kernel/linux.git/arch/arc/include/asm/spinlock.h, branch v5.0.3

locking/arch: Remove dummy arch_{read,spin,write}_lock_flags() implementations

2017-10-10T09:50:19+00:00

The arch_{read,spin,write}_lock_flags() macros are simply mapped to the non-flags versions by the majority of architectures, so do this in core code and remove the dummy implementations. Also remove the implementation in spinlock_up.h, since all callers of do_raw_spin_lock_flags() call local_irq_save(flags) anyway. Signed-off-by: Will Deacon Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507055129-12300-4-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar

locking/arch: Remove dummy arch_{read,spin,write}_relax() implementations

2017-10-10T09:50:18+00:00

arch_{read,spin,write}_relax() are defined as cpu_relax() by the core code, so architectures that can't do better (i.e. most of them) don't need to bother with the dummy definitions. Signed-off-by: Will Deacon Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507055129-12300-3-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar

locking/core: Remove {read,spin,write}_can_lock()

2017-10-10T09:50:18+00:00

Outside of the locking code itself, {read,spin,write}_can_lock() have no users in tree. Apparmor (the last remaining user of write_can_lock()) got moved over to lockdep by the previous patch. This patch removes the use of {read,spin,write}_can_lock() from the BUILD_LOCK_OPS macro, deferring to the trylock operation for testing the lock status, and subsequently removes the unused macros altogether. They aren't guaranteed to work in a concurrent environment and can give incorrect results in the case of qrwlock. Signed-off-by: Will Deacon Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/1507055129-12300-2-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar

Merge tag 'arc-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

2017-09-08T23:02:18+00:00

Pull ARC updates from Vineet Gupta: - Support for HSDK board hosting a Quad core HS38x4 based SoC running @1GHz (and some prerrquisite changes such as ability to scoot the kernel code/data from start of memory map etc) - Quite a few updates for EZChip (Mellanox) platform - Fixes to fault/exception printing * tag 'arc-4.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (26 commits) ARC: Re-enable MMU upon Machine Check exception ARC: Show fault information passed to show_kernel_fault_diag() ARC: [plat-hsdk] initial port for HSDK board ARC: mm: Decouple RAM base address from kernel link address ARCv2: IOC: Tighten up the contraints (specifically base / size alignment) ARC: [plat-axs103] refactor the DT fudging code ARC: [plat-axs103] use clk driver #2: Add core pll node to DT to manage cpu clk ARC: [plat-axs103] use clk driver #1: Get rid of platform specific cpu clk setting ARCv2: SLC: provide a line based flush routine for debugging ARC: Hardcode ARCH_DMA_MINALIGN to max line length we may have ARC: [plat-eznps] handle extra aux regs #2: kernel/entry exit ARC: [plat-eznps] handle extra aux regs #1: save/restore on context switch ARC: [plat-eznps] avoid toggling of DPC register ARC: [plat-eznps] Update the init sequence of aux regs per cpu. ARC: [plat-eznps] new command line argument for HW scheduler at MTM ARC: set boot print log level to PR_INFO ARC: [plat-eznps] Handle user memory error same in simulation and silicon ARC: [plat-eznps] use schd.wft instruction instead of sleep at idle task ARC: create cpu specific version of arch_cpu_idle() ARC: [plat-eznps] spinlock aware for MTM ...

ARC: [plat-eznps] spinlock aware for MTM

2017-08-28T22:17:36+00:00

This way when we execute "ex" during trying to hold lock we can switch to other HW thread and utilize the core intead of just spinning on a lock. We noticed about 10% improvement of execution time with hackbench test. Signed-off-by: Noam Camus Signed-off-by: Vineet Gupta

ARC: spinlock: Document the EX based spin_unlock

2017-08-28T22:17:36+00:00

Signed-off-by: Vineet Gupta

arch: Remove spin_unlock_wait() arch-specific definitions

2017-08-17T15:08:59+00:00

There is no agreed-upon definition of spin_unlock_wait()'s semantics, and it appears that all callers could do just as well with a lock/unlock pair. This commit therefore removes the underlying arch-specific arch_spin_unlock_wait() for all architectures providing them. Signed-off-by: Paul E. McKenney Cc: Cc: Peter Zijlstra Cc: Alan Stern Cc: Andrea Parri Cc: Linus Torvalds Acked-by: Will Deacon Acked-by: Boqun Feng

locking/spinlock, arch: Update and fix spin_unlock_wait() implementations

2016-06-14T09:55:15+00:00

This patch updates/fixes all spin_unlock_wait() implementations. The update is in semantics; where it previously was only a control dependency, we now upgrade to a full load-acquire to match the store-release from the spin_unlock() we waited on. This ensures that when spin_unlock_wait() returns, we're guaranteed to observe the full critical section we waited on. This fixes a number of spin_unlock_wait() users that (not unreasonably) rely on this. I also fixed a number of ticket lock versions to only wait on the current lock holder, instead of for a full unlock, as this is sufficient. Furthermore; again for ticket locks; I added an smp_rmb() in between the initial ticket load and the spin loop testing the current value because I could not convince myself the address dependency is sufficient, esp. if the loads are of different sizes. I'm more than happy to remove this smp_rmb() again if people are certain the address dependency does indeed work as expected. Note: PPC32 will be fixed independently Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: chris@zankel.net Cc: cmetcalf@mellanox.com Cc: davem@davemloft.net Cc: dhowells@redhat.com Cc: james.hogan@imgtec.com Cc: jejb@parisc-linux.org Cc: linux@armlinux.org.uk Cc: mpe@ellerman.id.au Cc: ralf@linux-mips.org Cc: realmz6@gmail.com Cc: rkuo@codeaurora.org Cc: rth@twiddle.net Cc: schwidefsky@de.ibm.com Cc: tony.luck@intel.com Cc: vgupta@synopsys.com Cc: ysato@users.sourceforge.jp Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar

Revert "ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff"

2016-06-02T05:29:23+00:00

This reverts commit e78fdfef84be13a5c2b8276e12203cdf24778596. The issue was fixed in hardware in HS2.1C release and there are no known external users of affected RTL so revert the whole delayed retry series ! Signed-off-by: Vineet Gupta

Revert "ARCv2: spinlock/rwlock: Reset retry delay when starting a new spin-wait cycle"

2016-06-02T05:29:23+00:00

This reverts commit b89aa12c177477e34caa722818536fb5d0bffd76. The issue was fixed in hardware in HS2.1C release and there are no known external users of affected RTL so revert the whole delayed retry series ! Signed-off-by: Vineet Gupta