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Cited commit mistakenly removed the trap group for externally routed
packets (e.g., via the management interface) and grouped locally routed
and externally routed packet traps under the same group, thereby
subjecting them to the same policer.
This can result in problems, for example, when FRR is restarted and
suddenly all transient traffic is trapped to the CPU because of a
default route through the management interface. Locally routed packets
required to re-establish a BGP connection will never reach the CPU and
the routing tables will not be re-populated.
Fix this by using a different trap group for externally routed packets.
Fixes: 8110668ecd9a ("mlxsw: spectrum_trap: Register layer 3 control traps")
Reported-by: Alex Veber <alexve@mellanox.com>
Tested-by: Alex Veber <alexve@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The lookaside count is improperly initialized to the size of the
Receive Queue with the additional +1. In the traces below, the
RQ size is 384, so the count was set to 385.
The lookaside count is then rarely refreshed. Note the high and
incorrect count in the trace below:
rvt_get_rwqe: [hfi1_0] wqe ffffc900078e9008 wr_id 55c7206d75a0 qpn c
qpt 2 pid 3018 num_sge 1 head 1 tail 0, count 385
rvt_get_rwqe: (hfi1_rc_rcv+0x4eb/0x1480 [hfi1] <- rvt_get_rwqe) ret=0x1
The head,tail indicate there is only one RWQE posted although the count
says 385 and we correctly return the element 0.
The next call to rvt_get_rwqe with the decremented count:
rvt_get_rwqe: [hfi1_0] wqe ffffc900078e9058 wr_id 0 qpn c
qpt 2 pid 3018 num_sge 0 head 1 tail 1, count 384
rvt_get_rwqe: (hfi1_rc_rcv+0x4eb/0x1480 [hfi1] <- rvt_get_rwqe) ret=0x1
Note that the RQ is empty (head == tail) yet we return the RWQE at tail 1,
which is not valid because of the bogus high count.
Best case, the RWQE has never been posted and the rc logic sees an RWQE
that is too small (all zeros) and puts the QP into an error state.
In the worst case, a server slow at posting receive buffers might fool
rvt_get_rwqe() into fetching an old RWQE and corrupt memory.
Fix by deleting the faulty initialization code and creating an
inline to fetch the posted count and convert all callers to use
new inline.
Fixes: f592ae3c999f ("IB/rdmavt: Fracture single lock used for posting and processing RWQEs")
Link: https://lore.kernel.org/r/20200728183848.22226.29132.stgit@awfm-01.aw.intel.com
Reported-by: Zhaojuan Guo <zguo@redhat.com>
Cc: <stable@vger.kernel.org> # 5.4.x
Reviewed-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Tested-by: Honggang Li <honli@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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into master
Pull drm fixes from Dave Airlie:
"The nouveau fixes missed the last pull by a few hours, and we had a
few arm driver/panel/bridge fixes come in.
This is possibly a bit more than I'm comfortable sending at this
stage, but I've looked at each patch, the core + nouveau patches fix
regressions, and the arm related ones are all around screens turning
on and working, and are mostly trivial patches, the line count is
mostly in comments.
core:
- fix possible use-after-free
drm_fb_helper:
- regression fix to use memcpy_io on bochs' sparc64
nouveau:
- format modifiers fixes
- HDA regression fix
- turing modesetting race fix
of:
- fix a double free
dbi:
- fix SPI Type 1 transfer
mcde:
- fix screen stability crash
panel:
- panel: fix display noise on auo,kd101n80-45na
- panel: delay HPD checks for boe_nv133fhm_n61
bridge:
- bridge: drop connector check in nwl-dsi bridge
- bridge: set proper bridge type for adv7511"
* tag 'drm-fixes-2020-07-29' of git://anongit.freedesktop.org/drm/drm:
drm: hold gem reference until object is no longer accessed
drm/dbi: Fix SPI Type 1 (9-bit) transfer
drm/drm_fb_helper: fix fbdev with sparc64
drm/mcde: Fix stability issue
drm/bridge: nwl-dsi: Drop DRM_BRIDGE_ATTACH_NO_CONNECTOR check.
drm/panel: Fix auo, kd101n80-45na horizontal noise on edges of panel
drm: panel: simple: Delay HPD checking on boe_nv133fhm_n61 for 15 ms
drm/bridge/adv7511: set the bridge type properly
drm: of: Fix double-free bug
drm/nouveau/fbcon: zero-initialise the mode_cmd2 structure
drm/nouveau/fbcon: fix module unload when fbcon init has failed for some reason
drm/nouveau/kms/tu102: wait for core update to complete when assigning windows
drm/nouveau/kms/gf100: use correct format modifiers
drm/nouveau/disp/gm200-: fix regression from HDA SOR selection changes
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Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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The header files in RDMA subsystem are dual licensed and can be
described by simple SPDX tag, so replace all of them at once
together with making them use the same coding style for header
guard defines.
Link: https://lore.kernel.org/r/20200719072521.135260-1-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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This modifies the first 32 bits out of the 128 bits of a random CPU's
net_rand_state on interrupt or CPU activity to complicate remote
observations that could lead to guessing the network RNG's internal
state.
Note that depending on some network devices' interrupt rate moderation
or binding, this re-seeding might happen on every packet or even almost
never.
In addition, with NOHZ some CPUs might not even get timer interrupts,
leaving their local state rarely updated, while they are running
networked processes making use of the random state. For this reason, we
also perform this update in update_process_times() in order to at least
update the state when there is user or system activity, since it's the
only case we care about.
Reported-by: Amit Klein <aksecurity@gmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Control Flow Integrity(CFI) is a security mechanism that disallows
changes to the original control flow graph of a compiled binary,
making it significantly harder to perform such attacks.
init_state_node() assign same function callback to different
function pointer declarations.
static int init_state_node(struct cpuidle_state *idle_state,
const struct of_device_id *matches,
struct device_node *state_node) { ...
idle_state->enter = match_id->data; ...
idle_state->enter_s2idle = match_id->data; }
Function declarations:
struct cpuidle_state { ...
int (*enter) (struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index);
void (*enter_s2idle) (struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index); };
In this case, either enter() or enter_s2idle() would cause CFI check
failed since they use same callee.
Align function prototype of enter() since it needs return value for
some use cases. The return value of enter_s2idle() is no
need currently.
Signed-off-by: Neal Liu <neal.liu@mediatek.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Some platforms can be designed in a way so the UART port reference clock
might be asynchronously changed at some point. In Baikal-T1 SoC this may
happen due to the reference clock being shared between two UART ports, on
the Allwinner SoC the reference clock is derived from the CPU clock, so
any CPU frequency change should get to be known/reflected by/in the UART
controller as well. But it's not enough to just update the
uart_port->uartclk field of the corresponding UART port, the 8250
controller reference clock divisor should be altered so to preserve
current baud rate setting. All of these things is done in a coherent
way by calling the serial8250_update_uartclk() method provided in this
patch. Though note that it isn't supposed to be called from within the
UART port callbacks because the locks using to the protect the UART port
data are already taken in there.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20200723003357.26897-2-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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For nvmem providers which have multiple instances, it is required
to suffix the provider name with proper id, so that they do not
confict for the same name. Currently the core does not handle
this case properly eventhough core already has logic to generate the id.
This patch add new devid type NVMEM_DEVID_AUTO for providers to be
able to allow core to assign id and append it to provier name.
Reported-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Link: https://lore.kernel.org/r/20200722100705.7772-8-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Complement the u16, u32 and u64 helpers with a u8 variant to ease
accessing byte-sized values.
This helper will be useful for Realtek Digital Home Center platforms,
which store some byte and sub-byte sized values in non-volatile memory.
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200722100705.7772-7-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Attempt uniformity and brevity.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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Less is more.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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Manual repetition is boring and error prone.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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Manual repetition is boring and error prone.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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__SEQ_LOCKDEP() is an expression gate for the
seqcount_LOCKNAME_t::lock member. Rename it to be about the member,
not the gate condition.
Later (PREEMPT_RT) patches will make the member available for !LOCKDEP
configs.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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A sequence counter write side critical section must be protected by some
form of locking to serialize writers. A plain seqcount_t does not
contain the information of which lock must be held when entering a write
side critical section.
Use the new seqcount_raw_spinlock_t data type, which allows to associate
a raw spinlock with the sequence counter. This enables lockdep to verify
that the raw spinlock used for writer serialization is held when the
write side critical section is entered.
If lockdep is disabled this lock association is compiled out and has
neither storage size nor runtime overhead.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-25-a.darwish@linutronix.de
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A sequence counter write side critical section must be protected by some
form of locking to serialize writers. A plain seqcount_t does not
contain the information of which lock must be held when entering a write
side critical section.
Use the new seqcount_spinlock_t data type, which allows to associate a
spinlock with the sequence counter. This enables lockdep to verify that
the spinlock used for writer serialization is held when the write side
critical section is entered.
If lockdep is disabled this lock association is compiled out and has
neither storage size nor runtime overhead.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://lkml.kernel.org/r/20200720155530.1173732-24-a.darwish@linutronix.de
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A sequence counter write side critical section must be protected by some
form of locking to serialize writers. A plain seqcount_t does not
contain the information of which lock must be held when entering a write
side critical section.
Use the new seqcount_spinlock_t data type, which allows to associate a
spinlock with the sequence counter. This enables lockdep to verify that
the spinlock used for writer serialization is held when the write side
critical section is entered.
If lockdep is disabled this lock association is compiled out and has
neither storage size nor runtime overhead.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-19-a.darwish@linutronix.de
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A sequence counter write side critical section must be protected by some
form of locking to serialize writers. A plain seqcount_t does not
contain the information of which lock must be held when entering a write
side critical section.
Use the new seqcount_spinlock_t data type, which allows to associate a
spinlock with the sequence counter. This enables lockdep to verify that
the spinlock used for writer serialization is held when the write side
critical section is entered.
If lockdep is disabled this lock association is compiled out and has
neither storage size nor runtime overhead.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-15-a.darwish@linutronix.de
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A sequence counter write side critical section must be protected by some
form of locking to serialize writers. A plain seqcount_t does not
contain the information of which lock must be held when entering a write
side critical section.
Use the new seqcount_spinlock_t data type, which allows to associate a
spinlock with the sequence counter. This enables lockdep to verify that
the spinlock used for writer serialization is held when the write side
critical section is entered.
If lockdep is disabled this lock association is compiled out and has
neither storage size nor runtime overhead.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-14-a.darwish@linutronix.de
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A sequence counter write side critical section must be protected by some
form of locking to serialize writers. If the serialization primitive is
not disabling preemption implicitly, preemption has to be explicitly
disabled before entering the sequence counter write side critical
section.
The dma-buf reservation subsystem uses plain sequence counters to manage
updates to reservations. Writer serialization is accomplished through a
wound/wait mutex.
Acquiring a wound/wait mutex does not disable preemption, so this needs
to be done manually before and after the write side critical section.
Use the newly-added seqcount_ww_mutex_t instead:
- It associates the ww_mutex with the sequence count, which enables
lockdep to validate that the write side critical section is properly
serialized.
- It removes the need to explicitly add preempt_disable/enable()
around the write side critical section because the write_begin/end()
functions for this new data type automatically do this.
If lockdep is disabled this ww_mutex lock association is compiled out
and has neither storage size nor runtime overhead.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://lkml.kernel.org/r/20200720155530.1173732-13-a.darwish@linutronix.de
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Commit 3c3b177a9369 ("reservation: add support for read-only access
using rcu") introduced a sequence counter to manage updates to
reservations. Back then, the reservation object initializer
reservation_object_init() was always inlined.
Having the sequence counter initialization inlined meant that each of
the call sites would have a different lockdep class key, which would've
broken lockdep's deadlock detection. The aforementioned commit thus
introduced, and exported, a custom seqcount lockdep class key and name.
The commit 8735f16803f00 ("dma-buf: cleanup reservation_object_init...")
transformed the reservation object initializer to a normal non-inlined C
function. seqcount_init(), which automatically defines the seqcount
lockdep class key and must be called non-inlined, can now be safely used.
Remove the seqcount custom lockdep class key, name, and export. Use
seqcount_init() inside the dma reservation object initializer.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://lkml.kernel.org/r/20200720155530.1173732-12-a.darwish@linutronix.de
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Parent commit, "seqlock: Extend seqcount API with associated locks",
introduced a big number of multi-line macros that are newline-escaped
at 72 columns.
For overall cohesion, align the earlier-existing macros similarly.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-11-a.darwish@linutronix.de
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A sequence counter write side critical section must be protected by some
form of locking to serialize writers. If the serialization primitive is
not disabling preemption implicitly, preemption has to be explicitly
disabled before entering the write side critical section.
There is no built-in debugging mechanism to verify that the lock used
for writer serialization is held and preemption is disabled. Some usage
sites like dma-buf have explicit lockdep checks for the writer-side
lock, but this covers only a small portion of the sequence counter usage
in the kernel.
Add new sequence counter types which allows to associate a lock to the
sequence counter at initialization time. The seqcount API functions are
extended to provide appropriate lockdep assertions depending on the
seqcount/lock type.
For sequence counters with associated locks that do not implicitly
disable preemption, preemption protection is enforced in the sequence
counter write side functions. This removes the need to explicitly add
preempt_disable/enable() around the write side critical sections: the
write_begin/end() functions for these new sequence counter types
automatically do this.
Introduce the following seqcount types with associated locks:
seqcount_spinlock_t
seqcount_raw_spinlock_t
seqcount_rwlock_t
seqcount_mutex_t
seqcount_ww_mutex_t
Extend the seqcount read and write functions to branch out to the
specific seqcount_LOCKTYPE_t implementation at compile-time. This avoids
kernel API explosion per each new seqcount_LOCKTYPE_t added. Add such
compile-time type detection logic into a new, internal, seqlock header.
Document the proper seqcount_LOCKTYPE_t usage, and rationale, at
Documentation/locking/seqlock.rst.
If lockdep is disabled, this lock association is compiled out and has
neither storage size nor runtime overhead.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-10-a.darwish@linutronix.de
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Preemption must be disabled before entering a sequence count write side
critical section. Failing to do so, the seqcount read side can preempt
the write side section and spin for the entire scheduler tick. If that
reader belongs to a real-time scheduling class, it can spin forever and
the kernel will livelock.
Assert through lockdep that preemption is disabled for seqcount writers.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-9-a.darwish@linutronix.de
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Asserting that preemption is enabled or disabled is a critical sanity
check. Developers are usually reluctant to add such a check in a
fastpath as reading the preemption count can be costly.
Extend the lockdep API with macros asserting that preemption is disabled
or enabled. If lockdep is disabled, or if the underlying architecture
does not support kernel preemption, this assert has no runtime overhead.
References: f54bb2ec02c8 ("locking/lockdep: Add IRQs disabled/enabled assertion APIs: ...")
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-8-a.darwish@linutronix.de
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raw_seqcount_begin() has the same code as raw_read_seqcount(), with the
exception of masking the sequence counter's LSB before returning it to
the caller.
Note, raw_seqcount_begin() masks the counter's LSB before returning it
to the caller so that read_seqcount_retry() can fail if the counter is
odd -- without the overhead of an extra branching instruction.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-7-a.darwish@linutronix.de
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seqlock.h is now included by kernel's RST documentation, but a small
number of the the exported seqlock.h functions are kernel-doc annotated.
Add kernel-doc for all seqlock.h exported APIs.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-6-a.darwish@linutronix.de
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The seqlock.h seqcount_t and seqlock_t API definitions are presented in
the chronological order of their development rather than the order that
makes most sense to readers. This makes it hard to follow and understand
the header file code.
Group and reorder all of the exported seqlock.h functions according to
their function.
First, group together the seqcount_t standard read path functions:
- __read_seqcount_begin()
- raw_read_seqcount_begin()
- read_seqcount_begin()
since each function is implemented exactly in terms of the one above
it. Then, group the special-case seqcount_t readers on their own as:
- raw_read_seqcount()
- raw_seqcount_begin()
since the only difference between the two functions is that the second
one masks the sequence counter LSB while the first one does not. Note
that raw_seqcount_begin() can actually be implemented in terms of
raw_read_seqcount(), which will be done in a follow-up commit.
Then, group the seqcount_t write path functions, instead of injecting
unrelated seqcount_t latch functions between them, and order them as:
- raw_write_seqcount_begin()
- raw_write_seqcount_end()
- write_seqcount_begin_nested()
- write_seqcount_begin()
- write_seqcount_end()
- raw_write_seqcount_barrier()
- write_seqcount_invalidate()
which is the expected natural order. This also isolates the seqcount_t
latch functions into their own area, at the end of the sequence counters
section, and before jumping to the next one: sequential locks
(seqlock_t).
Do a similar grouping and reordering for seqlock_t "locking" readers vs.
the "conditionally locking or lockless" ones.
No implementation code was changed in any of the reordering above.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-5-a.darwish@linutronix.de
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The seqcount_t latch reader example at the raw_write_seqcount_latch()
kernel-doc comment ends the latch read section with a manual smp memory
barrier and sequence counter comparison.
This is technically correct, but it is suboptimal: read_seqcount_retry()
already contains the same logic of an smp memory barrier and sequence
counter comparison.
End the latch read critical section example with read_seqcount_retry().
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-4-a.darwish@linutronix.de
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Align the code samples and note sections inside kernel-doc comments with
tabs. This way they can be properly parsed and rendered by Sphinx. It
also makes the code samples easier to read from text editors.
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-3-a.darwish@linutronix.de
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Proper documentation for the design and usage of sequence counters and
sequential locks does not exist. Complete the seqlock.h documentation as
follows:
- Divide all documentation on a seqcount_t vs. seqlock_t basis. The
description for both mechanisms was intermingled, which is incorrect
since the usage constrains for each type are vastly different.
- Add an introductory paragraph describing the internal design of, and
rationale for, sequence counters.
- Document seqcount_t writer non-preemptibility requirement, which was
not previously documented anywhere, and provide a clear rationale.
- Provide template code for seqcount_t and seqlock_t initialization
and reader/writer critical sections.
- Recommend using seqlock_t by default. It implicitly handles the
serialization and non-preemptibility requirements of writers.
At seqlock.h:
- Remove references to brlocks as they've long been removed from the
kernel.
- Remove references to gcc-3.x since the kernel's minimum supported
gcc version is 4.9.
References: 0f6ed63b1707 ("no need to keep brlock macros anymore...")
References: 6ec4476ac825 ("Raise gcc version requirement to 4.9")
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200720155530.1173732-2-a.darwish@linutronix.de
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This patch breaks a header loop involving qspinlock_types.h.
The issue is that qspinlock_types.h includes atomic.h, which then
eventually includes kernel.h which could lead back to the original
file via spinlock_types.h.
As ATOMIC_INIT is now defined by linux/types.h, there is no longer
any need to include atomic.h from qspinlock_types.h. This also
allows the CONFIG_PARAVIRT hack to be removed since it was trying
to prevent exactly this loop.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lkml.kernel.org/r/20200729123316.GC7047@gondor.apana.org.au
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This patch moves ATOMIC_INIT from asm/atomic.h into linux/types.h.
This allows users of atomic_t to use ATOMIC_INIT without having to
include atomic.h as that way may lead to header loops.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Waiman Long <longman@redhat.com>
Link: https://lkml.kernel.org/r/20200729123105.GB7047@gondor.apana.org.au
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Some architectures may have special memory regions, within the given
memory range, which can't be used for the buffer in a kexec segment.
Implement weak arch_kexec_locate_mem_hole() definition which arch code
may override, to take care of special regions, while trying to locate
a memory hole.
Also, add the missing declarations for arch overridable functions and
and drop the __weak descriptors in the declarations to avoid non-weak
definitions from becoming weak.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Tested-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/159602273603.575379.17665852963340380839.stgit@hbathini
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This patch addresses warnings and errors from the kernel doc scripts for
the OpenCAPI driver.
It also makes minor tweaks to make the docs more consistent.
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200415012343.919255-3-alastair@d-silva.org
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Function declarations don't need externs, remove the existing ones
so they are consistent with newer code
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200415012343.919255-2-alastair@d-silva.org
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'arm/exynos', 'arm/smmu', 'ppc/pamu', 'x86/vt-d', 'x86/amd' and 'core' into next
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Introduce a mechanism that performs an handshake between the userspace
provider and kernel driver which verifies that the user supports all
required features in order to operate correctly.
The handshake verifies the needed functionality by comparing the reported
device caps and the provider caps. If the device reports a non-zero
capability the appropriate comp mask is required from the userspace
provider in order to allocate the context.
Link: https://lore.kernel.org/r/20200722140312.3651-4-galpress@amazon.com
Reviewed-by: Shadi Ammouri <sammouri@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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The device reports the minimum SQ size required for creation.
This patch queries the min SQ size and reports it back to the userspace
library.
Link: https://lore.kernel.org/r/20200722140312.3651-3-galpress@amazon.com
Reviewed-by: Firas JahJah <firasj@amazon.com>
Reviewed-by: Shadi Ammouri <sammouri@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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The device reports the maximum number of bytes to be written before
ringing the doorbell (zero means unlimited).
This patch queries the max batch size and reports it back to the userspace
library.
Link: https://lore.kernel.org/r/20200722140312.3651-2-galpress@amazon.com
Reviewed-by: Daniel Kranzdorf <dkkranzd@amazon.com>
Reviewed-by: Firas JahJah <firasj@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb into usb-next
Peter writes:
ENDIAN issue fix and one query controller role API is introduced.
* tag 'usb-ci-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/peter.chen/usb:
usb: chipidea: imx: get available runtime dr mode for wakeup setting
usb: chipidea: add query_available_role interface
Documentation: ABI: usb: chipidea: Update Li Jun's e-mail
usb: chipidea: udc: fix the ENDIAN issue
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RT tasks by default run at the highest capacity/performance level. When
uclamp is selected this default behavior is retained by enforcing the
requested uclamp.min (p->uclamp_req[UCLAMP_MIN]) of the RT tasks to be
uclamp_none(UCLAMP_MAX), which is SCHED_CAPACITY_SCALE; the maximum
value.
This is also referred to as 'the default boost value of RT tasks'.
See commit 1a00d999971c ("sched/uclamp: Set default clamps for RT tasks").
On battery powered devices, it is desired to control this default
(currently hardcoded) behavior at runtime to reduce energy consumed by
RT tasks.
For example, a mobile device manufacturer where big.LITTLE architecture
is dominant, the performance of the little cores varies across SoCs, and
on high end ones the big cores could be too power hungry.
Given the diversity of SoCs, the new knob allows manufactures to tune
the best performance/power for RT tasks for the particular hardware they
run on.
They could opt to further tune the value when the user selects
a different power saving mode or when the device is actively charging.
The runtime aspect of it further helps in creating a single kernel image
that can be run on multiple devices that require different tuning.
Keep in mind that a lot of RT tasks in the system are created by the
kernel. On Android for instance I can see over 50 RT tasks, only
a handful of which created by the Android framework.
To control the default behavior globally by system admins and device
integrator, introduce the new sysctl_sched_uclamp_util_min_rt_default
to change the default boost value of the RT tasks.
I anticipate this to be mostly in the form of modifying the init script
of a particular device.
To avoid polluting the fast path with unnecessary code, the approach
taken is to synchronously do the update by traversing all the existing
tasks in the system. This could race with a concurrent fork(), which is
dealt with by introducing sched_post_fork() function which will ensure
the racy fork will get the right update applied.
Tested on Juno-r2 in combination with the RT capacity awareness [1].
By default an RT task will go to the highest capacity CPU and run at the
maximum frequency, which is particularly energy inefficient on high end
mobile devices because the biggest core[s] are 'huge' and power hungry.
With this patch the RT task can be controlled to run anywhere by
default, and doesn't cause the frequency to be maximum all the time.
Yet any task that really needs to be boosted can easily escape this
default behavior by modifying its requested uclamp.min value
(p->uclamp_req[UCLAMP_MIN]) via sched_setattr() syscall.
[1] 804d402fb6f6: ("sched/rt: Make RT capacity-aware")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200716110347.19553-2-qais.yousef@arm.com
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Add passthru command handling capability for the NVMeOF target and
export passthru APIs which are used to integrate passthru
code with nvmet-core.
The new file passthru.c handles passthru cmd parsing and execution.
In the passthru mode, we create a block layer request from the nvmet
request and map the data on to the block layer request.
Admin commands and features are on an allow list as there are a number
of each that don't make too much sense with passthrough. We use an
allow list such that new commands can be considered before being blindly
passed through. In both cases, vendor specific commands are always
allowed.
We also reject reservation IO commands as the underlying device cannot
differentiate between multiple hosts behind a fabric.
Based-on-a-patch-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Drop the repeated word "a" in a comment.
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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git://anongit.freedesktop.org/drm/drm-misc into drm-fixes
* drm: fix possible use-after-free
* dbi: fix SPI Type 1 transfer
* drm_fb_helper: use memcpy_io on bochs' sparc64
* mcde: fix stability
* panel: fix display noise on auo,kd101n80-45na
* panel: delay HPD checks for boe_nv133fhm_n61
* bridge: drop connector check in nwl-dsi bridge
* bridge: set proper bridge type for adv7511
* of: fix a double free
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20200728110446.GA8076@linux-uq9g
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This patch implements the tmr_notify callback for tcmu. When the callback
is called, tcmu checks the list of aborted commands it received as
parameter:
- aborted commands in the qfull_queue are removed from the queue and
target_complete_command is called
- from the cmd_ids of aborted commands currently uncompleted in cmd ring
it creates a list of aborted cmd_ids.
Finally a TMR notification is written to cmd ring containing TMR type and
cmd_id list. If there is no space in ring, the TMR notification is queued
on a TMR specific queue.
The TMR specific queue 'tmr_queue' can be seen as a extension of the cmd
ring. At the end of each iexecution of tcmu_complete_commands() we check
whether tmr_queue contains TMRs and try to move them onto the ring. If
tmr_queue is not empty after that, we don't call run_qfull_queue() because
commands must not overtake TMRs.
This way we guarantee that cmd_ids in TMR notification received by
userspace either match an active, not yet completed command or are no
longer valid due to userspace having complete some cmd_ids meanwhile.
New commands that were assigned to an aborted cmd_id will always appear on
the cmd ring _after_ the TMR.
Link: https://lore.kernel.org/r/20200726153510.13077-8-bstroesser@ts.fujitsu.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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Target core is modified to call an optional backend callback function if a
TMR is received or commands are aborted implicitly after a PR command was
received. The backend function takes as parameters the se_dev, the type of
the TMR, and the list of aborted commands. If no commands were aborted, an
empty list is supplied.
Link: https://lore.kernel.org/r/20200726153510.13077-3-bstroesser@ts.fujitsu.com
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Bodo Stroesser <bstroesser@ts.fujitsu.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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