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Commit f4feb8ac authored by Johannes Berg's avatar Johannes Berg
Browse files

iwlwifi: support host command with copied data 



In addition to the NOCOPY flag, add a DUP flag that
tells the transport to kmemdup() the buffer and free
it after the command completes.

Currently this is only supported for a single buffer
in a given command, but that could be extended if it
should be needed.

Reviewed-by: default avatarEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 86052a77

drivers/net/wireless/iwlwifi/iwl-trans.h

+5 −1
Original line number Diff line number Diff line
@@ -221,14 +221,18 @@ struct iwl_device_cmd { 
/**

 * struct iwl_hcmd_dataflag - flag for each one of the chunks of the command

 *

 * IWL_HCMD_DFL_NOCOPY: By default, the command is copied to the host command's

 * @IWL_HCMD_DFL_NOCOPY: By default, the command is copied to the host command's

 *	ring. The transport layer doesn't map the command's buffer to DMA, but

 *	rather copies it to an previously allocated DMA buffer. This flag tells

 *	the transport layer not to copy the command, but to map the existing

 *	buffer. This can save memcpy and is worth with very big comamnds.

 * @IWL_HCMD_DFL_DUP: Only valid without NOCOPY, duplicate the memory for this

 *	chunk internally and free it again after the command completes. This

 *	can (currently) be used only once per command.

 */

enum iwl_hcmd_dataflag {

	IWL_HCMD_DFL_NOCOPY	= BIT(0),

	IWL_HCMD_DFL_DUP	= BIT(1),

};



/**

drivers/net/wireless/iwlwifi/pcie/internal.h

+2 −0
Original line number Diff line number Diff line
@@ -186,6 +186,8 @@ struct iwl_pcie_tx_queue_entry { 
	struct iwl_device_cmd *cmd;

	struct iwl_device_cmd *copy_cmd;

	struct sk_buff *skb;

	/* buffer to free after command completes */

	const void *free_buf;

	struct iwl_cmd_meta meta;

};

drivers/net/wireless/iwlwifi/pcie/rx.c

+3 −0
Original line number Diff line number Diff line
@@ -452,6 +452,9 @@ static void iwl_rx_handle_rxbuf(struct iwl_trans *trans, 
			/* The original command isn't needed any more */

			kfree(txq->entries[cmd_index].copy_cmd);

			txq->entries[cmd_index].copy_cmd = NULL;

			/* nor is the duplicated part of the command */

			kfree(txq->entries[cmd_index].free_buf);

			txq->entries[cmd_index].free_buf = NULL;

		}



		/*

drivers/net/wireless/iwlwifi/pcie/trans.c

+1 −0
Original line number Diff line number Diff line
@@ -496,6 +496,7 @@ static void iwl_tx_queue_free(struct iwl_trans *trans, int txq_id) 
		for (i = 0; i < txq->q.n_window; i++) {

			kfree(txq->entries[i].cmd);

			kfree(txq->entries[i].copy_cmd);

			kfree(txq->entries[i].free_buf);

		}



	/* De-alloc circular buffer of TFDs */

drivers/net/wireless/iwlwifi/pcie/tx.c

+48 −9
Original line number Diff line number Diff line
@@ -517,8 +517,9 @@ static int iwl_enqueue_hcmd(struct iwl_trans *trans, struct iwl_host_cmd *cmd) 
	struct iwl_queue *q = &txq->q;

	struct iwl_device_cmd *out_cmd;

	struct iwl_cmd_meta *out_meta;

	void *dup_buf = NULL;

	dma_addr_t phys_addr;

	u32 idx;

	int idx;

	u16 copy_size, cmd_size;

	bool had_nocopy = false;

	int i;
@@ -535,10 +536,33 @@ static int iwl_enqueue_hcmd(struct iwl_trans *trans, struct iwl_host_cmd *cmd) 
			continue;

		if (cmd->dataflags[i] & IWL_HCMD_DFL_NOCOPY) {

			had_nocopy = true;

			if (WARN_ON(cmd->dataflags[i] & IWL_HCMD_DFL_DUP)) {

				idx = -EINVAL;

				goto free_dup_buf;

			}

		} else if (cmd->dataflags[i] & IWL_HCMD_DFL_DUP) {

			/*

			 * This is also a chunk that isn't copied

			 * to the static buffer so set had_nocopy.

			 */

			had_nocopy = true;



			/* only allowed once */

			if (WARN_ON(dup_buf)) {

				idx = -EINVAL;

				goto free_dup_buf;

			}



			dup_buf = kmemdup(cmd->data[i], cmd->len[i],

					  GFP_ATOMIC);

			if (!dup_buf)

				return -ENOMEM;

		} else {

			/* NOCOPY must not be followed by normal! */

			if (WARN_ON(had_nocopy))

				return -EINVAL;

			if (WARN_ON(had_nocopy)) {

				idx = -EINVAL;

				goto free_dup_buf;

			}

			copy_size += cmd->len[i];

		}

		cmd_size += cmd->len[i];
@@ -553,8 +577,10 @@ static int iwl_enqueue_hcmd(struct iwl_trans *trans, struct iwl_host_cmd *cmd) 
	if (WARN(copy_size > TFD_MAX_PAYLOAD_SIZE,

		 "Command %s (%#x) is too large (%d bytes)\n",

		 trans_pcie_get_cmd_string(trans_pcie, cmd->id),

		 cmd->id, copy_size))

		return -EINVAL;

		 cmd->id, copy_size)) {

		idx = -EINVAL;

		goto free_dup_buf;

	}



	spin_lock_bh(&txq->lock);
@@ -563,7 +589,8 @@ static int iwl_enqueue_hcmd(struct iwl_trans *trans, struct iwl_host_cmd *cmd) 


		IWL_ERR(trans, "No space in command queue\n");

		iwl_op_mode_cmd_queue_full(trans->op_mode);

		return -ENOSPC;

		idx = -ENOSPC;

		goto free_dup_buf;

	}



	idx = get_cmd_index(q, q->write_ptr);
@@ -587,7 +614,8 @@ static int iwl_enqueue_hcmd(struct iwl_trans *trans, struct iwl_host_cmd *cmd) 
	for (i = 0; i < IWL_MAX_CMD_TFDS; i++) {

		if (!cmd->len[i])

			continue;

		if (cmd->dataflags[i] & IWL_HCMD_DFL_NOCOPY)

		if (cmd->dataflags[i] & (IWL_HCMD_DFL_NOCOPY |

					 IWL_HCMD_DFL_DUP))

			break;

		memcpy((u8 *)out_cmd + cmd_pos, cmd->data[i], cmd->len[i]);

		cmd_pos += cmd->len[i];
@@ -629,11 +657,16 @@ static int iwl_enqueue_hcmd(struct iwl_trans *trans, struct iwl_host_cmd *cmd) 
	iwlagn_txq_attach_buf_to_tfd(trans, txq, phys_addr, copy_size, 1);



	for (i = 0; i < IWL_MAX_CMD_TFDS; i++) {

		const void *data = cmd->data[i];



		if (!cmd->len[i])

			continue;

		if (!(cmd->dataflags[i] & IWL_HCMD_DFL_NOCOPY))

		if (!(cmd->dataflags[i] & (IWL_HCMD_DFL_NOCOPY |

					   IWL_HCMD_DFL_DUP)))

			continue;

		phys_addr = dma_map_single(trans->dev, (void *)cmd->data[i],

		if (cmd->dataflags[i] & IWL_HCMD_DFL_DUP)

			data = dup_buf;

		phys_addr = dma_map_single(trans->dev, (void *)data,

					   cmd->len[i], DMA_BIDIRECTIONAL);

		if (dma_mapping_error(trans->dev, phys_addr)) {

			iwl_unmap_tfd(trans, out_meta,
@@ -648,6 +681,9 @@ static int iwl_enqueue_hcmd(struct iwl_trans *trans, struct iwl_host_cmd *cmd) 
	}



	out_meta->flags = cmd->flags;

	if (WARN_ON_ONCE(txq->entries[idx].free_buf))

		kfree(txq->entries[idx].free_buf);

	txq->entries[idx].free_buf = dup_buf;



	txq->need_update = 1;
@@ -664,6 +700,9 @@ static int iwl_enqueue_hcmd(struct iwl_trans *trans, struct iwl_host_cmd *cmd) 


 out:

	spin_unlock_bh(&txq->lock);

 free_dup_buf:

	if (idx < 0)

		kfree(dup_buf);

	return idx;

}