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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: 172067e0bc ("ARM: owl: Implement CPU enable-method for S500")
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Cc: David Liu <liuwei@actions-semi.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
hifive-unleashed-5.1
Andreas Färber 2017-07-01 23:29:30 +02:00 committed by Arnd Bergmann
parent eb3827457a
commit 18cfd9429d
2 changed files with 3 additions and 46 deletions
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20
arch/arm/mach-actions/headsmp.S
View File

@ -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

29
arch/arm/mach-actions/platsmp.c
View File

@ -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);