From 84fc9dc11138b716afeaaad735e403df5c0cafcc Mon Sep 17 00:00:00 2001
From: David du Colombier <0intro@gmail.com>
Date: Thu, 16 Jan 1992 00:00:00 +0000
Subject: [PATCH] Plan 9 from Bell Labs 1992-01-16

---
 pc/mmu.c      |  2 +-
 ss/bbmalloc.c | 27 +++++----------------------
 2 files changed, 6 insertions(+), 23 deletions(-)

diff --git a/pc/mmu.c b/pc/mmu.c
index a1b2fc047a7945dce050bcbc4b4503bb877073f6..8ae0718f1804b8648efd9d7c9f7f181bb75590dc 100644
--- a/pc/mmu.c
+++ b/pc/mmu.c
@@ -53,7 +53,7 @@ Tss tss;
 #define	D16SEGM(p) 	{ 0xFFFF, (0x0<<16)|SEGP|SEGPL(p)|SEGDATA|SEGW }
 #define	E16SEGM(p) 	{ 0xFFFF, (0x0<<16)|SEGP|SEGPL(p)|SEGEXEC|SEGR }
 #define	TSSSEGM(b,p)	{ ((b)<<16)|sizeof(Tss),\
-			  ((b)&0xFF000000)|(((b)<<16)&0xFF)|SEGTSS|SEGPL(p)|SEGP }
+			  ((b)&0xFF000000)|(((b)>>16)&0xFF)|SEGTSS|SEGPL(p)|SEGP }
 
 /*
  *  global descriptor table describing all segments
diff --git a/ss/bbmalloc.c b/ss/bbmalloc.c
index c9eed4fe01c8a16304020c82e9e7112e57d5f632..e99f9ae822c1ee42ce5cf919ea13250f9c746dea 100644
--- a/ss/bbmalloc.c
+++ b/ss/bbmalloc.c
@@ -7,21 +7,6 @@
 
 /*
  * 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.
- *
- * Currently, the only kernel users of bitblt are devbit,
- * print, and the cursor stuff in devbit.  The cursor
- * can get drawn at clock interrupt time, so it might need
- * to bbmalloc while another bitblt is going on.
- *
- * This code will have to be interlocked if we ever get
- * a multiprocessor with a bitmapped display.
  */
 
 /* a 0->3 bitblt can take 900 words */
@@ -48,10 +33,6 @@ bbmalloc(int nbytes)
 		ans = bbcur;
 	bbcur = ans + nw;
 	splx(s);
-/*
-	if(ans == bbarena)
-		icflush(ans, sizeof(bbarena));
-*/
 	bblast = ans;
 	ans = (void *)ans;
 	return ans;
@@ -66,8 +47,10 @@ bbfree(void *p, int n)
 		bbcur = (ulong *)(((char *)bblast) + n);
 }
 
-void *
-bbdflush(void *p, int n)
+int
+bbonstack(void)
 {
-	return p;
+	if(u)
+		return 1;
+	return 0;
 }