scsi: bfa: Fix function pointer type mismatch for state machines

The bfa driver is full of state machines and a generic abstraction layer
for them. This relies on casting function pointers, but that is no longer
allowed when CONFIG_CFI_CLANG is enabled and causes a huge number of
warnings like:

drivers/scsi/bfa/bfad.c:169:3: error: cast from 'void (*)(struct bfad_s *, enum bfad_sm_event)' to 'bfa_sm_t' (aka 'void (*)(void *, int)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
                bfa_sm_set_state(bfad, bfad_sm_created);
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Rework the mechanism to no longer require the function pointer casts, by
having separate types for each individual state machine. This in turn
requires moving the enum definitions for each state machine into the header
files in order to define the typedef.

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20240222124433.2046570-2-arnd@kernel.org
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: arndb

drivers/scsi/bfa/bfa.h

@@ -215,8 +215,27 @@ struct bfa_faa_args_s {
 	bfa_boolean_t		busy;
 };
 
+/*
+ * IOCFC state machine definitions/declarations
+ */
+enum iocfc_event {
+	IOCFC_E_INIT		= 1,	/* IOCFC init request		*/
+	IOCFC_E_START		= 2,	/* IOCFC mod start request	*/
+	IOCFC_E_STOP		= 3,	/* IOCFC stop request		*/
+	IOCFC_E_ENABLE		= 4,	/* IOCFC enable request		*/
+	IOCFC_E_DISABLE		= 5,	/* IOCFC disable request	*/
+	IOCFC_E_IOC_ENABLED	= 6,	/* IOC enabled message		*/
+	IOCFC_E_IOC_DISABLED	= 7,	/* IOC disabled message		*/
+	IOCFC_E_IOC_FAILED	= 8,	/* failure notice by IOC sm	*/
+	IOCFC_E_DCONF_DONE	= 9,	/* dconf read/write done	*/
+	IOCFC_E_CFG_DONE	= 10,	/* IOCFC config complete	*/
+};
+
+struct bfa_iocfc_s;
+typedef void (*bfa_iocfs_fsm_t)(struct bfa_iocfc_s *, enum iocfc_event);
+
 struct bfa_iocfc_s {
-	bfa_fsm_t		fsm;
+	bfa_iocfs_fsm_t		fsm;
 	struct bfa_s		*bfa;
 	struct bfa_iocfc_cfg_s	cfg;
 	u32		req_cq_pi[BFI_IOC_MAX_CQS];

drivers/scsi/bfa/bfa_cs.h

@@ -187,10 +187,10 @@ typedef void (*bfa_sm_t)(void *sm, int event);
 #define bfa_sm_state_decl(oc, st, otype, etype)		\
 	static void oc ## _sm_ ## st(otype * fsm, etype event)
 
-#define bfa_sm_set_state(_sm, _state)	((_sm)->sm = (bfa_sm_t)(_state))
+#define bfa_sm_set_state(_sm, _state)	((_sm)->sm = (_state))
 #define bfa_sm_send_event(_sm, _event)	((_sm)->sm((_sm), (_event)))
 #define bfa_sm_get_state(_sm)		((_sm)->sm)
-#define bfa_sm_cmp_state(_sm, _state)	((_sm)->sm == (bfa_sm_t)(_state))
+#define bfa_sm_cmp_state(_sm, _state)	((_sm)->sm == (_state))
 
 /*
  * For converting from state machine function to state encoding.
@@ -200,7 +200,7 @@ struct bfa_sm_table_s {
 	int		state;	/*  state machine encoding	*/
 	char		*name;	/*  state name for display	*/
 };
-#define BFA_SM(_sm)	((bfa_sm_t)(_sm))
+#define BFA_SM(_sm)	(_sm)
 
 /*
  * State machine with entry actions.
@@ -218,24 +218,13 @@ typedef void (*bfa_fsm_t)(void *fsm, int event);
 	static void oc ## _sm_ ## st ## _entry(otype * fsm)
 
 #define bfa_fsm_set_state(_fsm, _state) do {	\
-	(_fsm)->fsm = (bfa_fsm_t)(_state);      \
+	(_fsm)->fsm = (_state);      \
 	_state ## _entry(_fsm);      \
 } while (0)
 
 #define bfa_fsm_send_event(_fsm, _event)	((_fsm)->fsm((_fsm), (_event)))
 #define bfa_fsm_get_state(_fsm)			((_fsm)->fsm)
-#define bfa_fsm_cmp_state(_fsm, _state)		\
-	((_fsm)->fsm == (bfa_fsm_t)(_state))
-
-static inline int
-bfa_sm_to_state(struct bfa_sm_table_s *smt, bfa_sm_t sm)
-{
-	int	i = 0;
-
-	while (smt[i].sm && smt[i].sm != sm)
-		i++;
-	return smt[i].state;
-}
+#define bfa_fsm_cmp_state(_fsm, _state)		((_fsm)->fsm == (_state))
 
 /*
  * @ Generic wait counter.

drivers/scsi/bfa/bfa_fcpim.c

@@ -64,21 +64,6 @@ enum bfa_ioim_lm_ua_status {
 	BFA_IOIM_LM_UA_SET = 1,
 };
 
-/*
- *  itnim state machine event
- */
-enum bfa_itnim_event {
-	BFA_ITNIM_SM_CREATE = 1,	/*  itnim is created */
-	BFA_ITNIM_SM_ONLINE = 2,	/*  itnim is online */
-	BFA_ITNIM_SM_OFFLINE = 3,	/*  itnim is offline */
-	BFA_ITNIM_SM_FWRSP = 4,		/*  firmware response */
-	BFA_ITNIM_SM_DELETE = 5,	/*  deleting an existing itnim */
-	BFA_ITNIM_SM_CLEANUP = 6,	/*  IO cleanup completion */
-	BFA_ITNIM_SM_SLER = 7,		/*  second level error recovery */
-	BFA_ITNIM_SM_HWFAIL = 8,	/*  IOC h/w failure event */
-	BFA_ITNIM_SM_QRESUME = 9,	/*  queue space available */
-};
-
 /*
  *  BFA IOIM related definitions
  */
@@ -98,30 +83,6 @@ enum bfa_itnim_event {
 		(__fcpim)->profile_start(__ioim);			\
 } while (0)
 
-/*
- * IO state machine events
- */
-enum bfa_ioim_event {
-	BFA_IOIM_SM_START	= 1,	/*  io start request from host */
-	BFA_IOIM_SM_COMP_GOOD	= 2,	/*  io good comp, resource free */
-	BFA_IOIM_SM_COMP	= 3,	/*  io comp, resource is free */
-	BFA_IOIM_SM_COMP_UTAG	= 4,	/*  io comp, resource is free */
-	BFA_IOIM_SM_DONE	= 5,	/*  io comp, resource not free */
-	BFA_IOIM_SM_FREE	= 6,	/*  io resource is freed */
-	BFA_IOIM_SM_ABORT	= 7,	/*  abort request from scsi stack */
-	BFA_IOIM_SM_ABORT_COMP	= 8,	/*  abort from f/w */
-	BFA_IOIM_SM_ABORT_DONE	= 9,	/*  abort completion from f/w */
-	BFA_IOIM_SM_QRESUME	= 10,	/*  CQ space available to queue IO */
-	BFA_IOIM_SM_SGALLOCED	= 11,	/*  SG page allocation successful */
-	BFA_IOIM_SM_SQRETRY	= 12,	/*  sequence recovery retry */
-	BFA_IOIM_SM_HCB		= 13,	/*  bfa callback complete */
-	BFA_IOIM_SM_CLEANUP	= 14,	/*  IO cleanup from itnim */
-	BFA_IOIM_SM_TMSTART	= 15,	/*  IO cleanup from tskim */
-	BFA_IOIM_SM_TMDONE	= 16,	/*  IO cleanup from tskim */
-	BFA_IOIM_SM_HWFAIL	= 17,	/*  IOC h/w failure event */
-	BFA_IOIM_SM_IOTOV	= 18,	/*  ITN offline TOV */
-};
-
 
 /*
  *  BFA TSKIM related definitions
@@ -141,18 +102,6 @@ enum bfa_ioim_event {
 } while (0)
 
 
-enum bfa_tskim_event {
-	BFA_TSKIM_SM_START	= 1,	/*  TM command start		*/
-	BFA_TSKIM_SM_DONE	= 2,	/*  TM completion		*/
-	BFA_TSKIM_SM_QRESUME	= 3,	/*  resume after qfull		*/
-	BFA_TSKIM_SM_HWFAIL	= 5,	/*  IOC h/w failure event	*/
-	BFA_TSKIM_SM_HCB	= 6,	/*  BFA callback completion	*/
-	BFA_TSKIM_SM_IOS_DONE	= 7,	/*  IO and sub TM completions	*/
-	BFA_TSKIM_SM_CLEANUP	= 8,	/*  TM cleanup on ITN offline	*/
-	BFA_TSKIM_SM_CLEANUP_DONE = 9,	/*  TM abort completion	*/
-	BFA_TSKIM_SM_UTAG	= 10,	/*  TM completion unknown tag  */
-};
-
 /*
  * forward declaration for BFA ITNIM functions
  */

drivers/scsi/bfa/bfa_fcpim.h

@@ -154,12 +154,39 @@ struct bfa_fcp_mod_s {
 	int			throttle_update_required;
 };
 
+/*
+ * IO state machine events
+ */
+enum bfa_ioim_event {
+	BFA_IOIM_SM_START	= 1,	/*  io start request from host */
+	BFA_IOIM_SM_COMP_GOOD	= 2,	/*  io good comp, resource free */
+	BFA_IOIM_SM_COMP	= 3,	/*  io comp, resource is free */
+	BFA_IOIM_SM_COMP_UTAG	= 4,	/*  io comp, resource is free */
+	BFA_IOIM_SM_DONE	= 5,	/*  io comp, resource not free */
+	BFA_IOIM_SM_FREE	= 6,	/*  io resource is freed */
+	BFA_IOIM_SM_ABORT	= 7,	/*  abort request from scsi stack */
+	BFA_IOIM_SM_ABORT_COMP	= 8,	/*  abort from f/w */
+	BFA_IOIM_SM_ABORT_DONE	= 9,	/*  abort completion from f/w */
+	BFA_IOIM_SM_QRESUME	= 10,	/*  CQ space available to queue IO */
+	BFA_IOIM_SM_SGALLOCED	= 11,	/*  SG page allocation successful */
+	BFA_IOIM_SM_SQRETRY	= 12,	/*  sequence recovery retry */
+	BFA_IOIM_SM_HCB		= 13,	/*  bfa callback complete */
+	BFA_IOIM_SM_CLEANUP	= 14,	/*  IO cleanup from itnim */
+	BFA_IOIM_SM_TMSTART	= 15,	/*  IO cleanup from tskim */
+	BFA_IOIM_SM_TMDONE	= 16,	/*  IO cleanup from tskim */
+	BFA_IOIM_SM_HWFAIL	= 17,	/*  IOC h/w failure event */
+	BFA_IOIM_SM_IOTOV	= 18,	/*  ITN offline TOV */
+};
+
+struct bfa_ioim_s;
+typedef void (*bfa_ioim_sm_t)(struct bfa_ioim_s *, enum bfa_ioim_event);
+
 /*
  * BFA IO (initiator mode)
  */
 struct bfa_ioim_s {
 	struct list_head	qe;		/*  queue elememt	*/
-	bfa_sm_t		sm;		/*  BFA ioim state machine */
+	bfa_ioim_sm_t		sm;		/*  BFA ioim state machine */
 	struct bfa_s		*bfa;		/*  BFA module	*/
 	struct bfa_fcpim_s	*fcpim;		/*  parent fcpim module */
 	struct bfa_itnim_s	*itnim;		/*  i-t-n nexus for this IO  */
@@ -186,12 +213,27 @@ struct bfa_ioim_sp_s {
 	struct bfa_tskim_s	*tskim;		/*  Relevant TM cmd	*/
 };
 
+enum bfa_tskim_event {
+	BFA_TSKIM_SM_START	= 1,	/*  TM command start		*/
+	BFA_TSKIM_SM_DONE	= 2,	/*  TM completion		*/
+	BFA_TSKIM_SM_QRESUME	= 3,	/*  resume after qfull		*/
+	BFA_TSKIM_SM_HWFAIL	= 5,	/*  IOC h/w failure event	*/
+	BFA_TSKIM_SM_HCB	= 6,	/*  BFA callback completion	*/
+	BFA_TSKIM_SM_IOS_DONE	= 7,	/*  IO and sub TM completions	*/
+	BFA_TSKIM_SM_CLEANUP	= 8,	/*  TM cleanup on ITN offline	*/
+	BFA_TSKIM_SM_CLEANUP_DONE = 9,	/*  TM abort completion	*/
+	BFA_TSKIM_SM_UTAG	= 10,	/*  TM completion unknown tag  */
+};
+
+struct bfa_tskim_s;
+typedef void (*bfa_tskim_sm_t)(struct bfa_tskim_s *, enum bfa_tskim_event);
+
 /*
  * BFA Task management command (initiator mode)
  */
 struct bfa_tskim_s {
 	struct list_head	qe;
-	bfa_sm_t		sm;
+	bfa_tskim_sm_t		sm;
 	struct bfa_s		*bfa;	/*  BFA module  */
 	struct bfa_fcpim_s	*fcpim;	/*  parent fcpim module	*/
 	struct bfa_itnim_s	*itnim;	/*  i-t-n nexus for this IO  */
@@ -208,12 +250,30 @@ struct bfa_tskim_s {
 	enum bfi_tskim_status   tsk_status;  /*  TM status	*/
 };
 
+/*
+ *  itnim state machine event
+ */
+enum bfa_itnim_event {
+	BFA_ITNIM_SM_CREATE = 1,	/*  itnim is created */
+	BFA_ITNIM_SM_ONLINE = 2,	/*  itnim is online */
+	BFA_ITNIM_SM_OFFLINE = 3,	/*  itnim is offline */
+	BFA_ITNIM_SM_FWRSP = 4,		/*  firmware response */
+	BFA_ITNIM_SM_DELETE = 5,	/*  deleting an existing itnim */
+	BFA_ITNIM_SM_CLEANUP = 6,	/*  IO cleanup completion */
+	BFA_ITNIM_SM_SLER = 7,		/*  second level error recovery */
+	BFA_ITNIM_SM_HWFAIL = 8,	/*  IOC h/w failure event */
+	BFA_ITNIM_SM_QRESUME = 9,	/*  queue space available */
+};
+
+struct bfa_itnim_s;
+typedef void (*bfa_itnim_sm_t)(struct bfa_itnim_s *, enum bfa_itnim_event);
+
 /*
  * BFA i-t-n (initiator mode)
  */
 struct bfa_itnim_s {
 	struct list_head	qe;	/*  queue element	*/
-	bfa_sm_t		sm;	/*  i-t-n im BFA state machine  */
+	bfa_itnim_sm_t		sm;	/*  i-t-n im BFA state machine  */
 	struct bfa_s		*bfa;	/*  bfa instance	*/
 	struct bfa_rport_s	*rport;	/*  bfa rport	*/
 	void			*ditn;	/*  driver i-t-n structure	*/