MFC 303721: Permit the name of the /dev/iov entry to be set by the driver.

The PCI_IOV option creates character devices in /dev/iov for each PF
device driver that registers support for creating VFs.  By default the
character device is named after the PF device (e.g. /dev/iov/foo0).
This change adds a variant of pci_iov_attach() called pci_iov_attach_name()
that allows the name of the /dev/iov entry to be specified by the
driver.

To preserve the ABI, this version does not modify the existing
PCI_IOV_ATTACH kobj method as was done in HEAD.  Instead, a new
PCI_IOV_ATTACH_NAME method has been added that accepts the name as an
additional parameter.  The PCI bus driver now provides an implementation
of PCI_IOV_ATTACH_NAME.  A default implementation of PCI_IOV_ATTACH is
provided that calls PCI_IOV_ATTACH_NAME passing 'device_get_nameunit(dev)'
as the name.

Sponsored by:	Chelsio Communications

7 files changed, 65 insertions, 7 deletions

diff --git a/share/man/man9/Makefile b/share/man/man9/Makefile
index 58b35f6..251a0d9 100644
--- a/share/man/man9/Makefile
+++ b/share/man/man9/Makefile
@@ -1303,6 +1303,7 @@ MLINKS+=pci.9 pci_alloc_msi.9 \
 	pci.9 pci_get_vpd_ident.9 \
 	pci.9 pci_get_vpd_readonly.9 \
 	pci.9 pci_iov_attach.9 \
+	pci.9 pci_iov_attach_name.9 \
 	pci.9 pci_iov_detach.9 \
 	pci.9 pci_msi_count.9 \
 	pci.9 pci_msix_count.9 \
diff --git a/share/man/man9/pci.9 b/share/man/man9/pci.9
index a53f971..161f9aa 100644
--- a/share/man/man9/pci.9
+++ b/share/man/man9/pci.9
@@ -25,7 +25,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd June 24, 2016
+.Dd August 3, 2016
 .Dt PCI 9
 .Os
 .Sh NAME
@@ -50,6 +50,7 @@
 .Nm pci_get_vpd_ident ,
 .Nm pci_get_vpd_readonly ,
 .Nm pci_iov_attach ,
+.Nm pci_iov_attach_name ,
 .Nm pci_iov_detach ,
 .Nm pci_msi_count ,
 .Nm pci_msix_count ,
@@ -152,6 +153,14 @@
 .Ft int
 .Fn pci_iov_attach "device_t dev" "nvlist_t *pf_schema" "nvlist_t *vf_schema"
 .Ft int
+.Fo pci_iov_attach_name
+.Fa "device_t dev"
+.Fa "nvlist_t *pf_schema"
+.Fa "nvlist_t *vf_schema"
+.Fa "const char *fmt"
+.Fa "..."
+.Fc
+.Ft int
 .Fn pci_iov_detach "device_t dev"
 .Sh DESCRIPTION
 The
@@ -595,6 +604,20 @@ and is responsible for freeing them.
 The driver must never free the schemas itself.
 .Pp
 The
+.Fn pci_iov_attach_name
+function is a variant of
+.Fn pci_iov_attach
+that allows the name of the associated character device in
+.Pa /dev/iov
+to be specified by
+.Fa fmt .
+The
+.Fn pci_iov_attach
+function uses the name of
+.Fa dev
+as the device name.
+.Pp
+The
 .Fn pci_iov_detach
 function is used to advise the SR-IOV infrastructure that the driver for the
 given device is attempting to detach and that all SR-IOV resources for the
diff --git a/sys/dev/pci/pci.c b/sys/dev/pci/pci.c
index 784dd00..3a5a938 100644
--- a/sys/dev/pci/pci.c
+++ b/sys/dev/pci/pci.c
@@ -195,7 +195,7 @@ static device_method_t pci_methods[] = {
 	DEVMETHOD(pci_alloc_devinfo,	pci_alloc_devinfo_method),
 	DEVMETHOD(pci_child_added,	pci_child_added_method),
 #ifdef PCI_IOV
-	DEVMETHOD(pci_iov_attach,	pci_iov_attach_method),
+	DEVMETHOD(pci_iov_attach_name,	pci_iov_attach_method),
 	DEVMETHOD(pci_iov_detach,	pci_iov_detach_method),
 	DEVMETHOD(pci_create_iov_child,	pci_create_iov_child_method),
 #endif
diff --git a/sys/dev/pci/pci_if.m b/sys/dev/pci/pci_if.m
index 5f8415f..027e618 100644
--- a/sys/dev/pci/pci_if.m
+++ b/sys/dev/pci/pci_if.m
@@ -51,6 +51,14 @@ CODE {
 		device_printf(bus, "PCI_IOV not implemented on this bus.\n");
 		return (NULL);
 	}
+
+	static int
+	compat_iov_attach(device_t bus, device_t dev, struct nvlist *pf_schema,
+	    struct nvlist *vf_schema)
+	{
+		return (PCI_IOV_ATTACH_NAME(bus, dev, pf_schema, vf_schema,
+		    device_get_nameunit(dev)));
+	}
 };
 
 HEADER {
@@ -235,6 +243,14 @@ METHOD int iov_attach {
 	device_t	child;
 	struct nvlist	*pf_schema;
 	struct nvlist	*vf_schema;
+} DEFAULT compat_iov_attach;
+
+METHOD int iov_attach_name {
+	device_t	dev;
+	device_t	child;
+	struct nvlist	*pf_schema;
+	struct nvlist	*vf_schema;
+	const char	*name;
 };
 
 METHOD int iov_detach {
diff --git a/sys/dev/pci/pci_iov.c b/sys/dev/pci/pci_iov.c
index bba99f6..19e51df 100644
--- a/sys/dev/pci/pci_iov.c
+++ b/sys/dev/pci/pci_iov.c
@@ -98,8 +98,22 @@ static nvlist_t	*pci_iov_get_pf_subsystem_schema(void);
 static nvlist_t	*pci_iov_get_vf_subsystem_schema(void);
 
 int
+pci_iov_attach_name(device_t dev, struct nvlist *pf_schema,
+    struct nvlist *vf_schema, const char *fmt, ...)
+{
+	char buf[NAME_MAX + 1];
+	va_list ap;
+
+	va_start(ap, fmt);
+	vsnprintf(buf, sizeof(buf), fmt, ap);
+	va_end(ap);
+	return (PCI_IOV_ATTACH_NAME(device_get_parent(dev), dev, pf_schema,
+	    vf_schema, buf));
+}
+
+int
 pci_iov_attach_method(device_t bus, device_t dev, nvlist_t *pf_schema,
-    nvlist_t *vf_schema)
+    nvlist_t *vf_schema, const char *name)
 {
 	device_t pcib;
 	struct pci_devinfo *dinfo;
@@ -149,7 +163,7 @@ pci_iov_attach_method(device_t bus, device_t dev, nvlist_t *pf_schema,
 	iov->iov_schema = schema;
 
 	iov->iov_cdev = make_dev(&iov_cdevsw, device_get_unit(dev),
-	    UID_ROOT, GID_WHEEL, 0600, "iov/%s", device_get_nameunit(dev));
+	    UID_ROOT, GID_WHEEL, 0600, "iov/%s", name);
 
 	if (iov->iov_cdev == NULL) {
 		error = ENOMEM;
diff --git a/sys/dev/pci/pci_iov.h b/sys/dev/pci/pci_iov.h
index fd2f8fb..09a182d 100644
--- a/sys/dev/pci/pci_iov.h
+++ b/sys/dev/pci/pci_iov.h
@@ -33,11 +33,14 @@
 
 struct nvlist;
 
+int	pci_iov_attach_name(device_t dev, struct nvlist *pf_schema,
+	    struct nvlist *vf_schema, const char *fmt, ...) __printflike(4, 5);
+
 static __inline int
 pci_iov_attach(device_t dev, struct nvlist *pf_schema, struct nvlist *vf_schema)
 {
-	return (PCI_IOV_ATTACH(device_get_parent(dev), dev, pf_schema,
-	    vf_schema));
+	return (PCI_IOV_ATTACH_NAME(device_get_parent(dev), dev, pf_schema,
+	    vf_schema, device_get_nameunit(dev)));
 }
 
 static __inline int
diff --git a/sys/dev/pci/pci_private.h b/sys/dev/pci/pci_private.h
index a9958ca..b0f1481 100644
--- a/sys/dev/pci/pci_private.h
+++ b/sys/dev/pci/pci_private.h
@@ -158,7 +158,8 @@ struct resource *pci_alloc_multi_resource(device_t dev, device_t child,
 		    rman_res_t count, u_long num, u_int flags);
 
 int		pci_iov_attach_method(device_t bus, device_t dev,
-		    struct nvlist *pf_schema, struct nvlist *vf_schema);
+		    struct nvlist *pf_schema, struct nvlist *vf_schema,
+		    const char *name);
 int		pci_iov_detach_method(device_t bus, device_t dev);
 
 device_t	pci_create_iov_child_method(device_t bus, device_t pf,