/****************************************************************************
 * Driver for Solarflare Solarstorm network controllers and boards
 * Copyright 2010-2011 Solarflare Communications Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation, incorporated herein by reference.
 */
#include <linux/pci.h>
#include <linux/module.h>
#include "net_driver.h"
#include "efx.h"
#include "nic.h"
#include "io.h"
#include "mcdi.h"
#include "filter.h"
#include "mcdi_pcol.h"
#include "regs.h"
#include "vfdi.h"

/* Number of longs required to track all the VIs in a VF */
#define VI_MASK_LENGTH BITS_TO_LONGS(1 << EFX_VI_SCALE_MAX)

/* Maximum number of RX queues supported */
#define VF_MAX_RX_QUEUES 63

/**
 * enum efx_vf_tx_filter_mode - TX MAC filtering behaviour
 * @VF_TX_FILTER_OFF: Disabled
 * @VF_TX_FILTER_AUTO: Enabled if MAC address assigned to VF and only
 *      2 TX queues allowed per VF.
 * @VF_TX_FILTER_ON: Enabled
 */
enum efx_vf_tx_filter_mode {
        VF_TX_FILTER_OFF,
        VF_TX_FILTER_AUTO,
        VF_TX_FILTER_ON,
};

/**
 * struct efx_vf - Back-end resource and protocol state for a PCI VF
 * @efx: The Efx NIC owning this VF
 * @pci_rid: The PCI requester ID for this VF
 * @pci_name: The PCI name (formatted address) of this VF
 * @index: Index of VF within its port and PF.
 * @req: VFDI incoming request work item. Incoming USR_EV events are received
 *      by the NAPI handler, but must be handled by executing MCDI requests
 *      inside a work item.
 * @req_addr: VFDI incoming request DMA address (in VF's PCI address space).
 * @req_type: Expected next incoming (from VF) %VFDI_EV_TYPE member.
 * @req_seqno: Expected next incoming (from VF) %VFDI_EV_SEQ member.
 * @msg_seqno: Next %VFDI_EV_SEQ member to reply to VF. Protected by
 *      @status_lock
 * @busy: VFDI request queued to be processed or being processed. Receiving
 *      a VFDI request when @busy is set is an error condition.
 * @buf: Incoming VFDI requests are DMA from the VF into this buffer.
 * @buftbl_base: Buffer table entries for this VF start at this index.
 * @rx_filtering: Receive filtering has been requested by the VF driver.
 * @rx_filter_flags: The flags sent in the %VFDI_OP_INSERT_FILTER request.
 * @rx_filter_qid: VF relative qid for RX filter requested by VF.
 * @rx_filter_id: Receive MAC filter ID. Only one filter per VF is supported.
 * @tx_filter_mode: Transmit MAC filtering mode.
 * @tx_filter_id: Transmit MAC filter ID.
 * @addr: The MAC address and outer vlan tag of the VF.
 * @status_addr: VF DMA address of page for &struct vfdi_status updates.
 * @status_lock: Mutex protecting @msg_seqno, @status_addr, @addr,
 *      @peer_page_addrs and @peer_page_count from simultaneous
 *      updates by the VM and consumption by
 *      efx_sriov_update_vf_addr()
 * @peer_page_addrs: Pointer to an array of guest pages for local addresses.
 * @peer_page_count: Number of entries in @peer_page_count.
 * @evq0_addrs: Array of guest pages backing evq0.
 * @evq0_count: Number of entries in @evq0_addrs.
 * @flush_waitq: wait queue used by %VFDI_OP_FINI_ALL_QUEUES handler
 *      to wait for flush completions.
 * @txq_lock: Mutex for TX queue allocation.
 * @txq_mask: Mask of initialized transmit queues.
 * @txq_count: Number of initialized transmit queues.
 * @rxq_mask: Mask of initialized receive queues.
 * @rxq_count: Number of initialized receive queues.
 * @rxq_retry_mask: Mask or receive queues that need to be flushed again
 *      due to flush failure.
 * @rxq_retry_count: Number of receive queues in @rxq_retry_mask.
 * @reset_work: Work item to schedule a VF reset.
 */
struct efx_vf {
        struct efx_nic *efx;
        unsigned int pci_rid;
        char pci_name[13]; /* dddd:bb:dd.f */
        unsigned int index;
        struct work_struct req;
        u64 req_addr;
        int req_type;
        unsigned req_seqno;
        unsigned msg_seqno;
        bool busy;
        struct efx_buffer buf;
        unsigned buftbl_base;
        bool rx_filtering;
        enum efx_filter_flags rx_filter_flags;
        unsigned rx_filter_qid;
        int rx_filter_id;
        enum efx_vf_tx_filter_mode tx_filter_mode;
        int tx_filter_id;
        struct vfdi_endpoint addr;
        u64 status_addr;
        struct mutex status_lock;
        u64 *peer_page_addrs;
        unsigned peer_page_count;
        u64 evq0_addrs[EFX_MAX_VF_EVQ_SIZE * sizeof(efx_qword_t) /
                       EFX_BUF_SIZE];
        unsigned evq0_count;
        wait_queue_head_t flush_waitq;
        struct mutex txq_lock;
        unsigned long txq_mask[VI_MASK_LENGTH];
        unsigned txq_count;
        unsigned long rxq_mask[VI_MASK_LENGTH];
        unsigned rxq_count;
        unsigned long rxq_retry_mask[VI_MASK_LENGTH];
        atomic_t rxq_retry_count;
        struct work_struct reset_work;
};

struct efx_memcpy_req {
        unsigned int from_rid;
        void *from_buf;
        u64 from_addr;
        unsigned int to_rid;
        u64 to_addr;
        unsigned length;
};

/**
 * struct efx_local_addr - A MAC address on the vswitch without a VF.
 *
 * Siena does not have a switch, so VFs can't transmit data to each
 * other. Instead the VFs must be made aware of the local addresses
 * on the vswitch, so that they can arrange for an alternative
 * software datapath to be used.
 *
 * @link: List head for insertion into efx->local_addr_list.
 * @addr: Ethernet address
 */
struct efx_local_addr {
        struct list_head link;
        u8 addr[ETH_ALEN];
};

/**
 * struct efx_endpoint_page - Page of vfdi_endpoint structures
 *
 * @link: List head for insertion into efx->local_page_list.
 * @ptr: Pointer to page.
 * @addr: DMA address of page.
 */
struct efx_endpoint_page {
        struct list_head link;
        void *ptr;
        dma_addr_t addr;
};

/* Buffer table entries are reserved txq0,rxq0,evq0,txq1,rxq1,evq1 */
#define EFX_BUFTBL_TXQ_BASE(_vf, _qid)                                  \
        ((_vf)->buftbl_base + EFX_VF_BUFTBL_PER_VI * (_qid))
#define EFX_BUFTBL_RXQ_BASE(_vf, _qid)                                  \
        (EFX_BUFTBL_TXQ_BASE(_vf, _qid) +                               \
         (EFX_MAX_DMAQ_SIZE * sizeof(efx_qword_t) / EFX_BUF_SIZE))
#define EFX_BUFTBL_EVQ_BASE(_vf, _qid)                                  \
        (EFX_BUFTBL_TXQ_BASE(_vf, _qid) +                               \
         (2 * EFX_MAX_DMAQ_SIZE * sizeof(efx_qword_t) / EFX_BUF_SIZE))

#define EFX_FIELD_MASK(_field)                  \
        ((1 << _field ## _WIDTH) - 1)

/* VFs can only use this many transmit channels */
static unsigned int vf_max_tx_channels = 2;
module_param(vf_max_tx_channels, uint, 0444);
MODULE_PARM_DESC(vf_max_tx_channels,
                 "Limit the number of TX channels VFs can use");

static int max_vfs = -1;
module_param(max_vfs, int, 0444);
MODULE_PARM_DESC(max_vfs,
                 "Reduce the number of VFs initialized by the driver");

/* Workqueue used by VFDI communication.  We can't use the global
 * workqueue because it may be running the VF driver's probe()
 * routine, which will be blocked there waiting for a VFDI response.
 */
static struct workqueue_struct *vfdi_workqueue;

static unsigned abs_index(struct efx_vf *vf, unsigned index)
{
        return EFX_VI_BASE + vf->index * efx_vf_size(vf->efx) + index;
}

static int efx_sriov_cmd(struct efx_nic *efx, bool enable,
                         unsigned *vi_scale_out, unsigned *vf_total_out)
{
        u8 inbuf[MC_CMD_SRIOV_IN_LEN];
        u8 outbuf[MC_CMD_SRIOV_OUT_LEN];
        unsigned vi_scale, vf_total;
        size_t outlen;
        int rc;

        MCDI_SET_DWORD(inbuf, SRIOV_IN_ENABLE, enable ? 1 : 0);
        MCDI_SET_DWORD(inbuf, SRIOV_IN_VI_BASE, EFX_VI_BASE);
        MCDI_SET_DWORD(inbuf, SRIOV_IN_VF_COUNT, efx->vf_count);

        rc = efx_mcdi_rpc(efx, MC_CMD_SRIOV, inbuf, MC_CMD_SRIOV_IN_LEN,
                          outbuf, MC_CMD_SRIOV_OUT_LEN, &outlen);
        if (rc)
                return rc;
        if (outlen < MC_CMD_SRIOV_OUT_LEN)
                return -EIO;

        vf_total = MCDI_DWORD(outbuf, SRIOV_OUT_VF_TOTAL);
        vi_scale = MCDI_DWORD(outbuf, SRIOV_OUT_VI_SCALE);
        if (vi_scale > EFX_VI_SCALE_MAX)
                return -EOPNOTSUPP;

        if (vi_scale_out)
                *vi_scale_out = vi_scale;
        if (vf_total_out)
                *vf_total_out = vf_total;

        return 0;
}

static void efx_sriov_usrev(struct efx_nic *efx, bool enabled)
{
        efx_oword_t reg;

        EFX_POPULATE_OWORD_2(reg,
                             FRF_CZ_USREV_DIS, enabled ? 0 : 1,
                             FRF_CZ_DFLT_EVQ, efx->vfdi_channel->channel);
        efx_writeo(efx, &reg, FR_CZ_USR_EV_CFG);
}

static int efx_sriov_memcpy(struct efx_nic *efx, struct efx_memcpy_req *req,
                            unsigned int count)
{
        u8 *inbuf, *record;
        unsigned int used;
        u32 from_rid, from_hi, from_lo;
        int rc;

        mb();   /* Finish writing source/reading dest before DMA starts */

        used = MC_CMD_MEMCPY_IN_LEN(count);
        if (WARN_ON(used > MCDI_CTL_SDU_LEN_MAX))
                return -ENOBUFS;

        /* Allocate room for the largest request */
        inbuf = kzalloc(MCDI_CTL_SDU_LEN_MAX, GFP_KERNEL);
        if (inbuf == NULL)
                return -ENOMEM;

        record = inbuf;
        MCDI_SET_DWORD(record, MEMCPY_IN_RECORD, count);
        while (count-- > 0) {
                MCDI_SET_DWORD(record, MEMCPY_RECORD_TYPEDEF_TO_RID,
                               req->to_rid);
                MCDI_SET_DWORD(record, MEMCPY_RECORD_TYPEDEF_TO_ADDR_LO,
                               (u32)req->to_addr);
                MCDI_SET_DWORD(record, MEMCPY_RECORD_TYPEDEF_TO_ADDR_HI,
                               (u32)(req->to_addr >> 32));
                if (req->from_buf == NULL) {
                        from_rid = req->from_rid;
                        from_lo = (u32)req->from_addr;
                        from_hi = (u32)(req->from_addr >> 32);
                } else {
                        if (WARN_ON(used + req->length > MCDI_CTL_SDU_LEN_MAX)) {
                                rc = -ENOBUFS;
                                goto out;
                        }

                        from_rid = MC_CMD_MEMCPY_RECORD_TYPEDEF_RID_INLINE;
                        from_lo = used;
                        from_hi = 0;
                        memcpy(inbuf + used, req->from_buf, req->length);
                        used += req->length;
                }

                MCDI_SET_DWORD(record, MEMCPY_RECORD_TYPEDEF_FROM_RID, from_rid);
                MCDI_SET_DWORD(record, MEMCPY_RECORD_TYPEDEF_FROM_ADDR_LO,
                               from_lo);
                MCDI_SET_DWORD(record, MEMCPY_RECORD_TYPEDEF_FROM_ADDR_HI,
                               from_hi);
                MCDI_SET_DWORD(record, MEMCPY_RECORD_TYPEDEF_LENGTH,
                               req->length);

                ++req;
                record += MC_CMD_MEMCPY_IN_RECORD_LEN;
        }

        rc = efx_mcdi_rpc(efx, MC_CMD_MEMCPY, inbuf, used, NULL, 0, NULL);
out:
        kfree(inbuf);

        mb();   /* Don't write source/read dest before DMA is complete */

        return rc;
}

/* The TX filter is entirely controlled by this driver, and is modified
 * underneath the feet of the VF
 */
static void efx_sriov_reset_tx_filter(struct efx_vf *vf)
{
        struct efx_nic *efx = vf->efx;
        struct efx_filter_spec filter;
        u16 vlan;
        int rc;

        if (vf->tx_filter_id != -1) {
                efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
                                          vf->tx_filter_id);
                netif_dbg(efx, hw, efx->net_dev, "Removed vf %s tx filter %d\n",
                          vf->pci_name, vf->tx_filter_id);
                vf->tx_filter_id = -1;
        }

        if (is_zero_ether_addr(vf->addr.mac_addr))
                return;

        /* Turn on TX filtering automatically if not explicitly
         * enabled or disabled.
         */
        if (vf->tx_filter_mode == VF_TX_FILTER_AUTO && vf_max_tx_channels <= 2)
                vf->tx_filter_mode = VF_TX_FILTER_ON;

        vlan = ntohs(vf->addr.tci) & VLAN_VID_MASK;
        efx_filter_init_tx(&filter, abs_index(vf, 0));
        rc = efx_filter_set_eth_local(&filter,
                                      vlan ? vlan : EFX_FILTER_VID_UNSPEC,
                                      vf->addr.mac_addr);
        BUG_ON(rc);

        rc = efx_filter_insert_filter(efx, &filter, true);
        if (rc < 0) {
                netif_warn(efx, hw, efx->net_dev,
                           "Unable to migrate tx filter for vf %s\n",
                           vf->pci_name);
        } else {
                netif_dbg(efx, hw, efx->net_dev, "Inserted vf %s tx filter %d\n",
                          vf->pci_name, rc);
                vf->tx_filter_id = rc;
        }
}

/* The RX filter is managed here on behalf of the VF driver */
static void efx_sriov_reset_rx_filter(struct efx_vf *vf)
{
        struct efx_nic *efx = vf->efx;
        struct efx_filter_spec filter;
        u16 vlan;
        int rc;

        if (vf->rx_filter_id != -1) {
                efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
                                          vf->rx_filter_id);
                netif_dbg(efx, hw, efx->net_dev, "Removed vf %s rx filter %d\n",
                          vf->pci_name, vf->rx_filter_id);
                vf->rx_filter_id = -1;
        }

        if (!vf->rx_filtering || is_zero_ether_addr(vf->addr.mac_addr))
                return;

        vlan = ntohs(vf->addr.tci) & VLAN_VID_MASK;
        efx_filter_init_rx(&filter, EFX_FILTER_PRI_REQUIRED,
                           vf->rx_filter_flags,
                           abs_index(vf, vf->rx_filter_qid));
        rc = efx_filter_set_eth_local(&filter,
                                      vlan ? vlan : EFX_FILTER_VID_UNSPEC,
                                      vf->addr.mac_addr);
        BUG_ON(rc);

        rc = efx_filter_insert_filter(efx, &filter, true);
        if (rc < 0) {
                netif_warn(efx, hw, efx->net_dev,
                           "Unable to insert rx filter for vf %s\n",
                           vf->pci_name);
        } else {
                netif_dbg(efx, hw, efx->net_dev, "Inserted vf %s rx filter %d\n",
                          vf->pci_name, rc);
                vf->rx_filter_id = rc;
        }
}

static void __efx_sriov_update_vf_addr(struct efx_vf *vf)
{
        efx_sriov_reset_tx_filter(vf);
        efx_sriov_reset_rx_filter(vf);
        queue_work(vfdi_workqueue, &vf->efx->peer_work);
}

/* Push the peer list to this VF. The caller must hold status_lock to interlock
 * with VFDI requests, and they must be serialised against manipulation of
 * local_page_list, either by acquiring local_lock or by running from
 * efx_sriov_peer_work()
 */
static void __efx_sriov_push_vf_status(struct efx_vf *vf)
{
        struct efx_nic *efx = vf->efx;
        struct vfdi_status *status = efx->vfdi_status.addr;
        struct efx_memcpy_req copy[4];
        struct efx_endpoint_page *epp;
        unsigned int pos, count;
        unsigned data_offset;
        efx_qword_t event;

        WARN_ON(!mutex_is_locked(&vf->status_lock));
        WARN_ON(!vf->status_addr);

        status->local = vf->addr;
        status->generation_end = ++status->generation_start;

        memset(copy, '\0', sizeof(copy));
        /* Write generation_start */
        copy[0].from_buf = &status->generation_start;
        copy[0].to_rid = vf->pci_rid;
        copy[0].to_addr = vf->status_addr + offsetof(struct vfdi_status,
                                                     generation_start);
        copy[0].length = sizeof(status->generation_start);
        /* DMA the rest of the structure (excluding the generations). This
         * assumes that the non-generation portion of vfdi_status is in
         * one chunk starting at the version member.
         */
        data_offset = offsetof(struct vfdi_status, version);
        copy[1].from_rid = efx->pci_dev->devfn;
        copy[1].from_addr = efx->vfdi_status.dma_addr + data_offset;
        copy[1].to_rid = vf->pci_rid;
        copy[1].to_addr = vf->status_addr + data_offset;
        copy[1].length =  status->length - data_offset;

        /* Copy the peer pages */
        pos = 2;
        count = 0;
        list_for_each_entry(epp, &efx->local_page_list, link) {
                if (count == vf->peer_page_count) {
                        /* The VF driver will know they need to provide more
                         * pages because peer_addr_count is too large.
                         */
                        break;
                }
                copy[pos].from_buf = NULL;
                copy[pos].from_rid = efx->pci_dev->devfn;
                copy[pos].from_addr = epp->addr;
                copy[pos].to_rid = vf->pci_rid;
                copy[pos].to_addr = vf->peer_page_addrs[count];
                copy[pos].length = EFX_PAGE_SIZE;

                if (++pos == ARRAY_SIZE(copy)) {
                        efx_sriov_memcpy(efx, copy, ARRAY_SIZE(copy));
                        pos = 0;
                }
                ++count;
        }

        /* Write generation_end */
        copy[pos].from_buf = &status->generation_end;
        copy[pos].to_rid = vf->pci_rid;
        copy[pos].to_addr = vf->status_addr + offsetof(struct vfdi_status,
                                                       generation_end);
        copy[pos].length = sizeof(status->generation_end);
        efx_sriov_memcpy(efx, copy, pos + 1);

        /* Notify the guest */
        EFX_POPULATE_QWORD_3(event,
                             FSF_AZ_EV_CODE, FSE_CZ_EV_CODE_USER_EV,
                             VFDI_EV_SEQ, (vf->msg_seqno & 0xff),
                             VFDI_EV_TYPE, VFDI_EV_TYPE_STATUS);
        ++vf->msg_seqno;
        efx_generate_event(efx, EFX_VI_BASE + vf->index * efx_vf_size(efx),
                              &event);
}

static void efx_sriov_bufs(struct efx_nic *efx, unsigned offset,
                           u64 *addr, unsigned count)
{
        efx_qword_t buf;
        unsigned pos;

        for (pos = 0; pos < count; ++pos) {
                EFX_POPULATE_QWORD_3(buf,
                                     FRF_AZ_BUF_ADR_REGION, 0,
                                     FRF_AZ_BUF_ADR_FBUF,
                                     addr ? addr[pos] >> 12 : 0,
                                     FRF_AZ_BUF_OWNER_ID_FBUF, 0);
                efx_sram_writeq(efx, efx->membase + FR_BZ_BUF_FULL_TBL,
                                &buf, offset + pos);
        }
}

static bool bad_vf_index(struct efx_nic *efx, unsigned index)
{
        return index >= efx_vf_size(efx);
}

static bool bad_buf_count(unsigned buf_count, unsigned max_entry_count)
{
        unsigned max_buf_count = max_entry_count *
                sizeof(efx_qword_t) / EFX_BUF_SIZE;

        return ((buf_count & (buf_count - 1)) || buf_count > max_buf_count);
}

/* Check that VI specified by per-port index belongs to a VF.
 * Optionally set VF index and VI index within the VF.
 */
static bool map_vi_index(struct efx_nic *efx, unsigned abs_index,
                         struct efx_vf **vf_out, unsigned *rel_index_out)
{
        unsigned vf_i;

        if (abs_index < EFX_VI_BASE)
                return true;
        vf_i = (abs_index - EFX_VI_BASE) / efx_vf_size(efx);
        if (vf_i >= efx->vf_init_count)
                return true;

        if (vf_out)
                *vf_out = efx->vf + vf_i;
        if (rel_index_out)
                *rel_index_out = abs_index % efx_vf_size(efx);
        return false;
}

static int efx_vfdi_init_evq(struct efx_vf *vf)
{
        struct efx_nic *efx = vf->efx;
        struct vfdi_req *req = vf->buf.addr;
        unsigned vf_evq = req->u.init_evq.index;
        unsigned buf_count = req->u.init_evq.buf_count;
        unsigned abs_evq = abs_index(vf, vf_evq);
        unsigned buftbl = EFX_BUFTBL_EVQ_BASE(vf, vf_evq);
        efx_oword_t reg;

        if (bad_vf_index(efx, vf_evq) ||
            bad_buf_count(buf_count, EFX_MAX_VF_EVQ_SIZE)) {
                if (net_ratelimit())
                        netif_err(efx, hw, efx->net_dev,
                                  "ERROR: Invalid INIT_EVQ from %s: evq %d bufs %d\n",
                                  vf->pci_name, vf_evq, buf_count);
                return VFDI_RC_EINVAL;
        }

        efx_sriov_bufs(efx, buftbl, req->u.init_evq.addr, buf_count);

        EFX_POPULATE_OWORD_3(reg,
                             FRF_CZ_TIMER_Q_EN, 1,
                             FRF_CZ_HOST_NOTIFY_MODE, 0,
                             FRF_CZ_TIMER_MODE, FFE_CZ_TIMER_MODE_DIS);
        efx_writeo_table(efx, &reg, FR_BZ_TIMER_TBL, abs_evq);
        EFX_POPULATE_OWORD_3(reg,
                             FRF_AZ_EVQ_EN, 1,
                             FRF_AZ_EVQ_SIZE, __ffs(buf_count),
                             FRF_AZ_EVQ_BUF_BASE_ID, buftbl);
        efx_writeo_table(efx, &reg, FR_BZ_EVQ_PTR_TBL, abs_evq);

        if (vf_evq == 0) {
                memcpy(vf->evq0_addrs, req->u.init_evq.addr,
                       buf_count * sizeof(u64));
                vf->evq0_count = buf_count;
        }

        return VFDI_RC_SUCCESS;
}

static int efx_vfdi_init_rxq(struct efx_vf *vf)
{
        struct efx_nic *efx = vf->efx;
        struct vfdi_req *req = vf->buf.addr;
        unsigned vf_rxq = req->u.init_rxq.index;
        unsigned vf_evq = req->u.init_rxq.evq;
        unsigned buf_count = req->u.init_rxq.buf_count;
        unsigned buftbl = EFX_BUFTBL_RXQ_BASE(vf, vf_rxq);
        unsigned label;
        efx_oword_t reg;

        if (bad_vf_index(efx, vf_evq) || bad_vf_index(efx, vf_rxq) ||
            vf_rxq >= VF_MAX_RX_QUEUES ||
            bad_buf_count(buf_count, EFX_MAX_DMAQ_SIZE)) {
                if (net_ratelimit())
                        netif_err(efx, hw, efx->net_dev,
                                  "ERROR: Invalid INIT_RXQ from %s: rxq %d evq %d "
                                  "buf_count %d\n", vf->pci_name, vf_rxq,
                                  vf_evq, buf_count);
                return VFDI_RC_EINVAL;
        }
        if (__test_and_set_bit(req->u.init_rxq.index, vf->rxq_mask))
                ++vf->rxq_count;
        efx_sriov_bufs(efx, buftbl, req->u.init_rxq.addr, buf_count);

        label = req->u.init_rxq.label & EFX_FIELD_MASK(FRF_AZ_RX_DESCQ_LABEL);
        EFX_POPULATE_OWORD_6(reg,
                             FRF_AZ_RX_DESCQ_BUF_BASE_ID, buftbl,
                             FRF_AZ_RX_DESCQ_EVQ_ID, abs_index(vf, vf_evq),
                             FRF_AZ_RX_DESCQ_LABEL, label,
                             FRF_AZ_RX_DESCQ_SIZE, __ffs(buf_count),
                             FRF_AZ_RX_DESCQ_JUMBO,
                             !!(req->u.init_rxq.flags &
                                VFDI_RXQ_FLAG_SCATTER_EN),
                             FRF_AZ_RX_DESCQ_EN, 1);
        efx_writeo_table(efx, &reg, FR_BZ_RX_DESC_PTR_TBL,
                         abs_index(vf, vf_rxq));

        return VFDI_RC_SUCCESS;
}

static int efx_vfdi_init_txq(struct efx_vf *vf)
{
        struct efx_nic *efx = vf->efx;
        struct vfdi_req *req = vf->buf.addr;
        unsigned vf_txq = req->u.init_txq.index;
        unsigned vf_evq = req->u.init_txq.evq;
        unsigned buf_count = req->u.init_txq.buf_count;
        unsigned buftbl = EFX_BUFTBL_TXQ_BASE(vf, vf_txq);
        unsigned label, eth_filt_en;
        efx_oword_t reg;

        if (bad_vf_index(efx, vf_evq) || bad_vf_index(efx, vf_txq) ||
            vf_txq >= vf_max_tx_channels ||
            bad_buf_count(buf_count, EFX_MAX_DMAQ_SIZE)) {
                if (net_ratelimit())
                        netif_err(efx, hw, efx->net_dev,
                                  "ERROR: Invalid INIT_TXQ from %s: txq %d evq %d "
                                  "buf_count %d\n", vf->pci_name, vf_txq,
                                  vf_evq, buf_count);
                return VFDI_RC_EINVAL;
        }

        mutex_lock(&vf->txq_lock);
        if (__test_and_set_bit(req->u.init_txq.index, vf->txq_mask))
                ++vf->txq_count;
        mutex_unlock(&vf->txq_lock);
        efx_sriov_bufs(efx, buftbl, req->u.init_txq.addr, buf_count);

        eth_filt_en = vf->tx_filter_mode == VF_TX_FILTER_ON;

        label = req->u.init_txq.label & EFX_FIELD_MASK(FRF_AZ_TX_DESCQ_LABEL);
        EFX_POPULATE_OWORD_8(reg,
                             FRF_CZ_TX_DPT_Q_MASK_WIDTH, min(efx->vi_scale, 1U),
                             FRF_CZ_TX_DPT_ETH_FILT_EN, eth_filt_en,
                             FRF_AZ_TX_DESCQ_EN, 1,
                             FRF_AZ_TX_DESCQ_BUF_BASE_ID, buftbl,
                             FRF_AZ_TX_DESCQ_EVQ_ID, abs_index(vf, vf_evq),
                             FRF_AZ_TX_DESCQ_LABEL, label,
                             FRF_AZ_TX_DESCQ_SIZE, __ffs(buf_count),
                             FRF_BZ_TX_NON_IP_DROP_DIS, 1);
        efx_writeo_table(efx, &reg, FR_BZ_TX_DESC_PTR_TBL,
                         abs_index(vf, vf_txq));

        return VFDI_RC_SUCCESS;
}

/* Returns true when efx_vfdi_fini_all_queues should wake */
static bool efx_vfdi_flush_wake(struct efx_vf *vf)
{
        /* Ensure that all updates are visible to efx_vfdi_fini_all_queues() */
        smp_mb();

        return (!vf->txq_count && !vf->rxq_count) ||
                atomic_read(&vf->rxq_retry_count);
}

static void efx_vfdi_flush_clear(struct efx_vf *vf)
{
        memset(vf->txq_mask, 0, sizeof(vf->txq_mask));
        vf->txq_count = 0;
        memset(vf->rxq_mask, 0, sizeof(vf->rxq_mask));
        vf->rxq_count = 0;
        memset(vf->rxq_retry_mask, 0, sizeof(vf->rxq_retry_mask));
        atomic_set(&vf->rxq_retry_count, 0);
}

static int efx_vfdi_fini_all_queues(struct efx_vf *vf)
{
        struct efx_nic *efx = vf->efx;
        efx_oword_t reg;
        unsigned count = efx_vf_size(efx);
        unsigned vf_offset = EFX_VI_BASE + vf->index * efx_vf_size(efx);
        unsigned timeout = HZ;
        unsigned index, rxqs_count;
        __le32 *rxqs;
        int rc;

        BUILD_BUG_ON(VF_MAX_RX_QUEUES >
                     MC_CMD_FLUSH_RX_QUEUES_IN_QID_OFST_MAXNUM);

        rxqs = kmalloc(count * sizeof(*rxqs), GFP_KERNEL);
        if (rxqs == NULL)
                return VFDI_RC_ENOMEM;

        rtnl_lock();
        siena_prepare_flush(efx);
        rtnl_unlock();

        /* Flush all the initialized queues */
        rxqs_count = 0;
        for (index = 0; index < count; ++index) {
                if (test_bit(index, vf->txq_mask)) {
                        EFX_POPULATE_OWORD_2(reg,
                                             FRF_AZ_TX_FLUSH_DESCQ_CMD, 1,
                                             FRF_AZ_TX_FLUSH_DESCQ,
                                             vf_offset + index);
                        efx_writeo(efx, &reg, FR_AZ_TX_FLUSH_DESCQ);
                }
                if (test_bit(index, vf->rxq_mask))
                        rxqs[rxqs_count++] = cpu_to_le32(vf_offset + index);
        }

        atomic_set(&vf->rxq_retry_count, 0);
        while (timeout && (vf->rxq_count || vf->txq_count)) {
                rc = efx_mcdi_rpc(efx, MC_CMD_FLUSH_RX_QUEUES, (u8 *)rxqs,
                                  rxqs_count * sizeof(*rxqs), NULL, 0, NULL);
                WARN_ON(rc < 0);

                timeout = wait_event_timeout(vf->flush_waitq,
                                             efx_vfdi_flush_wake(vf),
                                             timeout);
                rxqs_count = 0;
                for (index = 0; index < count; ++index) {
                        if (test_and_clear_bit(index, vf->rxq_retry_mask)) {
                                atomic_dec(&vf->rxq_retry_count);
                                rxqs[rxqs_count++] =
                                        cpu_to_le32(vf_offset + index);
                        }
                }
        }

        rtnl_lock();
        siena_finish_flush(efx);
        rtnl_unlock();

        /* Irrespective of success/failure, fini the queues */
        EFX_ZERO_OWORD(reg);
        for (index = 0; index < count; ++index) {
                efx_writeo_table(efx, &reg, FR_BZ_RX_DESC_PTR_TBL,
                                 vf_offset + index);
                efx_writeo_table(efx, &reg, FR_BZ_TX_DESC_PTR_TBL,
                                 vf_offset + index);
                efx_writeo_table(efx, &reg, FR_BZ_EVQ_PTR_TBL,
                                 vf_offset + index);
                efx_writeo_table(efx, &reg, FR_BZ_TIMER_TBL,
                                 vf_offset + index);
        }
        efx_sriov_bufs(efx, vf->buftbl_base, NULL,
                       EFX_VF_BUFTBL_PER_VI * efx_vf_size(efx));
        kfree(rxqs);
        efx_vfdi_flush_clear(vf);

        vf->evq0_count = 0;

        return timeout ? 0 : VFDI_RC_ETIMEDOUT;
}

static int efx_vfdi_insert_filter(struct efx_vf *vf)
{
        struct efx_nic *efx = vf->efx;
        struct vfdi_req *req = vf->buf.addr;
        unsigned vf_rxq = req->u.mac_filter.rxq;
        unsigned flags;

        if (bad_vf_index(efx, vf_rxq) || vf->rx_filtering) {
                if (net_ratelimit())
                        netif_err(efx, hw, efx->net_dev,
                                  "ERROR: Invalid INSERT_FILTER from %s: rxq %d "
                                  "flags 0x%x\n", vf->pci_name, vf_rxq,
                                  req->u.mac_filter.flags);
                return VFDI_RC_EINVAL;
        }

        flags = 0;
        if (req->u.mac_filter.flags & VFDI_MAC_FILTER_FLAG_RSS)
                flags |= EFX_FILTER_FLAG_RX_RSS;
        if (req->u.mac_filter.flags & VFDI_MAC_FILTER_FLAG_SCATTER)
                flags |= EFX_FILTER_FLAG_RX_SCATTER;
        vf->rx_filter_flags = flags;
        vf->rx_filter_qid = vf_rxq;
        vf->rx_filtering = true;

        efx_sriov_reset_rx_filter(vf);
        queue_work(vfdi_workqueue, &efx->peer_work);

        return VFDI_RC_SUCCESS;
}

static int efx_vfdi_remove_all_filters(struct efx_vf *vf)
{
        vf->rx_filtering = false;
        efx_sriov_reset_rx_filter(vf);
        queue_work(vfdi_workqueue, &vf->efx->peer_work);

        return VFDI_RC_SUCCESS;
}

static int efx_vfdi_set_status_page(struct efx_vf *vf)
{
        struct efx_nic *efx = vf->efx;
        struct vfdi_req *req = vf->buf.addr;
        u64 page_count = req->u.set_status_page.peer_page_count;
        u64 max_page_count =
                (EFX_PAGE_SIZE -
                 offsetof(struct vfdi_req, u.set_status_page.peer_page_addr[0]))
                / sizeof(req->u.set_status_page.peer_page_addr[0]);

        if (!req->u.set_status_page.dma_addr || page_count > max_page_count) {
                if (net_ratelimit())
                        netif_err(efx, hw, efx->net_dev,
                                  "ERROR: Invalid SET_STATUS_PAGE from %s\n",
                                  vf->pci_name);
                return VFDI_RC_EINVAL;
        }

        mutex_lock(&efx->local_lock);
        mutex_lock(&vf->status_lock);
        vf->status_addr = req->u.set_status_page.dma_addr;

        kfree(vf->peer_page_addrs);
        vf->peer_page_addrs = NULL;
        vf->peer_page_count = 0;

        if (page_count) {
                vf->peer_page_addrs = kcalloc(page_count, sizeof(u64),
                                              GFP_KERNEL);
                if (vf->peer_page_addrs) {
                        memcpy(vf->peer_page_addrs,
                               req->u.set_status_page.peer_page_addr,
                               page_count * sizeof(u64));
                        vf->peer_page_count = page_count;
                }
        }

        __efx_sriov_push_vf_status(vf);
        mutex_unlock(&vf->status_lock);
        mutex_unlock(&efx->local_lock);

        return VFDI_RC_SUCCESS;
}

static int efx_vfdi_clear_status_page(struct efx_vf *vf)
{
        mutex_lock(&vf->status_lock);
        vf->status_addr = 0;
        mutex_unlock(&vf->status_lock);

        return VFDI_RC_SUCCESS;
}

typedef int (*efx_vfdi_op_t)(struct efx_vf *vf);

static const efx_vfdi_op_t vfdi_ops[VFDI_OP_LIMIT] = {
        [VFDI_OP_INIT_EVQ] = efx_vfdi_init_evq,
        [VFDI_OP_INIT_TXQ] = efx_vfdi_init_txq,
        [VFDI_OP_INIT_RXQ] = efx_vfdi_init_rxq,
        [VFDI_OP_FINI_ALL_QUEUES] = efx_vfdi_fini_all_queues,
        [VFDI_OP_INSERT_FILTER] = efx_vfdi_insert_filter,
        [VFDI_OP_REMOVE_ALL_FILTERS] = efx_vfdi_remove_all_filters,
        [VFDI_OP_SET_STATUS_PAGE] = efx_vfdi_set_status_page,
        [VFDI_OP_CLEAR_STATUS_PAGE] = efx_vfdi_clear_status_page,
};

static void efx_sriov_vfdi(struct work_struct *work)
{
        struct efx_vf *vf = container_of(work, struct efx_vf, req);
        struct efx_nic *efx = vf->efx;
        struct vfdi_req *req = vf->buf.addr;
        struct efx_memcpy_req copy[2];
        int rc;

        /* Copy this page into the local address space */
        memset(copy, '\0', sizeof(copy));
        copy[0].from_rid = vf->pci_rid;
        copy[0].from_addr = vf->req_addr;
        copy[0].to_rid = efx->pci_dev->devfn;
        copy[0].to_addr = vf->buf.dma_addr;
        copy[0].length = EFX_PAGE_SIZE;
        rc = efx_sriov_memcpy(efx, copy, 1);
        if (rc) {
                /* If we can't get the request, we can't reply to the caller */
                if (net_ratelimit())
                        netif_err(efx, hw, efx->net_dev,
                                  "ERROR: Unable to fetch VFDI request from %s rc %d\n",
                                  vf->pci_name, -rc);
                vf->busy = false;
                return;
        }

        if (req->op < VFDI_OP_LIMIT && vfdi_ops[req->op] != NULL) {
                rc = vfdi_ops[req->op](vf);
                if (rc == 0) {
                        netif_dbg(efx, hw, efx->net_dev,
                                  "vfdi request %d from %s ok\n",
                                  req->op, vf->pci_name);
                }
        } else {
                netif_dbg(efx, hw, efx->net_dev,
                          "ERROR: Unrecognised request %d from VF %s addr "
                          "%llx\n", req->op, vf->pci_name,
                          (unsigned long long)vf->req_addr);
                rc = VFDI_RC_EOPNOTSUPP;
        }

        /* Allow subsequent VF requests */
        vf->busy = false;
        smp_wmb();

        /* Respond to the request */
        req->rc = rc;
        req->op = VFDI_OP_RESPONSE;

        memset(copy, '\0', sizeof(copy));
        copy[0].from_buf = &req->rc;
        copy[0].to_rid = vf->pci_rid;
        copy[0].to_addr = vf->req_addr + offsetof(struct vfdi_req, rc);
        copy[0].length = sizeof(req->rc);
        copy[1].from_buf = &req->op;
        copy[1].to_rid = vf->pci_rid;
        copy[1].to_addr = vf->req_addr + offsetof(struct vfdi_req, op);
        copy[1].length = sizeof(req->op);

        (void) efx_sriov_memcpy(efx, copy, ARRAY_SIZE(copy));
}



/* After a reset the event queues inside the guests no longer exist. Fill the
 * event ring in guest memory with VFDI reset events, then (re-initialise) the
 * event queue to raise an interrupt. The guest driver will then recover.
 */
static void efx_sriov_reset_vf(struct efx_vf *vf, struct efx_buffer *buffer)
{
        struct efx_nic *efx = vf->efx;
        struct efx_memcpy_req copy_req[4];
        efx_qword_t event;
        unsigned int pos, count, k, buftbl, abs_evq;
        efx_oword_t reg;
        efx_dword_t ptr;
        int rc;

        BUG_ON(buffer->len != EFX_PAGE_SIZE);

        if (!vf->evq0_count)
                return;
        BUG_ON(vf->evq0_count & (vf->evq0_count - 1));

        mutex_lock(&vf->status_lock);
        EFX_POPULATE_QWORD_3(event,
                             FSF_AZ_EV_CODE, FSE_CZ_EV_CODE_USER_EV,
                             VFDI_EV_SEQ, vf->msg_seqno,
                             VFDI_EV_TYPE, VFDI_EV_TYPE_RESET);
        vf->msg_seqno++;
        for (pos = 0; pos < EFX_PAGE_SIZE; pos += sizeof(event))
                memcpy(buffer->addr + pos, &event, sizeof(event));

        for (pos = 0; pos < vf->evq0_count; pos += count) {
                count = min_t(unsigned, vf->evq0_count - pos,
                              ARRAY_SIZE(copy_req));
                for (k = 0; k < count; k++) {
                        copy_req[k].from_buf = NULL;
                        copy_req[k].from_rid = efx->pci_dev->devfn;
                        copy_req[k].from_addr = buffer->dma_addr;
                        copy_req[k].to_rid = vf->pci_rid;
                        copy_req[k].to_addr = vf->evq0_addrs[pos + k];
                        copy_req[k].length = EFX_PAGE_SIZE;
                }
                rc = efx_sriov_memcpy(efx, copy_req, count);
                if (rc) {
                        if (net_ratelimit())
                                netif_err(efx, hw, efx->net_dev,
                                          "ERROR: Unable to notify %s of reset"
                                          ": %d\n", vf->pci_name, -rc);
                        break;
                }
        }

        /* Reinitialise, arm and trigger evq0 */
        abs_evq = abs_index(vf, 0);
        buftbl = EFX_BUFTBL_EVQ_BASE(vf, 0);
        efx_sriov_bufs(efx, buftbl, vf->evq0_addrs, vf->evq0_count);

        EFX_POPULATE_OWORD_3(reg,
                             FRF_CZ_TIMER_Q_EN, 1,
                             FRF_CZ_HOST_NOTIFY_MODE, 0,
                             FRF_CZ_TIMER_MODE, FFE_CZ_TIMER_MODE_DIS);
        efx_writeo_table(efx, &reg, FR_BZ_TIMER_TBL, abs_evq);
        EFX_POPULATE_OWORD_3(reg,
                             FRF_AZ_EVQ_EN, 1,
                             FRF_AZ_EVQ_SIZE, __ffs(vf->evq0_count),
                             FRF_AZ_EVQ_BUF_BASE_ID, buftbl);
        efx_writeo_table(efx, &reg, FR_BZ_EVQ_PTR_TBL, abs_evq);
        EFX_POPULATE_DWORD_1(ptr, FRF_AZ_EVQ_RPTR, 0);
        efx_writed(efx, &ptr, FR_BZ_EVQ_RPTR + FR_BZ_EVQ_RPTR_STEP * abs_evq);

        mutex_unlock(&vf->status_lock);
}

static void efx_sriov_reset_vf_work(struct work_struct *work)
{
        struct efx_vf *vf = container_of(work, struct efx_vf, req);
        struct efx_nic *efx = vf->efx;
        struct efx_buffer buf;

        if (!efx_nic_alloc_buffer(efx, &buf, EFX_PAGE_SIZE)) {
                efx_sriov_reset_vf(vf, &buf);
                efx_nic_free_buffer(efx, &buf);
        }
}

static void efx_sriov_handle_no_channel(struct efx_nic *efx)
{
        netif_err(efx, drv, efx->net_dev,
                  "ERROR: IOV requires MSI-X and 1 additional interrupt"
                  "vector. IOV disabled\n");
        efx->vf_count = 0;
}

static int efx_sriov_probe_channel(struct efx_channel *channel)
{
        channel->efx->vfdi_channel = channel;
        return 0;
}

static void
efx_sriov_get_channel_name(struct efx_channel *channel, char *buf, size_t len)
{
        snprintf(buf, len, "%s-iov", channel->efx->name);
}

static const struct efx_channel_type efx_sriov_channel_type = {
        .handle_no_channel      = efx_sriov_handle_no_channel,
        .pre_probe              = efx_sriov_probe_channel,
        .post_remove            = efx_channel_dummy_op_void,
        .get_name               = efx_sriov_get_channel_name,
        /* no copy operation; channel must not be reallocated */
        .keep_eventq            = true,
};

void efx_sriov_probe(struct efx_nic *efx)
{
        unsigned count;

        if (!max_vfs)
                return;

        if (efx_sriov_cmd(efx, false, &efx->vi_scale, &count))
                return;
        if (count > 0 && count > max_vfs)
                count = max_vfs;

        /* efx_nic_dimension_resources() will reduce vf_count as appopriate */
        efx->vf_count = count;

        efx->extra_channel_type[EFX_EXTRA_CHANNEL_IOV] = &efx_sriov_channel_type;
}

/* Copy the list of individual addresses into the vfdi_status.peers
 * array and auxillary pages, protected by %local_lock. Drop that lock
 * and then broadcast the address list to every VF.
 */
static void efx_sriov_peer_work(struct work_struct *data)
{
        struct efx_nic *efx = container_of(data, struct efx_nic, peer_work);
        struct vfdi_status *vfdi_status = efx->vfdi_status.addr;
        struct efx_vf *vf;
        struct efx_local_addr *local_addr;
        struct vfdi_endpoint *peer;
        struct efx_endpoint_page *epp;
        struct list_head pages;
        unsigned int peer_space;
        unsigned int peer_count;
        unsigned int pos;

        mutex_lock(&efx->local_lock);

        /* Move the existing peer pages off %local_page_list */
        INIT_LIST_HEAD(&pages);
        list_splice_tail_init(&efx->local_page_list, &pages);

        /* Populate the VF addresses starting from entry 1 (entry 0 is
         * the PF address)
         */
        peer = vfdi_status->peers + 1;
        peer_space = ARRAY_SIZE(vfdi_status->peers) - 1;
        peer_count = 1;
        for (pos = 0; pos < efx->vf_count; ++pos) {
                vf = efx->vf + pos;

                mutex_lock(&vf->status_lock);
                if (vf->rx_filtering && !is_zero_ether_addr(vf->addr.mac_addr)) {
                        *peer++ = vf->addr;
                        ++peer_count;
                        --peer_space;
                        BUG_ON(peer_space == 0);
                }
                mutex_unlock(&vf->status_lock);
        }

        /* Fill the remaining addresses */
        list_for_each_entry(local_addr, &efx->local_addr_list, link) {
                memcpy(peer->mac_addr, local_addr->addr, ETH_ALEN);
                peer->tci = 0;
                ++peer;
                ++peer_count;
                if (--peer_space == 0) {
                        if (list_empty(&pages)) {
                                epp = kmalloc(sizeof(*epp), GFP_KERNEL);
                                if (!epp)
                                        break;
                                epp->ptr = dma_alloc_coherent(
                                        &efx->pci_dev->dev, EFX_PAGE_SIZE,
                                        &epp->addr, GFP_KERNEL);
                                if (!epp->ptr) {
                                        kfree(epp);
                                        break;
                                }
                        } else {
                                epp = list_first_entry(
                                        &pages, struct efx_endpoint_page, link);
                                list_del(&epp->link);
                        }

                        list_add_tail(&epp->link, &efx->local_page_list);
                        peer = (struct vfdi_endpoint *)epp->ptr;
                        peer_space = EFX_PAGE_SIZE / sizeof(struct vfdi_endpoint);
                }
        }
        vfdi_status->peer_count = peer_count;
        mutex_unlock(&efx->local_lock);

        /* Free any now unused endpoint pages */
        while (!list_empty(&pages)) {
                epp = list_first_entry(
                        &pages, struct efx_endpoint_page, link);
                list_del(&epp->link);
                dma_free_coherent(&efx->pci_dev->dev, EFX_PAGE_SIZE,
                                  epp->ptr, epp->addr);
                kfree(epp);
        }

        /* Finally, push the pages */
        for (pos = 0; pos < efx->vf_count; ++pos) {
                vf = efx->vf + pos;

                mutex_lock(&vf->status_lock);
                if (vf->status_addr)
                        __efx_sriov_push_vf_status(vf);
                mutex_unlock(&vf->status_lock);
        }
}

static void efx_sriov_free_local(struct efx_nic *efx)
{
        struct efx_local_addr *local_addr;
        struct efx_endpoint_page *epp;

        while (!list_empty(&efx->local_addr_list)) {
                local_addr = list_first_entry(&efx->local_addr_list,
                                              struct efx_local_addr, link);
                list_del(&local_addr->link);
                kfree(local_addr);
        }

        while (!list_empty(&efx->local_page_list)) {
                epp = list_first_entry(&efx->local_page_list,
                                       struct efx_endpoint_page, link);
                list_del(&epp->link);
                dma_free_coherent(&efx->pci_dev->dev, EFX_PAGE_SIZE,
                                  epp->ptr, epp->addr);
                kfree(epp);
        }
}

static int efx_sriov_vf_alloc(struct efx_nic *efx)
{
        unsigned index;
        struct efx_vf *vf;

        efx->vf = kzalloc(sizeof(struct efx_vf) * efx->vf_count, GFP_KERNEL);
        if (!efx->vf)
                return -ENOMEM;

        for (index = 0; index < efx->vf_count; ++index) {
                vf = efx->vf + index;

                vf->efx = efx;
                vf->index = index;
                vf->rx_filter_id = -1;
                vf->tx_filter_mode = VF_TX_FILTER_AUTO;
                vf->tx_filter_id = -1;
                INIT_WORK(&vf->req, efx_sriov_vfdi);
                INIT_WORK(&vf->reset_work, efx_sriov_reset_vf_work);
                init_waitqueue_head(&vf->flush_waitq);
                mutex_init(&vf->status_lock);
                mutex_init(&vf->txq_lock);
        }

        return 0;
}

static void efx_sriov_vfs_fini(struct efx_nic *efx)
{
        struct efx_vf *vf;
        unsigned int pos;

        for (pos = 0; pos < efx->vf_count; ++pos) {
                vf = efx->vf + pos;

                efx_nic_free_buffer(efx, &vf->buf);
                kfree(vf->peer_page_addrs);
                vf->peer_page_addrs = NULL;
                vf->peer_page_count = 0;

                vf->evq0_count = 0;
        }
}

static int efx_sriov_vfs_init(struct efx_nic *efx)
{
        struct pci_dev *pci_dev = efx->pci_dev;
        unsigned index, devfn, sriov, buftbl_base;
        u16 offset, stride;
        struct efx_vf *vf;
        int rc;

        sriov = pci_find_ext_capability(pci_dev, PCI_EXT_CAP_ID_SRIOV);
        if (!sriov)
                return -ENOENT;

        pci_read_config_word(pci_dev, sriov + PCI_SRIOV_VF_OFFSET, &offset);
        pci_read_config_word(pci_dev, sriov + PCI_SRIOV_VF_STRIDE, &stride);

        buftbl_base = efx->vf_buftbl_base;
        devfn = pci_dev->devfn + offset;
        for (index = 0; index < efx->vf_count; ++index) {
                vf = efx->vf + index;

                /* Reserve buffer entries */
                vf->buftbl_base = buftbl_base;
                buftbl_base += EFX_VF_BUFTBL_PER_VI * efx_vf_size(efx);

                vf->pci_rid = devfn;
                snprintf(vf->pci_name, sizeof(vf->pci_name),
                         "%04x:%02x:%02x.%d",
                         pci_domain_nr(pci_dev->bus), pci_dev->bus->number,
                         PCI_SLOT(devfn), PCI_FUNC(devfn));

                rc = efx_nic_alloc_buffer(efx, &vf->buf, EFX_PAGE_SIZE);
                if (rc)
                        goto fail;

                devfn += stride;
        }

        return 0;

fail:
        efx_sriov_vfs_fini(efx);
        return rc;
}

int efx_sriov_init(struct efx_nic *efx)
{
        struct net_device *net_dev = efx->net_dev;
        struct vfdi_status *vfdi_status;
        int rc;

        /* Ensure there's room for vf_channel */
        BUILD_BUG_ON(EFX_MAX_CHANNELS + 1 >= EFX_VI_BASE);
        /* Ensure that VI_BASE is aligned on VI_SCALE */
        BUILD_BUG_ON(EFX_VI_BASE & ((1 << EFX_VI_SCALE_MAX) - 1));

        if (efx->vf_count == 0)
                return 0;

        rc = efx_sriov_cmd(efx, true, NULL, NULL);
        if (rc)
                goto fail_cmd;

        rc = efx_nic_alloc_buffer(efx, &efx->vfdi_status, sizeof(*vfdi_status));
        if (rc)
                goto fail_status;
        vfdi_status = efx->vfdi_status.addr;
        memset(vfdi_status, 0, sizeof(*vfdi_status));
        vfdi_status->version = 1;
        vfdi_status->length = sizeof(*vfdi_status);
        vfdi_status->max_tx_channels = vf_max_tx_channels;
        vfdi_status->vi_scale = efx->vi_scale;
        vfdi_status->rss_rxq_count = efx->rss_spread;
        vfdi_status->peer_count = 1 + efx->vf_count;
        vfdi_status->timer_quantum_ns = efx->timer_quantum_ns;

        rc = efx_sriov_vf_alloc(efx);
        if (rc)
                goto fail_alloc;

        mutex_init(&efx->local_lock);
        INIT_WORK(&efx->peer_work, efx_sriov_peer_work);
        INIT_LIST_HEAD(&efx->local_addr_list);
        INIT_LIST_HEAD(&efx->local_page_list);

        rc = efx_sriov_vfs_init(efx);
        if (rc)
                goto fail_vfs;

        rtnl_lock();
        memcpy(vfdi_status->peers[0].mac_addr,
               net_dev->dev_addr, ETH_ALEN);
        efx->vf_init_count = efx->vf_count;
        rtnl_unlock();

        efx_sriov_usrev(efx, true);

        /* At this point we must be ready to accept VFDI requests */

        rc = pci_enable_sriov(efx->pci_dev, efx->vf_count);
        if (rc)
                goto fail_pci;

        netif_info(efx, probe, net_dev,
                   "enabled SR-IOV for %d VFs, %d VI per VF\n",
                   efx->vf_count, efx_vf_size(efx));
        return 0;

fail_pci:
        efx_sriov_usrev(efx, false);
        rtnl_lock();
        efx->vf_init_count = 0;
        rtnl_unlock();
        efx_sriov_vfs_fini(efx);
fail_vfs:
        cancel_work_sync(&efx->peer_work);
        efx_sriov_free_local(efx);
        kfree(efx->vf);
fail_alloc:
        efx_nic_free_buffer(efx, &efx->vfdi_status);
fail_status:
        efx_sriov_cmd(efx, false, NULL, NULL);
fail_cmd:
        return rc;
}

void efx_sriov_fini(struct efx_nic *efx)
{
        struct efx_vf *vf;
        unsigned int pos;

        if (efx->vf_init_count == 0)
                return;

        /* Disable all interfaces to reconfiguration */
        BUG_ON(efx->vfdi_channel->enabled);
        efx_sriov_usrev(efx, false);
        rtnl_lock();
        efx->vf_init_count = 0;
        rtnl_unlock();

        /* Flush all reconfiguration work */
        for (pos = 0; pos < efx->vf_count; ++pos) {
                vf = efx->vf + pos;
                cancel_work_sync(&vf->req);
                cancel_work_sync(&vf->reset_work);
        }
        cancel_work_sync(&efx->peer_work);

        pci_disable_sriov(efx->pci_dev);

        /* Tear down back-end state */
        efx_sriov_vfs_fini(efx);
        efx_sriov_free_local(efx);
        kfree(efx->vf);
        efx_nic_free_buffer(efx, &efx->vfdi_status);
        efx_sriov_cmd(efx, false, NULL, NULL);
}

void efx_sriov_event(struct efx_channel *channel, efx_qword_t *event)
{
        struct efx_nic *efx = channel->efx;
        struct efx_vf *vf;
        unsigned qid, seq, type, data;

        qid = EFX_QWORD_FIELD(*event, FSF_CZ_USER_QID);

        /* USR_EV_REG_VALUE is dword0, so access the VFDI_EV fields directly */
        BUILD_BUG_ON(FSF_CZ_USER_EV_REG_VALUE_LBN != 0);
        seq = EFX_QWORD_FIELD(*event, VFDI_EV_SEQ);
        type = EFX_QWORD_FIELD(*event, VFDI_EV_TYPE);
        data = EFX_QWORD_FIELD(*event, VFDI_EV_DATA);

        netif_vdbg(efx, hw, efx->net_dev,
                   "USR_EV event from qid %d seq 0x%x type %d data 0x%x\n",
                   qid, seq, type, data);

        if (map_vi_index(efx, qid, &vf, NULL))
                return;
        if (vf->busy)
                goto error;

        if (type == VFDI_EV_TYPE_REQ_WORD0) {
                /* Resynchronise */
                vf->req_type = VFDI_EV_TYPE_REQ_WORD0;
                vf->req_seqno = seq + 1;
                vf->req_addr = 0;
        } else if (seq != (vf->req_seqno++ & 0xff) || type != vf->req_type)
                goto error;

        switch (vf->req_type) {
        case VFDI_EV_TYPE_REQ_WORD0:
        case VFDI_EV_TYPE_REQ_WORD1:
        case VFDI_EV_TYPE_REQ_WORD2:
                vf->req_addr |= (u64)data << (vf->req_type << 4);
                ++vf->req_type;
                return;

        case VFDI_EV_TYPE_REQ_WORD3:
                vf->req_addr |= (u64)data << 48;
                vf->req_type = VFDI_EV_TYPE_REQ_WORD0;
                vf->busy = true;
                queue_work(vfdi_workqueue, &vf->req);
                return;
        }

error:
        if (net_ratelimit())
                netif_err(efx, hw, efx->net_dev,
                          "ERROR: Screaming VFDI request from %s\n",
                          vf->pci_name);
        /* Reset the request and sequence number */
        vf->req_type = VFDI_EV_TYPE_REQ_WORD0;
        vf->req_seqno = seq + 1;
}

void efx_sriov_flr(struct efx_nic *efx, unsigned vf_i)
{
        struct efx_vf *vf;

        if (vf_i > efx->vf_init_count)
                return;
        vf = efx->vf + vf_i;
        netif_info(efx, hw, efx->net_dev,
                   "FLR on VF %s\n", vf->pci_name);

        vf->status_addr = 0;
        efx_vfdi_remove_all_filters(vf);
        efx_vfdi_flush_clear(vf);

        vf->evq0_count = 0;
}

void efx_sriov_mac_address_changed(struct efx_nic *efx)
{
        struct vfdi_status *vfdi_status = efx->vfdi_status.addr;

        if (!efx->vf_init_count)
                return;
        memcpy(vfdi_status->peers[0].mac_addr,
               efx->net_dev->dev_addr, ETH_ALEN);
        queue_work(vfdi_workqueue, &efx->peer_work);
}

void efx_sriov_tx_flush_done(struct efx_nic *efx, efx_qword_t *event)
{
        struct efx_vf *vf;
        unsigned queue, qid;

        queue = EFX_QWORD_FIELD(*event,  FSF_AZ_DRIVER_EV_SUBDATA);
        if (map_vi_index(efx, queue, &vf, &qid))
                return;
        /* Ignore flush completions triggered by an FLR */
        if (!test_bit(qid, vf->txq_mask))
                return;

        __clear_bit(qid, vf->txq_mask);
        --vf->txq_count;

        if (efx_vfdi_flush_wake(vf))
                wake_up(&vf->flush_waitq);
}

void efx_sriov_rx_flush_done(struct efx_nic *efx, efx_qword_t *event)
{
        struct efx_vf *vf;
        unsigned ev_failed, queue, qid;

        queue = EFX_QWORD_FIELD(*event, FSF_AZ_DRIVER_EV_RX_DESCQ_ID);
        ev_failed = EFX_QWORD_FIELD(*event,
                                    FSF_AZ_DRIVER_EV_RX_FLUSH_FAIL);
        if (map_vi_index(efx, queue, &vf, &qid))
                return;
        if (!test_bit(qid, vf->rxq_mask))
                return;

        if (ev_failed) {
                set_bit(qid, vf->rxq_retry_mask);
                atomic_inc(&vf->rxq_retry_count);
        } else {
                __clear_bit(qid, vf->rxq_mask);
                --vf->rxq_count;
        }
        if (efx_vfdi_flush_wake(vf))
                wake_up(&vf->flush_waitq);
}

/* Called from napi. Schedule the reset work item */
void efx_sriov_desc_fetch_err(struct efx_nic *efx, unsigned dmaq)
{
        struct efx_vf *vf;
        unsigned int rel;

        if (map_vi_index(efx, dmaq, &vf, &rel))
                return;

        if (net_ratelimit())
                netif_err(efx, hw, efx->net_dev,
                          "VF %d DMA Q %d reports descriptor fetch error.\n",
                          vf->index, rel);
        queue_work(vfdi_workqueue, &vf->reset_work);
}

/* Reset all VFs */
void efx_sriov_reset(struct efx_nic *efx)
{
        unsigned int vf_i;
        struct efx_buffer buf;
        struct efx_vf *vf;

        ASSERT_RTNL();

        if (efx->vf_init_count == 0)
                return;

        efx_sriov_usrev(efx, true);
        (void)efx_sriov_cmd(efx, true, NULL, NULL);

        if (efx_nic_alloc_buffer(efx, &buf, EFX_PAGE_SIZE))
                return;

        for (vf_i = 0; vf_i < efx->vf_init_count; ++vf_i) {
                vf = efx->vf + vf_i;
                efx_sriov_reset_vf(vf, &buf);
        }

        efx_nic_free_buffer(efx, &buf);
}

int efx_init_sriov(void)
{
        /* A single threaded workqueue is sufficient. efx_sriov_vfdi() and
         * efx_sriov_peer_work() spend almost all their time sleeping for
         * MCDI to complete anyway
         */
        vfdi_workqueue = create_singlethread_workqueue("sfc_vfdi");
        if (!vfdi_workqueue)
                return -ENOMEM;

        return 0;
}

void efx_fini_sriov(void)
{
        destroy_workqueue(vfdi_workqueue);
}

int efx_sriov_set_vf_mac(struct net_device *net_dev, int vf_i, u8 *mac)
{
        struct efx_nic *efx = netdev_priv(net_dev);
        struct efx_vf *vf;

        if (vf_i >= efx->vf_init_count)
                return -EINVAL;
        vf = efx->vf + vf_i;

        mutex_lock(&vf->status_lock);
        memcpy(vf->addr.mac_addr, mac, ETH_ALEN);
        __efx_sriov_update_vf_addr(vf);
        mutex_unlock(&vf->status_lock);

        return 0;
}

int efx_sriov_set_vf_vlan(struct net_device *net_dev, int vf_i,
                          u16 vlan, u8 qos)
{
        struct efx_nic *efx = netdev_priv(net_dev);
        struct efx_vf *vf;
        u16 tci;

        if (vf_i >= efx->vf_init_count)
                return -EINVAL;
        vf = efx->vf + vf_i;

        mutex_lock(&vf->status_lock);
        tci = (vlan & VLAN_VID_MASK) | ((qos & 0x7) << VLAN_PRIO_SHIFT);
        vf->addr.tci = htons(tci);
        __efx_sriov_update_vf_addr(vf);
        mutex_unlock(&vf->status_lock);

        return 0;
}

int efx_sriov_set_vf_spoofchk(struct net_device *net_dev, int vf_i,
                              bool spoofchk)
{
        struct efx_nic *efx = netdev_priv(net_dev);
        struct efx_vf *vf;
        int rc;

        if (vf_i >= efx->vf_init_count)
                return -EINVAL;
        vf = efx->vf + vf_i;

        mutex_lock(&vf->txq_lock);
        if (vf->txq_count == 0) {
                vf->tx_filter_mode =
                        spoofchk ? VF_TX_FILTER_ON : VF_TX_FILTER_OFF;
                rc = 0;
        } else {
                /* This cannot be changed while TX queues are running */
                rc = -EBUSY;
        }
        mutex_unlock(&vf->txq_lock);
        return rc;
}

int efx_sriov_get_vf_config(struct net_device *net_dev, int vf_i,
                            struct ifla_vf_info *ivi)
{
        struct efx_nic *efx = netdev_priv(net_dev);
        struct efx_vf *vf;
        u16 tci;

        if (vf_i >= efx->vf_init_count)
                return -EINVAL;
        vf = efx->vf + vf_i;

        ivi->vf = vf_i;
        memcpy(ivi->mac, vf->addr.mac_addr, ETH_ALEN);
        ivi->tx_rate = 0;
        tci = ntohs(vf->addr.tci);
        ivi->vlan = tci & VLAN_VID_MASK;
        ivi->qos = (tci >> VLAN_PRIO_SHIFT) & 0x7;
        ivi->spoofchk = vf->tx_filter_mode == VF_TX_FILTER_ON;

        return 0;
}