p54: refactor p54_alloc_skb

Old firmwares had no problems processing frames which filled eighth of the memory window.
However we have to be a bit more careful with fat frames when we talk to new firmwares.
Apart from that, I confess the old logic was a bit weird and not very sophisticated.

Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 33 insertions, 41 deletions

diff --git a/drivers/net/wireless/p54/p54common.c b/drivers/net/wireless/p54/p54common.c
index e463c7c3a7e0..c6dcf98aad3e 100644
--- a/drivers/net/wireless/p54/p54common.c
+++ b/drivers/net/wireless/p54/p54common.c
@@ -1104,25 +1104,29 @@ static int p54_assign_address(struct ieee80211_hw *dev, struct sk_buff *skb,
         return 0;
 }
 
-static struct sk_buff *p54_alloc_skb(struct ieee80211_hw *dev,
-                u16 hdr_flags, u16 len, u16 type, gfp_t memflags)
+static struct sk_buff *p54_alloc_skb(struct ieee80211_hw *dev, u16 hdr_flags,
+                                     u16 payload_len, u16 type, gfp_t memflags)
 {
         struct p54_common *priv = dev->priv;
         struct p54_hdr *hdr;
         struct sk_buff *skb;
+        size_t frame_len = sizeof(*hdr) + payload_len;
 
-        skb = __dev_alloc_skb(len + priv->tx_hdr_len, memflags);
+        if (frame_len > P54_MAX_CTRL_FRAME_LEN)
+                return NULL;
+
+        skb = __dev_alloc_skb(priv->tx_hdr_len + frame_len, memflags);
         if (!skb)
                 return NULL;
         skb_reserve(skb, priv->tx_hdr_len);
 
         hdr = (struct p54_hdr *) skb_put(skb, sizeof(*hdr));
         hdr->flags = cpu_to_le16(hdr_flags);
-        hdr->len = cpu_to_le16(len - sizeof(*hdr));
+        hdr->len = cpu_to_le16(payload_len);
         hdr->type = cpu_to_le16(type);
         hdr->tries = hdr->rts_tries = 0;
 
-        if (unlikely(p54_assign_address(dev, skb, hdr, len))) {
+        if (p54_assign_address(dev, skb, hdr, frame_len)) {
                 kfree_skb(skb);
                 return NULL;
         }
@@ -1132,7 +1136,6 @@ static struct sk_buff *p54_alloc_skb(struct ieee80211_hw *dev,
 int p54_read_eeprom(struct ieee80211_hw *dev)
 {
         struct p54_common *priv = dev->priv;
-        struct p54_hdr *hdr = NULL;
         struct p54_eeprom_lm86 *eeprom_hdr;
         struct sk_buff *skb;
         size_t eeprom_size = 0x2020, offset = 0, blocksize, maxblocksize;
@@ -1145,9 +1148,9 @@ int p54_read_eeprom(struct ieee80211_hw *dev)
         else
                 maxblocksize -= 0x4;
 
-        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL, sizeof(*hdr) +
-                            sizeof(*eeprom_hdr) + maxblocksize,
-                            P54_CONTROL_TYPE_EEPROM_READBACK, GFP_KERNEL);
+        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL, sizeof(*eeprom_hdr) +
+                            maxblocksize, P54_CONTROL_TYPE_EEPROM_READBACK,
+                            GFP_KERNEL);
         if (!skb)
                 goto free;
         priv->eeprom = kzalloc(EEPROM_READBACK_LEN, GFP_KERNEL);
@@ -1203,9 +1206,8 @@ static int p54_set_tim(struct ieee80211_hw *dev, struct ieee80211_sta *sta,
         struct sk_buff *skb;
         struct p54_tim *tim;
 
-        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET,
-                      sizeof(struct p54_hdr) + sizeof(*tim),
-                      P54_CONTROL_TYPE_TIM, GFP_ATOMIC);
+        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*tim),
+                            P54_CONTROL_TYPE_TIM, GFP_ATOMIC);
         if (!skb)
                 return -ENOMEM;
 
@@ -1222,9 +1224,8 @@ static int p54_sta_unlock(struct ieee80211_hw *dev, u8 *addr)
         struct sk_buff *skb;
         struct p54_sta_unlock *sta;
 
-        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET,
-                sizeof(struct p54_hdr) + sizeof(*sta),
-                P54_CONTROL_TYPE_PSM_STA_UNLOCK, GFP_ATOMIC);
+        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*sta),
+                            P54_CONTROL_TYPE_PSM_STA_UNLOCK, GFP_ATOMIC);
         if (!skb)
                 return -ENOMEM;
 
@@ -1264,9 +1265,8 @@ static int p54_tx_cancel(struct ieee80211_hw *dev, struct sk_buff *entry)
         struct p54_hdr *hdr;
         struct p54_txcancel *cancel;
 
-        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET,
-                sizeof(struct p54_hdr) + sizeof(*cancel),
-                P54_CONTROL_TYPE_TXCANCEL, GFP_ATOMIC);
+        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*cancel),
+                            P54_CONTROL_TYPE_TXCANCEL, GFP_ATOMIC);
         if (!skb)
                 return -ENOMEM;
 
@@ -1548,9 +1548,8 @@ static int p54_setup_mac(struct ieee80211_hw *dev)
         struct p54_setup_mac *setup;
         u16 mode;
 
-        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*setup) +
-                            sizeof(struct p54_hdr), P54_CONTROL_TYPE_SETUP,
-                            GFP_ATOMIC);
+        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*setup),
+                            P54_CONTROL_TYPE_SETUP, GFP_ATOMIC);
         if (!skb)
                 return -ENOMEM;
 
@@ -1628,9 +1627,8 @@ static int p54_scan(struct ieee80211_hw *dev, u16 mode, u16 dwell)
         __le16 freq = cpu_to_le16(dev->conf.channel->center_freq);
         int band = dev->conf.channel->band;
 
-        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*chan) +
-                            sizeof(struct p54_hdr), P54_CONTROL_TYPE_SCAN,
-                            GFP_ATOMIC);
+        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*chan),
+                            P54_CONTROL_TYPE_SCAN, GFP_ATOMIC);
         if (!skb)
                 return -ENOMEM;
 
@@ -1710,9 +1708,8 @@ static int p54_set_leds(struct ieee80211_hw *dev, int mode, int link, int act)
         struct sk_buff *skb;
         struct p54_led *led;
 
-        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*led) +
-                        sizeof(struct p54_hdr), P54_CONTROL_TYPE_LED,
-                        GFP_ATOMIC);
+        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*led),
+                            P54_CONTROL_TYPE_LED, GFP_ATOMIC);
         if (!skb)
                 return -ENOMEM;
 
@@ -1739,9 +1736,8 @@ static int p54_set_edcf(struct ieee80211_hw *dev)
         struct sk_buff *skb;
         struct p54_edcf *edcf;
 
-        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*edcf) +
-                        sizeof(struct p54_hdr), P54_CONTROL_TYPE_DCFINIT,
-                        GFP_ATOMIC);
+        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*edcf),
+                            P54_CONTROL_TYPE_DCFINIT, GFP_ATOMIC);
         if (!skb)
                 return -ENOMEM;
 
@@ -1778,9 +1774,8 @@ static int p54_set_ps(struct ieee80211_hw *dev)
         else
                 mode = P54_PSM_CAM;
 
-        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*psm) +
-                        sizeof(struct p54_hdr), P54_CONTROL_TYPE_PSM,
-                        GFP_ATOMIC);
+        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*psm),
+                            P54_CONTROL_TYPE_PSM, GFP_ATOMIC);
         if (!skb)
                 return -ENOMEM;
 
@@ -2083,10 +2078,8 @@ static int p54_init_xbow_synth(struct ieee80211_hw *dev)
         struct sk_buff *skb;
         struct p54_xbow_synth *xbow;
 
-        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*xbow) +
-                            sizeof(struct p54_hdr),
-                            P54_CONTROL_TYPE_XBOW_SYNTH_CFG,
-                            GFP_KERNEL);
+        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*xbow),
+                            P54_CONTROL_TYPE_XBOW_SYNTH_CFG, GFP_KERNEL);
         if (!skb)
                 return -ENOMEM;
 
@@ -2115,7 +2108,7 @@ static void p54_work(struct work_struct *work)
          *      2. cancel stuck frames / reset the device if necessary.
          */
 
-        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL, sizeof(struct p54_hdr) +
+        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL,
                             sizeof(struct p54_statistics),
                             P54_CONTROL_TYPE_STAT_READBACK, GFP_KERNEL);
         if (!skb)
@@ -2226,9 +2219,8 @@ static int p54_set_key(struct ieee80211_hw *dev, enum set_key_cmd cmd,
         }
 
         mutex_lock(&priv->conf_mutex);
-        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*rxkey) +
-                        sizeof(struct p54_hdr), P54_CONTROL_TYPE_RX_KEYCACHE,
-                        GFP_ATOMIC);
+        skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*rxkey),
+                            P54_CONTROL_TYPE_RX_KEYCACHE, GFP_ATOMIC);
         if (!skb) {
                 mutex_unlock(&priv->conf_mutex);
                 return -ENOMEM;