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3a6bfbc91d
The arch_mutex_cpu_relax() function, introduced by 34b133f, is
hacky and ugly. It was added a few years ago to address the fact
that common cpu_relax() calls include yielding on s390, and thus
impact the optimistic spinning functionality of mutexes. Nowadays
we use this function well beyond mutexes: rwsem, qrwlock, mcs and
lockref. Since the macro that defines the call is in the mutex header,
any users must include mutex.h and the naming is misleading as well.
This patch (i) renames the call to cpu_relax_lowlatency ("relax, but
only if you can do it with very low latency") and (ii) defines it in
each arch's asm/processor.h local header, just like for regular cpu_relax
functions. On all archs, except s390, cpu_relax_lowlatency is simply cpu_relax,
and thus we can take it out of mutex.h. While this can seem redundant,
I believe it is a good choice as it allows us to move out arch specific
logic from generic locking primitives and enables future(?) archs to
transparently define it, similarly to System Z.
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Blanchard <anton@samba.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Bharat Bhushan <r65777@freescale.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Chen Liqin <liqin.linux@gmail.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Howells <dhowells@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Cc: Dominik Dingel <dingel@linux.vnet.ibm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Joe Perches <joe@perches.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Joseph Myers <joseph@codesourcery.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Salter <msalter@redhat.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Qais Yousef <qais.yousef@imgtec.com>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Rafael Wysocki <rafael.j.wysocki@intel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steven Miao <realmz6@gmail.com>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Stratos Karafotis <stratosk@semaphore.gr>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vasily Kulikov <segoon@openwall.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Cc: Waiman Long <Waiman.Long@hp.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: adi-buildroot-devel@lists.sourceforge.net
Cc: linux390@de.ibm.com
Cc: linux-alpha@vger.kernel.org
Cc: linux-am33-list@redhat.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-cris-kernel@axis.com
Cc: linux-hexagon@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linux@lists.openrisc.net
Cc: linux-m32r-ja@ml.linux-m32r.org
Cc: linux-m32r@ml.linux-m32r.org
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-metag@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: linux-parisc@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: linux-sh@vger.kernel.org
Cc: linux-xtensa@linux-xtensa.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/1404079773.2619.4.camel@buesod1.americas.hpqcorp.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
106 lines
2.5 KiB
C
106 lines
2.5 KiB
C
#ifndef _ASM_SCORE_PROCESSOR_H
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#define _ASM_SCORE_PROCESSOR_H
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#include <linux/cpumask.h>
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#include <linux/threads.h>
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#include <asm/segment.h>
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struct task_struct;
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/*
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* System setup and hardware flags..
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*/
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extern void (*cpu_wait)(void);
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extern unsigned long thread_saved_pc(struct task_struct *tsk);
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extern void start_thread(struct pt_regs *regs,
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unsigned long pc, unsigned long sp);
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extern unsigned long get_wchan(struct task_struct *p);
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/*
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* Return current * instruction pointer ("program counter").
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*/
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#define current_text_addr() ({ __label__ _l; _l: &&_l; })
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#define cpu_relax() barrier()
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#define cpu_relax_lowlatency() cpu_relax()
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#define release_thread(thread) do {} while (0)
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/*
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* User space process size: 2GB. This is hardcoded into a few places,
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* so don't change it unless you know what you are doing.
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*/
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#define TASK_SIZE 0x7fff8000UL
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/*
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* This decides where the kernel will search for a free chunk of vm
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* space during mmap's.
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*/
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#define TASK_UNMAPPED_BASE ((TASK_SIZE / 3) & ~(PAGE_SIZE))
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#ifdef __KERNEL__
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#define STACK_TOP TASK_SIZE
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#define STACK_TOP_MAX TASK_SIZE
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#endif
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/*
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* If you change thread_struct remember to change the #defines below too!
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*/
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struct thread_struct {
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unsigned long reg0, reg2, reg3;
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unsigned long reg12, reg13, reg14, reg15, reg16;
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unsigned long reg17, reg18, reg19, reg20, reg21;
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unsigned long cp0_psr;
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unsigned long cp0_ema; /* Last user fault */
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unsigned long cp0_badvaddr; /* Last user fault */
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unsigned long cp0_baduaddr; /* Last kernel fault accessing USEG */
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unsigned long error_code;
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unsigned long trap_no;
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unsigned long mflags;
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unsigned long reg29;
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unsigned long single_step;
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unsigned long ss_nextcnt;
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unsigned long insn1_type;
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unsigned long addr1;
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unsigned long insn1;
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unsigned long insn2_type;
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unsigned long addr2;
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unsigned long insn2;
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mm_segment_t current_ds;
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};
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#define INIT_THREAD { \
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.reg0 = 0, \
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.reg2 = 0, \
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.reg3 = 0, \
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.reg12 = 0, \
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.reg13 = 0, \
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.reg14 = 0, \
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.reg15 = 0, \
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.reg16 = 0, \
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.reg17 = 0, \
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.reg18 = 0, \
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.reg19 = 0, \
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.reg20 = 0, \
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.reg21 = 0, \
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.cp0_psr = 0, \
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.error_code = 0, \
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.trap_no = 0, \
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}
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#define kstk_tos(tsk) \
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((unsigned long)task_stack_page(tsk) + THREAD_SIZE - 32)
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#define task_pt_regs(tsk) ((struct pt_regs *)kstk_tos(tsk) - 1)
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#define KSTK_EIP(tsk) (task_pt_regs(tsk)->cp0_epc)
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#define KSTK_ESP(tsk) (task_pt_regs(tsk)->regs[29])
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#endif /* _ASM_SCORE_PROCESSOR_H */
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