1992/0120/gnot/bbmalloc.c (diff list | history)

1992/0120/sys/src/9/gnot/bbmalloc.c:1,84 – 1992/0321/sys/src/9/gnot/bbmalloc.c:1,84 (short | long | prev | next)
Move lib.h to ../port. rsc Fri Mar 4 12:44:25 2005
1991/1222		#include "u.h" #include "lib.h"
1992/0321		#include "../port/lib.h"
1991/1222		#include "mem.h" #include "dat.h" #include "fns.h" #include "io.h" /* * Allocate memory for use in kernel bitblts. * The allocated memory must have a flushed instruction * cache, and the data cache must be flushed by bbdflush(). * To avoid the need for frequent cache flushes, the memory * is allocated out of an arena, and the i-cache is only * flushed when it has to be reused. By returning an * address in non-cached space, the need for flushing the * d-cache is avoided. * * This code will have to be interlocked if we ever get * a multiprocessor with a bitmapped display. */ /* a 0->3 bitblt can take 800 longs */ enum { narena=2, /* put interrupt time stuff in separate arena */ nbbarena=4096 /* number of words in an arena */ }; static ulong bbarena[narena][nbbarena]; static ulong *bbcur[narena] = {&bbarena[0][0], &bbarena[1][0]}; static ulong *bblast[narena] = {0, 0}; #define INTLEVEL(v) ((v)&0x700) void * bbmalloc(int nbytes) { int nw, a; int s; ulong *ans; nw = nbytes/sizeof(long); s = splhi(); a = INTLEVEL(s)? 1 : 0; if(bbcur[a] + nw > &bbarena[a][nbbarena]) ans = bbarena[a]; else ans = bbcur[a]; bbcur[a] = ans + nw; splx(s); bblast[a] = ans; return ans; } void bbfree(void *p, int n) { ulong *up; int a, s; s = splhi(); a = INTLEVEL(s)? 1 : 0; if(p == bblast[a]) bbcur[a] = (ulong *)(((char *)bblast[a]) + n); splx(s); }
1992/0120		void
1992/0112		flushvirtpage(void *p) { flushcpucache(); }
1992/0120		void
1991/1222		bbdflush(void *p, int n) { flushcpucache();
1992/0112		} int bbonstack(void) { if(u) return 1; return 0;
1991/1222		}