Commit 4e287e65 authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Michael Ellerman
Browse files

powerpc: use spin loop primitives in some functions 



Use the different spin loop primitives in some simple powerpc
spin loops, including those which will spin as a common case.

This will help to test the spin loop primitives before more
conversions are done.

Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
[mpe: Add some includes of <linux/processor.h>]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent ede8e2bb

arch/powerpc/include/asm/delay.h

+12 −4
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#define _ASM_POWERPC_DELAY_H

#ifdef __KERNEL__



#include <linux/processor.h>

#include <asm/time.h>



/*
@@ -58,11 +59,18 @@ extern void udelay(unsigned long usecs); 
	typeof(condition) __ret;                                               \

	unsigned long __loops = tb_ticks_per_usec * timeout;                   \

	unsigned long __start = get_tbl();                                     \

	while (!(__ret = (condition)) && (tb_ticks_since(__start) <= __loops)) \

		if (delay)                                                     \

                                                                               \

	if (delay) {                                                           \

		while (!(__ret = (condition)) &&                               \

				(tb_ticks_since(__start) <= __loops))          \

			udelay(delay);                                         \

		else                                                           \

			cpu_relax();                                           \

	} else {                                                               \

		spin_begin();                                                  \

		while (!(__ret = (condition)) &&                               \

				(tb_ticks_since(__start) <= __loops))          \

			spin_cpu_relax();                                      \

		spin_end();                                                    \

	}                                                                      \

	if (!__ret)                                                            \

		__ret = (condition);                                           \

	__ret;		                                                       \

arch/powerpc/kernel/smp.c

+2 −2
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#include <linux/notifier.h>

#include <linux/topology.h>

#include <linux/profile.h>

#include <linux/processor.h>



#include <asm/ptrace.h>

#include <linux/atomic.h>
@@ -767,8 +768,7 @@ int __cpu_up(unsigned int cpu, struct task_struct *tidle) 
		smp_ops->give_timebase();



	/* Wait until cpu puts itself in the online & active maps */

	while (!cpu_online(cpu))

		cpu_relax();

	spin_until_cond(cpu_online(cpu));



	return 0;

}

arch/powerpc/kernel/time.c

+5 −3
Original line number Diff line number Diff line
@@ -59,10 +59,10 @@ 
#include <linux/suspend.h>

#include <linux/rtc.h>

#include <linux/sched/cputime.h>

#include <linux/processor.h>

#include <asm/trace.h>



#include <asm/io.h>

#include <asm/processor.h>

#include <asm/nvram.h>

#include <asm/cache.h>

#include <asm/machdep.h>
@@ -442,6 +442,7 @@ void __delay(unsigned long loops) 
	unsigned long start;

	int diff;



	spin_begin();

	if (__USE_RTC()) {

		start = get_rtcl();

		do {
@@ -449,13 +450,14 @@ void __delay(unsigned long loops) 
			diff = get_rtcl() - start;

			if (diff < 0)

				diff += 1000000000;

			spin_cpu_relax();

		} while (diff < loops);

	} else {

		start = get_tbl();

		while (get_tbl() - start < loops)

			HMT_low();

		HMT_medium();

			spin_cpu_relax();

	}

	spin_end();

}

EXPORT_SYMBOL(__delay);

arch/powerpc/mm/hash_native_64.c

+4 −1
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/spinlock.h>

#include <linux/bitops.h>

#include <linux/of.h>

#include <linux/processor.h>

#include <linux/threads.h>

#include <linux/smp.h>
@@ -184,8 +185,10 @@ static inline void native_lock_hpte(struct hash_pte *hptep) 
	while (1) {

		if (!test_and_set_bit_lock(HPTE_LOCK_BIT, word))

			break;

		spin_begin();

		while(test_bit(HPTE_LOCK_BIT, word))

			cpu_relax();

			spin_cpu_relax();

		spin_end();

	}

}

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