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cpu.c revision 1.38 
      1 /* $NetBSD: cpu.c,v 1.38 2011/09/08 12:37:28 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 1.38 2011/09/08 12:37:28 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 
     46 #include <dev/cons.h>
     47 
     48 #include <machine/cpu.h>
     49 #include <machine/mainbus.h>
     50 #include <machine/pcb.h>
     51 #include <machine/thunk.h>
     52 
     53 #include <uvm/uvm_extern.h>
     54 #include <uvm/uvm_page.h>
     55 
     56 #if __GNUC_PREREQ__(4,4)
     57 #define cpu_unreachable()	__builtin_unreachable()
     58 #else
     59 #define cpu_unreachable()	do { thunk_abort(); } while (0)
     60 #endif
     61 
     62 static int	cpu_match(device_t, cfdata_t, void *);
     63 static void	cpu_attach(device_t, device_t, void *);
     64 
     65 struct cpu_info cpu_info_primary = {
     66 	.ci_dev = 0,
     67 	.ci_self = &cpu_info_primary,
     68 	.ci_idepth = -1,
     69 	.ci_curlwp = &lwp0,
     70 };
     71 
     72 char cpu_model[48] = "virtual processor";
     73 
     74 typedef struct cpu_softc {
     75 	device_t	sc_dev;
     76 	struct cpu_info	*sc_ci;
     77 } cpu_softc_t;
     78 
     79 static struct pcb lwp0pcb;
     80 static void *msgbuf;
     81 
     82 CFATTACH_DECL_NEW(cpu, sizeof(cpu_softc_t), cpu_match, cpu_attach, NULL, NULL);
     83 
     84 static int
     85 cpu_match(device_t parent, cfdata_t match, void *opaque)
     86 {
     87 	struct thunkbus_attach_args *taa = opaque;
     88 
     89 	if (taa->taa_type != THUNKBUS_TYPE_CPU)
     90 		return 0;
     91 
     92 	return 1;
     93 }
     94 
     95 static void
     96 cpu_attach(device_t parent, device_t self, void *opaque)
     97 {
     98 	cpu_softc_t *sc = device_private(self);
     99 
    100 	aprint_naive("\n");
    101 	aprint_normal("\n");
    102 
    103 	sc->sc_dev = self;
    104 	sc->sc_ci = &cpu_info_primary;
    105 }
    106 
    107 void
    108 cpu_configure(void)
    109 {
    110 	if (config_rootfound("mainbus", NULL) == NULL)
    111 		panic("configure: mainbus not configured");
    112 
    113 	spl0();
    114 }
    115 
    116 void
    117 cpu_reboot(int howto, char *bootstr)
    118 {
    119 	extern void usermode_reboot(void);
    120 
    121 	splhigh();
    122 
    123 	if ((howto & RB_POWERDOWN) == RB_POWERDOWN)
    124 		thunk_exit(0);
    125 
    126 	if (howto & RB_DUMP)
    127 		thunk_abort();
    128 
    129 	if (howto & RB_HALT) {
    130 		printf("\n");
    131 		printf("The operating system has halted.\n");
    132 		printf("Please press any key to reboot.\n\n");
    133 		cnpollc(1);
    134 		cngetc();
    135 		cnpollc(0);
    136 	}
    137 
    138 	printf("rebooting...\n");
    139 
    140 	usermode_reboot();
    141 
    142 	/* NOTREACHED */
    143 	cpu_unreachable();
    144 }
    145 
    146 void
    147 cpu_need_resched(struct cpu_info *ci, int flags)
    148 {
    149 	ci->ci_want_resched |= flags;
    150 }
    151 
    152 void
    153 cpu_need_proftick(struct lwp *l)
    154 {
    155 }
    156 
    157 lwp_t *
    158 cpu_switchto(lwp_t *oldlwp, lwp_t *newlwp, bool returning)
    159 {
    160 	struct pcb *oldpcb = oldlwp ? lwp_getpcb(oldlwp) : NULL;
    161 	struct pcb *newpcb = lwp_getpcb(newlwp);
    162 	struct cpu_info *ci = curcpu();
    163 
    164 #ifdef CPU_DEBUG
    165 	printf("cpu_switchto [%s,pid=%d,lid=%d] -> [%s,pid=%d,lid=%d]\n",
    166 	    oldlwp ? oldlwp->l_name : "none",
    167 	    oldlwp ? oldlwp->l_proc->p_pid : -1,
    168 	    oldlwp ? oldlwp->l_lid : -1,
    169 	    newlwp ? newlwp->l_name : "none",
    170 	    newlwp ? newlwp->l_proc->p_pid : -1,
    171 	    newlwp ? newlwp->l_lid : -1);
    172 	if (oldpcb) {
    173 		printf("    oldpcb uc_link=%p, uc_stack.ss_sp=%p, "
    174 		    "uc_stack.ss_size=%d\n",
    175 		    oldpcb->pcb_ucp.uc_link,
    176 		    oldpcb->pcb_ucp.uc_stack.ss_sp,
    177 		    (int)oldpcb->pcb_ucp.uc_stack.ss_size);
    178 	}
    179 	if (newpcb) {
    180 		printf("    newpcb uc_link=%p, uc_stack.ss_sp=%p, "
    181 		    "uc_stack.ss_size=%d\n",
    182 		    newpcb->pcb_ucp.uc_link,
    183 		    newpcb->pcb_ucp.uc_stack.ss_sp,
    184 		    (int)newpcb->pcb_ucp.uc_stack.ss_size);
    185 	}
    186 #endif /* !CPU_DEBUG */
    187 
    188 	ci->ci_stash = oldlwp;
    189 	curlwp = newlwp;
    190 
    191 	if (oldpcb) {
    192 		oldpcb->pcb_errno = thunk_geterrno();
    193 		thunk_seterrno(newpcb->pcb_errno);
    194 		if (thunk_swapcontext(&oldpcb->pcb_ucp, &newpcb->pcb_ucp))
    195 			panic("swapcontext failed");
    196 	} else {
    197 		thunk_seterrno(newpcb->pcb_errno);
    198 		if (thunk_setcontext(&newpcb->pcb_ucp))
    199 			panic("setcontext failed");
    200 	}
    201 
    202 #ifdef CPU_DEBUG
    203 	printf("cpu_switchto: returning %p (was %p)\n", ci->ci_stash, oldlwp);
    204 #endif
    205 	return ci->ci_stash;
    206 }
    207 
    208 void
    209 cpu_dumpconf(void)
    210 {
    211 #ifdef CPU_DEBUG
    212 	printf("cpu_dumpconf\n");
    213 #endif
    214 }
    215 
    216 void
    217 cpu_signotify(struct lwp *l)
    218 {
    219 }
    220 
    221 void
    222 cpu_getmcontext(struct lwp *l, mcontext_t *mcp, unsigned int *flags)
    223 {
    224 #ifdef CPU_DEBUG
    225 	printf("cpu_getmcontext\n");
    226 #endif
    227 }
    228 
    229 int
    230 cpu_setmcontext(struct lwp *l, const mcontext_t *mcp, unsigned int flags)
    231 {
    232 #ifdef CPU_DEBUG
    233 	printf("cpu_setmcontext\n");
    234 #endif
    235 	return 0;
    236 }
    237 
    238 void
    239 cpu_idle(void)
    240 {
    241 	struct cpu_info *ci = curcpu();
    242 
    243 	if (ci->ci_want_resched)
    244 		return;
    245 
    246 #if notyet
    247 	thunk_usleep(10000);
    248 #endif
    249 }
    250 
    251 void
    252 cpu_lwp_free(struct lwp *l, int proc)
    253 {
    254 #ifdef CPU_DEBUG
    255 	printf("cpu_lwp_free\n");
    256 #endif
    257 }
    258 
    259 void
    260 cpu_lwp_free2(struct lwp *l)
    261 {
    262 	struct pcb *pcb = lwp_getpcb(l);
    263 
    264 #ifdef CPU_DEBUG
    265 	printf("cpu_lwp_free2\n");
    266 #endif
    267 
    268 	if (pcb == NULL)
    269 		return;
    270 
    271 	if (pcb->pcb_needfree) {
    272 		free(pcb->pcb_ucp.uc_stack.ss_sp, M_TEMP);
    273 		pcb->pcb_ucp.uc_stack.ss_sp = NULL;
    274 		pcb->pcb_ucp.uc_stack.ss_size = 0;
    275 		pcb->pcb_needfree = false;
    276 	}
    277 }
    278 
    279 static void
    280 cpu_lwp_trampoline(void (*func)(void *), void *arg)
    281 {
    282 	struct pcb *pcb;
    283 
    284 #ifdef CPU_DEBUG
    285 	printf("cpu_lwp_trampoline called with func %p, arg %p\n", (void *) func, arg);
    286 #endif
    287 	lwp_startup(curcpu()->ci_stash, curlwp);
    288 
    289 	func(arg);
    290 
    291 	pcb = lwp_getpcb(curlwp);
    292 
    293 	/* switch to userland */
    294 printf("switching to userland\n");
    295 	thunk_setcontext(&pcb->pcb_userland_ucp);
    296 
    297 	panic("%s: shouldn't return", __func__);
    298 }
    299 
    300 extern int syscall(lwp_t *l);
    301 void
    302 cpu_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize,
    303     void (*func)(void *), void *arg)
    304 {
    305 	struct pcb *pcb1 = lwp_getpcb(l1);
    306 	struct pcb *pcb2 = lwp_getpcb(l2);
    307 
    308 #ifdef CPU_DEBUG
    309 	printf("cpu_lwp_fork [%s/%p] -> [%s/%p] stack=%p stacksize=%d\n",
    310 	    l1 ? l1->l_name : "none", l1,
    311 	    l2 ? l2->l_name : "none", l2,
    312 	    stack, (int)stacksize);
    313 #endif
    314 
    315 	/* copy the PCB and its switchframes from parent */
    316 	memcpy(pcb2, pcb1, sizeof(struct pcb));
    317 
    318 	/* XXXJDM */
    319 	if (stack == NULL) {
    320 		stack = malloc(PAGE_SIZE, M_TEMP, M_NOWAIT);
    321 		stacksize = PAGE_SIZE;
    322 		pcb2->pcb_needfree = true;
    323 	} else
    324 		pcb2->pcb_needfree = false;
    325 
    326 	if (thunk_getcontext(&pcb2->pcb_ucp))
    327 		panic("getcontext failed");
    328 
    329 	/* set up the ucontext for the userland */
    330 	pcb2->pcb_ucp.uc_stack.ss_sp = stack;
    331 	pcb2->pcb_ucp.uc_stack.ss_size = stacksize;
    332 	pcb2->pcb_ucp.uc_link = NULL;
    333 	pcb2->pcb_ucp.uc_flags = _UC_STACK | _UC_CPU;
    334 	thunk_makecontext(&pcb2->pcb_ucp, (void (*)(void))cpu_lwp_trampoline,
    335 	    2, func, arg);
    336 
    337 	/* set up the ucontext for the syscall */
    338 	pcb2->pcb_syscall_ucp.uc_flags = _UC_CPU;
    339 	pcb2->pcb_syscall_ucp.uc_link = NULL;
    340 	pcb2->pcb_syscall_ucp.uc_stack.ss_size = 0;	/* no stack move */
    341 	thunk_makecontext_1(&pcb2->pcb_syscall_ucp, (void (*)(void)) syscall,
    342 	    l2);
    343 }
    344 
    345 void
    346 cpu_initclocks(void)
    347 {
    348 	struct thunk_itimerval itimer;
    349 
    350 	itimer.it_interval.tv_sec = 0;
    351 	itimer.it_interval.tv_usec = 1000000 / HZ;
    352 	itimer.it_value = itimer.it_interval;
    353 	thunk_setitimer(ITIMER_REAL, &itimer, NULL);
    354 }
    355 
    356 void
    357 cpu_startup(void)
    358 {
    359 	msgbuf = thunk_malloc(PAGE_SIZE);
    360 	if (msgbuf == NULL)
    361 		panic("couldn't allocate msgbuf");
    362 	initmsgbuf(msgbuf, PAGE_SIZE);
    363 
    364 	banner();
    365 
    366 	memset(&lwp0pcb, 0, sizeof(lwp0pcb));
    367 	if (thunk_getcontext(&lwp0pcb.pcb_ucp))
    368 		panic("getcontext failed");
    369 	uvm_lwp_setuarea(&lwp0, (vaddr_t)&lwp0pcb);
    370 
    371 	/* init trapframe (going nowhere!), maybe a panic func? */
    372 	memcpy(&lwp0pcb.pcb_userland_ucp, &lwp0pcb.pcb_ucp, sizeof(ucontext_t));
    373 	memcpy(&lwp0pcb.pcb_syscall_ucp,  &lwp0pcb.pcb_ucp, sizeof(ucontext_t));
    374 //	thunk_makecontext_trapframe2go(&lwp0pcb.pcb_userland_ucp, NULL, NULL);
    375 }
    376 
    377 void
    378 cpu_rootconf(void)
    379 {
    380 	device_t rdev;
    381 
    382 	rdev = device_find_by_xname("ld0");
    383 	if (rdev == NULL)
    384 		rdev = device_find_by_xname("md0");
    385 
    386 	aprint_normal("boot device: %s\n",
    387 	    rdev ? device_xname(rdev) : "<unknown>");
    388 	setroot(rdev, 0);
    389 }
    390 
    391 bool
    392 cpu_intr_p(void)
    393 {
    394 	int idepth;
    395 
    396 	kpreempt_disable();
    397 	idepth = curcpu()->ci_idepth;
    398 	kpreempt_enable();
    399 
    400 	return (idepth >= 0);
    401 }
    402