[PATCH AUTOSEL 5.14 14/99] scsi: lpfc: Clear outstanding active mailbox during PCI function reset

Sasha Levin
2021-09-10T00:16:46Z

From: James Smart <jsmart2021@gmail.com>

[ Upstream commit a9978e3978406ef5e35870b10e677cf75a2620b6 ]

Mailbox commands sent via ioctl/bsg from user applications may be
interrupted from processing by a concurrently triggered PCI function
reset. The command will not generate a completion due to the reset. This
results in a user application hang waiting for the mailbox command to
complete.

Resolve by changing the function reset handler to detect that there was an
outstanding mailbox command and simulate a mailbox completion. Add some
additional debug when a mailbox command times out.

Link: https://lore.kernel.org/r/20210707184351.67872-13-jsmart2021@gmail.com
Co-developed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/scsi/lpfc/lpfc_init.c | 11 ++++++++++-
drivers/scsi/lpfc/lpfc_sli.c | 32 ++++++++++++++++++++++++++++++--
2 files changed, 40 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index c4235699a123..221f22a026e5 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -1852,6 +1852,7 @@ lpfc_sli4_port_sta_fn_reset(struct lpfc_hba *phba, int mbx_action,
{
int rc;
uint32_t intr_mode;
+ LPFC_MBOXQ_t *mboxq;

if (bf_get(lpfc_sli_intf_if_type, &phba->sli4_hba.sli_intf) >=
LPFC_SLI_INTF_IF_TYPE_2) {
@@ -1871,11 +1872,19 @@ lpfc_sli4_port_sta_fn_reset(struct lpfc_hba *phba, int mbx_action,
"Recovery...\n");

/* If we are no wait, the HBA has been reset and is not
- * functional, thus we should clear LPFC_SLI_ACTIVE flag.
+ * functional, thus we should clear
+ * (LPFC_SLI_ACTIVE | LPFC_SLI_MBOX_ACTIVE) flags.
*/
if (mbx_action == LPFC_MBX_NO_WAIT) {
spin_lock_irq(&phba->hbalock);
phba->sli.sli_flag &= ~LPFC_SLI_ACTIVE;
+ if (phba->sli.mbox_active) {
+ mboxq = phba->sli.mbox_active;
+ mboxq->u.mb.mbxStatus = MBX_NOT_FINISHED;
+ __lpfc_mbox_cmpl_put(phba, mboxq);
+ phba->sli.sli_flag &= ~LPFC_SLI_MBOX_ACTIVE;
+ phba->sli.mbox_active = NULL;
+ }
spin_unlock_irq(&phba->hbalock);
}

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index f530d8fe7a8c..b6f58843c77a 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -8790,8 +8790,11 @@ static int
lpfc_sli4_async_mbox_block(struct lpfc_hba *phba)
{
struct lpfc_sli *psli = &phba->sli;
+ LPFC_MBOXQ_t *mboxq;
int rc = 0;
unsigned long timeout = 0;
+ u32 sli_flag;
+ u8 cmd, subsys, opcode;

/* Mark the asynchronous mailbox command posting as blocked */
spin_lock_irq(&phba->hbalock);
@@ -8809,12 +8812,37 @@ lpfc_sli4_async_mbox_block(struct lpfc_hba *phba)
if (timeout)
lpfc_sli4_process_missed_mbox_completions(phba);

- /* Wait for the outstnading mailbox command to complete */
+ /* Wait for the outstanding mailbox command to complete */
while (phba->sli.mbox_active) {
/* Check active mailbox complete status every 2ms */
msleep(2);
if (time_after(jiffies, timeout)) {
- /* Timeout, marked the outstanding cmd not complete */
+ /* Timeout, mark the outstanding cmd not complete */
+
+ /* Sanity check sli.mbox_active has not completed or
+ * cancelled from another context during last 2ms sleep,
+ * so take hbalock to be sure before logging.
+ */
+ spin_lock_irq(&phba->hbalock);
+ if (phba->sli.mbox_active) {
+ mboxq = phba->sli.mbox_active;
+ cmd = mboxq->u.mb.mbxCommand;
+ subsys = lpfc_sli_config_mbox_subsys_get(phba,
+ mboxq);
+ opcode = lpfc_sli_config_mbox_opcode_get(phba,
+ mboxq);
+ sli_flag = psli->sli_flag;
+ spin_unlock_irq(&phba->hbalock);
+ lpfc_printf_log(phba, KERN_ERR, LOG_TRACE_EVENT,
+ "2352 Mailbox command x%x "
+ "(x%x/x%x) sli_flag x%x could "
+ "not complete\n",
+ cmd, subsys, opcode,
+ sli_flag);
+ } else {
+ spin_unlock_irq(&phba->hbalock);
+ }
+
rc = 1;
break;
}
--
2.30.2