xref: /illumos-gate/usr/src/uts/common/io/mac/mac_hio.c (revision 6895f6f4d5c99fd997130635c4a4bff68554bb8e)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*
27  * MAC Hybrid I/O related code.
28  */
29 
30 #include <sys/types.h>
31 #include <sys/sdt.h>
32 #include <sys/mac.h>
33 #include <sys/mac_impl.h>
34 #include <sys/mac_client_impl.h>
35 #include <sys/mac_client_priv.h>
36 #include <sys/mac_soft_ring.h>
37 
38 
39 /*
40  * Return the number of shares supported by the specified MAC.
41  */
42 int
mac_share_capable(mac_handle_t mh)43 mac_share_capable(mac_handle_t mh)
44 {
45 	mac_impl_t *mip = (mac_impl_t *)mh;
46 
47 	return (mip->mi_share_capab.ms_snum);
48 }
49 
50 
51 /*
52  * Allocate a share to the specified MAC client. Invoked when
53  * mac_client_open() is invoked with MAC_OPEN_FLAGS_SHARES_DESIRED set.
54  */
55 void
i_mac_share_alloc(mac_client_impl_t * mcip)56 i_mac_share_alloc(mac_client_impl_t *mcip)
57 {
58 	mac_impl_t *mip = mcip->mci_mip;
59 	int rv;
60 
61 	i_mac_perim_enter(mip);
62 
63 	ASSERT(mcip->mci_share == 0);
64 
65 	if (mac_share_capable((mac_handle_t)mcip->mci_mip) == 0) {
66 		DTRACE_PROBE1(i__mac__share__alloc__not__sup,
67 		    mac_client_impl_t *, mcip);
68 		i_mac_perim_exit(mip);
69 		return;
70 	}
71 
72 	rv = mip->mi_share_capab.ms_salloc(mip->mi_share_capab.ms_handle,
73 	    &mcip->mci_share);
74 	DTRACE_PROBE3(i__mac__share__alloc, mac_client_impl_t *, mcip,
75 	    int, rv, mac_share_handle_t, mcip->mci_share);
76 
77 	mcip->mci_state_flags &= ~MCIS_SHARE_BOUND;
78 
79 	i_mac_perim_exit(mip);
80 }
81 
82 
83 /*
84  * Free a share previously allocated through i_mac_share_alloc().
85  * Safely handles the case when no shares were allocated to the MAC client.
86  */
87 void
i_mac_share_free(mac_client_impl_t * mcip)88 i_mac_share_free(mac_client_impl_t *mcip)
89 {
90 	mac_impl_t *mip = mcip->mci_mip;
91 
92 	i_mac_perim_enter(mip);
93 
94 	/* MAC clients are required to unbind they shares before freeing them */
95 	ASSERT((mcip->mci_state_flags & MCIS_SHARE_BOUND) == 0);
96 
97 	if (mcip->mci_share == 0) {
98 		i_mac_perim_exit(mip);
99 		return;
100 	}
101 
102 	mip->mi_share_capab.ms_sfree(mcip->mci_share);
103 	i_mac_perim_exit(mip);
104 }
105 
106 
107 /*
108  * Bind a share. After this operation the rings that were associated
109  * with the MAC client are mapped directly into the corresponding
110  * guest domain.
111  */
112 int
mac_share_bind(mac_client_handle_t mch,uint64_t cookie,uint64_t * rcookie)113 mac_share_bind(mac_client_handle_t mch, uint64_t cookie, uint64_t *rcookie)
114 {
115 	mac_client_impl_t *mcip = (mac_client_impl_t *)mch;
116 	mac_impl_t *mip = mcip->mci_mip;
117 	int rv;
118 
119 	i_mac_perim_enter(mip);
120 
121 	if (mcip->mci_share == 0) {
122 		i_mac_perim_exit(mip);
123 		return (ENOTSUP);
124 	}
125 
126 	ASSERT((mcip->mci_state_flags & MCIS_SHARE_BOUND) == 0);
127 
128 	/*
129 	 * Temporarly suspend the TX traffic for that client to make sure
130 	 * there are no in flight packets through a transmit ring
131 	 * which is being bound to another domain.
132 	 */
133 	mac_tx_client_quiesce(mch);
134 
135 	/*
136 	 * For the receive path, no traffic will be sent up through
137 	 * the rings to the IO domain. For TX, we need to ensure
138 	 * that traffic sent by the MAC client are sent through
139 	 * the default ring.
140 	 *
141 	 * For the transmit path we ensure that packets are sent through the
142 	 * default ring if the share of the MAC client is bound, see MAC_TX().
143 	 */
144 
145 	rv = mip->mi_share_capab.ms_sbind(mcip->mci_share, cookie, rcookie);
146 	if (rv == 0)
147 		mcip->mci_state_flags |= MCIS_SHARE_BOUND;
148 
149 	/*
150 	 * Resume transmit traffic for the MAC client.
151 	 */
152 	mac_tx_client_restart(mch);
153 
154 	i_mac_perim_exit(mip);
155 
156 	return (rv);
157 }
158 
159 
160 /*
161  * Unbind a share.
162  */
163 void
mac_share_unbind(mac_client_handle_t mch)164 mac_share_unbind(mac_client_handle_t mch)
165 {
166 	mac_client_impl_t *mcip = (mac_client_impl_t *)mch;
167 	mac_impl_t *mip = mcip->mci_mip;
168 
169 	i_mac_perim_enter(mip);
170 
171 	if (mcip->mci_share == 0) {
172 		i_mac_perim_exit(mip);
173 		return;
174 	}
175 
176 	mip->mi_share_capab.ms_sunbind(mcip->mci_share);
177 
178 	mcip->mci_state_flags &= ~MCIS_SHARE_BOUND;
179 
180 	/*
181 	 * If the link state changed while the share was bound, the
182 	 * soft rings fanout associated with the client would have not
183 	 * been updated by mac_fanout_recompute(). Do the check here
184 	 * now that the share has been unbound.
185 	 */
186 	mac_fanout_recompute_client(mcip, NULL);
187 
188 	i_mac_perim_exit(mip);
189 }
190