TempleOSCD_150720.ISO

Kernel/Dsk/DskBlkDev.CPP

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+Bool BlkDevLock(CBlkDev *bd)
+{//Make this task have exclusive access to BlkDev.
+  BlkDevChk(bd);
+  while (bd->lock_fwding)
+    bd=bd->lock_fwding; //If two blkdevs on same controller, use just one lock
+  if (!Bt(&bd->locked_flags,BDlf_LOCKED) || bd->owning_task!=Fs) {
+    while (LBts(&bd->locked_flags,BDlf_LOCKED))
+      Yield;
+    bd->owning_task=Fs;
+    return TRUE;
+  } else
+    return FALSE;
+}
+
+Bool BlkDevUnlock(CBlkDev *bd,Bool rst=FALSE)
+{//Release exclusive lock on access to BlkDev.
+  BlkDevChk(bd);
+  while (bd->lock_fwding)
+    bd=bd->lock_fwding; //If two blkdevs on same controller, use just one lock
+  if (Bt(&bd->locked_flags,BDlf_LOCKED) && bd->owning_task==Fs) {
+    if (rst)
+      bd->flags&=~(BDF_INITIALIZED|BDF_INIT_IN_PROGRESS);
+    bd->owning_task=NULL;
+    LBtr(&bd->locked_flags,BDlf_LOCKED);
+    Yield; //Prevent deadlock
+    return TRUE;
+  } else
+    return FALSE;
+}
+
+Bool BlkDevInit(CBlkDev *bd)
+{
+  CDrv *dv=Let2Drv(bd->first_drv_let);
+  Bool old_preempt=Preempt,result=FALSE;
+
+  if (!LBts(&bd->flags,BDf_INITIALIZED)) {
+    bd->flags|=BDF_INIT_IN_PROGRESS;
+    switch(bd->type) {
+      case BDT_RAM:
+	if (!bd->RAM_dsk) {
+	  bd->RAM_dsk=AMAlloc((bd->max_blk+1)<<BLK_SIZE_BITS);
+	  bd->max_blk=MSize(bd->RAM_dsk)>>BLK_SIZE_BITS-1;
+	}
+	dv->type=DVT_REDSEA;
+	dv->size=bd->max_blk+1;
+	if (RedSeaDrvValidate(bd->first_drv_let))
+	  RedSeaDrvInit(dv);
+	else
+	  RedSeaFmt(bd->first_drv_let);
+	result=TRUE;
+	break;
+      case BDT_ATA:
+	bd->max_reads=128;
+	bd->max_writes=1;
+	result=ATAInit(bd);
+	break;
+      case BDT_ATAPI:
+//0xFFFF*4 is too big for my taste
+	bd->max_reads=0x800*4;
+//max of maybe a quarter of disk cache
+	if (bd->max_reads>dsk.cache_size/BLK_SIZE/4)
+	  bd->max_reads=dsk.cache_size/BLK_SIZE/4 & ~3;
+	if (bd->max_reads<128)
+	  bd->max_reads=128;
+	bd->max_writes=0xFFFF*4;
+	if (result=ATAInit(bd))
+	  dv->size=bd->max_blk+1;
+	break;
+    }
+    if (result && bd->flags & BDF_READ_CACHE)
+      DskCacheInvalidate(dv);
+    bd->flags&=~BDF_INIT_IN_PROGRESS;
+  } else
+    result=TRUE;
+  Preempt(old_preempt);
+  return result;
+}
+
+U0 BlkDevsRelease()
+{//When task dies, release all owned BlkDevs.
+  I64 i;
+  CBlkDev *bd;
+  for (i=0;i<NUM_BLKDEVS;i++) {
+    bd=&dsk.blkdevs[i];
+    if (bd->owning_task==Fs && bd->bd_signature==BD_SIGNATURE_VAL)
+      BlkDevUnlock(bd,TRUE);
+  }
+}
+
+CBlkDev *BlkDevNextFree(U8 first_drv_let,I64 type)
+{//Locate free slot for new BlkDev, like during $LK,"Mount",A="MN:Mount"$().
+  I64 i=0;
+  CBlkDev *result;
+  do {
+    result=&dsk.blkdevs[i];
+    if (result->bd_signature!=BD_SIGNATURE_VAL) {
+      MemSet(result,0,sizeof(CBlkDev));
+      result->first_drv_let=first_drv_let;
+      result->type=type;
+      if (type==BDT_ATAPI)
+	result->flags=BDF_REMOVABLE;
+      else
+	result->flags=0;
+      if (type!=BDT_RAM)
+	result->flags|=BDF_READ_CACHE;
+
+      if (type==BDT_ATAPI) {
+	result->blk_size=CD_BLK_SIZE;
+	result->flags|=BDF_READ_ONLY;
+      } else
+	result->blk_size=BLK_SIZE;
+
+      result->max_blk=0xEFFFFFFF;
+      return result;
+    }
+  } while (++i<NUM_BLKDEVS);
+  throw('BlkDev');
+  return NULL; //never gets here
+}
+
+U0 BlkDevChk(CBlkDev *bd)
+{//Check for valid BlkDev. Throw exception.
+  if (!bd || bd->bd_signature!=BD_SIGNATURE_VAL ||
+	!(BDT_NULL<bd->type<BDT_NUM_TYPES))
+    throw('BlkDev');
+}
+
+CBlkDev *Let2BlkDev(U8 drv_let=0)
+{//Drv letter to BlkDev ptr.
+  CDrv *dv=Let2Drv(drv_let);
+  CBlkDev *bd=dv->bd;
+  BlkDevChk(bd);
+  return bd;
+}