linux_dsm_epyc7002/arch/m68k/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

182 lines
4.4 KiB
C

/*
* include/asm-m68k/processor.h
*
* Copyright (C) 1995 Hamish Macdonald
*/
#ifndef __ASM_M68K_PROCESSOR_H
#define __ASM_M68K_PROCESSOR_H
/*
* Default implementation of macro that returns current
* instruction pointer ("program counter").
*/
#define current_text_addr() ({ __label__ _l; _l: &&_l;})
#include <linux/thread_info.h>
#include <asm/segment.h>
#include <asm/fpu.h>
#include <asm/ptrace.h>
static inline unsigned long rdusp(void)
{
#ifdef CONFIG_COLDFIRE_SW_A7
extern unsigned int sw_usp;
return sw_usp;
#else
register unsigned long usp __asm__("a0");
/* move %usp,%a0 */
__asm__ __volatile__(".word 0x4e68" : "=a" (usp));
return usp;
#endif
}
static inline void wrusp(unsigned long usp)
{
#ifdef CONFIG_COLDFIRE_SW_A7
extern unsigned int sw_usp;
sw_usp = usp;
#else
register unsigned long a0 __asm__("a0") = usp;
/* move %a0,%usp */
__asm__ __volatile__(".word 0x4e60" : : "a" (a0) );
#endif
}
/*
* User space process size: 3.75GB. This is hardcoded into a few places,
* so don't change it unless you know what you are doing.
*/
#ifdef CONFIG_MMU
#if defined(CONFIG_COLDFIRE)
#define TASK_SIZE (0xC0000000UL)
#elif defined(CONFIG_SUN3)
#define TASK_SIZE (0x0E000000UL)
#else
#define TASK_SIZE (0xF0000000UL)
#endif
#else
#define TASK_SIZE (0xFFFFFFFFUL)
#endif
#ifdef __KERNEL__
#define STACK_TOP TASK_SIZE
#define STACK_TOP_MAX STACK_TOP
#endif
/* This decides where the kernel will search for a free chunk of vm
* space during mmap's.
*/
#ifdef CONFIG_MMU
#if defined(CONFIG_COLDFIRE)
#define TASK_UNMAPPED_BASE 0x60000000UL
#elif defined(CONFIG_SUN3)
#define TASK_UNMAPPED_BASE 0x0A000000UL
#else
#define TASK_UNMAPPED_BASE 0xC0000000UL
#endif
#define TASK_UNMAPPED_ALIGN(addr, off) PAGE_ALIGN(addr)
#else
#define TASK_UNMAPPED_BASE 0
#endif
struct thread_struct {
unsigned long ksp; /* kernel stack pointer */
unsigned long usp; /* user stack pointer */
unsigned short sr; /* saved status register */
unsigned short fs; /* saved fs (sfc, dfc) */
unsigned long crp[2]; /* cpu root pointer */
unsigned long esp0; /* points to SR of stack frame */
unsigned long faddr; /* info about last fault */
int signo, code;
unsigned long fp[8*3];
unsigned long fpcntl[3]; /* fp control regs */
unsigned char fpstate[FPSTATESIZE]; /* floating point state */
};
#define INIT_THREAD { \
.ksp = sizeof(init_stack) + (unsigned long) init_stack, \
.sr = PS_S, \
.fs = __KERNEL_DS, \
}
/*
* ColdFire stack format sbould be 0x4 for an aligned usp (will always be
* true on thread creation). We need to set this explicitly.
*/
#ifdef CONFIG_COLDFIRE
#define setframeformat(_regs) do { (_regs)->format = 0x4; } while(0)
#else
#define setframeformat(_regs) do { } while (0)
#endif
#ifdef CONFIG_MMU
/*
* Do necessary setup to start up a newly executed thread.
*/
static inline void start_thread(struct pt_regs * regs, unsigned long pc,
unsigned long usp)
{
regs->pc = pc;
regs->sr &= ~0x2000;
setframeformat(regs);
wrusp(usp);
}
extern int handle_kernel_fault(struct pt_regs *regs);
#else
#define start_thread(_regs, _pc, _usp) \
do { \
(_regs)->pc = (_pc); \
setframeformat(_regs); \
if (current->mm) \
(_regs)->d5 = current->mm->start_data; \
(_regs)->sr &= ~0x2000; \
wrusp(_usp); \
} while(0)
static inline int handle_kernel_fault(struct pt_regs *regs)
{
/* Any fault in kernel is fatal on non-mmu */
return 0;
}
#endif
/* Forward declaration, a strange C thing */
struct task_struct;
/* Free all resources held by a thread. */
static inline void release_thread(struct task_struct *dead_task)
{
}
/*
* Free current thread data structures etc..
*/
static inline void exit_thread(void)
{
}
extern unsigned long thread_saved_pc(struct task_struct *tsk);
unsigned long get_wchan(struct task_struct *p);
#define KSTK_EIP(tsk) \
({ \
unsigned long eip = 0; \
if ((tsk)->thread.esp0 > PAGE_SIZE && \
(virt_addr_valid((tsk)->thread.esp0))) \
eip = ((struct pt_regs *) (tsk)->thread.esp0)->pc; \
eip; })
#define KSTK_ESP(tsk) ((tsk) == current ? rdusp() : (tsk)->thread.usp)
#define task_pt_regs(tsk) ((struct pt_regs *) ((tsk)->thread.esp0))
#define cpu_relax() barrier()
#define cpu_relax_lowlatency() cpu_relax()
#endif