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path: root/arch/mips/include/asm/spinlock.h
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2013-04-26MIPS: Remove redundant instructions from arch_spin_{,try}lock.David Daney1-4/+0
We were doing: SRL $r,$?,16 ANDI $r,$r,0xffff The logical right shift by 16 leaves the upper 16 bits clear, so the subsequent masking out of those bits is redundant, and can safely be removed. Signed-off-by: David Daney <david.daney@cavium.com> Cc: linux-mips@linux-mips.org Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-04-11MIPS: Remove further use of .subsectionRalf Baechle1-72/+44
7837314d141c661c70bc13c5050694413ecfe14a [MIPS: Get rid of branches to .subsections] removed most uses of .subsection] removed most uses of .subsection in inline assembler code. It left the instances in spinlock.h alone because we knew their use was in fairly small files where .subsection use was fine but of course this was a fragile assumption. LTO breaks this assumption resulting in build errors due to exceeded branch range, so remove further instances of .subsection. The two functions that still use .macro don't currently cause issues however this use is still fragile. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-02-01MIPS: Whitespace cleanup.Ralf Baechle1-2/+2
Having received another series of whitespace patches I decided to do this once and for all rather than dealing with this kind of patches trickling in forever. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-03-25MIPS: Microoptimize arch_{read,write}_lockRalf Baechle1-11/+11
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-02-27MIPS: Optimize spinlocks.David Daney1-75/+43
The current locking mechanism uses a ll/sc sequence to release a spinlock. This is slower than a wmb() followed by a store to unlock. The branching forward to .subsection 2 on sc failure slows down the contended case. So we get rid of that part too. Since we are now working on naturally aligned u16 values, we can get rid of a masking operation as the LHU already does the right thing. The ANDI are reversed for better scheduling on multi-issue CPUs On a 12 CPU 750MHz Octeon cn5750 this patch improves ipv4 UDP packet forwarding rates from 3.58*10^6 PPS to 3.99*10^6 PPS, or about 11%. Signed-off-by: David Daney <ddaney@caviumnetworks.com> To: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/937/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2010-02-27MIPS: New macro smp_mb__before_llsc.David Daney1-2/+2
Replace some instances of smp_llsc_mb() with a new macro smp_mb__before_llsc(). It is used before ll/sc sequences that are documented as needing write barrier semantics. The default implementation of smp_mb__before_llsc() is just smp_llsc_mb(), so there are no changes in semantics. Also simplify definition of smp_mb(), smp_rmb(), and smp_wmb() to be just barrier() in the non-SMP case. Signed-off-by: David Daney <ddaney@caviumnetworks.com> To: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/851/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-12-15locking: Convert raw_rwlock functions to arch_rwlockThomas Gleixner1-21/+21
Name space cleanup for rwlock functions. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
2009-12-15locking: Convert raw_rwlock to arch_rwlockThomas Gleixner1-6/+6
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 <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
2009-12-15locking: Convert __raw_spin* functions to arch_spin*Thomas Gleixner1-18/+18
Name space cleanup. No functional change. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
2009-12-15locking: Convert raw_spinlock to arch_spinlockThomas Gleixner1-5/+5
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 <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: linux-arch@vger.kernel.org
2009-04-03Allow rwlocks to re-enable interruptsRobin Holt1-0/+2
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 <ptesarik@suse.cz> Signed-off-by: Robin Holt <holt@sgi.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <linux-arch@vger.kernel.org> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-30MIPS: __raw_spin_lock() may spin forever on ticket wrap.David Daney1-4/+4
If the lock is not acquired and has to spin *and* the second attempt to acquire the lock fails, the delay time is not masked by the ticket range mask. If the ticket number wraps around to zero, the result is that the lock sampling delay is essentially infinite (due to casting -1 to an unsigned int). The fix: Always mask the difference between my_ticket and the current ticket value before calculating the delay. Signed-off-by: David Daney <ddaney@caviumnetworks.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2009-02-09x86: spinlocks: define dummy __raw_spin_is_contendedKyle McMartin1-0/+1
Architectures other than mips and x86 are not using ticket spinlocks. Therefore, the contention on the lock is meaningless, since there is nobody known to be waiting on it (arguably /fairly/ unfair locks). Dummy it out to return 0 on other architectures. Signed-off-by: Kyle McMartin <kyle@redhat.com> Acked-by: Ralf Baechle <ralf@linux-mips.org> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-15MIPS: Fix wrong branch target in new spin_lock code.Johannes Dickgreber1-1/+1
Signed-off-by: Johannes Dickgreber <tanzy@gmx.de> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-10-11MIPS: Rewrite spinlocks to ticket locks.Ralf Baechle1-71/+182
Based on patch by Chad Reese of Cavium Networks. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2008-10-11MIPS: Move headfiles to new location below arch/mips/includeRalf Baechle1-0/+376
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>