linux/lib/atomic64.c, branch v3.7-rc7

lib: reduce the use of module.h wherever possible

2012-03-07T20:04:04Z

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

lib: atomic64: Change the type of local lock to raw_spinlock_t

2011-09-14T11:14:11Z

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

locking, lib/atomic64: Annotate atomic64_lock::lock as raw

2011-09-13T09:12:22Z

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 Reviewed-by: Yong Zhang Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar

atomic: use

2011-07-26T23:49:47Z

This allows us to move duplicated code in (atomic_inc_not_zero() for now) to Signed-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

lib: Fix atomic64_add_unless return value convention

2010-03-01T19:38:46Z

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: <1267469749-11878-4-git-send-email-luca@luca-barbieri.com> Signed-off-by: H. Peter Anvin

lib: export generic atomic64_t functions

2009-07-30T02:10:35Z

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

lib: Provide generic atomic64_t implementation

2009-06-15T03:27:38Z

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