mirror of
https://github.com/SCST-project/scst.git
synced 2026-05-17 10:41:26 +00:00
bb82ef36cc
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.
Link: https://lore.kernel.org/r/20201126132952.2287996-5-bigeasy@linutronix.de
Cc: Nilesh Javali <njavali@marvell.com>
Cc: <GR-QLogic-Storage-Upstream@marvell.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
See also upstream commit 8ac246bdd07a0f948f0e33eb4797bd2645cd8224.
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@9288 d57e44dd-8a1f-0410-8b47-8ef2f437770f
Overview
This is the source code repository of the SCST project. SCST is a collection of Linux kernel drivers that implement SCSI target functionality. The SCST project includes:
- The SCST core in the scst/ subdirectory.
- A tool for loading, saving and modifying the SCST configuration in directory scstadmin/.
- Several SCSI target drivers in the directories iscsi-scst/, qla2x00t/, srpt/, scst_local/ and fcst/.
- User space programs in the usr/ subdirectory, e.g. fileio_tgt.
- Various documentation in the doc/ subdirectory.
Instructions for building and installing SCST are available in the INSTALL.md file.
QLogic target driver
Two QLogic target drivers are included in the SCST project. The driver in the qla2x00t directory is a very stable driver that supports up to 16 Gb/s adapters. It is very stable, well tested and actively used in many production setups.
There is also a newer driver that supports 32 Gb/s FC in the qla2x00t-32gbit directory. That driver has not yet reached the same maturity level as the old qla2x00t driver.
Vladislav Bolkhovitin vst@vlnb.net, http://scst.sourceforge.net