path: root/drivers/net/ethernet/intel/ixgbe/ixgbe_fcoe.c

// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 1999 - 2018 Intel Corporation. */

#include "ixgbe.h"
#include <linux/if_ether.h>
#include <linux/gfp.h>
#include <linux/if_vlan.h>
#include <generated/utsrelease.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <scsi/fc/fc_fs.h>
#include <scsi/fc/fc_fcoe.h>
#include <scsi/libfc.h>
#include <scsi/libfcoe.h>

/**
 * ixgbe_fcoe_clear_ddp - clear the given ddp context
 * @ddp: ptr to the ixgbe_fcoe_ddp
 *
 * Returns : none
 *
 */
static inline void ixgbe_fcoe_clear_ddp(struct ixgbe_fcoe_ddp *ddp)
{
	ddp->len = 0;
	ddp->err = 1;
	ddp->udl = NULL;
	ddp->udp = 0UL;
	ddp->sgl = NULL;
	ddp->sgc = 0;
}

/**
 * ixgbe_fcoe_ddp_put - free the ddp context for a given xid
 * @netdev: the corresponding net_device
 * @xid: the xid that corresponding ddp will be freed
 *
 * This is the implementation of net_device_ops.ndo_fcoe_ddp_done
 * and it is expected to be called by ULD, i.e., FCP layer of libfc
 * to release the corresponding ddp context when the I/O is done.
 *
 * Returns : data length already ddp-ed in bytes
 */
int ixgbe_fcoe_ddp_put(struct net_device *netdev, u16 xid)
{
	int len;
	struct ixgbe_fcoe *fcoe;
	struct ixgbe_adapter *adapter;
	struct ixgbe_fcoe_ddp *ddp;
	struct ixgbe_hw *hw;
	u32 fcbuff;

	if (!netdev)
		return 0;

	if (xid >= netdev->fcoe_ddp_xid)
		return 0;

	adapter = netdev_priv(netdev);
	fcoe = &adapter->fcoe;
	ddp = &fcoe->ddp[xid];
	if (!ddp->udl)
		return 0;

	hw = &adapter->hw;
	len = ddp->len;
	/* if no error then skip ddp context invalidation */
	if (!ddp->err)
		goto skip_ddpinv;

	if (hw->mac.type == ixgbe_mac_X550) {
		/* X550 does not require DDP FCoE lock */

		IXGBE_WRITE_REG(hw, IXGBE_FCDFC(0, xid), 0);
		IXGBE_WRITE_REG(hw, IXGBE_FCDFC(3, xid),
				(xid | IXGBE_FCFLTRW_WE));

		/* program FCBUFF */
		IXGBE_WRITE_REG(hw, IXGBE_FCDDC(2, xid), 0);

		/* program FCDMARW */
		IXGBE_WRITE_REG(hw, IXGBE_FCDDC(3, xid),
				(xid | IXGBE_FCDMARW_WE));

		/* read FCBUFF to check context invalidated */
		IXGBE_WRITE_REG(hw, IXGBE_FCDDC(3, xid),
				(xid | IXGBE_FCDMARW_RE));
		fcbuff = IXGBE_READ_REG(hw, IXGBE_FCDDC(2, xid));
	} else {
		/* other hardware requires DDP FCoE lock */
		spin_lock_bh(&fcoe->lock);
		IXGBE_WRITE_REG(hw, IXGBE_FCFLT, 0);
		IXGBE_WRITE_REG(hw, IXGBE_FCFLTRW,
				(xid | IXGBE_FCFLTRW_WE));
		IXGBE_WRITE_REG(hw, IXGBE_FCBUFF, 0);
		IXGBE_WRITE_REG(hw, IXGBE_FCDMARW,
				(xid | IXGBE_FCDMARW_WE));

		/* guaranteed to be invalidated after 100us */
		IXGBE_WRITE_REG(hw, IXGBE_FCDMARW,
				(xid | IXGBE_FCDMARW_RE));
		fcbuff = IXGBE_READ_REG(hw, IXGBE_FCBUFF);
		spin_unlock_bh(&fcoe->lock);
		}

	if (fcbuff & IXGBE_FCBUFF_VALID)
		usleep_range(100, 150);

skip_ddpinv:
	if (ddp->sgl)
		dma_unmap_sg(&adapter->pdev->dev, ddp->sgl, ddp->sgc,
			     DMA_FROM_DEVICE);
	if (ddp->pool) {
		dma_pool_free(ddp->pool, ddp->udl, ddp->udp);
		ddp->pool = NULL;
	}

	ixgbe_fcoe_clear_ddp(ddp);

	return len;
}

/**
 * ixgbe_fcoe_ddp_setup - called to set up ddp context
 * @netdev: the corresponding net_device
 * @xid: the exchange id requesting ddp
 * @sgl: the scatter-gather list for this request
 * @sgc: the number of scatter-gather items
 * @target_mode: 1 to setup target mode, 0 to setup initiator mode
 *
 * Returns : 1 for success and 0 for no ddp
 */
static int ixgbe_fcoe_ddp_setup(struct net_device *netdev, u16 xid,
				struct scatterlist *sgl, unsigned int sgc,
				int target_mode)
{
	struct ixgbe_adapter *adapter;
	struct ixgbe_hw *hw;
	struct ixgbe_fcoe *fcoe;
	struct ixgbe_fcoe_ddp *ddp;
	struct ixgbe_fcoe_ddp_pool *ddp_pool;
	struct scatterlist *sg;
	unsigned int i, j, dmacount;
	unsigned int len;
	static const unsigned int bufflen = IXGBE_FCBUFF_MIN;
	unsigned int firstoff = 0;
	unsigned int lastsize;
	unsigned int thisoff = 0;
	unsigned int thislen = 0;
	u32 fcbuff, fcdmarw, fcfltrw, fcrxctl;
	dma_addr_t addr = 0;

	if (!netdev || !sgl)
		return 0;

	adapter = netdev_priv(netdev);
	if (xid >= netdev->fcoe_ddp_xid) {
		e_warn(drv, "xid=0x%x out-of-range\n", xid);
		return 0;
	}

	/* no DDP if we are already down or resetting */
	if (test_bit(__IXGBE_DOWN, &adapter->state) ||
	    test_bit(__IXGBE_RESETTING, &adapter->state))
		return 0;

	fcoe = &adapter->fcoe;
	ddp = &fcoe->ddp[xid];
	if (ddp->sgl) {
		e_err(drv, "xid 0x%x w/ non-null sgl=%p nents=%d\n",
		      xid, ddp->sgl, ddp-><