scsi: lpfc: Fix driver release of fw-logging buffers

On driver termination, after the driver stops fw logging by writing a
register on the chip, the driver immediately unmaps and frees the logging
buffer, without confirming in any way that the chip has received the write
and terminated the logging. As termination on the chip is not immediate,
the chip may issue a dma request to the now unmapped dma buffer, resulting
in a iommu fault.

Change the driver to receive a confirmation that logging ahs been
terminated. As the driver always issues an SLI reset with the device as
part of shutdown, and as part of that is receiving confirmation that the
reset is complete - the driver was modified to perform the write to disable
fw logging prior to the SLI reset and only free the fw log buffer after the
SLI reset is complete. That guarantees use of the fw log buffer is fully
terminated when it is unmapped.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 760b819f690a..3826a32eec20 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -6198,6 +6198,25 @@ lpfc_set_features(struct lpfc_hba *phba, LPFC_MBOXQ_t *mbox,
 }
 
 /**
+ * lpfc_ras_stop_fwlog: Disable FW logging by the adapter
+ * @phba: Pointer to HBA context object.
+ *
+ * Disable FW logging into host memory on the adapter. To
+ * be done before reading logs from the host memory.
+ **/
+void
+lpfc_ras_stop_fwlog(struct lpfc_hba *phba)
+{
+	struct lpfc_ras_fwlog *ras_fwlog = &phba->ras_fwlog;
+
+	ras_fwlog->ras_active = false;
+
+	/* Disable FW logging to host memory */
+	writel(LPFC_CTL_PDEV_CTL_DDL_RAS,
+	       phba->sli4_hba.conf_regs_memmap_p + LPFC_CTL_PDEV_CTL_OFFSET);
+}
+
+/**
  * lpfc_sli4_ras_dma_free - Free memory allocated for FW logging.
  * @phba: Pointer to HBA context object.
  *