cregit-Linux how code gets into the kernel

Release 4.11 arch/arm/mach-prima2/platsmp.c

/*
 * plat smp support for CSR Marco dual-core SMP SoCs
 *
 * Copyright (c) 2012 Cambridge Silicon Radio Limited, a CSR plc group company.
 *
 * Licensed under GPLv2 or later.
 */

#include <linux/init.h>
#include <linux/smp.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <asm/page.h>
#include <asm/mach/map.h>
#include <asm/smp_plat.h>
#include <asm/smp_scu.h>
#include <asm/cacheflush.h>
#include <asm/cputype.h>

#include "common.h"


static void __iomem *clk_base;

static DEFINE_SPINLOCK(boot_lock);


static void sirfsoc_secondary_init(unsigned int cpu) { /* * let the primary processor know we're out of the * pen, then head off into the C entry point */ pen_release = -1; smp_wmb(); /* * Synchronise with the boot thread. */ spin_lock(&boot_lock); spin_unlock(&boot_lock); }

Contributors

PersonTokensPropCommitsCommitProp
Barry Song32100.00%1100.00%
Total32100.00%1100.00%

static const struct of_device_id clk_ids[] = { { .compatible = "sirf,atlas7-clkc" }, {}, };
static int sirfsoc_boot_secondary(unsigned int cpu, struct task_struct *idle) { unsigned long timeout; struct device_node *np; np = of_find_matching_node(NULL, clk_ids); if (!np) return -ENODEV; clk_base = of_iomap(np, 0); if (!clk_base) return -ENOMEM; /* * write the address of secondary startup into the clkc register * at offset 0x2bC, then write the magic number 0x3CAF5D62 to the * clkc register at offset 0x2b8, which is what boot rom code is * waiting for. This would wake up the secondary core from WFE */ #define SIRFSOC_CPU1_JUMPADDR_OFFSET 0x2bc __raw_writel(__pa_symbol(sirfsoc_secondary_startup), clk_base + SIRFSOC_CPU1_JUMPADDR_OFFSET); #define SIRFSOC_CPU1_WAKEMAGIC_OFFSET 0x2b8 __raw_writel(0x3CAF5D62, clk_base + SIRFSOC_CPU1_WAKEMAGIC_OFFSET); /* make sure write buffer is drained */ mb(); 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. */ pen_release = cpu_logical_map(cpu); sync_cache_w(&pen_release); /* * Send the secondary CPU SEV, thereby causing the boot monitor to read * the JUMPADDR and WAKEMAGIC, and branch to the address found there. */ dsb_sev(); 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; }

Contributors

PersonTokensPropCommitsCommitProp
Barry Song16394.22%125.00%
Zhiwu Song84.62%125.00%
Florian Fainelli10.58%125.00%
Nico Pitre10.58%125.00%
Total173100.00%4100.00%

const struct smp_operations sirfsoc_smp_ops __initconst = { .smp_secondary_init = sirfsoc_secondary_init, .smp_boot_secondary = sirfsoc_boot_secondary, #ifdef CONFIG_HOTPLUG_CPU .cpu_die = sirfsoc_cpu_die, #endif };

Overall Contributors

PersonTokensPropCommitsCommitProp
Barry Song28594.68%116.67%
Zhiwu Song113.65%116.67%
Masahiro Yamada20.66%116.67%
Nico Pitre10.33%116.67%
Uwe Kleine-König10.33%116.67%
Florian Fainelli10.33%116.67%
Total301100.00%6100.00%
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