iwlwifi: Add TFD library operations

The TFD structures for 3945 and agn HWs are fundamentally different. We thus
need to define operations for attaching and freeing them. This will allow us
to share a fair amount of code (cmd and tx queue related) between both
drivers.

Signed-off-by: Samuel Ortiz <samuel.ortiz@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 120 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index 7e0baf6deed..4a15e42ad00 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -471,6 +471,126 @@ static int iwl_send_beacon_cmd(struct iwl_priv *priv)
 	return rc;
 }
 
+static inline dma_addr_t iwl_tfd_tb_get_addr(struct iwl_tfd *tfd, u8 idx)
+{
+	struct iwl_tfd_tb *tb = &tfd->tbs[idx];
+
+	dma_addr_t addr = get_unaligned_le32(&tb->lo);
+	if (sizeof(dma_addr_t) > sizeof(u32))
+		addr |=
+		((dma_addr_t)(le16_to_cpu(tb->hi_n_len) & 0xF) << 16) << 16;
+
+	return addr;
+}
+
+static inline u16 iwl_tfd_tb_get_len(struct iwl_tfd *tfd, u8 idx)
+{
+	struct iwl_tfd_tb *tb = &tfd->tbs[idx];
+
+	return le16_to_cpu(tb->hi_n_len) >> 4;
+}
+
+static inline void iwl_tfd_set_tb(struct iwl_tfd *tfd, u8 idx,
+				  dma_addr_t addr, u16 len)
+{
+	struct iwl_tfd_tb *tb = &tfd->tbs[idx];
+	u16 hi_n_len = len << 4;
+
+	put_unaligned_le32(addr, &tb->lo);
+	if (sizeof(dma_addr_t) > sizeof(u32))
+		hi_n_len |= ((addr >> 16) >> 16) & 0xF;
+
+	tb->hi_n_len = cpu_to_le16(hi_n_len);
+
+	tfd->num_tbs = idx + 1;
+}
+
+static inline u8 iwl_tfd_get_num_tbs(struct iwl_tfd *tfd)
+{
+	return tfd->num_tbs & 0x1f;
+}
+
+/**
+ * iwl_hw_txq_free_tfd - Free all chunks referenced by TFD [txq->q.read_ptr]
+ * @priv - driver private data
+ * @txq - tx queue
+ *
+ * Does NOT advance any TFD circular buffer read/write indexes
+ * Does NOT free the TFD itself (which is within circular buffer)
+ */
+void iwl_hw_txq_free_tfd(struct iwl_priv *priv, struct iwl_tx_queue *txq)
+{
+	struct iwl_tfd *tfd_tmp = (struct iwl_tfd *)&txq->tfds[0];
+	struct iwl_tfd *tfd;
+	struct pci_dev *dev = priv->pci_dev;
+	int index = txq->q.read_ptr;
+	int i;
+	int num_tbs;
+
+	tfd = &tfd_tmp[index];
+
+	/* Sanity check on number of chunks */
+	num_tbs = iwl_tfd_get_num_tbs(tfd);
+
+	if (num_tbs >= IWL_NUM_OF_TBS) {
+		IWL_ERR(priv, "Too many chunks: %i\n", num_tbs);
+		/* @todo issue fatal error, it is quite serious situation */
+		return;
+	}
+
+	/* Unmap tx_cmd */
+	if (num_tbs)
+		pci_unmap_single(dev,
+				pci_unmap_addr(&txq->cmd[index]->meta, mapping),
+				pci_unmap_len(&txq->cmd[index]->meta, len),
+				PCI_DMA_TODEVICE);
+
+	/* Unmap chunks, if any. */
+	for (i = 1; i < num_tbs; i++) {
+		pci_unmap_single(dev, iwl_tfd_tb_get_addr(tfd, i),
+				iwl_tfd_tb_get_len(tfd, i), PCI_DMA_TODEVICE);
+
+		if (txq->txb) {
+			dev_kfree_skb(txq->txb[txq->q.read_ptr].skb[i - 1]);
+			txq->txb[txq->q.read_ptr].skb[i - 1] = NULL;
+		}
+	}
+}
+
+int iwl_hw_txq_attach_buf_to_tfd(struct iwl_priv *priv,
+				 struct iwl_tx_queue *txq,
+				 dma_addr_t addr, u16 len,
+				 u8 reset, u8 pad)
+{
+	struct iwl_queue *q;
+	struct iwl_tfd *tfd;
+	u32 num_tbs;
+
+	q = &txq->q;
+	tfd = &txq->tfds[q->write_ptr];
+
+	if (reset)
+		memset(tfd, 0, sizeof(*tfd));
+
+	num_tbs = iwl_tfd_get_num_tbs(tfd);
+
+	/* Each TFD can point to a maximum 20 Tx buffers */
+	if (num_tbs >= IWL_NUM_OF_TBS) {
+		IWL_ERR(priv, "Error can not send more than %d chunks\n",
+			  IWL_NUM_OF_TBS);
+		return -EINVAL;
+	}
+
+	BUG_ON(addr & ~DMA_BIT_MASK(36));
+	if (unlikely(addr & ~IWL_TX_DMA_MASK))
+		IWL_ERR(priv, "Unaligned address = %llx\n",
+			  (unsigned long long)addr);
+
+	iwl_tfd_set_tb(tfd, num_tbs, addr, len);
+
+	return 0;
+}
+
 /******************************************************************************
  *
  * Misc. internal state and helper functions