linux-dev/drivers/scsi/libsas/sas_init.c, branch linus/master

scsi: libsas: Defer works of new phys during suspend

2021-12-23T04:38:30Z

During the processing of event PORT_BYTES_DMAED, the driver queues work DISCE_DISCOVER_DOMAIN and then flushes workqueue ha->disco_q. If a new phyup event occurs during resuming the controller, the work PORTE_BYTES_DMAED of new phy occurs before suspended phy's. The work DISCE_DISCOVER_DOMAIN of new phy requires an active SAS controller (it needs to resume SAS controller by function scsi_sysfs_add_sdev() and some other functions such as function add_device_link()). However, the activation of the SAS controller requires completion of work PORTE_BYTES_DMAED of suspended phys while it is blocked by new phy's work on ha->event_q. So there is a deadlock and it is released only after resume timeout. To solve the issue, defer works of new phys during suspend and queue those defer works after SAS controller becomes active. Link: https://lore.kernel.org/r/1639999298-244569-13-git-send-email-chenxiang66@hisilicon.com Reviewed-by: John Garry Signed-off-by: Xiang Chen Signed-off-by: Martin K. Petersen

scsi: libsas: Add flag SAS_HA_RESUMING

2021-12-23T04:38:30Z

Add a flag SAS_HA_RESUMING and use it to indicate the state of resuming the host controller. Link: https://lore.kernel.org/r/1639999298-244569-11-git-send-email-chenxiang66@hisilicon.com Reviewed-by: John Garry Signed-off-by: Xiang Chen Signed-off-by: Martin K. Petersen

scsi: libsas: Insert PORTE_BROADCAST_RCVD event for resuming host

2021-12-23T04:38:30Z

If a new disk is inserted through an expander when the host was suspended, it will not necessarily be detected as the topology is not re-scanned during resume. To detect possible changes in topology during suspension, insert a PORTE_BROADCAST_RCVD event per port when resuming to trigger a revalidation. Link: https://lore.kernel.org/r/1639999298-244569-8-git-send-email-chenxiang66@hisilicon.com Reviewed-by: John Garry Signed-off-by: Xiang Chen Signed-off-by: Martin K. Petersen

scsi: libsas: Don't always drain event workqueue for HA resume

2021-12-23T04:38:29Z

For the hisi_sas driver, if a directly attached disk is removed during suspend, a hang will occur in the resume process: The background is that in commit 16fd4a7c5917 ("scsi: hisi_sas: Add device link between SCSI devices and hisi_hba"), it is ensured that the HBA device cannot be runtime suspended when any SCSI device associated is active. Other drivers which use libsas don't worry about this as none support runtime suspend. The mentioned hang occurs when an disk is removed during suspend. In the removal process - from PHYE_RESUME_TIMEOUT event processing - we call into scsi_remove_device(), which is being processed in the HA event workqueue. Here we wait for all suppliers of the SCSI device to resume, which includes the HBA device (from the above commit). However the HBA device cannot resume, as it is waiting for the PHYE_RESUME_TIMEOUT to be processed (from calling sas_resume_ha() -> sas_drain_work()). This is the deadlock. There does not appear to be any need for the sas_drain_work() to be called at all in sas_resume_ha() as it is not syncing against anything, so allow LLDDs to avoid this by providing a variant of sas_resume_ha() which does "sync", i.e. doesn't drain the event workqueue. Link: https://lore.kernel.org/r/1639999298-244569-2-git-send-email-chenxiang66@hisilicon.com Signed-off-by: John Garry Signed-off-by: Xiang Chen Signed-off-by: Martin K. Petersen

scsi: libsas: Export sas_phy_enable()

2021-10-13T02:46:06Z

Export sas_phy_enable() so LLDDs can directly use it to control remote phys. We already do this for companion function sas_phy_reset(). Link: https://lore.kernel.org/r/1634041588-74824-4-git-send-email-john.garry@huawei.com Signed-off-by: Luo Jiaxing Signed-off-by: John Garry Signed-off-by: Martin K. Petersen

scsi: libsas: Co-locate exports with symbols

2021-09-14T03:57:39Z

It is standard practice to co-locate export declarations with the symbol which is being exported. Or at least in the same file - see sas_phy_reset(). Modify libsas to follow this practice consistently. Link: https://lore.kernel.org/r/1631530296-32358-1-git-send-email-john.garry@huawei.com Reviewed-by: Jason Yan Signed-off-by: John Garry Signed-off-by: Martin K. Petersen

scsi: libsas: Allow libsas to include SCSI header files directly

2021-07-21T03:11:17Z

libsas needs to include some header files in the scsi directory. However these are currently hardcoded with the path "../" in the C files. Do this in the Makefile to avoid hardcoding the path. Link: https://lore.kernel.org/r/20210716074551.771312-1-yanaijie@huawei.com Cc: John Garry Reviewed-by: John Garry Signed-off-by: Jason Yan Signed-off-by: Martin K. Petersen

scsi: libsas: Remove temporarily-added _gfp() API variants

2021-01-23T02:31:10Z

These variants were added for bisectability. Remove them, as all call sites have now been convertd to use the original API. Link: https://lore.kernel.org/r/20210118100955.1761652-20-a.darwish@linutronix.de Cc: Jason Yan Reviewed-by: John Garry Signed-off-by: Ahmed S. Darwish Signed-off-by: Martin K. Petersen

scsi: libsas: Switch back to original event notifiers API

2021-01-23T02:31:09Z

libsas event notifiers required an extension where gfp_t flags must be explicitly passed. For bisectability, a temporary _gfp() variant of such functions were added. All call sites then got converted use the _gfp() variants and explicitly pass GFP context. Having no callers left, the original libsas notifiers were then modified to accept gfp_t flags by default. Switch back to the original event notifiers API, while still passing GFP context. The _gfp() notifier variants will be removed afterwards. Link: https://lore.kernel.org/r/20210118100955.1761652-17-a.darwish@linutronix.de Cc: Jason Yan Reviewed-by: John Garry Signed-off-by: Ahmed S. Darwish Signed-off-by: Martin K. Petersen

scsi: libsas: Add gfp_t flags parameter to event notifications

2021-01-23T02:31:09Z

All call-sites of below libsas APIs: - sas_alloc_event() - sas_notify_port_event() - sas_notify_phy_event() have been converted to use the _gfp()-suffixed version. Modify the original APIs above to take a gfp_t flags parameter by default. For bisectability, call-sites will be modified again to use the original libsas APIs (while passing gfp_t). The temporary _gfp()-suffixed versions can then be removed. Link: https://lore.kernel.org/r/20210118100955.1761652-13-a.darwish@linutronix.de Cc: Jason Yan Reviewed-by: John Garry Signed-off-by: Ahmed S. Darwish Signed-off-by: Martin K. Petersen