Research V6 development

Work on file usr/sys/dmr/ht.c

Synthesized-from: v6

diff --git a/usr/sys/dmr/ht.c b/usr/sys/dmr/ht.c
new file mode 100644 (file)
index 0000000..92440c2
--- /dev/null
+++ b/usr/sys/dmr/ht.c
@@ -0,0 +1,248 @@
+#
+/*
+ */
+
+/*
+ * TJU16 tape driver
+ */
+
+#include "../param.h"
+#include "../buf.h"
+#include "../conf.h"
+#include "../user.h"
+
+struct {
+       int     htcs1;
+       int     htwc;
+       int     htba;
+       int     htfc;
+       int     htcs2;
+       int     htds;
+       int     hter;
+       int     htas;
+       int     htck;
+       int     htdb;
+       int     htmr;
+       int     htdt;
+       int     htsn;
+       int     httc;
+       int     htbae;  /* 11/70 bus extension */
+};
+
+struct devtab  httab;
+struct buf     rhtbuf;
+
+#define        NUNIT   8
+
+char   h_openf[NUNIT];
+char   *h_blkno[NUNIT];
+char   *h_nxrec[NUNIT];
+
+#define        HTADDR  0172440
+
+#define        GO      01
+#define        NOP     0
+#define        WEOF    026
+#define        SFORW   030
+#define        SREV    032
+#define        ERASE   024
+#define        REW     06
+#define        CLR     010
+#define        P800    01300           /* 800 + pdp11 mode */
+#define        P1600   02300           /* 1600 + pdp11 mode */
+#define        IENABLE 0100
+#define        CRDY    0200
+#define        EOF     04
+#define        DRY     0200
+#define        MOL     010000
+#define        PIP     020000
+#define        ERR     040000
+
+#define        SSEEK   1
+#define        SIO     2
+
+htopen(dev, flag)
+{
+       register unit;
+
+       unit = dev.d_minor&077;
+       if (unit >= NUNIT || h_openf[unit])
+               u.u_error = ENXIO;
+       else {
+               h_openf[unit]++;
+               h_blkno[unit] = 0;
+               h_nxrec[unit] = 65535;
+               hcommand(dev, NOP);
+       }
+}
+
+htclose(dev, flag)
+{
+       register int unit;
+
+       unit = dev.d_minor&077;
+       h_openf[unit] = 0;
+       if (flag) {
+               hcommand(dev, WEOF);
+               hcommand(dev, WEOF);
+       }
+       hcommand(dev, REW);
+}
+
+hcommand(dev, com)
+{
+       register unit;
+       extern lbolt;
+
+       unit = dev.d_minor;
+       while (httab.d_active || (HTADDR->htcs1 & CRDY)==0)
+               sleep(&lbolt, 1);
+       HTADDR->htcs2 = (unit>>3)&07;
+       while((HTADDR->htds&DRY) == 0)
+               sleep(&lbolt, 1);
+       if(unit >= 64)
+               HTADDR->httc = P800 | (unit&07); else
+               HTADDR->httc = P1600 | (unit&07);
+       while((HTADDR->htds&(MOL|PIP)) != MOL)
+               sleep(&lbolt, 1);
+       HTADDR->htcs1 = com | GO;
+}
+
+htstrategy(abp)
+struct buf *abp;
+{
+       register struct buf *bp;
+       register char **p;
+
+       bp = abp;
+       p = &h_nxrec[bp->b_dev.d_minor&077];
+       if (*p <= bp->b_blkno) {
+               if (*p < bp->b_blkno) {
+                       bp->b_flags =| B_ERROR;
+                       iodone(bp);
+                       return;
+               }
+               if (bp->b_flags&B_READ) {
+                       clrbuf(bp);
+                       iodone(bp);
+                       return;
+               }
+       }
+       if ((bp->b_flags&B_READ)==0)
+               *p = bp->b_blkno + 1;
+       bp->av_forw = 0;
+       spl5();
+       if (httab.d_actf==0)
+               httab.d_actf = bp;
+       else
+               httab.d_actl->av_forw = bp;
+       httab.d_actl = bp;
+       if (httab.d_active==0)
+               htstart();
+       spl0();
+}
+
+htstart()
+{
+       register struct buf *bp;
+       register int unit;
+       register char *blkno;
+
+    loop:
+       if ((bp = httab.d_actf) == 0)
+               return;
+       unit = bp->b_dev.d_minor;
+       HTADDR->htcs2 = (unit>>3)&07;
+       if(unit >= 64)
+               HTADDR->httc = P800 | (unit&07); else
+               HTADDR->httc = P1600 | (unit&07);
+       unit =& 077;
+       blkno = h_blkno[unit];
+       if (h_openf[unit] < 0 || (HTADDR->htcs1 & CRDY)==0) {
+               bp->b_flags =| B_ERROR;
+               httab.d_actf = bp->av_forw;
+               iodone(bp);
+               goto loop;
+       }
+       if (blkno != bp->b_blkno) {
+               httab.d_active = SSEEK;
+               if (blkno < bp->b_blkno) {
+                       HTADDR->htfc = blkno - bp->b_blkno;
+                       HTADDR->htcs1 = SFORW|IENABLE|GO;
+               } else {
+                       if (bp->b_blkno == 0)
+                               HTADDR->htcs1 = REW|IENABLE|GO;
+                       else {
+                               HTADDR->htfc = bp->b_blkno - blkno;
+                               HTADDR->htcs1 = SREV|IENABLE|GO;
+                       }
+               }
+               return;
+       }
+       httab.d_active = SIO;
+       rhstart(bp, &HTADDR->htfc, bp->b_wcount<<1, &HTADDR->htbae);
+}
+
+htintr()
+{
+       register struct buf *bp;
+       register int unit;
+
+       if ((bp = httab.d_actf)==0)
+               return;
+       unit = bp->b_dev.d_minor&077;
+       if (HTADDR->htcs1 & ERR) {
+/*
+               deverror(bp, HTADDR->hter, 0);
+ */
+               if(HTADDR->htds&EOF) {
+                       if(bp != &rhtbuf && h_openf[unit])
+                               h_openf[unit] = -1;
+               }
+               HTADDR->htcs1 = ERR|CLR|GO;
+               if ((HTADDR->htds&DRY)!=0 && httab.d_active==SIO) {
+                       if (++httab.d_errcnt < 10) {
+                               h_blkno[unit]++;
+                               httab.d_active = 0;
+                               htstart();
+                               return;
+                       }
+               }
+               bp->b_flags =| B_ERROR;
+               httab.d_active = SIO;
+       }
+       if (httab.d_active == SIO) {
+               httab.d_errcnt = 0;
+               h_blkno[unit]++;
+               httab.d_actf = bp->av_forw;
+               httab.d_active = 0;
+               iodone(bp);
+               bp->b_resid = HTADDR->htfc;
+       } else
+               h_blkno[unit] = bp->b_blkno;
+       htstart();
+}
+
+htread(dev)
+{
+       htphys(dev);
+       physio(htstrategy, &rhtbuf, dev, B_READ);
+       u.u_count = -rhtbuf.b_resid;
+}
+
+htwrite(dev)
+{
+       htphys(dev);
+       physio(htstrategy, &rhtbuf, dev, B_WRITE);
+       u.u_count = 0;
+}
+
+htphys(dev)
+{
+       register unit, a;
+
+       unit = dev.d_minor;
+       a = lshift(u.u_offset, -9);
+       h_blkno[unit] = a;
+       h_nxrec[unit] = ++a;
+}