From 18cfd9429d8a82c49add8f3ca9d366599bfcac45 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Andreas=20F=C3=A4rber?= Date: Sat, 1 Jul 2017 23:29:30 +0200 Subject: [PATCH] ARM: owl: smp: Drop bogus holding pen MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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: 172067e0bc87 ("ARM: owl: Implement CPU enable-method for S500") Suggested-by: Arnd Bergmann Cc: David Liu Signed-off-by: Andreas Färber Signed-off-by: Arnd Bergmann --- arch/arm/mach-actions/headsmp.S | 20 ++------------------ arch/arm/mach-actions/platsmp.c | 29 +---------------------------- 2 files changed, 3 insertions(+), 46 deletions(-) diff --git a/arch/arm/mach-actions/headsmp.S b/arch/arm/mach-actions/headsmp.S index dc4832f..65f53bd 100644 --- a/arch/arm/mach-actions/headsmp.S +++ b/arch/arm/mach-actions/headsmp.S @@ -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 diff --git a/arch/arm/mach-actions/platsmp.c b/arch/arm/mach-actions/platsmp.c index b4806ce..12a9e33 100644 --- a/arch/arm/mach-actions/platsmp.c +++ b/arch/arm/mach-actions/platsmp.c @@ -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); -- 2.7.4