linux/arch/mn10300/include/asm/processor.h
Davidlohr Bueso 3a6bfbc91d arch, locking: Ciao arch_mutex_cpu_relax()
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>
2014-07-17 12:32:47 +02:00

179 lines
4.3 KiB
C

/* MN10300 Processor specifics
*
* Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#ifndef _ASM_PROCESSOR_H
#define _ASM_PROCESSOR_H
#include <linux/threads.h>
#include <linux/thread_info.h>
#include <asm/page.h>
#include <asm/ptrace.h>
#include <asm/cpu-regs.h>
#include <asm/uaccess.h>
#include <asm/current.h>
/* Forward declaration, a strange C thing */
struct task_struct;
struct mm_struct;
/*
* Default implementation of macro that returns current
* instruction pointer ("program counter").
*/
#define current_text_addr() \
({ \
void *__pc; \
asm("mov pc,%0" : "=a"(__pc)); \
__pc; \
})
extern void get_mem_info(unsigned long *mem_base, unsigned long *mem_size);
extern void show_registers(struct pt_regs *regs);
/*
* CPU type and hardware bug flags. Kept separately for each CPU.
* Members of this structure are referenced in head.S, so think twice
* before touching them. [mj]
*/
struct mn10300_cpuinfo {
int type;
unsigned long loops_per_jiffy;
char hard_math;
};
extern struct mn10300_cpuinfo boot_cpu_data;
#ifdef CONFIG_SMP
#if CONFIG_NR_CPUS < 2 || CONFIG_NR_CPUS > 8
# error Sorry, NR_CPUS should be 2 to 8
#endif
extern struct mn10300_cpuinfo cpu_data[];
#define current_cpu_data cpu_data[smp_processor_id()]
#else /* CONFIG_SMP */
#define cpu_data &boot_cpu_data
#define current_cpu_data boot_cpu_data
#endif /* CONFIG_SMP */
extern void identify_cpu(struct mn10300_cpuinfo *);
extern void print_cpu_info(struct mn10300_cpuinfo *);
extern void dodgy_tsc(void);
#define cpu_relax() barrier()
#define cpu_relax_lowlatency() cpu_relax()
/*
* User space process size: 1.75GB (default).
*/
#define TASK_SIZE 0x70000000
/*
* Where to put the userspace stack by default
*/
#define STACK_TOP 0x70000000
#define STACK_TOP_MAX STACK_TOP
/* This decides where the kernel will search for a free chunk of vm
* space during mmap's.
*/
#define TASK_UNMAPPED_BASE 0x30000000
struct fpu_state_struct {
unsigned long fs[32]; /* fpu registers */
unsigned long fpcr; /* fpu control register */
};
struct thread_struct {
struct pt_regs *uregs; /* userspace register frame */
unsigned long pc; /* kernel PC */
unsigned long sp; /* kernel SP */
unsigned long a3; /* kernel FP */
unsigned long wchan;
unsigned long usp;
unsigned long fpu_flags;
#define THREAD_USING_FPU 0x00000001 /* T if this task is using the FPU */
#define THREAD_HAS_FPU 0x00000002 /* T if this task owns the FPU right now */
struct fpu_state_struct fpu_state;
};
#define INIT_THREAD \
{ \
.uregs = init_uregs, \
.pc = 0, \
.sp = 0, \
.a3 = 0, \
.wchan = 0, \
}
#define INIT_MMAP \
{ &init_mm, 0, 0, NULL, PAGE_SHARED, VM_READ | VM_WRITE | VM_EXEC, 1, \
NULL, NULL }
/*
* do necessary setup to start up a newly executed thread
*/
static inline void start_thread(struct pt_regs *regs,
unsigned long new_pc, unsigned long new_sp)
{
regs->epsw = EPSW_nSL | EPSW_IE | EPSW_IM;
regs->pc = new_pc;
regs->sp = new_sp;
}
/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);
/*
* Return saved PC of a blocked thread.
*/
extern unsigned long thread_saved_pc(struct task_struct *tsk);
unsigned long get_wchan(struct task_struct *p);
#define task_pt_regs(task) ((task)->thread.uregs)
#define KSTK_EIP(task) (task_pt_regs(task)->pc)
#define KSTK_ESP(task) (task_pt_regs(task)->sp)
#define KSTK_TOP(info) \
({ \
(unsigned long)(info) + THREAD_SIZE; \
})
#define ARCH_HAS_PREFETCH
#define ARCH_HAS_PREFETCHW
static inline void prefetch(const void *x)
{
#ifdef CONFIG_MN10300_CACHE_ENABLED
#ifdef CONFIG_MN10300_PROC_MN103E010
asm volatile ("nop; nop; dcpf (%0)" : : "r"(x));
#else
asm volatile ("dcpf (%0)" : : "r"(x));
#endif
#endif
}
static inline void prefetchw(const void *x)
{
#ifdef CONFIG_MN10300_CACHE_ENABLED
#ifdef CONFIG_MN10300_PROC_MN103E010
asm volatile ("nop; nop; dcpf (%0)" : : "r"(x));
#else
asm volatile ("dcpf (%0)" : : "r"(x));
#endif
#endif
}
#endif /* _ASM_PROCESSOR_H */