1 /* $NetBSD: ipifuncs.c,v 1.55 2022/04/09 23:42:56 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 1998, 1999, 2000, 2001 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #include <sys/cdefs.h> /* RCS ID & Copyright macro defns */
34
35 __KERNEL_RCSID(0, "$NetBSD: ipifuncs.c,v 1.55 2022/04/09 23:42:56 riastradh Exp $");
36
37 /*
38 * Interprocessor interrupt handlers.
39 */
40
41 #include <sys/param.h>
42 #include <sys/device.h>
43 #include <sys/proc.h>
44 #include <sys/systm.h>
45 #include <sys/reboot.h>
46 #include <sys/atomic.h>
47 #include <sys/cpu.h>
48 #include <sys/ipi.h>
49 #include <sys/intr.h>
50 #include <sys/xcall.h>
51 #include <sys/bitops.h>
52
53 #include <uvm/uvm_extern.h>
54
55 #include <machine/alpha_cpu.h>
56 #include <machine/alpha.h>
57 #include <machine/cpuvar.h>
58 #include <machine/rpb.h>
59 #include <machine/prom.h>
60
61 typedef void (*ipifunc_t)(struct cpu_info *, struct trapframe *);
62
63 static void alpha_ipi_halt(struct cpu_info *, struct trapframe *);
64 static void alpha_ipi_primary_cc(struct cpu_info *, struct trapframe *);
65 static void alpha_ipi_ast(struct cpu_info *, struct trapframe *);
66 static void alpha_ipi_pause(struct cpu_info *, struct trapframe *);
67 static void alpha_ipi_xcall(struct cpu_info *, struct trapframe *);
68 static void alpha_ipi_generic(struct cpu_info *, struct trapframe *);
69
70 const ipifunc_t ipifuncs[ALPHA_NIPIS] = {
71 [ilog2(ALPHA_IPI_HALT)] = alpha_ipi_halt,
72 [ilog2(ALPHA_IPI_PRIMARY_CC)] = alpha_ipi_primary_cc,
73 [ilog2(ALPHA_IPI_SHOOTDOWN)] = pmap_tlb_shootdown_ipi,
74 [ilog2(ALPHA_IPI_AST)] = alpha_ipi_ast,
75 [ilog2(ALPHA_IPI_PAUSE)] = alpha_ipi_pause,
76 [ilog2(ALPHA_IPI_XCALL)] = alpha_ipi_xcall,
77 [ilog2(ALPHA_IPI_GENERIC)] = alpha_ipi_generic
78 };
79
80 const char * const ipinames[ALPHA_NIPIS] = {
81 [ilog2(ALPHA_IPI_HALT)] = "halt ipi",
82 [ilog2(ALPHA_IPI_PRIMARY_CC)] = "primary cc ipi",
83 [ilog2(ALPHA_IPI_SHOOTDOWN)] = "shootdown ipi",
84 [ilog2(ALPHA_IPI_AST)] = "ast ipi",
85 [ilog2(ALPHA_IPI_PAUSE)] = "pause ipi",
86 [ilog2(ALPHA_IPI_XCALL)] = "xcall ipi",
87 [ilog2(ALPHA_IPI_GENERIC)] = "generic ipi",
88 };
89
90 /*
91 * Initialize IPI state for a CPU.
92 *
93 * Note: the cpu_info softc pointer must be valid.
94 */
95 void
alpha_ipi_init(struct cpu_info * ci)96 alpha_ipi_init(struct cpu_info *ci)
97 {
98 struct cpu_softc * const sc = ci->ci_softc;
99 const char * const xname = device_xname(sc->sc_dev);
100 int i;
101
102 evcnt_attach_dynamic(&sc->sc_evcnt_ipi, EVCNT_TYPE_INTR,
103 NULL, xname, "ipi");
104
105 for (i = 0; i < ALPHA_NIPIS; i++) {
106 evcnt_attach_dynamic(&sc->sc_evcnt_which_ipi[i],
107 EVCNT_TYPE_INTR, NULL, xname, ipinames[i]);
108 }
109 }
110
111 /*
112 * Process IPIs for a CPU.
113 */
114 void
alpha_ipi_process(struct cpu_info * ci,struct trapframe * framep)115 alpha_ipi_process(struct cpu_info *ci, struct trapframe *framep)
116 {
117 struct cpu_softc * const sc = ci->ci_softc;
118 u_long pending_ipis, bit;
119
120 #ifdef DIAGNOSTIC
121 if (sc == NULL) {
122 /* XXX panic? */
123 printf("WARNING: no softc for ID %lu\n", ci->ci_cpuid);
124 return;
125 }
126 #endif
127
128 while ((pending_ipis = atomic_swap_ulong(&ci->ci_ipis, 0)) != 0) {
129 /*
130 * Ensure everything prior to setting ci_ipis in
131 * alpha_send_ipi happens-before everything after
132 * reading ci_ipis here so we're not working on stale
133 * inputs.
134 */
135 membar_acquire();
136
137 sc->sc_evcnt_ipi.ev_count++;
138
139 for (bit = 0; bit < ALPHA_NIPIS; bit++) {
140 if (pending_ipis & (1UL << bit)) {
141 sc->sc_evcnt_which_ipi[bit].ev_count++;
142 (*ipifuncs[bit])(ci, framep);
143 }
144 }
145 }
146 }
147
148 /*
149 * Send an interprocessor interrupt.
150 */
151 void
alpha_send_ipi(u_long const cpu_id,u_long const ipimask)152 alpha_send_ipi(u_long const cpu_id, u_long const ipimask)
153 {
154
155 KASSERT(cpu_id < hwrpb->rpb_pcs_cnt);
156 KASSERT(cpu_info[cpu_id] != NULL);
157 KASSERT(cpus_running & (1UL << cpu_id));
158
159 /*
160 * Make sure all loads and stores prior to calling
161 * alpha_send_ipi() have completed before informing
162 * the CPU of the work we are asking it to do.
163 */
164 membar_release();
165 atomic_or_ulong(&cpu_info[cpu_id]->ci_ipis, ipimask);
166
167 /*
168 * Ensure that the store of ipimask completes before actually
169 * writing to the IPIR.
170 *
171 * Note: we use MB rather than WMB because how the IPIR
172 * is implemented is not architecturally specified, and
173 * WMB is only guaranteed to provide ordering for stores
174 * to regions of the same memory-likeness.
175 */
176 alpha_mb();
177 alpha_pal_wripir(cpu_id);
178 }
179
180 /*
181 * Broadcast an IPI to all but ourselves.
182 */
183 void
alpha_broadcast_ipi(u_long const ipimask)184 alpha_broadcast_ipi(u_long const ipimask)
185 {
186 struct cpu_info *ci;
187 CPU_INFO_ITERATOR cii;
188
189 const u_long cpu_id = cpu_number();
190 const u_long cpumask = cpus_running & ~(1UL << cpu_id);
191
192 for (CPU_INFO_FOREACH(cii, ci)) {
193 if ((cpumask & (1UL << ci->ci_cpuid)) == 0)
194 continue;
195 alpha_send_ipi(ci->ci_cpuid, ipimask);
196 }
197 }
198
199 /*
200 * Send an IPI to all in the list but ourselves.
201 */
202 void
alpha_multicast_ipi(u_long cpumask,u_long const ipimask)203 alpha_multicast_ipi(u_long cpumask, u_long const ipimask)
204 {
205 struct cpu_info *ci;
206 CPU_INFO_ITERATOR cii;
207
208 cpumask &= cpus_running;
209 cpumask &= ~(1UL << cpu_number());
210 if (cpumask == 0)
211 return;
212
213 for (CPU_INFO_FOREACH(cii, ci)) {
214 if ((cpumask & (1UL << ci->ci_cpuid)) == 0)
215 continue;
216 alpha_send_ipi(ci->ci_cpuid, ipimask);
217 }
218 }
219
220 static void
alpha_ipi_halt(struct cpu_info * const ci,struct trapframe * const framep __unused)221 alpha_ipi_halt(struct cpu_info * const ci,
222 struct trapframe * const framep __unused)
223 {
224 const u_long cpu_id = ci->ci_cpuid;
225 const u_long wait_mask = (1UL << cpu_id);
226
227 /* Disable interrupts. */
228 (void) splhigh();
229
230 if (cpu_id != hwrpb->rpb_primary_cpu_id) {
231 /*
232 * If we're not the primary, we just halt now.
233 */
234 cpu_halt();
235 }
236
237 /*
238 * We're the primary. We need to wait for all the other
239 * secondary CPUs to halt, then we can drop back to the
240 * console.
241 */
242 alpha_mb();
243 for (;;) {
244 alpha_mb();
245 if (cpus_running == wait_mask)
246 break;
247 delay(1000);
248 }
249
250 prom_halt(boothowto & RB_HALT);
251 /* NOTREACHED */
252 }
253
254 static void
alpha_ipi_primary_cc(struct cpu_info * const ci __unused,struct trapframe * const framep __unused)255 alpha_ipi_primary_cc(struct cpu_info * const ci __unused,
256 struct trapframe * const framep __unused)
257 {
258 int const s = splhigh();
259 cc_primary_cc();
260 splx(s);
261 }
262
263 static void
alpha_ipi_ast(struct cpu_info * const ci,struct trapframe * const framep __unused)264 alpha_ipi_ast(struct cpu_info * const ci,
265 struct trapframe * const framep __unused)
266 {
267
268 if (ci->ci_onproc != ci->ci_data.cpu_idlelwp)
269 aston(ci->ci_onproc);
270 }
271
272 static void
alpha_ipi_pause(struct cpu_info * const ci,struct trapframe * const framep)273 alpha_ipi_pause(struct cpu_info * const ci, struct trapframe * const framep)
274 {
275 const u_long cpumask = (1UL << ci->ci_cpuid);
276 int s;
277
278 s = splhigh();
279
280 /* Point debuggers at our trapframe for register state. */
281 ci->ci_db_regs = framep;
282 alpha_wmb();
283 atomic_or_ulong(&ci->ci_flags, CPUF_PAUSED);
284
285 /* Spin with interrupts disabled until we're resumed. */
286 do {
287 alpha_mb();
288 } while (cpus_paused & cpumask);
289
290 atomic_and_ulong(&ci->ci_flags, ~CPUF_PAUSED);
291 alpha_wmb();
292 ci->ci_db_regs = NULL;
293
294 splx(s);
295
296 /* Do a TBIA+IMB on the way out, in case things have changed. */
297 ALPHA_TBIA();
298 alpha_pal_imb();
299 }
300
301 /*
302 * MD support for xcall(9) interface.
303 */
304
305 static void
alpha_ipi_xcall(struct cpu_info * const ci __unused,struct trapframe * const framep __unused)306 alpha_ipi_xcall(struct cpu_info * const ci __unused,
307 struct trapframe * const framep __unused)
308 {
309 xc_ipi_handler();
310 }
311
312 void
xc_send_ipi(struct cpu_info * const ci)313 xc_send_ipi(struct cpu_info * const ci)
314 {
315 KASSERT(kpreempt_disabled());
316 KASSERT(curcpu() != ci);
317
318 if (ci) {
319 /* Unicast: remote CPU. */
320 alpha_send_ipi(ci->ci_cpuid, ALPHA_IPI_XCALL);
321 } else {
322 /* Broadcast: all, but local CPU (caller will handle it). */
323 alpha_broadcast_ipi(ALPHA_IPI_XCALL);
324 }
325 }
326
327 static void
alpha_ipi_generic(struct cpu_info * const ci __unused,struct trapframe * const framep __unused)328 alpha_ipi_generic(struct cpu_info * const ci __unused,
329 struct trapframe * const framep __unused)
330 {
331 ipi_cpu_handler();
332 }
333
334 void
cpu_ipi(struct cpu_info * const ci)335 cpu_ipi(struct cpu_info * const ci)
336 {
337 KASSERT(kpreempt_disabled());
338 KASSERT(curcpu() != ci);
339
340 if (ci) {
341 /* Unicast: remote CPU. */
342 alpha_send_ipi(ci->ci_cpuid, ALPHA_IPI_GENERIC);
343 } else {
344 /* Broadcast: all, but local CPU (caller will handle it). */
345 alpha_broadcast_ipi(ALPHA_IPI_GENERIC);
346 }
347 }
348