When a USB device attached to a root-hub port sends a wakeup request
to a sleeping system, we do not report the wakeup event to the PM
core. This is because a system resume involves waking up all
suspended USB ports as quickly as possible; without the normal
USB_RESUME_TIMEOUT delay, the host controller driver doesn't set the
USB_PORT_STAT_C_SUSPEND flag and so usb_port_resume() doesn't realize
that a wakeup request was received.
However, some environments (such as Chrome OS) want to have all wakeup
events reported so they can be ascribed to the appropriate device. To
accommodate these environments, this patch adds a new routine to the
hub driver and a corresponding new HCD method to be used when a root
hub resumes. The HCD method returns a bitmap of ports that have
initiated a wakeup signal but not yet completed resuming. The hub
driver can then report to the PM core that the child devices attached
to these ports initiated a wakeup event.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Suggested-by: Anshuman Gupta <anshuman.gupta@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Sometimes memory resource may be overlapping with
SystemMemory Operation Region by design, for example if the
memory region is used as a mailbox for communication with a
firmware in the system. One occasion of such mailboxes is
USB Type-C Connector System Software Interface (UCSI).
With regions like that, it is important that the driver is
able to map the memory with the requirements it has. For
example, the driver should be allowed to map the memory as
non-cached memory. However, if the operation region has been
accessed before the driver has mapped the memory, the memory
has been marked as write-back by the time the driver is
loaded. That means the driver will fail to map the memory
if it expects non-cached memory.
To work around the problem, introducing helper that the
drivers can use to temporarily deactivate (unmap)
SystemMemory Operation Regions that overlap with their
IO memory.
Fixes: 8243edf441 ("usb: typec: ucsi: Add ACPI driver")
Cc: stable@vger.kernel.org
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Detected on the Dell XPS 9365.
The laptop has 2 devices that benefit from the hid-generic auto-unbinding.
When those 2 devices are presented to the userspace, udev loads both wacom and
hid-multitouch. When this happens, the code in __hid_bus_reprobe_drivers() is
called concurrently and the second device gets reprobed twice.
An other bug in the power_supply subsystem prevent to remove the wacom driver
if it just finished its initialization, which basically kills the wacom node.
[jkosina@suse.cz: reformat changelog a bit]
Fixes c17a7476e4 ("HID: core: rewrite the hid-generic automatic unbind")
Cc: stable@vger.kernel.org # v4.17
Tested-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
With the special case handling for Blackfin and Metag was removed by
commit 94e58e0ac3 ("export.h: remove code for prefixing symbols with
underscore"), VMLINUX_SYMBOL_STR() is now equivalent to __stringify().
Replace the remaining usages to prepare for the entire removal of
VMLINUX_SYMBOL_STR().
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Pull networking fixes from David Miller:
1) Fix netpoll OOPS in r8169, from Ville Syrjälä.
2) Fix bpf instruction alignment on powerpc et al., from Eric Dumazet.
3) Don't ignore IFLA_MTU attribute when creating new ipvlan links. From
Xin Long.
4) Fix use after free in AF_PACKET, from Eric Dumazet.
5) Mis-matched RTNL unlock in xen-netfront, from Ross Lagerwall.
6) Fix VSOCK loopback on big-endian, from Claudio Imbrenda.
7) Missing RX buffer offset correction when computing DMA addresses in
mvneta driver, from Antoine Tenart.
8) Fix crashes in DCCP's ccid3_hc_rx_send_feedback, from Eric Dumazet.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (34 commits)
sfc: make function efx_rps_hash_bucket static
strparser: Corrected typo in documentation.
qmi_wwan: add support for the Dell Wireless 5821e module
cxgb4: when disabling dcb set txq dcb priority to 0
net_sched: remove a bogus warning in hfsc
net: dccp: switch rx_tstamp_last_feedback to monotonic clock
net: dccp: avoid crash in ccid3_hc_rx_send_feedback()
net: Remove depends on HAS_DMA in case of platform dependency
MAINTAINERS: Add file patterns for dsa device tree bindings
net: mscc: make sparse happy
net: mvneta: fix the Rx desc DMA address in the Rx path
Documentation: e1000: Fix docs build error
Documentation: e100: Fix docs build error
Documentation: e1000: Use correct heading adornment
Documentation: e100: Use correct heading adornment
ipv6: mcast: fix unsolicited report interval after receiving querys
vhost_net: validate sock before trying to put its fd
VSOCK: fix loopback on big-endian systems
net: ethernet: ti: davinci_cpdma: make function cpdma_desc_pool_create static
xen-netfront: Update features after registering netdev
...
The DT node passed here isn't necessarily an OPP node, as this routine
can also be used for cases where the "required-opps" property is present
directly in the device's node. Rename it.
This also removes a stale comment.
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
linux/iio/buffer-dma.h was not updated to when length was changed to
unsigned int.
Fixes: c043ec1ca5 ("iio:buffer: make length types match kfifo types")
Signed-off-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
struct itimerspec is not y2038-safe.
Introduce a new struct __kernel_itimerspec based on the kernel internal
y2038-safe struct itimerspec64.
The definition of struct __kernel_itimerspec includes two struct
__kernel_timespec.
Since struct __kernel_timespec has the same representation in native and
compat modes, so does struct __kernel_itimerspec. This helps have a common
entry point for syscalls using struct __kernel_itimerspec.
New y2038-safe syscalls will use this new type. Since most of the new
syscalls are just an update to the native syscalls with the type update,
place the new definition under CONFIG_64BIT_TIME. This helps architectures
that do not support the above config to keep using the old definition of
struct itimerspec.
Also change the get/put_itimerspec64 to use struct__kernel_itimerspec.
This will help 32 bit architectures to use the new syscalls when
architectures select CONFIG_64BIT_TIME.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: arnd@arndb.de
Cc: viro@zeniv.linux.org.uk
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-api@vger.kernel.org
Cc: y2038@lists.linaro.org
Link: https://lkml.kernel.org/r/20180617051144.29756-2-deepa.kernel@gmail.com
Pull rseq fixes from Thomas Gleixer:
"A pile of rseq related fixups:
- Prevent infinite recursion when delivering SIGSEGV
- Remove the abort of rseq critical section on fork() as syscalls
inside rseq critical sections are explicitely forbidden. So no
point in doing the abort on the child.
- Align the rseq structure on 32 bytes in the ARM selftest code.
- Fix file permissions of the test script"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rseq: Avoid infinite recursion when delivering SIGSEGV
rseq/cleanup: Do not abort rseq c.s. in child on fork()
rseq/selftests/arm: Align 'struct rseq_cs' on 32 bytes
rseq/selftests: Make run_param_test.sh executable
Pull core fixes from Thomas Gleixner:
"Two tiny fixes:
- Add the missing machine_real_restart() to objtools noreturn list so
it stops complaining
- Fix a trivial comment typo"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
kernel.h: Fix a typo in comment
objtool: Add machine_real_restart() to the noreturn list
Pull x86 fixes from Thomas Gleixner:
"A set of fixes for x86:
- Make Xen PV guest deal with speculative store bypass correctly
- Address more fallout from the 5-Level pagetable handling. Undo an
__initdata annotation to avoid section mismatch and malfunction
when post init code would touch the freed variable.
- Handle exception fixup in math_error() before calling notify_die().
The reverse call order incorrectly triggers notify_die() listeners
for soemthing which is handled correctly at the site which issues
the floating point instruction.
- Fix an off by one in the LLC topology calculation on AMD
- Handle non standard memory block sizes gracefully un UV platforms
- Plug a memory leak in the microcode loader
- Sanitize the purgatory build magic
- Add the x86 specific device tree bindings directory to the x86
MAINTAINER file patterns"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Fix 'no5lvl' handling
Revert "x86/mm: Mark __pgtable_l5_enabled __initdata"
x86/CPU/AMD: Fix LLC ID bit-shift calculation
MAINTAINERS: Add file patterns for x86 device tree bindings
x86/microcode/intel: Fix memleak in save_microcode_patch()
x86/platform/UV: Add kernel parameter to set memory block size
x86/platform/UV: Use new set memory block size function
x86/platform/UV: Add adjustable set memory block size function
x86/build: Remove unnecessary preparation for purgatory
Revert "kexec/purgatory: Add clean-up for purgatory directory"
x86/xen: Add call of speculative_store_bypass_ht_init() to PV paths
x86: Call fixup_exception() before notify_die() in math_error()
Pull locking fixes from Thomas Gleixner:
"A set of fixes and updates for the locking code:
- Prevent lockdep from updating irq state within its own code and
thereby confusing itself.
- Buid fix for older GCCs which mistreat anonymous unions
- Add a missing lockdep annotation in down_read_non_onwer() which
causes up_read_non_owner() to emit a lockdep splat
- Remove the custom alpha dec_and_lock() implementation which is
incorrect in terms of ordering and use the generic one.
The remaining two commits are not strictly fixes. They provide irqsave
variants of atomic_dec_and_lock() and refcount_dec_and_lock(). These
are required to merge the relevant updates and cleanups into different
maintainer trees for 4.19, so routing them into mainline without
actual users is the sanest approach.
They should have been in -rc1, but last weekend I took the liberty to
just avoid computers in order to regain some mental sanity"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/qspinlock: Fix build for anonymous union in older GCC compilers
locking/lockdep: Do not record IRQ state within lockdep code
locking/rwsem: Fix up_read_non_owner() warning with DEBUG_RWSEMS
locking/refcounts: Implement refcount_dec_and_lock_irqsave()
atomic: Add irqsave variant of atomic_dec_and_lock()
alpha: Remove custom dec_and_lock() implementation
Pull irq fixes from Thomas Gleixner:
"A set of fixes mostly for the ARM/GIC world:
- Fix the MSI affinity handling in the ls-scfg irq chip driver so it
updates and uses the effective affinity mask correctly
- Prevent binding LPIs to offline CPUs and respect the Cavium erratum
which requires that LPIs which belong to an offline NUMA node are
not bound to a CPU on a different NUMA node.
- Free only the amount of allocated interrupts in the GIC-V2M driver
instead of trying to free log2(nrirqs).
- Prevent emitting SYNC and VSYNC targetting non existing interrupt
collections in the GIC-V3 ITS driver
- Ensure that the GIV-V3 interrupt redistributor is correctly
reprogrammed on CPU hotplug
- Remove a stale unused helper function"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqdesc: Delete irq_desc_get_msi_desc()
irqchip/gic-v3-its: Fix reprogramming of redistributors on CPU hotplug
irqchip/gic-v3-its: Only emit VSYNC if targetting a valid collection
irqchip/gic-v3-its: Only emit SYNC if targetting a valid collection
irqchip/gic-v3-its: Don't bind LPI to unavailable NUMA node
irqchip/gic-v2m: Fix SPI release on error path
irqchip/ls-scfg-msi: Fix MSI affinity handling
genirq/debugfs: Add missing IRQCHIP_SUPPORTS_LEVEL_MSI debug
Pull block fixes from Jens Axboe:
- Further timeout fixes. We aren't quite there yet, so expect another
round of fixes for that to completely close some of the IRQ vs
completion races. (Christoph/Bart)
- Set of NVMe fixes from the usual suspects, mostly error handling
- Two off-by-one fixes (Dan)
- Another bdi race fix (Jan)
- Fix nbd reconfigure with NBD_DISCONNECT_ON_CLOSE (Doron)
* tag 'for-linus-20180623' of git://git.kernel.dk/linux-block:
blk-mq: Fix timeout handling in case the timeout handler returns BLK_EH_DONE
bdi: Fix another oops in wb_workfn()
lightnvm: Remove depends on HAS_DMA in case of platform dependency
nvme-pci: limit max IO size and segments to avoid high order allocations
nvme-pci: move nvme_kill_queues to nvme_remove_dead_ctrl
nvme-fc: release io queues to allow fast fail
nbd: Add the nbd NBD_DISCONNECT_ON_CLOSE config flag.
block: sed-opal: Fix a couple off by one bugs
blk-mq-debugfs: Off by one in blk_mq_rq_state_name()
nvmet: reset keep alive timer in controller enable
nvme-rdma: don't override opts->queue_size
nvme-rdma: Fix command completion race at error recovery
nvme-rdma: fix possible free of a non-allocated async event buffer
nvme-rdma: fix possible double free condition when failing to create a controller
Revert "block: Add warning for bi_next not NULL in bio_endio()"
block: fix timeout changes for legacy request drivers
syzbot is reporting NULL pointer dereference at wb_workfn() [1] due to
wb->bdi->dev being NULL. And Dmitry confirmed that wb->state was
WB_shutting_down after wb->bdi->dev became NULL. This indicates that
unregister_bdi() failed to call wb_shutdown() on one of wb objects.
The problem is in cgwb_bdi_unregister() which does cgwb_kill() and thus
drops bdi's reference to wb structures before going through the list of
wbs again and calling wb_shutdown() on each of them. This way the loop
iterating through all wbs can easily miss a wb if that wb has already
passed through cgwb_remove_from_bdi_list() called from wb_shutdown()
from cgwb_release_workfn() and as a result fully shutdown bdi although
wb_workfn() for this wb structure is still running. In fact there are
also other ways cgwb_bdi_unregister() can race with
cgwb_release_workfn() leading e.g. to use-after-free issues:
CPU1 CPU2
cgwb_bdi_unregister()
cgwb_kill(*slot);
cgwb_release()
queue_work(cgwb_release_wq, &wb->release_work);
cgwb_release_workfn()
wb = list_first_entry(&bdi->wb_list, ...)
spin_unlock_irq(&cgwb_lock);
wb_shutdown(wb);
...
kfree_rcu(wb, rcu);
wb_shutdown(wb); -> oops use-after-free
We solve these issues by synchronizing writeback structure shutdown from
cgwb_bdi_unregister() with cgwb_release_workfn() using a new mutex. That
way we also no longer need synchronization using WB_shutting_down as the
mutex provides it for CONFIG_CGROUP_WRITEBACK case and without
CONFIG_CGROUP_WRITEBACK wb_shutdown() can be called only once from
bdi_unregister().
Reported-by: syzbot <syzbot+4a7438e774b21ddd8eca@syzkaller.appspotmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
When delivering a signal to a task that is using rseq, we call into
__rseq_handle_notify_resume() so that the registers pushed in the
sigframe are updated to reflect the state of the restartable sequence
(for example, ensuring that the signal returns to the abort handler if
necessary).
However, if the rseq management fails due to an unrecoverable fault when
accessing userspace or certain combinations of RSEQ_CS_* flags, then we
will attempt to deliver a SIGSEGV. This has the potential for infinite
recursion if the rseq code continuously fails on signal delivery.
Avoid this problem by using force_sigsegv() instead of force_sig(), which
is explicitly designed to reset the SEGV handler to SIG_DFL in the case
of a recursive fault. In doing so, remove rseq_signal_deliver() from the
internal rseq API and have an optional struct ksignal * parameter to
rseq_handle_notify_resume() instead.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: peterz@infradead.org
Cc: paulmck@linux.vnet.ibm.com
Cc: boqun.feng@gmail.com
Link: https://lkml.kernel.org/r/1529664307-983-1-git-send-email-will.deacon@arm.com
For dependencies, branch based on 'mellanox/mlx5-next' of
git://git.kernel.org/pub/scm/linux/kernel/git/mellanox/linux.git
Pull RoCE ICRC counters from Leon Romanovsky:
====================
This series exposes RoCE ICRC counter through existing RDMA hw_counters
sysfs interface.
The first patch has all HW definitions in mlx5_ifc.h file and second patch
is the actual counter implementation.
====================
* branch 'icrc-counter':
IB/mlx5: Support RoCE ICRC encapsulated error counter
net/mlx5: Add RoCE RX ICRC encapsulated counter
When receiving multiple packets with the same ts ecr value, only try
to compute rcv_rtt sample with the earliest received packet.
This is because the rcv_rtt calculated by later received packets
could possibly include long idle time or other types of delay.
For example:
(1) server sends last packet of reply with TS val V1
(2) client ACKs last packet of reply with TS ecr V1
(3) long idle time passes
(4) client sends next request data packet with TS ecr V1 (again!)
At this time, the rcv_rtt computed on server with TS ecr V1 will be
inflated with the idle time and should get ignored.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Using rht_dereference_bucket() to dereference
->future_tbl looks like a type error, and could be confusing.
Using rht_dereference_rcu() to test a pointer for NULL
adds an unnecessary barrier - rcu_access_pointer() is preferred
for NULL tests when no lock is held.
This uses 3 different ways to access ->future_tbl.
- if we know the mutex is held, use rht_dereference()
- if we don't hold the mutex, and are only testing for NULL,
use rcu_access_pointer()
- otherwise (using RCU protection for true dereference),
use rht_dereference_rcu().
Note that this includes a simplification of the call to
rhashtable_last_table() - we don't do an extra dereference
before the call any more.
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The 'ht' and 'hash' arguments to INIT_RHT_NULLS_HEAD() are
no longer used - so drop them. This allows us to also
remove the nhash argument from nested_table_alloc().
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This "feature" is unused, undocumented, and untested and so doesn't
really belong. A patch is under development to properly implement
support for detecting when a search gets diverted down a different
chain, which the common purpose of nulls markers.
This patch actually fixes a bug too. The table resizing allows a
table to grow to 2^31 buckets, but the hash is truncated to 27 bits -
any growth beyond 2^27 is wasteful an ineffective.
This patch results in NULLS_MARKER(0) being used for all chains,
and leaves the use of rht_is_a_null() to test for it.
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Due to the use of rhashtables in net namespaces,
rhashtable.h is included in lots of the kernel,
so a small changes can required a large recompilation.
This makes development painful.
This patch splits out rhashtable-types.h which just includes
the major type declarations, and does not include (non-trivial)
inline code. rhashtable.h is no longer included by anything
in the include/ directory.
Common include files only include rhashtable-types.h so a large
recompilation is only triggered when that changes.
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull NFS client bugfixes from Trond Myklebust:
"Hightlights include:
- fix an rcu deadlock in nfs_delegation_find_inode()
- fix NFSv4 deadlocks due to not freeing the session slot in
layoutget
- don't send layoutreturn if the layout is already invalid
- prevent duplicate XID allocation
- flexfiles: Don't tie up all the rpciod threads in resends"
* tag 'nfs-for-4.18-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
pNFS/flexfiles: Process writeback resends from nfsiod context as well
pNFS/flexfiles: Don't tie up all the rpciod threads in resends
sunrpc: Prevent duplicate XID allocation
pNFS: Don't send layoutreturn if the layout is already invalid
pNFS: Always free the session slot on error in nfs4_layoutget_handle_exception
NFS: Fix an rcu deadlock in nfs_delegation_find_inode()
Add capability bit in PCAM register and RoCE ICRC error counter
to PPCNT register.
Signed-off-by: Talat Batheesh <talatb@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
The ifdeffery for atomic*_{fetch_,}andnot() is unlike that for all the
other atomics. If atomic*_andnot() is not defined, the corresponding
atomic*_fetch_andnot() is assumed to not be defined.
Additionally, the fallbacks for the various ordering cases are written
much later in atomic.h as static inlines.
This isn't problematic today, but gets in the way of scripting the
generation of atomics. To prepare for scripting, this patch:
* Switches to separate ifdefs for atomic*_andnot() and
atomic*_fetch_andnot(), updating implementations as appropriate.
* Moves the fallbacks into the standards ifdefs, as macro expansions
rather than static inlines.
* Removes trivial andnot implementations from architectures, where these
are superseded by core code.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-19-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The conditional inc/dec ops differ for atomic_t and atomic64_t:
- atomic_inc_unless_positive() is optional for atomic_t, and doesn't exist for atomic64_t.
- atomic_dec_unless_negative() is optional for atomic_t, and doesn't exist for atomic64_t.
- atomic_dec_if_positive is optional for atomic_t, and is mandatory for atomic64_t.
Let's make these consistently optional for both. At the same time, let's
clean up the existing fallbacks to use atomic_try_cmpxchg().
The instrumented atomics are updated accordingly.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-18-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Some of the atomics return the result of a test applied after the atomic
operation, and almost all architectures implement these as trivial
wrappers around the underlying atomic. Specifically:
* <atomic>_inc_and_test(v) is (<atomic>_inc_return(v) == 0)
* <atomic>_dec_and_test(v) is (<atomic>_dec_return(v) == 0)
* <atomic>_sub_and_test(i, v) is (<atomic>_sub_return(i, v) == 0)
* <atomic>_add_negative(i, v) is (<atomic>_add_return(i, v) < 0)
Rather than have these definitions duplicated in all architectures, with
minor inconsistencies in formatting and documentation, let's make these
operations optional, with default fallbacks as above. Implementations
must now provide a preprocessor symbol.
The instrumented atomics are updated accordingly.
Both x86 and m68k have custom implementations, which are left as-is,
given preprocessor symbols to avoid being overridden.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-16-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Architectures with atomic64_fetch_add_unless() provide a preprocessor
symbol if they do so, and all other architectures have trivial C
implementations of atomic64_add_unless() which are near-identical.
Let's unify the trivial definitions of atomic64_fetch_add_unless() in
<linux/atomic.h>, so that we always have both
atomic64_fetch_add_unless() and atomic64_add_unless() with less
boilerplate code.
This means that atomic64_add_unless() is always implemented in core
code, and the instrumented atomics are updated accordingly.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-15-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Several architectures these have a near-identical implementation based
on atomic_read() and atomic_cmpxchg() which we can instead define in
<linux/atomic.h>, so let's do so, using something close to the existing
x86 implementation with try_cmpxchg().
Where an architecture provides its own atomic_fetch_add_unless(), it
must define a preprocessor symbol for it. The instrumented atomics are
updated accordingly.
Note that arch/arc's existing atomic_fetch_add_unless() had redundant
barriers, as these are already present in its atomic_cmpxchg()
implementation.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet Gupta <vgupta@synopsys.com>
Link: https://lore.kernel.org/lkml/20180621121321.4761-7-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We define a trivial fallback for atomic_inc_not_zero(), but don't do
the same for atomic64_inc_not_zero(), leading most architectures to
define the same boilerplate.
Let's add a fallback in <linux/atomic.h>, and remove the redundant
implementations. Note that atomic64_add_unless() is always defined in
<linux/atomic.h>, and promotes its arguments to the requisite types, so
we need not do this explicitly.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-6-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Some of the atomics return a status value, which is a boolean value
describing whether the operation was performed. To make it clear that
this is a boolean value, let's update the common fallbacks to return
bool, fixing up the return values and comments likewise.
At the same time, let's simplify the description of the operations in
their respective comments.
The instrumented atomics and generic atomic64 implementation are updated
accordingly.
Note that atomic64_dec_if_positive() doesn't follow the usual test op
pattern, and returns the would-be decremented value. This is not
changed.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-5-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While documentation suggests atomic_inc_not_zero_hint() will perform better
than atomic_inc_not_zero(), this is unlikely to be the case. No architectures
implement atomic_inc_not_zero_hint() directly, and thus it either falls back to
atomic_inc_not_zero(), or a loop using atomic_cmpxchg().
Whenever the hint does not match the value in memory, the repeated use of
atomic_cmpxchg() will be more expensive than the read that
atomic_inc_not_zero_hint() attempts to avoid. For architectures with LL/SC
atomics, a read cannot be avoided, and it would always be better to use
atomic_inc_not_zero() directly. For other architectures, their own
atomic_inc_not_zero() is likely to be more optimal than an atomic_cmpxchg()
loop regardless.
Generally, atomic_inc_not_zero_hint() is liable to perform worse than
atomic_inc_not_zero(). Further, atomic_inc_not_zero_hint() only exists
for atomic_t, and not atomic64_t or atomic_long_t, and there is only one
user in the kernel tree.
Given all this, let's remove atomic_inc_not_zero_hint(), and migrate the
existing user over to atomic_inc_not_zero().
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-4-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While __atomic_add_unless() was originally intended as a building-block
for atomic_add_unless(), it's now used in a number of places around the
kernel. It's the only common atomic operation named __atomic*(), rather
than atomic_*(), and for consistency it would be better named
atomic_fetch_add_unless().
This lack of consistency is slightly confusing, and gets in the way of
scripting atomics. Given that, let's clean things up and promote it to
an official part of the atomics API, in the form of
atomic_fetch_add_unless().
This patch converts definitions and invocations over to the new name,
including the instrumented version, using the following script:
----
git grep -w __atomic_add_unless | while read line; do
sed -i '{s/\<__atomic_add_unless\>/atomic_fetch_add_unless/}' "${line%%:*}";
done
git grep -w __arch_atomic_add_unless | while read line; do
sed -i '{s/\<__arch_atomic_add_unless\>/arch_atomic_fetch_add_unless/}' "${line%%:*}";
done
----
Note that we do not have atomic{64,_long}_fetch_add_unless(), which will
be introduced by later patches.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Palmer Dabbelt <palmer@sifive.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20180621121321.4761-2-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Provide a command line and a sysfs knob to control SMT.
The command line options are:
'nosmt': Enumerate secondary threads, but do not online them
'nosmt=force': Ignore secondary threads completely during enumeration
via MP table and ACPI/MADT.
The sysfs control file has the following states (read/write):
'on': SMT is enabled. Secondary threads can be freely onlined
'off': SMT is disabled. Secondary threads, even if enumerated
cannot be onlined
'forceoff': SMT is permanentely disabled. Writes to the control
file are rejected.
'notsupported': SMT is not supported by the CPU
The command line option 'nosmt' sets the sysfs control to 'off'. This
can be changed to 'on' to reenable SMT during runtime.
The command line option 'nosmt=force' sets the sysfs control to
'forceoff'. This cannot be changed during runtime.
When SMT is 'on' and the control file is changed to 'off' then all online
secondary threads are offlined and attempts to online a secondary thread
later on are rejected.
When SMT is 'off' and the control file is changed to 'on' then secondary
threads can be onlined again. The 'off' -> 'on' transition does not
automatically online the secondary threads.
When the control file is set to 'forceoff', the behaviour is the same as
setting it to 'off', but the operation is irreversible and later writes to
the control file are rejected.
When the control status is 'notsupported' then writes to the control file
are rejected.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
