kernel.git/arch/arm/include/asm/spinlock.h, branch linux-3.2.y

ARM: 7955/1: spinlock: ensure we have a compiler barrier before sev

2014-04-01T23:58:50Z

commit 7c8746a9eb287642deaad0e7c2cdf482dce5e4be upstream. When unlocking a spinlock, we require the following, strictly ordered sequence of events: /* dmb */ /* dsb */ Whilst the code does indeed reflect this in terms of the architecture, the final + have been contracted into a single inline asm without a "memory" clobber, therefore the compiler is at liberty to reorder the unlock to the end of the above sequence. In such a case, a waiting CPU may be woken up before the lock has been unlocked, leading to extremely poor performance. This patch reworks the dsb_sev() function to make use of the dsb() macro and ensure ordering against the unlock. Reported-by: Mark Rutland Signed-off-by: Will Deacon Signed-off-by: Russell King [bwh: Backported to 3.2: 'ishst' variant is not used here] Signed-off-by: Ben Hutchings

ARM: 6939/1: fix missing 'cpu_relax()' declaration

2011-05-23T16:19:26Z

ARM build fails with the following symptom: CC arch/arm/kernel/asm-offsets.s In file included from include/linux/seqlock.h:29, from include/linux/time.h:8, from include/linux/timex.h:56, from include/linux/sched.h:57, from arch/arm/kernel/asm-offsets.c:13: include/linux/spinlock.h: In function 'spin_unlock_wait': include/linux/spinlock.h:360: error: implicit declaration of function 'cpu_relax' make[1]: *** [arch/arm/kernel/asm-offsets.s] Error 1 Fix it by including . Signed-off-by: Marc Zyngier Signed-off-by: Russell King

ARM: 6655/1: Correct WFE() in asm/spinlock.h for Thumb-2

2011-02-10T15:30:51Z

The content for ALT_SMP() in the definition of WFE() expands to 6 bytes (IT cc ; WFEcc.W), which breaks the assumptions of the fixup code, leading to lockups when the affected code gets run. This patch works around the problem by explicitly using an IT + WFEcc.N pair. Signed-off-by: Dave Martin Acked-by: Will Deacon Signed-off-by: Russell King

ARM: v6k: remove CPU_32v6K dependencies in asm/spinlock.h

2011-02-02T21:23:25Z

SMP requires at least the ARMv6K extensions to be present, so if we're running on SMP, the WFE and SEV instructions must be available. However, when we run on UP, the v6K extensions may not be available, and so we don't want WFE/SEV to be in the instruction stream. Use the SMP alternatives infrastructure to replace these instructions with NOPs if we build for SMP but run on UP. Tested-by: Tony Lindgren Tested-by: Sourav Poddar Tested-by: Will Deacon Signed-off-by: Russell King

ARM: 5897/1: spinlock: don't use deprecated barriers on ARMv7

2010-02-15T21:39:50Z

On ARMv7, the use of the cp15 operations for barriers is deprecated in favour of the isb, dsb, and dmb instructions. Change the locking functions to use the appropriate type of dsb for the architecture being built for. Signed-off-by: Rabin Vincent Signed-off-by: Russell King

locking: Convert raw_rwlock functions to arch_rwlock

2009-12-14T22:55:32Z

Name space cleanup for rwlock functions. No functional change. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Acked-by: David S. Miller Acked-by: Ingo Molnar Cc: linux-arch@vger.kernel.org

locking: Convert raw_rwlock to arch_rwlock

2009-12-14T22:55:32Z

Not strictly necessary for -rt as -rt does not have non sleeping rwlocks, but it's odd to not have a consistent naming convention. No functional change. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Acked-by: David S. Miller Acked-by: Ingo Molnar Cc: linux-arch@vger.kernel.org

locking: Convert __raw_spin* functions to arch_spin*

2009-12-14T22:55:32Z

Name space cleanup. No functional change. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Acked-by: David S. Miller Acked-by: Ingo Molnar Cc: linux-arch@vger.kernel.org

locking: Convert raw_spinlock to arch_spinlock

2009-12-14T22:55:32Z

The raw_spin* namespace was taken by lockdep for the architecture specific implementations. raw_spin_* would be the ideal name space for the spinlocks which are not converted to sleeping locks in preempt-rt. Linus suggested to convert the raw_ to arch_ locks and cleanup the name space instead of using an artifical name like core_spin, atomic_spin or whatever No functional change. Signed-off-by: Thomas Gleixner Acked-by: Peter Zijlstra Acked-by: David S. Miller Acked-by: Ingo Molnar Cc: linux-arch@vger.kernel.org

Allow rwlocks to re-enable interrupts

2009-04-03T02:05:11Z

Pass the original flags to rwlock arch-code, so that it can re-enable interrupts if implemented for that architecture. Initially, make __raw_read_lock_flags and __raw_write_lock_flags stubs which just do the same thing as non-flags variants. Signed-off-by: Petr Tesarik Signed-off-by: Robin Holt Acked-by: Peter Zijlstra Cc: Acked-by: Ingo Molnar Cc: "Luck, Tony" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds