if (*pre < 3) (*pre)++; /* else fail later */
                        div = pre_div[*pre]*-*pcr;
                        DPRINTK("max div %d\n",div);
-                       *res = (TS_CLOCK+div-1)/div-1;
+                       *res = DIV_ROUND_UP(TS_CLOCK, div)-1;
                }
                if (*res < 0) *res = 0;
                if (*res > MID_SEG_MAX_RATE) *res = MID_SEG_MAX_RATE;
 
                // take care of rounding
                switch (r) {
                        case round_down:
-                               pre = (br+(c<<div)-1)/(c<<div);
+                               pre = DIV_ROUND_UP(br, c<<div);
                                // but p must be non-zero
                                if (!pre)
                                        pre = 1;
                        // take care of rounding
                        switch (r) {
                                case round_down:
-                                       pre = (br+(c<<div)-1)/(c<<div);
+                                       pre = DIV_ROUND_UP(br, c<<div);
                                        break;
                                case round_nearest:
                                        pre = (br+(c<<div)/2)/(c<<div);
                if (bits)
                        *bits = (div<<CLOCK_SELECT_SHIFT) | (pre-1);
                if (actual) {
-                       *actual = (br + (pre<<div) - 1) / (pre<<div);
+                       *actual = DIV_ROUND_UP(br, pre<<div);
                        PRINTD (DBG_QOS, "actual rate: %u", *actual);
                }
                return 0;
   // Set the max AAL5 cell count to be just enough to contain the
   // largest AAL5 frame that the user wants to receive
   wr_regw (dev, MAX_AAL5_CELL_COUNT_OFF,
-          (max_rx_size + ATM_AAL5_TRAILER + ATM_CELL_PAYLOAD - 1) / ATM_CELL_PAYLOAD);
+          DIV_ROUND_UP(max_rx_size + ATM_AAL5_TRAILER, ATM_CELL_PAYLOAD));
   
   // Enable receive
   wr_regw (dev, RX_CONFIG_OFF, rd_regw (dev, RX_CONFIG_OFF) | RX_ENABLE);
 
                        vcc->qos.rxtp.max_sdu = 65464;
                        /* fix this - we may want to receive 64kB SDUs
                           later */
-               cells = (vcc->qos.rxtp.max_sdu+ATM_AAL5_TRAILER+
-                   ATM_CELL_PAYLOAD-1)/ATM_CELL_PAYLOAD;
+               cells = DIV_ROUND_UP(vcc->qos.rxtp.max_sdu + ATM_AAL5_TRAILER,
+                               ATM_CELL_PAYLOAD);
                zatm_vcc->pool = pool_index(cells*ATM_CELL_PAYLOAD);
        }
        else {
                        }
                        else {
                                i = 255;
-                               m = (ATM_OC3_PCR*255+max-1)/max;
+                               m = DIV_ROUND_UP(ATM_OC3_PCR*255, max);
                        }
                }
                if (i > m) {