clang points out inconsistencies in the FIELD_PREP() invocation in
this driver that result from the 'mask' being a 32-bit value:

drivers/crypto/ccree/cc_driver.c:117:18: error: result of comparison of constant 18446744073709551615 with expression of type 'u32' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
        cache_params |= FIELD_PREP(mask, val);
                        ^~~~~~~~~~~~~~~~~~~~~
include/linux/bitfield.h:94:3: note: expanded from macro 'FIELD_PREP'
                __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: ");    \
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/bitfield.h:52:28: note: expanded from macro '__BF_FIELD_CHECK'
                BUILD_BUG_ON_MSG((_mask) > (typeof(_reg))~0ull,         \
                ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This does not happen in other places that just pass a constant here.

Work around the warnings by widening the type of the temporary variable.

Fixes: 05c2a705 ("crypto: ccree - rework cache parameters handling")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Gilad ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

As qm should register to uacce in UACCE_DEV_SVA mode,
this patch modifies to checks uacce mode before doing uacce
registration.
Signed-off-by: Kai Ye <yekai13@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

We need to export crypto_boot_test_finished in case api.c is
built-in while algapi.c is built as a module.

Fixes: adad556e ("crypto: api - Fix built-in testing dependency failures")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Stephen Rothwell <sfr@canb.auug.org.au> # ppc32 build
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

There is a spelling mistake in a literal string. Fix it.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

The ecc.c file started out as part of the ECDH algorithm but got
moved out into a standalone module later. It does not build without
CRYPTO_DEFAULT_RNG, so now that other modules are using it as well we
can run into this link error:

aarch64-linux-ld: ecc.c:(.text+0xfc8): undefined reference to `crypto_default_rng'
aarch64-linux-ld: ecc.c:(.text+0xff4): undefined reference to `crypto_put_default_rng'

Move the 'select CRYPTO_DEFAULT_RNG' statement into the correct symbol.

Fixes: 0d7a7864 ("crypto: ecrdsa - add EC-RDSA (GOST 34.10) algorithm")
Fixes: 4e660291 ("crypto: ecdsa - Add support for ECDSA signature verification")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

-ENOENT (ie. "there is no clock") is fine to ignore for an optional
clock, other values are not supposed to be ignored and should be
escalated to the caller (e.g. -EPROBE_DEFER). Ignore -ENOENT by using
devm_clk_get_optional().

While touching this code also add an error message for the fatal errors.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

When complex algorithms that depend on other algorithms are built
into the kernel, the order of registration must be done such that
the underlying algorithms are ready before the ones on top are
registered.  As otherwise they would fail during the self-test
which is required during registration.

In the past we have used subsystem initialisation ordering to
guarantee this.  The number of such precedence levels are limited
and they may cause ripple effects in other subsystems.

This patch solves this problem by delaying all self-tests during
boot-up for built-in algorithms.  They will be tested either when
something else in the kernel requests for them, or when we have
finished registering all built-in algorithms, whichever comes
earlier.
Reported-by: Vladis Dronov <vdronov@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

The MODULE_DEVICE_TABLE already creates proper alias for platform
driver.  Having another MODULE_ALIAS causes the alias to be duplicated.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

After reset or boot, QAT 4xxx devices are inactive and require to be
explicitly activated.
This is done by writing the DRV_ACTIVE bit in the PM_INTERRUPT register
and polling the PM_INIT_STATE to make sure that the transaction has
completed properly.

If this is not done, the driver will fail the initialization sequence
reporting the following message:
    [   22.081193] 4xxx 0000:f7:00.0: enabling device (0140 -> 0142)
    [   22.720285] QAT: AE0 is inactive!!
    [   22.720287] QAT: failed to get device out of reset
    [   22.720288] 4xxx 0000:f7:00.0: qat_hal_clr_reset error
    [   22.720290] 4xxx 0000:f7:00.0: Failed to init the AEs
    [   22.720290] 4xxx 0000:f7:00.0: Failed to initialise Acceleration Engine
    [   22.720789] 4xxx 0000:f7:00.0: Resetting device qat_dev0
    [   22.825099] 4xxx: probe of 0000:f7:00.0 failed with error -14

The patch also temporarily disables the power management source of
interrupt, to avoid possible spurious interrupts as the power management
feature is not fully supported.

The device init function has been added to adf_dev_init(), and not in the
probe of 4xxx to make sure that the device is re-enabled in case of
reset.

Note that the error code reported by hw_data->init_device() in
adf_dev_init() has been shadowed for consistency with the other calls
in the same function.

Fixes: 8c826816 ("crypto: qat - add qat_4xxx driver")
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Wojciech Ziemba <wojciech.ziemba@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

On newer CAAM versions, not all accelerators are disabled if the SoC is
a non-E variant. While the driver checks most of the modules for
availability, there is one - PKHA - which sticks out. On non-E variants
it is still reported as available, that is the number of instances is
non-zero, but it has limited functionality. In particular it doesn't
support encryption and decryption, but just signing and verifying. This
is indicated by a bit in the PKHA_MISC field. Take this bit into account
if we are checking for availability.

This will the following error:
[    8.167817] caam_jr 8020000.jr: 20000b0f: CCB: desc idx 11: : Invalid CHA selected.

Tested on an NXP LS1028A (non-E) SoC.

Fixes: d239b10d ("crypto: caam - add register map changes cf. Era 10")
Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

In the code for xts_crypt(), we check for the err value returned by
skcipher_walk_virt() and return from the function if it is non zero.
However, skcipher_walk_virt() can set walk.nbytes to 0, which would cause
us to call kernel_fpu_begin(), and then skip the kernel_fpu_end() call.

This patch checks for the walk.nbytes value instead, and returns if
walk.nbytes is 0. This prevents us from calling kernel_fpu_begin() in
the first place and also covers the case of having a non zero err value
returned from skcipher_walk_virt().
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Shreyansh Chouhan <chouhan.shreyansh630@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Coverity warns uf an unused value:

CID 44865 (#2 of 2): Unused value (UNUSED_VALUE)
assigned_value: Assigning value -14 to ret here, but that stored value is
overwritten before it can be used.
2006        int ret = -EFAULT;
...
value_overwrite: Overwriting previous write to ret with value from drbg_seed(drbg, &addtl, false).
2052        ret = drbg_seed(drbg, &addtl, false);

Fix this by removing the variable initializer.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

The assignment to error return variable ret and then the jump to
an error exit path can be simplified by just returning the error
return at the failure point. This allows variable ret and the
error return path to be removed. This cleans up a static analysis
warninng that variable ret is being assigned (value never being
used) and being re-assigned later.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Use the devm_platform_ioremap_resource() helper instead of
calling platform_get_resource() and devm_ioremap_resource()
separately
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Remove packed attribute from structures that do not need to be packed.
These are just used internally and not shared with firmware.

This also fixes a series of warning when compiling the driver with the
flag -Waddress-of-packed-member, similar to the following:

    drivers/crypto/qat/qat_c62xvf/adf_c62xvf_hw_data.c:102:28: warning: taking address of packed member 'csr_ops' of class or structure 'adf_hw_device_data' may result in an unaligned pointer value
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Wojciech Ziemba <wojciech.ziemba@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

If devm_request_irq() fails inside adf_request_irqs(), unwind properly by
freeing the allocated irqs.
Signed-off-by: Wojciech Ziemba <wojciech.ziemba@intel.com>
Co-developed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Change the irq allocation logic so that it is possible to free only the
allocated irqs in case of error.
A new flag is introduced for every PF/VF interrupt. This flag is set to
"true" only when the interrupt is requested.
During clean up, devm_free_irq() is only called if this flag is set.
Signed-off-by: Maksim Lukoshkov <maksim.lukoshkov@intel.com>
Co-developed-by: Wojciech Ziemba <wojciech.ziemba@intel.com>
Signed-off-by: Wojciech Ziemba <wojciech.ziemba@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

This patch removes redundant CPU affinity to AE cluster IRQ.
Signed-off-by: Wojciech Ziemba <wojciech.ziemba@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Replace deprecated MSI enable and disable respectively and update
handling of return values.
Signed-off-by: Wojciech Ziemba <wojciech.ziemba@intel.com>
Co-developed-by: Gupta Shashank <shashank.gupta@intel.com>
Signed-off-by: Gupta Shashank <shashank.gupta@intel.com>
Reviewed-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Allocate an extra memory page for qp in the qp memory initialization.
Set a qp error flag in the extra page addr when device resetting.
This error flag can be seen in the userspace. This flag can helps
users to stop tasks when device resetting. After resetting, this error
flag will be reset when this qp is created again. So app should release
the old qp and request a new one, and do the task on the new queue
again.
Signed-off-by: Kai Ye <yekai13@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Allocate an extra memory page for qp. This extra page is
used to set the device or qp status. But this page not
be used currently. Meanwhile it leads to dus size not equal
to mmap size as using uacce sva mode, and cause the app task
broken.
Signed-off-by: Kai Ye <yekai13@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

The function qm_qos_value_init expects an unsigned integer but
is incorrectly supplying a signed format to sscanf.  This patch
fixes it.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

With the SIMD code path removed, we can clean up the CCM auth-only path
a bit further, by passing the 'macp' input buffer pointer by value,
rather than by reference, and taking the output value from the
function's return value.

This way, the compiler is no longer forced to allocate macp on the
stack. This is not expected to make any difference in practice, it just
makes for slightly cleaner code.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

AES-CCM (as used in WPA2 CCMP, for instance) typically involves
authenticate-only data, and operates on a single network packet, and so
the common case is for the authenticate, en/decrypt and finalize SIMD
helpers to all be called exactly once in sequence. Since
kernel_neon_end() now involves manipulation of the preemption state as
well as the softirq mask state, let's reduce the number of times we are
forced to call it to only once if we are handling this common case.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

AES/CCM on arm64 is implemented as a synchronous AEAD, and so it is
guaranteed by the API that it is only invoked in task or softirq
context. Since softirqs are now only handled when the SIMD is not
being used in the task context that was interrupted to service the
softirq, we no longer need a fallback path. Let's remove it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

In SIMD accelerated crypto drivers, we typically yield the SIMD unit
after processing 4 KiB of input, to avoid scheduling blackouts caused by
the fact that claiming the SIMD unit disables preemption as well as
softirq processing.

The arm64 CCM driver does this implicitly for the ciphertext, due to the
fact that the skcipher API never processes more than a single page at a
time. However, the scatterwalk performed by this driver when processing
the authenticate-only data will keep the SIMD unit occupied until it
completes.

So cap the scatterwalk steps to 4 KiB.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Calls into the skcipher API can only occur from contexts where the SIMD
unit is available, so there is no need for the SIMD helper.
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Calls into the skcipher API can only occur from contexts where the SIMD
unit is available, so there is no need for the SIMD helper.
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Now that kernel mode SIMD is guaranteed to be available when executing
in task or softirq context, we no longer need scalar fallbacks to use
when the NEON is unavailable. So get rid of them.
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

When building with clang and GNU as, there is a warning about ignored
changed section attributes:

/tmp/sm4-c916c8.s: Assembler messages:
/tmp/sm4-c916c8.s:677: Warning: ignoring changed section attributes for
.data..cacheline_aligned

"static const" places the data in .rodata but __cacheline_aligned has
the section attribute to place it in .data..cacheline_aligned, in
addition to the aligned attribute.

To keep the alignment but avoid attempting to change sections, use the
____cacheline_aligned attribute, which is just the aligned attribute.

Fixes: 2b31277a ("crypto: sm4 - create SM4 library based on sm4 generic code")
Link: https://github.com/ClangBuiltLinux/linux/issues/1441Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

it's helpful to do a complie test in other platform(e.g.X86)
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Drop "begin kernel-doc (/**)" entries in jitterentropy.c
since they are not in kernel-doc format and they cause
many complaints (warnings) from scripts/kernel-doc.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Stephan Mueller <smueller@chronox.de>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-crypto@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Merge tag 'perf-tools-for-v5.15-2021-09-11' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull more perf tools updates from Arnaldo Carvalho de Melo:

 - Add missing fields and remove some duplicate fields when printing a
   perf_event_attr.

 - Fix hybrid config terms list corruption.

 - Update kernel header copies, some resulted in new kernel features
   being automagically added to 'perf trace' syscall/tracepoint argument
   id->string translators.

 - Add a file generated during the documentation build to .gitignore.

 - Add an option to build without libbfd, as some distros, like Debian
   consider its ABI unstable.

 - Add support to print a textual representation of IBS raw sample data
   in 'perf report'.

 - Fix bpf 'perf test' sample mismatch reporting

 - Fix passing arguments to stackcollapse report in a 'perf script'
   python script.

 - Allow build-id with trailing zeros.

 - Look for ImageBase in PE file to compute .text offset.

* tag 'perf-tools-for-v5.15-2021-09-11' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (25 commits)
  tools headers UAPI: Update tools's copy of drm.h headers
  tools headers UAPI: Sync drm/i915_drm.h with the kernel sources
  tools headers UAPI: Sync linux/fs.h with the kernel sources
  tools headers UAPI: Sync linux/in.h copy with the kernel sources
  perf tools: Add an option to build without libbfd
  perf tools: Allow build-id with trailing zeros
  perf tools: Fix hybrid config terms list corruption
  perf tools: Factor out copy_config_terms() and free_config_terms()
  perf tools: Fix perf_event_attr__fprintf() missing/dupl. fields
  perf tools: Ignore Documentation dependency file
  perf bpf: Provide a weak btf__load_from_kernel_by_id() for older libbpf versions
  tools include UAPI: Update linux/mount.h copy
  perf beauty: Cover more flags in the  move_mount syscall argument beautifier
  tools headers UAPI: Sync linux/prctl.h with the kernel sources
  tools include UAPI: Sync sound/asound.h copy with the kernel sources
  tools headers UAPI: Sync linux/kvm.h with the kernel sources
  tools headers UAPI: Sync x86's asm/kvm.h with the kernel sources
  perf report: Add support to print a textual representation of IBS raw sample data
  perf report: Add tools/arch/x86/include/asm/amd-ibs.h
  perf env: Add perf_env__cpuid, perf_env__{nr_}pmu_mappings
  ...

Pull compiler attributes updates from Miguel Ojeda:

 - Fix __has_attribute(__no_sanitize_coverage__) for GCC 4 (Marco Elver)

 - Add Nick as Reviewer for compiler_attributes.h (Nick Desaulniers)

 - Move __compiletime_{error|warning} (Nick Desaulniers)

* tag 'compiler-attributes-for-linus-v5.15-rc1-v2' of git://github.com/ojeda/linux:
  compiler_attributes.h: move __compiletime_{error|warning}
  MAINTAINERS: add Nick as Reviewer for compiler_attributes.h
  Compiler Attributes: fix __has_attribute(__no_sanitize_coverage__) for GCC 4

Pull auxdisplay updates from Miguel Ojeda:
 "An assortment of improvements for auxdisplay:

   - Replace symbolic permissions with octal permissions (Jinchao Wang)

   - ks0108: Switch to use module_parport_driver() (Andy Shevchenko)

   - charlcd: Drop unneeded initializers and switch to C99 style (Andy
     Shevchenko)

   - hd44780: Fix oops on module unloading (Lars Poeschel)

   - Add I2C gpio expander example (Ralf Schlatterbeck)"

* tag 'auxdisplay-for-linus-v5.15-rc1' of git://github.com/ojeda/linux:
  auxdisplay: Replace symbolic permissions with octal permissions
  auxdisplay: ks0108: Switch to use module_parport_driver()
  auxdisplay: charlcd: Drop unneeded initializers and switch to C99 style
  auxdisplay: hd44780: Fix oops on module unloading
  auxdisplay: Add I2C gpio expander example

Pull CPU hotplug updates from Thomas Gleixner:
 "Updates for the SMP and CPU hotplug:

   - Remove DEFINE_SMP_CALL_CACHE_FUNCTION() which is a left over of the
     original hotplug code and now causing trouble with the ARM64 cache
     topology setup due to the pointless SMP function call.

     It's not longer required as the hotplug callbacks are guaranteed to
     be invoked on the upcoming CPU.

   - Remove the deprecated and now unused CPU hotplug functions

   - Rewrite the CPU hotplug API documentation"

* tag 'smp-urgent-2021-09-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Documentation: core-api/cpuhotplug: Rewrite the API section
  cpu/hotplug: Remove deprecated CPU-hotplug functions.
  thermal: Replace deprecated CPU-hotplug functions.
  drivers: base: cacheinfo: Get rid of DEFINE_SMP_CALL_CACHE_FUNCTION()

Merge tag 'char-misc-5.15-rc1-lkdtm' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull misc driver fix from Greg KH:
 "Here is a single patch for 5.15-rc1, for the lkdtm misc driver.

  It resolves a build issue that many people were hitting with your
  current tree, and Kees and others felt would be good to get merged
  before -rc1 comes out, to prevent them from having to constantly hit
  it as many development trees restart on -rc1, not older -rc releases.

  It has NOT been in linux-next, but has passed 0-day testing and looks
  'obviously correct' when reviewing it locally :)"

* tag 'char-misc-5.15-rc1-lkdtm' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  lkdtm: Use init_uts_ns.name instead of macros

Pull IPMI updates from Corey Minyard:
 "A couple of very minor fixes for style and rate limiting.

  Nothing big, but probably needs to go in"

* tag 'for-linus-5.15-1' of git://github.com/cminyard/linux-ipmi:
  char: ipmi: use DEVICE_ATTR helper macro
  ipmi: rate limit ipmi smi_event failure message

Pull scheduler fixes from Borislav Petkov:

 - Make sure the idle timer expires in hardirq context, on PREEMPT_RT

 - Make sure the run-queue balance callback is invoked only on the
   outgoing CPU

* tag 'sched_urgent_for_v5.15_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched: Prevent balance_push() on remote runqueues
  sched/idle: Make the idle timer expire in hard interrupt context