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linux/arch/arm/common/mcpm_platsmp.c

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ARM: mcpm: generic SMP secondary bringup and hotplug support Now that the cluster power API is in place, we can use it for SMP secondary bringup and CPU hotplug in a generic fashion. Signed-off-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Will Deacon <will.deacon@arm.com>
2012-11-20 05:02:17 +08:00
/*
* linux/arch/arm/mach-vexpress/mcpm_platsmp.c
*
* Created by: Nicolas Pitre, November 2012
* Copyright: (C) 2012-2013 Linaro Limited
*
* 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.
*
* Code to handle secondary CPU bringup and hotplug for the cluster power API.
*/
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/spinlock.h>
#include <asm/mcpm.h>
#include <asm/smp.h>
#include <asm/smp_plat.h>
arm: delete __cpuinit/__CPUINIT usage from all ARM users The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) and are flagged as __cpuinit -- so if we remove the __cpuinit from the arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit related content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. This removes all the ARM uses of the __cpuinit macros from C code, and all __CPUINIT from assembly code. It also had two ".previous" section statements that were paired off against __CPUINIT (aka .section ".cpuinit.text") that also get removed here. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Russell King <linux@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-06-18 03:43:14 +08:00
static int mcpm_boot_secondary(unsigned int cpu, struct task_struct *idle)
ARM: mcpm: generic SMP secondary bringup and hotplug support Now that the cluster power API is in place, we can use it for SMP secondary bringup and CPU hotplug in a generic fashion. Signed-off-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Will Deacon <will.deacon@arm.com>
2012-11-20 05:02:17 +08:00
{
unsigned int mpidr, pcpu, pcluster, ret;
extern void secondary_startup(void);
mpidr = cpu_logical_map(cpu);
pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
pr_debug("%s: logical CPU %d is physical CPU %d cluster %d\n",
__func__, cpu, pcpu, pcluster);
mcpm_set_entry_vector(pcpu, pcluster, NULL);
ret = mcpm_cpu_power_up(pcpu, pcluster);
if (ret)
return ret;
mcpm_set_entry_vector(pcpu, pcluster, secondary_startup);
arch_send_wakeup_ipi_mask(cpumask_of(cpu));
dsb_sev();
return 0;
}
arm: delete __cpuinit/__CPUINIT usage from all ARM users The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) and are flagged as __cpuinit -- so if we remove the __cpuinit from the arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit related content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. This removes all the ARM uses of the __cpuinit macros from C code, and all __CPUINIT from assembly code. It also had two ".previous" section statements that were paired off against __CPUINIT (aka .section ".cpuinit.text") that also get removed here. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Russell King <linux@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-06-18 03:43:14 +08:00
static void mcpm_secondary_init(unsigned int cpu)
ARM: mcpm: generic SMP secondary bringup and hotplug support Now that the cluster power API is in place, we can use it for SMP secondary bringup and CPU hotplug in a generic fashion. Signed-off-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Will Deacon <will.deacon@arm.com>
2012-11-20 05:02:17 +08:00
{
mcpm_cpu_powered_up();
}
#ifdef CONFIG_HOTPLUG_CPU
static int mcpm_cpu_disable(unsigned int cpu)
{
/*
* We assume all CPUs may be shut down.
* This would be the hook to use for eventual Secure
* OS migration requests as described in the PSCI spec.
*/
return 0;
}
static void mcpm_cpu_die(unsigned int cpu)
{
unsigned int mpidr, pcpu, pcluster;
mpidr = read_cpuid_mpidr();
pcpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
pcluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
mcpm_set_entry_vector(pcpu, pcluster, NULL);
mcpm_cpu_power_down();
}
#endif
ARM: mcpm: provide an interface to set the SMP ops at run time This is cleaner than exporting the mcpm_smp_ops structure. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Jon Medhurst <tixy@linaro.org>
2013-04-09 13:29:17 +08:00
static struct smp_operations __initdata mcpm_smp_ops = {
ARM: mcpm: generic SMP secondary bringup and hotplug support Now that the cluster power API is in place, we can use it for SMP secondary bringup and CPU hotplug in a generic fashion. Signed-off-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Reviewed-by: Will Deacon <will.deacon@arm.com>
2012-11-20 05:02:17 +08:00
.smp_boot_secondary = mcpm_boot_secondary,
.smp_secondary_init = mcpm_secondary_init,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_disable = mcpm_cpu_disable,
.cpu_die = mcpm_cpu_die,
#endif
};
ARM: mcpm: provide an interface to set the SMP ops at run time This is cleaner than exporting the mcpm_smp_ops structure. Signed-off-by: Nicolas Pitre <nico@linaro.org> Acked-by: Jon Medhurst <tixy@linaro.org>
2013-04-09 13:29:17 +08:00
void __init mcpm_smp_set_ops(void)
{
smp_set_ops(&mcpm_smp_ops);
}
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