[PATCH 06/14] scsi: qla2xxx: init/os: Remove in_interrupt().

Sebastian Andrzej Siewior
2020-11-26T13:30:36Z

From: "Ahmed S. Darwish" <a.darwish@linutronix.de>

qla83xx_wait_logic() is used to control the frequency of device IDC lock
retries. If in_interrupt() is true, it does 20 loops of cpu_relax().
Otherwise, it sleeps for 100ms and yields the CPU.

While in_interrupt() is ill-defined and does not provide what the name
suggests, it is not needed here: that qla83xx_wait_logic() is exclusively
called by qla83xx_idc_lock() / unlock(), and they always run from
process context. Below is an analysis of all the idc lock/unlock callers,
in order of appearance:

- qla_os.c:
qla83xx_nic_core_unrecoverable_work(),
qla83xx_idc_state_handler_work(),
qla83xx_nic_core_reset_work(),
qla83xx_service_idc_aen(), all workqueue context

- qla_os.c: qla83xx_check_nic_core_fw_alive(), has msleep()

- qla_os.c: qla83xx_set_drv_presence(), called once from
qla2x00_abort_isp(), which is bound to process-context ->abort_isp()
hook. It also invokes wait_for_completion_timeout() through the
chain qla2x00_configure_hba() => qla24xx_link_initialize() =>
qla2x00_mailbox_command().

- qla_os.c: qla83xx_clear_drv_presence(), which is called from
qla2x00_abort_isp() discussed above, and from qla2x00_remove_one()
which is PCI process-context ->remove() hook.

- qla_os.c: qla83xx_need_reset_handler(), has a one second msleep() in
a loop.

- qla_os.c: qla83xx_device_bootstrap(), called only by
qla83xx_idc_state_handler(), which has multiple msleep()
invocations.

- qla_os.c: qla83xx_idc_state_handler(), multiple msleep()
invocations.

- qla_attr.c: qla2x00_sysfs_write_reset(), sysfs bin_attribute
->write() hook, process context

- qla_init.c: qla83xx_nic_core_fw_load()
=> qla_init.c: qla2x00_initialize_adapter()
=> bound to isp_operations ->initialize_adapter() hook
** => qla_os.c: qla2x00_probe_one(), PCI ->probe() process ctx

- qla_init.c: qla83xx_initiating_reset(), msleep() in a loop.

- qla_init.c: qla83xx_nic_core_reset(), called by
qla83xx_nic_core_reset_work(), workqueue context.

Remove the in_interrupt() check, and thus replace the entirety of
qla83xx_wait_logic() with an msleep(QLA83XX_WAIT_LOGIC_MS).

Mark qla83xx_idc_lock() / unlock() with "Context: task, can sleep".

Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Nilesh Javali <njavali@marvell.com>
Cc: GR-QLogic-Storage-Upstream@marvell.com
---
drivers/scsi/qla2xxx/qla_os.c | 43 ++++++++++++++++-------------------
1 file changed, 19 insertions(+), 24 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index f9c8ae9d669ef..2a8e065b192c3 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -5619,25 +5619,10 @@ qla83xx_service_idc_aen(struct work_struct *work)
}
}

-static void
-qla83xx_wait_logic(void)
-{
- int i;
-
- /* Yield CPU */
- if (!in_interrupt()) {
- /*
- * Wait about 200ms before retrying again.
- * This controls the number of retries for single
- * lock operation.
- */
- msleep(100);
- schedule();
- } else {
- for (i = 0; i < 20; i++)
- cpu_relax(); /* This a nop instr on i386 */
- }
-}
+/*
+ * Control the frequency of IDC lock retries
+ */
+#define QLA83XX_WAIT_LOGIC_MS 100

static int
qla83xx_force_lock_recovery(scsi_qla_host_t *base_vha)
@@ -5727,7 +5712,7 @@ qla83xx_idc_lock_recovery(scsi_qla_host_t *base_vha)
goto exit;

if (o_drv_lockid == n_drv_lockid) {
- qla83xx_wait_logic();
+ msleep(QLA83XX_WAIT_LOGIC_MS);
goto retry_lockid;
} else
return QLA_SUCCESS;
@@ -5736,6 +5721,9 @@ qla83xx_idc_lock_recovery(scsi_qla_host_t *base_vha)
return rval;
}

+/*
+ * Context: task, can sleep
+ */
void
qla83xx_idc_lock(scsi_qla_host_t *base_vha, uint16_t requester_id)
{
@@ -5743,6 +5731,8 @@ qla83xx_idc_lock(scsi_qla_host_t *base_vha, uint16_t requester_id)
uint32_t lock_owner;
struct qla_hw_data *ha = base_vha->hw;

+ might_sleep();
+
/* IDC-lock implementation using driver-lock/lock-id remote registers */
retry_lock:
if (qla83xx_rd_reg(base_vha, QLA83XX_DRIVER_LOCK, &data)
@@ -5761,7 +5751,7 @@ qla83xx_idc_lock(scsi_qla_host_t *base_vha, uint16_t requester_id)
/* Retry/Perform IDC-Lock recovery */
if (qla83xx_idc_lock_recovery(base_vha)
== QLA_SUCCESS) {
- qla83xx_wait_logic();
+ msleep(QLA83XX_WAIT_LOGIC_MS);
goto retry_lock;
} else
ql_log(ql_log_warn, base_vha, 0xb075,
@@ -6259,6 +6249,9 @@ void qla24xx_process_purex_list(struct purex_list *list)
}
}

+/*
+ * Context: task, can sleep
+ */
void
qla83xx_idc_unlock(scsi_qla_host_t *base_vha, uint16_t requester_id)
{
@@ -6269,6 +6262,8 @@ qla83xx_idc_unlock(scsi_qla_host_t *base_vha, uint16_t requester_id)
uint32_t data;
struct qla_hw_data *ha = base_vha->hw;

+ might_sleep();
+
/* IDC-unlock implementation using driver-unlock/lock-id
* remote registers
*/
@@ -6284,7 +6279,7 @@ qla83xx_idc_unlock(scsi_qla_host_t *base_vha, uint16_t requester_id)
/* SV: XXX: IDC unlock retrying needed here? */

/* Retry for IDC-unlock */
- qla83xx_wait_logic();
+ msleep(QLA83XX_WAIT_LOGIC_MS);
retry++;
ql_dbg(ql_dbg_p3p, base_vha, 0xb064,
"Failed to release IDC lock, retrying=%d\n", retry);
@@ -6292,7 +6287,7 @@ qla83xx_idc_unlock(scsi_qla_host_t *base_vha, uint16_t requester_id)
}
} else if (retry < 10) {
/* Retry for IDC-unlock */
- qla83xx_wait_logic();
+ msleep(QLA83XX_WAIT_LOGIC_MS);
retry++;
ql_dbg(ql_dbg_p3p, base_vha, 0xb065,
"Failed to read drv-lockid, retrying=%d\n", retry);
@@ -6308,7 +6303,7 @@ qla83xx_idc_unlock(scsi_qla_host_t *base_vha, uint16_t requester_id)
if (qla83xx_access_control(base_vha, options, 0, 0, NULL)) {
if (retry < 10) {
/* Retry for IDC-unlock */
- qla83xx_wait_logic();
+ msleep(QLA83XX_WAIT_LOGIC_MS);
retry++;
ql_dbg(ql_dbg_p3p, base_vha, 0xb066,
"Failed to release IDC lock, retrying=%d\n", retry);
--
2.29.2