iommu/vt-d: Add callback to device driver on page faults (0204a496) · Commits · e / devices / android_kernel_oneplus_sm8150

drivers/iommu/intel-svm.c

+25 −1

Original line number	Diff line number	Diff line
		@@ -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 == PCI_DEVID(req->bus, 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 */

include/linux/intel-iommu.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -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;

include/linux/intel-svm.h

+18 −3

Original line number	Diff line number	Diff line
		@@ -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__ */