#include	"u.h"#include	"../port/lib.h"#include	"mem.h"#include	"dat.h"#include	"fns.h"#include	"../port/error.h" enum{	Qtopdir,	Qsegdir,	Qctl,	Qdata,}; #define TYPE(x) 	(int)( (c)->qid.path & 0x7 )#define SEG(x)	 	( ((c)->qid.path >> 3) & 0x3f )#define PATH(s, t) 	( ((s)<<3) | (t) ) typedef struct Globalseg Globalseg;struct Globalseg{	Ref; 	char	*name;	char	*uid;	vlong	length;	long	perm; 	Segio;}; static Globalseg *globalseg[100];static Lock globalseglock;  	Segment* (*_globalsegattach)(char*);static	Segment* globalsegattach(char *name); static	Segment* fixedseg(uintptr va, ulong len); /* *  returns with globalseg incref'd */static Globalseg*getgseg(Chan *c){	int x;	Globalseg *g; 	x = SEG(c);	lock(&globalseglock);	if(x >= nelem(globalseg))		panic("getgseg");	g = globalseg[x];	if(g != nil)		incref(g);	unlock(&globalseglock);	if(g == nil)		error("global segment disappeared");	return g;} static voidputgseg(Globalseg *g){	if(g == nil || decref(g))		return;	if(g->s != nil)		putseg(g->s);	segio(g, nil, nil, 0, 0, 0);	free(g->name);	free(g->uid);	free(g);} static intsegmentgen(Chan *c, char*, Dirtab*, int, int s, Dir *dp){	Qid q;	Globalseg *g;	uintptr size; 	switch(TYPE(c)) {	case Qtopdir:		if(s == DEVDOTDOT){			q.vers = 0;			q.path = PATH(0, Qtopdir);			q.type = QTDIR;			devdir(c, q, "#g", 0, eve, DMDIR|0777, dp);			break;		} 		if(s >= nelem(globalseg))			return -1; 		lock(&globalseglock);		g = globalseg[s];		if(g == nil){			unlock(&globalseglock);			return 0;		}		q.vers = 0;		q.path = PATH(s, Qsegdir);		q.type = QTDIR;		kstrcpy(up->genbuf, g->name, sizeof up->genbuf);		devdir(c, q, up->genbuf, 0, g->uid, DMDIR|0777, dp);		unlock(&globalseglock);		break;	case Qsegdir:		if(s == DEVDOTDOT){			q.vers = 0;			q.path = PATH(0, Qtopdir);			q.type = QTDIR;			devdir(c, q, "#g", 0, eve, DMDIR|0777, dp);			break;		}		/* fall through */	case Qctl:	case Qdata:		switch(s){		case 0:			g = getgseg(c);			q.vers = 0;			q.path = PATH(SEG(c), Qctl);			q.type = QTFILE;			devdir(c, q, "ctl", 0, g->uid, g->perm, dp);			putgseg(g);			break;		case 1:			g = getgseg(c);			q.vers = 0;			q.path = PATH(SEG(c), Qdata);			q.type = QTFILE;			if(g->s != nil)				size = g->s->top - g->s->base;			else				size = 0;			devdir(c, q, "data", size, g->uid, g->perm, dp);			putgseg(g);			break;		default:			return -1;		}		break;	}	return 1;} static voidsegmentinit(void){	_globalsegattach = globalsegattach;} static Chan*segmentattach(char *spec){	return devattach('g', spec);} static Walkqid*segmentwalk(Chan *c, Chan *nc, char **name, int nname){	return devwalk(c, nc, name, nname, 0, 0, segmentgen);} static intsegmentstat(Chan *c, uchar *db, int n){	return devstat(c, db, n, 0, 0, segmentgen);} static Chan*segmentopen(Chan *c, int omode){	Globalseg *g; 	switch(TYPE(c)){	case Qtopdir:	case Qsegdir:		if(omode != 0)			error(Eisdir);		break;	case Qctl:	case Qdata:		g = getgseg(c);		if(waserror()){			putgseg(g);			nexterror();		}		devpermcheck(g->uid, g->perm, omode);		if(TYPE(c) == Qdata && g->s == nil)			error("segment not yet allocated");		c->aux = g;		poperror();		break;	default:		panic("segmentopen");	}	c->mode = openmode(omode);	c->offset = 0;	c->flag |= COPEN;	return c;} static voidsegmentclose(Chan *c){	switch(TYPE(c)){	case Qctl:	case Qdata:		if(c->flag & COPEN){			putgseg(c->aux);			c->aux = nil;		}	}} static Chan*segmentcreate(Chan *c, char *name, int omode, ulong perm){	int x, xfree;	Globalseg *g; 	if(TYPE(c) != Qtopdir)		error(Eperm); 	if(strlen(name) >= sizeof(up->genbuf))		error(Etoolong); 	if(findphysseg(name) != nil)		error("name collision with physical segment"); 	if((perm & DMDIR) == 0)		error(Ebadarg); 	if(waserror()){		unlock(&globalseglock);		nexterror();	}	lock(&globalseglock);	xfree = -1;	for(x = 0; x < nelem(globalseg); x++){		g = globalseg[x];		if(g == nil){			if(xfree < 0)				xfree = x;		} else if(strcmp(g->name, name) == 0)			error(Eexist);	}	if(xfree < 0)		error("too many global segments");	g = smalloc(sizeof(Globalseg));	g->ref = 1;	kstrdup(&g->name, name);	kstrdup(&g->uid, up->user);	g->perm = 0660; 	globalseg[xfree] = g;	unlock(&globalseglock);	poperror(); 	c->qid.path = PATH(x, Qsegdir);	c->qid.type = QTDIR;	c->qid.vers = 0;	c->mode = openmode(omode);	return c;} static longsegmentread(Chan *c, void *a, long n, vlong voff){	Globalseg *g;	char buf[128]; 	if(c->qid.type == QTDIR)		return devdirread(c, a, n, (Dirtab *)0, 0L, segmentgen); 	g = c->aux;	switch(TYPE(c)){	case Qctl:		if(g->s == nil)			error("segment not yet allocated");		if((g->s->type&SG_TYPE) == SG_FIXED)			snprint(buf, sizeof(buf), "va %#p %#p fixed %#p\n", g->s->base, g->s->top-g->s->base,				g->s->map[0]->pages[0]->pa);		else			snprint(buf, sizeof(buf), "va %#p %#p\n", g->s->base, g->s->top-g->s->base);		return readstr(voff, a, n, buf);	case Qdata:		return segio(g, g->s, a, n, voff, 1);	default:		panic("segmentread");	}	return 0;	/* not reached */} static longsegmentwrite(Chan *c, void *a, long n, vlong voff){	Cmdbuf *cb;	Globalseg *g;	uintptr va, top, len; 	if(c->qid.type == QTDIR)		error(Eperm); 	g = c->aux;	switch(TYPE(c)){	case Qctl:		cb = parsecmd(a, n);		if(waserror()){			free(cb);			nexterror();		}		if(strcmp(cb->f[0], "va") == 0){			if(g->s != nil)				error("already has a virtual address");			if(cb->nf < 3)				error(Ebadarg);			va = strtoull(cb->f[1], 0, 0);			len = strtoull(cb->f[2], 0, 0);			top = PGROUND(va + len);			va = va&~(BY2PG-1);			if(va == 0 || top > USTKTOP || top <= va)				error(Ebadarg);			len = top - va;			if(len > SEGMAXSIZE)				error(Enovmem);			if(cb->nf >= 4 && strcmp(cb->f[3], "fixed") == 0){				if(!iseve())					error(Eperm);				g->s = fixedseg(va, len/BY2PG);			} else				g->s = newseg(SG_SHARED, va, len/BY2PG);		} else			error(Ebadctl);		free(cb);		poperror();		break;	case Qdata:		return segio(g, g->s, a, n, voff, 0);	default:		panic("segmentwrite");	}	return 0;	/* not reached */} static intsegmentwstat(Chan *c, uchar *dp, int n){	Globalseg *g;	Dir *d; 	if(c->qid.type == QTDIR)		error(Eperm); 	d = nil;	g = getgseg(c);	if(waserror()){		free(d);		putgseg(g);		nexterror();	}	if(strcmp(g->uid, up->user) && !iseve())		error(Eperm);	d = smalloc(sizeof(Dir)+n);	n = convM2D(dp, n, &d[0], (char*)&d[1]);	if(n == 0)		error(Eshortstat);	if(!emptystr(d->uid))		kstrdup(&g->uid, d->uid);	if(d->mode != ~0UL)		g->perm = d->mode&0777;	free(d);	putgseg(g);	poperror(); 	return n;} static voidsegmentremove(Chan *c){	Globalseg *g;	int x; 	if(TYPE(c) != Qsegdir)		error(Eperm);	lock(&globalseglock);	x = SEG(c);	g = globalseg[x];	globalseg[x] = nil;	unlock(&globalseglock);	if(g != nil)		putgseg(g);} /* *  called by segattach() */static Segment*globalsegattach(char *name){	int x;	Globalseg *g;	Segment *s; 	if(waserror()){		unlock(&globalseglock);		nexterror();	}	lock(&globalseglock);	for(x = 0; x < nelem(globalseg); x++){		g = globalseg[x];		if(g != nil && strcmp(g->name, name) == 0)			goto Found;	}	unlock(&globalseglock);	poperror();	return nil;Found:	devpermcheck(g->uid, g->perm, ORDWR);	s = g->s;	if(s == nil)		error("global segment not assigned a virtual address");	incref(s);	unlock(&globalseglock);	poperror();	return s;} /* * allocate a fixed segment with sequential run of of adjacent * user memory pages. */static Segment*fixedseg(uintptr va, ulong len){	KMap *k;	Segment *s;	Page **f, *p, *l, *h;	ulong n, i;	int color; 	s = newseg(SG_FIXED, va, len);	if(waserror()){		putseg(s);		nexterror();	}	lock(&palloc);	i = 0;	l = palloc.pages;	color = getpgcolor(va);	for(n = palloc.user; n >= len; n--, l++){		if(l->ref != 0 || i != 0 && (l[-1].pa+BY2PG) != l->pa || i == 0 && l->color != color){		Retry:			i = 0;			continue;		}		if(++i < len)			continue; 		i = 0;		h = nil;		f = &palloc.head;		while((p = *f) != nil){			if(p > &l[-len] && p <= l){				*f = p->next;				p->next = h;				h = p;				if(++i < len)					continue;				break;			}			f = &p->next;		}		palloc.freecount -= i; 		if(i != len){			while((p = h) != nil){				h = h->next;				pagechainhead(p);			}			goto Retry;		}		unlock(&palloc); 		p = &l[-len];		do {			p++;			p->ref = 1;			p->va = va;			p->modref = 0;			p->txtflush = ~0;						k = kmap(p);			memset((void*)VA(k), 0, BY2PG);			kunmap(k);			

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