Based on 1 normalized pattern(s):
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extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Allison Randal <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
As a step towards unifying the atomic/atomic64/atomic_long APIs, this
patch converts the generic implementation of atomic64_add_unless() into
a generic implementation of atomic64_fetch_add_unless().
A wrapper in <linux/atomic.h> will build atomic_add_unless() atop of
this, provided it is given a preprocessor definition.
No functional change is intended as a result of this patch.
Signed-off-by: Mark Rutland <[email protected]>
Reviewed-by: Will Deacon <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
Some of the atomics return a status value, which is a boolean value
describing whether the operation was performed. To make it clear that
this is a boolean value, let's update the common fallbacks to return
bool, fixing up the return values and comments likewise.
At the same time, let's simplify the description of the operations in
their respective comments.
The instrumented atomics and generic atomic64 implementation are updated
accordingly.
Note that atomic64_dec_if_positive() doesn't follow the usual test op
pattern, and returns the would-be decremented value. This is not
changed.
Signed-off-by: Mark Rutland <[email protected]>
Reviewed-by: Will Deacon <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Cc: Boqun Feng <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: https://lore.kernel.org/lkml/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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) <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
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 8823c079ba: "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: <none>/-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/0x300
coming 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 <[email protected]>
Tested-by: Tony Lindgren <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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 <[email protected]>
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+0x0/0x4c
So 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 <[email protected]>
Reviewed-by: Yong Zhang <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
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 <[email protected]>
Confirmed-by: Paul Mackerras <[email protected]>
Signed-off-by: Luca Barbieri <[email protected]>
LKML-Reference: <[email protected]>
Signed-off-by: H. Peter Anvin <[email protected]>
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 <[email protected]>
Acked-by: Paul Mackerras <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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 <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>
Mark Rutland