/* Broadcom NetXtreme-C/E network driver.
 *
 * Copyright (c) 2020 Broadcom Limited
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation.
 */

#include <asm/byteorder.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/errno.h>
#include <linux/ethtool.h>
#include <linux/if_ether.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/netdevice.h>
#include <linux/pci.h>
#include <linux/skbuff.h>
#include <linux/bnxt/hsi.h>

#include "bnxt.h"
#include "bnxt_hwrm.h"

static u64 hwrm_calc_sentinel(struct bnxt_hwrm_ctx *ctx, u16 req_type)
{
        return (((uintptr_t)ctx) + req_type) ^ BNXT_HWRM_SENTINEL;
}

/**
 * __hwrm_req_init() - Initialize an HWRM request.
 * @bp: The driver context.
 * @req: A pointer to the request pointer to initialize.
 * @req_type: The request type. This will be converted to the little endian
 *      before being written to the req_type field of the returned request.
 * @req_len: The length of the request to be allocated.
 *
 * Allocate DMA resources and initialize a new HWRM request object of the
 * given type. The response address field in the request is configured with
 * the DMA bus address that has been mapped for the response and the passed
 * request is pointed to kernel virtual memory mapped for the request (such
 * that short_input indirection can be accomplished without copying). The
 * request’s target and completion ring are initialized to default values and
 * can be overridden by writing to the returned request object directly.
 *
 * The initialized request can be further customized by writing to its fields
 * directly, taking care to covert such fields to little endian. The request
 * object will be consumed (and all its associated resources release) upon
 * passing it to hwrm_req_send() unless ownership of the request has been
 * claimed by the caller via a call to hwrm_req_hold(). If the request is not
 * consumed, either because it is never sent or because ownership has been
 * claimed, then it must be released by a call to hwrm_req_drop().
 *
 * Return: zero on success, negative error code otherwise:
 *      E2BIG: the type of request pointer is too large to fit.
 *      ENOMEM: an allocation failure occurred.
 */
int __hwrm_req_init(struct bnxt *bp, void **req, u16 req_type, u32 req_len)
{
        struct bnxt_hwrm_ctx *ctx;
        dma_addr_t dma_handle;
        u8 *req_addr;

        if (req_len > BNXT_HWRM_CTX_OFFSET)
                return -E2BIG;

        req_addr = dma_pool_alloc(bp->hwrm_dma_pool, GFP_KERNEL | __GFP_ZERO,
                                  &dma_handle);
        if (!req_addr)
                return -ENOMEM;

        ctx = (struct bnxt_hwrm_ctx *)(req_addr + BNXT_HWRM_CTX_OFFSET);
        /* safety first, sentinel used to check for invalid requests */
        ctx->sentinel = hwrm_calc_sentinel(ctx, req_type);
        ctx->req_len = req_len;
        ctx->req = (struct input *)req_addr;
        ctx->resp = (struct output *)(req_addr + BNXT_HWRM_RESP_OFFSET);
        ctx->dma_handle = dma_handle;
        ctx->flags = 0; /* __GFP_ZERO, but be explicit regarding ownership */
        ctx->timeout = bp->hwrm_cmd_timeout ?: DFLT_HWRM_CMD_TIMEOUT;
        ctx->allocated = BNXT_HWRM_DMA_SIZE - BNXT_HWRM_CTX_OFFSET;
        ctx->gfp = GFP_KERNEL;
        ctx->slice_addr = NULL;

        /* initialize common request fields */
        ctx->req->req_type = cpu_to_le16(req_type);
        ctx->req->resp_addr = cpu_to_le64(dma_handle + BNXT_HWRM_RESP_OFFSET);
        ctx->req->cmpl_ring = cpu_to_le16(BNXT_HWRM_NO_CMPL_RING);
        ctx->req->target_id = cpu_to_le16(BNXT_HWRM_TARGET);
        *req = ctx->req;

        return 0;
}

static struct bnxt_hwrm_ctx *__hwrm_ctx(struct bnxt *bp, u8 *req_addr)
{
        void *ctx_addr = req_addr + BNXT_HWRM_CTX_OFFSET;
        struct input *req = (struct input *)req_addr;
        struct bnxt_hwrm_ctx *ctx = ctx_addr;
        u64 sentinel;

        if (!req) {
                /* can only be due to software bug, be loud */
                netdev_err(bp->dev, "null HWRM request");
                dump_stack();
                return NULL;
        }

        /* HWRM API has no type safety, verify sentinel to validate address */
        sentinel = hwrm_calc_sentinel(ctx, le16_to_cpu(req->req_type));
        if (ctx->sentinel != sentinel) {
                /* can only be due to software bug, be loud */
                netdev_err(bp->dev, "HWRM sentinel mismatch, req_type = %u\n",
                           (u32)le16_to_cpu(req->req_type));
                dump_stack();
                return NULL;
        }

        return ctx;
}

/**
 * hwrm_req_timeout() - Set the completion timeout for the request.
 * @bp: The driver context.
 * @req: The request to set the timeout.
 * @timeout: The timeout in milliseconds.
 *
 * Set the timeout associated with the request for subsequent calls to
 * hwrm_req_send(). Some requests are long running and require a different
 * timeout than the default.
 */
void hwrm_req_timeout(struct bnxt *bp, void *req, unsigned int timeout)
{
        struct bnxt_hwrm_ctx *ctx = __hwrm_ctx(bp, req);

        if (ctx)
                ctx->timeout = timeout;
}

/**
 * hwrm_req_alloc_flags() - Sets GFP allocation flags for slices.
 * @bp: The driver context.
 * @req: The request for which calls to hwrm_req_dma_slice() will have altered
 *      allocation flags.
 * @gfp: A bitmask of GFP flags. These flags are passed to dma_alloc_coherent()
 *      whenever it is used to allocate backing memory for slices. Note that
 *      calls to hwrm_req_dma_slice() will not always result in new allocations,
 *      however, memory suballocated from the request buffer is already
 *      __GFP_ZERO.
 *
 * Sets the GFP allocation flags associated with the request for subsequent
 * calls to hwrm_req_dma_slice(). This can be useful for specifying __GFP_ZERO
 * for slice allocations.
 */
void hwrm_req_alloc_flags(struct bnxt *bp, void *req, gfp_t gfp)
{
        struct bnxt_hwrm_ctx *ctx = __hwrm_ctx(bp, req);

        if (ctx)
                ctx->gfp = gfp;
}

/**
 * hwrm_req_replace() - Replace request data.
 * @bp: The driver context.
 * @req: The request to modify. A call to hwrm_req_replace() is conceptually
 *      an assignment of new_req to req. Subsequent calls to HWRM API functions,
 *      such as hwrm_req_send(), should thus use req and not new_req (in fact,
 *      calls to HWRM API functions will fail if non-managed request objects
 *      are passed).
 * @len: The length of new_req.
 * @new_req: The pre-built request to copy or reference.
 *
 * Replaces the request data in req with that of new_req. This is useful in
 * scenarios where a request object has already been constructed by a third
 * party prior to creating a resource managed request using hwrm_req_init().
 * Depending on the length, hwrm_req_replace() will either copy the new
 * request data into the DMA memory allocated for req, or it will simply
 * reference the new request and use it in lieu of req during subsequent
 * calls to hwrm_req_send(). The resource management is associated with
 * req and is independent of and does not apply to new_req. The caller must
 * ensure that the lifetime of new_req is least as long as req. Any slices
 * that may have been associated with the original request are released.
 *
 * Return: zero on success, negative error code otherwise:
 *     E2BIG: Request is too large.
 *     EINVAL: Invalid request to modify.
 */
int hwrm_req_replace(struct bnxt *bp, void *req, void *new_req, u32 len)
{
        struct bnxt_hwrm_ctx *ctx = __hwrm_ctx(bp, req);
        struct input *internal_req = req;
        u16 req_type;

        if (!ctx)
                return -EINVAL;

        if (len > BNXT_HWRM_CTX_OFFSET)
                return -E2BIG;

        /* free any existing slices */
        ctx->allocated = BNXT_HWRM_DMA_SIZE - BNXT_HWRM_CTX_OFFSET;
        if (ctx->slice_addr) {
                dma_free_coherent(&bp->pdev->dev, ctx->slice_size,
                                  ctx->slice_addr, ctx->slice_handle);
                ctx->slice_addr = NULL;
        }
        ctx->gfp = GFP_KERNEL;

        if ((bp->fw_cap & BNXT_FW_CAP_SHORT_CMD) || len > BNXT_HWRM_MAX_REQ_LEN) {
                memcpy(internal_req, new_req, len);
        } else {
                internal_req->req_type = ((struct input *)new_req)->req_type;
                ctx->req = new_req;
        }

        ctx->req_len = len;
        ctx->req->resp_addr = cpu_to_le64(ctx->dma_handle +
                                          BNXT_HWRM_RESP_OFFSET);

        /* update sentinel for potentially new request type */
        req_type = le16_to_cpu(internal_req->req_type);
        ctx->sentinel = hwrm_calc_sentinel(ctx, req_type);

        return 0;
}

/**
 * hwrm_req_flags() - Set non internal flags of the ctx
 * @bp: The driver context.
 * @req: The request containing the HWRM command
 * @flags: ctx flags that don't have BNXT_HWRM_INTERNAL_FLAG set
 *
 * ctx flags can be used by the callers to instruct how the subsequent
 * hwrm_req_send() should behave. Example: callers can use hwrm_req_flags
 * with BNXT_HWRM_CTX_SILENT to omit kernel prints of errors of hwrm_req_send()
 * or with BNXT_HWRM_FULL_WAIT enforce hwrm_req_send() to wait for full timeout
 * even if FW is not responding.
 * This generic function can be used to set any flag that is not an internal flag
 * of the HWRM module.
 */
void hwrm_req_flags(struct bnxt *bp, void *req, enum bnxt_hwrm_ctx_flags flags)
{
        struct bnxt_hwrm_ctx *ctx = __hwrm_ctx(bp, req);

        if (ctx)
                ctx->flags |= (flags & HWRM_API_FLAGS);
}

/**
 * hwrm_req_hold() - Claim ownership of the request's resources.
 * @bp: The driver context.
 * @req: A pointer to the request to own. The request will no longer be
 *      consumed by calls to hwrm_req_send().
 *
 * Take ownership of the request. Ownership places responsibility on the
 * caller to free the resources associated with the request via a call to
 * hwrm_req_drop(). The caller taking ownership implies that a subsequent
 * call to hwrm_req_send() will not consume the request (ie. sending will
 * not free the associated resources if the request is owned by the caller).
 * Taking ownership returns a reference to the response. Retaining and
 * accessing the response data is the most common reason to take ownership
 * of the request. Ownership can also be acquired in order to reuse the same
 * request object across multiple invocations of hwrm_req_send().
 *
 * Return: A pointer to the response object.
 *
 * The resources associated with the response will remain available to the
 * caller until ownership of the request is relinquished via a call to
 * hwrm_req_drop(). It is not possible for hwrm_req_hold() to return NULL if
 * a valid request is provided. A returned NULL value would imply a driver
 * bug and the implementation will complain loudly in the logs to aid in
 * detection. It should not be necessary to check the result for NULL.
 */
void *hwrm_req_hold(struct bnxt *bp, void *req)
{
        struct bnxt_hwrm_ctx *ctx = __hwrm_ctx(bp, req);
        struct input *input = (struct input *)req;

        if (!ctx)
                return NULL;

        if (ctx->flags & BNXT_HWRM_INTERNAL_CTX_OWNED) {
                /* can only be due to software bug, be loud */
                netdev_err(bp->dev, "HWRM context already owned, req_type = %u\n",
                           (u32)le16_to_cpu(input->req_type));
                dump_stack();
                return NULL;
        }

        ctx->flags |= BNXT_HWRM_INTERNAL_CTX_OWNED;
        return ((u8 *)req) + BNXT_HWRM_RESP_OFFSET;
}

static void __hwrm_ctx_drop(struct bnxt *bp, struct bnxt_hwrm_ctx *ctx)
{
        void *addr = ((u8 *)ctx) - BNXT_HWRM_CTX_OFFSET;
        dma_addr_t dma_handle = ctx->dma_handle; /* save before invalidate */

        /* unmap any auxiliary DMA slice */
        if (ctx->slice_addr)
                dma_free_coherent(&bp->pdev->dev, ctx->slice_size,
                                  ctx->slice_addr, ctx->slice_handle);

        /* invalidate, ensure ownership, sentinel and dma_handle are cleared */
        memset(ctx, 0, sizeof(struct bnxt_hwrm_ctx));

        /* return the buffer to the DMA pool */
        if (dma_handle)
                dma_pool_free(bp->hwrm_dma_pool, addr, dma_handle);
}

/**
 * hwrm_req_drop() - Release all resources associated with the request.
 * @bp: The driver context.
 * @req: The request to consume, releasing the associated resources. The
 *      request object, any slices, and its associated response are no
 *      longer valid.
 *
 * It is legal to call hwrm_req_drop() on an unowned request, provided it
 * has not already been consumed by hwrm_req_send() (for example, to release
 * an aborted request). A given request should not be dropped more than once,
 * nor should it be dropped after having been consumed by hwrm_req_send(). To
 * do so is an error (the context will not be found and a stack trace will be
 * rendered in the kernel log).
 */
void hwrm_req_drop(struct bnxt *bp, void *req)
{
        struct bnxt_hwrm_ctx *ctx = __hwrm_ctx(bp, req);

        if (ctx)
                __hwrm_ctx_drop(bp, ctx);
}

static int __hwrm_to_stderr(u32 hwrm_err)
{
        switch (hwrm_err) {
        case HWRM_ERR_CODE_SUCCESS:
                return 0;
        case HWRM_ERR_CODE_RESOURCE_LOCKED:
                return -EROFS;
        case HWRM_ERR_CODE_RESOURCE_ACCESS_DENIED:
                return -EACCES;
        case HWRM_ERR_CODE_RESOURCE_ALLOC_ERROR:
                return -ENOSPC;
        case HWRM_ERR_CODE_INVALID_PARAMS:
        case HWRM_ERR_CODE_INVALID_FLAGS:
        case HWRM_ERR_CODE_INVALID_ENABLES:
        case HWRM_ERR_CODE_UNSUPPORTED_TLV:
        case HWRM_ERR_CODE_UNSUPPORTED_OPTION_ERR:
                return -EINVAL;
        case HWRM_ERR_CODE_NO_BUFFER:
                return -ENOMEM;
        case HWRM_ERR_CODE_HOT_RESET_PROGRESS:
        case HWRM_ERR_CODE_BUSY:
                return -EAGAIN;
        case HWRM_ERR_CODE_CMD_NOT_SUPPORTED:
                return -EOPNOTSUPP;
        case HWRM_ERR_CODE_PF_UNAVAILABLE:
                return -ENODEV;
        default:
                return -EIO;
        }
}

static struct bnxt_hwrm_wait_token *
__hwrm_acquire_token(struct bnxt *bp, enum bnxt_hwrm_chnl dst)
{
        struct bnxt_hwrm_wait_token *token;

        token = kzalloc_obj(*token);
        if (!token)
                return NULL;

        mutex_lock(&bp->hwrm_cmd_lock);

        token->dst = dst;
        token->state = BNXT_HWRM_PENDING;
        if (dst == BNXT_HWRM_CHNL_CHIMP) {
                token->seq_id = bp->hwrm_cmd_seq++;
                hlist_add_head_rcu(&token->node, &bp->hwrm_pending_list);
        } else {
                token->seq_id = bp->hwrm_cmd_kong_seq++;
        }

        return token;
}

static void
__hwrm_release_token(struct bnxt *bp, struct bnxt_hwrm_wait_token *token)
{
        if (token->dst == BNXT_HWRM_CHNL_CHIMP) {
                hlist_del_rcu(&token->node);
                kfree_rcu(token, rcu);
        } else {
                kfree(token);
        }
        mutex_unlock(&bp->hwrm_cmd_lock);
}

void
hwrm_update_token(struct bnxt *bp, u16 seq_id, enum bnxt_hwrm_wait_state state)
{
        struct bnxt_hwrm_wait_token *token;

        rcu_read_lock();
        hlist_for_each_entry_rcu(token, &bp->hwrm_pending_list, node) {
                if (token->seq_id == seq_id) {
                        WRITE_ONCE(token->state, state);
                        rcu_read_unlock();
                        return;
                }
        }
        rcu_read_unlock();
        netdev_err(bp->dev, "Invalid hwrm seq id %d\n", seq_id);
}

static void hwrm_req_dbg(struct bnxt *bp, struct input *req)
{
        u32 ring = le16_to_cpu(req->cmpl_ring);
        u32 type = le16_to_cpu(req->req_type);
        u32 tgt = le16_to_cpu(req->target_id);
        u32 seq = le16_to_cpu(req->seq_id);
        char opt[32] = "\n";

        if (unlikely(ring != (u16)BNXT_HWRM_NO_CMPL_RING))
                snprintf(opt, 16, " ring %d\n", ring);

        if (unlikely(tgt != BNXT_HWRM_TARGET))
                snprintf(opt + strlen(opt) - 1, 16, " tgt 0x%x\n", tgt);

        netdev_dbg(bp->dev, "sent hwrm req_type 0x%x seq id 0x%x%s",
                   type, seq, opt);
}

#define hwrm_err(bp, ctx, fmt, ...)                                    \
        do {                                                           \
                if ((ctx)->flags & BNXT_HWRM_CTX_SILENT)               \
                        netdev_dbg((bp)->dev, fmt, __VA_ARGS__);       \
                else                                                   \
                        netdev_err((bp)->dev, fmt, __VA_ARGS__);       \
        } while (0)

static bool hwrm_wait_must_abort(struct bnxt *bp, u32 req_type, u32 *fw_status)
{
        if (req_type == HWRM_VER_GET)
                return false;

        if (!bp->fw_health || !bp->fw_health->status_reliable)
                return false;

        *fw_status = bnxt_fw_health_readl(bp, BNXT_FW_HEALTH_REG);
        return *fw_status && !BNXT_FW_IS_HEALTHY(*fw_status);
}

static int __hwrm_send(struct bnxt *bp, struct bnxt_hwrm_ctx *ctx)
{
        u32 doorbell_offset = BNXT_GRCPF_REG_CHIMP_COMM_TRIGGER;
        enum bnxt_hwrm_chnl dst = BNXT_HWRM_CHNL_CHIMP;
        u32 bar_offset = BNXT_GRCPF_REG_CHIMP_COMM;
        struct bnxt_hwrm_wait_token *token = NULL;
        struct hwrm_short_input short_input = {0};
        u16 max_req_len = BNXT_HWRM_MAX_REQ_LEN;
        unsigned int i, timeout, tmo_count;
        u32 *data = (u32 *)ctx->req;
        u32 msg_len = ctx->req_len;
        u32 req_type, sts;
        int rc = -EBUSY;
        u16 len = 0;
        u8 *valid;

        if (ctx->flags & BNXT_HWRM_INTERNAL_RESP_DIRTY)
                memset(ctx->resp, 0, PAGE_SIZE);

        req_type = le16_to_cpu(ctx->req->req_type);
        if (BNXT_NO_FW_ACCESS(bp) &&
            (req_type != HWRM_FUNC_RESET && req_type != HWRM_VER_GET)) {
                netdev_dbg(bp->dev, "hwrm req_type 0x%x skipped, FW channel down\n",
                           req_type);
                goto exit;
        }

        if (msg_len > BNXT_HWRM_MAX_REQ_LEN &&
            msg_len > bp->hwrm_max_ext_req_len) {
                netdev_warn(bp->dev, "oversized hwrm request, req_type 0x%x",
                            req_type);
                rc = -E2BIG;
                goto exit;
        }

        if (bnxt_kong_hwrm_message(bp, ctx->req)) {
                dst = BNXT_HWRM_CHNL_KONG;
                bar_offset = BNXT_GRCPF_REG_KONG_COMM;
                doorbell_offset = BNXT_GRCPF_REG_KONG_COMM_TRIGGER;
                if (le16_to_cpu(ctx->req->cmpl_ring) != INVALID_HW_RING_ID) {
                        netdev_err(bp->dev, "Ring completions not supported for KONG commands, req_type = %d\n",
                                   req_type);
                        rc = -EINVAL;
                        goto exit;
                }
        }

        token = __hwrm_acquire_token(bp, dst);
        if (!token) {
                rc = -ENOMEM;
                goto exit;
        }
        ctx->req->seq_id = cpu_to_le16(token->seq_id);

        if ((bp->fw_cap & BNXT_FW_CAP_SHORT_CMD) ||
            msg_len > BNXT_HWRM_MAX_REQ_LEN) {
                short_input.req_type = ctx->req->req_type;
                short_input.signature =
                                cpu_to_le16(SHORT_REQ_SIGNATURE_SHORT_CMD);
                short_input.size = cpu_to_le16(msg_len);
                short_input.req_addr = cpu_to_le64(ctx->dma_handle);

                data = (u32 *)&short_input;
                msg_len = sizeof(short_input);

                max_req_len = BNXT_HWRM_SHORT_REQ_LEN;
        }

        /* Ensure any associated DMA buffers are written before doorbell */
        wmb();

        /* Write request msg to hwrm channel */
        __iowrite32_copy(bp->bar0 + bar_offset, data, msg_len / 4);

        for (i = msg_len; i < max_req_len; i += 4)
                writel(0, bp->bar0 + bar_offset + i);

        /* Ring channel doorbell */
        writel(1, bp->bar0 + doorbell_offset);

        hwrm_req_dbg(bp, ctx->req);

        if (!pci_is_enabled(bp->pdev)) {
                rc = -ENODEV;
                goto exit;
        }

        /* Limit timeout to an upper limit */
        timeout = min(ctx->timeout, bp->hwrm_cmd_max_timeout ?: HWRM_CMD_MAX_TIMEOUT);
        /* convert timeout to usec */
        timeout *= 1000;

        i = 0;
        /* Short timeout for the first few iterations:
         * number of loops = number of loops for short timeout +
         * number of loops for standard timeout.
         */
        tmo_count = HWRM_SHORT_TIMEOUT_COUNTER;
        timeout = timeout - HWRM_SHORT_MIN_TIMEOUT * HWRM_SHORT_TIMEOUT_COUNTER;
        tmo_count += DIV_ROUND_UP(timeout, HWRM_MIN_TIMEOUT);

        if (le16_to_cpu(ctx->req->cmpl_ring) != INVALID_HW_RING_ID) {
                /* Wait until hwrm response cmpl interrupt is processed */
                while (READ_ONCE(token->state) < BNXT_HWRM_COMPLETE &&
                       i++ < tmo_count) {
                        /* Abort the wait for completion if the FW health
                         * check has failed.
                         */
                        if (test_bit(BNXT_STATE_FW_FATAL_COND, &bp->state))
                                goto exit;
                        /* on first few passes, just barely sleep */
                        if (i < HWRM_SHORT_TIMEOUT_COUNTER) {
                                usleep_range(HWRM_SHORT_MIN_TIMEOUT,
                                             HWRM_SHORT_MAX_TIMEOUT);
                        } else {
                                if (hwrm_wait_must_abort(bp, req_type, &sts)) {
                                        hwrm_err(bp, ctx, "Resp cmpl intr abandoning msg: 0x%x due to firmware status: 0x%x\n",
                                                 req_type, sts);
                                        goto exit;
                                }
                                usleep_range(HWRM_MIN_TIMEOUT,
                                             HWRM_MAX_TIMEOUT);
                        }
                }

                if (READ_ONCE(token->state) != BNXT_HWRM_COMPLETE) {
                        hwrm_err(bp, ctx, "Resp cmpl intr err msg: 0x%x\n",
                                 req_type);
                        goto exit;
                }
                len = le16_to_cpu(READ_ONCE(ctx->resp->resp_len));
                valid = ((u8 *)ctx->resp) + len - 1;
        } else {
                __le16 seen_out_of_seq = ctx->req->seq_id; /* will never see */
                int j;

                /* Check if response len is updated */
                for (i = 0; i < tmo_count; i++) {
                        /* Abort the wait for completion if the FW health
                         * check has failed.
                         */
                        if (test_bit(BNXT_STATE_FW_FATAL_COND, &bp->state))
                                goto exit;

                        if (token &&
                            READ_ONCE(token->state) == BNXT_HWRM_DEFERRED) {
                                __hwrm_release_token(bp, token);
                                token = NULL;
                        }

                        len = le16_to_cpu(READ_ONCE(ctx->resp->resp_len));
                        if (len) {
                                __le16 resp_seq = READ_ONCE(ctx->resp->seq_id);

                                if (resp_seq == ctx->req->seq_id)
                                        break;
                                if (resp_seq != seen_out_of_seq) {
                                        netdev_warn(bp->dev, "Discarding out of seq response: 0x%x for msg {0x%x 0x%x}\n",
                                                    le16_to_cpu(resp_seq),
                                                    req_type,
                                                    le16_to_cpu(ctx->req->seq_id));
                                        seen_out_of_seq = resp_seq;
                                }
                        }

                        /* on first few passes, just barely sleep */
                        if (i < HWRM_SHORT_TIMEOUT_COUNTER) {
                                usleep_range(HWRM_SHORT_MIN_TIMEOUT,
                                             HWRM_SHORT_MAX_TIMEOUT);
                        } else {
                                if (hwrm_wait_must_abort(bp, req_type, &sts)) {
                                        hwrm_err(bp, ctx, "Abandoning msg {0x%x 0x%x} len: %d due to firmware status: 0x%x\n",
                                                 req_type,
                                                 le16_to_cpu(ctx->req->seq_id),
                                                 len, sts);
                                        goto exit;
                                }
                                usleep_range(HWRM_MIN_TIMEOUT,
                                             HWRM_MAX_TIMEOUT);
                        }
                }

                if (i >= tmo_count) {
                        hwrm_err(bp, ctx, "Error (timeout: %u) msg {0x%x 0x%x} len:%d\n",
                                 hwrm_total_timeout(i), req_type,
                                 le16_to_cpu(ctx->req->seq_id), len);
                        goto exit;
                }

                /* Last byte of resp contains valid bit */
                valid = ((u8 *)ctx->resp) + len - 1;
                for (j = 0; j < HWRM_VALID_BIT_DELAY_USEC; ) {
                        /* make sure we read from updated DMA memory */
                        dma_rmb();
                        if (*valid)
                                break;
                        if (j < 10) {
                                udelay(1);
                                j++;
                        } else {
                                usleep_range(20, 30);
                                j += 20;
                        }
                }

                if (j >= HWRM_VALID_BIT_DELAY_USEC) {
                        hwrm_err(bp, ctx, "Error (timeout: %u) msg {0x%x 0x%x} len:%d v:%d\n",
                                 hwrm_total_timeout(i) + j, req_type,
                                 le16_to_cpu(ctx->req->seq_id), len, *valid);
                        goto exit;
                }
        }

        /* Zero valid bit for compatibility.  Valid bit in an older spec
         * may become a new field in a newer spec.  We must make sure that
         * a new field not implemented by old spec will read zero.
         */
        *valid = 0;
        rc = le16_to_cpu(ctx->resp->error_code);
        if (rc == HWRM_ERR_CODE_BUSY && !(ctx->flags & BNXT_HWRM_CTX_SILENT))
                netdev_warn(bp->dev, "FW returned busy, hwrm req_type 0x%x\n",
                            req_type);
        else if (rc && rc != HWRM_ERR_CODE_PF_UNAVAILABLE)
                hwrm_err(bp, ctx, "hwrm req_type 0x%x seq id 0x%x error 0x%x\n",
                         req_type, le16_to_cpu(ctx->req->seq_id), rc);
        rc = __hwrm_to_stderr(rc);
exit:
        if (token)
                __hwrm_release_token(bp, token);
        if (ctx->flags & BNXT_HWRM_INTERNAL_CTX_OWNED)
                ctx->flags |= BNXT_HWRM_INTERNAL_RESP_DIRTY;
        else
                __hwrm_ctx_drop(bp, ctx);
        return rc;
}

/**
 * hwrm_req_send() - Execute an HWRM command.
 * @bp: The driver context.
 * @req: A pointer to the request to send. The DMA resources associated with
 *      the request will be released (ie. the request will be consumed) unless
 *      ownership of the request has been assumed by the caller via a call to
 *      hwrm_req_hold().
 *
 * Send an HWRM request to the device and wait for a response. The request is
 * consumed if it is not owned by the caller. This function will block until
 * the request has either completed or times out due to an error.
 *
 * Return: A result code.
 *
 * The result is zero on success, otherwise the negative error code indicates
 * one of the following errors:
 *      E2BIG: The request was too large.
 *      EBUSY: The firmware is in a fatal state or the request timed out
 *      EACCESS: HWRM access denied.
 *      ENOSPC: HWRM resource allocation error.
 *      EINVAL: Request parameters are invalid.
 *      ENOMEM: HWRM has no buffers.
 *      EAGAIN: HWRM busy or reset in progress.
 *      EOPNOTSUPP: Invalid request type.
 *      EIO: Any other error.
 * Error handling is orthogonal to request ownership. An unowned request will
 * still be consumed on error. If the caller owns the request, then the caller
 * is responsible for releasing the resources. Otherwise, hwrm_req_send() will
 * always consume the request.
 */
int hwrm_req_send(struct bnxt *bp, void *req)
{
        struct bnxt_hwrm_ctx *ctx = __hwrm_ctx(bp, req);

        if (!ctx)
                return -EINVAL;

        return __hwrm_send(bp, ctx);
}

/**
 * hwrm_req_send_silent() - A silent version of hwrm_req_send().
 * @bp: The driver context.
 * @req: The request to send without logging.
 *
 * The same as hwrm_req_send(), except that the request is silenced using
 * hwrm_req_silence() prior the call. This version of the function is
 * provided solely to preserve the legacy API’s flavor for this functionality.
 *
 * Return: A result code, see hwrm_req_send().
 */
int hwrm_req_send_silent(struct bnxt *bp, void *req)
{
        hwrm_req_flags(bp, req, BNXT_HWRM_CTX_SILENT);
        return hwrm_req_send(bp, req);
}

/**
 * hwrm_req_dma_slice() - Allocate a slice of DMA mapped memory.
 * @bp: The driver context.
 * @req: The request for which indirect data will be associated.
 * @size: The size of the allocation.
 * @dma_handle: The bus address associated with the allocation. The HWRM API has
 *      no knowledge about the type of the request and so cannot infer how the
 *      caller intends to use the indirect data. Thus, the caller is
 *      responsible for configuring the request object appropriately to
 *      point to the associated indirect memory. Note, DMA handle has the
 *      same definition as it does in dma_alloc_coherent(), the caller is
 *      responsible for endian conversions via cpu_to_le64() before assigning
 *      this address.
 *
 * Allocates DMA mapped memory for indirect data related to a request. The
 * lifetime of the DMA resources will be bound to that of the request (ie.
 * they will be automatically released when the request is either consumed by
 * hwrm_req_send() or dropped by hwrm_req_drop()). Small allocations are
 * efficiently suballocated out of the request buffer space, hence the name
 * slice, while larger requests are satisfied via an underlying call to
 * dma_alloc_coherent(). Multiple suballocations are supported, however, only
 * one externally mapped region is.
 *
 * Return: The kernel virtual address of the DMA mapping.
 */
void *
hwrm_req_dma_slice(struct bnxt *bp, void *req, u32 size, dma_addr_t *dma_handle)
{
        struct bnxt_hwrm_ctx *ctx = __hwrm_ctx(bp, req);
        u8 *end = ((u8 *)req) + BNXT_HWRM_DMA_SIZE;
        struct input *input = req;
        u8 *addr, *req_addr = req;
        u32 max_offset, offset;

        if (!ctx)
                return NULL;

        max_offset = BNXT_HWRM_DMA_SIZE - ctx->allocated;
        offset = max_offset - size;
        offset = ALIGN_DOWN(offset, BNXT_HWRM_DMA_ALIGN);
        addr = req_addr + offset;

        if (addr < req_addr + max_offset && req_addr + ctx->req_len <= addr) {
                ctx->allocated = end - addr;
                *dma_handle = ctx->dma_handle + offset;
                return addr;
        }

        /* could not suballocate from ctx buffer, try create a new mapping */
        if (ctx->slice_addr) {
                /* if one exists, can only be due to software bug, be loud */
                netdev_err(bp->dev, "HWRM refusing to reallocate DMA slice, req_type = %u\n",
                           (u32)le16_to_cpu(input->req_type));
                dump_stack();
                return NULL;
        }

        addr = dma_alloc_coherent(&bp->pdev->dev, size, dma_handle, ctx->gfp);

        if (!addr)
                return NULL;

        ctx->slice_addr = addr;
        ctx->slice_size = size;
        ctx->slice_handle = *dma_handle;

        return addr;
}