Re: [Xen-devel] [PATCH v4 1/2] arm: introduce psci_smp_ops

[Nicolas Pitre <nicolas.pitre@xxxxxxxxxx>]

On Fri, 29 Mar 2013, Stefano Stabellini wrote:

> Rename virt_smp_ops to psci_smp_ops and move them to 
> arch/arm/kernel/psci_smp.c.
> Remove mach-virt/platsmp.c, now unused.
> Compile psci_smp if CONFIG_ARM_PSCI and CONFIG_SMP.
> 
> Add a cpu_die smp_op based on psci_ops.cpu_off.
> 
> Initialize PSCI before setting smp_ops in setup_arch.
> Use psci_smp_ops if the platform doesn't provide its own smp_ops.
> 
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
> CC: will.deacon@xxxxxxx
> CC: arnd@xxxxxxxx
> CC: marc.zyngier@xxxxxxx
> CC: linux@xxxxxxxxxxxxxxxx
> CC: nico@xxxxxxxxxx

Acked-by: Nicolas Pitre <nico@xxxxxxxxxx>


> ---
>  arch/arm/include/asm/psci.h  |    9 +++++
>  arch/arm/kernel/Makefile     |    5 ++-
>  arch/arm/kernel/psci.c       |    3 +-
>  arch/arm/kernel/psci_smp.c   |   67 
> ++++++++++++++++++++++++++++++++++++++++++
>  arch/arm/kernel/setup.c      |    7 ++++-
>  arch/arm/mach-virt/Makefile  |    1 -
>  arch/arm/mach-virt/platsmp.c |   58 ------------------------------------
>  arch/arm/mach-virt/virt.c    |    3 --
>  8 files changed, 87 insertions(+), 66 deletions(-)
>  create mode 100644 arch/arm/kernel/psci_smp.c
>  delete mode 100644 arch/arm/mach-virt/platsmp.c
> 
> diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h
> index ce0dbe7..4134dda 100644
> --- a/arch/arm/include/asm/psci.h
> +++ b/arch/arm/include/asm/psci.h
> @@ -32,5 +32,14 @@ struct psci_operations {
>  };
>  
>  extern struct psci_operations psci_ops;
> +extern struct smp_operations psci_smp_ops;
>  
> +#ifdef CONFIG_ARM_PSCI
> +int psci_init(void);
> +bool psci_smp_available(void);
> +#else
> +static inline int psci_init(void) { return -ENODEV; }
> +static inline bool psci_smp_available(void) { return false; }
> +#endif
> + 
>  #endif /* __ASM_ARM_PSCI_H */
> diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
> index 5f3338e..dd9d90a 100644
> --- a/arch/arm/kernel/Makefile
> +++ b/arch/arm/kernel/Makefile
> @@ -82,6 +82,9 @@ obj-$(CONFIG_DEBUG_LL)      += debug.o
>  obj-$(CONFIG_EARLY_PRINTK)   += early_printk.o
>  
>  obj-$(CONFIG_ARM_VIRT_EXT)   += hyp-stub.o
> -obj-$(CONFIG_ARM_PSCI)               += psci.o
> +ifeq ($(CONFIG_ARM_PSCI),y)
> +obj-y                                += psci.o
> +obj-$(CONFIG_SMP)            += psci_smp.o
> +endif
>  
>  extra-y := $(head-y) vmlinux.lds
> diff --git a/arch/arm/kernel/psci.c b/arch/arm/kernel/psci.c
> index 3653164..acb968b 100644
> --- a/arch/arm/kernel/psci.c
> +++ b/arch/arm/kernel/psci.c
> @@ -158,7 +158,7 @@ static const struct of_device_id psci_of_match[] 
> __initconst = {
>       {},
>  };
>  
> -static int __init psci_init(void)
> +int __init psci_init(void)
>  {
>       struct device_node *np;
>       const char *method;
> @@ -208,4 +208,3 @@ out_put_node:
>       of_node_put(np);
>       return 0;
>  }
> -early_initcall(psci_init);
> diff --git a/arch/arm/kernel/psci_smp.c b/arch/arm/kernel/psci_smp.c
> new file mode 100644
> index 0000000..66b0f77
> --- /dev/null
> +++ b/arch/arm/kernel/psci_smp.c
> @@ -0,0 +1,67 @@
> +/*
> + * 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@xxxxxxx>
> + */
> +
> +#include <linux/init.h>
> +#include <linux/irqchip/arm-gic.h>
> +#include <linux/smp.h>
> +#include <linux/of.h>
> +
> +#include <asm/psci.h>
> +#include <asm/smp_plat.h>
> +
> +extern void secondary_startup(void);
> +
> +static int __cpuinit psci_boot_secondary(unsigned int cpu,
> +                                      struct task_struct *idle)
> +{
> +     if (psci_ops.cpu_on)
> +             return psci_ops.cpu_on(cpu_logical_map(cpu),
> +                                    __pa(secondary_startup));
> +     return -ENODEV;
> +}
> +
> +static void __cpuinit psci_secondary_init(unsigned int cpu)
> +{
> +     gic_secondary_init(0);
> +}
> +
> +#ifdef CONFIG_HOTPLUG_CPU
> +void __ref psci_cpu_die(unsigned int cpu)
> +{
> +       const struct psci_power_state ps = {
> +               .type = PSCI_POWER_STATE_TYPE_POWER_DOWN,
> +       };
> +
> +       if (psci_ops.cpu_off)
> +               psci_ops.cpu_off(ps);
> +
> +       /* We should never return */
> +       panic("psci: cpu %d failed to shutdown\n", cpu);
> +}
> +#else
> +#define psci_cpu_die NULL
> +#endif
> +
> +bool __init psci_smp_available(void)
> +{
> +     /* is cpu_on available at least? */
> +     return (psci_ops.cpu_on != NULL);
> +}
> +
> +struct smp_operations __initdata psci_smp_ops = {
> +     .smp_secondary_init     = psci_secondary_init,
> +     .smp_boot_secondary     = psci_boot_secondary,
> +     .cpu_die                = psci_cpu_die,
> +};
> diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
> index 3f6cbb2..341efaa 100644
> --- a/arch/arm/kernel/setup.c
> +++ b/arch/arm/kernel/setup.c
> @@ -36,6 +36,7 @@
>  #include <asm/cputype.h>
>  #include <asm/elf.h>
>  #include <asm/procinfo.h>
> +#include <asm/psci.h>
>  #include <asm/sections.h>
>  #include <asm/setup.h>
>  #include <asm/smp_plat.h>
> @@ -766,9 +767,13 @@ void __init setup_arch(char **cmdline_p)
>       unflatten_device_tree();
>  
>       arm_dt_init_cpu_maps();
> +     psci_init();
>  #ifdef CONFIG_SMP
>       if (is_smp()) {
> -             smp_set_ops(mdesc->smp);
> +             if (mdesc->smp)
> +                     smp_set_ops(mdesc->smp);
> +             else if (psci_smp_available())
> +                     smp_set_ops(&psci_smp_ops);
>               smp_init_cpus();
>       }
>  #endif
> diff --git a/arch/arm/mach-virt/Makefile b/arch/arm/mach-virt/Makefile
> index 042afc1..7ddbfa6 100644
> --- a/arch/arm/mach-virt/Makefile
> +++ b/arch/arm/mach-virt/Makefile
> @@ -3,4 +3,3 @@
>  #
>  
>  obj-y                                        := virt.o
> -obj-$(CONFIG_SMP)                    += platsmp.o
> diff --git a/arch/arm/mach-virt/platsmp.c b/arch/arm/mach-virt/platsmp.c
> deleted file mode 100644
> index 8badaab..0000000
> --- a/arch/arm/mach-virt/platsmp.c
> +++ /dev/null
> @@ -1,58 +0,0 @@
> -/*
> - * Dummy Virtual Machine - does what it says on the tin.
> - *
> - * Copyright (C) 2012 ARM Ltd
> - * Author: Will Deacon <will.deacon@xxxxxxx>
> - *
> - * 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.
> - *
> - * You should have received a copy of the GNU General Public License
> - * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> - */
> -
> -#include <linux/init.h>
> -#include <linux/smp.h>
> -#include <linux/of.h>
> -
> -#include <linux/irqchip/arm-gic.h>
> -
> -#include <asm/psci.h>
> -#include <asm/smp_plat.h>
> -
> -extern void secondary_startup(void);
> -
> -static void __init virt_smp_init_cpus(void)
> -{
> -}
> -
> -static void __init virt_smp_prepare_cpus(unsigned int max_cpus)
> -{
> -}
> -
> -static int __cpuinit virt_boot_secondary(unsigned int cpu,
> -                                      struct task_struct *idle)
> -{
> -     if (psci_ops.cpu_on)
> -             return psci_ops.cpu_on(cpu_logical_map(cpu),
> -                                    __pa(secondary_startup));
> -     return -ENODEV;
> -}
> -
> -static void __cpuinit virt_secondary_init(unsigned int cpu)
> -{
> -     gic_secondary_init(0);
> -}
> -
> -struct smp_operations __initdata virt_smp_ops = {
> -     .smp_init_cpus          = virt_smp_init_cpus,
> -     .smp_prepare_cpus       = virt_smp_prepare_cpus,
> -     .smp_secondary_init     = virt_secondary_init,
> -     .smp_boot_secondary     = virt_boot_secondary,
> -};
> diff --git a/arch/arm/mach-virt/virt.c b/arch/arm/mach-virt/virt.c
> index 528c05e..c417752 100644
> --- a/arch/arm/mach-virt/virt.c
> +++ b/arch/arm/mach-virt/virt.c
> @@ -44,12 +44,9 @@ static const char *virt_dt_match[] = {
>       NULL
>  };
>  
> -extern struct smp_operations virt_smp_ops;
> -
>  DT_MACHINE_START(VIRT, "Dummy Virtual Machine")
>       .init_irq       = irqchip_init,
>       .init_time      = virt_timer_init,
>       .init_machine   = virt_init,
> -     .smp            = smp_ops(virt_smp_ops),
>       .dt_compat      = virt_dt_match,
>  MACHINE_END
> -- 
> 1.7.2.5
> 

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