interrupt.S revision 108379
1/*-
2 * Copyright (c) 2002 Jake Burkholder.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: head/sys/sparc64/sparc64/interrupt.S 108379 2002-12-29 00:23:48Z jake $
27 */
28
29#include <machine/asi.h>
30#include <machine/asmacros.h>
31#include <machine/ktr.h>
32#include <machine/pstate.h>
33
34#include "assym.s"
35
36/*
37 * Handle a vectored interrupt.
38 *
39 * This is either a data bearing mondo vector interrupt, or a cross trap
40 * request from another cpu.  In either case the hardware supplies an
41 * interrupt packet, in the form of 3 data words which are read from internal
42 * registers.  A data bearing mondo vector packet consists of an interrupt
43 * number in the first data word, and zero in 2nd and 3rd.  We use the
44 * interrupt number to find the function, argument and priority from the
45 * intr_vector table, allocate and fill in an intr_request from the per-cpu
46 * free list, link it onto the per-cpu active list and finally post a softint
47 * at the desired priority.  Cross trap requests come in 2 forms, direct
48 * and queued.  Direct requests are distinguished by the first data word
49 * being zero.  The 2nd data word carries a function to call and the 3rd
50 * an argument to pass.  The function is jumped to directly.  It executes
51 * in nucleus context on interrupt globals and with all interrupts disabled,
52 * therefore it must be fast, and the things that it can do are limited.
53 * Queued cross trap requests are handled much like mondo vectors, except
54 * that the function, argument and priority are contained in the interrupt
55 * packet itself.  They are distinguished by the upper 4 bits of the data
56 * word being non-zero, which specifies the priority of the softint to
57 * deliver.
58 *
59 * Register usage:
60 *	%g1 - pointer to intr_request
61 *	%g2 - pointer to intr_vector, temp once required data is loaded
62 *	%g3 - interrupt number for mondo vectors, unused otherwise
63 *	%g4 - function, from the interrupt packet for cross traps, or
64 *	      loaded from the interrupt registers for mondo vecors
65 *	%g5 - argument, as above for %g4
66 *	%g6 - softint priority
67 */
68ENTRY(intr_vector)
69	/*
70	 * Load the interrupt packet from the hardware.
71	 */
72	wr	%g0, ASI_SDB_INTR_R, %asi
73	ldxa	[%g0 + AA_SDB_INTR_D0] %asi, %g3
74	ldxa	[%g0 + AA_SDB_INTR_D1] %asi, %g4
75	ldxa	[%g0 + AA_SDB_INTR_D2] %asi, %g5
76	stxa	%g0, [%g0] ASI_INTR_RECEIVE
77	membar	#Sync
78
79	/*
80	 * If the first data word is zero this is a direct cross trap request.
81	 * The 2nd word points to code to execute and the 3rd is an argument
82	 * to pass.  Jump to it.
83	 */
84	brnz,a,pt %g3, 1f
85	 nop
86	jmpl	%g4, %g0
87	 nop
88	/* NOTREACHED */
89
90	/*
91	 * If the high 4 bits of the 1st data word are non-zero, this is a
92	 * queued cross trap request to be delivered as a softint.  The high
93	 * 4 bits of the 1st data word specify a priority, and the 2nd and
94	 * 3rd a function and argument.
95	 */
961:	srlx	%g3, 60, %g6
97	brnz,a,pn %g6, 2f
98	 clr	%g3
99
100	/*
101	 * Find the function, argument and desired priority from the
102	 * intr_vector table.
103	 */
104	SET(intr_vectors, %g4, %g2)
105	sllx	%g3, IV_SHIFT, %g4
106	add	%g2, %g4, %g2
107
108	ldx	[%g2 + IV_FUNC], %g4
109	ldx	[%g2 + IV_ARG], %g5
110	lduw	[%g2 + IV_PRI], %g6
111
112	/*
113	 * Get a intr_request from the free list.  There should always be one
114	 * unless we are getting an interrupt storm from stray interrupts, in
115	 * which case the we will deference a NULL pointer and panic.
116	 */
1172:	ldx	[PCPU(IRFREE)], %g1
118	ldx	[%g1 + IR_NEXT], %g2
119	stx	%g2, [PCPU(IRFREE)]
120
121	/*
122	 * Store the vector number, function, argument and priority.
123	 */
124	stw	%g3, [%g1 + IR_VEC]
125	stx	%g4, [%g1 + IR_FUNC]
126	stx	%g5, [%g1 + IR_ARG]
127	stw	%g6, [%g1 + IR_PRI]
128
129	/*
130	 * Link it onto the end of the active list.
131	 */
132	stx	%g0, [%g1 + IR_NEXT]
133	ldx	[PCPU(IRTAIL)], %g4
134	stx	%g1, [%g4]
135	add	%g1, IR_NEXT, %g1
136	stx	%g1, [PCPU(IRTAIL)]
137
138	/*
139	 * Trigger a softint at the level indicated by the priority.
140	 */
141	mov	1, %g1
142	sllx	%g1, %g6, %g1
143	wr	%g1, 0, %set_softint
144
145	/*
146	 * Done, retry the instruction.
147	 */
148	retry
149END(intr_vector)
150
151ENTRY(intr_fast)
152	save	%sp, -CCFSZ, %sp
153
1541:	ldx	[PCPU(IRHEAD)], %l0
155	brnz,a,pt %l0, 2f
156	 nop
157
158	ret
159	 restore
160
1612:	wrpr	%g0, PSTATE_NORMAL, %pstate
162
163	ldx	[%l0 + IR_NEXT], %l1
164	brnz,pt	%l1, 3f
165	 stx	%l1, [PCPU(IRHEAD)]
166	PCPU_ADDR(IRHEAD, %l1)
167	stx	%l1, [PCPU(IRTAIL)]
168
1693:	ldx	[%l0 + IR_FUNC], %o0
170	ldx	[%l0 + IR_ARG], %o1
171	ldx	[%l0 + IR_VEC], %o2
172
173	ldx	[PCPU(IRFREE)], %l1
174	stx	%l1, [%l0 + IR_NEXT]
175	stx	%l0, [PCPU(IRFREE)]
176
177	wrpr	%g0, PSTATE_KERNEL, %pstate
178
179	call	%o0
180	 mov	%o1, %o0
181	ba,a	%xcc, 1b
182	 nop
183END(intr_fast)
184