path: root/drivers/net/wireless/ath/ath11k/htc.c

// SPDX-License-Identifier: BSD-3-Clause-Clear
/*
 * Copyright (c) 2018-2019 The Linux Foundation. All rights reserved.
 * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
 */
#include <linux/skbuff.h>
#include <linux/ctype.h>

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

struct sk_buff *ath11k_htc_alloc_skb(struct ath11k_base *ab, int size)
{
	struct sk_buff *skb;

	skb = dev_alloc_skb(size + sizeof(struct ath11k_htc_hdr));
	if (!skb)
		return NULL;

	skb_reserve(skb, sizeof(struct ath11k_htc_hdr));

	/* FW/HTC requires 4-byte aligned streams */
	if (!IS_ALIGNED((unsigned long)skb->data, 4))
		ath11k_warn(ab, "Unaligned HTC tx skb\n");

	return skb;
}

static void ath11k_htc_control_tx_complete(struct ath11k_base *ab,
					   struct sk_buff *skb)
{
	kfree_skb(skb);
}

static struct sk_buff *ath11k_htc_build_tx_ctrl_skb(void *ab)
{
	struct sk_buff *skb;
	struct ath11k_skb_cb *skb_cb;

	skb = dev_alloc_skb(ATH11K_HTC_CONTROL_BUFFER_SIZE);
	if (!skb)
		return NULL;

	skb_reserve(skb, sizeof(struct ath11k_htc_hdr));
	WARN_ON_ONCE(!IS_ALIGNED((unsigned long)skb->data, 4));

	skb_cb = ATH11K_SKB_CB(skb);
	memset(skb_cb, 0, sizeof(*skb_cb));

	return skb;
}

static void ath11k_htc_prepare_tx_skb(struct ath11k_htc_ep *ep,
				      struct sk_buff *skb)
{
	struct ath11k_htc_hdr *hdr;

	hdr = (struct ath11k_htc_hdr *)skb->data;

	memset(hdr, 0, sizeof(*hdr));
	hdr->htc_info = FIELD_PREP(HTC_HDR_ENDPOINTID, ep->eid) |
			FIELD_PREP(HTC_HDR_PAYLOADLEN,
				   (skb->len - sizeof(*hdr)));

	if (ep->tx_credit_flow_enabled)
		hdr->htc_info |= FIELD_PREP(HTC_HDR_FLAGS,
					    ATH11K_HTC_FLAG_NEED_CREDIT_UPDATE);

	spin_lock_bh(&ep->htc->tx_lock);
	hdr->ctrl_info = FIELD_PREP(HTC_HDR_CONTROLBYTES1, ep->seq_no++);
	spin_unlock_bh(&ep->htc->tx_lock);
}

int ath11k_htc_send(struct ath11k_htc *htc,
		    enum ath11k_htc_ep_id eid,
		    struct sk_buff *skb)
{
	struct ath11k_htc_ep *ep = &htc->endpoint[eid];
	struct ath11k_skb_cb *skb_cb = ATH11K_SKB_CB(skb);
	struct device *dev = htc->ab->dev;
	struct ath11k_base *ab = htc->ab;
	int credits = 0;
	int ret;
	bool credit_flow_enabled = (ab->hw_params.credit_flow &&
				    ep->tx_credit_flow_enabled);

	if (eid >= ATH11K_HTC_EP_COUNT) {
		ath11k_warn(ab, "Invalid endpoint id: %d\n", eid);
		return -ENOENT;
	}

	skb_push(skb, sizeof(struct ath11k_htc_hdr));

	if (credit_flow_enabled) {
		credits = DIV_ROUND_UP(skb->len, htc->target_credit_size);
		spin_lock_bh(&htc->tx_lock);
		if (ep->tx_credits < credits) {
			ath11k_dbg(ab, ATH11K_DBG_HTC,
				   "ep %d insufficient credits required %d total %d\n",
				   eid, credits, ep->tx_credits);
			spin_unlock_bh(&htc->tx_lock);
			ret = -EAGAIN;
			goto err_pull;
		}
		ep->tx_credits -= credits;
		ath11k_dbg(ab, ATH11K_DBG_HTC,
			   "ep %d credits consumed %d total %d\n",
			   eid, credits, ep->tx_credits);
		spin_unlock_bh(&htc->tx_lock);
	}

	ath11k_htc_prepare_tx_skb(ep, skb);

	skb_cb->eid = eid;
	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;
	}

	ath11k_dbg(ab, ATH11K_DBG_HTC, "tx skb %p eid %d paddr %pad\n",
		   skb, skb_cb->eid, &skb_cb->paddr);

	ret = ath11k_ce_send(htc->ab, skb, ep->ul_pipe_id, ep->eid);
	if (ret)
		goto err_unmap;

	return 0;

err_unmap:
	dma_unmap_single(dev, skb_cb->paddr, skb->len, DMA_TO_DEVICE);
err_credits:
	if (credit_flow_enabled) {
		spin_lock_bh(&htc->tx_lock);
		ep->tx_credits += credits;
		ath11k_dbg(ab, ATH11K_DBG_HTC,
			   "ep %d credits reverted %d total %d\n",
			   eid, credits, ep->tx_credits);
		spin_unlock_bh(&htc->tx_lock);

		if (ep->ep_ops.ep_tx_credits)
			ep->ep_ops.ep_tx_credits(htc->ab);
	}
err_pull:
	skb_pull(skb, sizeof(struct ath11k_htc_hdr));
	return ret;
}

static void
ath11k_htc_process_credit_report(struct ath11k_htc *htc,
				 const struct ath11k_htc_credit_report *report,
				 int