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path: root/drivers/scsi/isci/task.c
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2014-12-12Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree update from Jiri Kosina: "Usual stuff: documentation updates, printk() fixes, etc" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (24 commits) intel_ips: fix a type in error message cpufreq: cpufreq-dt: Move newline to end of error message ps3rom: fix error return code treewide: fix typo in printk and Kconfig ARM: dts: bcm63138: change "interupts" to "interrupts" Replace mentions of "list_struct" to "list_head" kernel: trace: fix printk message scsi: mpt2sas: fix ioctl in comment zbud, zswap: change module author email clocksource: Fix 'clcoksource' typo in comment arm: fix wording of "Crotex" in CONFIG_ARCH_EXYNOS3 help gpio: msm-v1: make boolean argument more obvious usb: Fix typo in usb-serial-simple.c PCI: Fix comment typo 'COMFIG_PM_OPS' powerpc: Fix comment typo 'CONIFG_8xx' powerpc: Fix comment typos 'CONFiG_ALTIVEC' clk: st: Spelling s/stucture/structure/ isci: Spelling s/stucture/structure/ usb: gadget: zero: Spelling s/infrastucture/infrastructure/ treewide: Fix company name in module descriptions ...
2014-11-27libsas: remove task_collector modeChristoph Hellwig1-77/+70
The task_collector mode (or "latency_injector", (C) Dan Willians) is an optional I/O path in libsas that queues up scsi commands instead of directly sending it to the hardware. It generall increases latencies to in the optiomal case slightly reduce mmio traffic to the hardware. Only the obsolete aic94xx driver and the mvsas driver allowed to use it without recompiling the kernel, and most drivers didn't support it at all. Remove the giant blob of code to allow better optimizations for scsi-mq in the future. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Dan Williams <dan.j.williams@intel.com>
2014-10-29isci: Spelling s/stucture/structure/Geert Uytterhoeven1-1/+1
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: James E.J. Bottomley <JBottomley@parallels.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2014-03-10[SCSI] isci: fix reset timeout handlingDan Williams1-1/+1
Remove an erroneous BUG_ON() in the case of a hard reset timeout. The reset timeout handler puts the port into the "awaiting link-up" state. The timeout causes the device to be disconnected and we need to be in the awaiting link-up state to re-connect the port. The BUG_ON() made the incorrect assumption that resets never timeout and we always complete the reset in the "resetting" state. Testing this patch also uncovered that libata continues to attempt to reset the port long after the driver has torn down the context. Once the driver has committed to abandoning the link it must indicate to libata that recovery ends by returning -ENODEV from ->lldd_I_T_nexus_reset(). Cc: <stable@vger.kernel.org> Acked-by: Lukasz Dorau <lukasz.dorau@intel.com> Reported-by: David Milburn <dmilburn@redhat.com> Reported-by: Xun Ni <xun.ni@intel.com> Tested-by: Xun Ni <xun.ni@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-07-23[SCSI] isci: Fix a race condition in the SSP task management pathJeff Skirvin1-3/+6
This commit fixes a race condition in the isci driver abort task and SSP device task management path. The race is caused when an I/O termination in the SCU hardware is necessary because of an SSP target timeout condition, and the check of the I/O end state races against the HW-termination-driven end state. The failure of the race meant that no TMF was sent to the device to clean-up the pending I/O. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Reviewed-by: Lukasz Dorau <lukasz.dorau@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2013-05-10[SCSI] sas: unify the pointlessly separated enums sas_dev_type and ↵James Bottomley1-1/+1
sas_device_type These enums have been separate since the dawn of SAS, mainly because the latter is a procotol only enum and the former includes additional state for libsas. The dichotomy causes endless confusion about which one you should use where and leads to pointless warnings like this: drivers/scsi/mvsas/mv_sas.c: In function 'mvs_update_phyinfo': drivers/scsi/mvsas/mv_sas.c:1162:34: warning: comparison between 'enum sas_device_type' and 'enum sas_dev_type' [-Wenum-compare] Fix by eliminating one of them. The one kept is effectively the sas.h one, but call it sas_device_type and make sure the enums are all properly namespaced with the SAS_ prefix. Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-09-01treewide: fix comment/printk/variable typosAnatol Pomozov1-1/+1
Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-05-18isci: Check IDEV_GONE before performing abort path operations.Jeff Skirvin1-21/+34
In the link fail path, set IDEV_GONE for every device on the domain when the last link in the port fails. In the abort path functions like isci_reset_device, make sure that there has not already been a detected domain failure with the device by checking IDEV_GONE, before performing any kind of hard reset, SMP phy control, or TMF operation. The check for IDEV_GONE makes sure that the device in the abort path really has control of the port with which it is associated. This prevents starting hard resets at incorrect times and scheduling unnecessary LUN resets for SATA devices. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2012-05-18isci: Directly control IREQ_ABORT_PATH_ACTIVE when completing TMFs.Jeff Skirvin1-0/+3
TMF requests, unlike normal I/O requests, need to handle I/O management conditions in the completion function because TMFs are not handled in the completion tasklet. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2012-05-18isci: Manage tag releases differently when aborting tasks.Jeff Skirvin1-1/+2
When an individual request is being terminated, the request's tag is managed in the terminate function. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2012-05-18isci: Implement waiting for suspend in the abort path.Jeff Skirvin1-7/+7
In order to prevent a device from receiving an I/O request while still in an RNC suspending or resuming state (and therefore failing that I/O back to libsas with a reset required status) wait for the RNC state change before proceding in the abort path. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2012-05-18isci: Make sure all TCs are terminated and cleaned in LUN reset.Jeff Skirvin1-6/+8
In the libsas error path, SATA disks require extra handling in libata to recover operation. However, libsas expects to be able to immediately recover all outstanding I/O once the error handler escalation stops. This patch fixes the condition where the libata error handler is scheduled for operation but libsas has already deleted the outstanding sas_tasks. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2012-05-18isci: Remove isci_device reqs_in_process and dev_node from isci_device.Jeff Skirvin1-4/+0
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2012-05-18isci: Device access in the error path does not depend on IDEV_GONE.Jeff Skirvin1-2/+5
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2012-05-18isci: Redesign device suspension, abort, cleanup.Jeff Skirvin1-653/+105
This commit changes the means by which outstanding I/Os are handled for cleanup. The likelihood is that this commit will be broken into smaller pieces, however that will be a later revision. Among the changes: - All completion structures have been removed from the tmf and abort paths. - Now using one completed I/O list, with the I/O completed in host bit being used to select error or normal callback paths. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2012-05-18isci: Escalate to I_T_Nexus_Reset when the device is gone.Jeff Skirvin1-2/+2
If LUN reset sees that the device is gone, it returns TMF_RESP_FUNC_FAILED to cause libsas to escalate to an I_T_Nexus_Reset. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2012-05-18isci: Manage device suspensions during TC terminations.Jeff Skirvin1-32/+48
TCs must be terminated only while the RNC is suspended. This commit adds remote device suspensions and resumptions in the abort, reset and termination paths. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2012-03-01[SCSI] isci: remove IDEV_EH hack to disable "discovery-time" ata resetsDan Williams1-5/+4
Prior to commit 61aaff49 "isci: filter broadcast change notifications during SMP phy resets" we borrowed the MVS_DEV_EH approach from the mvsas driver for preventing ->lldd_I_T_nexus_reset() events during ata discovery. This hack was protecting against the old ->phy_reset() in ata_bus_probe(), but since the conversion to the new error handling this hack is preventing resets from reaching ata devices. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-03-01[SCSI] isci: remove bus and reset handlersDan Williams1-23/+0
Remove ->eh_device_reset_handler() and ->eh_bus_reset_handler() for the same reason they are not implemented for libata hosts, they cannot be implemented reliably with ata-eh. ATA error recovery wants to divert all resets to the eh thread and wait for completion, these handlers may be invoked from a non-blocking ioctl. The other path they are called from is libsas-eh, and if we escalate past I_T_nexus reset we have larger problems i.e. tear down all in-flight commands in the domain potentially without notification to the lldd if it has chosen not to implement ->lldd_clear_nexus_port() / ->lldd_clear_nexus_ha(). Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-03-01[SCSI] isci: stop interpreting ->lldd_lu_reset() as an ata soft-resetDan Williams1-86/+7
Driving resets from libsas-eh is pre-mature as libata will make a decision about performing a softreset. Currently libata determines whether to perform a softreset based on ata_eh_followup_srst_needed(), and none of those conditions apply to isci. Remove the srst implementation and translate ->lldd_lu_reset() for ata devices as a request to drive a reset via libata-eh. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-03-01[SCSI] isci: fix interpretation of "hard" resetDan Williams1-9/+15
A hard reset to isci in the direct-attached case is one where the driver internally manages debouncing the link. In the sas-expander-attached case a hard reset is one that clears affiliations. The driver should not be prematurely dropping affiliations at run time, that decision (to force expander hard resets to ata devices) is left to userspace to manage. So, arrange for I_T_nexus resets to be sas-link-resets in the expander-attached case and isci-hard-resets in the direct-attached case. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-02-29[SCSI] libsas: fix sas_find_local_phy(), take phy referencesDan Williams1-4/+5
In the direct-attached case this routine returns the phy on which this device was first discovered. Which is broken if we want to support wide-targets, as this phy reference can become stale even though the port is still active. In the expander-attached case this routine tries to lookup the phy by scanning the attached sas addresses of the parent expander, and BUG_ONs if it can't find it. However since eh and the libsas workqueue run independently we can still be attempting device recovery via eh after libsas has recorded the device as detached. This is even easier to hit now that eh is blocked while device domain rediscovery takes place, and that libata is fed more timed out commands increasing the chances that it will try to recover the ata device. Arrange for dev->phy to always point to a last known good phy, it may be stale after the port is torn down, but it will catch up for wide port reconfigurations, and never be NULL. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-02-19[SCSI] libsas: remove ata_port.lock management duties from llddsDan Williams1-4/+2
Each libsas driver (mvsas, pm8001, and isci) has invented a different method for managing the ap->lock. The lock is held by the ata ->queuecommand() path. mvsas drops it prior to acquiring any internal locks which allows it to hold its internal lock across calls to task->task_done(). This capability is important as it is the only way the driver can flush task->task_done() instances to guarantee that it no longer has any in-flight references to a domain_device at ->lldd_dev_gone() time. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2012-01-16[SCSI] isci: remove unused 'isci_tmf->device' fieldMaciej Trela1-1/+1
As the field was never set, isci_print_tmf() using 'isci_tmf->device' sometimes causes a kernel crash if the dev_dbg() statement is enabled. Remove the unused field both from isci_tmf struct definition and from isci_print_tmf() Signed-off-by: Maciej Trela <maciej.trela@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-10-31[SCSI] isci: revert bcn filteringDan Williams1-235/+0
The initial bcn filtering implementation was validated on a kernel baseline that predated the switch to new libata error handling. Also, prior to that conversion we borrowed the mvsas MVS_DEV_EH approach to prevent the unwanted extra ap->ops->phy_reset(ap) that occurred in the ata_bus_probe() path. After the conversion to new libata eh resets at discovery are more frequent and get filtered prematurely by IDEV_EH. The result is that our bcn filtering has been blocked from running and at discovery and it appears to stall discovery completion to the point of triggering hung task timeouts. So, revert the implementation for now. When it returns it will go into libsas proper. The domain rediscovery that takes place due to ->lldd_I_T_nexus_reset() events should now be properly waited for by the ata_port_wait_eh() call in ata_port_probe(). So the hard coded delay in the isci ->lldd_I_T_nexus_reset() and other libsas drivers should help debounce the libsas thread from seeing temporary device removals. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-10-31[SCSI] isci: No need to manage the pending reset bit on pending requests.Jeff Skirvin1-3/+0
The lldd does not need to look at or manage the pending device reset bit in pending sas_tasks. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-10-31[SCSI] isci: Remove redundant isci_request.ttype field.Jeff Skirvin1-14/+15
Use the existing IREQ_TMF flag as a request type indicator. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-10-31[SCSI] isci: Fix task management for SMP, SATA and on dev remove.Jeff Skirvin1-105/+64
libsas uses the LLDD abort task interface to handle I/O timeouts in the SATA/STP and SMP discovery paths, so this change will terminate STP/SMP requests. Also, if the device is gone, the lldd will prevent libsas from further escalations in the error handler. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-10-31[SCSI] isci: No task_done callbacks in error handler paths.Jeff Skirvin1-55/+14
libsas will cleanup pending sas_tasks after error handler path functions are called; do not call task_done callbacks. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-10-31[SCSI] isci: Handle task request timeouts correctly.Jeff Skirvin1-42/+107
In the case where "task" requests timeout (note that this class of requests can also include SATA/STP soft reset FIS transmissions), handle the case where the task was being managed by some call to terminate the task request by completing both the tmf and the aborting process. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-10-31[SCSI] isci: Fix tag leak in tasks and terminated requests.Jeff Skirvin1-20/+31
Make sure terminated requests and completed task tags are freed. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-10-31[SCSI] isci: Immediately fail I/O to removed devices.Jeff Skirvin1-10/+21
In the case where an I/O fails to start in isci_request_execute, only allow retries if the device is not already gone. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-08-27[SCSI] libsas: export sas_alloc_task()Dan Williams1-26/+3
Now that isci has added a 3rd open coded user of this functionality just share the libsas version. Acked-by: Jack Wang <jack_wang@usish.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-07-03[SCSI] isci: fix checkpatch errorsJames Bottomley1-35/+36
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
2011-07-03isci: Device reset should request sas_phy_reset(phy, true)Jeff Skirvin1-12/+6
The hard_reset parameter passed to the LLDD in the direct-attached phy control case allows the LLDD to filter link failure events while the direct-attached device reset is executing. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03isci: pare back error messsagesDan Williams1-19/+19
The messages emitted from task.c and some from request.c likely duplicate (in a less undertandable way) what is reported by the midlayer. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03isci: merge sata.[ch] into request.cDan Williams1-20/+80
Undo some needless separation. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03isci: kill 'get/set' macrosDan Williams1-1/+1
Most of these simple dereference macros are longer than their open coded equivalent. Deleting enum sci_controller_mode is thrown in for good measure. Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03isci: retire scic_sds_ and scic_ prefixesDan Williams1-12/+12
The distinction between scic_sds_ scic_ and sci_ are no longer relevant so just unify the prefixes on sci_. The distinction between isci_ and sci_ is historically significant, and useful for comparing the old 'core' to the current Linux driver. 'sci_' represents the former core as well as the routines that are closer to the hardware and protocol than their 'isci_' brethren. sci == sas controller interface. Also unwind the 'sds1' out of the parameter structs. Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03isci: unify isci_host and scic_sds_controllerDan Williams1-23/+21
Remove the distinction between these two implementations and unify on isci_host (local instances named ihost). Hmmm, we had two 'oem_parameters' instances, one was unused... nice. Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03isci: unify isci_remote_device and scic_sds_remote_deviceDan Williams1-26/+21
Remove the distinction between these two implementations and unify on isci_remote_device (local instances named idev). Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03isci: unify isci_request and scic_sds_requestDan Williams1-9/+8
They are one in the same object so remove the distinction. The near duplicate fields (owning_controller, and isci_host) will be cleaned up after the scic_sds_contoller isci_host unification. Reported-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03isci: preallocate requestsDan Williams1-13/+6
the dma_pool interface is optimized for object_size << page_size which is not the case with isci_request objects and the dma_pool routines show up in the top of the profile. The old io_request_table which tracked whether tci slots were in-flight or not is replaced with an IREQ_ACTIVE flag per request. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03isci: combine request flagsDan Williams1-12/+11
Combine three bools into one unsigned long 'flags'. Doesn't increase the request size due to packing. (to do: optimize the structure layout). Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03isci: unify can_queue tracking on the tci_pool, uplevel tag assignmentDan Williams1-37/+43
The tci_pool tracks our outstanding command slots which are also the 'index' portion of our tags. Grabbing the tag early in ->lldd_execute_task let's us drop the isci_host_can_queue() and ->was_tag_assigned_by_user infrastructure. ->was_tag_assigned_by_user required the task context to be duplicated in request-local buffer. With the tci established early we can build the task_context directly into its final location and skip a memcpy. With the task context buffer at a known address at request construction we have the opportunity/obligation to also fix sgl handling. This rework feels like it belongs in another patch but the sgl handling and task_context are too intertwined. 1/ fix the 'ab' pair embedded in the task context to point to the 'cd' pair in the task context (previously we were prematurely linking to the staging buffer). 2/ fix the broken iteration of pio sgls that assumes all sgls are relative to the request, and does a dangerous looking reverse lookup of physical address to virtual address. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03isci: Terminate dev requests on FIS err bit rx in NCQJeff Skirvin1-2/+14
When the remote device transitions to a not-ready state because of an NCQ error condition, all outstanding requests to that device are terminated and completed to libsas on the normal path. The device then waits for a READ LOG EXT command to issue on the task management path. Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03isci: fix isci_task_execute_tmf completionDan Williams1-12/+8
1/ fix the timeout for wait_for_completion_timeout 2/ In the tmf timeout case we need to wait for our termination callback 3/ Once the request is successfully started it will be freed according to the normal lifetime for requests. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03isci: kill isci_remote_device_change_state()Dan Williams1-46/+22
Now that "stopping/stopped" are one in the same and signalled by a NULL device pointer the rest of the device status infrastructure can be removed (->status and ->state_lock). The "not ready for i/o state" is replaced with a state flag, and is evaluated under scic_lock so that we don't see transients from taking the device reference to submitting the i/o. This also fixes a potential leakage of can_queue slots in the rare case that SAS_TASK_ABORTED is set at submission. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03isci: atomic device lookup and reference countingDan Williams1-140/+91
We have unsafe references to remote devices that are notified to disappear at lldd_dev_gone. In order to clean this up we need a single canonical source for device lookups and stable references once a lookup succeeds. Towards that end guarantee that domain_device.lldd_dev is NULL as soon as we start the process of stopping a device. Any code path that wants to safely lookup a remote device must do so through task->dev->lldd_dev (isci_lookup_device()). For in-flight references outside of scic_lock we need reference counting to ensure that the device is not recycled before we are done with it. Simplify device back references to just scic_sds_request.target_device which is now the only permissible internal reference that is maintained relative to the reference count. There were two occasions where we wanted new i/o's to be treated as SAS_TASK_UNDELIVERED but where the domain_dev->lldd_dev link is still intact. Introduce a 'gone' flag to prevent i/o while waiting for libsas to take action on the port down event. One 'core' leftover is that we currently call scic_remote_device_destruct() from isci_remote_device_deconstruct() which is called when the 'core' says the device is stopped. It would be more natural for the final put to trigger isci_remote_device_deconstruct() but this implementation is deferred as it requires other changes. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-07-03isci: cleanup request allocationDan Williams1-86/+50
Rather than return an error code and update a pointer that was passed by reference just return the request object directly (or null if allocation failed). Signed-off-by: Dan Williams <dan.j.williams@intel.com>