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cpu.c revision 1.74.8.1 
      1 /* $NetBSD: cpu.c,v 1.74.8.1 2018/05/21 04:36:02 pgoyette 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 1.74.8.1 2018/05/21 04:36:02 pgoyette 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 struct cpu_info cpu_info_primary = {
     70 	.ci_dev = 0,
     71 	.ci_self = &cpu_info_primary,
     72 	.ci_idepth = -1,
     73 	.ci_curlwp = &lwp0,
     74 };
     75 
     76 typedef struct cpu_softc {
     77 	device_t	sc_dev;
     78 	struct cpu_info	*sc_ci;
     79 
     80 	ucontext_t	sc_ucp;
     81 	uint8_t		sc_ucp_stack[PAGE_SIZE];
     82 } cpu_softc_t;
     83 
     84 
     85 /* statics */
     86 static struct pcb lwp0pcb;
     87 static void *um_msgbuf;
     88 
     89 
     90 /* attachment */
     91 CFATTACH_DECL_NEW(cpu, sizeof(cpu_softc_t), cpu_match, cpu_attach, NULL, NULL);
     92 
     93 static int
     94 cpu_match(device_t parent, cfdata_t match, void *opaque)
     95 {
     96 	struct thunkbus_attach_args *taa = opaque;
     97 
     98 	if (taa->taa_type != THUNKBUS_TYPE_CPU)
     99 		return 0;
    100 
    101 	return 1;
    102 }
    103 
    104 static void
    105 cpu_attach(device_t parent, device_t self, void *opaque)
    106 {
    107 	cpu_softc_t *sc = device_private(self);
    108 
    109 	aprint_naive("\n");
    110 	aprint_normal("\n");
    111 
    112 	cpu_info_primary.ci_dev = self;
    113 	sc->sc_dev = self;
    114 	sc->sc_ci = &cpu_info_primary;
    115 
    116 	thunk_getcontext(&sc->sc_ucp);
    117 	sc->sc_ucp.uc_stack.ss_sp = sc->sc_ucp_stack;
    118 	sc->sc_ucp.uc_stack.ss_size = PAGE_SIZE - sizeof(register_t);
    119 	sc->sc_ucp.uc_flags = _UC_STACK | _UC_CPU | _UC_SIGMASK;
    120 	thunk_sigaddset(&sc->sc_ucp.uc_sigmask, SIGALRM);
    121 	thunk_sigaddset(&sc->sc_ucp.uc_sigmask, SIGIO);
    122 	thunk_sigaddset(&sc->sc_ucp.uc_sigmask, SIGINT);
    123 	thunk_sigaddset(&sc->sc_ucp.uc_sigmask, SIGTSTP);
    124 }
    125 
    126 void
    127 cpu_configure(void)
    128 {
    129 	cpu_setmodel("virtual processor");
    130 	if (config_rootfound("mainbus", NULL) == NULL)
    131 		panic("configure: mainbus not configured");
    132 
    133 
    134 	spl0();
    135 }
    136 
    137 
    138 /* main guts */
    139 void
    140 cpu_reboot(int howto, char *bootstr)
    141 {
    142 	extern void usermode_reboot(void);
    143 
    144 	if (cold)
    145 		howto |= RB_HALT;
    146 
    147 	if ((howto & RB_NOSYNC) == 0)
    148 		vfs_shutdown();
    149 	else
    150 		suspendsched();
    151 
    152 	doshutdownhooks();
    153 	pmf_system_shutdown(boothowto);
    154 
    155 	if ((howto & RB_POWERDOWN) == RB_POWERDOWN)
    156 		thunk_exit(0);
    157 
    158 	splhigh();
    159 
    160 	if (howto & RB_DUMP)
    161 		thunk_abort();
    162 
    163 	if (howto & RB_HALT) {
    164 		printf("\n");
    165 		printf("The operating system has halted.\n");
    166 		printf("Please press any key to reboot.\n\n");
    167 		cnpollc(1);
    168 		cngetc();
    169 		cnpollc(0);
    170 	}
    171 
    172 	printf("rebooting...\n");
    173 
    174 	usermode_reboot();
    175 
    176 	/* NOTREACHED */
    177 	cpu_unreachable();
    178 }
    179 
    180 void
    181 cpu_need_resched(struct cpu_info *ci, int flags)
    182 {
    183 	ci->ci_want_resched |= flags;
    184 	aston(ci);
    185 }
    186 
    187 void
    188 cpu_need_proftick(struct lwp *l)
    189 {
    190 }
    191 
    192 static
    193 void
    194 cpu_switchto_atomic(lwp_t *oldlwp, lwp_t *newlwp)
    195 {
    196 	struct pcb *oldpcb;
    197 	struct pcb *newpcb;
    198 	struct cpu_info *ci;
    199 
    200 	oldpcb = oldlwp ? lwp_getpcb(oldlwp) : NULL;
    201 	newpcb = lwp_getpcb(newlwp);
    202 	ci = curcpu();
    203 
    204 	ci->ci_stash = oldlwp;
    205 
    206 	if (oldpcb)
    207 		oldpcb->pcb_errno = thunk_geterrno();
    208 
    209 	thunk_seterrno(newpcb->pcb_errno);
    210 
    211 	curlwp = newlwp;
    212 	if (thunk_setcontext(&newpcb->pcb_ucp))
    213 		panic("setcontext failed");
    214 	/* not reached */
    215 }
    216 
    217 lwp_t *
    218 cpu_switchto(lwp_t *oldlwp, lwp_t *newlwp, bool returning)
    219 {
    220 	struct pcb *oldpcb = oldlwp ? lwp_getpcb(oldlwp) : NULL;
    221 	struct pcb *newpcb = lwp_getpcb(newlwp);
    222 	struct cpu_info *ci = curcpu();
    223 	cpu_softc_t *sc = device_private(ci->ci_dev);
    224 
    225 #ifdef CPU_DEBUG
    226 	thunk_printf_debug("cpu_switchto [%s,pid=%d,lid=%d] -> [%s,pid=%d,lid=%d]\n",
    227 	    oldlwp ? oldlwp->l_name : "none",
    228 	    oldlwp ? oldlwp->l_proc->p_pid : -1,
    229 	    oldlwp ? oldlwp->l_lid : -1,
    230 	    newlwp ? newlwp->l_name : "none",
    231 	    newlwp ? newlwp->l_proc->p_pid : -1,
    232 	    newlwp ? newlwp->l_lid : -1);
    233 	if (oldpcb) {
    234 		thunk_printf_debug("    oldpcb uc_link=%p, uc_stack.ss_sp=%p, "
    235 		    "uc_stack.ss_size=%d\n",
    236 		    oldpcb->pcb_ucp.uc_link,
    237 		    oldpcb->pcb_ucp.uc_stack.ss_sp,
    238 		    (int)oldpcb->pcb_ucp.uc_stack.ss_size);
    239 	}
    240 	if (newpcb) {
    241 		thunk_printf_debug("    newpcb uc_link=%p, uc_stack.ss_sp=%p, "
    242 		    "uc_stack.ss_size=%d\n",
    243 		    newpcb->pcb_ucp.uc_link,
    244 		    newpcb->pcb_ucp.uc_stack.ss_sp,
    245 		    (int)newpcb->pcb_ucp.uc_stack.ss_size);
    246 	}
    247 #endif /* !CPU_DEBUG */
    248 
    249 	/* create atomic switcher */
    250 	KASSERT(newlwp);
    251 	thunk_makecontext(&sc->sc_ucp, (void (*)(void)) cpu_switchto_atomic,
    252 			2, oldlwp, newlwp, NULL, NULL);
    253 
    254 	KASSERT(sc);
    255 	if (oldpcb) {
    256 		thunk_swapcontext(&oldpcb->pcb_ucp, &sc->sc_ucp);
    257 		/* returns here */
    258 	} else {
    259 		thunk_setcontext(&sc->sc_ucp);
    260 		/* never returns */
    261 	}
    262 
    263 #ifdef CPU_DEBUG
    264 	thunk_printf_debug("cpu_switchto: returning %p (was %p)\n", ci->ci_stash, oldlwp);
    265 #endif
    266 	return ci->ci_stash;
    267 }
    268 
    269 void
    270 cpu_dumpconf(void)
    271 {
    272 #ifdef CPU_DEBUG
    273 	thunk_printf_debug("cpu_dumpconf\n");
    274 #endif
    275 }
    276 
    277 void
    278 cpu_signotify(struct lwp *l)
    279 {
    280 }
    281 
    282 void
    283 cpu_getmcontext(struct lwp *l, mcontext_t *mcp, unsigned int *flags)
    284 {
    285 	struct pcb *pcb = lwp_getpcb(l);
    286 	ucontext_t *ucp = &pcb->pcb_userret_ucp;
    287 
    288 #ifdef CPU_DEBUG
    289 	thunk_printf_debug("cpu_getmcontext\n");
    290 #endif
    291 	memcpy(mcp, &ucp->uc_mcontext, sizeof(mcontext_t));
    292 	return;
    293 }
    294 
    295 int
    296 cpu_mcontext_validate(struct lwp *l, const mcontext_t *mcp)
    297 {
    298 	/*
    299 	 * can we check here? or should that be done in the target
    300 	 * specific places?
    301 	 */
    302 	return 0;
    303 }
    304 
    305 int
    306 cpu_setmcontext(struct lwp *l, const mcontext_t *mcp, unsigned int flags)
    307 {
    308 	struct pcb *pcb = lwp_getpcb(l);
    309 	ucontext_t *ucp = &pcb->pcb_userret_ucp;
    310 
    311 #ifdef CPU_DEBUG
    312 	thunk_printf_debug("cpu_setmcontext\n");
    313 #endif
    314 	memcpy(&ucp->uc_mcontext, mcp, sizeof(mcontext_t));
    315 	return 0;
    316 }
    317 
    318 void
    319 cpu_idle(void)
    320 {
    321 	struct cpu_info *ci = curcpu();
    322 
    323 	if (ci->ci_want_resched)
    324 		return;
    325 
    326 	thunk_idle();
    327 }
    328 
    329 void
    330 cpu_lwp_free(struct lwp *l, int proc)
    331 {
    332 #ifdef CPU_DEBUG
    333 	thunk_printf_debug("cpu_lwp_free (dummy)\n");
    334 #endif
    335 }
    336 
    337 void
    338 cpu_lwp_free2(struct lwp *l)
    339 {
    340 	struct pcb *pcb = lwp_getpcb(l);
    341 
    342 #ifdef CPU_DEBUG
    343 	thunk_printf_debug("cpu_lwp_free2\n");
    344 #endif
    345 
    346 	if (pcb == NULL)
    347 		return;
    348 	/* XXX nothing to do? */
    349 }
    350 
    351 static void
    352 cpu_lwp_trampoline(ucontext_t *ucp, void (*func)(void *), void *arg)
    353 {
    354 #ifdef CPU_DEBUG
    355 	thunk_printf_debug("cpu_lwp_trampoline called with func %p, arg %p\n", (void *) func, arg);
    356 #endif
    357 	/* init lwp */
    358 	lwp_startup(curcpu()->ci_stash, curlwp);
    359 
    360 	/* actual jump */
    361 	thunk_makecontext(ucp, (void (*)(void)) func, 1, arg, NULL, NULL, NULL);
    362 	thunk_setcontext(ucp);
    363 }
    364 
    365 void
    366 cpu_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize,
    367     void (*func)(void *), void *arg)
    368 {
    369 	struct pcb *pcb1 = lwp_getpcb(l1);
    370 	struct pcb *pcb2 = lwp_getpcb(l2);
    371 
    372 #ifdef CPU_DEBUG
    373 	thunk_printf_debug("cpu_lwp_fork [%s/%p] -> [%s/%p] stack=%p stacksize=%d\n",
    374 	    l1 ? l1->l_name : "none", l1,
    375 	    l2 ? l2->l_name : "none", l2,
    376 	    stack, (int)stacksize);
    377 #endif
    378 
    379 	if (stack)
    380 		panic("%s: stack passed, can't handle\n", __func__);
    381 
    382 	/* copy the PCB and its switchframes from parent */
    383 	memcpy(pcb2, pcb1, sizeof(struct pcb));
    384 
    385 	/* refresh context */
    386 	if (thunk_getcontext(&pcb2->pcb_ucp))
    387 		panic("getcontext failed");
    388 
    389 	/* recalculate the system stack top */
    390 	pcb2->sys_stack_top = pcb2->sys_stack + TRAPSTACKSIZE;
    391 
    392 	/* get l2 its own stack */
    393 	pcb2->pcb_ucp.uc_stack.ss_sp = pcb2->sys_stack;
    394 	pcb2->pcb_ucp.uc_stack.ss_size = pcb2->sys_stack_top - pcb2->sys_stack;
    395 	pcb2->pcb_ucp.uc_link = &pcb2->pcb_userret_ucp;
    396 
    397 	thunk_sigemptyset(&pcb2->pcb_ucp.uc_sigmask);
    398 	pcb2->pcb_ucp.uc_flags = _UC_STACK | _UC_CPU | _UC_SIGMASK;
    399 	thunk_makecontext(&pcb2->pcb_ucp,
    400 	    (void (*)(void)) cpu_lwp_trampoline,
    401 	    3, &pcb2->pcb_ucp, func, arg, NULL);
    402 }
    403 
    404 void
    405 cpu_initclocks(void)
    406 {
    407 	extern timer_t clock_timerid;
    408 
    409 	thunk_timer_start(clock_timerid, HZ);
    410 }
    411 
    412 void
    413 cpu_startup(void)
    414 {
    415 	vaddr_t minaddr, maxaddr;
    416 	size_t msgbufsize = 32 * 1024;
    417 
    418 	/* get ourself a message buffer */
    419 	um_msgbuf = kmem_zalloc(msgbufsize, KM_SLEEP);
    420 	initmsgbuf(um_msgbuf, msgbufsize);
    421 
    422 	/* allocate a submap for physio, 1Mb enough? */
    423 	minaddr = 0;
    424 	phys_map = uvm_km_suballoc(kernel_map, &minaddr, &maxaddr,
    425 				   1024 * 1024, 0, false, NULL);
    426 
    427 	/* say hi! */
    428 	banner();
    429 
    430 	/* init lwp0 */
    431 	memset(&lwp0pcb, 0, sizeof(lwp0pcb));
    432 	thunk_getcontext(&lwp0pcb.pcb_ucp);
    433 	thunk_sigemptyset(&lwp0pcb.pcb_ucp.uc_sigmask);
    434 	lwp0pcb.pcb_ucp.uc_flags = _UC_STACK | _UC_CPU | _UC_SIGMASK;
    435 
    436 	uvm_lwp_setuarea(&lwp0, (vaddr_t) &lwp0pcb);
    437 	memcpy(&lwp0pcb.pcb_userret_ucp, &lwp0pcb.pcb_ucp, sizeof(ucontext_t));
    438 
    439 	/* set stack top */
    440 	lwp0pcb.sys_stack_top = lwp0pcb.sys_stack + TRAPSTACKSIZE;
    441 }
    442 
    443 void
    444 cpu_rootconf(void)
    445 {
    446 	extern char *usermode_root_device;
    447 	device_t rdev;
    448 
    449 	if (usermode_root_device != NULL) {
    450 		rdev = device_find_by_xname(usermode_root_device);
    451 	} else {
    452 		rdev = device_find_by_xname("ld0");
    453 		if (rdev == NULL)
    454 			rdev = device_find_by_xname("md0");
    455 	}
    456 
    457 	aprint_normal("boot device: %s\n",
    458 	    rdev ? device_xname(rdev) : "<unknown>");
    459 	booted_device = rdev;
    460 	rootconf();
    461 }
    462 
    463 bool
    464 cpu_intr_p(void)
    465 {
    466 	int idepth;
    467 
    468 	kpreempt_disable();
    469 	idepth = curcpu()->ci_idepth;
    470 	kpreempt_enable();
    471 
    472 	return (idepth >= 0);
    473 }
    474