/* * power management */ #include	"u.h"#include	"../port/lib.h"#include	"mem.h"#include	"dat.h"#include	"fns.h"#include	"../port/error.h" typedef struct Power Power;typedef struct Puser Puser; enum{	Qdir,	Qctl,	Qdata}; staticDirtab powertab[]={	".",			{Qdir, 0, QTDIR},	0,	0500,	"powerctl",		{Qctl, 0},		0,	0600,	"powerdata",		{Qdata, 0},	0,	0666,}; struct Puser {	Ref;	ulong	alarm;	/* real time clock alarm time, if non-zero */	QLock	rl;		/* mutual exclusion to protect r */	Rendez	r;		/* wait for event of interest */	int	state;	/* shutdown state of this process */	Puser*	next;}; enum{	Pwridle,	Pwroff,	Pwrack}; static struct {	QLock;	Puser	*list;	Lock	l;	/* protect shutdown, nwaiting */	int	shutdown;	/* non-zero if currently shutting down */	int	nwaiting;		/* waiting for this many processes */	Rendez	ackr;	/* wait here for all acks */} pwrusers;  static Chan*powerattach(char* spec){	return devattach(L'↓', spec);} static intpowerwalk(Chan* c, char* name){	return devwalk(c, name, powertab, nelem(powertab), devgen);} static voidpowerstat(Chan* c, char* db){	devstat(c, db, powertab, nelem(powertab), devgen);} static Chan*poweropen(Chan* c, int omode){	Puser *p; 	if(c->qid.type & QTDIR)		return devopen(c, omode, powertab, nelem(powertab), devgen);	switch(c->qid.path){	case Qdata:		p = mallocz(sizeof(Puser), 1);		if(p == nil)			error(Enovmem);		p->state = Pwridle;		p->ref = 1;		if(waserror()){			free(p);			nexterror();		}		c = devopen(c, omode, powertab, nelem(powertab), devgen);		c->aux = p;		qlock(&pwrusers);		p->next = pwrusers.list;		pwrusers.list = p;	/* note: must place on front of list for correct shutdown ordering */		qunlock(&pwrusers);		poperror();		break;	case Qctl:		c = devopen(c, omode, powertab, nelem(powertab), devgen);		break;	}	return c;} static Chan *powerclone(Chan *c, Chan *nc){	Puser *p; 	nc = devclone(c, nc);	if((p = nc->aux) != nil)		incref(p);	return nc;} static voidpowerclose(Chan* c){	Puser *p, **l; 	if(c->qid.type & QTDIR || (c->flag & COPEN) == 0)		return;	p = c->aux;	if(p != nil && decref(p) == 0){		/* TO DO: cancel alarm */		qlock(&pwrusers);		for(l = &pwrusers.list; *l != nil; l = &(*l)->next)			if(*l == p){				*l = p->next;				break;			}		qunlock(&pwrusers);		free(p);	}} static intisshutdown(void *a){	return ((Puser*)a)->state == Pwroff;} static longpowerread(Chan* c, void* a, long n, vlong offset){	Puser *p;	char *msg; 	switch(c->qid.path & ~CHDIR){	case Qdir:		return devdirread(c, a, n, powertab, nelem(powertab), devgen);	case Qdata:		p = c->aux;		for(;;){			if(!canqlock(&p->rl))				error(Einuse);	/* only one reader at a time */			if(waserror()){				qunlock(&p->rl);				nexterror();			}			sleep(&p->r, isshutdown, p);			poperror();			qunlock(&p->rl);			msg = nil;			lock(p);			if(p->state == Pwroff){				msg = "power off";				p->state = Pwrack;			}			unlock(p);			if(msg != nil)				return readstr(offset, a, n, msg);		}		break;	case Qctl:	default:		n=0;		break;	}	return n;} static intalldown(void*){	return pwrusers.nwaiting == 0;} static longpowerwrite(Chan* c, void *a, long n, vlong){	Cmdbuf *cmd;	Puser *p; 	if(c->qid.type & QTDIR)		error(Ebadusefd);	cmd = parsecmd(a, n);	if(waserror()){		free(cmd);		nexterror();	}	switch(c->qid.path & ~CHDIR){	case Qdata:		p = c->aux;		if(cmd->nf < 2)			error(Ebadarg);		if(strcmp(cmd->f[0], "ack") == 0){			if(strcmp(cmd->f[1], "power") == 0){				lock(p);				if(p->state == Pwrack){					lock(&pwrusers.l);					if(pwrusers.shutdown && pwrusers.nwaiting > 0)						pwrusers.nwaiting--;					unlock(&pwrusers.l);					wakeup(&pwrusers.ackr);					p->state = Pwridle;				}				unlock(p);			}else				error(Ebadarg);		}else if(strcmp(cmd->f[0], "alarm") == 0){			/* set alarm */		}else			error(Ebadarg);		break;	case Qctl:		if(cmd->nf < 1)			error(Ebadarg);		if(strcmp(cmd->f[0], "suspend") == 0){			/* start the suspend action */			qlock(&pwrusers);			//powersuspend(0);	/* calls poweringdown, then archsuspend() */			qunlock(&pwrusers);		}else if(strcmp(cmd->f[0], "shutdown") == 0){			/* go to it */			qlock(&pwrusers);			if(waserror()){				lock(&pwrusers.l);				pwrusers.shutdown = 0;	/* hard luck for those already notified */				unlock(&pwrusers.l);				qunlock(&pwrusers);				nexterror();			}			lock(&pwrusers.l);			pwrusers.shutdown = 1;			pwrusers.nwaiting = 0;			unlock(&pwrusers.l);			for(p = pwrusers.list; p != nil; p = p->next){				lock(p);				if(p->state == Pwridle){					p->state = Pwroff;					lock(&pwrusers.l);					pwrusers.nwaiting++;					unlock(&pwrusers.l);				}				unlock(p);				wakeup(&p->r);				/* putting the tsleep here does each in turn; move out of loop to multicast */				tsleep(&pwrusers.ackr, alldown, nil, 1000);			}			poperror();			qunlock(&pwrusers);			//powersuspend(1);		}else			error(Ebadarg);		free(cmd);		break;	default:		error(Ebadusefd);	}	poperror();	return n;} /* * device-level power management: suspend/resume/shutdown */ struct Power {	void	(*f)(int);	Power*	prev;	Power*	next;}; static struct {	Lock;	Power	list;} power; voidpowerenablereset(void){	power.list.next = power.list.prev = &power.list;	power.list.f = (void*)-1;	/* something not nil */} voidpowerenable(void (*f)(int)){	Power *p, *l; 	p = malloc(sizeof(*p));	p->f = f;	p->prev = nil;	p->next = nil;	ilock(&power);	for(l = power.list.next; l != &power.list; l = l->next)		if(l->f == f){			iunlock(&power);			free(p);			return;		}	l = &power.list;	p->prev = l->prev;	l->prev = p;	p->next = l;	p->prev->next = p;	iunlock(&power);} voidpowerdisable(void (*f)(int)){	Power *l; 	ilock(&power);	for(l = power.list.next; l != &power.list; l = l->next)		if(l->f == f){			l->prev->next = l->next;			l->next->prev = l->prev;			free(l);			break;		}	iunlock(&power);} /* * interrupts are assumed off so there's no need to lock */voidpoweringup(void){	Power *l; 	for(l = power.list.next; l != &power.list; l = l->next)		(*l->f)(1);} voidpoweringdown(void){	Power *l; 	for(l = power.list.prev; l != &power.list; l = l->prev)		(*l->f)(0);} Dev powerdevtab = {	L'↓',	"power", 	devreset,	devinit,	powerattach,	devdetach,	powerclone,	powerwalk,	powerstat,	poweropen,	devcreate,	powerclose,	powerread,	devbread,	powerwrite,	devbwrite,	devremove,	devwstat,};