1 /*        $NetBSD: cpu_subr.c,v 1.64 2023/10/04 20:28:05 ad Exp $     */
2 
3 /*-
4  * Copyright (c) 2010, 2019, 2023 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Matt Thomas of 3am Software Foundry.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __KERNEL_RCSID(0, "$NetBSD: cpu_subr.c,v 1.64 2023/10/04 20:28:05 ad Exp $");
34 
35 #include "opt_cputype.h"
36 #include "opt_ddb.h"
37 #include "opt_modular.h"
38 #include "opt_multiprocessor.h"
39 
40 #include <sys/param.h>
41 #include <sys/atomic.h>
42 #include <sys/bitops.h>
43 #include <sys/cpu.h>
44 #include <sys/device.h>
45 #include <sys/device_impl.h>  /* XXX autoconf abuse */
46 #include <sys/idle.h>
47 #include <sys/intr.h>
48 #include <sys/ipi.h>
49 #include <sys/kernel.h>
50 #include <sys/lwp.h>
51 #include <sys/module.h>
52 #include <sys/proc.h>
53 #include <sys/ras.h>
54 #include <sys/reboot.h>
55 #include <sys/xcall.h>
56 
57 #include <uvm/uvm.h>
58 
59 #include <mips/locore.h>
60 #include <mips/regnum.h>
61 #include <mips/pcb.h>
62 #include <mips/cache.h>
63 #include <mips/frame.h>
64 #include <mips/userret.h>
65 #include <mips/pte.h>
66 
67 #if defined(DDB) || defined(KGDB)
68 #ifdef DDB
69 #include <mips/db_machdep.h>
70 #include <ddb/db_command.h>
71 #include <ddb/db_output.h>
72 #endif
73 #endif
74 
75 #ifdef MIPS64_OCTEON
76 #include <mips/cavium/octeonvar.h>
77 extern struct cpu_softc octeon_cpu_softc[];
78 #endif
79 
80 struct cpu_info cpu_info_store
81 #if defined(MULTIPROCESSOR) && !defined(MIPS64_OCTEON)
82           __section(".data1")
83           __aligned(1LU << ilog2((2*sizeof(struct cpu_info)-1)))
84 #endif
85     = {
86           .ci_curlwp = &lwp0,
87           .ci_tlb_info = &pmap_tlb0_info,
88           .ci_pmap_kern_segtab = &pmap_kern_segtab,
89           .ci_pmap_user_segtab = NULL,
90 #ifdef _LP64
91           .ci_pmap_user_seg0tab = NULL,
92 #endif
93           .ci_cpl = IPL_HIGH,
94           .ci_tlb_slot = -1,
95 #ifdef MULTIPROCESSOR
96           .ci_flags = CPUF_PRIMARY|CPUF_PRESENT|CPUF_RUNNING,
97 #endif
98 #ifdef MIPS64_OCTEON
99           .ci_softc = &octeon_cpu_softc[0],
100 #endif
101 };
102 
103 const pcu_ops_t * const pcu_ops_md_defs[PCU_UNIT_COUNT] = {
104           [PCU_FPU] = &mips_fpu_ops,
105 #if (MIPS32R2 + MIPS64R2) > 0
106           [PCU_DSP] = &mips_dsp_ops,
107 #endif
108 };
109 
110 #ifdef MULTIPROCESSOR
111 struct cpu_info * cpuid_infos[MAXCPUS] = {
112           [0] = &cpu_info_store,
113 };
114 
115 kcpuset_t *cpus_halted;
116 kcpuset_t *cpus_hatched;
117 kcpuset_t *cpus_paused;
118 kcpuset_t *cpus_resumed;
119 kcpuset_t *cpus_running;
120 
121 static void cpu_ipi_wait(const char *, const kcpuset_t *, const kcpuset_t *);
122 
123 struct cpu_info *
cpu_info_alloc(struct pmap_tlb_info * ti,cpuid_t cpu_id,cpuid_t cpu_package_id,cpuid_t cpu_core_id,cpuid_t cpu_smt_id)124 cpu_info_alloc(struct pmap_tlb_info *ti, cpuid_t cpu_id, cpuid_t cpu_package_id,
125           cpuid_t cpu_core_id, cpuid_t cpu_smt_id)
126 {
127 
128           KASSERT(cpu_id < MAXCPUS);
129 
130 #ifdef MIPS64_OCTEON
131           const int exc_step = 1 << MIPS_EBASE_EXC_BASE_SHIFT;
132           vaddr_t exc_page = MIPS_UTLB_MISS_EXC_VEC + exc_step * cpu_id;
133           __CTASSERT(sizeof(struct cpu_info) + sizeof(struct pmap_tlb_info)
134               <= exc_step - 0x280);
135 
136           struct cpu_info * const ci = ((struct cpu_info *)(exc_page + exc_step)) - 1;
137           memset((void *)exc_page, 0, exc_step);
138 
139           if (ti == NULL) {
140                     ti = ((struct pmap_tlb_info *)ci) - 1;
141                     pmap_tlb_info_init(ti);
142           }
143 #else
144           const vaddr_t cpu_info_offset = (vaddr_t)&cpu_info_store & PAGE_MASK;
145           struct pglist pglist;
146           int error;
147 
148           /*
149           * Grab a page from the first 512MB (mappable by KSEG0) to use to store
150           * exception vectors and cpu_info for this cpu.
151           */
152           error = uvm_pglistalloc(PAGE_SIZE,
153               0, MIPS_KSEG1_START - MIPS_KSEG0_START,
154               PAGE_SIZE, PAGE_SIZE, &pglist, 1, false);
155           if (error)
156                     return NULL;
157 
158           const paddr_t pa = VM_PAGE_TO_PHYS(TAILQ_FIRST(&pglist));
159           const vaddr_t va = MIPS_PHYS_TO_KSEG0(pa);
160           struct cpu_info * const ci = (void *) (va + cpu_info_offset);
161           memset((void *)va, 0, PAGE_SIZE);
162 
163           /*
164            * If we weren't passed a pmap_tlb_info to use, the caller wants us
165            * to take care of that for him.  Since we have room left over in the
166            * page we just allocated, just use a piece of that for it.
167            */
168           if (ti == NULL) {
169                     if (cpu_info_offset >= sizeof(*ti)) {
170                               ti = (void *) va;
171                     } else {
172                               KASSERT(PAGE_SIZE - cpu_info_offset + sizeof(*ci) >= sizeof(*ti));
173                               ti = (struct pmap_tlb_info *)(va + PAGE_SIZE) - 1;
174                     }
175                     pmap_tlb_info_init(ti);
176           }
177 
178           /*
179            * Attach its TLB info (which must be direct-mapped)
180            */
181 #ifdef _LP64
182           KASSERT(MIPS_KSEG0_P(ti) || MIPS_XKPHYS_P(ti));
183 #else
184           KASSERT(MIPS_KSEG0_P(ti));
185 #endif
186 #endif /* MIPS64_OCTEON */
187 
188           KASSERT(cpu_id != 0);
189           ci->ci_cpuid = cpu_id;
190           ci->ci_pmap_kern_segtab = &pmap_kern_segtab,
191           ci->ci_cpu_freq = cpu_info_store.ci_cpu_freq;
192           ci->ci_cctr_freq = cpu_info_store.ci_cctr_freq;
193           ci->ci_cycles_per_hz = cpu_info_store.ci_cycles_per_hz;
194           ci->ci_divisor_delay = cpu_info_store.ci_divisor_delay;
195           ci->ci_divisor_recip = cpu_info_store.ci_divisor_recip;
196           ci->ci_cpuwatch_count = cpu_info_store.ci_cpuwatch_count;
197 
198           cpu_topology_set(ci, cpu_package_id, cpu_core_id, cpu_smt_id, 0);
199 
200           pmap_md_alloc_ephemeral_address_space(ci);
201 
202           mi_cpu_attach(ci);
203 
204           pmap_tlb_info_attach(ti, ci);
205 
206           return ci;
207 }
208 #endif /* MULTIPROCESSOR */
209 
210 static void
cpu_hwrena_setup(void)211 cpu_hwrena_setup(void)
212 {
213 #if (MIPS32R2 + MIPS64R2) > 0
214           const int cp0flags = mips_options.mips_cpu->cpu_cp0flags;
215 
216           if ((cp0flags & MIPS_CP0FL_USE) == 0)
217                     return;
218 
219           if (CPUISMIPSNNR2) {
220                     mipsNN_cp0_hwrena_write(
221                         (MIPS_HAS_USERLOCAL ? MIPS_HWRENA_ULR : 0)
222                         | MIPS_HWRENA_CCRES
223                         | MIPS_HWRENA_CC
224                         | MIPS_HWRENA_SYNCI_STEP
225                         | MIPS_HWRENA_CPUNUM);
226                     if (MIPS_HAS_USERLOCAL) {
227                               mipsNN_cp0_userlocal_write(curlwp->l_private);
228                     }
229           }
230 #endif
231 }
232 
233 void
cpu_attach_common(device_t self,struct cpu_info * ci)234 cpu_attach_common(device_t self, struct cpu_info *ci)
235 {
236           const char * const xname = device_xname(self);
237 
238           /*
239            * Cross link cpu_info and its device together
240            *
241            * XXX autoconf abuse: Can't use device_set_private here
242            * because some callers already do so -- and some callers
243            * (sbmips cpu_attach) already have a softc allocated by
244            * autoconf.
245            */
246           ci->ci_dev = self;
247           self->dv_private = ci;
248           KASSERT(ci->ci_idepth == 0);
249 
250           evcnt_attach_dynamic(&ci->ci_ev_count_compare,
251                     EVCNT_TYPE_INTR, NULL, xname,
252                     "int 5 (clock)");
253           evcnt_attach_dynamic(&ci->ci_ev_count_compare_missed,
254                     EVCNT_TYPE_INTR, NULL, xname,
255                     "int 5 (clock) missed");
256           evcnt_attach_dynamic(&ci->ci_ev_fpu_loads,
257                     EVCNT_TYPE_MISC, NULL, xname,
258                     "fpu loads");
259           evcnt_attach_dynamic(&ci->ci_ev_fpu_saves,
260                     EVCNT_TYPE_MISC, NULL, xname,
261                     "fpu saves");
262           evcnt_attach_dynamic(&ci->ci_ev_dsp_loads,
263                     EVCNT_TYPE_MISC, NULL, xname,
264                     "dsp loads");
265           evcnt_attach_dynamic(&ci->ci_ev_dsp_saves,
266                     EVCNT_TYPE_MISC, NULL, xname,
267                     "dsp saves");
268           evcnt_attach_dynamic(&ci->ci_ev_tlbmisses,
269                     EVCNT_TYPE_TRAP, NULL, xname,
270                     "tlb misses");
271 
272 #ifdef MULTIPROCESSOR
273           if (ci != &cpu_info_store) {
274                     /*
275                      * Tail insert this onto the list of cpu_info's.
276                      * atomic_store_release matches PTR_L/SYNC_ACQ in
277                      * locore_octeon.S (XXX what about non-Octeon?).
278                      */
279                     KASSERT(cpuid_infos[ci->ci_cpuid] == NULL);
280                     atomic_store_release(&cpuid_infos[ci->ci_cpuid], ci);
281                     membar_producer(); /* Cavium sync plunger */
282           }
283           KASSERT(cpuid_infos[ci->ci_cpuid] != NULL);
284           evcnt_attach_dynamic(&ci->ci_evcnt_synci_activate_rqst,
285               EVCNT_TYPE_MISC, NULL, xname,
286               "syncicache activate request");
287           evcnt_attach_dynamic(&ci->ci_evcnt_synci_deferred_rqst,
288               EVCNT_TYPE_MISC, NULL, xname,
289               "syncicache deferred request");
290           evcnt_attach_dynamic(&ci->ci_evcnt_synci_ipi_rqst,
291               EVCNT_TYPE_MISC, NULL, xname,
292               "syncicache ipi request");
293           evcnt_attach_dynamic(&ci->ci_evcnt_synci_onproc_rqst,
294               EVCNT_TYPE_MISC, NULL, xname,
295               "syncicache onproc request");
296 
297           /*
298            * Initialize IPI framework for this cpu instance
299            */
300           ipi_init(ci);
301 
302           kcpuset_create(&ci->ci_shootdowncpus, true);
303           kcpuset_create(&ci->ci_multicastcpus, true);
304           kcpuset_create(&ci->ci_watchcpus, true);
305           kcpuset_create(&ci->ci_ddbcpus, true);
306 #endif
307 }
308 
309 void
cpu_startup_common(void)310 cpu_startup_common(void)
311 {
312           vaddr_t minaddr, maxaddr;
313           char pbuf[9];       /* "99999 MB" */
314 
315           pmap_tlb_info_evcnt_attach(&pmap_tlb0_info);
316 
317 #ifdef MULTIPROCESSOR
318           kcpuset_create(&cpus_halted, true);
319                     KASSERT(cpus_halted != NULL);
320           kcpuset_create(&cpus_hatched, true);
321                     KASSERT(cpus_hatched != NULL);
322           kcpuset_create(&cpus_paused, true);
323                     KASSERT(cpus_paused != NULL);
324           kcpuset_create(&cpus_resumed, true);
325                     KASSERT(cpus_resumed != NULL);
326           kcpuset_create(&cpus_running, true);
327                     KASSERT(cpus_running != NULL);
328           kcpuset_set(cpus_hatched, cpu_number());
329           kcpuset_set(cpus_running, cpu_number());
330 #endif
331 
332           cpu_hwrena_setup();
333 
334           /*
335            * Good {morning,afternoon,evening,night}.
336            */
337           printf("%s%s", copyright, version);
338           printf("%s\n", cpu_getmodel());
339           format_bytes(pbuf, sizeof(pbuf), ctob(physmem));
340           printf("total memory = %s\n", pbuf);
341 
342           minaddr = 0;
343           /*
344            * Allocate a submap for physio.
345            */
346           phys_map = uvm_km_suballoc(kernel_map, &minaddr, &maxaddr,
347                                             VM_PHYS_SIZE, 0, FALSE, NULL);
348 
349           /*
350            * (No need to allocate an mbuf cluster submap.  Mbuf clusters
351            * are allocated via the pool allocator, and we use KSEG/XKPHYS to
352            * map those pages.)
353            */
354 
355           format_bytes(pbuf, sizeof(pbuf), ptoa(uvm_availmem(false)));
356           printf("avail memory = %s\n", pbuf);
357 
358 #if defined(__mips_n32)
359           module_machine = "mips-n32";
360 #endif
361 }
362 
363 void
cpu_getmcontext(struct lwp * l,mcontext_t * mcp,unsigned int * flags)364 cpu_getmcontext(struct lwp *l, mcontext_t *mcp, unsigned int *flags)
365 {
366           const struct trapframe *tf = l->l_md.md_utf;
367           __greg_t *gr = mcp->__gregs;
368           __greg_t ras_pc;
369 
370           /* Save register context. Dont copy R0 - it is always 0 */
371           memcpy(&gr[_REG_AT], &tf->tf_regs[_R_AST], sizeof(mips_reg_t) * 31);
372 
373           gr[_REG_MDLO]  = tf->tf_regs[_R_MULLO];
374           gr[_REG_MDHI]  = tf->tf_regs[_R_MULHI];
375           gr[_REG_CAUSE] = tf->tf_regs[_R_CAUSE];
376           gr[_REG_EPC]   = tf->tf_regs[_R_PC];
377           gr[_REG_SR]    = tf->tf_regs[_R_SR];
378           mcp->_mc_tlsbase = (intptr_t)l->l_private;
379 
380           if ((ras_pc = (intptr_t)ras_lookup(l->l_proc,
381               (void *) (intptr_t)gr[_REG_EPC])) != -1)
382                     gr[_REG_EPC] = ras_pc;
383 
384           *flags |= _UC_CPU | _UC_TLSBASE;
385 
386           /* Save floating point register context, if any. */
387           KASSERT(l == curlwp);
388           if (fpu_used_p(l)) {
389                     size_t fplen;
390                     /*
391                      * If this process is the current FP owner, dump its
392                      * context to the PCB first.
393                      */
394                     fpu_save(l);
395 
396                     /*
397                      * The PCB FP regs struct includes the FP CSR, so use the
398                      * size of __fpregs.__fp_r when copying.
399                      */
400 #if !defined(__mips_o32)
401                     if (_MIPS_SIM_NEWABI_P(l->l_proc->p_md.md_abi)) {
402 #endif
403                               fplen = sizeof(struct fpreg);
404 #if !defined(__mips_o32)
405                     } else {
406                               fplen = sizeof(struct fpreg_oabi);
407                     }
408 #endif
409                     struct pcb * const pcb = lwp_getpcb(l);
410                     memcpy(&mcp->__fpregs, &pcb->pcb_fpregs, fplen);
411                     *flags |= _UC_FPU;
412           }
413 }
414 
415 int
cpu_mcontext_validate(struct lwp * l,const mcontext_t * mcp)416 cpu_mcontext_validate(struct lwp *l, const mcontext_t *mcp)
417 {
418 
419           /* XXX:  Do we validate the addresses?? */
420           return 0;
421 }
422 
423 int
cpu_setmcontext(struct lwp * l,const mcontext_t * mcp,unsigned int flags)424 cpu_setmcontext(struct lwp *l, const mcontext_t *mcp, unsigned int flags)
425 {
426           struct trapframe *tf = l->l_md.md_utf;
427           struct proc *p = l->l_proc;
428           const __greg_t *gr = mcp->__gregs;
429           int error;
430 
431           /* Restore register context, if any. */
432           if (flags & _UC_CPU) {
433                     error = cpu_mcontext_validate(l, mcp);
434                     if (error)
435                               return error;
436 
437                     /* Save register context. */
438 
439 #ifdef __mips_n32
440                     CTASSERT(_R_AST == _REG_AT);
441                     if (__predict_false(p->p_md.md_abi == _MIPS_BSD_API_O32)) {
442                               const mcontext_o32_t *mcp32 = (const mcontext_o32_t *)mcp;
443                               const __greg32_t *gr32 = mcp32->__gregs;
444                               for (size_t i = _R_AST; i < 32; i++) {
445                                         tf->tf_regs[i] = gr32[i];
446                               }
447                     } else
448 #endif
449                     memcpy(&tf->tf_regs[_R_AST], &gr[_REG_AT],
450                            sizeof(mips_reg_t) * 31);
451 
452                     tf->tf_regs[_R_MULLO] = gr[_REG_MDLO];
453                     tf->tf_regs[_R_MULHI] = gr[_REG_MDHI];
454                     tf->tf_regs[_R_CAUSE] = gr[_REG_CAUSE];
455                     tf->tf_regs[_R_PC]    = gr[_REG_EPC];
456                     /* Do not restore SR. */
457           }
458 
459           /* Restore the private thread context */
460           if (flags & _UC_TLSBASE) {
461                     lwp_setprivate(l, (void *)(intptr_t)mcp->_mc_tlsbase);
462           }
463 
464           /* Restore floating point register context, if any. */
465           if (flags & _UC_FPU) {
466                     size_t fplen;
467 
468                     /* Disable the FPU contents. */
469                     fpu_discard(l);
470 
471 #if !defined(__mips_o32)
472                     if (_MIPS_SIM_NEWABI_P(l->l_proc->p_md.md_abi)) {
473 #endif
474                               fplen = sizeof(struct fpreg);
475 #if !defined(__mips_o32)
476                     } else {
477                               fplen = sizeof(struct fpreg_oabi);
478                     }
479 #endif
480                     /*
481                      * The PCB FP regs struct includes the FP CSR, so use the
482                      * proper size of fpreg when copying.
483                      */
484                     struct pcb * const pcb = lwp_getpcb(l);
485                     memcpy(&pcb->pcb_fpregs, &mcp->__fpregs, fplen);
486           }
487 
488           mutex_enter(p->p_lock);
489           if (flags & _UC_SETSTACK)
490                     l->l_sigstk.ss_flags |= SS_ONSTACK;
491           if (flags & _UC_CLRSTACK)
492                     l->l_sigstk.ss_flags &= ~SS_ONSTACK;
493           mutex_exit(p->p_lock);
494 
495           return (0);
496 }
497 
498 void
cpu_need_resched(struct cpu_info * ci,struct lwp * l,int flags)499 cpu_need_resched(struct cpu_info *ci, struct lwp *l, int flags)
500 {
501 
502           KASSERT(kpreempt_disabled());
503 
504           if ((flags & RESCHED_KPREEMPT) != 0) {
505 #ifdef __HAVE_PREEMPTION
506                     if ((flags & RESCHED_REMOTE) != 0) {
507                               cpu_send_ipi(ci, IPI_KPREEMPT);
508                     } else {
509                               softint_trigger(SOFTINT_KPREEMPT);
510                     }
511 #endif
512                     return;
513           }
514           if ((flags & RESCHED_REMOTE) != 0) {
515 #ifdef MULTIPROCESSOR
516                     cpu_send_ipi(ci, IPI_AST);
517 #endif
518           } else {
519                     l->l_md.md_astpending = 1;              /* force call to ast() */
520           }
521 }
522 
523 uint32_t
cpu_clkf_usermode_mask(void)524 cpu_clkf_usermode_mask(void)
525 {
526 
527           return CPUISMIPS3 ? MIPS_SR_KSU_USER : MIPS_SR_KU_PREV;
528 }
529 
530 void
cpu_signotify(struct lwp * l)531 cpu_signotify(struct lwp *l)
532 {
533 
534           KASSERT(kpreempt_disabled());
535 #ifdef __HAVE_FAST_SOFTINTS
536           KASSERT(lwp_locked(l, NULL));
537 #endif
538 
539           if (l->l_cpu != curcpu()) {
540 #ifdef MULTIPROCESSOR
541                     cpu_send_ipi(l->l_cpu, IPI_AST);
542 #endif
543           } else {
544                     l->l_md.md_astpending = 1;    /* force call to ast() */
545           }
546 }
547 
548 void
cpu_need_proftick(struct lwp * l)549 cpu_need_proftick(struct lwp *l)
550 {
551 
552           KASSERT(kpreempt_disabled());
553           KASSERT(l->l_cpu == curcpu());
554 
555           l->l_pflag |= LP_OWEUPC;
556           l->l_md.md_astpending = 1;              /* force call to ast() */
557 }
558 
559 #ifdef __HAVE_PREEMPTION
560 bool
cpu_kpreempt_enter(uintptr_t where,int s)561 cpu_kpreempt_enter(uintptr_t where, int s)
562 {
563 
564           KASSERT(kpreempt_disabled());
565 
566 #if 0
567           if (where == (intptr_t)-2) {
568                     KASSERT(curcpu()->ci_mtx_count == 0);
569                     /*
570                      * We must be called via kern_intr (which already checks for
571                      * IPL_NONE so of course we call be preempted).
572                      */
573                     return true;
574           }
575           /*
576            * We are called from KPREEMPT_ENABLE().  If we are at IPL_NONE,
577            * of course we can be preempted.  If we aren't, ask for a
578            * softint so that kern_intr can call kpreempt.
579            */
580           if (s == IPL_NONE) {
581                     KASSERT(curcpu()->ci_mtx_count == 0);
582                     return true;
583           }
584           softint_trigger(SOFTINT_KPREEMPT);
585 #endif
586           return false;
587 }
588 
589 void
cpu_kpreempt_exit(uintptr_t where)590 cpu_kpreempt_exit(uintptr_t where)
591 {
592 
593           /* do nothing */
594 }
595 
596 /*
597  * Return true if preemption is disabled for MD reasons.  Must be called
598  * with preemption disabled, and thus is only for diagnostic checks.
599  */
600 bool
cpu_kpreempt_disabled(void)601 cpu_kpreempt_disabled(void)
602 {
603 
604           /*
605            * Any elevated IPL disables preemption.
606            */
607           return curcpu()->ci_cpl > IPL_NONE;
608 }
609 #endif /* __HAVE_PREEMPTION */
610 
611 void
cpu_idle(void)612 cpu_idle(void)
613 {
614           void (*const mach_idle)(void) = mips_locoresw.lsw_cpu_idle;
615           struct cpu_info * const ci = curcpu();
616 
617           while (!ci->ci_want_resched) {
618 #ifdef __HAVE_FAST_SOFTINTS
619                     KASSERT(ci->ci_data.cpu_softints == 0);
620 #endif
621                     (*mach_idle)();
622           }
623 }
624 
625 bool
cpu_intr_p(void)626 cpu_intr_p(void)
627 {
628           int idepth;
629           long pctr;
630           lwp_t *l;
631 
632           l = curlwp;
633           do {
634                     pctr = lwp_pctr();
635                     idepth = l->l_cpu->ci_idepth;
636           } while (__predict_false(pctr != lwp_pctr()));
637 
638           return idepth != 0;
639 }
640 
641 #ifdef MULTIPROCESSOR
642 
643 void
cpu_broadcast_ipi(int tag)644 cpu_broadcast_ipi(int tag)
645 {
646 
647           // No reason to remove ourselves since multicast_ipi will do that for us
648           cpu_multicast_ipi(cpus_running, tag);
649 }
650 
651 void
cpu_multicast_ipi(const kcpuset_t * kcp,int tag)652 cpu_multicast_ipi(const kcpuset_t *kcp, int tag)
653 {
654           struct cpu_info * const ci = curcpu();
655           kcpuset_t *kcp2 = ci->ci_multicastcpus;
656 
657           if (kcpuset_match(cpus_running, ci->ci_kcpuset))
658                     return;
659 
660           kcpuset_copy(kcp2, kcp);
661           kcpuset_remove(kcp2, ci->ci_kcpuset);
662           for (cpuid_t cii; (cii = kcpuset_ffs(kcp2)) != 0; ) {
663                     kcpuset_clear(kcp2, --cii);
664                     (void)cpu_send_ipi(cpu_lookup(cii), tag);
665           }
666 }
667 
668 int
cpu_send_ipi(struct cpu_info * ci,int tag)669 cpu_send_ipi(struct cpu_info *ci, int tag)
670 {
671 
672           return (*mips_locoresw.lsw_send_ipi)(ci, tag);
673 }
674 
675 static void
cpu_ipi_wait(const char * s,const kcpuset_t * watchset,const kcpuset_t * wanted)676 cpu_ipi_wait(const char *s, const kcpuset_t *watchset, const kcpuset_t *wanted)
677 {
678           bool done = false;
679           struct cpu_info * const ci = curcpu();
680           kcpuset_t *kcp = ci->ci_watchcpus;
681 
682           /* some finite amount of time */
683 
684           for (u_long limit = curcpu()->ci_cpu_freq/10; !done && limit--; ) {
685                     kcpuset_copy(kcp, watchset);
686                     kcpuset_intersect(kcp, wanted);
687                     done = kcpuset_match(kcp, wanted);
688           }
689 
690           if (!done) {
691                     cpuid_t cii;
692                     kcpuset_copy(kcp, wanted);
693                     kcpuset_remove(kcp, watchset);
694                     if ((cii = kcpuset_ffs(kcp)) != 0) {
695                               printf("Failed to %s:", s);
696                               do {
697                                         kcpuset_clear(kcp, --cii);
698                                         printf(" cpu%lu", cii);
699                               } while ((cii = kcpuset_ffs(kcp)) != 0);
700                               printf("\n");
701                     }
702           }
703 }
704 
705 /*
706  * Halt this cpu
707  */
708 void
cpu_halt(void)709 cpu_halt(void)
710 {
711           cpuid_t cii = cpu_index(curcpu());
712 
713           printf("cpu%lu: shutting down\n", cii);
714           kcpuset_atomic_set(cpus_halted, cii);
715           spl0();             /* allow interrupts e.g. further ipi ? */
716           for (;;) ;          /* spin */
717 
718           /* NOTREACHED */
719 }
720 
721 /*
722  * Halt all running cpus, excluding current cpu.
723  */
724 void
cpu_halt_others(void)725 cpu_halt_others(void)
726 {
727           kcpuset_t *kcp;
728 
729           // If we are the only CPU running, there's nothing to do.
730           if (kcpuset_match(cpus_running, curcpu()->ci_kcpuset))
731                     return;
732 
733           // Get all running CPUs
734           kcpuset_clone(&kcp, cpus_running);
735           // Remove ourself
736           kcpuset_remove(kcp, curcpu()->ci_kcpuset);
737           // Remove any halted CPUs
738           kcpuset_remove(kcp, cpus_halted);
739           // If there are CPUs left, send the IPIs
740           if (!kcpuset_iszero(kcp)) {
741                     cpu_multicast_ipi(kcp, IPI_HALT);
742                     cpu_ipi_wait("halt", cpus_halted, kcp);
743           }
744           kcpuset_destroy(kcp);
745 
746           /*
747            * TBD
748            * Depending on available firmware methods, other cpus will
749            * either shut down themselves, or spin and wait for us to
750            * stop them.
751            */
752 }
753 
754 /*
755  * Pause this cpu
756  */
757 void
cpu_pause(struct reg * regsp)758 cpu_pause(struct reg *regsp)
759 {
760           int s = splhigh();
761           cpuid_t cii = cpu_index(curcpu());
762 
763           if (__predict_false(cold)) {
764                     splx(s);
765                     return;
766           }
767 
768           do {
769                     kcpuset_atomic_set(cpus_paused, cii);
770                     do {
771                               ;
772                     } while (kcpuset_isset(cpus_paused, cii));
773                     kcpuset_atomic_set(cpus_resumed, cii);
774 #if defined(DDB)
775                     if (ddb_running_on_this_cpu_p())
776                               cpu_Debugger();
777                     if (ddb_running_on_any_cpu_p())
778                               continue;
779 #endif
780           } while (false);
781 
782           splx(s);
783 }
784 
785 /*
786  * Pause all running cpus, excluding current cpu.
787  */
788 void
cpu_pause_others(void)789 cpu_pause_others(void)
790 {
791           struct cpu_info * const ci = curcpu();
792 
793           if (cold || kcpuset_match(cpus_running, ci->ci_kcpuset))
794                     return;
795 
796           kcpuset_t *kcp = ci->ci_ddbcpus;
797 
798           kcpuset_copy(kcp, cpus_running);
799           kcpuset_remove(kcp, ci->ci_kcpuset);
800           kcpuset_remove(kcp, cpus_paused);
801 
802           cpu_broadcast_ipi(IPI_SUSPEND);
803           cpu_ipi_wait("pause", cpus_paused, kcp);
804 }
805 
806 /*
807  * Resume a single cpu
808  */
809 void
cpu_resume(cpuid_t cii)810 cpu_resume(cpuid_t cii)
811 {
812 
813           if (__predict_false(cold))
814                     return;
815 
816           struct cpu_info * const ci = curcpu();
817           kcpuset_t *kcp = ci->ci_ddbcpus;
818 
819           kcpuset_set(kcp, cii);
820           kcpuset_atomicly_remove(cpus_resumed, cpus_resumed);
821           kcpuset_atomic_clear(cpus_paused, cii);
822 
823           cpu_ipi_wait("resume", cpus_resumed, kcp);
824 }
825 
826 /*
827  * Resume all paused cpus.
828  */
829 void
cpu_resume_others(void)830 cpu_resume_others(void)
831 {
832 
833           if (__predict_false(cold))
834                     return;
835 
836           struct cpu_info * const ci = curcpu();
837           kcpuset_t *kcp = ci->ci_ddbcpus;
838 
839           kcpuset_atomicly_remove(cpus_resumed, cpus_resumed);
840           kcpuset_copy(kcp, cpus_paused);
841           kcpuset_atomicly_remove(cpus_paused, cpus_paused);
842 
843           /* CPUs awake on cpus_paused clear */
844           cpu_ipi_wait("resume", cpus_resumed, kcp);
845 }
846 
847 bool
cpu_is_paused(cpuid_t cii)848 cpu_is_paused(cpuid_t cii)
849 {
850 
851           return !cold && kcpuset_isset(cpus_paused, cii);
852 }
853 
854 #ifdef DDB
855 void
cpu_debug_dump(void)856 cpu_debug_dump(void)
857 {
858           CPU_INFO_ITERATOR cii;
859           struct cpu_info *ci;
860           char running, hatched, paused, resumed, halted;
861           db_printf("CPU CPUID STATE CPUINFO            CPL INT MTX IPIS(A/R)\n");
862           for (CPU_INFO_FOREACH(cii, ci)) {
863                     hatched = (kcpuset_isset(cpus_hatched, cpu_index(ci)) ? 'H' : '-');
864                     running = (kcpuset_isset(cpus_running, cpu_index(ci)) ? 'R' : '-');
865                     paused  = (kcpuset_isset(cpus_paused,  cpu_index(ci)) ? 'P' : '-');
866                     resumed = (kcpuset_isset(cpus_resumed, cpu_index(ci)) ? 'r' : '-');
867                     halted  = (kcpuset_isset(cpus_halted,  cpu_index(ci)) ? 'h' : '-');
868                     db_printf("%3d 0x%03lx %c%c%c%c%c %p "
869                               "%3d %3d %3d "
870                               "0x%02" PRIx64 "/0x%02" PRIx64 "\n",
871                               cpu_index(ci), ci->ci_cpuid,
872                               running, hatched, paused, resumed, halted,
873                               ci, ci->ci_cpl, ci->ci_idepth, ci->ci_mtx_count,
874                               ci->ci_active_ipis, ci->ci_request_ipis);
875           }
876 }
877 #endif
878 
879 void
cpu_hatch(struct cpu_info * ci)880 cpu_hatch(struct cpu_info *ci)
881 {
882           struct pmap_tlb_info * const ti = ci->ci_tlb_info;
883 
884           /*
885            * Invalidate all the TLB enties (even wired ones) and then reserve
886            * space for the wired TLB entries.
887            */
888           mips3_cp0_wired_write(0);
889           tlb_invalidate_all();
890           mips3_cp0_wired_write(ti->ti_wired);
891 
892           /*
893            * Setup HWRENA and USERLOCAL COP0 registers (MIPSxxR2).
894            */
895           cpu_hwrena_setup();
896 
897           /*
898            * If we are using register zero relative addressing to access cpu_info
899            * in the exception vectors, enter that mapping into TLB now.
900            */
901           if (ci->ci_tlb_slot >= 0) {
902                     const uint32_t tlb_lo = MIPS3_PG_G|MIPS3_PG_V
903                         | mips3_paddr_to_tlbpfn((vaddr_t)ci);
904                     const struct tlbmask tlbmask = {
905                               .tlb_hi = -PAGE_SIZE | KERNEL_PID,
906 #if (PGSHIFT & 1)
907                               .tlb_lo0 = tlb_lo,
908                               .tlb_lo1 = tlb_lo + MIPS3_PG_NEXT,
909 #else
910                               .tlb_lo0 = 0,
911                               .tlb_lo1 = tlb_lo,
912 #endif
913                               .tlb_mask = -1,
914                     };
915 
916                     tlb_invalidate_addr(tlbmask.tlb_hi, KERNEL_PID);
917                     tlb_write_entry(ci->ci_tlb_slot, &tlbmask);
918           }
919 
920           /*
921            * Flush the icache just be sure.
922            */
923           mips_icache_sync_all();
924 
925           /*
926            * Let this CPU do its own initialization (for things that have to be
927            * done on the local CPU).
928            */
929           (*mips_locoresw.lsw_cpu_init)(ci);
930 
931           // Show this CPU as present.
932           atomic_or_ulong(&ci->ci_flags, CPUF_PRESENT);
933 
934           /*
935            * Announce we are hatched
936            */
937           kcpuset_atomic_set(cpus_hatched, cpu_index(ci));
938 
939           /*
940            * Now wait to be set free!
941            */
942           while (! kcpuset_isset(cpus_running, cpu_index(ci))) {
943                     /* spin, spin, spin */
944           }
945 
946           /*
947            * initialize the MIPS count/compare clock
948            */
949           mips3_cp0_count_write(ci->ci_data.cpu_cc_skew);
950           KASSERT(ci->ci_cycles_per_hz != 0);
951           ci->ci_next_cp0_clk_intr = ci->ci_data.cpu_cc_skew + ci->ci_cycles_per_hz;
952           mips3_cp0_compare_write(ci->ci_next_cp0_clk_intr);
953           ci->ci_data.cpu_cc_skew = 0;
954 
955           /*
956            * Let this CPU do its own post-running initialization
957            * (for things that have to be done on the local CPU).
958            */
959           (*mips_locoresw.lsw_cpu_run)(ci);
960 
961           /*
962            * Now turn on interrupts (and verify they are on).
963            */
964           spl0();
965           KASSERTMSG(ci->ci_cpl == IPL_NONE, "cpl %d", ci->ci_cpl);
966           KASSERT(mips_cp0_status_read() & MIPS_SR_INT_IE);
967 
968           kcpuset_atomic_set(pmap_kernel()->pm_onproc, cpu_index(ci));
969           kcpuset_atomic_set(pmap_kernel()->pm_active, cpu_index(ci));
970 
971           /*
972            * And do a tail call to idle_loop
973            */
974           idle_loop(NULL);
975 }
976 
977 void
cpu_boot_secondary_processors(void)978 cpu_boot_secondary_processors(void)
979 {
980           CPU_INFO_ITERATOR cii;
981           struct cpu_info *ci;
982 
983           if ((boothowto & RB_MD1) != 0)
984                     return;
985 
986           for (CPU_INFO_FOREACH(cii, ci)) {
987                     if (CPU_IS_PRIMARY(ci))
988                               continue;
989                     KASSERT(ci->ci_data.cpu_idlelwp);
990 
991                     /*
992                      * Skip this CPU if it didn't successfully hatch.
993                      */
994                     if (!kcpuset_isset(cpus_hatched, cpu_index(ci)))
995                               continue;
996 
997                     ci->ci_data.cpu_cc_skew = mips3_cp0_count_read();
998                     atomic_or_ulong(&ci->ci_flags, CPUF_RUNNING);
999                     kcpuset_set(cpus_running, cpu_index(ci));
1000                     // Spin until the cpu calls idle_loop
1001                     for (u_int i = 0; i < 10000; i++) {
1002                               if (kcpuset_isset(kcpuset_running, cpu_index(ci)))
1003                                         break;
1004                               delay(1000);
1005                     }
1006           }
1007 }
1008 
1009 void
xc_send_ipi(struct cpu_info * ci)1010 xc_send_ipi(struct cpu_info *ci)
1011 {
1012 
1013           (*mips_locoresw.lsw_send_ipi)(ci, IPI_XCALL);
1014 }
1015 
1016 void
cpu_ipi(struct cpu_info * ci)1017 cpu_ipi(struct cpu_info *ci)
1018 {
1019 
1020           (*mips_locoresw.lsw_send_ipi)(ci, IPI_GENERIC);
1021 }
1022 
1023 #endif /* MULTIPROCESSOR */
1024 
1025 void
cpu_offline_md(void)1026 cpu_offline_md(void)
1027 {
1028 
1029           (*mips_locoresw.lsw_cpu_offline_md)();
1030 }
1031 
1032 #ifdef _LP64
1033 void
cpu_vmspace_exec(lwp_t * l,vaddr_t start,vaddr_t end)1034 cpu_vmspace_exec(lwp_t *l, vaddr_t start, vaddr_t end)
1035 {
1036           /*
1037            * We need to turn on/off UX so that copyout/copyin will work
1038            * well before setreg gets called.
1039            */
1040           uint32_t sr = mips_cp0_status_read();
1041 
1042           if (end != (uint32_t) end) {
1043                     mips_cp0_status_write(sr | MIPS3_SR_UX);
1044           } else {
1045                     mips_cp0_status_write(sr & ~MIPS3_SR_UX);
1046           }
1047 }
1048 #endif
1049 
1050 int
cpu_lwp_setprivate(lwp_t * l,void * v)1051 cpu_lwp_setprivate(lwp_t *l, void *v)
1052 {
1053 
1054 #if (MIPS32R2 + MIPS64R2) > 0
1055           if (l == curlwp && MIPS_HAS_USERLOCAL) {
1056                     mipsNN_cp0_userlocal_write(v);
1057           }
1058 #endif
1059           return 0;
1060 }
1061 
1062 
1063 #if (MIPS32 + MIPS32R2 + MIPS64 + MIPS64R2) > 0
1064 
1065 #if (CPUWATCH_MAX != 8)
1066 # error CPUWATCH_MAX
1067 #endif
1068 
1069 /*
1070  * cpuwatch_discover - determine how many COP0 watchpoints this CPU supports
1071  */
1072 u_int
cpuwatch_discover(void)1073 cpuwatch_discover(void)
1074 {
1075           int i;
1076 
1077           for (i=0; i < CPUWATCH_MAX; i++) {
1078                     uint32_t watchhi = mipsNN_cp0_watchhi_read(i);
1079                     if ((watchhi & __BIT(31)) == 0)         /* test 'M' bit */
1080                               break;
1081           }
1082           return i + 1;
1083 }
1084 
1085 void
cpuwatch_free(cpu_watchpoint_t * cwp)1086 cpuwatch_free(cpu_watchpoint_t *cwp)
1087 {
1088 #ifdef DIAGNOSTIC
1089           struct cpu_info * const ci = curcpu();
1090 
1091           KASSERT(cwp >= &ci->ci_cpuwatch_tab[0] &&
1092                     cwp <= &ci->ci_cpuwatch_tab[ci->ci_cpuwatch_count-1]);
1093 #endif
1094           cwp->cw_mode = 0;
1095           cwp->cw_asid = 0;
1096           cwp->cw_addr = 0;
1097           cpuwatch_clr(cwp);
1098 }
1099 
1100 /*
1101  * cpuwatch_alloc
1102  *        find an empty slot
1103  *        no locking for the table since it is CPU private
1104  */
1105 cpu_watchpoint_t *
cpuwatch_alloc(void)1106 cpuwatch_alloc(void)
1107 {
1108           struct cpu_info * const ci = curcpu();
1109           cpu_watchpoint_t *cwp;
1110 
1111           for (int i=0; i < ci->ci_cpuwatch_count; i++) {
1112                     cwp = &ci->ci_cpuwatch_tab[i];
1113                     if ((cwp->cw_mode & CPUWATCH_RWX) == 0)
1114                               return cwp;
1115           }
1116           return NULL;
1117 }
1118 
1119 
1120 void
cpuwatch_set_all(void)1121 cpuwatch_set_all(void)
1122 {
1123           struct cpu_info * const ci = curcpu();
1124           cpu_watchpoint_t *cwp;
1125           int i;
1126 
1127           for (i=0; i < ci->ci_cpuwatch_count; i++) {
1128                     cwp = &ci->ci_cpuwatch_tab[i];
1129                     if ((cwp->cw_mode & CPUWATCH_RWX) != 0)
1130                               cpuwatch_set(cwp);
1131           }
1132 }
1133 
1134 void
cpuwatch_clr_all(void)1135 cpuwatch_clr_all(void)
1136 {
1137           struct cpu_info * const ci = curcpu();
1138           cpu_watchpoint_t *cwp;
1139           int i;
1140 
1141           for (i=0; i < ci->ci_cpuwatch_count; i++) {
1142                     cwp = &ci->ci_cpuwatch_tab[i];
1143                     if ((cwp->cw_mode & CPUWATCH_RWX) != 0)
1144                               cpuwatch_clr(cwp);
1145           }
1146 }
1147 
1148 /*
1149  * cpuwatch_set - establish a MIPS COP0 watchpoint
1150  */
1151 void
cpuwatch_set(cpu_watchpoint_t * cwp)1152 cpuwatch_set(cpu_watchpoint_t *cwp)
1153 {
1154           struct cpu_info * const ci = curcpu();
1155           uint32_t watchhi;
1156           register_t watchlo;
1157           int cwnum = cwp - &ci->ci_cpuwatch_tab[0];
1158 
1159           KASSERT(cwp >= &ci->ci_cpuwatch_tab[0] &&
1160                     cwp <= &ci->ci_cpuwatch_tab[ci->ci_cpuwatch_count-1]);
1161 
1162           watchlo = cwp->cw_addr;
1163           if (cwp->cw_mode & CPUWATCH_WRITE)
1164                     watchlo |= __BIT(0);
1165           if (cwp->cw_mode & CPUWATCH_READ)
1166                     watchlo |= __BIT(1);
1167           if (cwp->cw_mode & CPUWATCH_EXEC)
1168                     watchlo |= __BIT(2);
1169 
1170           if (cwp->cw_mode & CPUWATCH_ASID)
1171                     watchhi = cwp->cw_asid << 16; /* addr qualified by asid */
1172           else
1173                     watchhi = __BIT(30);                    /* addr not qual. by asid (Global) */
1174           if (cwp->cw_mode & CPUWATCH_MASK)
1175                     watchhi |= cwp->cw_mask;      /* set "dont care" addr match bits */
1176 
1177           mipsNN_cp0_watchhi_write(cwnum, watchhi);
1178           mipsNN_cp0_watchlo_write(cwnum, watchlo);
1179 }
1180 
1181 /*
1182  * cpuwatch_clr - disestablish a MIPS COP0 watchpoint
1183  */
1184 void
cpuwatch_clr(cpu_watchpoint_t * cwp)1185 cpuwatch_clr(cpu_watchpoint_t *cwp)
1186 {
1187           struct cpu_info * const ci = curcpu();
1188           int cwnum = cwp - &ci->ci_cpuwatch_tab[0];
1189 
1190           KASSERT(cwp >= &ci->ci_cpuwatch_tab[0] &&
1191                     cwp <= &ci->ci_cpuwatch_tab[ci->ci_cpuwatch_count-1]);
1192 
1193           mipsNN_cp0_watchhi_write(cwnum, 0);
1194           mipsNN_cp0_watchlo_write(cwnum, 0);
1195 }
1196 
1197 #endif    /* (MIPS32 + MIPS32R2 + MIPS64 + MIPS64R2) > 0 */
1198