treewide: remove redundant IS_ERR() before error code check

[linux/fpc-iii.git] / drivers / net / ethernet / qlogic / qed / qed_spq.c

/* QLogic qed NIC Driver
 * Copyright (c) 2015-2017  QLogic Corporation
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and /or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/types.h>
#include <asm/byteorder.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include "qed.h"
#include "qed_cxt.h"
#include "qed_dev_api.h"
#include "qed_hsi.h"
#include "qed_hw.h"
#include "qed_int.h"
#include "qed_iscsi.h"
#include "qed_mcp.h"
#include "qed_ooo.h"
#include "qed_reg_addr.h"
#include "qed_sp.h"
#include "qed_sriov.h"
#include "qed_rdma.h"

/***************************************************************************
* Structures & Definitions
***************************************************************************/

#define SPQ_HIGH_PRI_RESERVE_DEFAULT    (1)

#define SPQ_BLOCK_DELAY_MAX_ITER        (10)
#define SPQ_BLOCK_DELAY_US              (10)
#define SPQ_BLOCK_SLEEP_MAX_ITER        (1000)
#define SPQ_BLOCK_SLEEP_MS              (5)

/***************************************************************************
* Blocking Imp. (BLOCK/EBLOCK mode)
***************************************************************************/
static void qed_spq_blocking_cb(struct qed_hwfn *p_hwfn,
                                void *cookie,
                                union event_ring_data *data, u8 fw_return_code)
{
        struct qed_spq_comp_done *comp_done;

        comp_done = (struct qed_spq_comp_done *)cookie;

        comp_done->fw_return_code = fw_return_code;

        /* Make sure completion done is visible on waiting thread */
        smp_store_release(&comp_done->done, 0x1);
}

static int __qed_spq_block(struct qed_hwfn *p_hwfn,
                           struct qed_spq_entry *p_ent,
                           u8 *p_fw_ret, bool sleep_between_iter)
{
        struct qed_spq_comp_done *comp_done;
        u32 iter_cnt;

        comp_done = (struct qed_spq_comp_done *)p_ent->comp_cb.cookie;
        iter_cnt = sleep_between_iter ? SPQ_BLOCK_SLEEP_MAX_ITER
                                      : SPQ_BLOCK_DELAY_MAX_ITER;

        while (iter_cnt--) {
                /* Validate we receive completion update */
                if (smp_load_acquire(&comp_done->done) == 1) { /* ^^^ */
                        if (p_fw_ret)
                                *p_fw_ret = comp_done->fw_return_code;
                        return 0;
                }

                if (sleep_between_iter)
                        msleep(SPQ_BLOCK_SLEEP_MS);
                else
                        udelay(SPQ_BLOCK_DELAY_US);
        }

        return -EBUSY;
}

static int qed_spq_block(struct qed_hwfn *p_hwfn,
                         struct qed_spq_entry *p_ent,
                         u8 *p_fw_ret, bool skip_quick_poll)
{
        struct qed_spq_comp_done *comp_done;
        struct qed_ptt *p_ptt;
        int rc;

        /* A relatively short polling period w/o sleeping, to allow the FW to
         * complete the ramrod and thus possibly to avoid the following sleeps.
         */
        if (!skip_quick_poll) {
                rc = __qed_spq_block(p_hwfn, p_ent, p_fw_ret, false);
                if (!rc)
                        return 0;
        }

        /* Move to polling with a sleeping period between iterations */
        rc = __qed_spq_block(p_hwfn, p_ent, p_fw_ret, true);
        if (!rc)
                return 0;

        p_ptt = qed_ptt_acquire(p_hwfn);
        if (!p_ptt) {
                DP_NOTICE(p_hwfn, "ptt, failed to acquire\n");
                return -EAGAIN;
        }

        DP_INFO(p_hwfn, "Ramrod is stuck, requesting MCP drain\n");
        rc = qed_mcp_drain(p_hwfn, p_ptt);
        qed_ptt_release(p_hwfn, p_ptt);
        if (rc) {
                DP_NOTICE(p_hwfn, "MCP drain failed\n");
                goto err;
        }

        /* Retry after drain */
        rc = __qed_spq_block(p_hwfn, p_ent, p_fw_ret, true);
        if (!rc)
                return 0;

        comp_done = (struct qed_spq_comp_done *)p_ent->comp_cb.cookie;
        if (comp_done->done == 1) {
                if (p_fw_ret)
                        *p_fw_ret = comp_done->fw_return_code;
                return 0;
        }
err:
        DP_NOTICE(p_hwfn,
                  "Ramrod is stuck [CID %08x cmd %02x protocol %02x echo %04x]\n",
                  le32_to_cpu(p_ent->elem.hdr.cid),
                  p_ent->elem.hdr.cmd_id,
                  p_ent->elem.hdr.protocol_id,
                  le16_to_cpu(p_ent->elem.hdr.echo));

        return -EBUSY;
}

/***************************************************************************
* SPQ entries inner API
***************************************************************************/
static int qed_spq_fill_entry(struct qed_hwfn *p_hwfn,
                              struct qed_spq_entry *p_ent)
{
        p_ent->flags = 0;

        switch (p_ent->comp_mode) {
        case QED_SPQ_MODE_EBLOCK:
        case QED_SPQ_MODE_BLOCK:
                p_ent->comp_cb.function = qed_spq_blocking_cb;
                break;
        case QED_SPQ_MODE_CB:
                break;
        default:
                DP_NOTICE(p_hwfn, "Unknown SPQE completion mode %d\n",
                          p_ent->comp_mode);
                return -EINVAL;
        }

        DP_VERBOSE(p_hwfn, QED_MSG_SPQ,
                   "Ramrod header: [CID 0x%08x CMD 0x%02x protocol 0x%02x] Data pointer: [%08x:%08x] Completion Mode: %s\n",
                   p_ent->elem.hdr.cid,
                   p_ent->elem.hdr.cmd_id,
                   p_ent->elem.hdr.protocol_id,
                   p_ent->elem.data_ptr.hi,
                   p_ent->elem.data_ptr.lo,
                   D_TRINE(p_ent->comp_mode, QED_SPQ_MODE_EBLOCK,
                           QED_SPQ_MODE_BLOCK, "MODE_EBLOCK", "MODE_BLOCK",
                           "MODE_CB"));

        return 0;
}

/***************************************************************************
* HSI access
***************************************************************************/
static void qed_spq_hw_initialize(struct qed_hwfn *p_hwfn,
                                  struct qed_spq *p_spq)
{
        struct e4_core_conn_context *p_cxt;
        struct qed_cxt_info cxt_info;
        u16 physical_q;
        int rc;

        cxt_info.iid = p_spq->cid;

        rc = qed_cxt_get_cid_info(p_hwfn, &cxt_info);

        if (rc < 0) {
                DP_NOTICE(p_hwfn, "Cannot find context info for cid=%d\n",
                          p_spq->cid);
                return;
        }

        p_cxt = cxt_info.p_cxt;

        SET_FIELD(p_cxt->xstorm_ag_context.flags10,
                  E4_XSTORM_CORE_CONN_AG_CTX_DQ_CF_EN, 1);
        SET_FIELD(p_cxt->xstorm_ag_context.flags1,
                  E4_XSTORM_CORE_CONN_AG_CTX_DQ_CF_ACTIVE, 1);
        SET_FIELD(p_cxt->xstorm_ag_context.flags9,
                  E4_XSTORM_CORE_CONN_AG_CTX_CONSOLID_PROD_CF_EN, 1);

        /* QM physical queue */
        physical_q = qed_get_cm_pq_idx(p_hwfn, PQ_FLAGS_LB);
        p_cxt->xstorm_ag_context.physical_q0 = cpu_to_le16(physical_q);

        p_cxt->xstorm_st_context.spq_base_lo =
                DMA_LO_LE(p_spq->chain.p_phys_addr);
        p_cxt->xstorm_st_context.spq_base_hi =
                DMA_HI_LE(p_spq->chain.p_phys_addr);

        DMA_REGPAIR_LE(p_cxt->xstorm_st_context.consolid_base_addr,
                       p_hwfn->p_consq->chain.p_phys_addr);
}

static int qed_spq_hw_post(struct qed_hwfn *p_hwfn,
                           struct qed_spq *p_spq, struct qed_spq_entry *p_ent)
{
        struct qed_chain *p_chain = &p_hwfn->p_spq->chain;
        struct core_db_data *p_db_data = &p_spq->db_data;
        u16 echo = qed_chain_get_prod_idx(p_chain);
        struct slow_path_element        *elem;

        p_ent->elem.hdr.echo    = cpu_to_le16(echo);
        elem = qed_chain_produce(p_chain);
        if (!elem) {
                DP_NOTICE(p_hwfn, "Failed to produce from SPQ chain\n");
                return -EINVAL;
        }

        *elem = p_ent->elem; /* struct assignment */

        /* send a doorbell on the slow hwfn session */
        p_db_data->spq_prod = cpu_to_le16(qed_chain_get_prod_idx(p_chain));

        /* make sure the SPQE is updated before the doorbell */
        wmb();

        DOORBELL(p_hwfn, p_spq->db_addr_offset, *(u32 *)p_db_data);

        /* make sure doorbell is rang */
        wmb();

        DP_VERBOSE(p_hwfn, QED_MSG_SPQ,
                   "Doorbelled [0x%08x, CID 0x%08x] with Flags: %02x agg_params: %02x, prod: %04x\n",
                   p_spq->db_addr_offset,
                   p_spq->cid,
                   p_db_data->params,
                   p_db_data->agg_flags, qed_chain_get_prod_idx(p_chain));

        return 0;
}

/***************************************************************************
* Asynchronous events
***************************************************************************/
static int
qed_async_event_completion(struct qed_hwfn *p_hwfn,
                           struct event_ring_entry *p_eqe)
{
        qed_spq_async_comp_cb cb;

        if (!p_hwfn->p_spq || (p_eqe->protocol_id >= MAX_PROTOCOL_TYPE))
                return -EINVAL;

        cb = p_hwfn->p_spq->async_comp_cb[p_eqe->protocol_id];
        if (cb) {
                return cb(p_hwfn, p_eqe->opcode, p_eqe->echo,
                          &p_eqe->data, p_eqe->fw_return_code);
        } else {
                DP_NOTICE(p_hwfn,
                          "Unknown Async completion for protocol: %d\n",
                          p_eqe->protocol_id);
                return -EINVAL;
        }
}

int
qed_spq_register_async_cb(struct qed_hwfn *p_hwfn,
                          enum protocol_type protocol_id,
                          qed_spq_async_comp_cb cb)
{
        if (!p_hwfn->p_spq || (protocol_id >= MAX_PROTOCOL_TYPE))
                return -EINVAL;

        p_hwfn->p_spq->async_comp_cb[protocol_id] = cb;
        return 0;
}

void
qed_spq_unregister_async_cb(struct qed_hwfn *p_hwfn,
                            enum protocol_type protocol_id)
{
        if (!p_hwfn->p_spq || (protocol_id >= MAX_PROTOCOL_TYPE))
                return;

        p_hwfn->p_spq->async_comp_cb[protocol_id] = NULL;
}

/***************************************************************************
* EQ API
***************************************************************************/
void qed_eq_prod_update(struct qed_hwfn *p_hwfn, u16 prod)
{
        u32 addr = GTT_BAR0_MAP_REG_USDM_RAM +
                   USTORM_EQE_CONS_OFFSET(p_hwfn->rel_pf_id);

        REG_WR16(p_hwfn, addr, prod);
}

int qed_eq_completion(struct qed_hwfn *p_hwfn, void *cookie)
{
        struct qed_eq *p_eq = cookie;
        struct qed_chain *p_chain = &p_eq->chain;
        int rc = 0;

        /* take a snapshot of the FW consumer */
        u16 fw_cons_idx = le16_to_cpu(*p_eq->p_fw_cons);

        DP_VERBOSE(p_hwfn, QED_MSG_SPQ, "fw_cons_idx %x\n", fw_cons_idx);

        /* Need to guarantee the fw_cons index we use points to a usuable
         * element (to comply with our chain), so our macros would comply
         */
        if ((fw_cons_idx & qed_chain_get_usable_per_page(p_chain)) ==
            qed_chain_get_usable_per_page(p_chain))
                fw_cons_idx += qed_chain_get_unusable_per_page(p_chain);

        /* Complete current segment of eq entries */
        while (fw_cons_idx != qed_chain_get_cons_idx(p_chain)) {
                struct event_ring_entry *p_eqe = qed_chain_consume(p_chain);

                if (!p_eqe) {
                        rc = -EINVAL;
                        break;
                }

                DP_VERBOSE(p_hwfn, QED_MSG_SPQ,
                           "op %x prot %x res0 %x echo %x fwret %x flags %x\n",
                           p_eqe->opcode,
                           p_eqe->protocol_id,
                           p_eqe->reserved0,
                           le16_to_cpu(p_eqe->echo),
                           p_eqe->fw_return_code,
                           p_eqe->flags);

                if (GET_FIELD(p_eqe->flags, EVENT_RING_ENTRY_ASYNC)) {
                        if (qed_async_event_completion(p_hwfn, p_eqe))
                                rc = -EINVAL;
                } else if (qed_spq_completion(p_hwfn,
                                              p_eqe->echo,
                                              p_eqe->fw_return_code,
                                              &p_eqe->data)) {
                        rc = -EINVAL;
                }

                qed_chain_recycle_consumed(p_chain);
        }

        qed_eq_prod_update(p_hwfn, qed_chain_get_prod_idx(p_chain));

        /* Attempt to post pending requests */
        spin_lock_bh(&p_hwfn->p_spq->lock);
        rc = qed_spq_pend_post(p_hwfn);
        spin_unlock_bh(&p_hwfn->p_spq->lock);

        return rc;
}

int qed_eq_alloc(struct qed_hwfn *p_hwfn, u16 num_elem)
{
        struct qed_eq *p_eq;

        /* Allocate EQ struct */
        p_eq = kzalloc(sizeof(*p_eq), GFP_KERNEL);
        if (!p_eq)
                return -ENOMEM;

        /* Allocate and initialize EQ chain*/
        if (qed_chain_alloc(p_hwfn->cdev,
                            QED_CHAIN_USE_TO_PRODUCE,
                            QED_CHAIN_MODE_PBL,
                            QED_CHAIN_CNT_TYPE_U16,
                            num_elem,
                            sizeof(union event_ring_element),
                            &p_eq->chain, NULL))
                goto eq_allocate_fail;

        /* register EQ completion on the SP SB */
        qed_int_register_cb(p_hwfn, qed_eq_completion,
                            p_eq, &p_eq->eq_sb_index, &p_eq->p_fw_cons);

        p_hwfn->p_eq = p_eq;
        return 0;

eq_allocate_fail:
        kfree(p_eq);
        return -ENOMEM;
}

void qed_eq_setup(struct qed_hwfn *p_hwfn)
{
        qed_chain_reset(&p_hwfn->p_eq->chain);
}

void qed_eq_free(struct qed_hwfn *p_hwfn)
{
        if (!p_hwfn->p_eq)
                return;

        qed_chain_free(p_hwfn->cdev, &p_hwfn->p_eq->chain);

        kfree(p_hwfn->p_eq);
        p_hwfn->p_eq = NULL;
}

/***************************************************************************
* CQE API - manipulate EQ functionality
***************************************************************************/
static int qed_cqe_completion(struct qed_hwfn *p_hwfn,
                              struct eth_slow_path_rx_cqe *cqe,
                              enum protocol_type protocol)
{
        if (IS_VF(p_hwfn->cdev))
                return 0;

        /* @@@tmp - it's possible we'll eventually want to handle some
         * actual commands that can arrive here, but for now this is only
         * used to complete the ramrod using the echo value on the cqe
         */
        return qed_spq_completion(p_hwfn, cqe->echo, 0, NULL);
}

int qed_eth_cqe_completion(struct qed_hwfn *p_hwfn,
                           struct eth_slow_path_rx_cqe *cqe)
{
        int rc;

        rc = qed_cqe_completion(p_hwfn, cqe, PROTOCOLID_ETH);
        if (rc)
                DP_NOTICE(p_hwfn,
                          "Failed to handle RXQ CQE [cmd 0x%02x]\n",
                          cqe->ramrod_cmd_id);

        return rc;
}

/***************************************************************************
* Slow hwfn Queue (spq)
***************************************************************************/
void qed_spq_setup(struct qed_hwfn *p_hwfn)
{
        struct qed_spq *p_spq = p_hwfn->p_spq;
        struct qed_spq_entry *p_virt = NULL;
        struct core_db_data *p_db_data;
        void __iomem *db_addr;
        dma_addr_t p_phys = 0;
        u32 i, capacity;
        int rc;

        INIT_LIST_HEAD(&p_spq->pending);
        INIT_LIST_HEAD(&p_spq->completion_pending);
        INIT_LIST_HEAD(&p_spq->free_pool);
        INIT_LIST_HEAD(&p_spq->unlimited_pending);
        spin_lock_init(&p_spq->lock);

        /* SPQ empty pool */
        p_phys  = p_spq->p_phys + offsetof(struct qed_spq_entry, ramrod);
        p_virt  = p_spq->p_virt;

        capacity = qed_chain_get_capacity(&p_spq->chain);
        for (i = 0; i < capacity; i++) {
                DMA_REGPAIR_LE(p_virt->elem.data_ptr, p_phys);

                list_add_tail(&p_virt->list, &p_spq->free_pool);

                p_virt++;
                p_phys += sizeof(struct qed_spq_entry);
        }

        /* Statistics */
        p_spq->normal_count             = 0;
        p_spq->comp_count               = 0;
        p_spq->comp_sent_count          = 0;
        p_spq->unlimited_pending_count  = 0;

        bitmap_zero(p_spq->p_comp_bitmap, SPQ_RING_SIZE);
        p_spq->comp_bitmap_idx = 0;

        /* SPQ cid, cannot fail */
        qed_cxt_acquire_cid(p_hwfn, PROTOCOLID_CORE, &p_spq->cid);
        qed_spq_hw_initialize(p_hwfn, p_spq);

        /* reset the chain itself */
        qed_chain_reset(&p_spq->chain);

        /* Initialize the address/data of the SPQ doorbell */
        p_spq->db_addr_offset = qed_db_addr(p_spq->cid, DQ_DEMS_LEGACY);
        p_db_data = &p_spq->db_data;
        memset(p_db_data, 0, sizeof(*p_db_data));
        SET_FIELD(p_db_data->params, CORE_DB_DATA_DEST, DB_DEST_XCM);
        SET_FIELD(p_db_data->params, CORE_DB_DATA_AGG_CMD, DB_AGG_CMD_MAX);
        SET_FIELD(p_db_data->params, CORE_DB_DATA_AGG_VAL_SEL,
                  DQ_XCM_CORE_SPQ_PROD_CMD);
        p_db_data->agg_flags = DQ_XCM_CORE_DQ_CF_CMD;

        /* Register the SPQ doorbell with the doorbell recovery mechanism */
        db_addr = (void __iomem *)((u8 __iomem *)p_hwfn->doorbells +
                                   p_spq->db_addr_offset);
        rc = qed_db_recovery_add(p_hwfn->cdev, db_addr, &p_spq->db_data,
                                 DB_REC_WIDTH_32B, DB_REC_KERNEL);
        if (rc)
                DP_INFO(p_hwfn,
                        "Failed to register the SPQ doorbell with the doorbell recovery mechanism\n");
}

int qed_spq_alloc(struct qed_hwfn *p_hwfn)
{
        struct qed_spq_entry *p_virt = NULL;
        struct qed_spq *p_spq = NULL;
        dma_addr_t p_phys = 0;
        u32 capacity;

        /* SPQ struct */
        p_spq = kzalloc(sizeof(struct qed_spq), GFP_KERNEL);
        if (!p_spq)
                return -ENOMEM;

        /* SPQ ring  */
        if (qed_chain_alloc(p_hwfn->cdev,
                            QED_CHAIN_USE_TO_PRODUCE,
                            QED_CHAIN_MODE_SINGLE,
                            QED_CHAIN_CNT_TYPE_U16,
                            0,   /* N/A when the mode is SINGLE */
                            sizeof(struct slow_path_element),
                            &p_spq->chain, NULL))
                goto spq_allocate_fail;

        /* allocate and fill the SPQ elements (incl. ramrod data list) */
        capacity = qed_chain_get_capacity(&p_spq->chain);
        p_virt = dma_alloc_coherent(&p_hwfn->cdev->pdev->dev,
                                    capacity * sizeof(struct qed_spq_entry),
                                    &p_phys, GFP_KERNEL);
        if (!p_virt)
                goto spq_allocate_fail;

        p_spq->p_virt = p_virt;
        p_spq->p_phys = p_phys;
        p_hwfn->p_spq = p_spq;

        return 0;

spq_allocate_fail:
        qed_chain_free(p_hwfn->cdev, &p_spq->chain);
        kfree(p_spq);
        return -ENOMEM;
}

void qed_spq_free(struct qed_hwfn *p_hwfn)
{
        struct qed_spq *p_spq = p_hwfn->p_spq;
        void __iomem *db_addr;
        u32 capacity;

        if (!p_spq)
                return;

        /* Delete the SPQ doorbell from the doorbell recovery mechanism */
        db_addr = (void __iomem *)((u8 __iomem *)p_hwfn->doorbells +
                                   p_spq->db_addr_offset);
        qed_db_recovery_del(p_hwfn->cdev, db_addr, &p_spq->db_data);

        if (p_spq->p_virt) {
                capacity = qed_chain_get_capacity(&p_spq->chain);
                dma_free_coherent(&p_hwfn->cdev->pdev->dev,
                                  capacity *
                                  sizeof(struct qed_spq_entry),
                                  p_spq->p_virt, p_spq->p_phys);
        }

        qed_chain_free(p_hwfn->cdev, &p_spq->chain);
        kfree(p_spq);
        p_hwfn->p_spq = NULL;
}

int qed_spq_get_entry(struct qed_hwfn *p_hwfn, struct qed_spq_entry **pp_ent)
{
        struct qed_spq *p_spq = p_hwfn->p_spq;
        struct qed_spq_entry *p_ent = NULL;
        int rc = 0;

        spin_lock_bh(&p_spq->lock);

        if (list_empty(&p_spq->free_pool)) {
                p_ent = kzalloc(sizeof(*p_ent), GFP_ATOMIC);
                if (!p_ent) {
                        DP_NOTICE(p_hwfn,
                                  "Failed to allocate an SPQ entry for a pending ramrod\n");
                        rc = -ENOMEM;
                        goto out_unlock;
                }
                p_ent->queue = &p_spq->unlimited_pending;
        } else {
                p_ent = list_first_entry(&p_spq->free_pool,
                                         struct qed_spq_entry, list);
                list_del(&p_ent->list);
                p_ent->queue = &p_spq->pending;
        }

        *pp_ent = p_ent;

out_unlock:
        spin_unlock_bh(&p_spq->lock);
        return rc;
}

/* Locked variant; Should be called while the SPQ lock is taken */
static void __qed_spq_return_entry(struct qed_hwfn *p_hwfn,
                                   struct qed_spq_entry *p_ent)
{
        list_add_tail(&p_ent->list, &p_hwfn->p_spq->free_pool);
}

void qed_spq_return_entry(struct qed_hwfn *p_hwfn, struct qed_spq_entry *p_ent)
{
        spin_lock_bh(&p_hwfn->p_spq->lock);
        __qed_spq_return_entry(p_hwfn, p_ent);
        spin_unlock_bh(&p_hwfn->p_spq->lock);
}

/**
 * @brief qed_spq_add_entry - adds a new entry to the pending
 *        list. Should be used while lock is being held.
 *
 * Addes an entry to the pending list is there is room (en empty
 * element is available in the free_pool), or else places the
 * entry in the unlimited_pending pool.
 *
 * @param p_hwfn
 * @param p_ent
 * @param priority
 *
 * @return int
 */
static int qed_spq_add_entry(struct qed_hwfn *p_hwfn,
                             struct qed_spq_entry *p_ent,
                             enum spq_priority priority)
{
        struct qed_spq *p_spq = p_hwfn->p_spq;

        if (p_ent->queue == &p_spq->unlimited_pending) {

                if (list_empty(&p_spq->free_pool)) {
                        list_add_tail(&p_ent->list, &p_spq->unlimited_pending);
                        p_spq->unlimited_pending_count++;

                        return 0;
                } else {
                        struct qed_spq_entry *p_en2;

                        p_en2 = list_first_entry(&p_spq->free_pool,
                                                 struct qed_spq_entry, list);
                        list_del(&p_en2->list);

                        /* Copy the ring element physical pointer to the new
                         * entry, since we are about to override the entire ring
                         * entry and don't want to lose the pointer.
                         */
                        p_ent->elem.data_ptr = p_en2->elem.data_ptr;

                        *p_en2 = *p_ent;

                        /* EBLOCK responsible to free the allocated p_ent */
                        if (p_ent->comp_mode != QED_SPQ_MODE_EBLOCK)
                                kfree(p_ent);
                        else
                                p_ent->post_ent = p_en2;

                        p_ent = p_en2;
                }
        }

        /* entry is to be placed in 'pending' queue */
        switch (priority) {
        case QED_SPQ_PRIORITY_NORMAL:
                list_add_tail(&p_ent->list, &p_spq->pending);
                p_spq->normal_count++;
                break;
        case QED_SPQ_PRIORITY_HIGH:
                list_add(&p_ent->list, &p_spq->pending);
                p_spq->high_count++;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

/***************************************************************************
* Accessor
***************************************************************************/
u32 qed_spq_get_cid(struct qed_hwfn *p_hwfn)
{
        if (!p_hwfn->p_spq)
                return 0xffffffff;      /* illegal */
        return p_hwfn->p_spq->cid;
}

/***************************************************************************
* Posting new Ramrods
***************************************************************************/
static int qed_spq_post_list(struct qed_hwfn *p_hwfn,
                             struct list_head *head, u32 keep_reserve)
{
        struct qed_spq *p_spq = p_hwfn->p_spq;
        int rc;

        while (qed_chain_get_elem_left(&p_spq->chain) > keep_reserve &&
               !list_empty(head)) {
                struct qed_spq_entry *p_ent =
                        list_first_entry(head, struct qed_spq_entry, list);
                list_move_tail(&p_ent->list, &p_spq->completion_pending);
                p_spq->comp_sent_count++;

                rc = qed_spq_hw_post(p_hwfn, p_spq, p_ent);
                if (rc) {
                        list_del(&p_ent->list);
                        __qed_spq_return_entry(p_hwfn, p_ent);
                        return rc;
                }
        }

        return 0;
}

int qed_spq_pend_post(struct qed_hwfn *p_hwfn)
{
        struct qed_spq *p_spq = p_hwfn->p_spq;
        struct qed_spq_entry *p_ent = NULL;

        while (!list_empty(&p_spq->free_pool)) {
                if (list_empty(&p_spq->unlimited_pending))
                        break;

                p_ent = list_first_entry(&p_spq->unlimited_pending,
                                         struct qed_spq_entry, list);
                if (!p_ent)
                        return -EINVAL;

                list_del(&p_ent->list);

                qed_spq_add_entry(p_hwfn, p_ent, p_ent->priority);
        }

        return qed_spq_post_list(p_hwfn, &p_spq->pending,
                                 SPQ_HIGH_PRI_RESERVE_DEFAULT);
}

static void qed_spq_recov_set_ret_code(struct qed_spq_entry *p_ent,
                                       u8 *fw_return_code)
{
        if (!fw_return_code)
                return;

        if (p_ent->elem.hdr.protocol_id == PROTOCOLID_ROCE ||
            p_ent->elem.hdr.protocol_id == PROTOCOLID_IWARP)
                *fw_return_code = RDMA_RETURN_OK;
}

/* Avoid overriding of SPQ entries when getting out-of-order completions, by
 * marking the completions in a bitmap and increasing the chain consumer only
 * for the first successive completed entries.
 */
static void qed_spq_comp_bmap_update(struct qed_hwfn *p_hwfn, __le16 echo)
{
        u16 pos = le16_to_cpu(echo) % SPQ_RING_SIZE;
        struct qed_spq *p_spq = p_hwfn->p_spq;

        __set_bit(pos, p_spq->p_comp_bitmap);
        while (test_bit(p_spq->comp_bitmap_idx,
                        p_spq->p_comp_bitmap)) {
                __clear_bit(p_spq->comp_bitmap_idx,
                            p_spq->p_comp_bitmap);
                p_spq->comp_bitmap_idx++;
                qed_chain_return_produced(&p_spq->chain);
        }
}

int qed_spq_post(struct qed_hwfn *p_hwfn,
                 struct qed_spq_entry *p_ent, u8 *fw_return_code)
{
        int rc = 0;
        struct qed_spq *p_spq = p_hwfn ? p_hwfn->p_spq : NULL;
        bool b_ret_ent = true;
        bool eblock;

        if (!p_hwfn)
                return -EINVAL;

        if (!p_ent) {
                DP_NOTICE(p_hwfn, "Got a NULL pointer\n");
                return -EINVAL;
        }

        if (p_hwfn->cdev->recov_in_prog) {
                DP_VERBOSE(p_hwfn,
                           QED_MSG_SPQ,
                           "Recovery is in progress. Skip spq post [cmd %02x protocol %02x]\n",
                           p_ent->elem.hdr.cmd_id, p_ent->elem.hdr.protocol_id);

                /* Let the flow complete w/o any error handling */
                qed_spq_recov_set_ret_code(p_ent, fw_return_code);
                return 0;
        }

        /* Complete the entry */
        rc = qed_spq_fill_entry(p_hwfn, p_ent);

        spin_lock_bh(&p_spq->lock);

        /* Check return value after LOCK is taken for cleaner error flow */
        if (rc)
                goto spq_post_fail;

        /* Check if entry is in block mode before qed_spq_add_entry,
         * which might kfree p_ent.
         */
        eblock = (p_ent->comp_mode == QED_SPQ_MODE_EBLOCK);

        /* Add the request to the pending queue */
        rc = qed_spq_add_entry(p_hwfn, p_ent, p_ent->priority);
        if (rc)
                goto spq_post_fail;

        rc = qed_spq_pend_post(p_hwfn);
        if (rc) {
                /* Since it's possible that pending failed for a different
                 * entry [although unlikely], the failed entry was already
                 * dealt with; No need to return it here.
                 */
                b_ret_ent = false;
                goto spq_post_fail;
        }

        spin_unlock_bh(&p_spq->lock);

        if (eblock) {
                /* For entries in QED BLOCK mode, the completion code cannot
                 * perform the necessary cleanup - if it did, we couldn't
                 * access p_ent here to see whether it's successful or not.
                 * Thus, after gaining the answer perform the cleanup here.
                 */
                rc = qed_spq_block(p_hwfn, p_ent, fw_return_code,
                                   p_ent->queue == &p_spq->unlimited_pending);

                if (p_ent->queue == &p_spq->unlimited_pending) {
                        struct qed_spq_entry *p_post_ent = p_ent->post_ent;

                        kfree(p_ent);

                        /* Return the entry which was actually posted */
                        p_ent = p_post_ent;
                }

                if (rc)
                        goto spq_post_fail2;

                /* return to pool */
                qed_spq_return_entry(p_hwfn, p_ent);
        }
        return rc;

spq_post_fail2:
        spin_lock_bh(&p_spq->lock);
        list_del(&p_ent->list);
        qed_spq_comp_bmap_update(p_hwfn, p_ent->elem.hdr.echo);

spq_post_fail:
        /* return to the free pool */
        if (b_ret_ent)
                __qed_spq_return_entry(p_hwfn, p_ent);
        spin_unlock_bh(&p_spq->lock);

        return rc;
}

int qed_spq_completion(struct qed_hwfn *p_hwfn,
                       __le16 echo,
                       u8 fw_return_code,
                       union event_ring_data *p_data)
{
        struct qed_spq          *p_spq;
        struct qed_spq_entry    *p_ent = NULL;
        struct qed_spq_entry    *tmp;
        struct qed_spq_entry    *found = NULL;

        if (!p_hwfn)
                return -EINVAL;

        p_spq = p_hwfn->p_spq;
        if (!p_spq)
                return -EINVAL;

        spin_lock_bh(&p_spq->lock);
        list_for_each_entry_safe(p_ent, tmp, &p_spq->completion_pending, list) {
                if (p_ent->elem.hdr.echo == echo) {
                        list_del(&p_ent->list);
                        qed_spq_comp_bmap_update(p_hwfn, echo);
                        p_spq->comp_count++;
                        found = p_ent;
                        break;
                }

                /* This is relatively uncommon - depends on scenarios
                 * which have mutliple per-PF sent ramrods.
                 */
                DP_VERBOSE(p_hwfn, QED_MSG_SPQ,
                           "Got completion for echo %04x - doesn't match echo %04x in completion pending list\n",
                           le16_to_cpu(echo),
                           le16_to_cpu(p_ent->elem.hdr.echo));
        }

        /* Release lock before callback, as callback may post
         * an additional ramrod.
         */
        spin_unlock_bh(&p_spq->lock);

        if (!found) {
                DP_NOTICE(p_hwfn,
                          "Failed to find an entry this EQE [echo %04x] completes\n",
                          le16_to_cpu(echo));
                return -EEXIST;
        }

        DP_VERBOSE(p_hwfn, QED_MSG_SPQ,
                   "Complete EQE [echo %04x]: func %p cookie %p)\n",
                   le16_to_cpu(echo),
                   p_ent->comp_cb.function, p_ent->comp_cb.cookie);
        if (found->comp_cb.function)
                found->comp_cb.function(p_hwfn, found->comp_cb.cookie, p_data,
                                        fw_return_code);
        else
                DP_VERBOSE(p_hwfn,
                           QED_MSG_SPQ,
                           "Got a completion without a callback function\n");

        if (found->comp_mode != QED_SPQ_MODE_EBLOCK)
                /* EBLOCK  is responsible for returning its own entry into the
                 * free list.
                 */
                qed_spq_return_entry(p_hwfn, found);

        return 0;
}

int qed_consq_alloc(struct qed_hwfn *p_hwfn)
{
        struct qed_consq *p_consq;

        /* Allocate ConsQ struct */
        p_consq = kzalloc(sizeof(*p_consq), GFP_KERNEL);
        if (!p_consq)
                return -ENOMEM;

        /* Allocate and initialize EQ chain*/
        if (qed_chain_alloc(p_hwfn->cdev,
                            QED_CHAIN_USE_TO_PRODUCE,
                            QED_CHAIN_MODE_PBL,
                            QED_CHAIN_CNT_TYPE_U16,
                            QED_CHAIN_PAGE_SIZE / 0x80,
                            0x80, &p_consq->chain, NULL))
                goto consq_allocate_fail;

        p_hwfn->p_consq = p_consq;
        return 0;

consq_allocate_fail:
        kfree(p_consq);
        return -ENOMEM;
}

void qed_consq_setup(struct qed_hwfn *p_hwfn)
{
        qed_chain_reset(&p_hwfn->p_consq->chain);
}

void qed_consq_free(struct qed_hwfn *p_hwfn)
{
        if (!p_hwfn->p_consq)
                return;

        qed_chain_free(p_hwfn->cdev, &p_hwfn->p_consq->chain);

        kfree(p_hwfn->p_consq);
        p_hwfn->p_consq = NULL;
}