lock, flags);
- ret = auxiliary_link_device(domain, dev);
- if (ret <= 0)
- goto link_failed;
-
- /*
- * Subdevices from the same physical device can be attached to the
- * same domain. For such cases, only the first subdevice attachment
- * needs to go through the full steps in this function. So if ret >
- * 1, just goto out.
- */
- if (ret > 1)
- goto out;
-
- /*
- * iommu->lock must be held to attach domain to iommu and setup the
- * pasid entry for second level translation.
- */
- spin_lock(&iommu->lock);
- ret = domain_attach_iommu(domain, iommu);
- if (ret)
- goto attach_failed;
-
- /* Setup the PASID entry for mediated devices: */
- if (domain_use_first_level(domain))
- ret = domain_setup_first_level(iommu, domain, dev,
- domain->default_pasid);
- else
- ret = intel_pasid_setup_second_level(iommu, domain, dev,
- domain->default_pasid);
- if (ret)
- goto table_failed;
-
- spin_unlock(&iommu->lock);
-out:
- spin_unlock_irqrestore(&device_domain_lock, flags);
-
- return 0;
-
-table_failed:
- domain_detach_iommu(domain, iommu);
-attach_failed:
- spin_unlock(&iommu->lock);
- auxiliary_unlink_device(domain, dev);
-link_failed:
- spin_unlock_irqrestore(&device_domain_lock, flags);
- if (list_empty(&domain->subdevices) && domain->default_pasid > 0)
- ioasid_put(domain->default_pasid);
-
- return ret;
-}
-
-static void aux_domain_remove_dev(struct dmar_domain *domain,
- struct device *dev)
-{
- struct device_domain_info *info;
- struct intel_iommu *iommu;
- unsigned long flags;
-
- if (!is_aux_domain(dev, &domain->domain))
- return;
-
- spin_lock_irqsave(&device_domain_lock, flags);
- info = get_domain_info(dev);
- iommu = info->iommu;
-
- if (!auxiliary_unlink_device(domain, dev)) {
- spin_lock(&iommu->lock);
- intel_pasid_tear_down_entry(iommu, dev,
- domain->default_pasid, false);
- domain_detach_iommu(domain, iommu);
- spin_unlock(&iommu->lock);
- }
-
- spin_unlock_irqrestore(&device_domain_lock, flags);
-
- if (list_empty(&domain->subdevices) && domain->default_pasid > 0)
- ioasid_put(domain->default_pasid);
-}
-
static int prepare_domain_attach_device(struct iommu_domain *domain,
struct device *dev)
{
@@ -4813,33 +4631,12 @@ static int intel_iommu_attach_device(struct iommu_domain *domain,
return domain_add_dev_info(to_dmar_domain(domain), dev);
}

-static int intel_iommu_aux_attach_device(struct iommu_domain *domain,
- struct device *dev)
-{
- int ret;
-
- if (!is_aux_domain(dev, domain))
- return -EPERM;
-
- ret = prepare_domain_attach_device(domain, dev);
- if (ret)
- return ret;
-
- return aux_domain_add_dev(to_dmar_domain(domain), dev);
-}
-
static void intel_iommu_detach_device(struct iommu_domain *domain,
struct device *dev)
{
dmar_remove_one_dev_info(dev);
}

-static void intel_iommu_aux_detach_device(struct iommu_domain *domain,
- struct device *dev)
-{
- aux_domain_remove_dev(to_dmar_domain(domain), dev);
-}
-
#ifdef CONFIG_INTEL_IOMMU_SVM
/*
* 2D array for converting and sanitizing IOMMU generic TLB granularity to
@@ -5474,8 +5271,6 @@ const struct iommu_ops intel_iommu_ops = {
.enable_nesting = intel_iommu_enable_nesting,
.attach_dev = intel_iommu_attach_device,
.detach_dev = intel_iommu_detach_device,
- .aux_attach_dev = intel_iommu_aux_attach_device,
- .aux_detach_dev = intel_iommu_aux_detach_device,
.map = intel_iommu_map,
.iotlb_sync_map = intel_iommu_iotlb_sync_map,
.unmap = intel_iommu_unmap,
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 6721ac17baf29b..c4b92270946c2f 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2901,39 +2901,6 @@ bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features feat)
}
EXPORT_SYMBOL_GPL(iommu_dev_feature_enabled);

-/*
- * Aux-domain specific attach/detach.
- *
- * Only works if iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX) returns
- * true. Also, as long as domains are attached to a device through this
- * interface, any tries to call iommu_attach_device() should fail
- * (iommu_detach_device() can't fail, so we fail when trying to re-attach).
- * This should make us safe against a device being attached to a guest as a
- * whole while there are still pasid users on it (aux and sva).
- */
-int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev)
-{
- int ret = -ENODEV;
-
- if (domain->ops->aux_attach_dev)
- ret = domain->ops->aux_attach_dev(domain, dev);
-
- if (!ret)
- trace_attach_device_to_domain(dev);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(iommu_aux_attach_device);
-
-void iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev)
-{
- if (domain->ops->aux_detach_dev) {
- domain->ops->aux_detach_dev(domain, dev);
- trace_detach_device_from_domain(dev);
- }
-}
-EXPORT_SYMBOL_GPL(iommu_aux_detach_device);
-
/**
* iommu_sva_bind_device() - Bind a process address space to a device
* @dev: the device
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 03faf20a6817e8..c12b8e6545733c 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -548,7 +548,6 @@ struct dmar_domain {

bool has_iotlb_device;
struct list_head devices; /* all devices' list */
- struct list_head subdevices; /* all subdevices' list */
struct iova_domain iovad; /* iova's that belong to this domain */

struct dma_pte *pgd; /* virtual address */
@@ -621,15 +620,6 @@ struct intel_iommu {
struct dmar_drhd_unit *drhd;
};

-/* Per subdevice private data */
-struct subdev_domain_info {
- struct list_head link_phys; /* link to phys device siblings */
- struct list_head link_domain; /* link to domain siblings */
- struct device *pdev; /* physical device derived from */
- struct dmar_domain *domain; /* aux-domain */
- int users; /* user count */
-};
-
/* PCI domain-device relationship */
struct device_domain_info {
struct list_head link; /* link to domain siblings */
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index d8aa5c8a5ba57a..b0bf99dfd80d16 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -258,10 +258,6 @@ struct iommu_ops {
int (*dev_enable_feat)(struct device *dev, enum iommu_dev_features f);
int (*dev_disable_feat)(struct device *dev, enum iommu_dev_features f);

- /* Aux-domain specific attach/detach entries */
- int (*aux_attach_dev)(struct iommu_domain *domain, struct device *dev);
- void (*aux_detach_dev)(struct iommu_domain *domain, struct device *dev);
-
struct iommu_sva *(*sva_bind)(struct device *dev, struct mm_struct *mm,
void *drvdata);
void (*sva_unbind)(struct iommu_sva *handle);
@@ -590,8 +586,6 @@ void iommu_release_device(struct device *dev);
int iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features f);
int iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features f);
bool iommu_dev_feature_enabled(struct device *dev, enum iommu_dev_features f);
-int iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev);
-void iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev);

struct iommu_sva *iommu_sva_bind_device(struct device *dev,
struct mm_struct *mm,
@@ -931,17 +925,6 @@ iommu_dev_disable_feature(struct device *dev, enum iommu_dev_features feat)
return -ENODEV;
}

-static inline int
-iommu_aux_attach_device(struct iommu_domain *domain, struct device *dev)
-{
- return -ENODEV;
-}
-
-static inline void
-iommu_aux_detach_device(struct iommu_domain *domain, struct device *dev)
-{
-}
-
static inline struct iommu_sva *
iommu_sva_bind_device(struct device *dev, struct mm_struct *mm, void *drvdata)
{
--
2.30.2