[stable/v4.2.y] ARM: ux500: simplify secondary CPU boot

Message ID	1445554568-4871-1-git-send-email-khilman@kernel.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org> From: Kevin Hilman <khilman@kernel.org> To: stable@vger.kernel.org Subject: [PATCH stable/v4.2.y] ARM: ux500: simplify secondary CPU boot Date: Thu, 22 Oct 2015 15:56:08 -0700 Message-Id: <1445554568-4871-1-git-send-email-khilman@kernel.org> MIME-Version: 1.0 Precedence: list Cc: Olof Johansson <olof@lixom.net>, Linus Walleij <linus.walleij@linaro.org>, Kevin Hilman <khilman@linaro.org>, tyler.baker@linaro.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org

diff --git a/arch/arm/mach-ux500/Makefile b/arch/arm/mach-ux500/Makefile index 4418a5078833..c8643ac5db71 100644 --- a/arch/arm/mach-ux500/Makefile +++ b/arch/arm/mach-ux500/Makefile @@ -7,7 +7,7 @@ obj-$(CONFIG_CACHE_L2X0) += cache-l2x0.o obj-$(CONFIG_UX500_SOC_DB8500) += cpu-db8500.o obj-$(CONFIG_MACH_MOP500) += board-mop500-regulators.o \ board-mop500-audio.o -obj-$(CONFIG_SMP) += platsmp.o headsmp.o +obj-$(CONFIG_SMP) += platsmp.o obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o obj-$(CONFIG_PM_GENERIC_DOMAINS) += pm_domains.o diff --git a/arch/arm/mach-ux500/cpu-db8500.c b/arch/arm/mach-ux500/cpu-db8500.c index 16913800bbf9..ba708ce08616 100644 --- a/arch/arm/mach-ux500/cpu-db8500.c +++ b/arch/arm/mach-ux500/cpu-db8500.c @@ -154,7 +154,6 @@ static const char * stericsson_dt_platform_compat[] = { }; DT_MACHINE_START(U8500_DT, "ST-Ericsson Ux5x0 platform (Device Tree Support)") - .smp = smp_ops(ux500_smp_ops), .map_io = u8500_map_io, .init_irq = ux500_init_irq, /* we re-use nomadik timer here */ diff --git a/arch/arm/mach-ux500/headsmp.S b/arch/arm/mach-ux500/headsmp.S deleted file mode 100644 index 9cdea049485d..000000000000 --- a/arch/arm/mach-ux500/headsmp.S +++ /dev/null @@ -1,37 +0,0 @@ -/* - * Copyright (c) 2009 ST-Ericsson - * This file is based ARM Realview platform - * 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 <linux/linkage.h> -#include <linux/init.h> - -/* - * U8500 specific entry point for secondary CPUs. - */ -ENTRY(u8500_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(u8500_secondary_startup) - - .align 2 -1: .long . - .long pen_release diff --git a/arch/arm/mach-ux500/platsmp.c b/arch/arm/mach-ux500/platsmp.c index 62b1de922bd8..70766b963758 100644 --- a/arch/arm/mach-ux500/platsmp.c +++ b/arch/arm/mach-ux500/platsmp.c @@ -28,135 +28,81 @@ #include "db8500-regs.h" #include "id.h" -static void __iomem *scu_base; -static void __iomem *backupram; - -/* This is called from headsmp.S to wakeup the secondary core */ -extern void u8500_secondary_startup(void); - -/* - * Write pen_release in a way that is guaranteed to be visible to all - * observers, irrespective of whether they're taking part in coherency - * or not. This is necessary for the hotplug code to work reliably. - */ -static void write_pen_release(int val) -{ - pen_release = val; - smp_wmb(); - sync_cache_w(&pen_release); -} - -static DEFINE_SPINLOCK(boot_lock); - -static void ux500_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); -} +/* Magic triggers in backup RAM */ +#define UX500_CPU1_JUMPADDR_OFFSET 0x1FF4 +#define UX500_CPU1_WAKEMAGIC_OFFSET 0x1FF0 -static int ux500_boot_secondary(unsigned int cpu, struct task_struct *idle) +static void wakeup_secondary(void) { - 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. - */ - write_pen_release(cpu_logical_map(cpu)); - - arch_send_wakeup_ipi_mask(cpumask_of(cpu)); + struct device_node *np; + static void __iomem *backupram; - timeout = jiffies + (1 * HZ); - while (time_before(jiffies, timeout)) { - if (pen_release == -1) - break; + np = of_find_compatible_node(NULL, NULL, "ste,dbx500-backupram"); + if (!np) { + pr_err("No backupram base address\n"); + return; + } + backupram = of_iomap(np, 0); + of_node_put(np); + if (!backupram) { + pr_err("No backupram remap\n"); + return; } /* - * 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; -} - -static void __init wakeup_secondary(void) -{ - /* * write the address of secondary startup into the backup ram register * at offset 0x1FF4, then write the magic number 0xA1FEED01 to the * backup ram register at offset 0x1FF0, which is what boot rom code - * is waiting for. This would wake up the secondary core from WFE + * is waiting for. This will wake up the secondary core from WFE. */ -#define UX500_CPU1_JUMPADDR_OFFSET 0x1FF4 - __raw_writel(virt_to_phys(u8500_secondary_startup), - backupram + UX500_CPU1_JUMPADDR_OFFSET); - -#define UX500_CPU1_WAKEMAGIC_OFFSET 0x1FF0 - __raw_writel(0xA1FEED01, - backupram + UX500_CPU1_WAKEMAGIC_OFFSET); + writel(virt_to_phys(secondary_startup), + backupram + UX500_CPU1_JUMPADDR_OFFSET); + writel(0xA1FEED01, + backupram + UX500_CPU1_WAKEMAGIC_OFFSET); /* make sure write buffer is drained */ mb(); + iounmap(backupram); } -/* - * Initialise the CPU possible map early - this describes the CPUs - * which may be present or become present in the system. - */ -static void __init ux500_smp_init_cpus(void) +static void __init ux500_smp_prepare_cpus(unsigned int max_cpus) { - unsigned int i, ncores; struct device_node *np; + static void __iomem *scu_base; + unsigned int ncores; + int i; np = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu"); + if (!np) { + pr_err("No SCU base address\n"); + return; + } scu_base = of_iomap(np, 0); of_node_put(np); - if (!scu_base) + if (!scu_base) { + pr_err("No SCU remap\n"); return; - backupram = ioremap(U8500_BACKUPRAM0_BASE, SZ_8K); - ncores = scu_get_core_count(scu_base); - - /* sanity check */ - if (ncores > nr_cpu_ids) { - pr_warn("SMP: %u cores greater than maximum (%u), clipping\n", - ncores, nr_cpu_ids); - ncores = nr_cpu_ids; } + scu_enable(scu_base); + ncores = scu_get_core_count(scu_base); for (i = 0; i < ncores; i++) set_cpu_possible(i, true); + iounmap(scu_base); } -static void __init ux500_smp_prepare_cpus(unsigned int max_cpus) +static int ux500_boot_secondary(unsigned int cpu, struct task_struct *idle) { - scu_enable(scu_base); wakeup_secondary(); + arch_send_wakeup_ipi_mask(cpumask_of(cpu)); + return 0; } struct smp_operations ux500_smp_ops __initdata = { - .smp_init_cpus = ux500_smp_init_cpus, .smp_prepare_cpus = ux500_smp_prepare_cpus, - .smp_secondary_init = ux500_secondary_init, .smp_boot_secondary = ux500_boot_secondary, #ifdef CONFIG_HOTPLUG_CPU .cpu_die = ux500_cpu_die, #endif }; +CPU_METHOD_OF_DECLARE(ux500_smp, "ste,dbx500-smp", &ux500_smp_ops); diff --git a/arch/arm/mach-ux500/setup.h b/arch/arm/mach-ux500/setup.h index 1fb6ad2789f1..65876eac0761 100644 --- a/arch/arm/mach-ux500/setup.h +++ b/arch/arm/mach-ux500/setup.h @@ -26,7 +26,6 @@ extern struct device *ux500_soc_device_init(const char *soc_id); extern void ux500_timer_init(void); -extern struct smp_operations ux500_smp_ops; extern void ux500_cpu_die(unsigned int cpu); #endif /* __ASM_ARCH_SETUP_H */

[stable/v4.2.y] ARM: ux500: simplify secondary CPU boot

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