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Commit 18cfd942 authored by Andreas Färber's avatar Andreas Färber Committed by Arnd Bergmann
Browse files

ARM: owl: smp: Drop bogus holding pen 



The S500 SoC can start secondary CPUs without busy-looping for pen_release,
so simplify the SMP code compared to the LeMaker kernel tree.

Fixes: 172067e0 ("ARM: owl: Implement CPU enable-method for S500")
Suggested-by: default avatarArnd Bergmann <arnd@arndb.de>
Cc: David Liu <liuwei@actions-semi.com>
Signed-off-by: default avatarAndreas Färber <afaerber@suse.de>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent eb382745

arch/arm/mach-actions/headsmp.S

+2 −18
Original line number Diff line number Diff line
@@ -2,6 +2,8 @@ 
 * Copyright 2012 Actions Semi Inc.

 * Author: Actions Semi, Inc.

 *

 * Copyright (c) 2017 Andreas Färber

 *

 * This program is free software; you can redistribute  it and/or modify it

 * under  the terms of  the GNU General  Public License as published by the

 * Free Software Foundation;  either version 2 of the  License, or (at your
@@ -46,23 +48,5 @@ ENTRY(owl_v7_invalidate_l1) 
ENDPROC(owl_v7_invalidate_l1)



ENTRY(owl_secondary_startup)

	mrc	p15, 0, r0, c0, c0, 5

	and	r0, r0, #0xf

	adr	r4, 1f

	ldmia	r4, {r5, r6}

	sub	r4, r4, r5

	add	r6, r6, r4

pen:

	ldr	r7, [r6]

	cmp	r7, r0

	bne	pen



	/*

	 * we've been released from the holding pen: secondary_stack

	 * should now contain the SVC stack for this core

	 */

	bl	owl_v7_invalidate_l1

	b	secondary_startup
 


1:	.long	.

	.long	pen_release

arch/arm/mach-actions/platsmp.c

+1 −28
Original line number Diff line number Diff line
@@ -41,26 +41,6 @@ static int ncores; 


static DEFINE_SPINLOCK(boot_lock);



static void write_pen_release(int val)

{

	pen_release = val;

	smp_wmb();

	__cpuc_flush_dcache_area((void *)&pen_release, sizeof(pen_release));

	outer_clean_range(__pa(&pen_release), __pa(&pen_release + 1));

}



static void s500_smp_secondary_init(unsigned int cpu)

{

	/*

	 * let the primary processor know we're out of the

	 * pen, then head off into the C entry point

	 */

	write_pen_release(-1);



	spin_lock(&boot_lock);

	spin_unlock(&boot_lock);

}



void owl_secondary_startup(void);



static int s500_wakeup_secondary(unsigned int cpu)
@@ -115,12 +95,6 @@ static int s500_smp_boot_secondary(unsigned int cpu, struct task_struct *idle) 


	spin_lock(&boot_lock);



	/*

	 * The secondary processor is waiting to be released from

	 * the holding pen - release it, then wait for it to flag

	 * that it has been released by resetting pen_release.

	 */

	write_pen_release(cpu_logical_map(cpu));

	smp_send_reschedule(cpu);



	timeout = jiffies + (1 * HZ);
@@ -134,7 +108,7 @@ static int s500_smp_boot_secondary(unsigned int cpu, struct task_struct *idle) 


	spin_unlock(&boot_lock);



	return pen_release != -1 ? -ENOSYS : 0;

	return 0;

}



static void __init s500_smp_prepare_cpus(unsigned int max_cpus)
@@ -192,7 +166,6 @@ static void __init s500_smp_prepare_cpus(unsigned int max_cpus) 


static const struct smp_operations s500_smp_ops __initconst = {

	.smp_prepare_cpus = s500_smp_prepare_cpus,

	.smp_secondary_init = s500_smp_secondary_init,

	.smp_boot_secondary = s500_smp_boot_secondary,

};

CPU_METHOD_OF_DECLARE(s500_smp, "actions,s500-smp", &s500_smp_ops);