Re: [PATCH v3 08/31] elx: libefc: Generic state machine framework

[Daniel Wagner <dwagner@suse.de>]

On Sat, Apr 11, 2020 at 08:32:40PM -0700, James Smart wrote:
> This patch starts the population of the libefc library.
> The library will contain common tasks usable by a target or initiator
> driver. The library will also contain a FC discovery state machine
> interface.
> 
> This patch creates the library directory and adds definitions
> for the discovery state machine interface.
> 
> Signed-off-by: Ram Vegesna <ram.vegesna@broadcom.com>
> Signed-off-by: James Smart <jsmart2021@gmail.com>
> 
> ---
> v3:
>   Removed efc_sm_id array which is not used.
>   Added State Machine event name lookup array.
> ---
>  drivers/scsi/elx/libefc/efc_sm.c |  61 ++++++++++++
>  drivers/scsi/elx/libefc/efc_sm.h | 209 +++++++++++++++++++++++++++++++++++++++
>  2 files changed, 270 insertions(+)
>  create mode 100644 drivers/scsi/elx/libefc/efc_sm.c
>  create mode 100644 drivers/scsi/elx/libefc/efc_sm.h
> 
> diff --git a/drivers/scsi/elx/libefc/efc_sm.c b/drivers/scsi/elx/libefc/efc_sm.c
> new file mode 100644
> index 000000000000..aba9d542f22e
> --- /dev/null
> +++ b/drivers/scsi/elx/libefc/efc_sm.c
> @@ -0,0 +1,61 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2019 Broadcom. All Rights Reserved. The term
> + * “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.
> + */
> +
> +/*
> + * Generic state machine framework.
> + */
> +#include "efc.h"
> +#include "efc_sm.h"
> +
> +/**
> + * efc_sm_post_event() - Post an event to a context.
> + *
> + * @ctx: State machine context
> + * @evt: Event to post
> + * @data: Event-specific data (if any)
> + */
> +int
> +efc_sm_post_event(struct efc_sm_ctx *ctx,
> +		  enum efc_sm_event evt, void *data)
> +{
> +	if (ctx->current_state) {
> +		ctx->current_state(ctx, evt, data);
> +		return EFC_SUCCESS;
> +	} else {
> +		return EFC_FAIL;
> +	}

	if (!ctx->current_state)
		return EFC_FAIL;

	ctx->current_state(ctx, evt, data);
	return EFC_SUCCESS;


> +}
> +
> +void
> +efc_sm_transition(struct efc_sm_ctx *ctx,
> +		  void *(*state)(struct efc_sm_ctx *,
> +				 enum efc_sm_event, void *), void *data)
> +
> +{
> +	if (ctx->current_state == state) {
> +		efc_sm_post_event(ctx, EFC_EVT_REENTER, data);
> +	} else {
> +		efc_sm_post_event(ctx, EFC_EVT_EXIT, data);
> +		ctx->current_state = state;
> +		efc_sm_post_event(ctx, EFC_EVT_ENTER, data);
> +	}
> +}
> +
> +void
> +efc_sm_disable(struct efc_sm_ctx *ctx)
> +{
> +	ctx->current_state = NULL;
> +}
> +
> +static char *event_name[] = EFC_SM_EVENT_NAME;
> +
> +const char *efc_sm_event_name(enum efc_sm_event evt)
> +{
> +	if (evt > EFC_EVT_LAST)
> +		return "unknown";
> +
> +	return event_name[evt];
> +}
> diff --git a/drivers/scsi/elx/libefc/efc_sm.h b/drivers/scsi/elx/libefc/efc_sm.h
> new file mode 100644
> index 000000000000..9cb534a1b86e
> --- /dev/null
> +++ b/drivers/scsi/elx/libefc/efc_sm.h
> @@ -0,0 +1,209 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (C) 2019 Broadcom. All Rights Reserved. The term
> + * “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.
> + *
> + */
> +
> +/**
> + * Generic state machine framework declarations.
> + */
> +
> +#ifndef _EFC_SM_H
> +#define _EFC_SM_H
> +
> +/**
> + * State Machine (SM) IDs.
> + */
> +enum {
> +	EFC_SM_COMMON = 0,
> +	EFC_SM_DOMAIN,
> +	EFC_SM_PORT,
> +	EFC_SM_LOGIN,
> +	EFC_SM_LAST
> +};
> +
> +#define EFC_SM_EVENT_SHIFT		8
> +#define EFC_SM_EVENT_START(id)		((id) << EFC_SM_EVENT_SHIFT)
> +
> +struct efc_sm_ctx;
> +
> +/* State Machine events */
> +enum efc_sm_event {
> +	/* Common Events */
> +	EFC_EVT_ENTER = EFC_SM_EVENT_START(EFC_SM_COMMON),
> +	EFC_EVT_REENTER,
> +	EFC_EVT_EXIT,
> +	EFC_EVT_SHUTDOWN,
> +	EFC_EVT_ALL_CHILD_NODES_FREE,
> +	EFC_EVT_RESUME,
> +	EFC_EVT_TIMER_EXPIRED,
> +
> +	/* Domain Events */
> +	EFC_EVT_RESPONSE = EFC_SM_EVENT_START(EFC_SM_DOMAIN),
> +	EFC_EVT_ERROR,
> +
> +	EFC_EVT_DOMAIN_FOUND,
> +	EFC_EVT_DOMAIN_ALLOC_OK,
> +	EFC_EVT_DOMAIN_ALLOC_FAIL,
> +	EFC_EVT_DOMAIN_REQ_ATTACH,
> +	EFC_EVT_DOMAIN_ATTACH_OK,
> +	EFC_EVT_DOMAIN_ATTACH_FAIL,
> +	EFC_EVT_DOMAIN_LOST,
> +	EFC_EVT_DOMAIN_FREE_OK,
> +	EFC_EVT_DOMAIN_FREE_FAIL,
> +	EFC_EVT_HW_DOMAIN_REQ_ATTACH,
> +	EFC_EVT_HW_DOMAIN_REQ_FREE,
> +
> +	/* Sport Events */
> +	EFC_EVT_SPORT_ALLOC_OK = EFC_SM_EVENT_START(EFC_SM_PORT),
> +	EFC_EVT_SPORT_ALLOC_FAIL,
> +	EFC_EVT_SPORT_ATTACH_OK,
> +	EFC_EVT_SPORT_ATTACH_FAIL,
> +	EFC_EVT_SPORT_FREE_OK,
> +	EFC_EVT_SPORT_FREE_FAIL,
> +	EFC_EVT_SPORT_TOPOLOGY_NOTIFY,
> +	EFC_EVT_HW_PORT_ALLOC_OK,
> +	EFC_EVT_HW_PORT_ALLOC_FAIL,
> +	EFC_EVT_HW_PORT_ATTACH_OK,
> +	EFC_EVT_HW_PORT_REQ_ATTACH,
> +	EFC_EVT_HW_PORT_REQ_FREE,
> +	EFC_EVT_HW_PORT_FREE_OK,
> +
> +	/* Login Events */
> +	EFC_EVT_SRRS_ELS_REQ_OK = EFC_SM_EVENT_START(EFC_SM_LOGIN),
> +	EFC_EVT_SRRS_ELS_CMPL_OK,
> +	EFC_EVT_SRRS_ELS_REQ_FAIL,
> +	EFC_EVT_SRRS_ELS_CMPL_FAIL,
> +	EFC_EVT_SRRS_ELS_REQ_RJT,
> +	EFC_EVT_NODE_ATTACH_OK,
> +	EFC_EVT_NODE_ATTACH_FAIL,
> +	EFC_EVT_NODE_FREE_OK,
> +	EFC_EVT_NODE_FREE_FAIL,
> +	EFC_EVT_ELS_FRAME,
> +	EFC_EVT_ELS_REQ_TIMEOUT,
> +	EFC_EVT_ELS_REQ_ABORTED,
> +	/* request an ELS IO be aborted */
> +	EFC_EVT_ABORT_ELS,
> +	/* ELS abort process complete */
> +	EFC_EVT_ELS_ABORT_CMPL,
> +
> +	EFC_EVT_ABTS_RCVD,
> +
> +	/* node is not in the GID_PT payload */
> +	EFC_EVT_NODE_MISSING,
> +	/* node is allocated and in the GID_PT payload */
> +	EFC_EVT_NODE_REFOUND,
> +	/* node shutting down due to PLOGI recvd (implicit logo) */
> +	EFC_EVT_SHUTDOWN_IMPLICIT_LOGO,
> +	/* node shutting down due to LOGO recvd/sent (explicit logo) */
> +	EFC_EVT_SHUTDOWN_EXPLICIT_LOGO,
> +
> +	EFC_EVT_PLOGI_RCVD,
> +	EFC_EVT_FLOGI_RCVD,
> +	EFC_EVT_LOGO_RCVD,
> +	EFC_EVT_PRLI_RCVD,
> +	EFC_EVT_PRLO_RCVD,
> +	EFC_EVT_PDISC_RCVD,
> +	EFC_EVT_FDISC_RCVD,
> +	EFC_EVT_ADISC_RCVD,
> +	EFC_EVT_RSCN_RCVD,
> +	EFC_EVT_SCR_RCVD,
> +	EFC_EVT_ELS_RCVD,
> +
> +	EFC_EVT_FCP_CMD_RCVD,
> +
> +	EFC_EVT_GIDPT_DELAY_EXPIRED,
> +
> +	/* SCSI Target Server events */
> +	EFC_EVT_NODE_ACTIVE_IO_LIST_EMPTY,
> +	EFC_EVT_NODE_DEL_INI_COMPLETE,
> +	EFC_EVT_NODE_DEL_TGT_COMPLETE,
> +
> +	/* Must be last */
> +	EFC_EVT_LAST
> +};
> +
> +/* State Machine event name lookup array */
> +#define EFC_SM_EVENT_NAME {						\
> +	[EFC_EVT_ENTER]			= "EFC_EVT_ENTER",		\
> +	[EFC_EVT_REENTER]		= "EFC_EVT_REENTER",		\
> +	[EFC_EVT_EXIT]			= "EFC_EVT_EXIT",		\
> +	[EFC_EVT_SHUTDOWN]		= "EFC_EVT_SHUTDOWN",		\
> +	[EFC_EVT_ALL_CHILD_NODES_FREE]	= "EFC_EVT_ALL_CHILD_NODES_FREE",\
> +	[EFC_EVT_RESUME]		= "EFC_EVT_RESUME",		\
> +	[EFC_EVT_TIMER_EXPIRED]		= "EFC_EVT_TIMER_EXPIRED",	\
> +	[EFC_EVT_RESPONSE]		= "EFC_EVT_RESPONSE",		\
> +	[EFC_EVT_ERROR]			= "EFC_EVT_ERROR",		\
> +	[EFC_EVT_DOMAIN_FOUND]		= "EFC_EVT_DOMAIN_FOUND",	\
> +	[EFC_EVT_DOMAIN_ALLOC_OK]	= "EFC_EVT_DOMAIN_ALLOC_OK",	\
> +	[EFC_EVT_DOMAIN_ALLOC_FAIL]	= "EFC_EVT_DOMAIN_ALLOC_FAIL",	\
> +	[EFC_EVT_DOMAIN_REQ_ATTACH]	= "EFC_EVT_DOMAIN_REQ_ATTACH",	\
> +	[EFC_EVT_DOMAIN_ATTACH_OK]	= "EFC_EVT_DOMAIN_ATTACH_OK",	\
> +	[EFC_EVT_DOMAIN_ATTACH_FAIL]	= "EFC_EVT_DOMAIN_ATTACH_FAIL",	\
> +	[EFC_EVT_DOMAIN_LOST]		= "EFC_EVT_DOMAIN_LOST",	\
> +	[EFC_EVT_DOMAIN_FREE_OK]	= "EFC_EVT_DOMAIN_FREE_OK",	\
> +	[EFC_EVT_DOMAIN_FREE_FAIL]	= "EFC_EVT_DOMAIN_FREE_FAIL",	\
> +	[EFC_EVT_HW_DOMAIN_REQ_ATTACH]	= "EFC_EVT_HW_DOMAIN_REQ_ATTACH",\
> +	[EFC_EVT_HW_DOMAIN_REQ_FREE]	= "EFC_EVT_HW_DOMAIN_REQ_FREE",	\
> +	[EFC_EVT_SPORT_ALLOC_OK]	= "EFC_EVT_SPORT_ALLOC_OK",	\
> +	[EFC_EVT_SPORT_ALLOC_FAIL]	= "EFC_EVT_SPORT_ALLOC_FAIL",	\
> +	[EFC_EVT_SPORT_ATTACH_OK]	= "EFC_EVT_SPORT_ATTACH_OK",	\
> +	[EFC_EVT_SPORT_ATTACH_FAIL]	= "EFC_EVT_SPORT_ATTACH_FAIL",	\
> +	[EFC_EVT_SPORT_FREE_OK]		= "EFC_EVT_SPORT_FREE_OK",	\
> +	[EFC_EVT_SPORT_FREE_FAIL]	= "EFC_EVT_SPORT_FREE_FAIL",	\
> +	[EFC_EVT_SPORT_TOPOLOGY_NOTIFY]	= "EFC_EVT_SPORT_TOPOLOGY_NOTIFY",\
> +	[EFC_EVT_HW_PORT_ALLOC_OK]	= "EFC_EVT_HW_PORT_ALLOC_OK",	\
> +	[EFC_EVT_HW_PORT_ALLOC_FAIL]	= "EFC_EVT_HW_PORT_ALLOC_FAIL",	\
> +	[EFC_EVT_HW_PORT_ATTACH_OK]	= "EFC_EVT_HW_PORT_ATTACH_OK",	\
> +	[EFC_EVT_HW_PORT_REQ_ATTACH]	= "EFC_EVT_HW_PORT_REQ_ATTACH",	\
> +	[EFC_EVT_HW_PORT_REQ_FREE]	= "EFC_EVT_HW_PORT_REQ_FREE",	\
> +	[EFC_EVT_HW_PORT_FREE_OK]	= "EFC_EVT_HW_PORT_FREE_OK",	\
> +	[EFC_EVT_SRRS_ELS_REQ_OK]	= "EFC_EVT_SRRS_ELS_REQ_OK",	\
> +	[EFC_EVT_SRRS_ELS_CMPL_OK]	= "EFC_EVT_SRRS_ELS_CMPL_OK",	\
> +	[EFC_EVT_SRRS_ELS_REQ_FAIL]	= "EFC_EVT_SRRS_ELS_REQ_FAIL",	\
> +	[EFC_EVT_SRRS_ELS_CMPL_FAIL]	= "EFC_EVT_SRRS_ELS_CMPL_FAIL",	\
> +	[EFC_EVT_SRRS_ELS_REQ_RJT]	= "EFC_EVT_SRRS_ELS_REQ_RJT",	\
> +	[EFC_EVT_NODE_ATTACH_OK]	= "EFC_EVT_NODE_ATTACH_OK",	\
> +	[EFC_EVT_NODE_ATTACH_FAIL]	= "EFC_EVT_NODE_ATTACH_FAIL",	\
> +	[EFC_EVT_NODE_FREE_OK]		= "EFC_EVT_NODE_FREE_OK",	\
> +	[EFC_EVT_NODE_FREE_FAIL]	= "EFC_EVT_NODE_FREE_FAIL",	\
> +	[EFC_EVT_ELS_FRAME]		= "EFC_EVT_ELS_FRAME",		\
> +	[EFC_EVT_ELS_REQ_TIMEOUT]	= "EFC_EVT_ELS_REQ_TIMEOUT",	\
> +	[EFC_EVT_ELS_REQ_ABORTED]	= "EFC_EVT_ELS_REQ_ABORTED",	\
> +	[EFC_EVT_ABORT_ELS]		= "EFC_EVT_ABORT_ELS",		\
> +	[EFC_EVT_ELS_ABORT_CMPL]	= "EFC_EVT_ELS_ABORT_CMPL",	\
> +	[EFC_EVT_ABTS_RCVD]		= "EFC_EVT_ABTS_RCVD",		\
> +	[EFC_EVT_NODE_MISSING]		= "EFC_EVT_NODE_MISSING",	\
> +	[EFC_EVT_NODE_REFOUND]		= "EFC_EVT_NODE_REFOUND",	\
> +	[EFC_EVT_SHUTDOWN_IMPLICIT_LOGO] = "EFC_EVT_SHUTDOWN_IMPLICIT_LOGO",\
> +	[EFC_EVT_SHUTDOWN_EXPLICIT_LOGO] = "EFC_EVT_SHUTDOWN_EXPLICIT_LOGO",\
> +	[EFC_EVT_PLOGI_RCVD]		= "EFC_EVT_PLOGI_RCVD",		\
> +	[EFC_EVT_FLOGI_RCVD]		= "EFC_EVT_FLOGI_RCVD",		\
> +	[EFC_EVT_LOGO_RCVD]		= "EFC_EVT_LOGO_RCVD",		\
> +	[EFC_EVT_PRLI_RCVD]		= "EFC_EVT_PRLI_RCVD",		\
> +	[EFC_EVT_PRLO_RCVD]		= "EFC_EVT_PRLO_RCVD",		\
> +	[EFC_EVT_PDISC_RCVD]		= "EFC_EVT_PDISC_RCVD",		\
> +	[EFC_EVT_FDISC_RCVD]		= "EFC_EVT_FDISC_RCVD",		\
> +	[EFC_EVT_ADISC_RCVD]		= "EFC_EVT_ADISC_RCVD",		\
> +	[EFC_EVT_RSCN_RCVD]		= "EFC_EVT_RSCN_RCVD",		\
> +	[EFC_EVT_SCR_RCVD]		= "EFC_EVT_SCR_RCVD",		\
> +	[EFC_EVT_ELS_RCVD]		= "EFC_EVT_ELS_RCVD",		\
> +	[EFC_EVT_FCP_CMD_RCVD]		= "EFC_EVT_FCP_CMD_RCVD",	\
> +	[EFC_EVT_NODE_DEL_INI_COMPLETE]	= "EFC_EVT_NODE_DEL_INI_COMPLETE",\
> +	[EFC_EVT_NODE_DEL_TGT_COMPLETE]	= "EFC_EVT_NODE_DEL_TGT_COMPLETE",\
> +	[EFC_EVT_LAST]			= "EFC_EVT_LAST",		\
> +}

The final array event_name has 803 entries and only 63 entries
are filled. Yep, I really checked this :)

> +int
> +efc_sm_post_event(struct efc_sm_ctx *ctx,
> +		  enum efc_sm_event evt, void *data);
> +void
> +efc_sm_transition(struct efc_sm_ctx *ctx,
> +		  void *(*state)(struct efc_sm_ctx *ctx,
> +				 enum efc_sm_event evt, void *arg),
> +		  void *data);
> +void efc_sm_disable(struct efc_sm_ctx *ctx);
> +const char *efc_sm_event_name(enum efc_sm_event evt);
> +
> +#endif /* ! _EFC_SM_H */
> -- 
> 2.16.4
> 

Thanks,
Daniel