1 files changed, 108 insertions, 1 deletions

diff --git a/drivers/pci/tsm.c b/drivers/pci/tsm.c
index 6a2849f77adc..39de91a47a26 100644
--- a/drivers/pci/tsm.c
+++ b/drivers/pci/tsm.c
@@ -270,6 +270,95 @@ static int remove_fn(struct pci_dev *pdev, void *data)
 	return 0;
 }
 
+/*
+ * Note, this helper only returns an error code and takes an argument for
+ * compatibility with the pci_walk_bus() callback prototype. pci_tsm_unbind()
+ * always succeeds.
+ */
+static int __pci_tsm_unbind(struct pci_dev *pdev, void *data)
+{
+	struct pci_tdi *tdi;
+	struct pci_tsm_pf0 *tsm_pf0;
+
+	lockdep_assert_held(&pci_tsm_rwsem);
+
+	if (!pdev->tsm)
+		return 0;
+
+	tsm_pf0 = to_pci_tsm_pf0(pdev->tsm);
+	guard(mutex)(&tsm_pf0->lock);
+
+	tdi = pdev->tsm->tdi;
+	if (!tdi)
+		return 0;
+
+	to_pci_tsm_ops(pdev->tsm)->unbind(tdi);
+	pdev->tsm->tdi = NULL;
+
+	return 0;
+}
+
+void pci_tsm_unbind(struct pci_dev *pdev)
+{
+	guard(rwsem_read)(&pci_tsm_rwsem);
+	__pci_tsm_unbind(pdev, NULL);
+}
+EXPORT_SYMBOL_GPL(pci_tsm_unbind);
+
+/**
+ * pci_tsm_bind() - Bind @pdev as a TDI for @kvm
+ * @pdev: PCI device function to bind
+ * @kvm: Private memory attach context
+ * @tdi_id: Identifier (virtual BDF) for the TDI as referenced by the TSM and DSM
+ *
+ * Returns 0 on success, or a negative error code on failure.
+ *
+ * Context: Caller is responsible for constraining the bind lifetime to the
+ * registered state of the device. For example, pci_tsm_bind() /
+ * pci_tsm_unbind() limited to the VFIO driver bound state of the device.
+ */
+int pci_tsm_bind(struct pci_dev *pdev, struct kvm *kvm, u32 tdi_id)
+{
+	struct pci_tsm_pf0 *tsm_pf0;
+	struct pci_tdi *tdi;
+
+	if (!kvm)
+		return -EINVAL;
+
+	guard(rwsem_read)(&pci_tsm_rwsem);
+
+	if (!pdev->tsm)
+		return -EINVAL;
+
+	if (!is_link_tsm(pdev->tsm->tsm_dev))
+		return -ENXIO;
+
+	tsm_pf0 = to_pci_tsm_pf0(pdev->tsm);
+	guard(mutex)(&tsm_pf0->lock);
+
+	/* Resolve races to bind a TDI */
+	if (pdev->tsm->tdi) {
+		if (pdev->tsm->tdi->kvm != kvm)
+			return -EBUSY;
+		return 0;
+	}
+
+	tdi = to_pci_tsm_ops(pdev->tsm)->bind(pdev, kvm, tdi_id);
+	if (IS_ERR(tdi))
+		return PTR_ERR(tdi);
+
+	pdev->tsm->tdi = tdi;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pci_tsm_bind);
+
+static void pci_tsm_unbind_all(struct pci_dev *pdev)
+{
+	pci_tsm_walk_fns_reverse(pdev, __pci_tsm_unbind, NULL);
+	__pci_tsm_unbind(pdev, NULL);
+}
+
 static void __pci_tsm_disconnect(struct pci_dev *pdev)
 {
 	struct pci_tsm_pf0 *tsm_pf0 = to_pci_tsm_pf0(pdev->tsm);
@@ -278,6 +367,8 @@ static void __pci_tsm_disconnect(struct pci_dev *pdev)
 	/* disconnect() mutually exclusive with subfunction pci_tsm_init() */
 	lockdep_assert_held_write(&pci_tsm_rwsem);
 
+	pci_tsm_unbind_all(pdev);
+
 	/*
 	 * disconnect() is uninterruptible as it may be called for device
 	 * teardown
@@ -440,6 +531,22 @@ static struct pci_dev *find_dsm_dev(struct pci_dev *pdev)
 }
 
 /**
+ * pci_tsm_tdi_constructor() - base 'struct pci_tdi' initialization for link TSMs
+ * @pdev: PCI device function representing the TDI
+ * @tdi: context to initialize
+ * @kvm: Private memory attach context
+ * @tdi_id: Identifier (virtual BDF) for the TDI as referenced by the TSM and DSM
+ */
+void pci_tsm_tdi_constructor(struct pci_dev *pdev, struct pci_tdi *tdi,
+			     struct kvm *kvm, u32 tdi_id)
+{
+	tdi->pdev = pdev;
+	tdi->kvm = kvm;
+	tdi->tdi_id = tdi_id;
+}
+EXPORT_SYMBOL_GPL(pci_tsm_tdi_constructor);
+
+/**
  * pci_tsm_link_constructor() - base 'struct pci_tsm' initialization for link TSMs
  * @pdev: The PCI device
  * @tsm: context to initialize
@@ -532,7 +639,7 @@ int pci_tsm_register(struct tsm_dev *tsm_dev)
 
 static void pci_tsm_fn_exit(struct pci_dev *pdev)
 {
-	/* TODO: unbind the fn */
+	__pci_tsm_unbind(pdev, NULL);
 	tsm_remove(pdev->tsm);
 }