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This potentially simplifies low-level PWM drivers.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core
Pull irqchip updates from Marc Zyngier:
- Revamped the irqdomain internals to consistently cache irqdata
- Expose a new API to simplify IRQ handling involving an irqdomain by
not using the IRQ number
- Convert all the irqchip drivers to this new API
- Allow the Qualcomm PDC driver to be compiled as a module
- Fix HiSi MBIGEN compile warning when CONFIG_ACPI isn't selected
- Remove a bunch of spurious printks on error paths
- The obligatory couple of DT updates
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This reverts commits 4bad58ebc8bc4f20d89cff95417c9b4674769709 (and
399f8dd9a866e107639eabd3c1979cd526ca3a98, which tried to fix it).
I do not believe these are correct, and I'm about to release 5.13, so am
reverting them out of an abundance of caution.
The locking is odd, and appears broken.
On the allocation side (in __sigqueue_alloc()), the locking is somewhat
straightforward: it depends on sighand->siglock. Since one caller
doesn't hold that lock, it further then tests 'sigqueue_flags' to avoid
the case with no locks held.
On the freeing side (in sigqueue_cache_or_free()), there is no locking
at all, and the logic instead depends on 'current' being a single
thread, and not able to race with itself.
To make things more exciting, there's also the data race between freeing
a signal and allocating one, which is handled by using WRITE_ONCE() and
READ_ONCE(), and being mutually exclusive wrt the initial state (ie
freeing will only free if the old state was NULL, while allocating will
obviously only use the value if it was non-NULL, so only one or the
other will actually act on the value).
However, while the free->alloc paths do seem mutually exclusive thanks
to just the data value dependency, it's not clear what the memory
ordering constraints are on it. Could writes from the previous
allocation possibly be delayed and seen by the new allocation later,
causing logical inconsistencies?
So it's all very exciting and unusual.
And in particular, it seems that the freeing side is incorrect in
depending on "current" being single-threaded. Yes, 'current' is a
single thread, but in the presense of asynchronous events even a single
thread can have data races.
And such asynchronous events can and do happen, with interrupts causing
signals to be flushed and thus free'd (for example - sending a
SIGCONT/SIGSTOP can happen from interrupt context, and can flush
previously queued process control signals).
So regardless of all the other questions about the memory ordering and
locking for this new cached allocation, the sigqueue_cache_or_free()
assumptions seem to be fundamentally incorrect.
It may be that people will show me the errors of my ways, and tell me
why this is all safe after all. We can reinstate it if so. But my
current belief is that the WRITE_ONCE() that sets the cached entry needs
to be a smp_store_release(), and the READ_ONCE() that finds a cached
entry needs to be a smp_load_acquire() to handle memory ordering
correctly.
And the sequence in sigqueue_cache_or_free() would need to either use a
lock or at least be interrupt-safe some way (perhaps by using something
like the percpu 'cmpxchg': it doesn't need to be SMP-safe, but like the
percpu operations it needs to be interrupt-safe).
Fixes: 399f8dd9a866 ("signal: Prevent sigqueue caching after task got released")
Fixes: 4bad58ebc8bc ("signal: Allow tasks to cache one sigqueue struct")
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Current client use 'struct cmdq_pkt' as callback data, so
change 'void *data' to 'struct cmdq_pkt *pkt'. Keep data
until client use pkt instead of data.
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Reviewed-by: Yongqiang Niu <yongqiang.niu@mediatek.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
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cmdq_cb_status is an error status. Use the standard error number
instead of cmdq_cb_status to prevent status duplication.
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Reviewed-by: Yongqiang Niu <yongqiang.niu@mediatek.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
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Add SW steering support for sFlow / flow sampler action.
Signed-off-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
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In the context of high-performance computing (HPC), the Operating System
Noise (*osnoise*) refers to the interference experienced by an application
due to activities inside the operating system. In the context of Linux,
NMIs, IRQs, SoftIRQs, and any other system thread can cause noise to the
system. Moreover, hardware-related jobs can also cause noise, for example,
via SMIs.
The osnoise tracer leverages the hwlat_detector by running a similar
loop with preemption, SoftIRQs and IRQs enabled, thus allowing all
the sources of *osnoise* during its execution. Using the same approach
of hwlat, osnoise takes note of the entry and exit point of any
source of interferences, increasing a per-cpu interference counter. The
osnoise tracer also saves an interference counter for each source of
interference. The interference counter for NMI, IRQs, SoftIRQs, and
threads is increased anytime the tool observes these interferences' entry
events. When a noise happens without any interference from the operating
system level, the hardware noise counter increases, pointing to a
hardware-related noise. In this way, osnoise can account for any
source of interference. At the end of the period, the osnoise tracer
prints the sum of all noise, the max single noise, the percentage of CPU
available for the thread, and the counters for the noise sources.
Usage
Write the ASCII text "osnoise" into the current_tracer file of the
tracing system (generally mounted at /sys/kernel/tracing).
For example::
[root@f32 ~]# cd /sys/kernel/tracing/
[root@f32 tracing]# echo osnoise > current_tracer
It is possible to follow the trace by reading the trace trace file::
[root@f32 tracing]# cat trace
# tracer: osnoise
#
# _-----=> irqs-off
# / _----=> need-resched
# | / _---=> hardirq/softirq
# || / _--=> preempt-depth MAX
# || / SINGLE Interference counters:
# |||| RUNTIME NOISE % OF CPU NOISE +-----------------------------+
# TASK-PID CPU# |||| TIMESTAMP IN US IN US AVAILABLE IN US HW NMI IRQ SIRQ THREAD
# | | | |||| | | | | | | | | | |
<...>-859 [000] .... 81.637220: 1000000 190 99.98100 9 18 0 1007 18 1
<...>-860 [001] .... 81.638154: 1000000 656 99.93440 74 23 0 1006 16 3
<...>-861 [002] .... 81.638193: 1000000 5675 99.43250 202 6 0 1013 25 21
<...>-862 [003] .... 81.638242: 1000000 125 99.98750 45 1 0 1011 23 0
<...>-863 [004] .... 81.638260: 1000000 1721 99.82790 168 7 0 1002 49 41
<...>-864 [005] .... 81.638286: 1000000 263 99.97370 57 6 0 1006 26 2
<...>-865 [006] .... 81.638302: 1000000 109 99.98910 21 3 0 1006 18 1
<...>-866 [007] .... 81.638326: 1000000 7816 99.21840 107 8 0 1016 39 19
In addition to the regular trace fields (from TASK-PID to TIMESTAMP), the
tracer prints a message at the end of each period for each CPU that is
running an osnoise/CPU thread. The osnoise specific fields report:
- The RUNTIME IN USE reports the amount of time in microseconds that
the osnoise thread kept looping reading the time.
- The NOISE IN US reports the sum of noise in microseconds observed
by the osnoise tracer during the associated runtime.
- The % OF CPU AVAILABLE reports the percentage of CPU available for
the osnoise thread during the runtime window.
- The MAX SINGLE NOISE IN US reports the maximum single noise observed
during the runtime window.
- The Interference counters display how many each of the respective
interference happened during the runtime window.
Note that the example above shows a high number of HW noise samples.
The reason being is that this sample was taken on a virtual machine,
and the host interference is detected as a hardware interference.
Tracer options
The tracer has a set of options inside the osnoise directory, they are:
- osnoise/cpus: CPUs at which a osnoise thread will execute.
- osnoise/period_us: the period of the osnoise thread.
- osnoise/runtime_us: how long an osnoise thread will look for noise.
- osnoise/stop_tracing_us: stop the system tracing if a single noise
higher than the configured value happens. Writing 0 disables this
option.
- osnoise/stop_tracing_total_us: stop the system tracing if total noise
higher than the configured value happens. Writing 0 disables this
option.
- tracing_threshold: the minimum delta between two time() reads to be
considered as noise, in us. When set to 0, the default value will
be used, which is currently 5 us.
Additional Tracing
In addition to the tracer, a set of tracepoints were added to
facilitate the identification of the osnoise source.
- osnoise:sample_threshold: printed anytime a noise is higher than
the configurable tolerance_ns.
- osnoise:nmi_noise: noise from NMI, including the duration.
- osnoise:irq_noise: noise from an IRQ, including the duration.
- osnoise:softirq_noise: noise from a SoftIRQ, including the
duration.
- osnoise:thread_noise: noise from a thread, including the duration.
Note that all the values are *net values*. For example, if while osnoise
is running, another thread preempts the osnoise thread, it will start a
thread_noise duration at the start. Then, an IRQ takes place, preempting
the thread_noise, starting a irq_noise. When the IRQ ends its execution,
it will compute its duration, and this duration will be subtracted from
the thread_noise, in such a way as to avoid the double accounting of the
IRQ execution. This logic is valid for all sources of noise.
Here is one example of the usage of these tracepoints::
osnoise/8-961 [008] d.h. 5789.857532: irq_noise: local_timer:236 start 5789.857529929 duration 1845 ns
osnoise/8-961 [008] dNh. 5789.858408: irq_noise: local_timer:236 start 5789.858404871 duration 2848 ns
migration/8-54 [008] d... 5789.858413: thread_noise: migration/8:54 start 5789.858409300 duration 3068 ns
osnoise/8-961 [008] .... 5789.858413: sample_threshold: start 5789.858404555 duration 8723 ns interferences 2
In this example, a noise sample of 8 microseconds was reported in the last
line, pointing to two interferences. Looking backward in the trace, the
two previous entries were about the migration thread running after a
timer IRQ execution. The first event is not part of the noise because
it took place one millisecond before.
It is worth noticing that the sum of the duration reported in the
tracepoints is smaller than eight us reported in the sample_threshold.
The reason roots in the overhead of the entry and exit code that happens
before and after any interference execution. This justifies the dual
approach: measuring thread and tracing.
Link: https://lkml.kernel.org/r/e649467042d60e7b62714c9c6751a56299d15119.1624372313.git.bristot@redhat.com
Cc: Phil Auld <pauld@redhat.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Kate Carcia <kcarcia@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexandre Chartre <alexandre.chartre@oracle.com>
Cc: Clark Willaims <williams@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@redhat.com>
[
Made the following functions static:
trace_irqentry_callback()
trace_irqexit_callback()
trace_intel_irqentry_callback()
trace_intel_irqexit_callback()
Added to include/trace.h:
osnoise_arch_register()
osnoise_arch_unregister()
Fixed define logic for LATENCY_FS_NOTIFY
Reported-by: kernel test robot <lkp@intel.com>
]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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The newly implemented fwnode_mdbiobus_register turned out to be
problematic - in case the fwnode_/of_/acpi_mdio are built as
modules, a dependency cycle can be observed during the depmod phase of
modules_install, eg.:
depmod: ERROR: Cycle detected: fwnode_mdio -> of_mdio -> fwnode_mdio
depmod: ERROR: Found 2 modules in dependency cycles!
OR:
depmod: ERROR: Cycle detected: acpi_mdio -> fwnode_mdio -> acpi_mdio
depmod: ERROR: Found 2 modules in dependency cycles!
A possible solution could be to rework fwnode_mdiobus_register,
so that to merge the contents of acpi_mdiobus_register and
of_mdiobus_register. However feasible, such change would
be very intrusive and affect huge amount of the of_mdiobus_register
users.
Since there are currently 2 users of ACPI and MDIO
(xgmac_mdio and mvmdio), withdraw the fwnode_mdbiobus_register
and roll back to a simple 'if' condition in affected drivers.
Fixes: 62a6ef6a996f ("net: mdiobus: Introduce fwnode_mdbiobus_register()")
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Merge misc fixes from Andrew Morton:
"24 patches, based on 4a09d388f2ab382f217a764e6a152b3f614246f6.
Subsystems affected by this patch series: mm (thp, vmalloc, hugetlb,
memory-failure, and pagealloc), nilfs2, kthread, MAINTAINERS, and
mailmap"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (24 commits)
mailmap: add Marek's other e-mail address and identity without diacritics
MAINTAINERS: fix Marek's identity again
mm/page_alloc: do bulk array bounds check after checking populated elements
mm/page_alloc: __alloc_pages_bulk(): do bounds check before accessing array
mm/hwpoison: do not lock page again when me_huge_page() successfully recovers
mm,hwpoison: return -EHWPOISON to denote that the page has already been poisoned
mm/memory-failure: use a mutex to avoid memory_failure() races
mm, futex: fix shared futex pgoff on shmem huge page
kthread: prevent deadlock when kthread_mod_delayed_work() races with kthread_cancel_delayed_work_sync()
kthread_worker: split code for canceling the delayed work timer
mm/vmalloc: unbreak kasan vmalloc support
KVM: s390: prepare for hugepage vmalloc
mm/vmalloc: add vmalloc_no_huge
nilfs2: fix memory leak in nilfs_sysfs_delete_device_group
mm/thp: another PVMW_SYNC fix in page_vma_mapped_walk()
mm/thp: fix page_vma_mapped_walk() if THP mapped by ptes
mm: page_vma_mapped_walk(): get vma_address_end() earlier
mm: page_vma_mapped_walk(): use goto instead of while (1)
mm: page_vma_mapped_walk(): add a level of indentation
mm: page_vma_mapped_walk(): crossing page table boundary
...
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The goal is to keep the mark during a bpf_redirect(), like it is done for
legacy encapsulation / decapsulation, when there is no x-netns.
This was initially done in commit 213dd74aee76 ("skbuff: Do not scrub skb
mark within the same name space").
When the call to skb_scrub_packet() was added in dev_forward_skb() (commit
8b27f27797ca ("skb: allow skb_scrub_packet() to be used by tunnels")), the
second argument (xnet) was set to true to force a call to skb_orphan(). At
this time, the mark was always cleanned up by skb_scrub_packet(), whatever
xnet value was.
This call to skb_orphan() was removed later in commit
9c4c325252c5 ("skbuff: preserve sock reference when scrubbing the skb.").
But this 'true' stayed here without any real reason.
Let's correctly set xnet in ____dev_forward_skb(), this function has access
to the previous interface and to the new interface.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Pull ceph fixes from Ilya Dryomov:
"Two regression fixes from the merge window: one in the auth code
affecting old clusters and one in the filesystem for proper
propagation of MDS request errors.
Also included a locking fix for async creates, marked for stable"
* tag 'ceph-for-5.13-rc8' of https://github.com/ceph/ceph-client:
libceph: set global_id as soon as we get an auth ticket
libceph: don't pass result into ac->ops->handle_reply()
ceph: fix error handling in ceph_atomic_open and ceph_lookup
ceph: must hold snap_rwsem when filling inode for async create
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git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 updates for v5.14.
- Add MTE support in guests, complete with tag save/restore interface
- Reduce the impact of CMOs by moving them in the page-table code
- Allow device block mappings at stage-2
- Reduce the footprint of the vmemmap in protected mode
- Support the vGIC on dumb systems such as the Apple M1
- Add selftest infrastructure to support multiple configuration
and apply that to PMU/non-PMU setups
- Add selftests for the debug architecture
- The usual crop of PMU fixes
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Expose the PEC calculation i2c_smbus_pec() for generic use.
Signed-off-by: Quan Nguyen <quan@os.amperecomputing.com>
Acked-by: Matt Johnston <matt@codeconstruct.com.au>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
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'x86/amd', 'virtio' and 'core' into next
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Passing a 64-bit address width to iommu_setup_dma_ops() is valid on
virtual platforms, but isn't currently possible. The overflow check in
iommu_dma_init_domain() prevents this even when @dma_base isn't 0. Pass
a limit address instead of a size, so callers don't have to fake a size
to work around the check.
The base and limit parameters are being phased out, because:
* they are redundant for x86 callers. dma-iommu already reserves the
first page, and the upper limit is already in domain->geometry.
* they can now be obtained from dev->dma_range_map on Arm.
But removing them on Arm isn't completely straightforward so is left for
future work. As an intermediate step, simplify the x86 callers by
passing dummy limits.
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20210618152059.1194210-5-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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The ACPI Virtual I/O Translation Table describes topology of
para-virtual platforms, similarly to vendor tables DMAR, IVRS and IORT.
For now it describes the relation between virtio-iommu and the endpoints
it manages.
Three steps are needed to configure DMA of endpoints:
(1) acpi_viot_init(): parse the VIOT table, find or create the fwnode
associated to each vIOMMU device. This needs to happen after
acpi_scan_init(), because it relies on the struct device and their
fwnode to be available.
(2) When probing the vIOMMU device, the driver registers its IOMMU ops
within the IOMMU subsystem. This step doesn't require any
intervention from the VIOT driver.
(3) viot_iommu_configure(): before binding the endpoint to a driver,
find the associated IOMMU ops. Register them, along with the
endpoint ID, into the device's iommu_fwspec.
If step (3) happens before step (2), it is deferred until the IOMMU is
initialized, then retried.
Tested-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20210618152059.1194210-4-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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Extract the code that sets up the IOMMU infrastructure from IORT, since
it can be reused by VIOT. Move it one level up into a new
acpi_iommu_configure_id() function, which calls the IORT parsing
function which in turn calls the acpi_iommu_fwspec_init() helper.
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20210618152059.1194210-3-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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Extract generic DMA setup code out of IORT, so it can be reused by VIOT.
Keep it in drivers/acpi/arm64 for now, since it could break x86
platforms that haven't run this code so far, if they have invalid
tables.
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/20210618152059.1194210-2-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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Add a hid_hw_may_wakeup() function, which is the equivalent of
device_may_wakeup() for hid devices.
In most cases this just returns device_may_wakeup(hdev->dev.parent), but for
some ll-drivers this is not correct. E.g. usb_hid_driver instantiated hid
devices have their parent set to the usb-interface to which the usb_hid_driver
is bound, but the power/wakeup* sysfs attributes are part of the usb-device,
which is the usb-interface's parent.
For these special cases a new may_wakeup callback is added to
hid_ll_driver, so that ll-drivers can override the default behavior.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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Some controllers like qcom geni need the parent device to be used for
dma mapping, so add a dma_map_dev field and let drivers fill this to be
used as mapping device
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20210625052213.32260-4-vkoul@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
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If someone includes linux/tty_flip.h before linux/tty.h, they see
many compiler errors like:
include/linux/tty_flip.h:23:30: error: invalid use of undefined type 'struct tty_port'
include/linux/tty_flip.h:26:14: error: invalid use of undefined type 'struct tty_buffer'
tty_flip.h actually lexicographically sorts before tty.h. So if people
sort includes (as I tried in amiserial), the compilation suddenly
breaks.
Solve this by including linux/tty.h from linux/tty_flip.h, so that
everything is defined as needed.
Another alternative would be to uninline tty_insert_flip_char and just
insert forward declarations of tty_port and tty_buffer structs into
tty_flip.h as that inline is the only real user. But that would mean
slowing down the fast path without any good reason. (Provided the fix
is that easy and there were no real problems with this until now.)
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210625073511.4514-1-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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If more than one futex is placed on a shmem huge page, it can happen
that waking the second wakes the first instead, and leaves the second
waiting: the key's shared.pgoff is wrong.
When 3.11 commit 13d60f4b6ab5 ("futex: Take hugepages into account when
generating futex_key"), the only shared huge pages came from hugetlbfs,
and the code added to deal with its exceptional page->index was put into
hugetlb source. Then that was missed when 4.8 added shmem huge pages.
page_to_pgoff() is what others use for this nowadays: except that, as
currently written, it gives the right answer on hugetlbfs head, but
nonsense on hugetlbfs tails. Fix that by calling hugetlbfs-specific
hugetlb_basepage_index() on PageHuge tails as well as on head.
Yes, it's unconventional to declare hugetlb_basepage_index() there in
pagemap.h, rather than in hugetlb.h; but I do not expect anything but
page_to_pgoff() ever to need it.
[akpm@linux-foundation.org: give hugetlb_basepage_index() prototype the correct scope]
Link: https://lkml.kernel.org/r/b17d946b-d09-326e-b42a-52884c36df32@google.com
Fixes: 800d8c63b2e9 ("shmem: add huge pages support")
Reported-by: Neel Natu <neelnatu@google.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Zhang Yi <wetpzy@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Patch series "mm: add vmalloc_no_huge and use it", v4.
Add vmalloc_no_huge() and export it, so modules can allocate memory with
small pages.
Use the newly added vmalloc_no_huge() in KVM on s390 to get around a
hardware limitation.
This patch (of 2):
Commit 121e6f3258fe3 ("mm/vmalloc: hugepage vmalloc mappings") added
support for hugepage vmalloc mappings, it also added the flag
VM_NO_HUGE_VMAP for __vmalloc_node_range to request the allocation to be
performed with 0-order non-huge pages.
This flag is not accessible when calling vmalloc, the only option is to
call directly __vmalloc_node_range, which is not exported.
This means that a module can't vmalloc memory with small pages.
Case in point: KVM on s390x needs to vmalloc a large area, and it needs
to be mapped with non-huge pages, because of a hardware limitation.
This patch adds the function vmalloc_no_huge, which works like vmalloc,
but it is guaranteed to always back the mapping using small pages. This
new function is exported, therefore it is usable by modules.
[akpm@linux-foundation.org: whitespace fixes, per Christoph]
Link: https://lkml.kernel.org/r/20210614132357.10202-1-imbrenda@linux.ibm.com
Link: https://lkml.kernel.org/r/20210614132357.10202-2-imbrenda@linux.ibm.com
Fixes: 121e6f3258fe3 ("mm/vmalloc: hugepage vmalloc mappings")
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Lockdep complains about lock inversion between ioc->lock and bfqd->lock:
bfqd -> ioc:
put_io_context+0x33/0x90 -> ioc->lock grabbed
blk_mq_free_request+0x51/0x140
blk_put_request+0xe/0x10
blk_attempt_req_merge+0x1d/0x30
elv_attempt_insert_merge+0x56/0xa0
blk_mq_sched_try_insert_merge+0x4b/0x60
bfq_insert_requests+0x9e/0x18c0 -> bfqd->lock grabbed
blk_mq_sched_insert_requests+0xd6/0x2b0
blk_mq_flush_plug_list+0x154/0x280
blk_finish_plug+0x40/0x60
ext4_writepages+0x696/0x1320
do_writepages+0x1c/0x80
__filemap_fdatawrite_range+0xd7/0x120
sync_file_range+0xac/0xf0
ioc->bfqd:
bfq_exit_icq+0xa3/0xe0 -> bfqd->lock grabbed
put_io_context_active+0x78/0xb0 -> ioc->lock grabbed
exit_io_context+0x48/0x50
do_exit+0x7e9/0xdd0
do_group_exit+0x54/0xc0
To avoid this inversion we change blk_mq_sched_try_insert_merge() to not
free the merged request but rather leave that upto the caller similarly
to blk_mq_sched_try_merge(). And in bfq_insert_requests() we make sure
to free all the merged requests after dropping bfqd->lock.
Fixes: aee69d78dec0 ("block, bfq: introduce the BFQ-v0 I/O scheduler as an extra scheduler")
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210623093634.27879-3-jack@suse.cz
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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To remove code duplication, use the binary stats descriptors in the
implementation of the debugfs interface for statistics. This unifies
the definition of statistics for the binary and debugfs interfaces.
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-8-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Add a VCPU ioctl to get a statistics file descriptor by which a read
functionality is provided for userspace to read out VCPU stats header,
descriptors and data.
Define VCPU statistics descriptors and header for all architectures.
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com> #arm64
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-5-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Add a VM ioctl to get a statistics file descriptor by which a read
functionality is provided for userspace to read out VM stats header,
descriptors and data.
Define VM statistics descriptors and header for all architectures.
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com> #arm64
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-4-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Other places in the kernel use this form, and so just
provide a common path for it.
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Link: https://lore.kernel.org/r/20210623022824.308041-2-mcgrof@kernel.org
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Commit 61ca49a9105f ("libceph: don't set global_id until we get an
auth ticket") delayed the setting of global_id too much. It is set
only after all tickets are received, but in pre-nautilus clusters an
auth ticket and the service tickets are obtained in separate steps
(for a total of three MAuth replies). When the service tickets are
requested, global_id is used to build an authorizer; if global_id is
still 0 we never get them and fail to establish the session.
Moving the setting of global_id into protocol implementations. This
way global_id can be set exactly when an auth ticket is received, not
sooner nor later.
Fixes: 61ca49a9105f ("libceph: don't set global_id until we get an auth ticket")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
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There is no result to pass in msgr2 case because authentication
failures are reported through auth_bad_method frame and in MAuth
case an error is returned immediately.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
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The fallback case of fwnode_mdbiobus_register()
(relevant for !CONFIG_FWNODE_MDIO) was defined with wrong
argument name, causing a compilation error. Fix that.
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
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bdev_disk_changed can only operate on whole devices. Make that clear
by passing a gendisk instead of the struct block_device.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210624123240.441814-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Move bdev_disk_changed to block/partitions/core.c, together with the
rest of the partition scanning code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210624123240.441814-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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XDP_REDIRECT works by a three-step process: the bpf_redirect() and
bpf_redirect_map() helpers will lookup the target of the redirect and store
it (along with some other metadata) in a per-CPU struct bpf_redirect_info.
Next, when the program returns the XDP_REDIRECT return code, the driver
will call xdp_do_redirect() which will use the information thus stored to
actually enqueue the frame into a bulk queue structure (that differs
slightly by map type, but shares the same principle). Finally, before
exiting its NAPI poll loop, the driver will call xdp_do_flush(), which will
flush all the different bulk queues, thus completing the redirect.
Pointers to the map entries will be kept around for this whole sequence of
steps, protected by RCU. However, there is no top-level rcu_read_lock() in
the core code; instead drivers add their own rcu_read_lock() around the XDP
portions of the code, but somewhat inconsistently as Martin discovered[0].
However, things still work because everything happens inside a single NAPI
poll sequence, which means it's between a pair of calls to
local_bh_disable()/local_bh_enable(). So Paul suggested[1] that we could
document this intention by using rcu_dereference_check() with
rcu_read_lock_bh_held() as a second parameter, thus allowing sparse and
lockdep to verify that everything is done correctly.
This patch does just that: we add an __rcu annotation to the map entry
pointers and remove the various comments explaining the NAPI poll assurance
strewn through devmap.c in favour of a longer explanation in filter.c. The
goal is to have one coherent documentation of the entire flow, and rely on
the RCU annotations as a "standard" way of communicating the flow in the
map code (which can additionally be understood by sparse and lockdep).
The RCU annotation replacements result in a fairly straight-forward
replacement where READ_ONCE() becomes rcu_dereference_check(), WRITE_ONCE()
becomes rcu_assign_pointer() and xchg() and cmpxchg() gets wrapped in the
proper constructs to cast the pointer back and forth between __rcu and
__kernel address space (for the benefit of sparse). The one complication is
that xskmap has a few constructions where double-pointers are passed back
and forth; these simply all gain __rcu annotations, and only the final
reference/dereference to the inner-most pointer gets changed.
With this, everything can be run through sparse without eliciting
complaints, and lockdep can verify correctness even without the use of
rcu_read_lock() in the drivers. Subsequent patches will clean these up from
the drivers.
[0] https://lore.kernel.org/bpf/20210415173551.7ma4slcbqeyiba2r@kafai-mbp.dhcp.thefacebook.com/
[1] https://lore.kernel.org/bpf/20210419165837.GA975577@paulmck-ThinkPad-P17-Gen-1/
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210624160609.292325-6-toke@redhat.com
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The xchg() and cmpxchg() functions are sometimes used to carry out RCU
updates. Unfortunately, this can result in sparse warnings for both
the old-value and new-value arguments, as well as for the return value.
The arguments can be dealt with using RCU_INITIALIZER():
old_p = xchg(&p, RCU_INITIALIZER(new_p));
But a sparse warning still remains due to assigning the __rcu pointer
returned from xchg to the (most likely) non-__rcu pointer old_p.
This commit therefore provides an unrcu_pointer() macro that strips
the __rcu. This macro can be used as follows:
old_p = unrcu_pointer(xchg(&p, RCU_INITIALIZER(new_p)));
Reported-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210624160609.292325-2-toke@redhat.com
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This commit defines the API for userspace and prepare the common
functionalities to support per VM/VCPU binary stats data readings.
The KVM stats now is only accessible by debugfs, which has some
shortcomings this change series are supposed to fix:
1. The current debugfs stats solution in KVM could be disabled
when kernel Lockdown mode is enabled, which is a potential
rick for production.
2. The current debugfs stats solution in KVM is organized as "one
stats per file", it is good for debugging, but not efficient
for production.
3. The stats read/clear in current debugfs solution in KVM are
protected by the global kvm_lock.
Besides that, there are some other benefits with this change:
1. All KVM VM/VCPU stats can be read out in a bulk by one copy
to userspace.
2. A schema is used to describe KVM statistics. From userspace's
perspective, the KVM statistics are self-describing.
3. With the fd-based solution, a separate telemetry would be able
to read KVM stats in a less privileged environment.
4. After the initial setup by reading in stats descriptors, a
telemetry only needs to read the stats data itself, no more
parsing or setup is needed.
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com> #arm64
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-3-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Generic KVM stats are those collected in architecture independent code
or those supported by all architectures; put all generic statistics in
a separate structure. This ensures that they are defined the same way
in the statistics API which is being added, removing duplication among
different architectures in the declaration of the descriptors.
No functional change intended.
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-2-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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After remove the unique user of sop->bdev_try_to_free_page() callback,
we could remove the callback and the corresponding blkdev_releasepage()
at all.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210610112440.3438139-9-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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Current metadata buffer release logic in bdev_try_to_free_page() have
a lot of use-after-free issues when umount filesystem concurrently, and
it is difficult to fix directly because ext4 is the only user of
s_op->bdev_try_to_free_page callback and we may have to add more special
refcount or lock that is only used by ext4 into the common vfs layer,
which is unacceptable.
One better solution is remove the bdev_try_to_free_page callback, but
the real problem is we cannot easily release journal_head on the
checkpointed buffer, so try_to_free_buffers() cannot release buffers and
page under memory pressure, which is more likely to trigger
out-of-memory. So we cannot remove the callback directly before we find
another way to release journal_head.
This patch introduce a shrinker to free journal_head on the checkpointed
transaction. After the journal_head got freed, try_to_free_buffers()
could free buffer properly.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210610112440.3438139-6-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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buffer back
Although we merged c044f3d8360 ("jbd2: abort journal if free a async
write error metadata buffer"), there is a race between
jbd2_journal_try_to_free_buffers() and jbd2_journal_destroy(), so the
jbd2_log_do_checkpoint() may still fail to detect the buffer write
io error flag which may lead to filesystem inconsistency.
jbd2_journal_try_to_free_buffers() ext4_put_super()
jbd2_journal_destroy()
__jbd2_journal_remove_checkpoint()
detect buffer write error jbd2_log_do_checkpoint()
jbd2_cleanup_journal_tail()
<--- lead to inconsistency
jbd2_journal_abort()
Fix this issue by introducing a new atomic flag which only have one
JBD2_CHECKPOINT_IO_ERROR bit now, and set it in
__jbd2_journal_remove_checkpoint() when freeing a checkpoint buffer
which has write_io_error flag. Then jbd2_journal_destroy() will detect
this mark and abort the journal to prevent updating log tail.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210610112440.3438139-3-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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Drop the repeated word "the" in a comment.
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[alexander.shishkin: fixed the commit message]
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Link: https://lore.kernel.org/r/20210621151246.31891-2-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Map them to KEY_MACRO# event codes.
These buttons are defined by HID as follows:
"The user defines the function of these buttons to control software applications or GUI objects."
This matches the semantics of the KEY_MACRO# input event codes that Linux supports.
Also add support for HID "Named Array" collections.
Also add hid-debug support for KEY_MACRO#.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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Docs for struct dma_resv are fairly clear:
"A reservation object can have attached one exclusive fence (normally
associated with write operations) or N shared fences (read
operations)."
https://dri.freedesktop.org/docs/drm/driver-api/dma-buf.html#reservation-objects
Furthermore a review across all of upstream.
First of render drivers and how they set implicit fences:
- nouveau follows this contract, see in validate_fini_no_ticket()
nouveau_bo_fence(nvbo, fence, !!b->write_domains);
and that last boolean controls whether the exclusive or shared fence
slot is used.
- radeon follows this contract by setting
p->relocs[i].tv.num_shared = !r->write_domain;
in radeon_cs_parser_relocs(), which ensures that the call to
ttm_eu_fence_buffer_objects() in radeon_cs_parser_fini() will do the
right thing.
- vmwgfx seems to follow this contract with the shotgun approach of
always setting ttm_val_buf->num_shared = 0, which means
ttm_eu_fence_buffer_objects() will only use the exclusive slot.
- etnaviv follows this contract, as can be trivially seen by looking
at submit_attach_object_fences()
- i915 is a bit a convoluted maze with multiple paths leading to
i915_vma_move_to_active(). Which sets the exclusive flag if
EXEC_OBJECT_WRITE is set. This can either come as a buffer flag for
softpin mode, or through the write_domain when using relocations. It
follows this contract.
- lima follows this contract, see lima_gem_submit() which sets the
exclusive fence when the LIMA_SUBMIT_BO_WRITE flag is set for that
bo
- msm follows this contract, see msm_gpu_submit() which sets the
exclusive flag when the MSM_SUBMIT_BO_WRITE is set for that buffer
- panfrost follows this contract with the shotgun approach of just
always setting the exclusive fence, see
panfrost_attach_object_fences(). Benefits of a single engine I guess
- v3d follows this contract with the same shotgun approach in
v3d_attach_fences_and_unlock_reservation(), but it has at least an
XXX comment that maybe this should be improved
- v4c uses the same shotgun approach of always setting an exclusive
fence, see vc4_update_bo_seqnos()
- vgem also follows this contract, see vgem_fence_attach_ioctl() and
the VGEM_FENCE_WRITE. This is used in some igts to validate prime
sharing with i915.ko without the need of a 2nd gpu
- vritio follows this contract again with the shotgun approach of
always setting an exclusive fence, see virtio_gpu_array_add_fence()
This covers the setting of the exclusive fences when writing.
Synchronizing against the exclusive fence is a lot more tricky, and I
only spot checked a few:
- i915 does it, with the optional EXEC_OBJECT_ASYNC to skip all
implicit dependencies (which is used by vulkan)
- etnaviv does this. Implicit dependencies are collected in
submit_fence_sync(), again with an opt-out flag
ETNA_SUBMIT_NO_IMPLICIT. These are then picked up in
etnaviv_sched_dependency which is the
drm_sched_backend_ops->dependency callback.
- v4c seems to not do much here, maybe gets away with it by not having
a scheduler and only a single engine. Since all newer broadcom chips than
the OG vc4 use v3d for rendering, which follows this contract, the
impact of this issue is fairly small.
- v3d does this using the drm_gem_fence_array_add_implicit() helper,
which then it's drm_sched_backend_ops->dependency callback
v3d_job_dependency() picks up.
- panfrost is nice here and tracks the implicit fences in
panfrost_job->implicit_fences, which again the
drm_sched_backend_ops->dependency callback panfrost_job_dependency()
picks up. It is mildly questionable though since it only picks up
exclusive fences in panfrost_acquire_object_fences(), but not buggy
in practice because it also always sets the exclusive fence. It
should pick up both sets of fences, just in case there's ever going
to be a 2nd gpu in a SoC with a mali gpu. Or maybe a mali SoC with a
pcie port and a real gpu, which might actually happen eventually. A
bug, but easy to fix. Should probably use the
drm_gem_fence_array_add_implicit() helper.
- lima is nice an easy, uses drm_gem_fence_array_add_implicit() and
the same schema as v3d.
- msm is mildly entertaining. It also supports MSM_SUBMIT_NO_IMPLICIT,
but because it doesn't use the drm/scheduler it handles fences from
the wrong context with a synchronous dma_fence_wait. See
submit_fence_sync() leading to msm_gem_sync_object(). Investing into
a scheduler might be a good idea.
- all the remaining drivers are ttm based, where I hope they do
appropriately obey implicit fences already. I didn't do the full
audit there because a) not follow the contract would confuse ttm
quite well and b) reading non-standard scheduler and submit code
which isn't based on drm/scheduler is a pain.
Onwards to the display side.
- Any driver using the drm_gem_plane_helper_prepare_fb() helper will
correctly. Overwhelmingly most drivers get this right, except a few
totally dont. I'll follow up with a patch to make this the default
and avoid a bunch of bugs.
- I didn't audit the ttm drivers, but given that dma_resv started
there I hope they get this right.
In conclusion this IS the contract, both as documented and
overwhelmingly implemented, specically as implemented by all render
drivers except amdgpu.
Amdgpu tried to fix this already in
commit 049aca4363d8af87cab8d53de5401602db3b9999
Author: Christian König <christian.koenig@amd.com>
Date: Wed Sep 19 16:54:35 2018 +0200
drm/amdgpu: fix using shared fence for exported BOs v2
but this fix falls short on a number of areas:
- It's racy, by the time the buffer is shared it might be too late. To
make sure there's definitely never a problem we need to set the
fences correctly for any buffer that's potentially exportable.
- It's breaking uapi, dma-buf fds support poll() and differentitiate
between, which was introduced in
commit 9b495a5887994a6d74d5c261d012083a92b94738
Author: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Date: Tue Jul 1 12:57:43 2014 +0200
dma-buf: add poll support, v3
- Christian König wants to nack new uapi building further on this
dma_resv contract because it breaks amdgpu, quoting
"Yeah, and that is exactly the reason why I will NAK this uAPI change.
"This doesn't works for amdgpu at all for the reasons outlined above."
https://lore.kernel.org/dri-devel/f2eb6751-2f82-9b23-f57e-548de5b729de@gmail.com/
Rejecting new development because your own driver is broken and
violates established cross driver contracts and uapi is really not
how upstream works.
Now this patch will have a severe performance impact on anything that
runs on multiple engines. So we can't just merge it outright, but need
a bit a plan:
- amdgpu needs a proper uapi for handling implicit fencing. The funny
thing is that to do it correctly, implicit fencing must be treated
as a very strange IPC mechanism for transporting fences, where both
setting the fence and dependency intercepts must be handled
explicitly. Current best practices is a per-bo flag to indicate
writes, and a per-bo flag to to skip implicit fencing in the CS
ioctl as a new chunk.
- Since amdgpu has been shipping with broken behaviour we need an
opt-out flag from the butchered implicit fencing model to enable the
proper explicit implicit fencing model.
- for kernel memory fences due to bo moves at least the i915 idea is
to use ttm_bo->moving. amdgpu probably needs the same.
- since the current p2p dma-buf interface assumes the kernel memory
fence is in the exclusive dma_resv fence slot we need to add a new
fence slot for kernel fences, which must never be ignored. Since
currently only amdgpu supports this there's no real problem here
yet, until amdgpu gains a NO_IMPLICIT CS flag.
- New userspace needs to ship in enough desktop distros so that users
wont notice the perf impact. I think we can ignore LTS distros who
upgrade their kernels but not their mesa3d snapshot.
- Then when this is all in place we can merge this patch here.
What is not a solution to this problem here is trying to make the
dma_resv rules in the kernel more clever. The fundamental issue here
is that the amdgpu CS uapi is the least expressive one across all
drivers (only equalled by panfrost, which has an actual excuse) by not
allowing any userspace control over how implicit sync is conducted.
Until this is fixed it's completely pointless to make the kernel more
clever to improve amdgpu, because all we're doing is papering over
this uapi design issue. amdgpu needs to attain the status quo
established by other drivers first, once that's achieved we can tackle
the remaining issues in a consistent way across drivers.
v2: Bas pointed me at AMDGPU_GEM_CREATE_EXPLICIT_SYNC, which I
entirely missed.
This is great because it means the amdgpu specific piece for proper
implicit fence handling exists already, and that since a while. The
only thing that's now missing is
- fishing the implicit fences out of a shared object at the right time
- setting the exclusive implicit fence slot at the right time.
Jason has a patch series to fill that gap with a bunch of generic
ioctl on the dma-buf fd:
https://lore.kernel.org/dri-devel/20210520190007.534046-1-jason@jlekstrand.net/
v3: Since Christian has fixed amdgpu now in
commit 8c505bdc9c8b955223b054e34a0be9c3d841cd20 (drm-misc/drm-misc-next)
Author: Christian König <christian.koenig@amd.com>
Date: Wed Jun 9 13:51:36 2021 +0200
drm/amdgpu: rework dma_resv handling v3
Use the audit covered in this commit message as the excuse to update
the dma-buf docs around dma_buf.resv usage across drivers.
Since dynamic importers have different rules also hammer these in
again while we're at it.
v4:
- Add the missing "through the device" in the dynamic section that I
overlooked.
- Fix a kerneldoc markup mistake, the link didn't connect
v5:
- A few s/should/must/ to make clear what must be done (if the driver
does implicit sync) and what's more a maybe (Daniel Stone)
- drop all the example api discussion, that needs to be expanded,
clarified and put into a new chapter in drm-uapi.rst (Daniel Stone)
Cc: Daniel Stone <daniel@fooishbar.org>
Acked-by: Daniel Stone <daniel@fooishbar.org>
Reviewed-by: Dave Airlie <airlied@redhat.com> (v4)
Reviewed-by: Christian König <christian.koenig@amd.com> (v3)
Cc: mesa-dev@lists.freedesktop.org
Cc: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Rob Clark <robdclark@chromium.org>
Cc: Kristian H. Kristensen <hoegsberg@google.com>
Cc: Michel Dänzer <michel@daenzer.net>
Cc: Daniel Stone <daniels@collabora.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Deepak R Varma <mh12gx2825@gmail.com>
Cc: Chen Li <chenli@uniontech.com>
Cc: Kevin Wang <kevin1.wang@amd.com>
Cc: Dennis Li <Dennis.Li@amd.com>
Cc: Luben Tuikov <luben.tuikov@amd.com>
Cc: linaro-mm-sig@lists.linaro.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210624125246.166721-1-daniel.vetter@ffwll.ch
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Also review & update everything while we're at it.
This is prep work to smash a ton of stuff into the kerneldoc for
@resv.
v2: Move the doc for sysfs_entry.attachment_uid to the right place too
(Sam)
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Christian König <christian.koenig@amd.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Nirmoy Das <nirmoy.das@amd.com>
Cc: Deepak R Varma <mh12gx2825@gmail.com>
Cc: Chen Li <chenli@uniontech.com>
Cc: Kevin Wang <kevin1.wang@amd.com>
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Link: https://patchwork.freedesktop.org/patch/msgid/20210623161712.3370885-1-daniel.vetter@ffwll.ch
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Add support for versions v1.2 and 1.3 of the SMC calling convention.
* for-next/smccc:
arm64: smccc: Support SMCCC v1.3 SVE register saving hint
arm64: smccc: Add support for SMCCCv1.2 extended input/output registers
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PMU driver cleanups for managing IRQ affinity and exposing event
attributes via sysfs.
* for-next/perf: (36 commits)
drivers/perf: fix the missed ida_simple_remove() in ddr_perf_probe()
perf/arm-cmn: Fix invalid pointer when access dtc object sharing the same IRQ number
arm64: perf: Simplify EVENT ATTR macro in perf_event.c
drivers/perf: Simplify EVENT ATTR macro in fsl_imx8_ddr_perf.c
drivers/perf: Simplify EVENT ATTR macro in xgene_pmu.c
drivers/perf: Simplify EVENT ATTR macro in qcom_l3_pmu.c
drivers/perf: Simplify EVENT ATTR macro in qcom_l2_pmu.c
drivers/perf: Simplify EVENT ATTR macro in SMMU PMU driver
perf: Add EVENT_ATTR_ID to simplify event attributes
perf/smmuv3: Don't trample existing events with global filter
perf/hisi: Constify static attribute_group structs
perf: qcom: Remove redundant dev_err call in qcom_l3_cache_pmu_probe()
drivers/perf: hisi: Fix data source control
arm64: perf: Add more support on caps under sysfs
perf: qcom_l2_pmu: move to use request_irq by IRQF_NO_AUTOEN flag
arm_pmu: move to use request_irq by IRQF_NO_AUTOEN flag
perf: arm_spe: use DEVICE_ATTR_RO macro
perf: xgene_pmu: use DEVICE_ATTR_RO macro
perf: qcom: use DEVICE_ATTR_RO macro
perf: arm_pmu: use DEVICE_ATTR_RO macro
...
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Since commit 6c5f05a6cd88 ("ARM: imx3: Remove imx3 soc_init()")
there are no more users of struct sdma_script_start_addrs outside
of the driver itself, thus let's move the struct declaration just
to the driver source code and remove the header file as unused one.
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/r/20210620191103.156626-1-vz@mleia.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
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