#include <u.h>#include <libc.h> /* Routines for letting gbitblt run at user level */ enum {	nbbarena = 20000,	linewords = (64/sizeof(ulong)),}; static ulong bbarena[nbbarena];static ulong *bbcur = bbarena;static ulong *bblast = bbarena; void *bbmalloc(int nbytes){	int nw;	ulong *ans; 	nw = nbytes/sizeof(long);	if(bbcur + nw > &bbarena[nbbarena])		ans = bblast = bbarena;	else		ans = bbcur;	bbcur = ans + nw;	if(ans == bbarena)		segflush(ans, nbbarena*sizeof(ulong));	bblast = ans;	return ans;} voidbbfree(void *a, int n){	USED(a);	bbcur = (ulong *)(((char *)bblast) + n + linewords*sizeof(long));} intbbonstack(void){#ifdef Tmips	return 0;#else	return 1;#endif} #ifdef T68020voidflushvirtpage(void *p){	segflush(p, 200);	/* 200 > bytes in biggest non-converting bitblt */} voidbbdflush(void *p, int n){	segflush(p, n);}#endif #ifdef Tmipsvoidwbflush(void){	/* mips has write-through data cache */	/* assume this call is enough to trickle data cache out */} voidicflush(void *p, int n){	segflush(p, n);}#endif