[Intel-gfx] [PATCH v2 10/10] iommu/vt-d: Add callback to device driver on page faults
David Woodhouse
dwmw2 at infradead.org
Tue Oct 13 14:35:48 PDT 2015
Signed-off-by: David Woodhouse <David.Woodhouse at intel.com>
---
drivers/iommu/intel-iommu.c | 3 ++-
drivers/iommu/intel-svm.c | 26 +++++++++++++++++++++++++-
include/linux/intel-iommu.h | 3 +++
include/linux/intel-svm.h | 21 ++++++++++++++++++---
4 files changed, 48 insertions(+), 5 deletions(-)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 548f6e5..4f2eab6 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -5029,12 +5029,13 @@ int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct intel_svm_dev *sd
if (!info->pasid_enabled)
iommu_enable_dev_iotlb(info);
+ sdev->sid = (((u16)bus) << 8) | devfn;
+
if (info->ats_enabled) {
sdev->dev_iotlb = 1;
sdev->qdep = info->ats_qdep;
if (sdev->qdep >= QI_DEV_EIOTLB_MAX_INVS)
sdev->qdep = 0;
- sdev->sid = (((u16)bus) << 8) | devfn;
}
return 0;
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 0e86542..0a31350 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -264,7 +264,7 @@ static const struct mmu_notifier_ops intel_mmuops = {
static DEFINE_MUTEX(pasid_mutex);
-int intel_svm_bind_mm(struct device *dev, int *pasid)
+int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ops *ops)
{
struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
struct intel_svm_dev *sdev;
@@ -302,6 +302,10 @@ int intel_svm_bind_mm(struct device *dev, int *pasid)
list_for_each_entry(sdev, &svm->devs, list) {
if (dev == sdev->dev) {
+ if (sdev->ops != ops) {
+ ret = -EBUSY;
+ goto out;
+ }
sdev->users++;
goto success;
}
@@ -327,6 +331,7 @@ int intel_svm_bind_mm(struct device *dev, int *pasid)
}
/* Finish the setup now we know we're keeping it */
sdev->users = 1;
+ sdev->ops = ops;
init_rcu_head(&sdev->rcu);
if (!svm) {
@@ -456,6 +461,7 @@ static irqreturn_t prq_event_thread(int irq, void *d)
tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK;
head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK;
while (head != tail) {
+ struct intel_svm_dev *sdev;
struct vm_area_struct *vma;
struct page_req_dsc *req;
struct qi_desc resp;
@@ -507,6 +513,24 @@ static irqreturn_t prq_event_thread(int irq, void *d)
up_read(&svm->mm->mmap_sem);
bad_req:
/* Accounting for major/minor faults? */
+ rcu_read_lock();
+ list_for_each_entry_rcu(sdev, &svm->devs, list) {
+ if (sdev->sid == ((req->bus << 8) | req->devfn))
+ break;
+ }
+ /* Other devices can go away, but the drivers are not permitted
+ * to unbind while any page faults might be in flight. So it's
+ * OK to drop the 'lock' here now we have it. */
+ rcu_read_unlock();
+
+ if (WARN_ON(&sdev->list == &svm->devs))
+ sdev = NULL;
+
+ if (sdev && sdev->ops && sdev->ops->fault_cb) {
+ int rwxp = (req->rd_req << 3) | (req->wr_req << 2) |
+ (req->wr_req << 1) | (req->exe_req);
+ sdev->ops->fault_cb(sdev->dev, req->pasid, req->addr, req->private, rwxp, result);
+ }
if (req->lpig) {
/* Page Group Response */
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index e5b80d3..57be14f 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -472,10 +472,13 @@ extern int intel_svm_free_pasid_tables(struct intel_iommu *iommu);
extern int intel_svm_enable_prq(struct intel_iommu *iommu);
extern int intel_svm_finish_prq(struct intel_iommu *iommu);
+struct svm_dev_ops;
+
struct intel_svm_dev {
struct list_head list;
struct rcu_head rcu;
struct device *dev;
+ struct svm_dev_ops *ops;
int users;
u16 did;
u16 dev_iotlb:1;
diff --git a/include/linux/intel-svm.h b/include/linux/intel-svm.h
index 42f80ad..239f8a1 100644
--- a/include/linux/intel-svm.h
+++ b/include/linux/intel-svm.h
@@ -20,10 +20,23 @@
struct device;
+struct svm_dev_ops {
+ void (*fault_cb)(struct device *dev, int pasid, u64 address,
+ u32 private, int rwxp, int response);
+};
+
+/* Values for rxwp in fault_cb callback */
+#define SVM_REQ_READ (1<<3)
+#define SVM_REQ_WRITE (1<<2)
+#define SVM_REQ_EXEC (1<<1)
+#define SVM_REQ_PRIV (1<<0)
+
/**
* intel_svm_bind_mm() - Bind the current process to a PASID
* @dev: Device to be granted acccess
* @pasid: Address for allocated PASID
+ * @flags: Flags. Later for requesting supervisor mode, etc.
+ * @ops: Callbacks to device driver
*
* This function attempts to enable PASID support for the given device.
* If the @pasid argument is non-%NULL, a PASID is allocated for access
@@ -45,7 +58,8 @@ struct device;
* Multiple calls from the same process may result in the same PASID
* being re-used. A reference count is kept.
*/
-extern int intel_svm_bind_mm(struct device *dev, int *pasid);
+extern int intel_svm_bind_mm(struct device *dev, int *pasid, int flags,
+ struct svm_dev_ops *ops);
/**
* intel_svm_unbind_mm() - Unbind a specified PASID
@@ -66,7 +80,8 @@ extern int intel_svm_unbind_mm(struct device *dev, int pasid);
#else /* CONFIG_INTEL_IOMMU_SVM */
-static inline int intel_svm_bind_mm(struct device *dev, int *pasid)
+static inline int intel_svm_bind_mm(struct device *dev, int *pasid,
+ int flags, struct svm_dev_ops *ops)
{
return -ENOSYS;
}
@@ -77,6 +92,6 @@ static inline int intel_svm_unbind_mm(struct device *dev, int pasid)
}
#endif /* CONFIG_INTEL_IOMMU_SVM */
-#define intel_svm_available(dev) (!intel_svm_bind_mm((dev), NULL))
+#define intel_svm_available(dev) (!intel_svm_bind_mm((dev), NULL, 0, NULL))
#endif /* __INTEL_SVM_H__ */
--
2.4.3
--
David Woodhouse Open Source Technology Centre
David.Woodhouse at intel.com Intel Corporation
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