1 /* $NetBSD: ipi.c,v 1.30 2019/12/01 15:34:46 ad Exp $ */
2
3 /*-
4 * Copyright (c) 2000, 2008, 2009, 2019 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by RedBack Networks Inc.
9 *
10 * Author: Bill Sommerfeld
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
32 */
33
34 #include <sys/cdefs.h>
35 __KERNEL_RCSID(0, "$NetBSD: ipi.c,v 1.30 2019/12/01 15:34:46 ad Exp $");
36
37 #include "opt_mtrr.h"
38
39 #include <sys/param.h>
40 #include <sys/device.h>
41 #include <sys/systm.h>
42 #include <sys/atomic.h>
43 #include <sys/intr.h>
44 #include <sys/ipi.h>
45 #include <sys/cpu.h>
46 #include <sys/xcall.h>
47
48 #ifdef MULTIPROCESSOR
49
50 #include <machine/cpufunc.h>
51 #include <machine/cpuvar.h>
52 #include <machine/i82093var.h>
53 #include <machine/i82489reg.h>
54 #include <machine/i82489var.h>
55 #include <machine/mtrr.h>
56 #include <machine/gdt.h>
57
58 #include "acpica.h"
59
60 #include <x86/fpu.h>
61
62 static void x86_ipi_ast(struct cpu_info *);
63 static void x86_ipi_halt(struct cpu_info *);
64 static void x86_ipi_kpreempt(struct cpu_info *);
65 static void x86_ipi_xcall(struct cpu_info *);
66 static void x86_ipi_generic(struct cpu_info *);
67
68 #ifdef MTRR
69 static void x86_ipi_reload_mtrr(struct cpu_info *);
70 #else
71 #define x86_ipi_reload_mtrr NULL
72 #endif
73
74 #if NACPICA > 0
75 void acpi_cpu_sleep(struct cpu_info *);
76 #else
77 #define acpi_cpu_sleep NULL
78 #endif
79
80 static void x86_ipi_synch_fpu(struct cpu_info *);
81
82 void (* const ipifunc[X86_NIPI])(struct cpu_info *) =
83 {
84 x86_ipi_halt, /* X86_IPI_HALT */
85 x86_ipi_ast, /* X86_IPI_AST */
86 x86_ipi_generic, /* X86_IPI_GENERIC */
87 x86_ipi_synch_fpu, /* X86_IPI_SYNCH_FPU */
88 x86_ipi_reload_mtrr, /* X86_IPI_MTRR */
89 NULL, /* X86_IPI_GDT */
90 x86_ipi_xcall, /* X86_IPI_XCALL */
91 acpi_cpu_sleep, /* X86_IPI_ACPI_CPU_SLEEP */
92 x86_ipi_kpreempt /* X86_IPI_KPREEMPT */
93 };
94
95 /*
96 * x86 IPI interface.
97 */
98
99 int
x86_send_ipi(struct cpu_info * ci,int ipimask)100 x86_send_ipi(struct cpu_info *ci, int ipimask)
101 {
102 uint32_t o, n;
103 int ret = 0;
104
105 /* Don't send IPI to CPU which isn't (yet) running. */
106 if (__predict_false((ci->ci_flags & CPUF_RUNNING) == 0))
107 return ENOENT;
108
109 /* Set in new IPI bit, and capture previous state. */
110 for (o = 0;; o = n) {
111 n = atomic_cas_32(&ci->ci_ipis, o, o | ipimask);
112 if (__predict_true(o == n)) {
113 break;
114 }
115 }
116
117 /* If no IPI already pending, send one. */
118 if (o == 0) {
119 ret = x86_ipi(LAPIC_IPI_VECTOR, ci->ci_cpuid, LAPIC_DLMODE_FIXED);
120 if (ret != 0) {
121 printf("ipi of %x from %s to %s failed\n",
122 ipimask,
123 device_xname(curcpu()->ci_dev),
124 device_xname(ci->ci_dev));
125 }
126 }
127
128 return ret;
129 }
130
131 void
x86_broadcast_ipi(int ipimask)132 x86_broadcast_ipi(int ipimask)
133 {
134 struct cpu_info *ci, *self = curcpu();
135 int count = 0;
136 CPU_INFO_ITERATOR cii;
137
138 for (CPU_INFO_FOREACH(cii, ci)) {
139 if (ci == self)
140 continue;
141 if ((ci->ci_flags & CPUF_RUNNING) == 0)
142 continue;
143 atomic_or_32(&ci->ci_ipis, ipimask);
144 count++;
145 }
146 if (!count)
147 return;
148
149 x86_ipi(LAPIC_IPI_VECTOR, LAPIC_DEST_ALLEXCL, LAPIC_DLMODE_FIXED);
150 }
151
152 void
x86_ipi_handler(void)153 x86_ipi_handler(void)
154 {
155 struct cpu_info *ci = curcpu();
156 uint32_t pending;
157 int bit;
158
159 pending = atomic_swap_32(&ci->ci_ipis, 0);
160
161 KDASSERT((pending >> X86_NIPI) == 0);
162 while ((bit = ffs(pending)) != 0) {
163 bit--;
164 pending &= ~(1 << bit);
165 ci->ci_ipi_events[bit].ev_count++;
166 (*ipifunc[bit])(ci);
167 }
168 }
169
170 /*
171 * Common x86 IPI handlers.
172 */
173
174 static void
x86_ipi_halt(struct cpu_info * ci)175 x86_ipi_halt(struct cpu_info *ci)
176 {
177
178 x86_disable_intr();
179 atomic_and_32(&ci->ci_flags, ~CPUF_RUNNING);
180
181 for (;;) {
182 x86_hlt();
183 }
184 }
185
186 static void
x86_ipi_synch_fpu(struct cpu_info * ci)187 x86_ipi_synch_fpu(struct cpu_info *ci)
188 {
189
190 panic("%s: impossible", __func__);
191 }
192
193 #ifdef MTRR
194 static void
x86_ipi_reload_mtrr(struct cpu_info * ci)195 x86_ipi_reload_mtrr(struct cpu_info *ci)
196 {
197
198 if (mtrr_funcs != NULL) {
199 /*
200 * mtrr_reload_cpu() is a macro in mtrr.h which picks
201 * the appropriate function to use.
202 */
203 mtrr_reload_cpu(ci);
204 }
205 }
206 #endif
207
208 static void
x86_ipi_kpreempt(struct cpu_info * ci)209 x86_ipi_kpreempt(struct cpu_info *ci)
210 {
211
212 softint_trigger(1 << SIR_PREEMPT);
213 }
214
215 static void
x86_ipi_ast(struct cpu_info * ci)216 x86_ipi_ast(struct cpu_info *ci)
217 {
218
219 aston(ci->ci_onproc);
220 }
221
222 /*
223 * MD support for xcall(9) interface.
224 */
225
226 static void
x86_ipi_xcall(struct cpu_info * ci)227 x86_ipi_xcall(struct cpu_info *ci)
228 {
229 xc_ipi_handler();
230 }
231
232 static void
x86_ipi_generic(struct cpu_info * ci)233 x86_ipi_generic(struct cpu_info *ci)
234 {
235 ipi_cpu_handler();
236 }
237
238 void
xc_send_ipi(struct cpu_info * ci)239 xc_send_ipi(struct cpu_info *ci)
240 {
241
242 KASSERT(kpreempt_disabled());
243 KASSERT(curcpu() != ci);
244
245 if (ci) {
246 /* Unicast: remote CPU. */
247 x86_send_ipi(ci, X86_IPI_XCALL);
248 } else {
249 /* Broadcast: all, but local CPU (caller will handle it). */
250 x86_broadcast_ipi(X86_IPI_XCALL);
251 }
252 }
253
254 void
cpu_ipi(struct cpu_info * ci)255 cpu_ipi(struct cpu_info *ci)
256 {
257 KASSERT(kpreempt_disabled());
258 KASSERT(curcpu() != ci);
259
260 if (ci) {
261 /* Unicast: remote CPU. */
262 x86_send_ipi(ci, X86_IPI_GENERIC);
263 } else {
264 /* Broadcast: all, but local CPU (caller will handle it). */
265 x86_broadcast_ipi(X86_IPI_GENERIC);
266 }
267 }
268
269 #else
270
271 int
x86_send_ipi(struct cpu_info * ci,int ipimask)272 x86_send_ipi(struct cpu_info *ci, int ipimask)
273 {
274
275 return 0;
276 }
277
278 void
x86_broadcast_ipi(int ipimask)279 x86_broadcast_ipi(int ipimask)
280 {
281
282 }
283
284 void
cpu_ipi(struct cpu_info * ci)285 cpu_ipi(struct cpu_info *ci)
286 {
287 }
288
289 #endif
290