From mboxrd@z Thu Jan 1 00:00:00 1970 From: jun.nie@linaro.org (Jun Nie) Date: Sat, 14 Mar 2015 19:49:40 +0800 Subject: [PATCH 05/10] ARM: zx: bring up the secondary core In-Reply-To: <1426333785-3952-1-git-send-email-jun.nie@linaro.org> References: <1426333785-3952-1-git-send-email-jun.nie@linaro.org> Message-ID: <1426333785-3952-6-git-send-email-jun.nie@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Use release_pen mechanism to bring up the secondary core. Signed-off-by: Shawn Guo Signed-off-by: Jun Nie --- arch/arm/mach-zx/Makefile | 1 + arch/arm/mach-zx/core.h | 17 +++++ arch/arm/mach-zx/headsmp.S | 38 ++++++++++++ arch/arm/mach-zx/platsmp.c | 147 ++++++++++++++++++++++++++++++++++++++++++++ arch/arm/mach-zx/zx296702.c | 1 + 5 files changed, 204 insertions(+) create mode 100644 arch/arm/mach-zx/core.h create mode 100644 arch/arm/mach-zx/headsmp.S create mode 100644 arch/arm/mach-zx/platsmp.c diff --git a/arch/arm/mach-zx/Makefile b/arch/arm/mach-zx/Makefile index 7a541c7..7c2edf6 100644 --- a/arch/arm/mach-zx/Makefile +++ b/arch/arm/mach-zx/Makefile @@ -1 +1,2 @@ obj-$(CONFIG_SOC_ZX296702) += zx296702.o +obj-$(CONFIG_SMP) += headsmp.o platsmp.o diff --git a/arch/arm/mach-zx/core.h b/arch/arm/mach-zx/core.h new file mode 100644 index 0000000..400c7b4 --- /dev/null +++ b/arch/arm/mach-zx/core.h @@ -0,0 +1,17 @@ +/* + * Copyright 2014 Linaro Ltd. + * Copyright (C) 2014 ZTE Corporation. + * + * 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. + */ + +#ifndef __MACH_ZX_CORE_H +#define __MACH_ZX_CORE_H + +extern struct smp_operations zx_smp_ops; + +void zx_secondary_startup(void); + +#endif /* __MACH_ZX_CORE_H */ diff --git a/arch/arm/mach-zx/headsmp.S b/arch/arm/mach-zx/headsmp.S new file mode 100644 index 0000000..8f70ff7 --- /dev/null +++ b/arch/arm/mach-zx/headsmp.S @@ -0,0 +1,38 @@ +/* + * Copyright 2014 Linaro Ltd. + * Copyright (C) 2014 ZTE Corporation. + * + * 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 + +/* + * zx2967 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(zx_secondary_startup) + bl v7_invalidate_l1 + 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(zx_secondary_startup) + + .align 2 +1: .long . + .long pen_release diff --git a/arch/arm/mach-zx/platsmp.c b/arch/arm/mach-zx/platsmp.c new file mode 100644 index 0000000..e508a9c --- /dev/null +++ b/arch/arm/mach-zx/platsmp.c @@ -0,0 +1,147 @@ +/* + * Copyright 2014 Linaro Ltd. + * Copyright (C) 2014 ZTE Corporation. + * + * 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 +#include +#include +#include +#include +#include +#include + +#include +#include + +#include "core.h" + +#define AON_SYS_CTRL_RESERVED1 0xa8 + +static DEFINE_SPINLOCK(boot_lock); + +void __init zx_smp_prepare_cpus(unsigned int max_cpus) +{ + struct device_node *np; + unsigned long base = 0; + void __iomem *scu_base; + void __iomem *aonsysctrl_base; + + base = scu_a9_get_base(); + scu_base = ioremap(base, SZ_256); + if (!scu_base) { + pr_err("%s: failed to map scu\n", __func__); + return; + } + + scu_enable(scu_base); + iounmap(scu_base); + + np = of_find_compatible_node(NULL, NULL, "zte,aon-sysctrl"); + if (!np) { + pr_err("%s: failed to find sysctrl node\n", __func__); + return; + } + + aonsysctrl_base = of_iomap(np, 0); + if (!aonsysctrl_base) { + pr_err("%s: failed to map aonsysctrl\n", __func__); + of_node_put(np); + return; + } + + /* + * Write the address of secondary startup into the + * system-wide flags register. The BootMonitor waits + * until it receives a soft interrupt, and then the + * secondary CPU branches to this address. + */ + __raw_writel(virt_to_phys(zx_secondary_startup), + aonsysctrl_base + AON_SYS_CTRL_RESERVED1); + + iounmap(aonsysctrl_base); + of_node_put(np); +} + +/* + * 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; + /* make sure pen_release is visible */ + smp_wmb(); + sync_cache_w(&pen_release); +} + +static void zx_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 zx_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); + + /* + * This is really belt and braces; we hold unintended secondary + * CPUs in the holding pen until we're ready for them. However, + * since we haven't sent them a soft interrupt, they shouldn't + * be there. + */ + write_pen_release(cpu); + + /* + * Send the secondary CPU a soft interrupt, thereby causing + * the boot monitor to read the system wide flags register, + * and branch to the address found there. + */ + arch_send_wakeup_ipi_mask(cpumask_of(cpu)); + + timeout = jiffies + (1 * HZ); + while (time_before(jiffies, timeout)) { + /* sync pen_release value */ + 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; +} + +struct smp_operations zx_smp_ops __initdata = { + .smp_prepare_cpus = zx_smp_prepare_cpus, + .smp_secondary_init = zx_secondary_init, + .smp_boot_secondary = zx_boot_secondary, +}; diff --git a/arch/arm/mach-zx/zx296702.c b/arch/arm/mach-zx/zx296702.c index 9c055ea..d5d8be6 100644 --- a/arch/arm/mach-zx/zx296702.c +++ b/arch/arm/mach-zx/zx296702.c @@ -59,6 +59,7 @@ static const char *zx296702_dt_compat[] __initconst = { }; DT_MACHINE_START(ZX, "ZTE ZX296702 (Device Tree)") + .smp = smp_ops(zx_smp_ops), .dt_compat = zx296702_dt_compat, .init_machine = zx296702_init_machine, MACHINE_END -- 1.9.1