scsi: isci: remote_node_context: Demote kernel-doc abuse

Fixes the following W=1 kernel build warning(s):

drivers/scsi/isci/remote_node_context.c:206: warning: Function parameter or member 'rnc' not described in 'sci_remote_node_context_notify_user'
drivers/scsi/isci/remote_node_context.c:206: warning: expecting prototype for This method just calls the user callback function and then resets the(). Prototype was for sci_remote_node_context_notify_user() instead

Link: https://lore.kernel.org/r/20210317091230.2912389-30-lee.jones@linaro.org
Cc: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: isci: remote_node_context: Fix one function header and demote a couple more

Fixes the following W=1 kernel build warning(s):

drivers/scsi/isci/remote_node_context.c:77: warning: Cannot understand *
drivers/scsi/isci/remote_node_context.c:167: warning: Cannot understand *
drivers/scsi/isci/remote_node_context.c:206: warning: Cannot understand *

Link: https://lore.kernel.org/r/20210317091230.2912389-25-lee.jones@linaro.org
Cc: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

scsi: isci: remote_node_context: mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases where
we are expecting to fall through.

Notice that, in this particular case, a dash is added as a token in order
to separate the "Fall through" annotations from the rest of the comment on
the same line, which is what GCC is expecting to find.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Artur Paszkiewicz <artur.paszkiewicz@intel.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: isci: avoid array subscript warning

I'm getting a new warning with gcc-7:

isci/remote_node_context.c: In function 'sci_remote_node_context_destruct':
isci/remote_node_context.c:69:16: error: array subscript is above array bounds [-Werror=array-bounds]

This is odd, since we clearly cover all values for enum
scis_sds_remote_node_context_states here. Anyway, checking for an array
overflow can't harm and it makes the warning go away.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

scsi: isci: fix spelling mistakes in dev_warn messages

Trivial fix to spelling mistake "suspeneded" to "suspended" in dev_warn
messages.

[mkp: corrected description. Patch is against the isci driver, not iscsi]

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

isci: End the RNC resumption wait when the RNC is destroyed.

While the RNC is suspended for I/O cleanup, the remote device can be
stopped and the RNC setup for destruction. These changes accomodate that
case in the abort path.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: Fixed RNC bug that lost the suspension or resumption during destroy

This fix corrects the saving of resume parameters when the destruction
of the RNC has already been directed, and makes sure not to overwrite
the RNC destruction callbacks.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: Fix RNC AWAIT_SUSPENSION->INVALIDATING transition.

The RNC state machine would incorrectly transition from
SCI_RNC_AWAIT_SUSPENSION directly to SCI_RNC_INVALIDATING when a destruct
request was made. This would skip the increment of the suspension count
and the abort of pending TCs (although the invalidating state would at
least cleanup outstanding TCs).

Instead, the RNC will transition to SCI_RNC_SUSPENDED and then start the
destruction process.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: Don't wait for an RNC suspend if it's being destroyed.

Make sure that the wait for suspend can handle the RNC destruction case.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: Added timeouts to RNC suspensions in the abort path.

This change adds timeouts to the RNC suspension wait. It makes the
suspend and resume timeouts the same.

The previous resume timeout of 5 ms was too short, and timeouts were
seen in resumptions of devices in the abort task/LUN reset path - which
would receive an RNC resumed message within a tenth of a second later.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: Fix RNC suspend call for SCI_RESUMING state.

Instead of immediately transitioning to the SCI_RNC_AWAIT_SUSPENSION
state, handle the SCI_RNC_RESUMING suspend transition from the
SCI_RNC_READY state like the SCI_RNC_INVALIDATING --> SCI_RNC_POSTING
transitions do now, by setting the destination state for the entry
into the READY state.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: When in the abort path, defeat other resume calls until done.

Completion of I/Os during the one of the abort path interface calls
from libsas can drive remote device state changes and the resumption
of the device RNC. This is a problem when the abort path is
attempting to cleanup outstanding I/O at the same time - the resumption
can prevent the termination from occuring correctly.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: Implement waiting for suspend in the abort path.

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>

isci: Manage the LLHANG timer enable/disable per-device.

The LLHANG timer should be enabled once per device. This patch corrects
both the timer enable and the timer disable for the remote device.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: Save the suspension hint for upcoming suspensions.

In the case of a suspend call while in SCI_RNC_POSTING or INVALIDATING
states, the LLHANG detect needed to be saved so the upcoming suspension
would enable it correctly. The unused suspend callback parameters were
removed.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: Distinguish between remote device suspension cases

For NCQ error conditions among others, there is no need to enable
the link layer hang detect timer.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: All pending TCs are terminated when the RNC is invalidated.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: Add suspension cases for RNC INVALIDATING, POSTING states.

The RNC can be any of the states in the loop from suspended to
ready when the API "suspend" or "resume" are called. This change
adds destination states parameters that control the suspension /
resumption action of the RNC statemachine for those transition states.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: Redesign device suspension, abort, cleanup.

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>

isci: Terminate outstanding TCs on TX/RX RNC suspensions.

TCs must only be terminated when RNCs are suspended.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: Handle all suspending TC completions

Add comprehensive decode for all TC completions that generate RNC
suspensions.

Note that this commit also removes unconditional resumptions of ATAPI
devices when in the SCI_STP_DEV_ATAPI_ERROR state, and STP devices
when in the SCI_STP_DEV_IDLE state. This is because the SCI_STP_DEV_IDLE
and SCI_STP_DEV_ATAPI state entry functions manage the RNC resumption.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: Fixed bug in resumption from RNC Tx/Rx suspend state.

The resumption from the Tx/Rx suspended state should work the same
as the Tx suspended state.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: Manage the link layer hang detect timer for RNC suspensions.

For STP devices under certain protocol conditions, an RNC will not
suspend until the current transfer state is broken with a SYNC/ESC
sequence from the SCU. The SYNC/ESC driven by expiration of the
SCU link layer hang detect timer, which has too small a dynamic
range to support slow SATA devices, so normally it is disabled.

This change enables the timer with the minimum period at the point
when the suspension is requested.

Note that there is potential collateral damage to other open
connections to slow SATA devices on the same port, since there
is no alternative but to enable the LLHANG timer on every phy in
the port for the current suspension request - there is no way to
tell on which phy the RNC in question is currently active.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: kill ->is_direct_attached

domain_device ->parent conveys the same information.

Occurrences of ->is_direct_attached appear next to incomplete open-coded
versions of dev_is_sata(), clean those up as well.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: improve 'invalid state' warnings

Convert controller state machine warnings to emit the state number (it
missed the number to string conversion, but since these error rarely
happen not much motivation to go further).

Fix up the rnc warnings to use the state name.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

[SCSI] isci: debug, provide state-enum-to-string conversions

Debugging the driver requires tracing the state transtions and tracing
state names is less work than decoding numbers.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

isci: kill 'get/set' macros

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>

isci: retire scic_sds_ and scic_ prefixes

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>

isci: unify isci_host and scic_sds_controller

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>

isci: unify isci_remote_device and scic_sds_remote_device

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>

isci: unify isci_request and scic_sds_request

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>

isci: Explicitly decode remote node ready and suspended states

The remote node context should only signal a device reset condition
in a suspended state.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: additional state machine cleanup

Additional state machine cleanups:

o Remove static functions sci_state_machine_exit_state() and
sci_state_machine_enter_state()
o Combines sci_base_state_machine_construct() and
sci_base_state_machine_start() into a single function,
sci_init_sm()
o Remove sci_base_state_machine_stop() which is unused.
o Kill state_machine.[ch]

Signed-off-by: Edmund Nadolski <edmund.nadolski@intel.com>
[fixed too large to inline functions]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: state machine cleanup

This cleans up several areas of the state machine mechanism:

o Rename sci_base_state_machine_change_state to sci_change_state
o Remove sci_base_state_machine_get_state function
o Rename 'state_machine' struct member to 'sm' in client structs
o Shorten the name of request states
o Shorten state machine state names as follows:
SCI_BASE_CONTROLLER_STATE_xxx to SCIC_xxx
SCI_BASE_PHY_STATE_xxx to SCI_PHY_xxx
SCIC_SDS_PHY_STARTING_SUBSTATE_xxx to SCI_PHY_SUB_xxx
SCI_BASE_PORT_STATE_xxx to SCI_PORT_xxx and
SCIC_SDS_PORT_READY_SUBSTATE_xxx to SCI_PORT_SUB_xxx
SCI_BASE_REMOTE_DEVICE_STATE_xxx to SCI_DEV_xxx
SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_xxx to SCI_STP_DEV_xxx
SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_xxx to SCI_SMP_DEV_xxx
SCIC_SDS_REMOTE_NODE_CONTEXT_xxx_STATE to SCI_RNC_xxx

Signed-off-by: Edmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: add some type safety to the state machine interface

Now that any given object type only has one state_machine we can use
container_of() to get back to the given state machine owner.

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: unify rnc start{io|task} handlers

Unify rnc start{io|task} handlers and delete the state handler
infrastructure.

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: unify rnc suspend/resume handlers

Unify rnc suspend/resume handlers and delete the state handlers.

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: unify rnc destruct handlers

Unify rnc destruct handlers and delete the state handler.

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: unify rnc event handlers

Unify rnc event handlers and delete the state handler.

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: uplevel port infrastructure

* Move port configuration agent implementation
* Merge core/scic_sds_port.[ch] into port.[ch]

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: uplevel request infrastructure

* Consolidate tiny header files
* Move files out of core/ (drop core/scic_sds_ prefix)
* Merge core/scic_sds_request.[ch] into request.[ch]
* Cleanup request.c namespace (clean forward declarations and global
namespace pollution)

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: uplevel state machine

unify core/sci_base_state.h and core/sci_base_state_machine.[ch] into
state_machine.[ch]

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: move core/controller to host

Now that the data structures are unified unify the implementation in
host.[ch] and cleanup namespace pollution.

Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: rnc state machine table c99 conversion

This makes the subsequent patches to delete rnc->state_handler more
clear.

Signed-off-by: Jacek Danecki <Jacek.Danecki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: Removed sci_base_object from scic_sds_remote_node_context.

The 'struct sci_base_object' was removed from the struct
scic_sds_remote_node_context.

Signed-off-by: Maciej Patelczyk <maciej.patelczyk@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: Removed struct sci_base_object from state machine.

Changed any occurrence of struct sci_base_object into void.

Signed-off-by: Maciej Patelczyk <maciej.patelczyk@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: remove scic_sds_remote_device_get_port_index

Longer to type than the open-coded equivalent.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: remove usage of sci_sas_address in scic_sds_remote_device

The sas address can be retrieved from the domain device and then
converted to the always little-endian format in the remote node context.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: kill smp_discover_response

An lldd need never look at the contents of an smp_discover_response frame.
Kill the remaining locations where isci is looking at it:

1/ covering for expanders that do not set the stp_attached bit (already
handled by sas_ex_discover_end_dev)
2/ an overkill method to notifiy the rest of the driver about remote_device
sas addresses

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: kill smp_discover_response_protocols in favor of domain_device.dev_type

This is step 1 of removing the contortions to:
1/ unparse expander phy data into a smp discover frame
2/ open-code-parse the smp discover fram into a domain_device.dev_type equivalent

libsas has already spent cycles determining the dev_type, so now that
scic_sds_remote_device is unified with isci_remote_device we can
directly reference dev_type.

This might also change multi-level expander detection as we previously only
looked at dev_type == EDGE_DEV and we did not consider the FANOUT_DEV case.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

isci: move remote_device handling out of the core

Now that the core/lldd remote_device data structures are nominally unified
merge the corresponding sources into the top-level directory. Also move the
remote_node_context infrastructure which has no analog at the lldd level.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>