Add a NetBSD-compatible mii_attach(), which is intended to eventually

replace mii_phy_probe() altogether. Compared to the latter the advantages
of mii_attach() are:
- intended to be called multiple times in order to attach PHYs in multiple
  passes (f.e. in order to only use sub-ranges of the 0 to MII_NPHY - 1
  range)
- being able to pass along the capability mask from the NIC to the PHY
  drivers
- being able to specify at which address (phyloc) to probe for a PHY
  (instead of always probing at all addresses from 0 to MII_NPHY - 1)
- being able to specify which PHY instance (offloc) to attach
- being able to pass along MIIF_* flags from the NIC to the PHY drivers
  (f.e. as required to indicated to the PHY drivers that flow control is
  supported by the NIC driver, which actually is the motivation for this
  change).

While at it, I used the opportunity to get rid of some hacks in mii(4)
like miibus_probe() generally doing work besides sheer probing and the
"EVIL HACK" (which will vanish entirely along with mii_phy_probe()) by
passing the struct ifnet pointer via an argument of mii_attach() as well
as to fix some resource leaks in mii(4) in case something fails.
Commits which will update the PHY drivers to honor the MII flags passed
down from the NIC drivers and take advantage of mii_attach() to get rid
of certain types of hacks in NIC and PHY drivers as well as a conversion
of the remaining uses of mii_phy_probe() will follow shortly.

Reviewed by:	jhb, yongari
Obtained from:	NetBSD (partially)

1 files changed, 212 insertions, 86 deletions

diff --git a/sys/dev/mii/mii.c b/sys/dev/mii/mii.c
index f19fcc2..263a18b 100644
--- a/sys/dev/mii/mii.c
+++ b/sys/dev/mii/mii.c
@@ -58,6 +58,8 @@ MODULE_VERSION(miibus, 1);
 #include "miibus_if.h"
 
 static int miibus_print_child(device_t dev, device_t child);
+static int miibus_read_ivar(device_t dev, device_t child, int which,
+    uintptr_t *result);
 static int miibus_child_location_str(device_t bus, device_t child, char *buf,
     size_t buflen);
 static int miibus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
@@ -77,6 +79,7 @@ static device_method_t miibus_methods[] = {
 
 	/* bus interface */
 	DEVMETHOD(bus_print_child,	miibus_print_child),
+	DEVMETHOD(bus_read_ivar,	miibus_read_ivar),
 	DEVMETHOD(bus_driver_added,	bus_generic_driver_added),
 	DEVMETHOD(bus_child_pnpinfo_str, miibus_child_pnpinfo_str),
 	DEVMETHOD(bus_child_location_str, miibus_child_location_str),
@@ -100,87 +103,52 @@ driver_t miibus_driver = {
 };
 
 struct miibus_ivars {
+	struct ifnet	*ifp;
 	ifm_change_cb_t	ifmedia_upd;
 	ifm_stat_cb_t	ifmedia_sts;
+	int		mii_flags;
 };
 
-/*
- * Helper function used by network interface drivers, attaches PHYs
- * to the network interface driver parent.
- */
 int
 miibus_probe(device_t dev)
 {
-	struct mii_attach_args	ma, *args;
-	struct mii_data		*mii;
-	device_t		child = NULL, parent;
-	int			bmsr, capmask = 0xFFFFFFFF;
-
-	mii = device_get_softc(dev);
-	parent = device_get_parent(dev);
-	LIST_INIT(&mii->mii_phys);
-
-	for (ma.mii_phyno = 0; ma.mii_phyno < MII_NPHY; ma.mii_phyno++) {
-		/*
-		 * Check to see if there is a PHY at this address.  Note,
-		 * many braindead PHYs report 0/0 in their ID registers,
-		 * so we test for media in the BMSR.
-	 	 */
-		bmsr = MIIBUS_READREG(parent, ma.mii_phyno, MII_BMSR);
-		if (bmsr == 0 || bmsr == 0xffff ||
-		    (bmsr & (BMSR_EXTSTAT | BMSR_MEDIAMASK)) == 0) {
-			/* Assume no PHY at this address. */
-			continue;
-		}
-
-		/*
-		 * Extract the IDs. Braindead PHYs will be handled by
-		 * the `ukphy' driver, as we have no ID information to
-		 * match on.
-	 	 */
-		ma.mii_id1 = MIIBUS_READREG(parent, ma.mii_phyno,
-		    MII_PHYIDR1);
-		ma.mii_id2 = MIIBUS_READREG(parent, ma.mii_phyno,
-		    MII_PHYIDR2);
-
-		ma.mii_data = mii;
-		ma.mii_capmask = capmask;
-
-		args = malloc(sizeof(struct mii_attach_args),
-		    M_DEVBUF, M_NOWAIT);
-		bcopy((char *)&ma, (char *)args, sizeof(ma));
-		child = device_add_child(dev, NULL, -1);
-		device_set_ivars(child, args);
-	}
-
-	if (child == NULL)
-		return (ENXIO);
 
 	device_set_desc(dev, "MII bus");
 
-	return (0);
+	return (BUS_PROBE_SPECIFIC);
 }
 
 int
 miibus_attach(device_t dev)
 {
 	struct miibus_ivars	*ivars;
+	struct mii_attach_args	*ma;
 	struct mii_data		*mii;
+	device_t		*children;
+	int			i, nchildren;
 
 	mii = device_get_softc(dev);
-	/*
-	 * Note that each NIC's softc must start with an ifnet pointer.
-	 * XXX: EVIL HACK!
-	 */
-	mii->mii_ifp = *(struct ifnet**)device_get_softc(device_get_parent(dev));
-	mii->mii_ifp->if_capabilities |= IFCAP_LINKSTATE;
-	mii->mii_ifp->if_capenable |= IFCAP_LINKSTATE;
+	nchildren = 0;
+	if (device_get_children(dev, &children, &nchildren) == 0) {
+		for (i = 0; i < nchildren; i++) {
+			ma = device_get_ivars(children[i]);
+			ma->mii_data = mii;
+		}
+		free(children, M_TEMP);
+	}
+	if (nchildren == 0) {
+		device_printf(dev, "cannot get children");
+		return (ENXIO);
+	}
 	ivars = device_get_ivars(dev);
 	ifmedia_init(&mii->mii_media, IFM_IMASK, ivars->ifmedia_upd,
 	    ivars->ifmedia_sts);
-	bus_generic_attach(dev);
+	mii->mii_ifp = ivars->ifp;
+	mii->mii_ifp->if_capabilities |= IFCAP_LINKSTATE;
+	mii->mii_ifp->if_capenable |= IFCAP_LINKSTATE;
+	LIST_INIT(&mii->mii_phys);
 
-	return (0);
+	return (bus_generic_attach(dev));
 }
 
 int
@@ -211,7 +179,28 @@ miibus_print_child(device_t dev, device_t child)
 }
 
 static int
-miibus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
+miibus_read_ivar(device_t dev, device_t child __unused, int which,
+    uintptr_t *result)
+{
+	struct miibus_ivars *ivars;
+
+	/*
+	 * NB: this uses the instance variables of the miibus rather than
+	 * its PHY children.
+	 */
+	ivars = device_get_ivars(dev);
+	switch (which) {
+	case MIIBUS_IVAR_FLAGS:
+		*result = ivars->mii_flags;
+		break;
+	default:
+		return (ENOENT);
+	}
+	return (0);
+}
+
+static int
+miibus_child_pnpinfo_str(device_t bus __unused, device_t child, char *buf,
     size_t buflen)
 {
 	struct mii_attach_args *ma;
@@ -224,7 +213,7 @@ miibus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
 }
 
 static int
-miibus_child_location_str(device_t bus, device_t child, char *buf,
+miibus_child_location_str(device_t bus __unused, device_t child, char *buf,
     size_t buflen)
 {
 	struct mii_attach_args *ma;
@@ -307,40 +296,177 @@ miibus_mediainit(device_t dev)
 	ifmedia_set(&mii->mii_media, media);
 }
 
+/*
+ * Helper function used by network interface drivers, attaches the miibus and
+ * the PHYs to the network interface driver parent.
+ */
 int
-mii_phy_probe(device_t dev, device_t *child, ifm_change_cb_t ifmedia_upd,
-    ifm_stat_cb_t ifmedia_sts)
+mii_attach(device_t dev, device_t *miibus, struct ifnet *ifp,
+    ifm_change_cb_t ifmedia_upd, ifm_stat_cb_t ifmedia_sts, int capmask,
+    int phyloc, int offloc, int flags)
 {
-	struct miibus_ivars	*ivars;
-	int			bmsr, i;
-
-	ivars = malloc(sizeof(*ivars), M_DEVBUF, M_NOWAIT);
-	if (ivars == NULL)
-		return (ENOMEM);
-	ivars->ifmedia_upd = ifmedia_upd;
-	ivars->ifmedia_sts = ifmedia_sts;
-	*child = device_add_child(dev, "miibus", -1);
-	device_set_ivars(*child, ivars);
-
-	for (i = 0; i < MII_NPHY; i++) {
-		bmsr = MIIBUS_READREG(dev, i, MII_BMSR);
-                if (bmsr == 0 || bmsr == 0xffff ||
-                    (bmsr & (BMSR_EXTSTAT | BMSR_MEDIAMASK)) == 0) {
-                        /* Assume no PHY at this address. */
-                        continue;
-                } else
-			break;
+	struct miibus_ivars *ivars;
+	struct mii_attach_args ma, *args;
+	device_t *children, phy;
+	int bmsr, first, i, nchildren, offset, phymax, phymin, rv;
+
+	if (phyloc != MII_PHY_ANY && offloc != MII_OFFSET_ANY) {
+		printf("%s: phyloc and offloc specified", __func__);
+		return (EINVAL);
 	}
 
-	if (i == MII_NPHY) {
-		device_delete_child(dev, *child);
-		*child = NULL;
-		return (ENXIO);
+	if (offloc != MII_OFFSET_ANY && (offloc < 0 || offloc >= MII_NPHY)) {
+		printf("%s: ivalid offloc %d", __func__, offloc);
+		return (EINVAL);
+	}
+
+	if (phyloc == MII_PHY_ANY) {
+		phymin = 0;
+		phymax = MII_NPHY - 1;
+	} else {
+		if (phyloc < 0 || phyloc >= MII_NPHY) {
+			printf("%s: ivalid phyloc %d", __func__, phyloc);
+			return (EINVAL);
+		}
+		phymin = phymax = phyloc;
 	}
 
-	bus_generic_attach(dev);
+	first = 0;
+	if (*miibus == NULL) {
+		first = 1;
+		ivars = malloc(sizeof(*ivars), M_DEVBUF, M_NOWAIT);
+		if (ivars == NULL)
+			return (ENOMEM);
+		ivars->ifp = ifp;
+		ivars->ifmedia_upd = ifmedia_upd;
+		ivars->ifmedia_sts = ifmedia_sts;
+		ivars->mii_flags = flags;
+		*miibus = device_add_child(dev, "miibus", -1);
+		if (*miibus == NULL) {
+			rv = ENXIO;
+			goto fail;
+		}
+		device_set_ivars(*miibus, ivars);
+	} else {
+		ivars = device_get_ivars(*miibus);
+		if (ivars->ifp != ifp || ivars->ifmedia_upd != ifmedia_upd ||
+		    ivars->ifmedia_sts != ifmedia_sts ||
+		    ivars->mii_flags != flags) {
+			printf("%s: non-matching invariant", __func__);
+			return (EINVAL);
+		}
+		/*
+		 * Assignment of the attach arguments mii_data for the first
+		 * pass is done in miibus_attach(), i.e. once the miibus softc
+		 * has been allocated.
+		 */
+		ma.mii_data = device_get_softc(*miibus);
+	} 
+
+	ma.mii_capmask = capmask;
+
+	phy = NULL;
+	offset = 0;
+	for (ma.mii_phyno = phymin; ma.mii_phyno <= phymax; ma.mii_phyno++) {
+		/*
+		 * Make sure we haven't already configured a PHY at this
+		 * address.  This allows mii_attach() to be called
+		 * multiple times.
+		 */
+		if (device_get_children(*miibus, &children, &nchildren) == 0) {
+			for (i = 0; i < nchildren; i++) {
+				args = device_get_ivars(children[i]);
+				if (args->mii_phyno == ma.mii_phyno) {
+					/*
+					 * Yes, there is already something
+					 * configured at this address.
+					 */
+					free(children, M_TEMP);
+					goto skip;
+				}
+			}
+			free(children, M_TEMP);
+		}
+
+		/*
+		 * Check to see if there is a PHY at this address.  Note,
+		 * many braindead PHYs report 0/0 in their ID registers,
+		 * so we test for media in the BMSR.
+	 	 */
+		bmsr = MIIBUS_READREG(dev, ma.mii_phyno, MII_BMSR);
+		if (bmsr == 0 || bmsr == 0xffff ||
+		    (bmsr & (BMSR_EXTSTAT | BMSR_MEDIAMASK)) == 0) {
+			/* Assume no PHY at this address. */
+			continue;
+		}
+
+		/*
+		 * There is a PHY at this address.  If we were given an
+		 * `offset' locator, skip this PHY if it doesn't match.
+		 */
+		if (offloc != MII_OFFSET_ANY && offloc != offset)
+			goto skip;
+
+		/*
+		 * Extract the IDs. Braindead PHYs will be handled by
+		 * the `ukphy' driver, as we have no ID information to
+		 * match on.
+	 	 */
+		ma.mii_id1 = MIIBUS_READREG(dev, ma.mii_phyno, MII_PHYIDR1);
+		ma.mii_id2 = MIIBUS_READREG(dev, ma.mii_phyno, MII_PHYIDR2);
+
+		args = malloc(sizeof(struct mii_attach_args), M_DEVBUF,
+		    M_NOWAIT);
+		if (args == NULL)
+			goto skip;
+		bcopy((char *)&ma, (char *)args, sizeof(ma));
+		phy = device_add_child(*miibus, NULL, -1);
+		if (phy == NULL) {
+			free(args, M_DEVBUF);
+			goto skip;
+		}
+		device_set_ivars(phy, args);
+ skip:
+		offset++;
+	}
+
+	if (first != 0) {
+		if (phy == NULL) {
+			rv = ENXIO;
+			goto fail;
+		}
+		rv = bus_generic_attach(dev);
+		if (rv != 0)
+			goto fail;
+	}
+	rv = bus_generic_attach(*miibus);
+	if (rv != 0)
+		goto fail;
 
 	return (0);
+
+ fail:
+	if (*miibus != NULL)
+		device_delete_child(dev, *miibus);
+	free(ivars, M_DEVBUF);
+	if (first != 0)
+		*miibus = NULL;
+	return (rv);
+}
+
+int
+mii_phy_probe(device_t dev, device_t *child, ifm_change_cb_t ifmedia_upd,
+    ifm_stat_cb_t ifmedia_sts)
+{
+	struct ifnet *ifp;
+
+	/*
+	 * Note that each NIC's softc must start with an ifnet pointer.
+	 * XXX: EVIL HACK!
+	 */
+	ifp = *(struct ifnet **)device_get_softc(dev);
+	return (mii_attach(dev, child, ifp, ifmedia_upd, ifmedia_sts,
+	    BMSR_DEFCAPMASK, MII_PHY_ANY, MII_OFFSET_ANY, 0));
 }
 
 /*