svn commit: r368749 - head/sys/dev/pci

[Konstantin Belousov]

Author: kib
Date: Fri Dec 18 03:46:50 2020
New Revision: 368749
URL: https://svnweb.freebsd.org/changeset/base/368749

Log:
  pci_iov: When pci_iov_detach(9) is called, destroy VF children
  
  instead of bailing out with EBUSY if there are any.
  
  If driver module is unloaded, or just device is forcibly detached from
  the driver, there is no way for driver to correctly unload otherwise.
  Esp. if there are resources dedicated to the VFs which prevent turning
  down other resources.
  
  Reviewed by:	jhb
  Sponsored by:	Mellanox Technologies / NVidia Networking
  MFC after:	1 week
  Differential revision:	https://reviews.freebsd.org/D27615

Modified:
  head/sys/dev/pci/pci_iov.c

Modified: head/sys/dev/pci/pci_iov.c
==============================================================================
--- head/sys/dev/pci/pci_iov.c	Fri Dec 18 02:41:12 2020	(r368748)
+++ head/sys/dev/pci/pci_iov.c	Fri Dec 18 03:46:50 2020	(r368749)
@@ -95,6 +95,7 @@ static void	pci_iov_build_pf_schema(nvlist_t *schema,
 		    nvlist_t **driver_schema);
 static void	pci_iov_build_vf_schema(nvlist_t *schema,
 		    nvlist_t **driver_schema);
+static int	pci_iov_delete_iov_children(struct pci_devinfo *dinfo);
 static nvlist_t	*pci_iov_get_pf_subsystem_schema(void);
 static nvlist_t	*pci_iov_get_vf_subsystem_schema(void);
 
@@ -191,6 +192,7 @@ pci_iov_detach_method(device_t bus, device_t dev)
 {
 	struct pci_devinfo *dinfo;
 	struct pcicfg_iov *iov;
+	int error;
 
 	mtx_lock(&Giant);
 	dinfo = device_get_ivars(dev);
@@ -201,11 +203,17 @@ pci_iov_detach_method(device_t bus, device_t dev)
 		return (0);
 	}
 
-	if (iov->iov_num_vfs != 0 || iov->iov_flags & IOV_BUSY) {
+	if ((iov->iov_flags & IOV_BUSY) != 0) {
 		mtx_unlock(&Giant);
 		return (EBUSY);
 	}
 
+	error = pci_iov_delete_iov_children(dinfo);
+	if (error != 0) {
+		mtx_unlock(&Giant);
+		return (error);
+	}
+
 	dinfo->cfg.iov = NULL;
 
 	if (iov->iov_cdev) {
@@ -823,31 +831,20 @@ pci_iov_is_child_vf(struct pcicfg_iov *pf, device_t ch
 }
 
 static int
-pci_iov_delete(struct cdev *cdev)
+pci_iov_delete_iov_children(struct pci_devinfo *dinfo)
 {
 	device_t bus, dev, vf, *devlist;
-	struct pci_devinfo *dinfo;
 	struct pcicfg_iov *iov;
 	int i, error, devcount;
 	uint32_t iov_ctl;
 
-	mtx_lock(&Giant);
-	dinfo = cdev->si_drv1;
+	mtx_assert(&Giant, MA_OWNED);
+
 	iov = dinfo->cfg.iov;
 	dev = dinfo->cfg.dev;
 	bus = device_get_parent(dev);
 	devlist = NULL;
 
-	if (iov->iov_flags & IOV_BUSY) {
-		mtx_unlock(&Giant);
-		return (EBUSY);
-	}
-
-	if (iov->iov_num_vfs == 0) {
-		mtx_unlock(&Giant);
-		return (ECHILD);
-	}
-
 	iov->iov_flags |= IOV_BUSY;
 
 	error = device_get_children(bus, &devlist, &devcount);
@@ -905,6 +902,32 @@ pci_iov_delete(struct cdev *cdev)
 out:
 	free(devlist, M_TEMP);
 	iov->iov_flags &= ~IOV_BUSY;
+	return (error);
+}
+
+static int
+pci_iov_delete(struct cdev *cdev)
+{
+	struct pci_devinfo *dinfo;
+	struct pcicfg_iov *iov;
+	int error;
+
+	mtx_lock(&Giant);
+	dinfo = cdev->si_drv1;
+	iov = dinfo->cfg.iov;
+
+	if ((iov->iov_flags & IOV_BUSY) != 0) {
+		error = EBUSY;
+		goto out;
+	}
+	if (iov->iov_num_vfs == 0) {
+		error = ECHILD;
+		goto out;
+	}
+
+	error = pci_iov_delete_iov_children(dinfo);
+
+out:
 	mtx_unlock(&Giant);
 	return (error);
 }