| Message ID | 20201126132952.2287996-5-bigeasy@linutronix.de (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | scsi: Remove in_interrupt() usage. | expand |
On Thu, Nov 26, 2020 at 02:29:42PM +0100, Sebastian Andrzej Siewior wrote: > From: "Ahmed S. Darwish" <a.darwish@linutronix.de> > > qla82xx_idc_lock() spins on a certain hardware state until it's updated. At > the end of each spin, if in_interrupt() is true, it does 20 loops of > cpu_relax(). Otherwise, it yields the CPU. > > While in_interrupt() is ill-defined and does not provide what the name > suggests, it is not needed here: qla82xx_idc_lock() is always called > from process context. Below is an analysis of its callers, in order of > appearance: > > - qla_nx.c: qla82xx_device_bootstrap(), only called by > qla82xx_device_state_handler(), has multiple msleep()s. > > - qla_nx.c: qla82xx_need_qsnt_handler(), has one second msleep() > > - qla_nx.c: qla82xx_wait_for_state_change(), one second msleep() > > - qla_nx.c: qla82xx_need_reset_handler(), can sleep up to 10 seconds > > - qla_nx.c: qla82xx_device_state_handler(), has multiple msleep()s > > - qla_nx.c: qla82xx_abort_isp(), if it's a qla82xx controller, calls > qla82xx_device_state_handler(), which sleeps. It's also bound to > isp_operations ->abort_isp() hook, where all the callers are in > process context. > > - qla_nx.c: qla82xx_beacon_on(), bound to isp_operations ->beacon_on() > hook. That hook is only called once, in a mutex locked context, > from qla2x00_beacon_store(). > > - qla_nx.c: qla82xx_beacon_off(), bound to isp_operations > ->beacon_off() hook. Like ->beacon_on(), it's only called once, in > a mutex locked context, from qla2x00_beacon_store(). > > - qla_nx.c: qla82xx_fw_dump(), calls qla2x00_wait_for_chip_reset(), > which has msleep() in a loop. It is bound to isp_operations > ->fw_dump() hook. That hook *is* called from atomic context at > qla_isr.c by multiple interrupt handlers. Nonetheless, it's other > controllers interrupt handlers, and not the qla82xx. qla82xx_msix_default() and qla82xx_msix_rsp_q() call qla24xx_process_response_queue() which doesn't implement the firmware dumping. > - qla_attr.c: qla2x00_sysfs_write_fw_dump(), and > qla2x00_sysfs_write_reset(), process-context sysfs ->write() hooks. > > - qla_os.c: qla2x00_probe_one(). PCI ->probe(), process context. > > - qla_os.c: qla2x00_clear_drv_active(), called solely from > qla2x00_remove_one(), which is PCI ->remove() hook, process context. > > - qla_os.c: qla2x00_do_dpc(), kthread function, process context. > > Remove the in_interrupt() check. Change qla82xx_idc_lock() specification > to a purely process-context function. Mark it with "Context: task, might > sleep". > > Change qla82xx_idc_lock() implementation to sleep 100ms, instead of a > schedule(), for each spin. This is more deterministic, and it matches > the other qla models idc_lock() functions. > > 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> Reviewed-by: Daniel Wagner <dwagner@suse.de>
> On Nov 26, 2020, at 7:29 AM, Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote: > > From: "Ahmed S. Darwish" <a.darwish@linutronix.de> > > qla82xx_idc_lock() spins on a certain hardware state until it's updated. At > the end of each spin, if in_interrupt() is true, it does 20 loops of > cpu_relax(). Otherwise, it yields the CPU. > > While in_interrupt() is ill-defined and does not provide what the name > suggests, it is not needed here: qla82xx_idc_lock() is always called > from process context. Below is an analysis of its callers, in order of > appearance: > > - qla_nx.c: qla82xx_device_bootstrap(), only called by > qla82xx_device_state_handler(), has multiple msleep()s. > > - qla_nx.c: qla82xx_need_qsnt_handler(), has one second msleep() > > - qla_nx.c: qla82xx_wait_for_state_change(), one second msleep() > > - qla_nx.c: qla82xx_need_reset_handler(), can sleep up to 10 seconds > > - qla_nx.c: qla82xx_device_state_handler(), has multiple msleep()s > > - qla_nx.c: qla82xx_abort_isp(), if it's a qla82xx controller, calls > qla82xx_device_state_handler(), which sleeps. It's also bound to > isp_operations ->abort_isp() hook, where all the callers are in > process context. > > - qla_nx.c: qla82xx_beacon_on(), bound to isp_operations ->beacon_on() > hook. That hook is only called once, in a mutex locked context, > from qla2x00_beacon_store(). > > - qla_nx.c: qla82xx_beacon_off(), bound to isp_operations > ->beacon_off() hook. Like ->beacon_on(), it's only called once, in > a mutex locked context, from qla2x00_beacon_store(). > > - qla_nx.c: qla82xx_fw_dump(), calls qla2x00_wait_for_chip_reset(), > which has msleep() in a loop. It is bound to isp_operations > ->fw_dump() hook. That hook *is* called from atomic context at > qla_isr.c by multiple interrupt handlers. Nonetheless, it's other > controllers interrupt handlers, and not the qla82xx. > > - qla_attr.c: qla2x00_sysfs_write_fw_dump(), and > qla2x00_sysfs_write_reset(), process-context sysfs ->write() hooks. > > - qla_os.c: qla2x00_probe_one(). PCI ->probe(), process context. > > - qla_os.c: qla2x00_clear_drv_active(), called solely from > qla2x00_remove_one(), which is PCI ->remove() hook, process context. > > - qla_os.c: qla2x00_do_dpc(), kthread function, process context. > > Remove the in_interrupt() check. Change qla82xx_idc_lock() specification > to a purely process-context function. Mark it with "Context: task, might > sleep". > > Change qla82xx_idc_lock() implementation to sleep 100ms, instead of a > schedule(), for each spin. This is more deterministic, and it matches > the other qla models idc_lock() functions. > > 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_def.h | 5 +++++ > drivers/scsi/qla2xxx/qla_nx.c | 25 +++++++++++-------------- > 2 files changed, 16 insertions(+), 14 deletions(-) > > diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h > index ed9b10f8537d6..fe3c0e2f1ce88 100644 > --- a/drivers/scsi/qla2xxx/qla_def.h > +++ b/drivers/scsi/qla2xxx/qla_def.h > @@ -3296,8 +3296,10 @@ struct isp_operations { > void (*fw_dump)(struct scsi_qla_host *vha); > void (*mpi_fw_dump)(struct scsi_qla_host *, int); > > + /* Context: task, might sleep */ > int (*beacon_on) (struct scsi_qla_host *); > int (*beacon_off) (struct scsi_qla_host *); > + > void (*beacon_blink) (struct scsi_qla_host *); > > void *(*read_optrom)(struct scsi_qla_host *, void *, > @@ -3308,7 +3310,10 @@ struct isp_operations { > int (*get_flash_version) (struct scsi_qla_host *, void *); > int (*start_scsi) (srb_t *); > int (*start_scsi_mq) (srb_t *); > + > + /* Context: task, might sleep */ > int (*abort_isp) (struct scsi_qla_host *); > + > int (*iospace_config)(struct qla_hw_data *); > int (*initialize_adapter)(struct scsi_qla_host *); > }; > diff --git a/drivers/scsi/qla2xxx/qla_nx.c b/drivers/scsi/qla2xxx/qla_nx.c > index b3ba0de5d4fb8..b2017f1c35044 100644 > --- a/drivers/scsi/qla2xxx/qla_nx.c > +++ b/drivers/scsi/qla2xxx/qla_nx.c > @@ -489,29 +489,26 @@ qla82xx_rd_32(struct qla_hw_data *ha, ulong off_in) > return data; > } > > -#define IDC_LOCK_TIMEOUT 100000000 > +/* > + * Context: task, might sleep > + */ > int qla82xx_idc_lock(struct qla_hw_data *ha) > { > - int i; > - int done = 0, timeout = 0; > + const int delay_ms = 100, timeout_ms = 2000; > + int done, total = 0; > > - while (!done) { > + might_sleep(); > + > + while (true) { > /* acquire semaphore5 from PCI HW block */ > done = qla82xx_rd_32(ha, QLA82XX_PCIE_REG(PCIE_SEM5_LOCK)); > if (done == 1) > break; > - if (timeout >= IDC_LOCK_TIMEOUT) > + if (WARN_ON_ONCE(total >= timeout_ms)) > return -1; > > - timeout++; > - > - /* Yield CPU */ > - if (!in_interrupt()) > - schedule(); > - else { > - for (i = 0; i < 20; i++) > - cpu_relax(); > - } > + total += delay_ms; > + msleep(delay_ms); > } > > return 0; > -- > 2.29.2 > Looks Good. Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> -- Himanshu Madhani Oracle Linux Engineering
diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h index ed9b10f8537d6..fe3c0e2f1ce88 100644 --- a/drivers/scsi/qla2xxx/qla_def.h +++ b/drivers/scsi/qla2xxx/qla_def.h @@ -3296,8 +3296,10 @@ struct isp_operations { void (*fw_dump)(struct scsi_qla_host *vha); void (*mpi_fw_dump)(struct scsi_qla_host *, int); + /* Context: task, might sleep */ int (*beacon_on) (struct scsi_qla_host *); int (*beacon_off) (struct scsi_qla_host *); + void (*beacon_blink) (struct scsi_qla_host *); void *(*read_optrom)(struct scsi_qla_host *, void *, @@ -3308,7 +3310,10 @@ struct isp_operations { int (*get_flash_version) (struct scsi_qla_host *, void *); int (*start_scsi) (srb_t *); int (*start_scsi_mq) (srb_t *); + + /* Context: task, might sleep */ int (*abort_isp) (struct scsi_qla_host *); + int (*iospace_config)(struct qla_hw_data *); int (*initialize_adapter)(struct scsi_qla_host *); }; diff --git a/drivers/scsi/qla2xxx/qla_nx.c b/drivers/scsi/qla2xxx/qla_nx.c index b3ba0de5d4fb8..b2017f1c35044 100644 --- a/drivers/scsi/qla2xxx/qla_nx.c +++ b/drivers/scsi/qla2xxx/qla_nx.c @@ -489,29 +489,26 @@ qla82xx_rd_32(struct qla_hw_data *ha, ulong off_in) return data; } -#define IDC_LOCK_TIMEOUT 100000000 +/* + * Context: task, might sleep + */ int qla82xx_idc_lock(struct qla_hw_data *ha) { - int i; - int done = 0, timeout = 0; + const int delay_ms = 100, timeout_ms = 2000; + int done, total = 0; - while (!done) { + might_sleep(); + + while (true) { /* acquire semaphore5 from PCI HW block */ done = qla82xx_rd_32(ha, QLA82XX_PCIE_REG(PCIE_SEM5_LOCK)); if (done == 1) break; - if (timeout >= IDC_LOCK_TIMEOUT) + if (WARN_ON_ONCE(total >= timeout_ms)) return -1; - timeout++; - - /* Yield CPU */ - if (!in_interrupt()) - schedule(); - else { - for (i = 0; i < 20; i++) - cpu_relax(); - } + total += delay_ms; + msleep(delay_ms); } return 0;