Contrary to the comments, those do *NOT* verify anything about
writability of memory, etc.
In all cases addresses are passed only to copy_to_user().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Address is passed to get_user_pages_fast(), which does access_ok().
NB: this is called only from ->ioctl(), and only under USER_DS.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Fix several issues in the previous gfs2_find_jhead fix:
* When updating @blocks_submitted, @block refers to the first block block not
submitted yet, not the last block submitted, so fix an off-by-one error.
* We want to ensure that @blocks_submitted is far enough ahead of @blocks_read
to guarantee that there is in-flight I/O. Otherwise, we'll eventually end up
waiting for pages that haven't been submitted, yet.
* It's much easier to compare the number of blocks added with the number of
blocks submitted to limit the maximum bio size.
* Even with bio chaining, we can keep adding blocks until we reach the maximum
bio size, as long as we stop at a page boundary. This simplifies the logic.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
In general each DMA-based SPI transfer can be split up into two stages:
DMA data transmission/reception and SPI-bus transmission/reception. DMA
asynchronous transactions completion can be tracked by means of the
DMA async Tx-descriptor completion callback. But that callback being
called indicates that the DMA transfer has been finished, it doesn't
mean that SPI data transmission is also done. Moreover in fact it isn't
for at least Tx-only SPI transfers. Upon DMA transfer completion some
data is left in the Tx FIFO and being pushed out by the SPI controller.
So in order to make sure that an SPI transfer is completely pushed to the
SPI-bus, the driver has to wait for both DMA transaction and the SPI-bus
transmission/reception are finished. Note if there is a way to
asynchronously track the former event by means of the DMA async Tx
callback, there isn't easy one for the later (IRQ-based solution won't
work since SPI controller doesn't notify about Rx FIFO being empty).
The DMA transfer completion callback isn't suitable to wait for the
SPI controller activity finish either. The callback might (in case of DW
DMAC it will) be called in the tasklet context. Waiting for the SPI
controller to complete the transfer might take a considerable amount of
time since SPI-bus might be pretty slow. In this case delaying the
execution in the tasklet atomic context might cause significant system
performance drop.
So to speak the best option we've got to solve the problem is to
consequently wait for both stages being finished in the locally
implemented SPI transfer execution procedure even if it costs us of the
local wait-function re-implementation. In this case we don't need to use
the SPI-core transfer-wait functionality, but we'll make sure that
all DMA and SPI-bus transactions are completely finished before the
SPI-core transfer_one callback returns. In this commit we provide an
implementation of the DMA-transfers completion wait functionality.
The DW APB SSI DMA-specific SPI transfer_one function waits for both
Tx and Rx DMA transfers being finished, and only then exits with zero
returned signalling to the SPI core that the SPI transfer is finished.
This implementation is fully equivalent to the currently used
DMA-execution-SPI-core-wait algorithm. The SPI-bus transmission/reception
wait methods will be added in the follow-up commits.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
Link: https://lore.kernel.org/r/20200529131205.31838-4-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>
Pull devfreq updates for v5.8 from Chanwoo Choi:
"1. Update devfreq core
- Use lockdep function for checking mutex state instead of manual checking.
- Replace strncpy with strscpy to fix the compile warning.
2. Update devfreq driver
- Add new imx-bus.c devfreq driver for controlling the bus frequenncy
and it registers the imx interconnect device which indicates the imx-bus.c
as the parent device. This relation make the connection between imx-bus.c
and imx interconnect nodes. In result, the imx-bus.c devfreq driver handles
the DEV_PM_QOS_MIN_FREQUENCY requirements from imx interconnect nodes
in order to support the minimum bus bandwidth of interconnect nodes.
- Delete unneed error message and update the boosting on tegra30-devfreq.c."
* tag 'devfreq-next-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/chanwoo/linux:
PM / devfreq: Use lockdep asserts instead of manual checks for locked mutex
PM / devfreq: imx-bus: Fix inconsistent IS_ERR and PTR_ERR
PM / devfreq: Replace strncpy with strscpy
PM / devfreq: imx: Register interconnect device
PM / devfreq: Add generic imx bus scaling driver
PM / devfreq: tegra30: Delete an error message in tegra_devfreq_probe()
PM / devfreq: tegra30: Make CPUFreq notifier to take into account boosting
This function acts as an out-of-line helper for is_local_mountpoint
is only called after the latter verifies the dentry is not a mountpoint.
There's no semantic changes and the resulting object code is smaller:
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-26 (-26)
Function old new delta
__is_local_mountpoint 147 121 -26
Total: Before=34161, After=34135, chg -0.08%
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This is no point to unlock() and then lock() the same mutex
back to back.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
008847f66c ("workqueue: allow rescuer thread to do more work.") made
the rescuer worker requeue the pwq immediately if there may be more
work items which need rescuing instead of waiting for the next mayday
timer expiration. Unfortunately, it checks only whether the pool needs
help from rescuers, but it doesn't check whether the pwq has work items
in the pool (the real reason that this rescuer can help for the pool).
The patch adds the check and void unneeded requeuing.
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Just take copy_from_user() out of do_insn_ioctl() into the caller and
have compat_insn() build a native version and pass it to do_insn_ioctl()
directly.
One difference from the previous commits is that the helper used to
convert 32bit variant to native has two users - compat_insn() and
compat_insnlist(). The latter will be converted in next commit;
for now we simply split the helper in two variants - "userland 32bit
to kernel native" and "userland 32bit to userland native". The latter
is renamed old get_compat_insn(); it will be gone in the next commit.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Warm reboot can not reset controller qca6390 due to
lack of controllable power supply, so causes firmware
download failure during enable.
Fixed by sending VSC EDL_SOC_RESET to reset qca6390
within added device shutdown implementation.
Signed-off-by: Zijun Hu <zijuhu@codeaurora.org>
Tested-by: Zijun Hu <zijuhu@codeaurora.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The workqueue code has it's internal spinlocks (pool::lock), which
are acquired on most workqueue operations. These spinlocks are
converted to 'sleeping' spinlocks on a RT-kernel.
Workqueue functions can be invoked from contexts which are truly atomic
even on a PREEMPT_RT enabled kernel. Taking sleeping locks from such
contexts is forbidden.
The pool::lock hold times are bound and the code sections are
relatively short, which allows to convert pool::lock and as a
consequence wq_mayday_lock to raw spinlocks which are truly spinning
locks even on a PREEMPT_RT kernel.
With the previous conversion of the manager waitqueue to a simple
waitqueue workqueues are now fully RT compliant.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Lai Jiangshan <jiangshanlai@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The workqueue code has it's internal spinlock (pool::lock) and also
implicit spinlock usage in the wq_manager waitqueue. These spinlocks
are converted to 'sleeping' spinlocks on a RT-kernel.
Workqueue functions can be invoked from contexts which are truly atomic
even on a PREEMPT_RT enabled kernel. Taking sleeping locks from such
contexts is forbidden.
pool::lock can be converted to a raw spinlock as the lock held times
are short. But the workqueue manager waitqueue is handled inside of
pool::lock held regions which again violates the lock nesting rules
of raw and regular spinlocks.
The manager waitqueue has no special requirements like custom wakeup
callbacks or mass wakeups. While it does not use exclusive wait mode
explicitly there is no strict requirement to queue the waiters in a
particular order as there is only one waiter at a time.
This allows to replace the waitqueue with rcuwait which solves the
locking problem because rcuwait relies on existing locking.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
The Debian kernel v5.6 triggers this kernel panic:
Kernel panic - not syncing: Bad Address (null pointer deref?)
Bad Address (null pointer deref?): Code=26 (Data memory access rights trap) at addr 0000000000000000
CPU: 0 PID: 0 Comm: swapper Not tainted 5.6.0-2-parisc64 #1 Debian 5.6.14-1
IAOQ[0]: mem_init+0xb0/0x150
IAOQ[1]: mem_init+0xb4/0x150
RP(r2): start_kernel+0x6c8/0x1190
Backtrace:
[<0000000040101ab4>] start_kernel+0x6c8/0x1190
[<0000000040108574>] start_parisc+0x158/0x1b8
on a HP-PARISC rp3440 machine with this memory layout:
Memory Ranges:
0) Start 0x0000000000000000 End 0x000000003fffffff Size 1024 MB
1) Start 0x0000004040000000 End 0x00000040ffdfffff Size 3070 MB
Fix the crash by avoiding virt_to_page() and similar functions in
mem_init() until the memory zones have been fully set up.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v5.0+
Hi!
This patchset is another attempt to fix the regulator coupling on
Exynos5800/5422 SoCs. Here are links to the previous attempts:
https://lore.kernel.org/linux-samsung-soc/20191008101709.qVNy8eijBi0LynOteWFMnTg4GUwKG599n6OyYoX1Abs@z/https://lore.kernel.org/lkml/20191017102758.8104-1-m.szyprowski@samsung.com/https://lore.kernel.org/linux-pm/cover.1589528491.git.viresh.kumar@linaro.org/https://lore.kernel.org/linux-pm/20200528131130.17984-1-m.szyprowski@samsung.com/
The problem is with "vdd_int" regulator coupled with "vdd_arm" on Odroid
XU3/XU4 boards family. "vdd_arm" is handled by CPUfreq. "vdd_int" is
handled by devfreq. CPUfreq initialized quite early during boot and it
starts changing OPPs and "vdd_arm" value. Sometimes CPU activity during
boot goes down and some low-frequency OPPs are selected, what in turn
causes lowering "vdd_arm". This happens before devfreq applies its
requirements on "vdd_int". Regulator balancing code reduces "vdd_arm"
voltage value, what in turn causes lowering "vdd_int" value to the lowest
possible value. This is much below the operation point of the wcore bus,
which still runs at the highest frequency.
The issue was hard to notice because in the most cases the board managed
to boot properly, even when the regulator was set to lowest value allowed
by the regulator constraints. However, it caused some random issues,
which can be observed as "Unhandled prefetch abort" or low USB stability.
Adding more and more special cases to the generic code has been rejected,
so the only way to ensure the desired behavior on Exynos5800-based SoCs
is to make a custom regulator coupler driver.
Best regards,
Marek Szyprowski
Patch summary:
Marek Szyprowski (2):
regulator: extract voltage balancing code to separate function
soc: samsung: Add simple voltage coupler for Exynos5800
arch/arm/mach-exynos/Kconfig | 1 +
drivers/regulator/core.c | 49 ++++++++-------
drivers/soc/samsung/Kconfig | 3 +
drivers/soc/samsung/Makefile | 1 +
.../soc/samsung/exynos-regulator-coupler.c | 59 +++++++++++++++++++
include/linux/regulator/coupler.h | 8 +++
6 files changed, 101 insertions(+), 20 deletions(-)
create mode 100644 drivers/soc/samsung/exynos-regulator-coupler.c
--
2.17.1
base-commit: 8f3d9f3542
Recent changes result in multiple dmesg traces such as:
[ 14.410435] Audio Port: ASoC: error at snd_soc_link_startup on Audio
Port: 1
[ 14.410446] sst-mfld-platform sst-mfld-platform: ASoC: error at
snd_soc_dai_startup on media-cpu-dai: 1
These messages are not really errors, when dai and dai-link callbacks
return the value of e.g. snd_pcm_hw_constraint_single() the result is
"Positive if the value is changed, zero if it's not changed, or a
negative error code"
Add a simple test to skip the checks for positive returned values
Suggested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200529123613.13447-1-pierre-louis.bossart@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Sub-devices of a real DMA device might exist on a separate segment than
the real DMA device and its IOMMU. These devices should still have a
valid device_domain_info, but the current dma alias model won't
allocate info for the subdevice.
This patch adds a segment member to struct device_domain_info and uses
the sub-device's BDF so that these sub-devices won't alias to other
devices.
Fixes: 2b0140c696 ("iommu/vt-d: Use pci_real_dma_dev() for mapping")
Cc: stable@vger.kernel.org # v5.6+
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200527165617.297470-3-jonathan.derrick@intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Domain context mapping can encounter issues with sub-devices of a real
DMA device. A sub-device cannot have a valid context entry due to it
potentially aliasing another device's 16-bit ID. It's expected that
sub-devices of the real DMA device uses the real DMA device's requester
when context mapping.
This is an issue when a sub-device is removed where the context entry is
cleared for all aliases. Other sub-devices are still valid, resulting in
those sub-devices being stranded without valid context entries.
The correct approach is to use the real DMA device when programming the
context entries. The insertion path is correct because device_to_iommu()
will return the bus and devfn of the real DMA device. The removal path
needs to only operate on the real DMA device, otherwise the entire
context entry would be cleared for all sub-devices of the real DMA
device.
This patch also adds a helper to determine if a struct device is a
sub-device of a real DMA device.
Fixes: 2b0140c696 ("iommu/vt-d: Use pci_real_dma_dev() for mapping")
Cc: stable@vger.kernel.org # v5.6+
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20200527165617.297470-2-jonathan.derrick@intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
