path: root/drivers/net/ethernet/microsoft/mana/hw_channel.c

// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/* Copyright (c) 2021, Microsoft Corporation. */

#include <net/mana/gdma.h>
#include <net/mana/mana.h>
#include <net/mana/hw_channel.h>
#include <linux/vmalloc.h>

static int mana_hwc_get_msg_index(struct hw_channel_context *hwc, u16 *msg_id)
{
	struct gdma_resource *r = &hwc->inflight_msg_res;
	unsigned long flags;
	u32 index;

	down(&hwc->sema);

	spin_lock_irqsave(&r->lock, flags);

	index = find_first_zero_bit(hwc->inflight_msg_res.map,
				    hwc->inflight_msg_res.size);

	bitmap_set(hwc->inflight_msg_res.map, index, 1);

	spin_unlock_irqrestore(&r->lock, flags);

	*msg_id = index;

	return 0;
}

static void mana_hwc_put_msg_index(struct hw_channel_context *hwc, u16 msg_id)
{
	struct gdma_resource *r = &hwc->inflight_msg_res;
	unsigned long flags;

	spin_lock_irqsave(&r->lock, flags);
	bitmap_clear(hwc->inflight_msg_res.map, msg_id, 1);
	spin_unlock_irqrestore(&r->lock, flags);

	up(&hwc->sema);
}

static int mana_hwc_verify_resp_msg(const struct hwc_caller_ctx *caller_ctx,
				    const struct gdma_resp_hdr *resp_msg,
				    u32 resp_len)
{
	if (resp_len < sizeof(*resp_msg))
		return -EPROTO;

	if (resp_len > caller_ctx->output_buflen)
		return -EPROTO;

	return 0;
}

static int mana_hwc_post_rx_wqe(const struct hwc_wq *hwc_rxq,
				struct hwc_work_request *req)
{
	struct device *dev = hwc_rxq->hwc->dev;
	struct gdma_sge *sge;
	int err;

	sge = &req->sge;
	sge->address = (u64)req->buf_sge_addr;
	sge->mem_key = hwc_rxq->msg_buf->gpa_mkey;
	sge->size = req->buf_len;

	memset(&req->wqe_req, 0, sizeof(struct gdma_wqe_request));
	req->wqe_req.sgl = sge;
	req->wqe_req.num_sge = 1;
	req->wqe_req.client_data_unit = 0;

	err = mana_gd_post_and_ring(hwc_rxq->gdma_wq, &req->wqe_req, NULL);
	if (err)
		dev_err(dev, "Failed to post WQE on HWC RQ: %d\n", err);
	return err;
}

static void mana_hwc_handle_resp(struct hw_channel_context *hwc, u32 resp_len,
				 struct hwc_work_request *rx_req)
{
	const struct gdma_resp_hdr *resp_msg = rx_req->buf_va;
	struct hwc_caller_ctx *ctx;
	int err;

	if (!test_bit(resp_msg->response.hwc_msg_id,
		      hwc->inflight_msg_res.map)) {
		dev_err(hwc->dev, "hwc_rx: invalid msg_id = %u\n",
			resp_msg->response.hwc_msg_id);
		mana_hwc_post_rx_wqe(hwc->rxq, rx_req);
		return;
	}

	ctx = hwc->caller_ctx + resp_msg->response.hwc_msg_id;
	err = mana_hwc_verify_resp_msg(ctx, resp_msg, resp_len);
	if (err)
		goto out;

	ctx->status_code = resp_msg->status;

	memcpy(ctx->output_buf, resp_msg, resp_len);
out:
	ctx->error = err;

	/* Must post rx wqe before complete(), otherwise the next rx may
	 * hit no_wqe error.
	 */
	mana_hwc_post_rx_wqe(hwc->rxq, rx_req);

	complete(&ctx->comp_event);
}

static void mana_hwc_init_event_handler(void *ctx, struct gdma_queue *q_self,
					struct gdma_event *event)
{
	union hwc_init_soc_service_type service_data;
	struct hw_channel_context *hwc = ctx;
	struct gdma_dev *gd = hwc->gdma_dev;
	union hwc_init_type_data type_data;
	union hwc_init_eq_id_db eq_db;
	struct mana_context *ac;
	u32 type, val;
	int ret;

	switch (event->type) {
	case GDMA_EQE_HWC_INIT_EQ_ID_DB:
		eq_db.as_uint32 = event->details[0];
		hwc->cq->gdma_eq->id = eq_db.eq_id;
		gd->doorbell = eq_db.doorbell;
		break;

	case GDMA_EQE_HWC_INIT_DATA:
		type_data.as_uint32 = event->details[0];
		type = type_data.type;
		val = type_data.value