With the current value of cmd_per_lun at 16, the throughput
over a single adapter is limited to around 150kIOPS.

Increase the value of cmd_per_lun to 256 to improve
throughput. With this change a single adapter is able to
attain close to the maximum throughput (380kIOPS).
Also change the number of RRQ entries that can be queued.
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: NUma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

When switching to the internal LUN defined on the
IBM CXL flash adapter, there is an unnecessary
scan occurring on the second port. This scan leads
to the following extra lines in the log:

Dec 17 10:09:00 tul83p1 kernel: [ 3708.561134] cxlflash 0008:00:00.0: cxlflash_queuecommand: (scp=c0000000fc1f0f00) 11/1/0/0 cdb=(A0000000-00000000-10000000-00000000)
Dec 17 10:09:00 tul83p1 kernel: [ 3708.561147] process_cmd_err: cmd failed afu_rc=32 scsi_rc=0 fc_rc=0 afu_extra=0xE, scsi_extra=0x0, fc_extra=0x0

By definition, both of the internal LUNs are on the first port/channel.

When the lun_mode is switched to internal LUN the
same value for host->max_channel is retained. This
causes an unnecessary scan over the second port/channel.

This fix alters the host->max_channel to 0 (1 port), if internal
LUNs are configured and switches it back to 1 (2 ports) while
going back to external LUNs.
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: NUma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

When operating in the PowerVM environment, the cxlflash module can
receive an error from the hypervisor indicating that there are
existing mappings in the page table for the process MMIO space.

This issue exists because term_afu() currently invokes term_mc()
before stop_afu(), allowing for the master context to be detached
first and the problem state area to be unmapped second.

To resolve this issue, stop_afu() should be called before term_mc().
Signed-off-by: NUma Krishnan <ukrishn@linux.vnet.ibm.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The calls to pci_request_regions(), pci_resource_start(),
pci_set_dma_mask(), pci_set_master() and pci_save_state() are all
unnecessary for the IBM CXL flash adapter since data buffers
are not required to be mapped to the device's memory.

The use of services such as pci_set_dma_mask() are problematic on
hypervisor managed systems as the IBM CXL flash adapter is operating
under a virtual PCI Host Bridge (virtual PHB) which does not support
these services.

cxlflash 0001:00:00.0: init_pci: Failed to set PCI DMA mask rc=-5

The resolution is to simplify init_pci(), to a point where it does the
bare minimum (pci_enable_device). Similarly, remove the call the
pci_release_regions() from cxlflash_remove().
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: NUma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

This drop enables a future card with a device id of 0x0600 to be
recognized by the cxlflash driver.

As per the design, the Accelerator Function Unit (AFU) for this new IBM
CXL Flash Adapter retains the same host interface as the previous
generation. For the early prototypes of the new card, the driver with
this change behaves exactly as the driver prior to this behaved with the
earlier generation card. Therefore, no card specific programming has
been added. These card specific changes can be staged in later if
needed.
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

If an async error interrupt is generated, and the error requires the FC
link to be reset, it cannot be performed in the interrupt context. So a
work element is scheduled to complete the link reset in a process
context. If either an EEH event or an escalation occurs in between when
the interrupt is generated and the scheduled work is started, the MMIO
space may no longer be available. This will cause an oops in the worker
thread.

[  606.806583] NIP kthread_data+0x28/0x40
[  606.806633] LR wq_worker_sleeping+0x30/0x100
[  606.806694] Call Trace:
[  606.806721] 0x50 (unreliable)
[  606.806796] wq_worker_sleeping+0x30/0x100
[  606.806884] __schedule+0x69c/0x8a0
[  606.806959] schedule+0x44/0xc0
[  606.807034] do_exit+0x770/0xb90
[  606.807109] die+0x300/0x460
[  606.807185] bad_page_fault+0xd8/0x150
[  606.807259] handle_page_fault+0x2c/0x30
[  606.807338] wait_port_offline.constprop.12+0x60/0x130 [cxlflash]

To prevent the problem space area from being unmapped, when there is
pending work, a mapcount (using the kref mechanism) is held.  The
mapcount is released only when the work is completed.  The last
reference release is tied to the unmapping service.
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: NUma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

After a few iterations of resetting the card, either during EEH
recovery, or a host_reset the following is seen in the logs.  cxlflash
0008:00: cxlflash_queuecommand: could not get a free command

At every reset of the card, the commands that are outstanding are being
leaked.  No effort is being made to reap these commands.  A few more
resets later, the above error message floods the logs and the card is
rendered totally unusable as no free commands are available.

Iterated through the 'cmd' queue and printed out the 'free' counter and
found that on each reset certain commands were in-use and stayed in-use
through subsequent resets.

To resolve this issue, when the card is reset, reap all the commands
that are active/outstanding.
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

Having a date for the driver requires it to be updated quite
often. Removing the date which is not necessary. Also made
use of the existing symbol to print the driver name.
Signed-off-by: NUma Krishnan <ukrishn@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

The original fix to escalate a 'login timed out' error to a LINK_RESET
was only made for one of the two ports on the card. This fix resolves
the same issue for the second port (port 1).
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: NUma Krishnan <ukrishn@linux.vnet.ibm.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

When running with lock instrumentation (e.g. lockdep), some of the
instrumentation can become disabled at probe time for a cxlflash
adapter. This is due to a missing lock registration for the tmf_slock.

The fix is to call spin_lock_init() for the tmf_slock during probe.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: NManoj Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

A 'login timed out' asynchronous error interrupt is generated if no
response is seen to a FLOGI within 2 seconds.  If the time out error
is not escalated to a LINK_RESET the port will not be available for
use. This fix provides the required escalation.
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

When running with an unsupported AFU, the cxlflash driver fails
the probe. When the driver is removed, the following Oops is
encountered on a show_interrupts() thread:

Call Trace:
[c000001fba5a7a10] [0000000000000003] 0x3 (unreliable)
[c000001fba5a7a60] [c00000000053dcf4] vsnprintf+0x204/0x4c0
[c000001fba5a7ae0] [c00000000030045c] seq_vprintf+0x5c/0xd0
[c000001fba5a7b20] [c00000000030051c] seq_printf+0x4c/0x60
[c000001fba5a7b50] [c00000000013e140] show_interrupts+0x370/0x4f0
[c000001fba5a7c10] [c0000000002ff898] seq_read+0xe8/0x530
[c000001fba5a7ca0] [c00000000035d5c0] proc_reg_read+0xb0/0x110
[c000001fba5a7cf0] [c0000000002ca74c] __vfs_read+0x6c/0x180
[c000001fba5a7d90] [c0000000002cb464] vfs_read+0xa4/0x1c0
[c000001fba5a7de0] [c0000000002cc51c] SyS_read+0x6c/0x110
[c000001fba5a7e30] [c000000000009204] system_call+0x38/0xb4

The Oops is due to not cleaning up correctly on the unsupported
AFU error path, leaving various allocated and registered resources.
In this case, interrupts are in a semi-allocated/registered state,
which the show_interrupts() thread attempts to use.

To fix, the cleanup logic in init_afu() is consolidated to error
gates at the bottom of the function and the appropriate goto is
added to each error path. As a mini side fix while refactoring
in this routine, the else statement following the AFU version
evaluation is eliminated as it is not needed.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Acked-by: NManoj Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

The trace following the failure of alloc_mem() incorrectly identifies
which function failed. This can lead to misdiagnosing a failure.

Fix the string to correctly indicate that alloc_mem() failed.
Reported-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

The fops owned by the adapter can be corrupted in certain scenarios,
opening a window where certain fops are temporarily NULLed before being
reset to their proper value. This can potentially lead software to make
incorrect decisions, leaving the user with the inability to function as
intended.

An example of this behavior can be observed when there are a number of
users with a high rate of turn around (attach to LUN, perform an I/O,
detach from LUN, repeat). Every so often a user is given a valid
context and adapter file descriptor, but the file associated with the
descriptor lacks the correct read permission bit (FMODE_CAN_READ) and
thus the read system call bails before calling the valid read fop.

Background:

The fops is stored in the adapter structure to provide the ability to
lookup the adapter structure from within the fop handler. CXL services
use the file's private_data and at present, the CXL context does not
have a private section. In an effort to limit areas of the cxlflash
driver with code specific the superpipe function, a design choice was
made to keep the details of the fops situated away from the legacy
portions of the driver. This drove the behavior that the adapter fops
is set at the beginning of the disk attach ioctl handler when there
are no users present.

The corruption that this fix remedies is due to the fact that the fops
is initially defaulted to values found within a static structure. When
the fops is handed down to the CXL services later in the attach path,
certain services are patched. The fops structure remains correct until
the user count drops to 0 and the fops is reset, triggering the process
to repeat again. The user counts are tightly coupled with the creation
and deletion of the user context. If multiple users perform a disk
attach at the same time, when the user count is currently 0, some users
can be in the middle of obtaining a file descriptor and have not yet
reached the context creation code that [in addition to creating the
context] increments the user count. Subsequent users coming in to
perform the attach see that the user count is still 0, and reinitialize
the fops, temporarily removing the patched fops. The users that are in
the middle obtaining their file descriptor may then receive an invalid
descriptor.

The fix simply removes the user count altogether and moves the fops
initialization to probe time such that it is only performed one time
for the life of the adapter. In the future, if the CXL services adopt
a private member for their context, that could be used to store the
adapter structure reference and cxlflash could revert to a model that
does not require an embedded fops.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: NDaniel Axtens <dja@axtens.net>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

The operator used to double the master context response delay
is incorrect and does not result in delay doubling.

To fix, use a left shift instead of the XOR operator.
Reported-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Following an adapter reset, the AFU RRQ that resides in host memory
holds stale data. This can lead to a condition where the RRQ interrupt
handler tries to process stale entries and/or endlessly loops due to an
out of sync generation bit.

To fix, the AFU RRQ in host memory needs to be cleared after each reset.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NDaniel Axtens <dja@axtens.net>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

There are several spelling and grammar mistakes throughout the
driver. Additionally there are a handful of places where there
are extra lines and unnecessary variables/statements. These are
a nuisance and pollute the driver.

Fix spelling and grammar issues. Update some comments for clarity and
consistency. Remove extra lines and a few unneeded variables/statements.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Sparse uncovered several errors with MMIO operations (accessing
directly) and handling endianness. These can cause issues when
running in different environments.

Introduce __iomem and proper endianness tags/swaps where
appropriate to make driver sparse clean.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Several function prologs have incorrect parameter names and return
code descriptions. This can lead to confusion when reviewing the
source and creates inaccurate documentation.

To remedy, update the function prologs to properly reflect parameter
names and return codes.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

The host reset handler is called with I/O already blocked, thus
there is no need to explicitly block and unblock I/O in the handler.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

When the device reset handler is entered while a reset operation
is taking place, the handler exits without actually sending a
reset (TMF) to the targeted device. This behavior is incorrect
as the device is not reset. Further complicating matters is the
fact that a success is returned even when the TMF was not sent.

To fix, the state is rechecked after coming out of the reset
state. When the state is normal, a TMF will be sent out.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

The workq can process work in parallel with a remove event, leading
to a condition where the workq handler can access freed memory.

To remedy, the workq should be terminated prior to freeing memory. Move
the termination call earlier in remove and use cancel_work_sync() instead
of flush_work() as there is not a need to process any scheduled work when
shutting down.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Currently, scsi_host_put() is being called prematurely in the
remove path and is missing entirely in an error cleanup path.
The former can lead to memory being freed too early with
subsequent access potentially corrupting data whilst the former
would result in a memory leak.

Move the usage on remove to be the last cleanup action taken
and introduce a call to scsi_host_put() in the one initialization
error path that does not use remove to cleanup.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

The AFU version is stored as a non-terminated string of bytes within
a 64-bit little-endian register. Presently the value is read directly
(no MMIO accessor) and is stored in a buffer that is not big enough
to contain a NULL terminator. Additionally the version obtained is not
evaluated against a known value to prevent usage with unsupported AFUs.
All of these deficiencies can lead to a variety of problems.

To remedy, use the correct MMIO accessor to read the version value into
a null-terminated buffer and add a check to prevent an incompatible AFU
from being used with this driver.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NDaniel Axtens <dja@axtens.net>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

At present, both ports must be online for the device to
configure properly. Remove this dependency and the unnecessary
internal LUN override logic as well. Additionally, as a refactoring
measure, change the return code variable name to match that used
throughout the driver.

With this change, the card will be able to configure even when the
link is down. At some later point when the link is transitioned to
'up', a link state change interrupt will trigger the port configuration.
Note that despite its void-like behavior, the function was left with a
return code for right now in case its behavior needs to be altered again
in the near future based on testing.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NDaniel Axtens <dja@axtens.net>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

A bug was introduced earlier in the development cycle when cleaning
up logic statements. Instead of skipping bits that are not set, set
bits are skipped, causing async interrupts to not be handled correctly.

To fix, simply add back in the proper evaluation for an unset bit.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Following a link up event, the LUNs available to the host may
have changed. Without rescanning the host, the LUN topology is
unknown to the user. In such a state, the user would be unable
to locate provisioned resources.

To remedy, the host should be rescanned after a link up event.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

The resid is incorrectly set which can lead to unnecessary retry
attempts by the stack. This is due to resid _always_ being set
using a value returned from the adapter. Instead, the value
should only be interpreted and set when in an underrun scenario.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Borrowing the TMF waitq's spinlock causes a stall condition when
waiting for the TMF to complete. To remedy, introduce our own spin
lock to serialize TMF and use the appropriate wait services.

Also add a timeout while waiting for a TMF completion. When a TMF
times out, report back a failure such that a bigger hammer reset
can occur.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

During run-time the driver can be very chatty and spam the system
kernel log. Various print statements can be limited and/or moved
to development-only mode. Additionally, numerous prints can be
converted to trace the corresponding device. Lastly, one spelling
correction was made: 'entra' to 'extra'.

The following changes were made:
 - pr_debug to pr_devel
 - pr_debug to pr_debug_ratelimited
 - pr_err to dev_err
 - pr_debug to dev_dbg
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Implement the following suggestions and add two new attributes
to allow for debugging the port LUN table.

 - use scnprintf() instead of snprintf()
 - use DEVICE_ATTR_RO and DEVICE_ATTR_RW
Suggested-by: NShane Seymour <shane.seymour@hp.com>
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Found during code inspection, that the following functions are not
being used outside of the file where they are defined. Make them static.

int cxlflash_send_cmd(struct afu *, struct afu_cmd *);
void cxlflash_wait_resp(struct afu *, struct afu_cmd *);
int cxlflash_afu_reset(struct cxlflash_cfg *);
struct afu_cmd *cxlflash_cmd_checkout(struct afu *);
void cxlflash_cmd_checkin(struct afu_cmd *);
void init_pcr(struct cxlflash_cfg *);
int init_global(struct cxlflash_cfg *);
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Limbo is not an accurate representation of this state and is
also not consistent with the terminology that other drivers
use to represent this concept. Rename the state and and its
associated waitq to 'reset'.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NDaniel Axtens <dja@axtens.net>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

During an EEH freeze event, certain CXL services should not be
called until after the hardware reset has taken place. Doing so
can result in unnecessary failures and possibly cause other ill
effects by triggering hardware accesses. This translates to a
requirement to quiesce all threads that may potentially use CXL
runtime service during this window. In particular, multiple ioctls
make use of the CXL services when acting on contexts on behalf of
the user. Thus, it is essential to 'drain' running ioctls _before_
proceeding with handling the EEH freeze event.

Create the ability to drain ioctls by wrapping the ioctl handler
call in a read semaphore and then implementing a small routine that
obtains the write semaphore, effectively creating a wait point for
all currently executing ioctls.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Reviewed-by: NDaniel Axtens <dja@axtens.net>
Reviewed-by: NTomas Henzl <thenzl@redhat.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

The queuecommand routine has a local dev pointer used for the
dev_* prints. The two prints that currently exist are tucked
under a debug define and thus can be left out. Use the actual
location instead of a local to avoid this warning.

This patch is intended to be applied after the "CXL Flash Error
Recovery and Superpipe" series.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

"port_sel" is a u64 so the shifting should also be a 64 bit shift.

Fixes: c21e0bbf ('cxlflash: Base support for IBM CXL Flash Adapter')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

The > should be >= or we read one element past the end of the array.

Fixes: c21e0bbf ('cxlflash: Base support for IBM CXL Flash Adapter')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Add support for physical LUN segmentation (virtual LUNs) to device
driver supporting the IBM CXL Flash adapter. This patch allows user
space applications to virtually segment a physical LUN into N virtual
LUNs, taking advantage of the translation features provided by this
adapter.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NMichael Neuling <mikey@neuling.org>
Reviewed-by: NWen Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Add superpipe supporting infrastructure to device driver for the IBM CXL
Flash adapter. This patch allows userspace applications to take advantage
of the accelerated I/O features that this adapter provides and bypass the
traditional filesystem stack.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NMichael Neuling <mikey@neuling.org>
Reviewed-by: NWen Xiong <wenxiong@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>

Introduce support for enhanced I/O error handling.

A device state is added to track 3 possible states of the device:

Normal - the device is operating normally and is fully operational

Limbo - the device is in a reset/recovery scenario and its operational
        status is paused

Failed/terminating - the device has either failed to be reset/recovered
                     or is being terminated (removed); it is no longer
                     operational

All operations are allowed when the device is operating normally. When the
device transitions to limbo state, I/O must be paused. To help accomplish
this, a wait queue is introduced where existing and new threads can wait
until the device is no longer in limbo. When coming out of limbo, threads
need to check the state and error out gracefully when encountering the
failed state. When the device transitions to the failed/terminating state,
normal operations are no longer allowed. Only specially designated
operations related to graceful cleanup are permitted.
Signed-off-by: NMatthew R. Ochs <mrochs@linux.vnet.ibm.com>
Signed-off-by: NManoj N. Kumar <manoj@linux.vnet.ibm.com>
Reviewed-by: NDaniel Axtens <dja@axtens.net>
Reviewed-by: NMichael Neuling <mikey@neuling.org>
Reviewed-by: NWen Xiong <wenxiong@linux.vnet.ibm.com>
Reviewed-by: NBrian King <brking@linux.vnet.ibm.com>
Signed-off-by: NJames Bottomley <JBottomley@Odin.com>