Now that we've split the pdev and DT probing logic from the runtime
management, let's move the former into its own file. We gain a few lines
due to the copyright header and includes, but this should keep the logic
clearly separated, and paves the way for adding ACPI support in a
similar fashion.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Tested-by: NJeremy Linton <jeremy.linton@arm.com>
[will: rename nr_irqs to avoid conflict with global variable]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Currently we request (and potentially free) all IRQs for a given PMU in
cpu_pmu_init(). This works for platform/DT probing today, but it doesn't
fit ACPI well as we don't have all our affinity data up-front.

In preparation for ACPI support, fold the IRQ request/free into
arm_pmu_device_probe(), which will remain specific to platform/DT
probing.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Tested-by: NJeremy Linton <jeremy.linton@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Currently we have functions to request/free all IRQs for a given PMU.
While this works today, this won't work for ACPI, where we don't know
the full set of IRQs up front, and need to request them separately.

To enable supporting ACPI, this patch splits out the cpu-local
request/free into new functions, allowing us to request/free individual
IRQs.

As this makes it possible/necessary to request a PPI once per cpu, an
additional check is added to detect mismatched PPIs. This shouldn't
matter for the DT / platform case, as we check this when parsing.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Tested-by: NJeremy Linton <jeremy.linton@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

For historical reasons, portions of the arm_pmu code use a cpu_pmu_
prefix rather than an armpmu_ prefix. While a minor annoyance, this
hasn't been a problem thusfar.

However, to enable ACPI support, we'll need to expose a few things in
header files, and we should aim to keep those consistently namespaced.
In preparation for exporting our IRQ request/free functions, rename
these to have an armpmu_ prefix. For consistency, the 'cpu_pmu'
parameter is also renamed to 'armpmu'.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Tested-by: NJeremy Linton <jeremy.linton@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

In armpmu_dispatch_irq() we look at arm_pmu::plat_device to acquire
platdata, so that we can defer to platform-specific IRQ handling,
required on some 32-bit parts. With the advent of ACPI we won't always
have a platform_device, and so we must avoid trying to dereference
fields from it.

This patch fixes up armpmu_dispatch_irq() to avoid doing so, introducing
a new armpmu_get_platdata() helper.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Tested-by: NJeremy Linton <jeremy.linton@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The ARM PMU framework code always uses armpmu_dispatch_irq as its common
IRQ handler. Passing this down from cpu_pmu_init() is somewhat
pointless, and gets in the way of refactoring.

This patch makes cpu_pmu_request_irqs() always use armpmu_dispatch_irq
as the handler when requesting IRQs, and removes the handler parameter
from its prototype.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Tested-by: NJeremy Linton <jeremy.linton@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Currently arm_pmu_device_probe contains probing logic specific to the
platform_device infrastructure, and some logic required to safely
register the PMU with various systems.

This patch factors out the logic relating to the registration of the
PMU. This makes arm_pmu_device_probe a little easier to read, and will
make it easier to reuse the logic for an ACPI-specific probing
mechanism.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Tested-by: NJeremy Linton <jeremy.linton@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Given we always want to initialise common fields on an allocated PMU,
this patch folds this common initialisation into armpmu_alloc(). This
will make it simpler to reuse this code for an ACPI-specific probe path.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Tested-by: NJeremy Linton <jeremy.linton@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

We expect an ARM PMU's init function to have a particular prototype,
which we open-code in a few places. This is less than ideal, considering
that we cast a void value to this type in one location, and a mismatch
could easily be missed.

Add a typedef so that we can ensure this is consistent.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Tested-by: NJeremy Linton <jeremy.linton@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

We currently disable the PMU temporarily in armpmu_add(). We may have
required this historically, but the perf core always disables an event's
PMU when calling event::pmu::add(), so this is not necessary.

We don't do similarly in armpmu_del(), or elsewhere, so this is
unnecessary and inconsistent, and only serves to confuse the reader.

Remove the pointless disable, simplifying armpmu_add() in the process.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Tested-by: NJeremy Linton <jeremy.linton@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

This adds a new dynamic PMU to the Perf Events framework to program
and control the L3 cache PMUs in some Qualcomm Technologies SOCs.

The driver supports a distributed cache architecture where the overall
cache for a socket is comprised of multiple slices each with its own PMU.
Access to each individual PMU is provided even though all CPUs share all
the slices. User space needs to aggregate to individual counts to provide
a global picture.

The driver exports formatting and event information to sysfs so it can
be used by the perf user space tools with the syntaxes:
   perf stat -a -e l3cache_0_0/read-miss/
   perf stat -a -e l3cache_0_0/event=0x21/
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NAgustin Vega-Frias <agustinv@codeaurora.org>
[will: fixed sparse issues]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

For historical reasons, we lazily request and free interrupts in the
arm pmu driver. This requires us to refcount use of the pmu (by way of
counting the active events) in order to request/free interrupts at the
correct times, which complicates the driver somewhat.

The existing logic is flawed, as it only considers currently online CPUs
when requesting, freeing, or managing the affinity of interrupts.
Intervening hotplug events can result in erroneous IRQ affinity, online
CPUs for which interrupts have not been requested, or offline CPUs whose
interrupts are still requested.

To fix this, this patch splits the requesting of interrupts from any
per-cpu management (i.e. per-cpu enable/disable, and configuration of
cpu affinity). We now request all interrupts up-front at probe time (and
never free them, since we never unregister PMUs).

The management of affinity, and per-cpu enable/disable now happens in
our cpu hotplug callback, ensuring it occurs consistently. This means
that we must now invoke the CPU hotplug callback at boot time in order
to configure IRQs, and since the callback also resets the PMU hardware,
we can remove the duplicate reset in the probe path.

This rework renders our event refcounting unnecessary, so this is
removed.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
[will: make armpmu_get_cpu_irq static]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When requesting or freeing interrupts, we use platform_get_irq() to find
relevant irqs, backing this up with additional information in an
optional irq_affinity table.

This means that our irq request and free paths are tied to a
platform_device, and our request path must jump through a number of
hoops in order to determine the required affinity of each interrupt.

Given that the affinity must be static, we can compute the affinity once
up-front at probe time, simplifying the irq request and free paths. By
recording interrupts in a per-cpu data structure, we simplify a few
paths, and permit a subsequent rework of the request and free paths.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
[will: rename local nr_irqs variable to avoid conflict with global]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

For historical reasons, we allocate per-cpu data associated with a PMU
rather late, in cpu_pmu_init, after we've parsed whatever hardware
information we were provided with.

In order to allow use to store some per-cpu data early in the probe
path, we need to allocate (and initialise) the per-cpu data earlier.
This patch reworks the way we allocate the pmu and associated per-cpu
data in order to make that possible.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
[will: make armpmu_{alloc,free} static
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
signed-off-by: NGiridhar Malavali <giridhar.malavali@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Current driver wait for FW to be in the ready state before
processing in-coming commands. For Arbitrated Loop or
Point-to- Point (not switch), FW Ready state can take a while.
FW will transition to ready state after all Nports have been
logged in. In the mean time, certain initiators have completed
the login and starts IO. Driver needs to start processing all
queues if FW is already started.
Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

For target mode, when new scsi command arrive, driver first performs
a look up of the SCSI Host. The current look up method is based on
the ALPA portion of the NPort ID. For Cisco switch, the ALPA can
not be used as the index. Instead, the new search method is based
on the full value of the Nport_ID via btree lib.
Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NGiridhar Malavali <giridhar.malavali@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The Mailbox interface is currently over subscribed. We like
to reserve the Mailbox interface for the chip managment and
link initialization. Any non essential Mailbox command will
be routed through the IOCB interface. The IOCB interface is
able to absorb more commands.

Following commands are being routed through IOCB interface

- Get ID List (007Ch)
- Get Port DB (0064h)
- Get Link Priv Stats (006Dh)
Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Signed-off-by: NAnil Gurumurthy <anil.gurumurthy@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Add routines to support T10 DIF tag.
Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NAnil Gurumurthy <anil.gurumurthy@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

If the remote port have started the login process, then the
PLOGI and PRLI should be back to back. Driver will allow
the remote port to complete the process. For the case where
the remote port decide to back off from sending PRLI, this
local port sets an expiration timer for the PRLI. Once the
expiration time passes, the relogin retry logic is allowed
to go through and perform login with the remote port.
Signed-off-by: NQuinn Tran <quinn.tran@qlogic.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The main lock that needs to be held for CMD or TMR submission
to upper layer is the sess_lock. The sess_lock is used to
serialize cmd submission and session deletion. The addition
of hardware_lock being held is not necessary. This patch removes
hardware_lock dependency from CMD/TMR submission.

Use hardware_lock only for error response in this case.

Path1
       CPU0                    CPU1
       ----                    ----
  lock(&(&ha->tgt.sess_lock)->rlock);
                               lock(&(&ha->hardware_lock)->rlock);
                               lock(&(&ha->tgt.sess_lock)->rlock);
  lock(&(&ha->hardware_lock)->rlock);

Path2/deadlock
*** DEADLOCK ***
Call Trace:
dump_stack+0x85/0xc2
print_circular_bug+0x1e3/0x250
__lock_acquire+0x1425/0x1620
lock_acquire+0xbf/0x210
_raw_spin_lock_irqsave+0x53/0x70
qlt_sess_work_fn+0x21d/0x480 [qla2xxx]
process_one_work+0x1f4/0x6e0

Cc: <stable@vger.kernel.org>
Cc: Bart Van Assche <Bart.VanAssche@sandisk.com>
Reported-by: NBart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Normally, ABTS is sent to Target Core as Task MGMT command.
In the case of error, qla2xxx needs to send response, hardware_lock
is required to prevent request queue corruption.

Cc: <stable@vger.kernel.org>
Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

When FW notify driver or driver detects low FW resource,
driver tries to send out Busy SCSI Status to tell Initiator
side to back off. During the send process, the lock was not held.

Cc: <stable@vger.kernel.org>
Signed-off-by: NQuinn Tran <quinn.tran@qlogic.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Cc: <stable@vger.kernel.org>
Signed-off-by: NQuinn Tran <quinn.tran@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Cc: <stable@vger.kernel.org>
Signed-off-by: NJoe Carnuccio <joe.carnuccio@cavium.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Instead of putting cmd_time_out under ../target/core/user_0/foo/control,
which has historically been used by parameters needed for initial
backend device configuration, go ahead and move cmd_time_out into
a backend device attribute.

In order to do this, tcmu_module_init() has been updated to create
a local struct configfs_attribute **tcmu_attrs, that is based upon
the existing passthrough_attrib_attrs along with the new cmd_time_out
attribute.  Once **tcm_attrs has been setup, go ahead and point
it at tcmu_ops->tb_dev_attrib_attrs so it's picked up by target-core.

Also following MNC's previous change, ->cmd_time_out is stored in
milliseconds but exposed via configfs in seconds.  Also, note this
patch restricts the modification of ->cmd_time_out to before +
after the TCMU device has been configured, but not while it has
active fabric exports.

Cc: Mike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

A single daemon could implement multiple types of devices
using multuple types of real devices that may not support
restarting from crashes and/or handling tcmu timeouts. This
makes the cmd timeout configurable, so handlers that do not
support it can turn if off for now.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This adds a helper to check if the dev was configured. It
will be used in the next patch to prevent updates to some
config settings after the device has been setup.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This fixes the following races:

1. core_alua_do_transition_tg_pt could have read
tg_pt_gp_alua_access_state and gone into this if chunk:

if (!explicit &&
        atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state) ==
           ALUA_ACCESS_STATE_TRANSITION) {

and then core_alua_do_transition_tg_pt_work could update the
state. core_alua_do_transition_tg_pt would then only set
tg_pt_gp_alua_pending_state and the tg_pt_gp_alua_access_state would
not get updated with the second calls state.

2. core_alua_do_transition_tg_pt could be setting
tg_pt_gp_transition_complete while the tg_pt_gp_transition_work
is already completing. core_alua_do_transition_tg_pt then waits on the
completion that will never be called.

To handle these issues, we just call flush_work which will return when
core_alua_do_transition_tg_pt_work has completed so there is no need
to do the complete/wait. And, if core_alua_do_transition_tg_pt_work
was running, instead of trying to sneak in the state change, we just
schedule up another core_alua_do_transition_tg_pt_work call.

Note that this does not handle a possible race where there are multiple
threads call core_alua_do_transition_tg_pt at the same time. I think
we need a mutex in target_tg_pt_gp_alua_access_state_store.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

Userspace target_core_user handlers like tcmu-runner may want to set the
ALUA state to transitioning while it does implicit transitions. This
patch allows that state when set from configfs.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

The implicit transition time tells initiators the min time
to wait before timing out a transition. We currently schedule
the transition to occur in tg_pt_gp_implicit_trans_secs
seconds so there is no room for delays. If
core_alua_do_transition_tg_pt_work->core_alua_update_tpg_primary_metadata
needs to write out info to a remote file, then the initiator can
easily time out the operation.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

If tcmu-runner is processing a STPG and needs to change the kernel's
ALUA state then we cannot use the same work queue for task management
requests and ALUA transitions, because we could deadlock. The problem
occurs when a STPG times out before tcmu-runner is able to
call into target_tg_pt_gp_alua_access_state_store->
core_alua_do_port_transition -> core_alua_do_transition_tg_pt ->
queue_work. In this case, the tmr is on the work queue waiting for
the STPG to complete, but the STPG transition is now queued behind
the waiting tmr.

Note:
This bug will also be fixed by this patch:
http://www.spinics.net/lists/target-devel/msg14560.html
which switches the tmr code to use the system workqueues.

For both, I am not sure if we need a dedicated workqueue since
it is not a performance path and I do not think we need WQ_MEM_RECLAIM
to make forward progress to free up memory like the block layer does.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

We do not setup the LU group for pscsi devices, so if you write
a state to alua_access_state that will cause a transition you will
get a NULL pointer dereference.

This patch will fail attempts to try and transition the path
for backend devices that set the TRANSPORT_FLAG_PASSTHROUGH_ALUA
flag.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch allows passthrough backends to use the core/base LIO
ALUA setup and state checks, but still handle the execution of
commands.

This will allow the target_core_user module to execute STPG and RTPG
in userspace, and not have to duplicate the ALUA state checks, path
information (needed so we can check if command is executable on
specific paths) and setup (rtslib sets/updates the configfs ALUA
interface like it does for iblock or file).

For STPG, the target_core_user userspace daemon, tcmu-runner will
still execute the STPG, and to update the core/base LIO state it
will use the existing configfs interface. For RTPG, tcmu-runner
will loop over configfs and/or cache the state.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

We only were returing failure if the last opt to be parsed failed.
This has a return failure when we first detect a failure.
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

tcmu hard codes the hw_max_sectors to 128 which is a litle small.
Userspace uses the max_sectors to report the optimal IO size and
some initiators perform better with larger IOs (open-iscsi seems
to do better with 256 to 512 depending on the test).

(Fix do not display hw max sectors twice - MNC)
Signed-off-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

All in-tree fabric drivers provide a tfo->check_stop_free(),
so there is no need to do the extra check within existing
transport_cmd_check_stop_to_fabric() code.

Just to be sure, add a check in target_fabric_tf_ops_check()
to notify any out-of-tree drivers that might be missing it.
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>