16 Jun, 2016
1 commit
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…relaxed,_acquire,_release}()
Now that all the architectures have implemented support for these new
atomic primitives add on the generic infrastructure to expose and use
it.Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
27 Jul, 2015
1 commit
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Implement atomic logic ops -- atomic_{or,xor,and}.
These will replace the atomic_{set,clear}_mask functions that are
available on some archs.Signed-off-by: Peter Zijlstra (Intel)
Signed-off-by: Thomas Gleixner
14 Aug, 2014
1 commit
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Rewrite generic atomic support to only require cmpxchg(), generate all
other primitives from that.Furthermore reduce the endless repetition for all these primitives to
a few CPP macros. This way we get more for less lines.Signed-off-by: Peter Zijlstra
Link: http://lkml.kernel.org/r/20140508135852.940119622@infradead.org
Cc: Arnd Bergmann
Cc: David Howells
Cc: Paul E. McKenney
Cc: David S. Miller
Cc: Linus Torvalds
Cc: linux-arch@vger.kernel.org
Signed-off-by: Ingo Molnar
21 Dec, 2012
1 commit
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The atomic64 library uses a handful of static spin locks to implement
atomic 64-bit operations on architectures without support for atomic
64-bit instructions.Unfortunately, the spinlocks are initialized in a pure initcall and that
is too late for the vfs namespace code which wants to use atomic64
operations before the initcall is run.This became a problem as of commit 8823c079ba71: "vfs: Add setns support
for the mount namespace".This leads to BUG messages such as:
BUG: spinlock bad magic on CPU#0, swapper/0/0
lock: atomic64_lock+0x240/0x400, .magic: 00000000, .owner: /-1, .owner_cpu: 0
do_raw_spin_lock+0x158/0x198
_raw_spin_lock_irqsave+0x4c/0x58
atomic64_add_return+0x30/0x5c
alloc_mnt_ns.clone.14+0x44/0xac
create_mnt_ns+0xc/0x54
mnt_init+0x120/0x1d4
vfs_caches_init+0xe0/0x10c
start_kernel+0x29c/0x300coming out early on during boot when spinlock debugging is enabled.
Fix this by initializing the spinlocks statically at compile time.
Reported-and-tested-by: Vaibhav Bedia
Tested-by: Tony Lindgren
Cc: Eric W. Biederman
Signed-off-by: Stephen Boyd
Signed-off-by: Linus Torvalds
08 Mar, 2012
1 commit
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For files only using THIS_MODULE and/or EXPORT_SYMBOL, map
them onto including export.h -- or if the file isn't even
using those, then just delete the include. Fix up any implicit
include dependencies that were being masked by module.h along
the way.Signed-off-by: Paul Gortmaker
14 Sep, 2011
1 commit
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There are still some leftovers of commit f59ca058
[locking, lib/atomic64: Annotate atomic64_lock::lock as raw][ tglx: Seems I picked the wrong version of that patch :( ]
Signed-off-by: Yong Zhang
Cc: Peter Zijlstra
Cc: Shan Hai
Cc: Stephen Rothwell
Link: http://lkml.kernel.org/r/20110914074924.GA16096@zhy
Signed-off-by: Thomas Gleixner
13 Sep, 2011
1 commit
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The spinlock protected atomic64 operations must be irq safe as they
are used in hard interrupt context and cannot be preempted on -rt:NIP [c068b218] rt_spin_lock_slowlock+0x78/0x3a8
LR [c068b1e0] rt_spin_lock_slowlock+0x40/0x3a8
Call Trace:
[eb459b90] [c068b1e0] rt_spin_lock_slowlock+0x40/0x3a8 (unreliable)
[eb459c20] [c068bdb0] rt_spin_lock+0x40/0x98
[eb459c40] [c03d2a14] atomic64_read+0x48/0x84
[eb459c60] [c001aaf4] perf_event_interrupt+0xec/0x28c
[eb459d10] [c0010138] performance_monitor_exception+0x7c/0x150
[eb459d30] [c0014170] ret_from_except_full+0x0/0x4cSo annotate it.
In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.Signed-off-by: Shan Hai
Reviewed-by: Yong Zhang
Signed-off-by: Thomas Gleixner
Signed-off-by: Ingo Molnar
27 Jul, 2011
1 commit
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This allows us to move duplicated code in
(atomic_inc_not_zero() for now) toSigned-off-by: Arun Sharma
Reviewed-by: Eric Dumazet
Cc: Ingo Molnar
Cc: David Miller
Cc: Eric Dumazet
Acked-by: Mike Frysinger
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Mar, 2010
1 commit
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atomic64_add_unless must return 1 if it perfomed the add and 0 otherwise.
The generic implementation did the opposite thing.Reported-by: H. Peter Anvin
Confirmed-by: Paul Mackerras
Signed-off-by: Luca Barbieri
LKML-Reference:
Signed-off-by: H. Peter Anvin
30 Jul, 2009
1 commit
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The generic atomic64_t implementation in lib/ did not export the functions
it defined, which means that modules that use atomic64_t would not link on
platforms (such as 32-bit powerpc). For example, trying to build a kernel
with CONFIG_NET_RDS on such a platform would fail with:ERROR: "atomic64_read" [net/rds/rds.ko] undefined!
ERROR: "atomic64_set" [net/rds/rds.ko] undefined!Fix this by exporting the atomic64_t functions to modules. (I export the
entire API even if it's not all currently used by in-tree modules to avoid
having to continue fixing this in dribs and drabs)Signed-off-by: Roland Dreier
Acked-by: Paul Mackerras
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Jun, 2009
1 commit
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Many processor architectures have no 64-bit atomic instructions, but
we need atomic64_t in order to support the perf_counter subsystem.This adds an implementation of 64-bit atomic operations using hashed
spinlocks to provide atomicity. For each atomic operation, the address
of the atomic64_t variable is hashed to an index into an array of 16
spinlocks. That spinlock is taken (with interrupts disabled) around the
operation, which can then be coded non-atomically within the lock.On UP, all the spinlock manipulation goes away and we simply disable
interrupts around each operation. In fact gcc eliminates the whole
atomic64_lock variable as well.Signed-off-by: Paul Mackerras
Signed-off-by: Benjamin Herrenschmidt
