From 4f6a57c23b1e002487159791feef7d54b725bfa6 Mon Sep 17 00:00:00 2001 From: "Ahmed S. Darwish" Date: Thu, 26 Nov 2020 14:29:44 +0100 Subject: [PATCH] scsi: qla2xxx: Remove in_interrupt() from qla83xx-specific code 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". Link: https://lore.kernel.org/r/20201126132952.2287996-7-bigeasy@linutronix.de Cc: Nilesh Javali Cc: GR-QLogic-Storage-Upstream@marvell.com Reviewed-by: Himanshu Madhani Reviewed-by: Daniel Wagner Signed-off-by: Ahmed S. Darwish Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Martin K. Petersen --- 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 f9c8ae9d669e..2a8e065b192c 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 @@ retry_lockid: 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 @@ exit: 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 @@ retry_lock: /* 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 @@ retry_unlock: /* 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 @@ retry_unlock: } } 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 @@ retry_unlock2: 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);