cregit-Linux how code gets into the kernel

Release 4.11 arch/arm/kernel/psci_smp.c

Directory: arch/arm/kernel
/*
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * Copyright (C) 2012 ARM Limited
 *
 * Author: Will Deacon <will.deacon@arm.com>
 */

#include <linux/init.h>
#include <linux/smp.h>
#include <linux/of.h>
#include <linux/delay.h>
#include <linux/psci.h>

#include <uapi/linux/psci.h>

#include <asm/psci.h>
#include <asm/smp_plat.h>

/*
 * psci_smp assumes that the following is true about PSCI:
 *
 * cpu_suspend   Suspend the execution on a CPU
 * @state        we don't currently describe affinity levels, so just pass 0.
 * @entry_point  the first instruction to be executed on return
 * returns 0  success, < 0 on failure
 *
 * cpu_off       Power down a CPU
 * @state        we don't currently describe affinity levels, so just pass 0.
 * no return on successful call
 *
 * cpu_on        Power up a CPU
 * @cpuid        cpuid of target CPU, as from MPIDR
 * @entry_point  the first instruction to be executed on return
 * returns 0  success, < 0 on failure
 *
 * migrate       Migrate the context to a different CPU
 * @cpuid        cpuid of target CPU, as from MPIDR
 * returns 0  success, < 0 on failure
 *
 */

extern void secondary_startup(void);


static int psci_boot_secondary(unsigned int cpu, struct task_struct *idle) { if (psci_ops.cpu_on) return psci_ops.cpu_on(cpu_logical_map(cpu), virt_to_idmap(&secondary_startup)); return -ENODEV; }

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PersonTokensPropCommitsCommitProp
Stefano Stabellini4095.24%150.00%
Grygorii Strashko24.76%150.00%
Total42100.00%2100.00%

#ifdef CONFIG_HOTPLUG_CPU
int psci_cpu_disable(unsigned int cpu) { /* Fail early if we don't have CPU_OFF support */ if (!psci_ops.cpu_off) return -EOPNOTSUPP; /* Trusted OS will deny CPU_OFF */ if (psci_tos_resident_on(cpu)) return -EPERM; return 0; }

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Mark Rutland36100.00%1100.00%
Total36100.00%1100.00%


void psci_cpu_die(unsigned int cpu) { u32 state = PSCI_POWER_STATE_TYPE_POWER_DOWN << PSCI_0_2_POWER_STATE_TYPE_SHIFT; if (psci_ops.cpu_off) psci_ops.cpu_off(state); /* We should never return */ panic("psci: cpu %d failed to shutdown\n", cpu); }

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PersonTokensPropCommitsCommitProp
Stefano Stabellini3286.49%150.00%
Mark Rutland513.51%150.00%
Total37100.00%2100.00%


int psci_cpu_kill(unsigned int cpu) { int err, i; if (!psci_ops.affinity_info) return 1; /* * cpu_kill could race with cpu_die and we can * potentially end up declaring this cpu undead * while it is dying. So, try again a few times. */ for (i = 0; i < 10; i++) { err = psci_ops.affinity_info(cpu_logical_map(cpu), 0); if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) { pr_info("CPU%d killed.\n", cpu); return 1; } msleep(10); pr_info("Retrying again to check for CPU kill\n"); } pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n", cpu, err); /* Make platform_cpu_kill() fail. */ return 0; }

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Ashwin Chaugule95100.00%1100.00%
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#endif
bool __init psci_smp_available(void) { /* is cpu_on available at least? */ return (psci_ops.cpu_on != NULL); }

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Stefano Stabellini18100.00%1100.00%
Total18100.00%1100.00%

const struct smp_operations psci_smp_ops __initconst = { .smp_boot_secondary = psci_boot_secondary, #ifdef CONFIG_HOTPLUG_CPU .cpu_disable = psci_cpu_disable, .cpu_die = psci_cpu_die, .cpu_kill = psci_cpu_kill, #endif };

Overall Contributors

PersonTokensPropCommitsCommitProp
Stefano Stabellini13444.67%116.67%
Ashwin Chaugule10635.33%116.67%
Mark Rutland4916.33%116.67%
Arnd Bergmann72.33%116.67%
Grygorii Strashko20.67%116.67%
Masahiro Yamada20.67%116.67%
Total300100.00%6100.00%
Directory: arch/arm/kernel
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