Home | History | Annotate | Line # | Download | only in dev
cpu.c revision 1.78 
      1 /* $NetBSD: cpu.c,v 1.78 2018/05/29 07:35:40 reinoud Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2007 Jared D. McNeill <jmcneill (at) invisible.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include "opt_cpu.h"
     30 #include "opt_hz.h"
     31 
     32 #include <sys/cdefs.h>
     33 __KERNEL_RCSID(0, "$NetBSD: cpu.c,v 1.78 2018/05/29 07:35:40 reinoud Exp $");
     34 
     35 #include <sys/param.h>
     36 #include <sys/conf.h>
     37 #include <sys/proc.h>
     38 #include <sys/systm.h>
     39 #include <sys/device.h>
     40 #include <sys/reboot.h>
     41 #include <sys/lwp.h>
     42 #include <sys/cpu.h>
     43 #include <sys/mbuf.h>
     44 #include <sys/msgbuf.h>
     45 #include <sys/kmem.h>
     46 #include <sys/kernel.h>
     47 #include <sys/mount.h>
     48 
     49 #include <dev/cons.h>
     50 
     51 #include <machine/cpu.h>
     52 #include <machine/mainbus.h>
     53 #include <machine/pcb.h>
     54 #include <machine/machdep.h>
     55 #include <machine/thunk.h>
     56 
     57 #include <uvm/uvm_extern.h>
     58 #include <uvm/uvm_page.h>
     59 
     60 #if __GNUC_PREREQ__(4,4)
     61 #define cpu_unreachable()	__builtin_unreachable()
     62 #else
     63 #define cpu_unreachable()	do { thunk_abort(); } while (0)
     64 #endif
     65 
     66 static int	cpu_match(device_t, cfdata_t, void *);
     67 static void	cpu_attach(device_t, device_t, void *);
     68 
     69 /* XXX */
     70 //extern void *_lwp_getprivate(void);
     71 //extern int _lwp_setprivate(void *);
     72 
     73 
     74 struct cpu_info cpu_info_primary = {
     75 	.ci_dev = 0,
     76 	.ci_self = &cpu_info_primary,
     77 	.ci_idepth = -1,
     78 	.ci_curlwp = &lwp0,
     79 };
     80 
     81 typedef struct cpu_softc {
     82 	device_t	sc_dev;
     83 	struct cpu_info	*sc_ci;
     84 
     85 	ucontext_t	sc_ucp;
     86 	uint8_t		sc_ucp_stack[PAGE_SIZE];
     87 } cpu_softc_t;
     88 
     89 
     90 /* statics */
     91 static struct pcb lwp0pcb;
     92 static void *um_msgbuf;
     93 
     94 
     95 /* attachment */
     96 CFATTACH_DECL_NEW(cpu, sizeof(cpu_softc_t), cpu_match, cpu_attach, NULL, NULL);
     97 
     98 static int
     99 cpu_match(device_t parent, cfdata_t match, void *opaque)
    100 {
    101 	struct thunkbus_attach_args *taa = opaque;
    102 
    103 	if (taa->taa_type != THUNKBUS_TYPE_CPU)
    104 		return 0;
    105 
    106 	return 1;
    107 }
    108 
    109 static void
    110 cpu_attach(device_t parent, device_t self, void *opaque)
    111 {
    112 	cpu_softc_t *sc = device_private(self);
    113 
    114 	aprint_naive("\n");
    115 	aprint_normal("\n");
    116 
    117 	cpu_info_primary.ci_dev = self;
    118 	sc->sc_dev = self;
    119 	sc->sc_ci = &cpu_info_primary;
    120 
    121 	thunk_getcontext(&sc->sc_ucp);
    122 	sc->sc_ucp.uc_stack.ss_sp = sc->sc_ucp_stack;
    123 	sc->sc_ucp.uc_stack.ss_size = PAGE_SIZE - sizeof(register_t);
    124 	sc->sc_ucp.uc_flags = _UC_STACK | _UC_CPU | _UC_SIGMASK;
    125 	thunk_sigaddset(&sc->sc_ucp.uc_sigmask, SIGALRM);
    126 	thunk_sigaddset(&sc->sc_ucp.uc_sigmask, SIGIO);
    127 	thunk_sigaddset(&sc->sc_ucp.uc_sigmask, SIGINT);
    128 	thunk_sigaddset(&sc->sc_ucp.uc_sigmask, SIGTSTP);
    129 }
    130 
    131 void
    132 cpu_configure(void)
    133 {
    134 	cpu_setmodel("virtual processor");
    135 	if (config_rootfound("mainbus", NULL) == NULL)
    136 		panic("configure: mainbus not configured");
    137 
    138 	spl0();
    139 }
    140 
    141 
    142 /* main guts */
    143 void
    144 cpu_reboot(int howto, char *bootstr)
    145 {
    146 	extern void usermode_reboot(void);
    147 
    148 	if (cold)
    149 		howto |= RB_HALT;
    150 
    151 	if ((howto & RB_NOSYNC) == 0)
    152 		vfs_shutdown();
    153 	else
    154 		suspendsched();
    155 
    156 	doshutdownhooks();
    157 	pmf_system_shutdown(boothowto);
    158 
    159 	if ((howto & RB_POWERDOWN) == RB_POWERDOWN)
    160 		thunk_exit(0);
    161 
    162 	splhigh();
    163 
    164 	if (howto & RB_DUMP)
    165 		thunk_abort();
    166 
    167 	if (howto & RB_HALT) {
    168 		printf("\n");
    169 		printf("The operating system has halted.\n");
    170 		printf("Please press any key to reboot.\n\n");
    171 		cnpollc(1);
    172 		cngetc();
    173 		cnpollc(0);
    174 	}
    175 
    176 	printf("rebooting...\n");
    177 
    178 	usermode_reboot();
    179 
    180 	/* NOTREACHED */
    181 	cpu_unreachable();
    182 }
    183 
    184 void
    185 cpu_need_resched(struct cpu_info *ci, int flags)
    186 {
    187 	ci->ci_want_resched |= flags;
    188 	aston(ci);
    189 }
    190 
    191 void
    192 cpu_need_proftick(struct lwp *l)
    193 {
    194 }
    195 
    196 int
    197 cpu_lwp_setprivate(lwp_t *l, void *ptr)
    198 {
    199 	struct pcb *pcb = lwp_getpcb(l);
    200 
    201 	/* set both ucontexts up for TLS just in case */
    202 	pcb->pcb_ucp.uc_mcontext._mc_tlsbase =
    203 		(uintptr_t) ptr;
    204 	pcb->pcb_ucp.uc_flags |= _UC_TLSBASE;
    205 
    206 	pcb->pcb_userret_ucp.uc_mcontext._mc_tlsbase =
    207 		(uintptr_t) ptr;
    208 	pcb->pcb_userret_ucp.uc_flags |= _UC_TLSBASE;
    209 
    210 	return 0;
    211 }
    212 
    213 static
    214 void
    215 cpu_switchto_atomic(lwp_t *oldlwp, lwp_t *newlwp)
    216 {
    217 	struct pcb *oldpcb;
    218 	struct pcb *newpcb;
    219 	struct cpu_info *ci;
    220 	int s;
    221 
    222 	oldpcb = oldlwp ? lwp_getpcb(oldlwp) : NULL;
    223 	newpcb = lwp_getpcb(newlwp);
    224 	ci = curcpu();
    225 
    226 	s = splhigh();
    227 
    228 	ci->ci_stash = oldlwp;
    229 	if (oldpcb)
    230 		oldpcb->pcb_errno = thunk_geterrno();
    231 
    232 	thunk_seterrno(newpcb->pcb_errno);
    233 	curlwp = newlwp;
    234 
    235 	splx(s);
    236 
    237 	if (thunk_setcontext(&newpcb->pcb_ucp))
    238 		panic("setcontext failed");
    239 
    240 	/* not reached */
    241 }
    242 
    243 
    244 lwp_t *
    245 cpu_switchto(lwp_t *oldlwp, lwp_t *newlwp, bool returning)
    246 {
    247 	struct pcb *oldpcb = oldlwp ? lwp_getpcb(oldlwp) : NULL;
    248 	struct pcb *newpcb = lwp_getpcb(newlwp);
    249 	struct cpu_info *ci = curcpu();
    250 	cpu_softc_t *sc = device_private(ci->ci_dev);
    251 
    252 #ifdef CPU_DEBUG
    253 	thunk_printf_debug("cpu_switchto [%s,pid=%d,lid=%d] -> [%s,pid=%d,lid=%d]\n",
    254 	    oldlwp ? oldlwp->l_name : "none",
    255 	    oldlwp ? oldlwp->l_proc->p_pid : -1,
    256 	    oldlwp ? oldlwp->l_lid : -1,
    257 	    newlwp ? newlwp->l_name : "none",
    258 	    newlwp ? newlwp->l_proc->p_pid : -1,
    259 	    newlwp ? newlwp->l_lid : -1);
    260 	if (oldpcb) {
    261 		thunk_printf_debug("    oldpcb uc_link=%p, uc_stack.ss_sp=%p, "
    262 		    "uc_stack.ss_size=%d, l_private %p, uc_mcontext._mc_tlsbase=%p(%s)\n",
    263 		    oldpcb->pcb_ucp.uc_link,
    264 		    oldpcb->pcb_ucp.uc_stack.ss_sp,
    265 		    (int)oldpcb->pcb_ucp.uc_stack.ss_size,
    266 		    (void *) oldlwp->l_private,
    267 		    (void *) oldpcb->pcb_ucp.uc_mcontext._mc_tlsbase,
    268 		    oldpcb->pcb_ucp.uc_flags & _UC_TLSBASE? "ON":"off");
    269 	}
    270 	if (newpcb) {
    271 		thunk_printf_debug("    newpewcb uc_link=%p, uc_stack.ss_sp=%p, "
    272 		    "uc_stack.ss_size=%d, l_private %p, uc_mcontext._mc_tlsbase=%p(%s)\n",
    273 		    newpcb->pcb_ucp.uc_link,
    274 		    newpcb->pcb_ucp.uc_stack.ss_sp,
    275 		    (int)newpcb->pcb_ucp.uc_stack.ss_size,
    276 		    (void *) newlwp->l_private,
    277 		    (void *) newpcb->pcb_ucp.uc_mcontext._mc_tlsbase,
    278 		    newpcb->pcb_ucp.uc_flags & _UC_TLSBASE? "ON":"off");
    279 	}
    280 #endif /* !CPU_DEBUG */
    281 
    282 	/* create atomic switcher */
    283 	KASSERT(newlwp);
    284 	thunk_makecontext(&sc->sc_ucp, (void (*)(void)) cpu_switchto_atomic,
    285 			2, oldlwp, newlwp, NULL, NULL);
    286 	KASSERT(sc);
    287 	if (oldpcb) {
    288 		thunk_swapcontext(&oldpcb->pcb_ucp, &sc->sc_ucp);
    289 		/* returns here */
    290 	} else {
    291 		thunk_setcontext(&sc->sc_ucp);
    292 		/* never returns */
    293 	}
    294 
    295 #ifdef CPU_DEBUG
    296 	thunk_printf_debug("cpu_switchto: returning %p (was %p)\n", ci->ci_stash, oldlwp);
    297 #endif
    298 	return ci->ci_stash;
    299 }
    300 
    301 void
    302 cpu_dumpconf(void)
    303 {
    304 #ifdef CPU_DEBUG
    305 	thunk_printf_debug("cpu_dumpconf\n");
    306 #endif
    307 }
    308 
    309 void
    310 cpu_signotify(struct lwp *l)
    311 {
    312 }
    313 
    314 void
    315 cpu_getmcontext(struct lwp *l, mcontext_t *mcp, unsigned int *flags)
    316 {
    317 	struct pcb *pcb = lwp_getpcb(l);
    318 	ucontext_t *ucp = &pcb->pcb_userret_ucp;
    319 
    320 #ifdef CPU_DEBUG
    321 	thunk_printf_debug("cpu_getmcontext\n");
    322 #endif
    323 	memcpy(mcp, &ucp->uc_mcontext, sizeof(mcontext_t));
    324 
    325 	/* XXX be overzealous and provide all */
    326 	mcp->_mc_tlsbase = (uintptr_t) l->l_private;
    327 	*flags = _UC_CPU | _UC_STACK | _UC_SIGMASK | _UC_FPU | _UC_TLSBASE;
    328 
    329 	return;
    330 }
    331 
    332 int
    333 cpu_mcontext_validate(struct lwp *l, const mcontext_t *mcp)
    334 {
    335 	/*
    336 	 * can we check here? or should that be done in the target
    337 	 * specific places?
    338 	 */
    339 	/* XXX NO CHECKING! XXX */
    340 #ifdef CPU_DEBUG
    341 	thunk_printf("cpu_mcontext_validate\n");
    342 #endif
    343 	return 0;
    344 }
    345 
    346 int
    347 cpu_setmcontext(struct lwp *l, const mcontext_t *mcp, unsigned int flags)
    348 {
    349 	struct pcb *pcb = lwp_getpcb(l);
    350 	ucontext_t *ucp = &pcb->pcb_userret_ucp;
    351 
    352 #ifdef CPU_DEBUG
    353 	thunk_printf_debug("cpu_setmcontext\n");
    354 #endif
    355 	if ((flags & _UC_CPU) != 0)
    356 		memcpy(&ucp->uc_mcontext.__gregs, mcp->__gregs, sizeof(__gregset_t));
    357 	if ((flags & _UC_FPU) != 0)
    358 		memcpy(&ucp->uc_mcontext.__fpregs, mcp->__fpregs, sizeof(__fpregset_t));
    359 	if ((flags & _UC_TLSBASE) != 0)
    360 		lwp_setprivate(l, (void *) (uintptr_t) mcp->_mc_tlsbase);
    361 
    362 #if 0
    363 	/*
    364 	 * XXX we ignore the set and clear stack since signals are done
    365 	 * slightly differently.
    366 	 */
    367 thunk_printf("%s: flags %x\n", __func__, flags);
    368 	mutex_enter(l->l_proc->p_lock);
    369 	if (flags & _UC_SETSTACK)
    370 		l->l_sigstk.ss_flags |= SS_ONSTACK;
    371 	if (flags & _UC_CLRSTACK)
    372 		l->l_sigstk.ss_flags &= ~SS_ONSTACK;
    373 	mutex_exit(l->l_proc->p_lock);
    374 #endif
    375 
    376 	ucp->uc_flags |= (flags & (_UC_CPU | _UC_FPU | _UC_TLSBASE));
    377 
    378 	return 0;
    379 }
    380 
    381 void
    382 cpu_idle(void)
    383 {
    384 	struct cpu_info *ci = curcpu();
    385 
    386 	if (ci->ci_want_resched)
    387 		return;
    388 
    389 	thunk_idle();
    390 }
    391 
    392 void
    393 cpu_lwp_free(struct lwp *l, int proc)
    394 {
    395 #ifdef CPU_DEBUG
    396 	thunk_printf_debug("cpu_lwp_free (dummy)\n");
    397 #endif
    398 }
    399 
    400 void
    401 cpu_lwp_free2(struct lwp *l)
    402 {
    403 	struct pcb *pcb = lwp_getpcb(l);
    404 
    405 #ifdef CPU_DEBUG
    406 	thunk_printf_debug("cpu_lwp_free2\n");
    407 #endif
    408 
    409 	if (pcb == NULL)
    410 		return;
    411 	/* XXX nothing to do? */
    412 }
    413 
    414 static void
    415 cpu_lwp_trampoline(ucontext_t *ucp, void (*func)(void *), void *arg)
    416 {
    417 #ifdef CPU_DEBUG
    418 	thunk_printf_debug("cpu_lwp_trampoline called with func %p, arg %p\n", (void *) func, arg);
    419 #endif
    420 	/* init lwp */
    421 	lwp_startup(curcpu()->ci_stash, curlwp);
    422 
    423 	/* actual jump */
    424 	thunk_makecontext(ucp, (void (*)(void)) func, 1, arg, NULL, NULL, NULL);
    425 	thunk_setcontext(ucp);
    426 }
    427 
    428 void
    429 cpu_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize,
    430     void (*func)(void *), void *arg)
    431 {
    432 	struct pcb *pcb1 = lwp_getpcb(l1);
    433 	struct pcb *pcb2 = lwp_getpcb(l2);
    434 
    435 #ifdef CPU_DEBUG
    436 	thunk_printf_debug("cpu_lwp_fork [%s/%p] -> [%s/%p] stack=%p stacksize=%d\n",
    437 	    l1 ? l1->l_name : "none", l1,
    438 	    l2 ? l2->l_name : "none", l2,
    439 	    stack, (int)stacksize);
    440 #endif
    441 	if (stack)
    442 		panic("%s: stack passed, can't handle\n", __func__);
    443 
    444 	/* copy the PCB and its switchframes from parent */
    445 	memcpy(pcb2, pcb1, sizeof(struct pcb));
    446 
    447 	/* refresh context, XXX needed? */
    448 	if (thunk_getcontext(&pcb2->pcb_ucp))
    449 		panic("getcontext failed");
    450 
    451 	/* set up for TLS */
    452 	pcb2->pcb_ucp.uc_mcontext._mc_tlsbase = (intptr_t) l2->l_private;
    453 	pcb2->pcb_ucp.uc_flags |= _UC_TLSBASE;
    454 
    455 	/* recalculate the system stack top */
    456 	pcb2->sys_stack_top = pcb2->sys_stack + TRAPSTACKSIZE;
    457 
    458 	/* get l2 its own stack */
    459 	pcb2->pcb_ucp.uc_stack.ss_sp = pcb2->sys_stack;
    460 	pcb2->pcb_ucp.uc_stack.ss_size = pcb2->sys_stack_top - pcb2->sys_stack;
    461 	pcb2->pcb_ucp.uc_link = &pcb2->pcb_userret_ucp;
    462 
    463 	thunk_sigemptyset(&pcb2->pcb_ucp.uc_sigmask);
    464 
    465 	thunk_makecontext(&pcb2->pcb_ucp,
    466 	    (void (*)(void)) cpu_lwp_trampoline,
    467 	    3, &pcb2->pcb_ucp, func, arg, NULL);
    468 }
    469 
    470 void
    471 cpu_initclocks(void)
    472 {
    473 	extern timer_t clock_timerid;
    474 
    475 	thunk_timer_start(clock_timerid, HZ);
    476 }
    477 
    478 void
    479 cpu_startup(void)
    480 {
    481 	vaddr_t minaddr, maxaddr;
    482 	size_t msgbufsize = 32 * 1024;
    483 
    484 	/* get ourself a message buffer */
    485 	um_msgbuf = kmem_zalloc(msgbufsize, KM_SLEEP);
    486 	initmsgbuf(um_msgbuf, msgbufsize);
    487 
    488 	/* allocate a submap for physio, 1Mb enough? */
    489 	minaddr = 0;
    490 	phys_map = uvm_km_suballoc(kernel_map, &minaddr, &maxaddr,
    491 				   1024 * 1024, 0, false, NULL);
    492 
    493 	/* say hi! */
    494 	banner();
    495 
    496 	/* init lwp0 */
    497 	memset(&lwp0pcb, 0, sizeof(lwp0pcb));
    498 	thunk_getcontext(&lwp0pcb.pcb_ucp);
    499 	thunk_sigemptyset(&lwp0pcb.pcb_ucp.uc_sigmask);
    500 	lwp0pcb.pcb_ucp.uc_flags = _UC_STACK | _UC_CPU | _UC_SIGMASK;
    501 
    502 	uvm_lwp_setuarea(&lwp0, (vaddr_t) &lwp0pcb);
    503 	memcpy(&lwp0pcb.pcb_userret_ucp, &lwp0pcb.pcb_ucp, sizeof(ucontext_t));
    504 
    505 	/* set stack top */
    506 	lwp0pcb.sys_stack_top = lwp0pcb.sys_stack + TRAPSTACKSIZE;
    507 }
    508 
    509 void
    510 cpu_rootconf(void)
    511 {
    512 	extern char *usermode_root_device;
    513 	device_t rdev;
    514 
    515 	if (usermode_root_device != NULL) {
    516 		rdev = device_find_by_xname(usermode_root_device);
    517 	} else {
    518 		rdev = device_find_by_xname("ld0");
    519 		if (rdev == NULL)
    520 			rdev = device_find_by_xname("md0");
    521 	}
    522 
    523 	aprint_normal("boot device: %s\n",
    524 	    rdev ? device_xname(rdev) : "<unknown>");
    525 	booted_device = rdev;
    526 	rootconf();
    527 }
    528 
    529 bool
    530 cpu_intr_p(void)
    531 {
    532 	int idepth;
    533 
    534 	kpreempt_disable();
    535 	idepth = curcpu()->ci_idepth;
    536 	kpreempt_enable();
    537 
    538 	return (idepth >= 0);
    539 }
    540