path: root/drivers/net/wireless/ath/ath10k/htc.c

// SPDX-License-Identifier: ISC
/*
 * Copyright (c) 2005-2011 Atheros Communications Inc.
 * Copyright (c) 2011-2017 Qualcomm Atheros, Inc.
 */

#include "core.h"
#include "hif.h"
#include "debug.h"

/********/
/* Send */
/********/

static void ath10k_htc_control_tx_complete(struct ath10k *ar,
					   struct sk_buff *skb)
{
	kfree_skb(skb);
}

static struct sk_buff *ath10k_htc_build_tx_ctrl_skb(void *ar)
{
	struct sk_buff *skb;
	struct ath10k_skb_cb *skb_cb;

	skb = dev_alloc_skb(ATH10K_HTC_CONTROL_BUFFER_SIZE);
	if (!skb)
		return NULL;

	skb_reserve(skb, 20); /* FIXME: why 20 bytes? */
	WARN_ONCE((unsigned long)skb->data & 3, "unaligned skb");

	skb_cb = ATH10K_SKB_CB(skb);
	memset(skb_cb, 0, sizeof(*skb_cb));

	ath10k_dbg(ar, ATH10K_DBG_HTC, "%s: skb %pK\n", __func__, skb);
	return skb;
}

static inline void ath10k_htc_restore_tx_skb(struct ath10k_htc *htc,
					     struct sk_buff *skb)
{
	struct ath10k_skb_cb *skb_cb = ATH10K_SKB_CB(skb);

	if (htc->ar->bus_param.dev_type != ATH10K_DEV_TYPE_HL)
		dma_unmap_single(htc->ar->dev, skb_cb->paddr, skb->len, DMA_TO_DEVICE);
	skb_pull(skb, sizeof(struct ath10k_htc_hdr));
}

void ath10k_htc_notify_tx_completion(struct ath10k_htc_ep *ep,
				     struct sk_buff *skb)
{
	struct ath10k *ar = ep->htc->ar;

	ath10k_dbg(ar, ATH10K_DBG_HTC, "%s: ep %d skb %pK\n", __func__,
		   ep->eid, skb);

	ath10k_htc_restore_tx_skb(ep->htc, skb);

	if (!ep->ep_ops.ep_tx_complete) {
		ath10k_warn(ar, "no tx handler for eid %d\n", ep->eid);
		dev_kfree_skb_any(skb);
		return;
	}

	ep->ep_ops.ep_tx_complete(ep->htc->ar, skb);
}
EXPORT_SYMBOL(ath10k_htc_notify_tx_completion);

static void ath10k_htc_prepare_tx_skb(struct ath10k_htc_ep *ep,
				      struct sk_buff *skb)
{
	struct ath10k_htc_hdr *hdr;

	hdr = (struct ath10k_htc_hdr *)skb->data;

	hdr->eid = ep->eid;
	hdr->len = __cpu_to_le16(skb->len - sizeof(*hdr));
	hdr->flags = 0;
	if (ep->tx_credit_flow_enabled)
		hdr->flags |= ATH10K_HTC_FLAG_NEED_CREDIT_UPDATE;

	spin_lock_bh(&ep->htc->tx_lock);
	hdr->seq_no = ep->seq_no++;
	spin_unlock_bh(&ep->htc->tx_lock);
}

int ath10k_htc_send(struct ath10k_htc *htc,
		    enum ath10k_htc_ep_id eid,
		    struct sk_buff *skb)
{
	struct ath10k *ar = htc->ar;
	struct ath10k_htc_ep *ep = &htc->endpoint[eid];
	struct ath10k_skb_cb *skb_cb = ATH10K_SKB_CB(skb);
	struct ath10k_hif_sg_item sg_item;
	struct device *dev = htc->ar->dev;
	int credits = 0;
	int ret;

	if (htc->ar->state == ATH10K_STATE_WEDGED)
		return -ECOMM;

	if (eid >= ATH10K_HTC_EP_COUNT) {
		ath10k_warn(ar, "Invalid endpoint id: %d\n", eid);
		return -ENOENT;
	}

	skb_push(skb, sizeof(struct ath10k_htc_hdr));

	if (ep->tx_credit_flow_enabled) {
		credits = DIV_ROUND_UP(skb->len, htc->target_credit_size);
		spin_lock_bh(&htc->tx_lock);
		if (ep->tx_credits < credits) {
			ath10k_dbg(ar, ATH10K_DBG_HTC,
				   "htc insufficient credits ep %d required %d available %d\n",
				   eid, credits, ep->tx_credits);
			spin_unlock_bh(&htc->tx_lock);
			ret = -EAGAIN;
			goto err_pull;
		}
		ep->tx_credits -= credits;
		ath10k_dbg(ar, ATH10K_DBG_HTC,
			   "htc ep %d consumed %d credits (total %d)\n",
			   eid, credits, ep->tx_credits);
		spin_unlock_bh(&htc->tx_lock);
	}

	ath10k_htc_prepare_tx_skb(ep, skb);

	skb_cb->eid = eid;
	if (ar->bus_param.dev_type != ATH10K_DEV_TYPE_HL) {
		skb_cb->paddr = dma_map_single(dev, skb->data, skb->len,
					       DMA_TO_DEVICE);
		ret = dma_mapping_error(dev, skb_cb->paddr);
		if (ret) {
			ret = -EIO;
			goto err_credits;
		}
	}

	sg_item.transfer_id = ep->eid;
	sg_item.transfer_context = skb;
	sg_item.vaddr = skb->data;
	sg_item.paddr = skb_cb->paddr;
	sg_item.len = skb->len;

	ret = ath10k_hif_tx_sg(htc->ar, ep->ul_pipe_id, &sg_item, 1);
	if (ret)
		goto err_unmap;

	return 0;

err_unmap:
	if (ar->bus_param.dev_type != ATH10K_DEV_TYPE_HL)
		dma_unmap_single(dev, skb_cb->paddr, skb->len, DMA_TO_DEVICE);
err_credits:
	if (ep->tx_credit_flow_enabled) {
		spin_lock_bh(&htc->tx_lock);
		ep->tx_credits += credits;
		ath10k_dbg(ar, ATH10K_DBG_HTC,
			   "htc ep %d reverted %d credits back (total %d)\n",
			   eid, credits, ep->tx_credits);
		spin_unlock_bh(&htc->tx_lock);

		if (