shithub: riscv

--- a/sys/src/9/port/devproc.c

+++ b/sys/src/9/port/devproc.c

@@ -134,7 +134,7 @@

};

 /* Segment type from portdat.h */

-static char *sname[]={ "Text", "Data", "Bss", "Stack", "Shared", "Phys", };

+static char *sname[]={ "Text", "Data", "Bss", "Stack", "Shared", "Phys", "Fixed", };

/*

  * Qids are, in path:

--- a/sys/src/9/port/devsegment.c

+++ b/sys/src/9/port/devsegment.c

@@ -56,6 +56,7 @@

 static	int	cmddone(void*);

 static	void	segmentkproc(void*);

 static	void	docmd(Globalseg *g, int cmd);

+static	Segment* fixedseg(uintptr va, ulong len);

/*

  *  returns with globalseg incref'd

@@ -98,7 +99,7 @@

 	Qid q;

 	Globalseg *g;

-	ulong size;

+	uintptr size;

 	switch(TYPE(c)) {

 	case Qtopdir:

@@ -328,7 +329,11 @@

 		g = c->aux;

 		if(g->s == nil)

 			error("segment not yet allocated");

-		sprint(buf, "va %#lux %#lux\n", g->s->base, g->s->top-g->s->base);

+		if(g->s->type&SG_TYPE == SG_FIXED)

+			sprint(buf, "va %#p %#p fixed %#p\n", g->s->base, g->s->top-g->s->base,

+				g->s->map[0]->pages[0]->pa);

+		else

+			sprint(buf, "va %#p %#p\n", g->s->base, g->s->top-g->s->base);

 		return readstr(voff, a, n, buf);

 	case Qdata:

 		g = c->aux;

@@ -362,7 +367,7 @@

 	Cmdbuf *cb;

 	Globalseg *g;

-	ulong va, len, top;

+	uintptr va, top, len;

 	if(c->qid.type == QTDIR)

 		error(Eperm);

@@ -376,14 +381,19 @@

 				error("already has a virtual address");

 			if(cb->nf < 3)

 				error(Ebadarg);

-			va = strtoul(cb->f[1], 0, 0);

-			len = strtoul(cb->f[2], 0, 0);

+			va = strtoull(cb->f[1], 0, 0);

+			len = strtoull(cb->f[2], 0, 0);

 			top = PGROUND(va + len);

 			va = va&~(BY2PG-1);

-			len = (top - va) / BY2PG;

-			if(len == 0)

+			if(va == 0 || top > USTKTOP || top <= va)

 				error(Ebadarg);

-			g->s = newseg(SG_SHARED, va, len);

+			len = (top - va) / BY2PG;

+			if(cb->nf >= 4 && strcmp(cb->f[3], "fixed") == 0){

+				if(!iseve())

+					error(Eperm);

+				g->s = fixedseg(va, len);

+			} else

+				g->s = newseg(SG_SHARED, va, len);

 		} else

 			error(Ebadctl);

 		break;

@@ -559,6 +569,73 @@

 	pexit("done", 1);

+}

+/*

+ * 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;

+	ulong n, i, j;

+	int color;

+	s = newseg(SG_FIXED, va, len);

+	if(waserror()){

+		putseg(s);

+		nexterror();

+	}

+	lock(&palloc);

+	i = 0;

+	p = palloc.pages;

+	color = getpgcolor(va);

+	for(n = palloc.user; n >= len; n--, p++){

+		if(p->ref != 0 || i != 0 && (p[-1].pa+BY2PG) != p->pa || i == 0 && p->color != color){

+		Retry:

+			i = 0;

+			continue;

+		}

+		if(++i < len)

+			continue;

+		for(j = 0; j < i; j++, p--){

+			for(f = &palloc.head; *f != nil; f = &((*f)->next)){

+				if(*f == p){

+					*f = p->next;

+					goto Freed;

+				}

+			}

+			while(j-- > 0)

+				pagechainhead(++p);

+			goto Retry;

+		Freed:

+			palloc.freecount--;

+		}

+		unlock(&palloc);

+		while(i-- > 0){

+			p++;

+			p->ref = 1;

+			p->va = va;

+			p->modref = 0;

+			p->txtflush = ~0;

+			k = kmap(p);

+			memset((void*)VA(k), 0, BY2PG);

+			kunmap(k);

+			segpage(s, p);

+			va += BY2PG;

+		}

+		poperror();

+		return s;

+	}

+	unlock(&palloc);

+	error(Enomem);

+	return nil;

 Dev segmentdevtab = {

--- a/sys/src/9/port/fault.c

+++ b/sys/src/9/port/fault.c

@@ -267,6 +267,7 @@

 			copypage(old, *pg);

 			putpage(old);

+	case SG_FIXED:			/* Never paged out */

 		mmuphys = PPN((*pg)->pa) | PTEWRITE | PTEVALID;

 		(*pg)->modref = PG_MOD|PG_REF;

 		break;

--- a/sys/src/9/port/portdat.h

+++ b/sys/src/9/port/portdat.h

@@ -341,6 +341,7 @@

 	SG_STACK	= 03,

 	SG_SHARED	= 04,

 	SG_PHYSICAL	= 05,

+	SG_FIXED	= 06,

 	SG_RONLY	= 0040,		/* Segment is read only */

 	SG_CEXEC	= 0100,		/* Detach at exec */

--- a/sys/src/9/port/segment.c

+++ b/sys/src/9/port/segment.c

@@ -156,6 +156,7 @@

 	case SG_TEXT:		/* New segment shares pte set */

 	case SG_SHARED:

 	case SG_PHYSICAL:

+	case SG_FIXED:

 		goto sameseg;

 	case SG_STACK:

@@ -489,8 +490,11 @@

 	if(pages == 0)

 		return;

-	if((s->type&SG_TYPE) == SG_PHYSICAL)

+	switch(s->type&SG_TYPE){

+	case SG_PHYSICAL:

+	case SG_FIXED:

 		return;

+	}

/*

 	 * we have to make sure other processors flush the

--- a/sys/src/9/port/sysproc.c

+++ b/sys/src/9/port/sysproc.c

@@ -751,6 +751,7 @@

 		case SG_DATA:

 		case SG_STACK:

 		case SG_PHYSICAL:

+		case SG_FIXED:

 			error(Ebadarg);

 		default:

 			return (uintptr)ibrk(va_arg(list, uintptr), i);