xref: /onnv-gate/usr/src/uts/sun/io/dada/impl/dcd_transport.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright (c) 1996,1999-2000 by Sun Microsystems, Inc.
24*0Sstevel@tonic-gate  * All rights reserved.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate /*
30*0Sstevel@tonic-gate  * Main Transport Routine for DADA.
31*0Sstevel@tonic-gate  *
32*0Sstevel@tonic-gate  */
33*0Sstevel@tonic-gate 
34*0Sstevel@tonic-gate #include <sys/dada/dada.h>
35*0Sstevel@tonic-gate #include <sys/thread.h>
36*0Sstevel@tonic-gate 
37*0Sstevel@tonic-gate 
38*0Sstevel@tonic-gate #define	A_TO_TRAN(ap)	((ap)->a_hba_tran)
39*0Sstevel@tonic-gate #define	P_TO_TRAN(pkt) 	((pkt)->pkt_address.a_hba_tran)
40*0Sstevel@tonic-gate #define	P_TO_ADDR(pkt)	(&((pkt)->pkt_address))
41*0Sstevel@tonic-gate 
42*0Sstevel@tonic-gate 
43*0Sstevel@tonic-gate extern	kmutex_t	dcd_flag_nointr_mutex;
44*0Sstevel@tonic-gate extern	kcondvar_t	dcd_flag_nointr_cv;
45*0Sstevel@tonic-gate 
46*0Sstevel@tonic-gate static void
dcd_flag_nointr_comp(struct dcd_pkt * pkt)47*0Sstevel@tonic-gate dcd_flag_nointr_comp(struct dcd_pkt *pkt)
48*0Sstevel@tonic-gate {
49*0Sstevel@tonic-gate 
50*0Sstevel@tonic-gate 	mutex_enter(&dcd_flag_nointr_mutex);
51*0Sstevel@tonic-gate 
52*0Sstevel@tonic-gate 	pkt->pkt_comp = NULL;
53*0Sstevel@tonic-gate 
54*0Sstevel@tonic-gate 	/*
55*0Sstevel@tonic-gate 	 * We need cv_broadcast, because there can be more than
56*0Sstevel@tonic-gate 	 * one thread sleeping on the cv. We will wake all of them.
57*0Sstevel@tonic-gate 	 * The correct one will continue and the reset will again go to
58*0Sstevel@tonic-gate 	 * sleep.
59*0Sstevel@tonic-gate 	 */
60*0Sstevel@tonic-gate 	cv_broadcast(&dcd_flag_nointr_cv);
61*0Sstevel@tonic-gate 	mutex_exit(&dcd_flag_nointr_mutex);
62*0Sstevel@tonic-gate }
63*0Sstevel@tonic-gate 
64*0Sstevel@tonic-gate 
65*0Sstevel@tonic-gate int
dcd_transport(struct dcd_pkt * pkt)66*0Sstevel@tonic-gate dcd_transport(struct dcd_pkt *pkt)
67*0Sstevel@tonic-gate {
68*0Sstevel@tonic-gate 
69*0Sstevel@tonic-gate 	struct dcd_address *ap = P_TO_ADDR(pkt);
70*0Sstevel@tonic-gate 	extern int do_polled_io;
71*0Sstevel@tonic-gate 	int rval;
72*0Sstevel@tonic-gate 
73*0Sstevel@tonic-gate 	/*
74*0Sstevel@tonic-gate 	 * Check if we are required to do polled I/O. We can
75*0Sstevel@tonic-gate 	 * get dcd_pkts that don't have the FLAG_NOINTR bit
76*0Sstevel@tonic-gate 	 * set in the pkt_flags. When do_polled_io is set
77*0Sstevel@tonic-gate 	 * we will probably be at a high IPL and not get any
78*0Sstevel@tonic-gate 	 * command completion interrupts. We force polled I/Os
79*0Sstevel@tonic-gate 	 * for such packets and do a callback of the completion
80*0Sstevel@tonic-gate 	 * routine ourselves.
81*0Sstevel@tonic-gate 	 */
82*0Sstevel@tonic-gate 	if (!do_polled_io && ((pkt->pkt_flags & FLAG_NOINTR) == 0)) {
83*0Sstevel@tonic-gate 		return ((*A_TO_TRAN(ap)->tran_start)(ap, pkt));
84*0Sstevel@tonic-gate 	} else if ((curthread->t_flag & T_INTR_THREAD) || (do_polled_io) ||
85*0Sstevel@tonic-gate 			(pkt->pkt_flags & FLAG_FORCENOINTR)) {
86*0Sstevel@tonic-gate 
87*0Sstevel@tonic-gate 		if (pkt->pkt_flags & FLAG_FORCENOINTR) {
88*0Sstevel@tonic-gate 			/*
89*0Sstevel@tonic-gate 			 * FLAG_FORCENOINTR means we do not want to rely on
90*0Sstevel@tonic-gate 			 * device interrupts. Set the FLAG_NOINTR
91*0Sstevel@tonic-gate 			 * so the command gets completed in polled mode.
92*0Sstevel@tonic-gate 			 */
93*0Sstevel@tonic-gate 			pkt->pkt_flags &= ~FLAG_FORCENOINTR;
94*0Sstevel@tonic-gate 			pkt->pkt_flags |= FLAG_NOINTR;
95*0Sstevel@tonic-gate 		}
96*0Sstevel@tonic-gate 
97*0Sstevel@tonic-gate 		/*
98*0Sstevel@tonic-gate 		 * If its an interrupt thread or we already have the
99*0Sstevel@tonic-gate 		 * the FLAG_NOINTR flag set, we go ahead and call the
100*0Sstevel@tonic-gate 		 * the hba's start routine directly. We force polling
101*0Sstevel@tonic-gate 		 * only if we have do_polled_io set and FLAG_NOINTR
102*0Sstevel@tonic-gate 		 * not set.
103*0Sstevel@tonic-gate 		 */
104*0Sstevel@tonic-gate 		if (!do_polled_io || (pkt->pkt_flags & FLAG_NOINTR)) {
105*0Sstevel@tonic-gate 			return ((*A_TO_TRAN(ap)->tran_start)(ap, pkt));
106*0Sstevel@tonic-gate 		} else {
107*0Sstevel@tonic-gate 			uint_t	savef;
108*0Sstevel@tonic-gate 			void	(*savec)();
109*0Sstevel@tonic-gate 			/*
110*0Sstevel@tonic-gate 			 * save the completion routine and pkt_flags
111*0Sstevel@tonic-gate 			 */
112*0Sstevel@tonic-gate 			savef = pkt->pkt_flags;
113*0Sstevel@tonic-gate 			savec = pkt->pkt_comp;
114*0Sstevel@tonic-gate 			pkt->pkt_flags |= FLAG_NOINTR;
115*0Sstevel@tonic-gate 			pkt->pkt_comp = 0;
116*0Sstevel@tonic-gate 
117*0Sstevel@tonic-gate 			rval = (*A_TO_TRAN(ap)->tran_start)(ap, pkt);
118*0Sstevel@tonic-gate 
119*0Sstevel@tonic-gate 			/*
120*0Sstevel@tonic-gate 			 * Restore the pkt_completion routine
121*0Sstevel@tonic-gate 			 * and pkt flags and call the completion
122*0Sstevel@tonic-gate 			 * routine.
123*0Sstevel@tonic-gate 			 */
124*0Sstevel@tonic-gate 			pkt->pkt_comp = savec;
125*0Sstevel@tonic-gate 			pkt->pkt_flags = savef;
126*0Sstevel@tonic-gate 			(*pkt->pkt_comp)(pkt);
127*0Sstevel@tonic-gate 			return (rval);
128*0Sstevel@tonic-gate 		}
129*0Sstevel@tonic-gate 	} else {
130*0Sstevel@tonic-gate 		uint_t	savef;
131*0Sstevel@tonic-gate 		void	(*savec)();
132*0Sstevel@tonic-gate 		int	status;
133*0Sstevel@tonic-gate 
134*0Sstevel@tonic-gate 		savef = pkt->pkt_flags;
135*0Sstevel@tonic-gate 		savec = pkt->pkt_comp;
136*0Sstevel@tonic-gate 
137*0Sstevel@tonic-gate 		pkt->pkt_comp = dcd_flag_nointr_comp;
138*0Sstevel@tonic-gate 		pkt->pkt_flags &= ~FLAG_NOINTR;
139*0Sstevel@tonic-gate 		pkt->pkt_flags |= FLAG_IMMEDIATE_CB;
140*0Sstevel@tonic-gate 
141*0Sstevel@tonic-gate 		if ((status = (*A_TO_TRAN(ap)->tran_start)(ap, pkt)) ==
142*0Sstevel@tonic-gate 			TRAN_ACCEPT) {
143*0Sstevel@tonic-gate 			mutex_enter(& dcd_flag_nointr_mutex);
144*0Sstevel@tonic-gate 			while (pkt->pkt_comp != NULL) {
145*0Sstevel@tonic-gate 				cv_wait(&dcd_flag_nointr_cv,
146*0Sstevel@tonic-gate 					&dcd_flag_nointr_mutex);
147*0Sstevel@tonic-gate 			}
148*0Sstevel@tonic-gate 			mutex_exit(&dcd_flag_nointr_mutex);
149*0Sstevel@tonic-gate 		}
150*0Sstevel@tonic-gate 		pkt->pkt_flags = savef;
151*0Sstevel@tonic-gate 		pkt->pkt_comp = savec;
152*0Sstevel@tonic-gate 		return (status);
153*0Sstevel@tonic-gate 	}
154*0Sstevel@tonic-gate }
155