Re: [PATCH v4 21/31] elx: efct: Hardware IO and SGL initialization

[Hannes Reinecke <hare@suse.de>]

On 10/13/20 12:51 AM, 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.
> 
> Co-developed-by: Ram Vegesna <ram.vegesna@broadcom.com>
> Signed-off-by: Ram Vegesna <ram.vegesna@broadcom.com>
> Signed-off-by: James Smart <james.smart@broadcom.com>
> ---
>   drivers/scsi/elx/efct/efct_hw.c | 590 ++++++++++++++++++++++++++++++++
>   drivers/scsi/elx/efct/efct_hw.h |  41 +++
>   2 files changed, 631 insertions(+)
> 
> diff --git a/drivers/scsi/elx/efct/efct_hw.c b/drivers/scsi/elx/efct/efct_hw.c
> index fdde7f70bedf..3df46eb20fa1 100644
> --- a/drivers/scsi/elx/efct/efct_hw.c
> +++ b/drivers/scsi/elx/efct/efct_hw.c
> @@ -1575,3 +1575,593 @@ efct_issue_mbox_rqst(void *base, void *cmd, void *cb, void *arg)
>   	}
>   	return rc;
>   }
> +
> +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);
> +		list_add_tail(&io->list_entry, &hw->io_inuse);
> +		io->state = EFCT_HW_IO_STATE_INUSE;
> +		io->abort_reqtag = U32_MAX;
> +		io->wq = hw->wq_cpu_array[raw_smp_processor_id()];
> +		if (!io->wq) {
> +			efc_log_err(hw->os, "WQ not assigned for cpu:%d\n",
> +					raw_smp_processor_id());
> +			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;
> +}
> +
> +static void
> +efct_hw_io_free_move_correct_list(struct efct_hw *hw,
> +				  struct efct_hw_io *io)
> +{
> +
> +	/*
> +	 * When an IO is freed, depending on the exchange busy flag,
> +	 * move it to the correct list.
> +	 */
> +	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);
> +}
> +
> +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);
> +	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);
> +	}
> +	spin_unlock_irqrestore(&hw->io_lock, flags);
> +}
> +

You don't really believe in list_del_init(), do you?
I would consider checking all instances of 'list_del()' on whether it'd 
be better to use 'list_del_init()', seeing that then one could do a 
'list_empty' check on the element to figure out if it's queued or not...

> +int
> +efct_hw_io_free(struct efct_hw *hw, struct efct_hw_io *io)
> +{
> +	return kref_put(&io->ref, io->release);
> +}
> +
> +struct efct_hw_io *
> +efct_hw_io_lookup(struct efct_hw *hw, u32 xri)
> +{
> +	u32 ioindex;
> +
> +	ioindex = xri - hw->sli.ext[SLI4_RSRC_XRI].base[0];
> +	return hw->io[ioindex];
> +}
> +
> +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:
> +
> +		/* 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 = EFCT_TARGET_WRITE_SKIPS;
> +
> +		io->n_sge = 1;
> +		break;
> +	case EFCT_HW_IO_TARGET_READ:
> +		/*
> +		 * For FCP_TSEND64, the first 2 entries are SKIP SGE's
> +		 */
> +		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++;
> +
> +	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;
> +
> +		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, len, status, ext, io->arg);
> +	}
> +
> +	if (io->abort_done) {
> +		efct_hw_done_t done = io->abort_done;
> +
> +		io->abort_done = NULL;
> +		done(io, len, status, ext, io->abort_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);
> +}
> +
> +static void
> +efct_hw_fill_abort_wqe(struct efct_hw *hw, struct efct_hw_wqe *wqe)
> +{
> +	struct sli4_abort_wqe *abort = (void *)wqe->wqebuf;
> +
> +	memset(abort, 0, hw->sli.wqe_size);
> +
> +	abort->criteria = SLI4_ABORT_CRITERIA_XRI_TAG;
> +	abort->ia_ir_byte |= wqe->send_abts ? 0 : 1;
> +
> +	/* Suppress ABTS retries */
> +	abort->ia_ir_byte |= SLI4_ABRT_WQE_IR;
> +
> +	abort->t_tag  = cpu_to_le32(wqe->id);
> +	abort->command = SLI4_WQE_ABORT;
> +	abort->request_tag = cpu_to_le16(wqe->abort_reqtag);
> +
> +	abort->dw10w0_flags = cpu_to_le16(SLI4_ABRT_WQE_QOSD);
> +
> +	abort->cq_id = cpu_to_le16(SLI4_CQ_DEFAULT);
> +}
> +
> +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)
> +{
> +	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;
> +
> +	/* 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;
> +	io_to_abort->wqe.send_abts = send_abts;
> +	io_to_abort->wqe.id = io_to_abort->indicator;
> +	io_to_abort->wqe.abort_reqtag = io_to_abort->abort_reqtag;
> +
> +	/*
> +	 * 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;
> +			spin_unlock_irqrestore(&io_to_abort->wq->queue->lock,
> +					       flags);
> +			return EFC_SUCCESS;
> +		}
> +		spin_unlock_irqrestore(&io_to_abort->wq->queue->lock, flags);
> +	}
> +
> +	efct_hw_fill_abort_wqe(hw, &io_to_abort->wqe);
> +
> +	/* 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
> +	 */
> +	if (efct_hw_wq_write(io_to_abort->wq, &io_to_abort->wqe)) {
> +		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 EFC_FAIL;
> +	}
> +
> +	return EFC_SUCCESS;
> +}
> +
> +void
> +efct_hw_reqtag_pool_free(struct efct_hw *hw)
> +{
> +	u32 i;
> +	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;
> +}

Have you considered using sbitmap for tracking the 'reqtag' instances?

> diff --git a/drivers/scsi/elx/efct/efct_hw.h b/drivers/scsi/elx/efct/efct_hw.h
> index 03787da3f4f7..f90f78ab73d8 100644
> --- a/drivers/scsi/elx/efct/efct_hw.h
> +++ b/drivers/scsi/elx/efct/efct_hw.h
> @@ -628,4 +628,45 @@ efct_hw_command(struct efct_hw *hw, u8 *cmd, u32 opts, void *cb,
>   int
>   efct_issue_mbox_rqst(void *base, void *cmd, 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);
> +enum efct_hw_rtn
> +efct_hw_io_send(struct efct_hw *hw, enum efct_hw_io_type type,
> +		struct efct_hw_io *io, union efct_hw_io_param_u *iparam,
> +		void *cb, void *arg);
> +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);
> +enum efct_hw_rtn
> +efct_hw_io_init_sges(struct efct_hw *hw,
> +		     struct efct_hw_io *io, enum efct_hw_io_type type);
> +
> +enum efct_hw_rtn
> +efct_hw_io_add_sge(struct efct_hw *hw, struct efct_hw_io *io,
> +		   uintptr_t addr, u32 length);
> +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);
> +u32
> +efct_hw_io_get_count(struct efct_hw *hw,
> +		     enum efct_hw_io_count_type io_count_type);
> +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);
> +struct hw_wq_callback
> +*efct_hw_reqtag_alloc(struct efct_hw *hw,
> +			void (*callback)(void *arg, u8 *cqe,
> +					 int status), void *arg);
> +void
> +efct_hw_reqtag_free(struct efct_hw *hw, struct hw_wq_callback *wqcb);
> +struct hw_wq_callback
> +*efct_hw_reqtag_get_instance(struct efct_hw *hw, u32 instance_index);
> +
>   #endif /* __EFCT_H__ */
> 
Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
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