From patchwork Thu Dec 13 18:00:57 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Russell King (Oracle)" X-Patchwork-Id: 10732961 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 59AD513BF for ; Mon, 17 Dec 2018 08:55:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4793229D69 for ; Mon, 17 Dec 2018 08:55:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3BAC029D8D; Mon, 17 Dec 2018 08:55:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Flag: YES X-Spam-Level: ** X-Spam-Status: Yes, score=2.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_LOW,RDNS_NONE,SORTED_RECIPS, SUSPICIOUS_RECIPS autolearn=no version=3.3.1 X-Spam-Report: * -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low * trust * [66.175.222.12 listed in list.dnswl.org] * -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * 2.5 SUSPICIOUS_RECIPS Similar addresses in recipient list * 2.5 SORTED_RECIPS Recipient list is sorted by address * -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature * 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily * valid * -1.0 MAILING_LIST_MULTI Multiple indicators imply a widely-seen list * manager * 0.8 RDNS_NONE Delivered to internal network by a host with no rDNS Received: from web01.groups.io (unknown [66.175.222.12]) (using TLSv1.2 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id B1B3A29D87 for ; Mon, 17 Dec 2018 08:55:15 +0000 (UTC) X-Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) by groups.io with SMTP; Thu, 13 Dec 2018 10:01:16 -0800 X-Received: from e0022681537dd.dyn.armlinux.org.uk ([fd8f:7570:feb6:1:222:68ff:fe15:37dd]:49260 helo=rmk-PC.armlinux.org.uk) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.90_1) (envelope-from ) id 1gXVIA-0003sQ-UZ; Thu, 13 Dec 2018 18:00:59 +0000 X-Received: from rmk by rmk-PC.armlinux.org.uk with local (Exim 4.82_1-5b7a7c0-XX) (envelope-from ) id 1gXVI9-000897-25; Thu, 13 Dec 2018 18:00:57 +0000 In-Reply-To: <20181213175952.GC26090@n2100.armlinux.org.uk> References: <20181213175952.GC26090@n2100.armlinux.org.uk> From: Russell King To: linux-arm-kernel@lists.infradead.org,linux-arm-msm@vger.kernel.org,linux-omap@vger.kernel.org,linux-oxnas@groups.io,linux-samsung-soc@vger.kernel.org,linux-soc@vger.kernel.org Cc: Patrice Chotard Subject: [linux-oxnas] [PATCH 4/9] ARM: sti: remove pen_release and boot_lock MIME-Version: 1.0 Message-Id: Date: Thu, 13 Dec 2018 18:00:57 +0000 Precedence: Bulk List-Unsubscribe: Sender: linux-oxnas@groups.io List-Id: Mailing-List: list linux-oxnas@groups.io; contact linux-oxnas+owner@groups.io Delivered-To: mailing list linux-oxnas@groups.io Reply-To: linux-oxnas@groups.io,rmk+kernel@armlinux.org.uk Content-Disposition: inline DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=groups.io; q=dns/txt; s=20140610; t=1545036915; bh=rmnX/RlQOSkpmywp+L+HGdyuh/m++3eKi2bZGw88Zj0=; h=Cc:Content-Type:Date:From:Reply-To:Subject:To; b=c5L8ppOGiirfJehIa87W1CX6F4peeq5NQAKAcuvpGZWZZO3RD2vjxmpoA4yLjE3rW6+ X+Rx+GLQF+pBTG6RJOOQzONRHFHTTL6rjHruf3hrtXD5JTO2eJy1twsZtnqaGkUm2eEn+ h6t3zhSoX8lnxQ5BfHH+BQZrCNfexwzCDIQ= X-Virus-Scanned: ClamAV using ClamSMTP The pen_release implementation was created for Versatile platforms to work around boot loaders that did not differentiate between the various different secondary CPUs on this ARM development platform. This should not be true of modern platforms where we send IPIs to specific CPUs to wake them up. Remove the pen_release stuff from SoCs that make use of the per-CPU IPI mechanism. The boot_lock is something that was required for ARM development platforms to ensure that the delay calibration worked properly. This is not necessary for modern platforms that have better bus bandwidth and do not need to calibrate the delay loop for secondary cores. Remove the boot_lock entirely. Signed-off-by: Russell King --- arch/arm/mach-sti/Makefile | 2 +- arch/arm/mach-sti/headsmp.S | 43 ------------------------------- arch/arm/mach-sti/platsmp.c | 62 ++------------------------------------------- 3 files changed, 3 insertions(+), 104 deletions(-) delete mode 100644 arch/arm/mach-sti/headsmp.S diff --git a/arch/arm/mach-sti/Makefile b/arch/arm/mach-sti/Makefile index acb330916333..f85ff059cfba 100644 --- a/arch/arm/mach-sti/Makefile +++ b/arch/arm/mach-sti/Makefile @@ -1,2 +1,2 @@ -obj-$(CONFIG_SMP) += platsmp.o headsmp.o +obj-$(CONFIG_SMP) += platsmp.o obj-$(CONFIG_ARCH_STI) += board-dt.o diff --git a/arch/arm/mach-sti/headsmp.S b/arch/arm/mach-sti/headsmp.S deleted file mode 100644 index e0ad451700d5..000000000000 --- a/arch/arm/mach-sti/headsmp.S +++ /dev/null @@ -1,43 +0,0 @@ -/* - * arch/arm/mach-sti/headsmp.S - * - * Copyright (C) 2013 STMicroelectronics (R&D) Limited. - * http://www.st.com - * - * Cloned from linux/arch/arm/mach-vexpress/headsmp.S - * - * Copyright (c) 2003 ARM Limited - * All Rights Reserved - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ -#include -#include - -/* - * ST specific entry point for secondary CPUs. This provides - * a "holding pen" into which all secondary cores are held until we're - * ready for them to initialise. - */ -ENTRY(sti_secondary_startup) - mrc p15, 0, r0, c0, c0, 5 - and r0, r0, #15 - 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 - */ - b secondary_startup -ENDPROC(sti_secondary_startup) - -1: .long . - .long pen_release diff --git a/arch/arm/mach-sti/platsmp.c b/arch/arm/mach-sti/platsmp.c index 231f19e17436..21668501c9bb 100644 --- a/arch/arm/mach-sti/platsmp.c +++ b/arch/arm/mach-sti/platsmp.c @@ -28,72 +28,15 @@ #include "smp.h" -static void write_pen_release(int val) -{ - pen_release = val; - smp_wmb(); - sync_cache_w(&pen_release); -} - -static DEFINE_SPINLOCK(boot_lock); - -static void sti_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); - - /* - * Synchronise with the boot thread. - */ - spin_lock(&boot_lock); - spin_unlock(&boot_lock); -} - static int sti_boot_secondary(unsigned int cpu, struct task_struct *idle) { - unsigned long timeout; - - /* - * set synchronisation state between this boot processor - * and the secondary one - */ - 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. - * - * Note that "pen_release" is the hardware CPU ID, whereas - * "cpu" is Linux's internal ID. - */ - write_pen_release(cpu_logical_map(cpu)); - /* * Send the secondary CPU a soft interrupt, thereby causing * it to jump to the secondary entrypoint. */ arch_send_wakeup_ipi_mask(cpumask_of(cpu)); - timeout = jiffies + (1 * HZ); - while (time_before(jiffies, timeout)) { - smp_rmb(); - if (pen_release == -1) - break; - - udelay(10); - } - - /* - * now the secondary core is starting up let it run its - * calibrations, then wait for it to finish - */ - spin_unlock(&boot_lock); - - return pen_release != -1 ? -ENOSYS : 0; + return 0; } static void __init sti_smp_prepare_cpus(unsigned int max_cpus) @@ -103,7 +46,7 @@ static void __init sti_smp_prepare_cpus(unsigned int max_cpus) u32 __iomem *cpu_strt_ptr; u32 release_phys; int cpu; - unsigned long entry_pa = __pa_symbol(sti_secondary_startup); + unsigned long entry_pa = __pa_symbol(secondary_startup); np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu"); @@ -158,6 +101,5 @@ static void __init sti_smp_prepare_cpus(unsigned int max_cpus) const struct smp_operations sti_smp_ops __initconst = { .smp_prepare_cpus = sti_smp_prepare_cpus, - .smp_secondary_init = sti_secondary_init, .smp_boot_secondary = sti_boot_secondary, };