Re: [PATCH v3 19/31] elx: efct: Hardware IO and SGL initialization

[Daniel Wagner <dwagner@suse.de>]

On Sat, Apr 11, 2020 at 08:32:51PM -0700, James Smart wrote:
> This patch continues the efct driver population.
> 
> This patch adds driver definitions for:
> Routines to create IO interfaces (wqs, etc), SGL initialization,
> and configure hardware features.
> 
> Signed-off-by: Ram Vegesna <ram.vegesna@broadcom.com>
> Signed-off-by: James Smart <jsmart2021@gmail.com>
> 
> ---
> v3:
>   Request tag pool(reqtag_pool) handling fuctions.
> ---
>  drivers/scsi/elx/efct/efct_hw.c | 657 ++++++++++++++++++++++++++++++++++++++++
>  drivers/scsi/elx/efct/efct_hw.h |  42 +++
>  2 files changed, 699 insertions(+)
> 
> diff --git a/drivers/scsi/elx/efct/efct_hw.c b/drivers/scsi/elx/efct/efct_hw.c
> index 3e9906749da2..892493a3a35e 100644
> --- a/drivers/scsi/elx/efct/efct_hw.c
> +++ b/drivers/scsi/elx/efct/efct_hw.c
> @@ -1489,3 +1489,660 @@ efct_hw_command_cancel(struct efct_hw *hw)
>  
>  	return EFC_SUCCESS;
>  }
> +
> +static inline struct efct_hw_io *
> +_efct_hw_io_alloc(struct efct_hw *hw)
> +{
> +	struct efct_hw_io	*io = NULL;
> +
> +	if (!list_empty(&hw->io_free)) {
> +		io = list_first_entry(&hw->io_free, struct efct_hw_io,
> +				      list_entry);
> +		list_del(&io->list_entry);
> +	}
> +	if (io) {
> +		INIT_LIST_HEAD(&io->list_entry);
> +		INIT_LIST_HEAD(&io->wqe_link);
> +		INIT_LIST_HEAD(&io->dnrx_link);
> +		list_add_tail(&io->list_entry, &hw->io_inuse);
> +		io->state = EFCT_HW_IO_STATE_INUSE;
> +		io->abort_reqtag = U32_MAX;
> +		io->wq = hw->hw_wq[0];
> +		kref_init(&io->ref);
> +		io->release = efct_hw_io_free_internal;
> +	} else {
> +		atomic_add_return(1, &hw->io_alloc_failed_count);
> +	}
> +
> +	return io;
> +}
> +
> +struct efct_hw_io *
> +efct_hw_io_alloc(struct efct_hw *hw)
> +{
> +	struct efct_hw_io	*io = NULL;
> +	unsigned long flags = 0;
> +
> +	spin_lock_irqsave(&hw->io_lock, flags);
> +	io = _efct_hw_io_alloc(hw);
> +	spin_unlock_irqrestore(&hw->io_lock, flags);
> +
> +	return io;
> +}
> +
> +/*
> + * When an IO is freed, depending on the exchange busy flag, and other
> + * workarounds, move it to the correct list.
> + */

kerneldoc

> +static void
> +efct_hw_io_free_move_correct_list(struct efct_hw *hw,
> +				  struct efct_hw_io *io)
> +{
> +	if (io->xbusy) {
> +		/*
> +		 * add to wait_free list and wait for XRI_ABORTED CQEs to clean
> +		 * up
> +		 */
> +		INIT_LIST_HEAD(&io->list_entry);
> +		list_add_tail(&io->list_entry, &hw->io_wait_free);
> +		io->state = EFCT_HW_IO_STATE_WAIT_FREE;
> +	} else {
> +		/* IO not busy, add to free list */
> +		INIT_LIST_HEAD(&io->list_entry);
> +		list_add_tail(&io->list_entry, &hw->io_free);
> +		io->state = EFCT_HW_IO_STATE_FREE;
> +	}
> +}
> +
> +static inline void
> +efct_hw_io_free_common(struct efct_hw *hw, struct efct_hw_io *io)
> +{
> +	/* initialize IO fields */
> +	efct_hw_init_free_io(io);
> +
> +	/* Restore default SGL */
> +	efct_hw_io_restore_sgl(hw, io);
> +}
> +
> +/**
> + * Free a previously-allocated HW IO object. Called when
> + * IO refcount goes to zero (host-owned IOs only).
> + */
> +void
> +efct_hw_io_free_internal(struct kref *arg)
> +{
> +	unsigned long flags = 0;
> +	struct efct_hw_io *io =
> +			container_of(arg, struct efct_hw_io, ref);

This fits on one line.

> +	struct efct_hw *hw = io->hw;
> +
> +	/* perform common cleanup */
> +	efct_hw_io_free_common(hw, io);
> +
> +	spin_lock_irqsave(&hw->io_lock, flags);
> +		/* remove from in-use list */
> +		if (io->list_entry.next &&
> +		    !list_empty(&hw->io_inuse)) {
> +			list_del(&io->list_entry);
> +			efct_hw_io_free_move_correct_list(hw, io);
> +		}

This doesn need to be extra indendent and the if condition fits on one
line.

> +	spin_unlock_irqrestore(&hw->io_lock, flags);
> +}
> +
> +int
> +efct_hw_io_free(struct efct_hw *hw, struct efct_hw_io *io)
> +{
> +	return kref_put(&io->ref, io->release);
> +}
> +
> +u8
> +efct_hw_io_inuse(struct efct_hw *hw, struct efct_hw_io *io)
> +{
> +	return (refcount_read(&io->ref.refcount) > 0);
> +}
> +
> +struct efct_hw_io *
> +efct_hw_io_lookup(struct efct_hw *hw, u32 xri)
> +{
> +	u32 ioindex;
> +
> +	ioindex = xri - hw->sli.extent[SLI_RSRC_XRI].base[0];
> +	return hw->io[ioindex];
> +}
> +
> +enum efct_hw_rtn
> +efct_hw_io_register_sgl(struct efct_hw *hw, struct efct_hw_io *io,
> +			struct efc_dma *sgl,
> +			u32 sgl_count)
> +{
> +	if (hw->sli.sgl_pre_registered) {
> +		efc_log_err(hw->os,
> +			     "can't use temp SGL with pre-registered SGLs\n");
> +		return EFCT_HW_RTN_ERROR;
> +	}
> +	io->ovfl_sgl = sgl;
> +	io->ovfl_sgl_count = sgl_count;
> +
> +	return EFCT_HW_RTN_SUCCESS;
> +}
> +
> +enum efct_hw_rtn
> +efct_hw_io_init_sges(struct efct_hw *hw, struct efct_hw_io *io,
> +		     enum efct_hw_io_type type)
> +{
> +	struct sli4_sge	*data = NULL;
> +	u32 i = 0;
> +	u32 skips = 0;
> +	u32 sge_flags = 0;
> +
> +	if (!io) {
> +		efc_log_err(hw->os,
> +			     "bad parameter hw=%p io=%p\n", hw, io);
> +		return EFCT_HW_RTN_ERROR;
> +	}
> +
> +	/* Clear / reset the scatter-gather list */
> +	io->sgl = &io->def_sgl;
> +	io->sgl_count = io->def_sgl_count;
> +	io->first_data_sge = 0;
> +
> +	memset(io->sgl->virt, 0, 2 * sizeof(struct sli4_sge));
> +	io->n_sge = 0;
> +	io->sge_offset = 0;
> +
> +	io->type = type;
> +
> +	data = io->sgl->virt;
> +
> +	/*
> +	 * Some IO types have underlying hardware requirements on the order
> +	 * of SGEs. Process all special entries here.
> +	 */
> +	switch (type) {
> +	case EFCT_HW_IO_TARGET_WRITE:
> +#define EFCT_TARGET_WRITE_SKIPS	2
> +		skips = EFCT_TARGET_WRITE_SKIPS;

Move the defines out of the function.


> +
> +		/* populate host resident XFER_RDY buffer */
> +		sge_flags = le32_to_cpu(data->dw2_flags);
> +		sge_flags &= (~SLI4_SGE_TYPE_MASK);
> +		sge_flags |= (SLI4_SGE_TYPE_DATA << SLI4_SGE_TYPE_SHIFT);
> +		data->buffer_address_high =
> +			cpu_to_le32(upper_32_bits(io->xfer_rdy.phys));
> +		data->buffer_address_low  =
> +			cpu_to_le32(lower_32_bits(io->xfer_rdy.phys));
> +		data->buffer_length = cpu_to_le32(io->xfer_rdy.size);
> +		data->dw2_flags = cpu_to_le32(sge_flags);
> +		data++;
> +
> +		skips--;
> +
> +		io->n_sge = 1;
> +		break;
> +	case EFCT_HW_IO_TARGET_READ:
> +		/*
> +		 * For FCP_TSEND64, the first 2 entries are SKIP SGE's
> +		 */
> +#define EFCT_TARGET_READ_SKIPS	2
> +		skips = EFCT_TARGET_READ_SKIPS;
> +		break;
> +	case EFCT_HW_IO_TARGET_RSP:
> +		/*
> +		 * No skips, etc. for FCP_TRSP64
> +		 */
> +		break;
> +	default:
> +		efc_log_err(hw->os, "unsupported IO type %#x\n", type);
> +		return EFCT_HW_RTN_ERROR;
> +	}
> +
> +	/*
> +	 * Write skip entries
> +	 */
> +	for (i = 0; i < skips; i++) {
> +		sge_flags = le32_to_cpu(data->dw2_flags);
> +		sge_flags &= (~SLI4_SGE_TYPE_MASK);
> +		sge_flags |= (SLI4_SGE_TYPE_SKIP << SLI4_SGE_TYPE_SHIFT);
> +		data->dw2_flags = cpu_to_le32(sge_flags);
> +		data++;
> +	}
> +
> +	io->n_sge += skips;
> +
> +	/*
> +	 * Set last
> +	 */
> +	sge_flags = le32_to_cpu(data->dw2_flags);
> +	sge_flags |= SLI4_SGE_LAST;
> +	data->dw2_flags = cpu_to_le32(sge_flags);
> +
> +	return EFCT_HW_RTN_SUCCESS;
> +}
> +
> +enum efct_hw_rtn
> +efct_hw_io_add_sge(struct efct_hw *hw, struct efct_hw_io *io,
> +		   uintptr_t addr, u32 length)
> +{
> +	struct sli4_sge	*data = NULL;
> +	u32 sge_flags = 0;
> +
> +	if (!io || !addr || !length) {
> +		efc_log_err(hw->os,
> +			     "bad parameter hw=%p io=%p addr=%lx length=%u\n",
> +			    hw, io, addr, length);
> +		return EFCT_HW_RTN_ERROR;
> +	}
> +
> +	if (length > hw->sli.sge_supported_length) {
> +		efc_log_err(hw->os,
> +			     "length of SGE %d bigger than allowed %d\n",
> +			    length, hw->sli.sge_supported_length);
> +		return EFCT_HW_RTN_ERROR;
> +	}
> +
> +	data = io->sgl->virt;
> +	data += io->n_sge;
> +
> +	sge_flags = le32_to_cpu(data->dw2_flags);
> +	sge_flags &= ~SLI4_SGE_TYPE_MASK;
> +	sge_flags |= SLI4_SGE_TYPE_DATA << SLI4_SGE_TYPE_SHIFT;
> +	sge_flags &= ~SLI4_SGE_DATA_OFFSET_MASK;
> +	sge_flags |= SLI4_SGE_DATA_OFFSET_MASK & io->sge_offset;
> +
> +	data->buffer_address_high = cpu_to_le32(upper_32_bits(addr));
> +	data->buffer_address_low  = cpu_to_le32(lower_32_bits(addr));
> +	data->buffer_length = cpu_to_le32(length);
> +
> +	/*
> +	 * Always assume this is the last entry and mark as such.
> +	 * If this is not the first entry unset the "last SGE"
> +	 * indication for the previous entry
> +	 */
> +	sge_flags |= SLI4_SGE_LAST;
> +	data->dw2_flags = cpu_to_le32(sge_flags);
> +
> +	if (io->n_sge) {
> +		sge_flags = le32_to_cpu(data[-1].dw2_flags);
> +		sge_flags &= ~SLI4_SGE_LAST;
> +		data[-1].dw2_flags = cpu_to_le32(sge_flags);
> +	}
> +
> +	/* Set first_data_bde if not previously set */
> +	if (io->first_data_sge == 0)
> +		io->first_data_sge = io->n_sge;
> +
> +	io->sge_offset += length;
> +	io->n_sge++;
> +
> +	/* Update the linked segment length (only executed after overflow has
> +	 * begun)
> +	 */
> +	if (io->ovfl_lsp)
> +		io->ovfl_lsp->dw3_seglen =
> +			cpu_to_le32(io->n_sge * sizeof(struct sli4_sge) &
> +				    SLI4_LSP_SGE_SEGLEN);
> +
> +	return EFCT_HW_RTN_SUCCESS;
> +}
> +
> +void
> +efct_hw_io_abort_all(struct efct_hw *hw)
> +{
> +	struct efct_hw_io *io_to_abort	= NULL;
> +	struct efct_hw_io *next_io = NULL;
> +
> +	list_for_each_entry_safe(io_to_abort, next_io,
> +				 &hw->io_inuse, list_entry) {
> +		efct_hw_io_abort(hw, io_to_abort, true, NULL, NULL);
> +	}
> +}
> +
> +static void
> +efct_hw_wq_process_abort(void *arg, u8 *cqe, int status)
> +{
> +	struct efct_hw_io *io = arg;
> +	struct efct_hw *hw = io->hw;
> +	u32 ext = 0;
> +	u32 len = 0;
> +	struct hw_wq_callback *wqcb;
> +	unsigned long flags = 0;
> +
> +	/*
> +	 * For IOs that were aborted internally, we may need to issue the
> +	 * callback here depending on whether a XRI_ABORTED CQE is expected ot
> +	 * not. If the status is Local Reject/No XRI, then
> +	 * issue the callback now.
> +	 */
> +	ext = sli_fc_ext_status(&hw->sli, cqe);
> +	if (status == SLI4_FC_WCQE_STATUS_LOCAL_REJECT &&
> +	    ext == SLI4_FC_LOCAL_REJECT_NO_XRI &&
> +		io->done) {
> +		efct_hw_done_t done = io->done;
> +		void *arg = io->arg;
> +
> +		io->done = NULL;
> +
> +		/*
> +		 * Use latched status as this is always saved for an internal
> +		 * abort Note: We wont have both a done and abort_done
> +		 * function, so don't worry about
> +		 *       clobbering the len, status and ext fields.
> +		 */
> +		status = io->saved_status;
> +		len = io->saved_len;
> +		ext = io->saved_ext;
> +		io->status_saved = false;
> +		done(io, io->rnode, len, status, ext, arg);
> +	}
> +
> +	if (io->abort_done) {
> +		efct_hw_done_t done = io->abort_done;
> +		void *arg = io->abort_arg;
> +
> +		io->abort_done = NULL;
> +
> +		done(io, io->rnode, len, status, ext, arg);
> +	}
> +	spin_lock_irqsave(&hw->io_abort_lock, flags);
> +	/* clear abort bit to indicate abort is complete */
> +	io->abort_in_progress = false;
> +	spin_unlock_irqrestore(&hw->io_abort_lock, flags);
> +
> +	/* Free the WQ callback */
> +	if (io->abort_reqtag == U32_MAX) {
> +		efc_log_err(hw->os, "HW IO already freed\n");
> +		return;
> +	}
> +
> +	wqcb = efct_hw_reqtag_get_instance(hw, io->abort_reqtag);
> +	efct_hw_reqtag_free(hw, wqcb);
> +
> +	/*
> +	 * Call efct_hw_io_free() because this releases the WQ reservation as
> +	 * well as doing the refcount put. Don't duplicate the code here.
> +	 */
> +	(void)efct_hw_io_free(hw, io);
> +}
> +
> +enum efct_hw_rtn
> +efct_hw_io_abort(struct efct_hw *hw, struct efct_hw_io *io_to_abort,
> +		 bool send_abts, void *cb, void *arg)
> +{
> +	enum sli4_abort_type atype = SLI_ABORT_MAX;
> +	u32 id = 0, mask = 0;
> +	enum efct_hw_rtn rc = EFCT_HW_RTN_SUCCESS;
> +	struct hw_wq_callback *wqcb;
> +	unsigned long flags = 0;
> +
> +	if (!io_to_abort) {
> +		efc_log_err(hw->os,
> +			     "bad parameter hw=%p io=%p\n",
> +			    hw, io_to_abort);
> +		return EFCT_HW_RTN_ERROR;
> +	}
> +
> +	if (hw->state != EFCT_HW_STATE_ACTIVE) {
> +		efc_log_err(hw->os, "cannot send IO abort, HW state=%d\n",
> +			     hw->state);
> +		return EFCT_HW_RTN_ERROR;
> +	}
> +
> +	/* take a reference on IO being aborted */
> +	if (kref_get_unless_zero(&io_to_abort->ref) == 0) {
> +		/* command no longer active */
> +		efc_log_test(hw->os,
> +			      "io not active xri=0x%x tag=0x%x\n",
> +			     io_to_abort->indicator, io_to_abort->reqtag);
> +		return EFCT_HW_RTN_IO_NOT_ACTIVE;
> +	}
> +
> +	/* Must have a valid WQ reference */
> +	if (!io_to_abort->wq) {
> +		efc_log_test(hw->os, "io_to_abort xri=0x%x not active on WQ\n",
> +			      io_to_abort->indicator);
> +		/* efct_ref_get(): same function */
> +		kref_put(&io_to_abort->ref, io_to_abort->release);
> +		return EFCT_HW_RTN_IO_NOT_ACTIVE;
> +	}
> +
> +	/*
> +	 * Validation checks complete; now check to see if already being
> +	 * aborted
> +	 */
> +	spin_lock_irqsave(&hw->io_abort_lock, flags);
> +	if (io_to_abort->abort_in_progress) {
> +		spin_unlock_irqrestore(&hw->io_abort_lock, flags);
> +		/* efct_ref_get(): same function */
> +		kref_put(&io_to_abort->ref, io_to_abort->release);
> +		efc_log_debug(hw->os,
> +			       "io already being aborted xri=0x%x tag=0x%x\n",
> +			      io_to_abort->indicator, io_to_abort->reqtag);
> +		return EFCT_HW_RTN_IO_ABORT_IN_PROGRESS;
> +	}
> +
> +	/*
> +	 * This IO is not already being aborted. Set flag so we won't try to
> +	 * abort it again. After all, we only have one abort_done callback.
> +	 */
> +	io_to_abort->abort_in_progress = true;
> +	spin_unlock_irqrestore(&hw->io_abort_lock, flags);
> +
> +	/*
> +	 * If we got here, the possibilities are:
> +	 * - host owned xri
> +	 *	- io_to_abort->wq_index != U32_MAX
> +	 *		- submit ABORT_WQE to same WQ
> +	 * - port owned xri:
> +	 *	- rxri: io_to_abort->wq_index == U32_MAX
> +	 *		- submit ABORT_WQE to any WQ
> +	 *	- non-rxri
> +	 *		- io_to_abort->index != U32_MAX
> +	 *			- submit ABORT_WQE to same WQ
> +	 *		- io_to_abort->index == U32_MAX
> +	 *			- submit ABORT_WQE to any WQ
> +	 */
> +	io_to_abort->abort_done = cb;
> +	io_to_abort->abort_arg  = arg;
> +
> +	atype = SLI_ABORT_XRI;
> +	id = io_to_abort->indicator;
> +
> +	/* Allocate a request tag for the abort portion of this IO */
> +	wqcb = efct_hw_reqtag_alloc(hw, efct_hw_wq_process_abort, io_to_abort);
> +	if (!wqcb) {
> +		efc_log_err(hw->os, "can't allocate request tag\n");
> +		return EFCT_HW_RTN_NO_RESOURCES;
> +	}
> +	io_to_abort->abort_reqtag = wqcb->instance_index;
> +
> +	/*
> +	 * If the wqe is on the pending list, then set this wqe to be
> +	 * aborted when the IO's wqe is removed from the list.
> +	 */
> +	if (io_to_abort->wq) {
> +		spin_lock_irqsave(&io_to_abort->wq->queue->lock, flags);
> +		if (io_to_abort->wqe.list_entry.next) {
> +			io_to_abort->wqe.abort_wqe_submit_needed = true;
> +			io_to_abort->wqe.send_abts = send_abts;
> +			io_to_abort->wqe.id = id;
> +			io_to_abort->wqe.abort_reqtag =
> +						 io_to_abort->abort_reqtag;
> +			spin_unlock_irqrestore(&io_to_abort->wq->queue->lock,
> +					       flags);
> +			return EFC_SUCCESS;
> +		}
> +		spin_unlock_irqrestore(&io_to_abort->wq->queue->lock, flags);
> +	}
> +
> +	if (sli_abort_wqe(&hw->sli, io_to_abort->wqe.wqebuf,
> +			  hw->sli.wqe_size, atype, send_abts, id, mask,
> +			  io_to_abort->abort_reqtag, SLI4_CQ_DEFAULT)) {
> +		efc_log_err(hw->os, "ABORT WQE error\n");
> +		io_to_abort->abort_reqtag = U32_MAX;
> +		efct_hw_reqtag_free(hw, wqcb);
> +		rc = EFCT_HW_RTN_ERROR;
> +	}
> +
> +	if (rc == EFCT_HW_RTN_SUCCESS) {
> +
> +		/* ABORT_WQE does not actually utilize an XRI on the Port,
> +		 * therefore, keep xbusy as-is to track the exchange's state,
> +		 * not the ABORT_WQE's state
> +		 */
> +		rc = efct_hw_wq_write(io_to_abort->wq, &io_to_abort->wqe);
> +		if (rc > 0)
> +			/* non-negative return is success */
> +			rc = 0;
> +			/*
> +			 * can't abort an abort so skip adding to timed wqe
> +			 * list
> +			 */
> +	}
> +
> +	if (rc != EFCT_HW_RTN_SUCCESS) {
> +		spin_lock_irqsave(&hw->io_abort_lock, flags);
> +		io_to_abort->abort_in_progress = false;
> +		spin_unlock_irqrestore(&hw->io_abort_lock, flags);
> +		/* efct_ref_get(): same function */
> +		kref_put(&io_to_abort->ref, io_to_abort->release);
> +	}
> +	return rc;
> +}
> +
> +void
> +efct_hw_reqtag_pool_free(struct efct_hw *hw)
> +{
> +	u32 i = 0;
> +	struct reqtag_pool *reqtag_pool = hw->wq_reqtag_pool;
> +	struct hw_wq_callback *wqcb = NULL;
> +
> +	if (reqtag_pool) {
> +		for (i = 0; i < U16_MAX; i++) {
> +			wqcb = reqtag_pool->tags[i];
> +			if (!wqcb)
> +				continue;
> +
> +			kfree(wqcb);
> +		}
> +		kfree(reqtag_pool);
> +		hw->wq_reqtag_pool = NULL;
> +	}
> +}
> +
> +struct reqtag_pool *
> +efct_hw_reqtag_pool_alloc(struct efct_hw *hw)
> +{
> +	u32 i = 0;
> +	struct reqtag_pool *reqtag_pool;
> +	struct hw_wq_callback *wqcb;
> +
> +	reqtag_pool = kzalloc(sizeof(*reqtag_pool), GFP_KERNEL);
> +	if (!reqtag_pool)
> +		return NULL;
> +
> +	INIT_LIST_HEAD(&reqtag_pool->freelist);
> +	/* initialize reqtag pool lock */
> +	spin_lock_init(&reqtag_pool->lock);
> +	for (i = 0; i < U16_MAX; i++) {
> +		wqcb = kmalloc(sizeof(*wqcb), GFP_KERNEL);
> +		if (!wqcb)
> +			break;
> +
> +		reqtag_pool->tags[i] = wqcb;
> +		wqcb->instance_index = i;
> +		wqcb->callback = NULL;
> +		wqcb->arg = NULL;
> +		INIT_LIST_HEAD(&wqcb->list_entry);
> +		list_add_tail(&wqcb->list_entry, &reqtag_pool->freelist);
> +	}
> +
> +	return reqtag_pool;
> +}
> +
> +struct hw_wq_callback *
> +efct_hw_reqtag_alloc(struct efct_hw *hw,
> +		     void (*callback)(void *arg, u8 *cqe, int status),
> +		     void *arg)
> +{
> +	struct hw_wq_callback *wqcb = NULL;
> +	struct reqtag_pool *reqtag_pool = hw->wq_reqtag_pool;
> +	unsigned long flags = 0;
> +
> +	if (!callback)
> +		return wqcb;
> +
> +	spin_lock_irqsave(&reqtag_pool->lock, flags);
> +
> +	if (!list_empty(&reqtag_pool->freelist)) {
> +		wqcb = list_first_entry(&reqtag_pool->freelist,
> +				      struct hw_wq_callback, list_entry);
> +	}
> +
> +	if (wqcb) {
> +		list_del(&wqcb->list_entry);
> +		spin_unlock_irqrestore(&reqtag_pool->lock, flags);
> +		wqcb->callback = callback;
> +		wqcb->arg = arg;
> +	} else {
> +		spin_unlock_irqrestore(&reqtag_pool->lock, flags);
> +	}
> +
> +	return wqcb;
> +}
> +
> +void
> +efct_hw_reqtag_free(struct efct_hw *hw, struct hw_wq_callback *wqcb)
> +{
> +	unsigned long flags = 0;
> +	struct reqtag_pool *reqtag_pool = hw->wq_reqtag_pool;
> +
> +	if (!wqcb->callback)
> +		efc_log_err(hw->os, "WQCB is already freed\n");
> +
> +	spin_lock_irqsave(&reqtag_pool->lock, flags);
> +	wqcb->callback = NULL;
> +	wqcb->arg = NULL;
> +	INIT_LIST_HEAD(&wqcb->list_entry);
> +	list_add(&wqcb->list_entry, &hw->wq_reqtag_pool->freelist);
> +	spin_unlock_irqrestore(&reqtag_pool->lock, flags);
> +}
> +
> +struct hw_wq_callback *
> +efct_hw_reqtag_get_instance(struct efct_hw *hw, u32 instance_index)
> +{
> +	struct hw_wq_callback *wqcb;
> +
> +	wqcb = hw->wq_reqtag_pool->tags[instance_index];
> +	if (!wqcb)
> +		efc_log_err(hw->os, "wqcb for instance %d is null\n",
> +			     instance_index);
> +
> +	return wqcb;
> +}
> +
> +void
> +efct_hw_reqtag_reset(struct efct_hw *hw)
> +{
> +	struct hw_wq_callback *wqcb;
> +	u32 i;
> +	struct reqtag_pool *reqtag_pool = hw->wq_reqtag_pool;
> +	struct list_head *p, *n;
> +
> +	/* Remove all from freelist */
> +	list_for_each_safe(p, n, &reqtag_pool->freelist) {
> +		wqcb = list_entry(p, struct hw_wq_callback, list_entry);
> +
> +		if (wqcb)
> +			list_del(&wqcb->list_entry);
> +	}
> +
> +	/* Put them all back */
> +	for (i = 0; i < ARRAY_SIZE(reqtag_pool->tags); i++) {
> +		wqcb = reqtag_pool->tags[i];
> +		wqcb->instance_index = i;
> +		wqcb->callback = NULL;
> +		wqcb->arg = NULL;
> +		INIT_LIST_HEAD(&wqcb->list_entry);
> +		list_add_tail(&wqcb->list_entry, &reqtag_pool->freelist);
> +	}
> +}
> diff --git a/drivers/scsi/elx/efct/efct_hw.h b/drivers/scsi/elx/efct/efct_hw.h
> index 1b67e0721936..86736d5295ec 100644
> --- a/drivers/scsi/elx/efct/efct_hw.h
> +++ b/drivers/scsi/elx/efct/efct_hw.h
> @@ -635,5 +635,47 @@ void efct_hw_rx_free(struct efct_hw *hw);
>  extern enum efct_hw_rtn
>  efct_hw_command(struct efct_hw *hw, u8 *cmd, u32 opts, void *cb,
>  		void *arg);
> +struct efct_hw_io *efct_hw_io_alloc(struct efct_hw *hw);
> +int efct_hw_io_free(struct efct_hw *hw, struct efct_hw_io *io);
> +u8 efct_hw_io_inuse(struct efct_hw *hw, struct efct_hw_io *io);
> +extern enum efct_hw_rtn
> +efct_hw_io_send(struct efct_hw *hw, enum efct_hw_io_type type,
> +		struct efct_hw_io *io, u32 len,
> +		union efct_hw_io_param_u *iparam,
> +		struct efc_remote_node *rnode, void *cb, void *arg);
> +extern enum efct_hw_rtn
> +efct_hw_io_register_sgl(struct efct_hw *hw, struct efct_hw_io *io,
> +			struct efc_dma *sgl,
> +			u32 sgl_count);
> +extern enum efct_hw_rtn
> +efct_hw_io_init_sges(struct efct_hw *hw,
> +		     struct efct_hw_io *io, enum efct_hw_io_type type);
> +
> +extern enum efct_hw_rtn
> +efct_hw_io_add_sge(struct efct_hw *hw, struct efct_hw_io *io,
> +		   uintptr_t addr, u32 length);
> +extern enum efct_hw_rtn
> +efct_hw_io_abort(struct efct_hw *hw, struct efct_hw_io *io_to_abort,
> +		 bool send_abts, void *cb, void *arg);
> +extern u32
> +efct_hw_io_get_count(struct efct_hw *hw,
> +		     enum efct_hw_io_count_type io_count_type);
> +extern struct efct_hw_io
> +*efct_hw_io_lookup(struct efct_hw *hw, u32 indicator);
> +void efct_hw_io_abort_all(struct efct_hw *hw);
> +void efct_hw_io_free_internal(struct kref *arg);
> +
> +/* HW WQ request tag API */
> +struct reqtag_pool *efct_hw_reqtag_pool_alloc(struct efct_hw *hw);
> +void efct_hw_reqtag_pool_free(struct efct_hw *hw);
> +extern struct hw_wq_callback
> +*efct_hw_reqtag_alloc(struct efct_hw *hw,
> +			void (*callback)(void *arg, u8 *cqe,
> +					 int status), void *arg);
> +extern void
> +efct_hw_reqtag_free(struct efct_hw *hw, struct hw_wq_callback *wqcb);
> +extern struct hw_wq_callback
> +*efct_hw_reqtag_get_instance(struct efct_hw *hw, u32 instance_index);
> +void efct_hw_reqtag_reset(struct efct_hw *hw);
>  
>  #endif /* __EFCT_H__ */
> -- 
> 2.16.4
> 

Thanks,
Daniel