e1000: rework module param code with uninitialized values

We can take uninitialized values into account which minimizes code
and allows us to simplify the parameter checking code greatly.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>

1 files changed, 61 insertions, 106 deletions

diff --git a/drivers/net/e1000/e1000_param.c b/drivers/net/e1000/e1000_param.c
index a8d9295b0779..bd6c040b3cfb 100644
--- a/drivers/net/e1000/e1000_param.c
+++ b/drivers/net/e1000/e1000_param.c
@@ -45,6 +45,16 @@
  */
 
 #define E1000_PARAM_INIT { [0 ... E1000_MAX_NIC] = OPTION_UNSET }
+/* Module Parameters are always initialized to -1, so that the driver
+ * can tell the difference between no user specified value or the
+ * user asking for the default value.
+ * The true default values are loaded in when e1000_check_options is called.
+ *
+ * This is a GCC extension to ANSI C.
+ * See the item "Labeled Elements in Initializers" in the section
+ * "Extensions to the C Language Family" of the GCC documentation.
+ */
+
 #define E1000_PARAM(X, desc) \
         static int __devinitdata X[E1000_MAX_NIC+1] = E1000_PARAM_INIT; \
         static int num_##X = 0; \
@@ -305,6 +315,7 @@ e1000_check_options(struct e1000_adapter *adapter)
                 DPRINTK(PROBE, NOTICE,
                        "Warning: no configuration for board #%i\n", bd);
                 DPRINTK(PROBE, NOTICE, "Using defaults for all values\n");
+                bd = E1000_MAX_NIC;
         }
 
         { /* Transmit Descriptor Count */
@@ -322,14 +333,9 @@ e1000_check_options(struct e1000_adapter *adapter)
                 opt.arg.r.max = mac_type < e1000_82544 ?
                         E1000_MAX_TXD : E1000_MAX_82544_TXD;
 
-                if (num_TxDescriptors > bd) {
-                        tx_ring->count = TxDescriptors[bd];
-                        e1000_validate_option(&tx_ring->count, &opt, adapter);
-                        E1000_ROUNDUP(tx_ring->count,
-                                                REQ_TX_DESCRIPTOR_MULTIPLE);
-                } else {
-                        tx_ring->count = opt.def;
-                }
+                tx_ring->count = TxDescriptors[bd];
+                e1000_validate_option(&tx_ring->count, &opt, adapter);
+                E1000_ROUNDUP(tx_ring->count, REQ_TX_DESCRIPTOR_MULTIPLE);
                 for (i = 0; i < adapter->num_tx_queues; i++)
                         tx_ring[i].count = tx_ring->count;
         }
@@ -348,14 +354,9 @@ e1000_check_options(struct e1000_adapter *adapter)
                 opt.arg.r.max = mac_type < e1000_82544 ? E1000_MAX_RXD :
                         E1000_MAX_82544_RXD;
 
-                if (num_RxDescriptors > bd) {
-                        rx_ring->count = RxDescriptors[bd];
-                        e1000_validate_option(&rx_ring->count, &opt, adapter);
-                        E1000_ROUNDUP(rx_ring->count,
-                                                REQ_RX_DESCRIPTOR_MULTIPLE);
-                } else {
-                        rx_ring->count = opt.def;
-                }
+                rx_ring->count = RxDescriptors[bd];
+                e1000_validate_option(&rx_ring->count, &opt, adapter);
+                E1000_ROUNDUP(rx_ring->count, REQ_RX_DESCRIPTOR_MULTIPLE);
                 for (i = 0; i < adapter->num_rx_queues; i++)
                         rx_ring[i].count = rx_ring->count;
         }
@@ -367,13 +368,9 @@ e1000_check_options(struct e1000_adapter *adapter)
                         .def  = OPTION_ENABLED
                 };
 
-                if (num_XsumRX > bd) {
-                        int rx_csum = XsumRX[bd];
-                        e1000_validate_option(&rx_csum, &opt, adapter);
-                        adapter->rx_csum = rx_csum;
-                } else {
-                        adapter->rx_csum = opt.def;
-                }
+                int rx_csum = XsumRX[bd];
+                e1000_validate_option(&rx_csum, &opt, adapter);
+                adapter->rx_csum = rx_csum;
         }
         { /* Flow Control */
 
@@ -393,13 +390,9 @@ e1000_check_options(struct e1000_adapter *adapter)
                                          .p = fc_list }}
                 };
 
-                if (num_FlowControl > bd) {
-                        int fc = FlowControl[bd];
-                        e1000_validate_option(&fc, &opt, adapter);
-                        adapter->hw.fc = adapter->hw.original_fc = fc;
-                } else {
-                        adapter->hw.fc = adapter->hw.original_fc = opt.def;
-                }
+                int fc = FlowControl[bd];
+                e1000_validate_option(&fc, &opt, adapter);
+                adapter->hw.fc = adapter->hw.original_fc = fc;
         }
         { /* Transmit Interrupt Delay */
                 struct e1000_option opt = {
@@ -411,13 +404,8 @@ e1000_check_options(struct e1000_adapter *adapter)
                                          .max = MAX_TXDELAY }}
                 };
 
-                if (num_TxIntDelay > bd) {
-                        adapter->tx_int_delay = TxIntDelay[bd];
-                        e1000_validate_option(&adapter->tx_int_delay, &opt,
-                                                                adapter);
-                } else {
-                        adapter->tx_int_delay = opt.def;
-                }
+                adapter->tx_int_delay = TxIntDelay[bd];
+                e1000_validate_option(&adapter->tx_int_delay, &opt, adapter);
         }
         { /* Transmit Absolute Interrupt Delay */
                 struct e1000_option opt = {
@@ -429,13 +417,9 @@ e1000_check_options(struct e1000_adapter *adapter)
                                          .max = MAX_TXABSDELAY }}
                 };
 
-                if (num_TxAbsIntDelay > bd) {
-                        adapter->tx_abs_int_delay = TxAbsIntDelay[bd];
-                        e1000_validate_option(&adapter->tx_abs_int_delay, &opt,
-                                                                adapter);
-                } else {
-                        adapter->tx_abs_int_delay = opt.def;
-                }
+                adapter->tx_abs_int_delay = TxAbsIntDelay[bd];
+                e1000_validate_option(&adapter->tx_abs_int_delay, &opt,
+                                      adapter);
         }
         { /* Receive Interrupt Delay */
                 struct e1000_option opt = {
@@ -447,13 +431,8 @@ e1000_check_options(struct e1000_adapter *adapter)
                                          .max = MAX_RXDELAY }}
                 };
 
-                if (num_RxIntDelay > bd) {
-                        adapter->rx_int_delay = RxIntDelay[bd];
-                        e1000_validate_option(&adapter->rx_int_delay, &opt,
-                                                                adapter);
-                } else {
-                        adapter->rx_int_delay = opt.def;
-                }
+                adapter->rx_int_delay = RxIntDelay[bd];
+                e1000_validate_option(&adapter->rx_int_delay, &opt, adapter);
         }
         { /* Receive Absolute Interrupt Delay */
                 struct e1000_option opt = {
@@ -465,13 +444,9 @@ e1000_check_options(struct e1000_adapter *adapter)
                                          .max = MAX_RXABSDELAY }}
                 };
 
-                if (num_RxAbsIntDelay > bd) {
-                        adapter->rx_abs_int_delay = RxAbsIntDelay[bd];
-                        e1000_validate_option(&adapter->rx_abs_int_delay, &opt,
-                                                                adapter);
-                } else {
-                        adapter->rx_abs_int_delay = opt.def;
-                }
+                adapter->rx_abs_int_delay = RxAbsIntDelay[bd];
+                e1000_validate_option(&adapter->rx_abs_int_delay, &opt,
+                                      adapter);
         }
         { /* Interrupt Throttling Rate */
                 struct e1000_option opt = {
@@ -483,24 +458,18 @@ e1000_check_options(struct e1000_adapter *adapter)
                                          .max = MAX_ITR }}
                 };
 
-                if (num_InterruptThrottleRate > bd) {
-                        adapter->itr = InterruptThrottleRate[bd];
-                        switch (adapter->itr) {
-                        case 0:
-                                DPRINTK(PROBE, INFO, "%s turned off\n",
-                                        opt.name);
-                                break;
-                        case 1:
-                                DPRINTK(PROBE, INFO, "%s set to dynamic mode\n",
-                                        opt.name);
-                                break;
-                        default:
-                                e1000_validate_option(&adapter->itr, &opt,
-                                        adapter);
-                                break;
-                        }
-                } else {
-                        adapter->itr = opt.def;
+                adapter->itr = InterruptThrottleRate[bd];
+                switch (adapter->itr) {
+                case 0:
+                        DPRINTK(PROBE, INFO, "%s turned off\n", opt.name);
+                        break;
+                case 1:
+                        DPRINTK(PROBE, INFO, "%s set to dynamic mode\n",
+                                opt.name);
+                        break;
+                default:
+                        e1000_validate_option(&adapter->itr, &opt, adapter);
+                        break;
                 }
         }
         { /* Smart Power Down */
@@ -511,13 +480,9 @@ e1000_check_options(struct e1000_adapter *adapter)
                         .def  = OPTION_DISABLED
                 };
 
-                if (num_SmartPowerDownEnable > bd) {
-                        int spd = SmartPowerDownEnable[bd];
-                        e1000_validate_option(&spd, &opt, adapter);
-                        adapter->smart_power_down = spd;
-                } else {
-                        adapter->smart_power_down = opt.def;
-                }
+                int spd = SmartPowerDownEnable[bd];
+                e1000_validate_option(&spd, &opt, adapter);
+                adapter->smart_power_down = spd;
         }
 
         switch (adapter->hw.media_type) {
@@ -544,17 +509,18 @@ static void __devinit
 e1000_check_fiber_options(struct e1000_adapter *adapter)
 {
         int bd = adapter->bd_number;
-        if (num_Speed > bd) {
+        bd = bd > E1000_MAX_NIC ? E1000_MAX_NIC : bd;
+        if ((Speed[bd] != OPTION_UNSET)) {
                 DPRINTK(PROBE, INFO, "Speed not valid for fiber adapters, "
                        "parameter ignored\n");
         }
 
-        if (num_Duplex > bd) {
+        if ((Duplex[bd] != OPTION_UNSET)) {
                 DPRINTK(PROBE, INFO, "Duplex not valid for fiber adapters, "
                        "parameter ignored\n");
         }
 
-        if ((num_AutoNeg > bd) && (AutoNeg[bd] != 0x20)) {
+        if ((AutoNeg[bd] != OPTION_UNSET) && (AutoNeg[bd] != 0x20)) {
                 DPRINTK(PROBE, INFO, "AutoNeg other than 1000/Full is "
                                  "not valid for fiber adapters, "
                                  "parameter ignored\n");
@@ -573,6 +539,7 @@ e1000_check_copper_options(struct e1000_adapter *adapter)
 {
         int speed, dplx, an;
         int bd = adapter->bd_number;
+        bd = bd > E1000_MAX_NIC ? E1000_MAX_NIC : bd;
 
         { /* Speed */
                 struct e1000_opt_list speed_list[] = {{          0, "" },
@@ -589,12 +556,8 @@ e1000_check_copper_options(struct e1000_adapter *adapter)
                                          .p = speed_list }}
                 };
 
-                if (num_Speed > bd) {
-                        speed = Speed[bd];
-                        e1000_validate_option(&speed, &opt, adapter);
-                } else {
-                        speed = opt.def;
-                }
+                speed = Speed[bd];
+                e1000_validate_option(&speed, &opt, adapter);
         }
         { /* Duplex */
                 struct e1000_opt_list dplx_list[] = {{           0, "" },
@@ -616,15 +579,11 @@ e1000_check_copper_options(struct e1000_adapter *adapter)
                                 "Speed/Duplex/AutoNeg parameter ignored.\n");
                         return;
                 }
-                if (num_Duplex > bd) {
-                        dplx = Duplex[bd];
-                        e1000_validate_option(&dplx, &opt, adapter);
-                } else {
-                        dplx = opt.def;
-                }
+                dplx = Duplex[bd];
+                e1000_validate_option(&dplx, &opt, adapter);
         }
 
-        if ((num_AutoNeg > bd) && (speed != 0 || dplx != 0)) {
+        if (AutoNeg[bd] != OPTION_UNSET && (speed != 0 || dplx != 0)) {
                 DPRINTK(PROBE, INFO,
                        "AutoNeg specified along with Speed or Duplex, "
                        "parameter ignored\n");
@@ -673,19 +632,15 @@ e1000_check_copper_options(struct e1000_adapter *adapter)
                                          .p = an_list }}
                 };
 
-                if (num_AutoNeg > bd) {
-                        an = AutoNeg[bd];
-                        e1000_validate_option(&an, &opt, adapter);
-                } else {
-                        an = opt.def;
-                }
+                an = AutoNeg[bd];
+                e1000_validate_option(&an, &opt, adapter);
                 adapter->hw.autoneg_advertised = an;
         }
 
         switch (speed + dplx) {
         case 0:
                 adapter->hw.autoneg = adapter->fc_autoneg = 1;
-                if ((num_Speed > bd) && (speed != 0 || dplx != 0))
+                if (Speed[bd] != OPTION_UNSET || Duplex[bd] != OPTION_UNSET)
                         DPRINTK(PROBE, INFO,
                                "Speed and duplex autonegotiation enabled\n");
                 break;