[PATCH] ipw2200: stack reduction

Checking the stack usage of my kernel, showed that ipw2200 had a few bad
offenders. This is on i386 32-bit:

0x00002876 ipw_send_associate:                          544
0x000028ee ipw_send_associate:                          544
0x000027dc ipw_send_scan_request_ext:                   520
0x00002864 ipw_set_sensitivity:                         520
0x00005eac ipw_set_rsn_capa:                            520

The reason is the host_cmd structure is large (500 bytes). All other
functions currently using ipw_send_cmd() suffer from the same problem.
This patch introduces ipw_send_cmd_simple() for commands with no data
transfer, and ipw_send_cmd_pdu() for commands with a data payload and
makes the payload a pointer to the buffer passed in from the caller.

As an added bonus, the diffstat looks like this:

 ipw2200.c |  260 +++++++++++++++++++++-----------------------------------------
 ipw2200.h |    2
 2 files changed, 92 insertions(+), 170 deletions(-)

and it shrinks the module a lot as well:

Before:

   text    data     bss     dec     hex filename
  75177    2472      44   77693   12f7d drivers/net/wireless/ipw2200.ko

After:

   text    data     bss     dec     hex filename
  61363    2488      44   63895    f997 drivers/net/wireless/ipw2200.ko

So about a ~18% reduction in module size.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 91 insertions, 164 deletions

diff --git a/drivers/net/wireless/ipw2200.c b/drivers/net/wireless/ipw2200.c
index c42eb54f379a..2fe1e048328e 100644
--- a/drivers/net/wireless/ipw2200.c
+++ b/drivers/net/wireless/ipw2200.c
@@ -1928,7 +1928,8 @@ static char *get_cmd_string(u8 cmd)
 }
 
 #define HOST_COMPLETE_TIMEOUT HZ
-static int ipw_send_cmd(struct ipw_priv *priv, struct host_cmd *cmd)
+
+static int __ipw_send_cmd(struct ipw_priv *priv, struct host_cmd *cmd)
 {
         int rc = 0;
         unsigned long flags;
@@ -1964,7 +1965,7 @@ static int ipw_send_cmd(struct ipw_priv *priv, struct host_cmd *cmd)
                 printk_buf(IPW_DL_HOST_COMMAND, (u8 *) cmd->param, cmd->len);
 
 
-        rc = ipw_queue_tx_hcmd(priv, cmd->cmd, &cmd->param, cmd->len, 0);
+        rc = ipw_queue_tx_hcmd(priv, cmd->cmd, cmd->param, cmd->len, 0);
         if (rc) {
                 priv->status &= ~STATUS_HCMD_ACTIVE;
                 IPW_ERROR("Failed to send %s: Reason %d\n",
@@ -1999,7 +2000,7 @@ static int ipw_send_cmd(struct ipw_priv *priv, struct host_cmd *cmd)
                 goto exit;
         }
 
-      exit:
+exit:
         if (priv->cmdlog) {
                 priv->cmdlog[priv->cmdlog_pos++].retcode = rc;
                 priv->cmdlog_pos %= priv->cmdlog_len;
@@ -2007,61 +2008,62 @@ static int ipw_send_cmd(struct ipw_priv *priv, struct host_cmd *cmd)
         return rc;
 }
 
-static int ipw_send_host_complete(struct ipw_priv *priv)
+static int ipw_send_cmd_simple(struct ipw_priv *priv, u8 command)
+{
+        struct host_cmd cmd = {
+                .cmd = command,
+        };
+
+        return __ipw_send_cmd(priv, &cmd);
+}
+
+static int ipw_send_cmd_pdu(struct ipw_priv *priv, u8 command, u8 len,
+                            void *data)
 {
         struct host_cmd cmd = {
-                .cmd = IPW_CMD_HOST_COMPLETE,
-                .len = 0
+                .cmd = command,
+                .len = len,
+                .param = data,
         };
 
+        return __ipw_send_cmd(priv, &cmd);
+}
+
+static int ipw_send_host_complete(struct ipw_priv *priv)
+{
         if (!priv) {
                 IPW_ERROR("Invalid args\n");
                 return -1;
         }
 
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_simple(priv, IPW_CMD_HOST_COMPLETE);
 }
 
 static int ipw_send_system_config(struct ipw_priv *priv,
                                   struct ipw_sys_config *config)
 {
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_SYSTEM_CONFIG,
-                .len = sizeof(*config)
-        };
-
         if (!priv || !config) {
                 IPW_ERROR("Invalid args\n");
                 return -1;
         }
 
-        memcpy(cmd.param, config, sizeof(*config));
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_SYSTEM_CONFIG, sizeof(*config),
+                                        config);
 }
 
 static int ipw_send_ssid(struct ipw_priv *priv, u8 * ssid, int len)
 {
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_SSID,
-                .len = min(len, IW_ESSID_MAX_SIZE)
-        };
-
         if (!priv || !ssid) {
                 IPW_ERROR("Invalid args\n");
                 return -1;
         }
 
-        memcpy(cmd.param, ssid, cmd.len);
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_SSID, min(len, IW_ESSID_MAX_SIZE),
+                                        ssid);
 }
 
 static int ipw_send_adapter_address(struct ipw_priv *priv, u8 * mac)
 {
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_ADAPTER_ADDRESS,
-                .len = ETH_ALEN
-        };
-
         if (!priv || !mac) {
                 IPW_ERROR("Invalid args\n");
                 return -1;
@@ -2070,8 +2072,8 @@ static int ipw_send_adapter_address(struct ipw_priv *priv, u8 * mac)
         IPW_DEBUG_INFO("%s: Setting MAC to " MAC_FMT "\n",
                        priv->net_dev->name, MAC_ARG(mac));
 
-        memcpy(cmd.param, mac, ETH_ALEN);
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_ADAPTER_ADDRESS, ETH_ALEN,
+                                        mac);
 }
 
 /*
@@ -2130,51 +2132,40 @@ static void ipw_bg_scan_check(void *data)
 static int ipw_send_scan_request_ext(struct ipw_priv *priv,
                                      struct ipw_scan_request_ext *request)
 {
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_SCAN_REQUEST_EXT,
-                .len = sizeof(*request)
-        };
-
-        memcpy(cmd.param, request, sizeof(*request));
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_SCAN_REQUEST_EXT,
+                                        sizeof(*request), request);
 }
 
 static int ipw_send_scan_abort(struct ipw_priv *priv)
 {
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_SCAN_ABORT,
-                .len = 0
-        };
-
         if (!priv) {
                 IPW_ERROR("Invalid args\n");
                 return -1;
         }
 
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_simple(priv, IPW_CMD_SCAN_ABORT);
 }
 
 static int ipw_set_sensitivity(struct ipw_priv *priv, u16 sens)
 {
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_SENSITIVITY_CALIB,
-                .len = sizeof(struct ipw_sensitivity_calib)
+        struct ipw_sensitivity_calib calib = {
+                .beacon_rssi_raw = sens,
         };
-        struct ipw_sensitivity_calib *calib = (struct ipw_sensitivity_calib *)
-            &cmd.param;
-        calib->beacon_rssi_raw = sens;
-        return ipw_send_cmd(priv, &cmd);
+
+        return ipw_send_cmd_pdu(priv, IPW_CMD_SENSITIVITY_CALIB, sizeof(calib),
+                                        &calib);
 }
 
 static int ipw_send_associate(struct ipw_priv *priv,
                               struct ipw_associate *associate)
 {
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_ASSOCIATE,
-                .len = sizeof(*associate)
-        };
-
         struct ipw_associate tmp_associate;
+
+        if (!priv || !associate) {
+                IPW_ERROR("Invalid args\n");
+                return -1;
+        }
+
         memcpy(&tmp_associate, associate, sizeof(*associate));
         tmp_associate.policy_support =
             cpu_to_le16(tmp_associate.policy_support);
@@ -2187,80 +2178,56 @@ static int ipw_send_associate(struct ipw_priv *priv,
             cpu_to_le16(tmp_associate.beacon_interval);
         tmp_associate.atim_window = cpu_to_le16(tmp_associate.atim_window);
 
-        if (!priv || !associate) {
-                IPW_ERROR("Invalid args\n");
-                return -1;
-        }
-
-        memcpy(cmd.param, &tmp_associate, sizeof(*associate));
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_ASSOCIATE, sizeof(tmp_associate),
+                                        &tmp_associate);
 }
 
 static int ipw_send_supported_rates(struct ipw_priv *priv,
                                     struct ipw_supported_rates *rates)
 {
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_SUPPORTED_RATES,
-                .len = sizeof(*rates)
-        };
-
         if (!priv || !rates) {
                 IPW_ERROR("Invalid args\n");
                 return -1;
         }
 
-        memcpy(cmd.param, rates, sizeof(*rates));
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_SUPPORTED_RATES, sizeof(*rates),
+                                        rates);
 }
 
 static int ipw_set_random_seed(struct ipw_priv *priv)
 {
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_SEED_NUMBER,
-                .len = sizeof(u32)
-        };
+        u32 val;
 
         if (!priv) {
                 IPW_ERROR("Invalid args\n");
                 return -1;
         }
 
-        get_random_bytes(&cmd.param, sizeof(u32));
+        get_random_bytes(&val, sizeof(val));
 
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_SEED_NUMBER, sizeof(val), &val);
 }
 
 static int ipw_send_card_disable(struct ipw_priv *priv, u32 phy_off)
 {
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_CARD_DISABLE,
-                .len = sizeof(u32)
-        };
-
         if (!priv) {
                 IPW_ERROR("Invalid args\n");
                 return -1;
         }
 
-        *((u32 *) & cmd.param) = phy_off;
-
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_CARD_DISABLE, sizeof(phy_off),
+                                        &phy_off);
 }
 
 static int ipw_send_tx_power(struct ipw_priv *priv, struct ipw_tx_power *power)
 {
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_TX_POWER,
-                .len = sizeof(*power)
-        };
-
         if (!priv || !power) {
                 IPW_ERROR("Invalid args\n");
                 return -1;
         }
 
-        memcpy(cmd.param, power, sizeof(*power));
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_TX_POWER, sizeof(*power),
+                                        power);
 }
 
 static int ipw_set_tx_power(struct ipw_priv *priv)
@@ -2312,18 +2279,14 @@ static int ipw_send_rts_threshold(struct ipw_priv *priv, u16 rts)
         struct ipw_rts_threshold rts_threshold = {
                 .rts_threshold = rts,
         };
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_RTS_THRESHOLD,
-                .len = sizeof(rts_threshold)
-        };
 
         if (!priv) {
                 IPW_ERROR("Invalid args\n");
                 return -1;
         }
 
-        memcpy(cmd.param, &rts_threshold, sizeof(rts_threshold));
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_RTS_THRESHOLD,
+                                sizeof(rts_threshold), &rts_threshold);
 }
 
 static int ipw_send_frag_threshold(struct ipw_priv *priv, u16 frag)
@@ -2331,27 +2294,19 @@ static int ipw_send_frag_threshold(struct ipw_priv *priv, u16 frag)
         struct ipw_frag_threshold frag_threshold = {
                 .frag_threshold = frag,
         };
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_FRAG_THRESHOLD,
-                .len = sizeof(frag_threshold)
-        };
 
         if (!priv) {
                 IPW_ERROR("Invalid args\n");
                 return -1;
         }
 
-        memcpy(cmd.param, &frag_threshold, sizeof(frag_threshold));
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_FRAG_THRESHOLD,
+                                sizeof(frag_threshold), &frag_threshold);
 }
 
 static int ipw_send_power_mode(struct ipw_priv *priv, u32 mode)
 {
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_POWER_MODE,
-                .len = sizeof(u32)
-        };
-        u32 *param = (u32 *) (&cmd.param);
+        u32 param;
 
         if (!priv) {
                 IPW_ERROR("Invalid args\n");
@@ -2362,17 +2317,18 @@ static int ipw_send_power_mode(struct ipw_priv *priv, u32 mode)
          * level */
         switch (mode) {
         case IPW_POWER_BATTERY:
-                *param = IPW_POWER_INDEX_3;
+                param = IPW_POWER_INDEX_3;
                 break;
         case IPW_POWER_AC:
-                *param = IPW_POWER_MODE_CAM;
+                param = IPW_POWER_MODE_CAM;
                 break;
         default:
-                *param = mode;
+                param = mode;
                 break;
         }
 
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_POWER_MODE, sizeof(param),
+                                        &param);
 }
 
 static int ipw_send_retry_limit(struct ipw_priv *priv, u8 slimit, u8 llimit)
@@ -2381,18 +2337,14 @@ static int ipw_send_retry_limit(struct ipw_priv *priv, u8 slimit, u8 llimit)
                 .short_retry_limit = slimit,
                 .long_retry_limit = llimit
         };
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_RETRY_LIMIT,
-                .len = sizeof(retry_limit)
-        };
 
         if (!priv) {
                 IPW_ERROR("Invalid args\n");
                 return -1;
         }
 
-        memcpy(cmd.param, &retry_limit, sizeof(retry_limit));
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_RETRY_LIMIT, sizeof(retry_limit),
+                                        &retry_limit);
 }
 
 /*
@@ -5750,54 +5702,44 @@ static void ipw_adhoc_create(struct ipw_priv *priv,
 
 static void ipw_send_tgi_tx_key(struct ipw_priv *priv, int type, int index)
 {
-        struct ipw_tgi_tx_key *key;
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_TGI_TX_KEY,
-                .len = sizeof(*key)
-        };
+        struct ipw_tgi_tx_key key;
 
         if (!(priv->ieee->sec.flags & (1 << index)))
                 return;
 
-        key = (struct ipw_tgi_tx_key *)&cmd.param;
-        key->key_id = index;
-        memcpy(key->key, priv->ieee->sec.keys[index], SCM_TEMPORAL_KEY_LENGTH);
-        key->security_type = type;
-        key->station_index = 0; /* always 0 for BSS */
-        key->flags = 0;
+        key.key_id = index;
+        memcpy(key.key, priv->ieee->sec.keys[index], SCM_TEMPORAL_KEY_LENGTH);
+        key.security_type = type;
+        key.station_index = 0;  /* always 0 for BSS */
+        key.flags = 0;
         /* 0 for new key; previous value of counter (after fatal error) */
-        key->tx_counter[0] = 0;
-        key->tx_counter[1] = 0;
+        key.tx_counter[0] = 0;
+        key.tx_counter[1] = 0;
 
-        ipw_send_cmd(priv, &cmd);
+        ipw_send_cmd_pdu(priv, IPW_CMD_TGI_TX_KEY, sizeof(key), &key);
 }
 
 static void ipw_send_wep_keys(struct ipw_priv *priv, int type)
 {
-        struct ipw_wep_key *key;
+        struct ipw_wep_key key;
         int i;
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_WEP_KEY,
-                .len = sizeof(*key)
-        };
 
-        key = (struct ipw_wep_key *)&cmd.param;
-        key->cmd_id = DINO_CMD_WEP_KEY;
-        key->seq_num = 0;
+        key.cmd_id = DINO_CMD_WEP_KEY;
+        key.seq_num = 0;
 
         /* Note: AES keys cannot be set for multiple times.
          * Only set it at the first time. */
         for (i = 0; i < 4; i++) {
-                key->key_index = i | type;
+                key.key_index = i | type;
                 if (!(priv->ieee->sec.flags & (1 << i))) {
-                        key->key_size = 0;
+                        key.key_size = 0;
                         continue;
                 }
 
-                key->key_size = priv->ieee->sec.key_sizes[i];
-                memcpy(key->key, priv->ieee->sec.keys[i], key->key_size);
+                key.key_size = priv->ieee->sec.key_sizes[i];
+                memcpy(key.key, priv->ieee->sec.keys[i], key.key_size);
 
-                ipw_send_cmd(priv, &cmd);
+                ipw_send_cmd_pdu(priv, IPW_CMD_WEP_KEY, sizeof(key), &key);
         }
 }
 
@@ -6298,15 +6240,10 @@ static void ipw_wpa_assoc_frame(struct ipw_priv *priv, char *wpa_ie,
 static int ipw_set_rsn_capa(struct ipw_priv *priv,
                             char *capabilities, int length)
 {
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_RSN_CAPABILITIES,
-                .len = length,
-        };
-
         IPW_DEBUG_HC("HOST_CMD_RSN_CAPABILITIES\n");
 
-        memcpy(cmd.param, capabilities, length);
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_RSN_CAPABILITIES, length,
+                                        capabilities);
 }
 
 /*
@@ -7093,25 +7030,15 @@ static int ipw_handle_assoc_response(struct net_device *dev,
 static int ipw_send_qos_params_command(struct ipw_priv *priv, struct ieee80211_qos_parameters
                                        *qos_param)
 {
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_QOS_PARAMETERS,
-                .len = (sizeof(struct ieee80211_qos_parameters) * 3)
-        };
-
-        memcpy(cmd.param, qos_param, sizeof(*qos_param) * 3);
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_QOS_PARAMETERS, qos_param,
+                                        sizeof(*qos_param) * 3);
 }
 
 static int ipw_send_qos_info_command(struct ipw_priv *priv, struct ieee80211_qos_information_element
                                      *qos_param)
 {
-        struct host_cmd cmd = {
-                .cmd = IPW_CMD_WME_INFO,
-                .len = sizeof(*qos_param)
-        };
-
-        memcpy(cmd.param, qos_param, sizeof(*qos_param));
-        return ipw_send_cmd(priv, &cmd);
+        return ipw_send_cmd_pdu(priv, IPW_CMD_WME_INFO, qos_param,
+                                        sizeof(*qos_param));
 }
 
 #endif                          /* CONFIG_IPW_QOS */
diff --git a/drivers/net/wireless/ipw2200.h b/drivers/net/wireless/ipw2200.h
index 04a0c26cab84..c09888b1f1f8 100644
--- a/drivers/net/wireless/ipw2200.h
+++ b/drivers/net/wireless/ipw2200.h
@@ -1866,7 +1866,7 @@ struct host_cmd {
         u8 cmd;
         u8 len;
         u16 reserved;
-        u32 param[TFD_CMD_IMMEDIATE_PAYLOAD_LENGTH];
+        u32 *param;
 } __attribute__ ((packed));
 
 struct ipw_cmd_log {