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iommu/vt-d: Add pasid private data helpers
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We are about to use iommu_sva_alloc/free_pasid() helpers in iommu core.
That means the pasid life cycle will be managed by iommu core. Use a
local array to save the per pasid private data instead of attaching it
the real pasid.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210520031531.712333-1-baolu.lu@linux.intel.com
Link: https://lore.kernel.org/r/20210610020115.1637656-7-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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Lu Baolu authored and Joerg Roedel committed Jun 10, 2021
1 parent 521f546 commit 100b8a1
Showing 1 changed file with 41 additions and 21 deletions.
62 changes: 41 additions & 21 deletions drivers/iommu/intel/svm.c
Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,7 @@
#include <linux/dmar.h>
#include <linux/interrupt.h>
#include <linux/mm_types.h>
#include <linux/xarray.h>
#include <linux/ioasid.h>
#include <asm/page.h>
#include <asm/fpu/api.h>
Expand All @@ -28,6 +29,23 @@ static void intel_svm_drain_prq(struct device *dev, u32 pasid);

#define PRQ_ORDER 0

static DEFINE_XARRAY_ALLOC(pasid_private_array);
static int pasid_private_add(ioasid_t pasid, void *priv)
{
return xa_alloc(&pasid_private_array, &pasid, priv,
XA_LIMIT(pasid, pasid), GFP_ATOMIC);
}

static void pasid_private_remove(ioasid_t pasid)
{
xa_erase(&pasid_private_array, pasid);
}

static void *pasid_private_find(ioasid_t pasid)
{
return xa_load(&pasid_private_array, pasid);
}

int intel_svm_enable_prq(struct intel_iommu *iommu)
{
struct page *pages;
Expand Down Expand Up @@ -224,7 +242,7 @@ static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid,
if (pasid == INVALID_IOASID || pasid >= PASID_MAX)
return -EINVAL;

svm = ioasid_find(NULL, pasid, NULL);
svm = pasid_private_find(pasid);
if (IS_ERR(svm))
return PTR_ERR(svm);

Expand Down Expand Up @@ -334,7 +352,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
svm->gpasid = data->gpasid;
svm->flags |= SVM_FLAG_GUEST_PASID;
}
ioasid_set_data(data->hpasid, svm);
pasid_private_add(data->hpasid, svm);
INIT_LIST_HEAD_RCU(&svm->devs);
mmput(svm->mm);
}
Expand Down Expand Up @@ -388,7 +406,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
list_add_rcu(&sdev->list, &svm->devs);
out:
if (!IS_ERR_OR_NULL(svm) && list_empty(&svm->devs)) {
ioasid_set_data(data->hpasid, NULL);
pasid_private_remove(data->hpasid);
kfree(svm);
}

Expand Down Expand Up @@ -431,7 +449,7 @@ int intel_svm_unbind_gpasid(struct device *dev, u32 pasid)
* the unbind, IOMMU driver will get notified
* and perform cleanup.
*/
ioasid_set_data(pasid, NULL);
pasid_private_remove(pasid);
kfree(svm);
}
}
Expand Down Expand Up @@ -547,22 +565,24 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags,
svm = kzalloc(sizeof(*svm), GFP_KERNEL);
if (!svm) {
ret = -ENOMEM;
kfree(sdev);
goto out;
goto sdev_err;
}

if (pasid_max > intel_pasid_max_id)
pasid_max = intel_pasid_max_id;

/* Do not use PASID 0, reserved for RID to PASID */
svm->pasid = ioasid_alloc(NULL, PASID_MIN,
pasid_max - 1, svm);
pasid_max - 1, NULL);
if (svm->pasid == INVALID_IOASID) {
kfree(svm);
kfree(sdev);
ret = -ENOSPC;
goto out;
goto svm_err;
}

ret = pasid_private_add(svm->pasid, svm);
if (ret)
goto pasid_err;

svm->notifier.ops = &intel_mmuops;
svm->mm = mm;
svm->flags = flags;
Expand All @@ -571,12 +591,8 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags,
ret = -ENOMEM;
if (mm) {
ret = mmu_notifier_register(&svm->notifier, mm);
if (ret) {
ioasid_put(svm->pasid);
kfree(svm);
kfree(sdev);
goto out;
}
if (ret)
goto priv_err;
}

spin_lock_irqsave(&iommu->lock, iflags);
Expand All @@ -590,8 +606,13 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags,
if (ret) {
if (mm)
mmu_notifier_unregister(&svm->notifier, mm);
priv_err:
pasid_private_remove(svm->pasid);
pasid_err:
ioasid_put(svm->pasid);
svm_err:
kfree(svm);
sdev_err:
kfree(sdev);
goto out;
}
Expand All @@ -614,10 +635,8 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags,
(cpu_feature_enabled(X86_FEATURE_LA57) ?
PASID_FLAG_FL5LP : 0));
spin_unlock_irqrestore(&iommu->lock, iflags);
if (ret) {
kfree(sdev);
goto out;
}
if (ret)
goto sdev_err;
}
list_add_rcu(&sdev->list, &svm->devs);
success:
Expand Down Expand Up @@ -670,6 +689,7 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid)
load_pasid(svm->mm, PASID_DISABLED);
}
list_del(&svm->list);
pasid_private_remove(svm->pasid);
/* We mandate that no page faults may be outstanding
* for the PASID when intel_svm_unbind_mm() is called.
* If that is not obeyed, subtle errors will happen.
Expand Down Expand Up @@ -924,7 +944,7 @@ static irqreturn_t prq_event_thread(int irq, void *d)
}
if (!svm || svm->pasid != req->pasid) {
rcu_read_lock();
svm = ioasid_find(NULL, req->pasid, NULL);
svm = pasid_private_find(req->pasid);
/* It *can't* go away, because the driver is not permitted
* to unbind the mm while any page faults are outstanding.
* So we only need RCU to protect the internal idr code. */
Expand Down

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