The current deadlock detection logic does not work reliably due to the
following early exit path:
/*
* Drop out, when the task has no waiters. Note,
* top_waiter can be NULL, when we are in the deboosting
* mode!
*/
if (top_waiter && (!task_has_pi_waiters(task) ||
top_waiter != task_top_pi_waiter(task)))
goto out_unlock_pi;
So this not only exits when the task has no waiters, it also exits
unconditionally when the current waiter is not the top priority waiter
of the task.
So in a nested locking scenario, it might abort the lock chain walk
and therefor miss a potential deadlock.
Simple fix: Continue the chain walk, when deadlock detection is
enabled.
We also avoid the whole enqueue, if we detect the deadlock right away
(A-A). It's an optimization, but also prevents that another waiter who
comes in after the detection and before the task has undone the damage
observes the situation and detects the deadlock and returns
-EDEADLOCK, which is wrong as the other task is not in a deadlock
situation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20140522031949.725272460@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The CONFIG_MIPS_CPS SMP implementation should be able to handle all
cases the CONFIG_MIPS_CMP implementation does, but without requiring
bootloader assistance. It is also required in order to make use of
features such as hotplug & cpuidle core power gating. Enable it by
default for Malta configs that previously enabled the now deprecated
CONFIG_MIPS_CMP, and disable the latter. The local version suffix "cmp"
is removed rather than replaced with "cps" since there are other ways to
tell that the CPS SMP implementation is in use (the "VPE topology" line
in the boot log being one).
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
This patch adds a cpuidle driver for systems based around the MIPS
Coherent Processing System (CPS) architecture. It supports four idle
states:
- The standard MIPS wait instruction.
- The non-coherent wait, clock gated & power gated states exposed by
the recently added pm-cps layer.
The pm-cps layer is used to enter all the deep idle states. Since cores
in the clock or power gated states cannot service interrupts, the
gic_send_ipi_single function is modified to send a power up command for
the appropriate core to the CPC in cases where the target CPU has marked
itself potentially incoherent.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Declaring this allows drivers which need to initialise each struct
cpuidle_device at initialisation time to make use of the structures
already defined in cpuidle.c, rather than having to wastefully define
their own.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
This patch simply includes the cpuidle Kconfig entries in preparation
for cpuidle drivers used on MIPS systems.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Defines a macro intended to allow trivial use of the regular MIPS wait
instruction from cpuidle drivers, which may simply invoke the macro
within their array of states.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Rather than hardcoding CCA=0x5 for secondary cores, re-use the CCA from
the boot CPU. This allows overrides of the CCA using the cca= kernel
parameter to take effect on all CPUs for consistency.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
This patch sets a default CCA suited for use with multi-core SMP on all
current MIPS CPS based systems. It may still be overriden by the cca=
argument on the kernel command line.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
If the user or bootloader sets the CCA to a value which is not suited
for multi-core SMP (ie. anything non-coherent) then limit the system to
using only a single core and warn the user.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
This patch adds support for offlining CPUs via hotplug when using the
CONFIG_MIPS_CPS SMP implementation. When a CPU is offlined one of 2
things will happen:
- If the CPU is part of a core which implements the MT ASE and there
is at least one other VPE online within that core then the VPE will
be halted by settings its TCHalt bit.
- Otherwise if supported the core will be powered down via the CPC.
- Otherwise the CPU will hang by executing an infinite loop.
Bringing CPUs back online is then a process of either clearing the
appropriate VPEs TCHalt bit or powering up the appropriate core via the
CPC. Throughout the process the struct core_boot_config vpe_mask field
must be maintained such that mips_cps_boot_vpes will start & stop the
correct VPEs.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
This patch adds code to generate entry & exit code for various low power
states available on systems based around the MIPS Coherent Processing
System architecture (ie. those with a Coherence Manager, Global
Interrupt Controller & for >=CM2 a Cluster Power Controller). States
supported are:
- Non-coherent wait. This state first leaves the coherent domain and
then executes a regular MIPS wait instruction. Power savings are
found from the elimination of coherency interventions between the
core and any other coherent requestors in the system.
- Clock gated. This state leaves the coherent domain and then gates
the clock input to the core. This removes all dynamic power from the
core but leaves the core at the mercy of another to restart its
clock. Register state is preserved, but the core can not service
interrupts whilst its clock is gated.
- Power gated. This deepest state removes all power input to the core.
All register state is lost and the core will restart execution from
its BEV when another core powers it back up. Because register state
is lost this state requires cooperation with the CONFIG_MIPS_CPS SMP
implementation in order for the core to exit the state successfully.
The code will detect which states are available on the current system
during boot & generate the entry/exit code for those states. This will
be used by cpuidle & hotplug implementations.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
The core which the CPC core-other region relates to is based upon the
core-local core-other addressing register. As its name suggests this
register is shared between all VPEs within a core, and if there is a
possibility that multiple VPEs within a core will attempt to access
another core simultaneously then locking is required. This wasn't
previously a problem with the only user being cpu0 during boot, but will
be an issue once hotplug is implemented & may race with other users such
as cpuidle.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
The start of mips_cps_core_entry is patched in order to provide the code
with the address of the CM register region at a point where it will be
running non-coherent with the rest of the system. However the cache
wasn't being flushed after that patching which could in principle lead
to secondary cores using an invalid CM base address.
The patching is moved to cps_prepare_cpus since local_flush_icache_range
has not been initialised at the point cps_smp_setup is called.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
The core power down state for cpuidle will require that the CPS SMP
implementation is in use. This patch provides a mips_cps_smp_in_use
function which determines whether or not the CPS SMP implementation is
currently in use.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
When hotplug and/or a powered down idle state are supported cases will
arise where a non-zero VPE must be brought online without VPE 0, and it
where multiple VPEs must be onlined simultaneously. This patch prepares
for that by:
- Splitting struct boot_config into core & VPE boot config structures,
allocated one per core or VPE respectively. This allows for multiple
VPEs to be onlined simultaneously without clobbering each others
configuration.
- Indicating which VPEs should be online within a core at any given
time using a bitmap. This allows multiple VPEs to be brought online
simultaneously and also indicates to VPE 0 whether it should halt
after starting any non-zero VPEs that should be online within the
core. For example if all VPEs within a core are offlined via hotplug
and the user onlines the second VPE within that core:
1) The core will be powered up.
2) VPE 0 will run from the BEV (ie. mips_cps_core_entry) to
initialise the core.
3) VPE 0 will start VPE 1 because its bit is set in the cores
bitmap.
4) VPE 0 will halt itself because its bit is clear in the cores
bitmap.
- Moving the core & VPE initialisation to assembly code which does not
make any use of the stack. This is because if a non-zero VPE is to
be brought online in a powered down core then when VPE 0 of that
core runs it may not have a valid stack, and even if it did then
it's messy to run through parts of generic kernel code on VPE 0
before starting the correct VPE.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
This patch allows use of the MT ASE yield instruction from uasm. It will
be used by a subsequent patch.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
This patch allows for use of the beq instruction with labels from uasm,
much as bne & others already do. It will be used by a subsequent patch.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
The opcode for the wait instruction within POOL32AXf was missing. This
patch adds it for use by a subsequent patch.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
The opcode for the sync instruction within POOL32AXf was missing. This
patch adds it for use by a subsequent patch.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
The opcode for the MT ASE yield instruction within the spec3 group was
missing. This patch adds it for use by a subsequent patch.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Define a macro to write to the current TCs TCHalt register. This will be
used by a subsequent patch.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
This is identical to kmap_coherent apart from the cache coherency
attribute used for the TLB entry, so kmap_coherent is abstracted to
kmap_prot which is then called for both kmap_coherent &
kmap_noncoherent. This will be used by a subsequent patch.
Suggested-by: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
The PPC fixes are important because they fix breakage that is new in 3.15.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"Small fixes for x86, slightly larger fixes for PPC, and a forgotten
s390 patch. The PPC fixes are important because they fix breakage
that is new in 3.15"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: s390: announce irqfd capability
KVM: x86: disable master clock if TSC is reset during suspend
KVM: vmx: disable APIC virtualization in nested guests
KVM guest: Make pv trampoline code executable
KVM: PPC: Book3S: ifdef on CONFIG_KVM_BOOK3S_32_HANDLER for 32bit
KVM: PPC: Book3S HV: Add missing code for transaction reclaim on guest exit
KVM: PPC: Book3S: HV: make _PAGE_NUMA take effect
Pull two powerpc fixes from Ben Herrenschmidt:
"Here's a pair of powerpc fixes for 3.15 which are also going to
stable.
One's a fix for building with newer binutils (the problem currently
only affects the BookE kernels but the affected macro might come back
into use on BookS platforms at any time). Unfortunately, the binutils
maintainer did a backward incompatible change to a construct that we
use so we have to add Makefile check.
The other one is a fix for CPUs getting stuck in kexec when running
single threaded. Since we routinely use kexec on power (including in
our newer bootloaders), I deemed that important enough"
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc, kexec: Fix "Processor X is stuck" issue during kexec from ST mode
powerpc: Fix 64 bit builds with binutils 2.24
Add the Microsoft Surface Pro 2 Type/Touch and default device hardware ID's
Set report quirk for the device in hid-sensor-hub
Signed-off-by: Reyad Attiyat <reyad.attiyat@gmail.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Mark new interfaces as idle to allow operations that require that
interfaces are idle to take place. Interface types that are always
not idle (like AP interfaces) will be set as not idle when they are
assigned a channel context.
Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Emmanuel Grumbach<emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
During strong signal fluctuations under high throughput, few consecutive
failed A-MPDU transmissions can easily trigger packet loss notification,
and thus (in AP mode) client disconnection.
Reduce the number of false positives by checking the A-MPDU status flag
and treating a failed A-MPDU as a single packet.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Doing so will lead to an oops for a p2p-dev interface, since it has
no netdev.
Cc: stable@vger.kernel.org
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
If the rate control algorithm uses a selection table, it
is leaked when the station is destroyed - fix that.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Reported-by: Christophe Prévotaux <cprevotaux@nltinc.com>
Fixes: 0d528d85c5 ("mac80211: improve the rate control API")
Cc: stable@vger.kernel.org # v3.10+
[add commit log entry, remove pointless NULL check]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit did an incorrect printk->pr_info conversion. If we were
converting to pr_info() we should lose the log_level parameter. The problem is
that this is called (indirectly) by show_regs_print_info(), which is called
with various log_levels (from _INFO clear to _EMERG). So we leave it as
a printk() call so the desired log_level is applied.
Not a full revert, as the other half of the patch is correct.
Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Tejun Heo <tj@kernel.org>
Both the cache flush state machine and the SCSI midlayer want to submit
requests from irq context, and the current per-request requeue_work
unfortunately causes corruption due to sharing with the csd field for
flushes. Replace them with a per-request_queue list of requests to
be requeued.
Based on an earlier test by Ming Lei.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Ming Lei <tom.leiming@gmail.com>
Tested-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
It can happen only when dentry_kill() is called with unlock_on_failure
equal to 0 - other callers had dentry pinned until the moment they've
got ->d_lock and DCACHE_DENTRY_KILLED is set only after lockref_mark_dead().
IOW, only one of three call sites of dentry_kill() might end up reaching
that code. Just move it there.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add device tree probing support to the 'pci-rcar-gen2' driver.
[Sergei: numerous fixes/cleanups/additions]
[bhelgaas: whitespace fix]
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Arnd Bergmann <arnd@arndb.de>
This switches the PCA953x driver over to using the gpiolib irqchip
helpers to handle the threaded interrups cascaded off this
GPIO chip.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Commit 41a55b4de3 ("floppy: silence warning during disk test") caused
bio.bi_flags being overwritten, and its initialization to BIO_UPTODATE
in bio_init() to be lost.
This was unnoticed until 7b7b68bba5 ("floppy: bail out in open() if
drive is not responding to block0 read"), because the error value wasn't
checked for in the bio completion callback.
Now we are actually looking at the error, and the loss of BIO_UPTODATE
causes EIO to be wrongly passed to the callback, which confuses the
FD_OPEN_SHOULD_FAIL_BIT logic.
Fix this by not destroying previous value of bi_flags when setting
BIO_QUIET.
Cc: Stephen Hemminger <shemminger@vyatta.com>
Reported-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Error handling in UFS driver is broken and resets the host controller
for fatal errors without re-initialization. Correct the fatal error
handling sequence according to UFS Host Controller Interface (HCI)
v1.1 specification.
o Processed requests which are completed w/wo error are reported to
SCSI layer and any pending commands that are not started are aborted
in the controller and re-queued into scsi mid-layer queue.
o Upon determining fatal error condition the host controller may hang
forever until a reset is applied. Block SCSI layer for sending new
requests and apply reset in a separate error handling work.
o SCSI is informed about the expected Unit-Attention exception from the
device for the immediate command after a reset so that the SCSI layer
take necessary steps to establish communication with the device.
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Reviewed-by: Yaniv Gardi <ygardi@codeaurora.org>
Tested-by: Dolev Raviv <draviv@codeaurora.org>
Acked-by: Vinayak Holikatti <vinholikatti@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
As of now SCSI initiated error handling is broken because,
the reset APIs don't try to bring back the device initialized and
ready for further transfers.
In case of timeouts, the scsi error handler takes care of handling aborts
and resets. Improve the error handling in such scenario by resetting the
device and host and re-initializing them in proper manner.
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Reviewed-by: Yaniv Gardi <ygardi@codeaurora.org>
Tested-by: Dolev Raviv <draviv@codeaurora.org>
Acked-by: Vinayak Holikatti <vinholikatti@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
There is a possible race condition in the hardware when the abort
command is issued to terminate the ongoing SCSI command as described
below:
- A bit in the door-bell register is set in the controller for a
new SCSI command.
- In some rare situations, before controller get a chance to issue
the command to the device, the software issued an abort command.
- If the device recieves abort command first then it returns success
because the command itself is not present.
- Now if the controller commits the command to device it will be
processed.
- Software thinks that command is aborted and proceed while still
the device is processing it.
- The software, controller and device may go out of sync because of
this race condition.
To avoid this, query task presence in the device before sending abort
task command so that after the abort operation, the command is guaranteed
to be non-existent in both controller and the device.
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Reviewed-by: Yaniv Gardi <ygardi@codeaurora.org>
Tested-by: Dolev Raviv <draviv@codeaurora.org>
Acked-by: Vinayak Holikatti <vinholikatti@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Currently, sending Task Management (TM) command to the card might
be broken in some scenarios as listed below:
Problem: If there are more than 8 TM commands the implementation
returns error to the caller.
Fix: Wait for one of the slots to be emptied and send the command.
Problem: Sometimes it is necessary for the caller to know the TM service
response code to determine the task status.
Fix: Propogate the service response to the caller.
Problem: If the TM command times out no proper error recovery is
implemented.
Fix: Clear the command in the controller door-bell register, so that
further commands for the same slot don't fail.
Problem: While preparing the TM command descriptor, the task tag used
should be unique across SCSI/NOP/QUERY/TM commands and not the
task tag of the command which the TM command is trying to manage.
Fix: Use a unique task tag instead of task tag of SCSI command.
Problem: Since the TM command involves H/W communication, abruptly ending
the request on kill interrupt signal might cause h/w malfunction.
Fix: Wait for hardware completion interrupt with TASK_UNINTERRUPTIBLE
set.
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Reviewed-by: Yaniv Gardi <ygardi@codeaurora.org>
Tested-by: Dolev Raviv <draviv@codeaurora.org>
Acked-by: Vinayak Holikatti <vinholikatti@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Fix many warnings with incorrect endian assumptions
which makes the code unportable to new architectures.
The UFS specification defines the byte order as big-endian
for UPIU structure and little-endian for the host controller
transfer/task management descriptors.
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Acked-by: Vinayak Holikatti <vinholikatti@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
rescan_hba_mode was defined as a u8 so could never be less than zero:
rescan_hba_mode = hpsa_hba_mode_enabled(h);
if (rescan_hba_mode < 0)
goto out;
Signed-off-by: Joe Handzik <joseph.t.handzik@hp.com>
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The sun3 drivers suffer from a whole bunch of duplicated code. Fix this
by following the g_NCR5380_mmio example. (Notionally, sun3_scsi relates to
sun3_scsi_vme in the same way that g_NCR5380 relates to g_NCR5380_mmio.)
Dead code is also removed: we now have working debug macros so
SUN3_SCSI_DEBUG is undesirable. Dead code within #ifdef OLD_DMA is also
dropped, consistent with sun3_scsi_vme.c.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Acked-by: Sam Creasey <sammy@sammy.net>
Signed-off-by: Christoph Hellwig <hch@lst.de>
