iwlagn: check DMA mapping errors

DMA mappings can fail, but the current code
doesn't check for that. Add checking, which
requires some restructuring for proper error
paths.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>

2 files changed, 45 insertions, 28 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
index 26601b7048f2..7c1becf9e2c1 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-tx.c
@@ -537,7 +537,7 @@ int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
         struct iwl_tx_cmd *tx_cmd;
         struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
         int txq_id;
-        dma_addr_t phys_addr;
+        dma_addr_t phys_addr = 0;
         dma_addr_t txcmd_phys;
         dma_addr_t scratch_phys;
         u16 len, firstlen, secondlen;
@@ -564,7 +564,7 @@ int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
         spin_lock_irqsave(&priv->lock, flags);
         if (iwl_is_rfkill(priv)) {
                 IWL_DEBUG_DROP(priv, "Dropping - RF KILL\n");
-                goto drop_unlock;
+                goto drop_unlock_priv;
         }
 
         fc = hdr->frame_control;
@@ -585,7 +585,7 @@ int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
         if (sta_id == IWL_INVALID_STATION) {
                 IWL_DEBUG_DROP(priv, "Dropping - INVALID STATION: %pM\n",
                                hdr->addr1);
-                goto drop_unlock;
+                goto drop_unlock_priv;
         }
 
         IWL_DEBUG_TX(priv, "station Id %d\n", sta_id);
@@ -628,10 +628,10 @@ int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
         if (ieee80211_is_data_qos(fc)) {
                 qc = ieee80211_get_qos_ctl(hdr);
                 tid = qc[0] & IEEE80211_QOS_CTL_TID_MASK;
-                if (WARN_ON_ONCE(tid >= MAX_TID_COUNT)) {
-                        spin_unlock(&priv->sta_lock);
-                        goto drop_unlock;
-                }
+
+                if (WARN_ON_ONCE(tid >= MAX_TID_COUNT))
+                        goto drop_unlock_sta;
+
                 seq_number = priv->stations[sta_id].tid[tid].seq_number;
                 seq_number &= IEEE80211_SCTL_SEQ;
                 hdr->seq_ctrl = hdr->seq_ctrl &
@@ -649,18 +649,8 @@ int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
         txq = &priv->txq[txq_id];
         q = &txq->q;
 
-        if (unlikely(iwl_queue_space(q) < q->high_mark)) {
-                spin_unlock(&priv->sta_lock);
-                goto drop_unlock;
-        }
-
-        if (ieee80211_is_data_qos(fc)) {
-                priv->stations[sta_id].tid[tid].tfds_in_queue++;
-                if (!ieee80211_has_morefrags(fc))
-                        priv->stations[sta_id].tid[tid].seq_number = seq_number;
-        }
-
-        spin_unlock(&priv->sta_lock);
+        if (unlikely(iwl_queue_space(q) < q->high_mark))
+                goto drop_unlock_sta;
 
         /* Set up driver data for this TFD */
         memset(&(txq->txb[q->write_ptr]), 0, sizeof(struct iwl_tx_info));
@@ -724,12 +714,10 @@ int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
         txcmd_phys = pci_map_single(priv->pci_dev,
                                     &out_cmd->hdr, firstlen,
                                     PCI_DMA_BIDIRECTIONAL);
+        if (unlikely(pci_dma_mapping_error(priv->pci_dev, txcmd_phys)))
+                goto drop_unlock_sta;
         dma_unmap_addr_set(out_meta, mapping, txcmd_phys);
         dma_unmap_len_set(out_meta, len, firstlen);
-        /* Add buffer containing Tx command and MAC(!) header to TFD's
-         * first entry */
-        priv->cfg->ops->lib->txq_attach_buf_to_tfd(priv, txq,
-                                                   txcmd_phys, firstlen, 1, 0);
 
         if (!ieee80211_has_morefrags(hdr->frame_control)) {
                 txq->need_update = 1;
@@ -744,10 +732,30 @@ int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
         if (secondlen > 0) {
                 phys_addr = pci_map_single(priv->pci_dev, skb->data + hdr_len,
                                            secondlen, PCI_DMA_TODEVICE);
+                if (unlikely(pci_dma_mapping_error(priv->pci_dev, phys_addr))) {
+                        pci_unmap_single(priv->pci_dev,
+                                         dma_unmap_addr(out_meta, mapping),
+                                         dma_unmap_len(out_meta, len),
+                                         PCI_DMA_BIDIRECTIONAL);
+                        goto drop_unlock_sta;
+                }
+        }
+
+        if (ieee80211_is_data_qos(fc)) {
+                priv->stations[sta_id].tid[tid].tfds_in_queue++;
+                if (!ieee80211_has_morefrags(fc))
+                        priv->stations[sta_id].tid[tid].seq_number = seq_number;
+        }
+
+        spin_unlock(&priv->sta_lock);
+
+        /* Attach buffers to TFD */
+        priv->cfg->ops->lib->txq_attach_buf_to_tfd(priv, txq,
+                                                   txcmd_phys, firstlen, 1, 0);
+        if (secondlen > 0)
                 priv->cfg->ops->lib->txq_attach_buf_to_tfd(priv, txq,
                                                            phys_addr, secondlen,
                                                            0, 0);
-        }
 
         scratch_phys = txcmd_phys + sizeof(struct iwl_cmd_header) +
                                 offsetof(struct iwl_tx_cmd, scratch);
@@ -813,7 +821,9 @@ int iwlagn_tx_skb(struct iwl_priv *priv, struct sk_buff *skb)
 
         return 0;
 
-drop_unlock:
+drop_unlock_sta:
+        spin_unlock(&priv->sta_lock);
+drop_unlock_priv:
         spin_unlock_irqrestore(&priv->lock, flags);
         return -1;
 }
diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c
index 5a7cd177fe5e..e69597ea43e2 100644
--- a/drivers/net/wireless/iwlwifi/iwl-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-tx.c
@@ -500,7 +500,6 @@ int iwl_enqueue_hcmd(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
         }
 
         memset(out_meta, 0, sizeof(*out_meta)); /* re-initialize to NULL */
-        out_meta->flags = cmd->flags | CMD_MAPPED;
         if (cmd->flags & CMD_WANT_SKB)
                 out_meta->source = cmd;
         if (cmd->flags & CMD_ASYNC)
@@ -538,13 +537,20 @@ int iwl_enqueue_hcmd(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
                                 q->write_ptr, idx, priv->cmd_queue);
         }
 #endif
-        txq->need_update = 1;
-
         phys_addr = pci_map_single(priv->pci_dev, &out_cmd->hdr,
                                    fix_size, PCI_DMA_BIDIRECTIONAL);
+        if (unlikely(pci_dma_mapping_error(priv->pci_dev, phys_addr))) {
+                idx = -ENOMEM;
+                goto out;
+        }
+
         dma_unmap_addr_set(out_meta, mapping, phys_addr);
         dma_unmap_len_set(out_meta, len, fix_size);
 
+        out_meta->flags = cmd->flags | CMD_MAPPED;
+
+        txq->need_update = 1;
+
         trace_iwlwifi_dev_hcmd(priv, &out_cmd->hdr, fix_size, cmd->flags);
 
         priv->cfg->ops->lib->txq_attach_buf_to_tfd(priv, txq,
@@ -555,6 +561,7 @@ int iwl_enqueue_hcmd(struct iwl_priv *priv, struct iwl_host_cmd *cmd)
         q->write_ptr = iwl_queue_inc_wrap(q->write_ptr, q->n_bd);
         iwl_txq_update_write_ptr(priv, txq);
 
+ out:
         spin_unlock_irqrestore(&priv->hcmd_lock, flags);
         return idx;
 }