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cpu.c revision 1.15 
      1 /* $NetBSD: cpu.c,v 1.15 2011/08/13 14:06:54 jmcneill 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 <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: cpu.c,v 1.15 2011/08/13 14:06:54 jmcneill Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/conf.h>
     34 #include <sys/proc.h>
     35 #include <sys/systm.h>
     36 #include <sys/device.h>
     37 #include <sys/reboot.h>
     38 #include <sys/lwp.h>
     39 #include <sys/cpu.h>
     40 #include <sys/mbuf.h>
     41 
     42 #include <dev/cons.h>
     43 
     44 #include <machine/cpu.h>
     45 #include <machine/mainbus.h>
     46 #include <machine/pcb.h>
     47 #include <machine/thunk.h>
     48 
     49 #include <uvm/uvm_extern.h>
     50 #include <uvm/uvm_page.h>
     51 
     52 /* #define CPU_DEBUG */
     53 
     54 static int	cpu_match(device_t, cfdata_t, void *);
     55 static void	cpu_attach(device_t, device_t, void *);
     56 
     57 struct cpu_info cpu_info_primary = {
     58 	.ci_dev = 0,
     59 	.ci_self = &cpu_info_primary,
     60 	.ci_idepth = -1,
     61 	.ci_curlwp = &lwp0,
     62 };
     63 
     64 char cpu_model[48] = "virtual processor";
     65 
     66 typedef struct cpu_softc {
     67 	device_t	sc_dev;
     68 	struct cpu_info	*sc_ci;
     69 } cpu_softc_t;
     70 
     71 static struct pcb lwp0pcb;
     72 
     73 CFATTACH_DECL_NEW(cpu, sizeof(cpu_softc_t), cpu_match, cpu_attach, NULL, NULL);
     74 
     75 static int
     76 cpu_match(device_t parent, cfdata_t match, void *opaque)
     77 {
     78 	struct thunkbus_attach_args *taa = opaque;
     79 
     80 	if (taa->taa_type != THUNKBUS_TYPE_CPU)
     81 		return 0;
     82 
     83 	return 1;
     84 }
     85 
     86 static void
     87 cpu_attach(device_t parent, device_t self, void *opaque)
     88 {
     89 	cpu_softc_t *sc = device_private(self);
     90 
     91 	aprint_naive("\n");
     92 	aprint_normal("\n");
     93 
     94 	sc->sc_dev = self;
     95 	sc->sc_ci = &cpu_info_primary;
     96 }
     97 
     98 void
     99 cpu_configure(void)
    100 {
    101 	if (config_rootfound("mainbus", NULL) == NULL)
    102 		panic("configure: mainbus not configured");
    103 
    104 	spl0();
    105 }
    106 
    107 void
    108 cpu_reboot(int howto, char *bootstr)
    109 {
    110 	extern void usermode_reboot(void);
    111 
    112 	splhigh();
    113 
    114 	if ((howto & RB_POWERDOWN) == RB_POWERDOWN)
    115 		thunk_exit(0);
    116 
    117 	if (howto & RB_HALT) {
    118 		printf("\n");
    119 		printf("The operating system has halted.\n");
    120 		printf("Please press any key to reboot.\n\n");
    121 		cnpollc(1);
    122 		cngetc();
    123 		cnpollc(0);
    124 	}
    125 
    126 	printf("rebooting...\n");
    127 
    128 #if defined(DIAGNOSTIC) || defined(DEBUG)
    129 	thunk_abort();
    130 #endif
    131 
    132 	usermode_reboot();
    133 
    134 	/* NOTREACHED */
    135 }
    136 
    137 void
    138 cpu_need_resched(struct cpu_info *ci, int flags)
    139 {
    140 	ci->ci_want_resched |= flags;
    141 }
    142 
    143 void
    144 cpu_need_proftick(struct lwp *l)
    145 {
    146 }
    147 
    148 lwp_t *
    149 cpu_switchto(lwp_t *oldlwp, lwp_t *newlwp, bool returning)
    150 {
    151 	extern int errno;
    152 	struct pcb *oldpcb = oldlwp ? lwp_getpcb(oldlwp) : NULL;
    153 	struct pcb *newpcb = lwp_getpcb(newlwp);
    154 	struct cpu_info *ci = curcpu();
    155 
    156 #ifdef CPU_DEBUG
    157 	printf("cpu_switchto [%s] -> [%s]\n",
    158 	    oldlwp ? oldlwp->l_name : "none",
    159 	    newlwp ? newlwp->l_name : "none");
    160 	if (oldpcb) {
    161 		printf("    oldpcb uc_link=%p, uc_stack.ss_sp=%p, "
    162 		    "uc_stack.ss_size=%d\n",
    163 		    oldpcb->pcb_ucp.uc_link,
    164 		    oldpcb->pcb_ucp.uc_stack.ss_sp,
    165 		    (int)oldpcb->pcb_ucp.uc_stack.ss_size);
    166 	}
    167 	if (newpcb) {
    168 		printf("    newpcb uc_link=%p, uc_stack.ss_sp=%p, "
    169 		    "uc_stack.ss_size=%d\n",
    170 		    newpcb->pcb_ucp.uc_link,
    171 		    newpcb->pcb_ucp.uc_stack.ss_sp,
    172 		    (int)newpcb->pcb_ucp.uc_stack.ss_size);
    173 	}
    174 #endif /* !CPU_DEBUG */
    175 
    176 	ci->ci_stash = oldlwp;
    177 	curlwp = newlwp;
    178 	if (oldpcb) {
    179 		if (thunk_swapcontext(&oldpcb->pcb_ucp, &newpcb->pcb_ucp))
    180 			panic("swapcontext failed: %d", errno);
    181 	} else {
    182 		if (thunk_setcontext(&newpcb->pcb_ucp))
    183 			panic("setcontext failed: %d", errno);
    184 	}
    185 
    186 #ifdef CPU_DEBUG
    187 	printf("cpu_switchto: returning %p (was %p)\n", ci->ci_stash, oldlwp);
    188 #endif
    189 	return ci->ci_stash;
    190 }
    191 
    192 void
    193 cpu_dumpconf(void)
    194 {
    195 #ifdef CPU_DEBUG
    196 	printf("cpu_dumpconf\n");
    197 #endif
    198 }
    199 
    200 void
    201 cpu_signotify(struct lwp *l)
    202 {
    203 #ifdef CPU_DEBUG
    204 	printf("cpu_signotify\n");
    205 #endif
    206 }
    207 
    208 void
    209 cpu_getmcontext(struct lwp *l, mcontext_t *mcp, unsigned int *flags)
    210 {
    211 #ifdef CPU_DEBUG
    212 	printf("cpu_getmcontext\n");
    213 #endif
    214 }
    215 
    216 int
    217 cpu_setmcontext(struct lwp *l, const mcontext_t *mcp, unsigned int flags)
    218 {
    219 #ifdef CPU_DEBUG
    220 	printf("cpu_setmcontext\n");
    221 #endif
    222 	return 0;
    223 }
    224 
    225 void
    226 cpu_idle(void)
    227 {
    228 	struct cpu_info *ci = curcpu();
    229 
    230 	if (ci->ci_want_resched)
    231 		return;
    232 
    233 #if notyet
    234 	thunk_usleep(10000);
    235 #endif
    236 }
    237 
    238 void
    239 cpu_lwp_free(struct lwp *l, int proc)
    240 {
    241 #ifdef CPU_DEBUG
    242 	printf("cpu_lwp_free\n");
    243 #endif
    244 }
    245 
    246 void
    247 cpu_lwp_free2(struct lwp *l)
    248 {
    249 	struct pcb *pcb = lwp_getpcb(l);
    250 
    251 #ifdef CPU_DEBUG
    252 	printf("cpu_lwp_free2\n");
    253 #endif
    254 
    255 	if (pcb == NULL)
    256 		return;
    257 
    258 	if (pcb->pcb_needfree) {
    259 		free(pcb->pcb_ucp.uc_stack.ss_sp, M_TEMP);
    260 		pcb->pcb_ucp.uc_stack.ss_sp = NULL;
    261 		pcb->pcb_ucp.uc_stack.ss_size = 0;
    262 		pcb->pcb_needfree = false;
    263 	}
    264 }
    265 
    266 static void
    267 cpu_lwp_trampoline(void (*func)(void *), void *arg)
    268 {
    269 	lwp_startup(curcpu()->ci_stash, curlwp);
    270 
    271 	func(arg);
    272 }
    273 
    274 void
    275 cpu_lwp_fork(struct lwp *l1, struct lwp *l2, void *stack, size_t stacksize,
    276     void (*func)(void *), void *arg)
    277 {
    278 	extern int errno;
    279 	struct pcb *pcb = lwp_getpcb(l2);
    280 
    281 #ifdef CPU_DEBUG
    282 	printf("cpu_lwp_fork [%s/%p] -> [%s/%p] stack=%p stacksize=%d\n",
    283 	    l1 ? l1->l_name : "none", l1,
    284 	    l2 ? l2->l_name : "none", l2,
    285 	    stack, (int)stacksize);
    286 #endif
    287 
    288 	/* XXXJDM */
    289 	if (stack == NULL) {
    290 		stack = malloc(PAGE_SIZE, M_TEMP, M_NOWAIT);
    291 		stacksize = PAGE_SIZE;
    292 		pcb->pcb_needfree = true;
    293 	} else
    294 		pcb->pcb_needfree = false;
    295 
    296 	if (thunk_getcontext(&pcb->pcb_ucp))
    297 		panic("getcontext failed: %d", errno);
    298 	pcb->pcb_ucp.uc_stack.ss_sp = stack;
    299 	pcb->pcb_ucp.uc_stack.ss_size = stacksize;
    300 	pcb->pcb_ucp.uc_link = NULL;
    301 	pcb->pcb_ucp.uc_flags = _UC_STACK | _UC_CPU;
    302 	thunk_makecontext(&pcb->pcb_ucp, (void (*)(void))cpu_lwp_trampoline,
    303 	    2, func, arg);
    304 }
    305 
    306 void
    307 cpu_initclocks(void)
    308 {
    309 }
    310 
    311 void
    312 cpu_startup(void)
    313 {
    314 	banner();
    315 
    316 	memset(&lwp0pcb, 0, sizeof(lwp0pcb));
    317 	if (thunk_getcontext(&lwp0pcb.pcb_ucp))
    318 		panic("getcontext failed");
    319 	uvm_lwp_setuarea(&lwp0, (vaddr_t)&lwp0pcb);
    320 }
    321 
    322 void
    323 cpu_rootconf(void)
    324 {
    325 	device_t rdev;
    326 
    327 	rdev = device_find_by_xname("ld0");
    328 	if (rdev == NULL)
    329 		rdev = device_find_by_xname("md0");
    330 
    331 	aprint_normal("boot device: %s\n",
    332 	    rdev ? device_xname(rdev) : "<unknown>");
    333 	setroot(rdev, 0);
    334 }
    335 
    336 bool
    337 cpu_intr_p(void)
    338 {
    339 	int idepth;
    340 
    341 	kpreempt_disable();
    342 	idepth = curcpu()->ci_idepth;
    343 	kpreempt_enable();
    344 
    345 	return (idepth >= 0);
    346 }
    347