scsi: lpfc: Define types in a union for generic void *context3 ptr

In LPFC_MBOXQ_t, the void *context3 ptr is used for various paths.  It is
treated as a generic pointer, and is type casted during its usage.

The issue with this is that it can sometimes get confusing when reading
code as to what the context3 ptr is being used for and mistakenly be reused
in a different context.

Rename context3 to ctx_u, and declare it as a union of defined ptr types.
From now on, the ctx_u ptr may be used only if users define the use case
type.

Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20240305200503.57317-11-justintee8345@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 6 insertions, 9 deletions

diff --git a/drivers/scsi/lpfc/lpfc_mbox.c b/drivers/scsi/lpfc/lpfc_mbox.c
index eaa3f89458ec..e98f1c2b2220 100644
--- a/drivers/scsi/lpfc/lpfc_mbox.c
+++ b/drivers/scsi/lpfc/lpfc_mbox.c
@@ -1809,7 +1809,7 @@ lpfc_sli4_mbox_cmd_free(struct lpfc_hba *phba, struct lpfcMboxq *mbox)
 	}
 	/* Reinitialize the context pointers to avoid stale usage. */
 	mbox->ctx_buf = NULL;
-	mbox->context3 = NULL;
+	memset(&mbox->ctx_u, 0, sizeof(mbox->ctx_u));
 	kfree(mbox->sge_array);
 	/* Finally, free the mailbox command itself */
 	mempool_free(mbox, phba->mbox_mem_pool);
@@ -2359,8 +2359,7 @@ lpfc_mbx_cmpl_rdp_link_stat(struct lpfc_hba *phba, LPFC_MBOXQ_t *mboxq)
 {
 	MAILBOX_t *mb;
 	int rc = FAILURE;
-	struct lpfc_rdp_context *rdp_context =
-			(struct lpfc_rdp_context *)(mboxq->context3);
+	struct lpfc_rdp_context *rdp_context = mboxq->ctx_u.rdp;
 
 	mb = &mboxq->u.mb;
 	if (mb->mbxStatus)
@@ -2379,8 +2378,7 @@ static void
 lpfc_mbx_cmpl_rdp_page_a2(struct lpfc_hba *phba, LPFC_MBOXQ_t *mbox)
 {
 	struct lpfc_dmabuf *mp = mbox->ctx_buf;
-	struct lpfc_rdp_context *rdp_context =
-			(struct lpfc_rdp_context *)(mbox->context3);
+	struct lpfc_rdp_context *rdp_context = mbox->ctx_u.rdp;
 
 	if (bf_get(lpfc_mqe_status, &mbox->u.mqe))
 		goto error_mbox_free;
@@ -2394,7 +2392,7 @@ lpfc_mbx_cmpl_rdp_page_a2(struct lpfc_hba *phba, LPFC_MBOXQ_t *mbox)
 	/* Save the dma buffer for cleanup in the final completion. */
 	mbox->ctx_buf = mp;
 	mbox->mbox_cmpl = lpfc_mbx_cmpl_rdp_link_stat;
-	mbox->context3 = (struct lpfc_rdp_context *)rdp_context;
+	mbox->ctx_u.rdp = rdp_context;
 	if (lpfc_sli_issue_mbox(phba, mbox, MBX_NOWAIT) == MBX_NOT_FINISHED)
 		goto error_mbox_free;
 
@@ -2410,8 +2408,7 @@ lpfc_mbx_cmpl_rdp_page_a0(struct lpfc_hba *phba, LPFC_MBOXQ_t *mbox)
 {
 	int rc;
 	struct lpfc_dmabuf *mp = mbox->ctx_buf;
-	struct lpfc_rdp_context *rdp_context =
-			(struct lpfc_rdp_context *)(mbox->context3);
+	struct lpfc_rdp_context *rdp_context = mbox->ctx_u.rdp;
 
 	if (bf_get(lpfc_mqe_status, &mbox->u.mqe))
 		goto error;
@@ -2441,7 +2438,7 @@ lpfc_mbx_cmpl_rdp_page_a0(struct lpfc_hba *phba, LPFC_MBOXQ_t *mbox)
 	mbox->u.mqe.un.mem_dump_type3.addr_hi = putPaddrHigh(mp->phys);
 
 	mbox->mbox_cmpl = lpfc_mbx_cmpl_rdp_page_a2;
-	mbox->context3 = (struct lpfc_rdp_context *)rdp_context;
+	mbox->ctx_u.rdp = rdp_context;
 	rc = lpfc_sli_issue_mbox(phba, mbox, MBX_NOWAIT);
 	if (rc == MBX_NOT_FINISHED)
 		goto error;