Re: [Xen-devel] [PATCH v3 06/11] xen: arm: implement arch/platform SMP and CPU initialisation framework

[Julien Grall <julien.grall@xxxxxxxxxx>]

On 09/27/2013 11:20 AM, Ian Campbell wrote:
> Includes an implementation for vexpress using the sysflags interface and
> support for the ARMv8 "spin-table" method.
> 
> Unused until the next patch, split out to simplify review.
> 
> Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
> Acked-by: Tim Deegan <tim@xxxxxxx>
> Acked-by: Julien Grall <julien.grall@xxxxxxxxxx>
> ---
>  xen/arch/arm/arm32/Makefile       |    1 +
>  xen/arch/arm/arm32/head.S         |    2 +-
>  xen/arch/arm/arm32/smpboot.c      |   29 ++++++++++++
>  xen/arch/arm/arm64/Makefile       |    1 +
>  xen/arch/arm/arm64/head.S         |    1 +
>  xen/arch/arm/arm64/smpboot.c      |   89 
> +++++++++++++++++++++++++++++++++++++
>  xen/arch/arm/platform.c           |   18 ++++++++
>  xen/arch/arm/platforms/vexpress.c |   38 ++++++++++++++++
>  xen/include/asm-arm/platform.h    |    9 ++++
>  xen/include/asm-arm/smp.h         |    9 ++++
>  10 files changed, 196 insertions(+), 1 deletion(-)
>  create mode 100644 xen/arch/arm/arm32/smpboot.c
>  create mode 100644 xen/arch/arm/arm64/smpboot.c
> 
> diff --git a/xen/arch/arm/arm32/Makefile b/xen/arch/arm/arm32/Makefile
> index 18522dc..463b1f5 100644
> --- a/xen/arch/arm/arm32/Makefile
> +++ b/xen/arch/arm/arm32/Makefile
> @@ -7,5 +7,6 @@ obj-y += proc-v7.o
>  obj-y += traps.o
>  obj-y += domain.o
>  obj-y += vfp.o
> +obj-y += smpboot.o
>  
>  obj-$(EARLY_PRINTK) += debug.o
> diff --git a/xen/arch/arm/arm32/head.S b/xen/arch/arm/arm32/head.S
> index fce18a2..8cb31a2 100644
> --- a/xen/arch/arm/arm32/head.S
> +++ b/xen/arch/arm/arm32/head.S
> @@ -59,7 +59,7 @@
>           * or the initial pagetable code below will need adjustment. */
>          .global start
>  start:
> -
> +GLOBAL(init_secondary) /* currently unused */
>          /* zImage magic header, see:
>           * 
> http://www.simtec.co.uk/products/SWLINUX/files/booting_article.html#d0e309
>           */
> diff --git a/xen/arch/arm/arm32/smpboot.c b/xen/arch/arm/arm32/smpboot.c
> new file mode 100644
> index 0000000..88fe8fb
> --- /dev/null
> +++ b/xen/arch/arm/arm32/smpboot.c
> @@ -0,0 +1,29 @@
> +#include <xen/device_tree.h>
> +#include <xen/init.h>
> +#include <xen/smp.h>
> +#include <asm/platform.h>
> +
> +int __init arch_smp_init(void)
> +{
> +    return platform_smp_init();
> +}
> +
> +int __init arch_cpu_init(int cpu, struct dt_device_node *dn)
> +{
> +    /* TODO handle PSCI init */
> +    return 0;
> +}
> +
> +int __init arch_cpu_up(int cpu)
> +{
> +    return platform_cpu_up(cpu);
> +}
> +
> +/*
> + * Local variables:
> + * mode: C
> + * c-file-style: "BSD"
> + * c-basic-offset: 4
> + * indent-tabs-mode: nil
> + * End:
> + */
> diff --git a/xen/arch/arm/arm64/Makefile b/xen/arch/arm/arm64/Makefile
> index e06a0a9..30fb480 100644
> --- a/xen/arch/arm/arm64/Makefile
> +++ b/xen/arch/arm/arm64/Makefile
> @@ -6,5 +6,6 @@ obj-y += mode_switch.o
>  obj-y += traps.o
>  obj-y += domain.o
>  obj-y += vfp.o
> +obj-y += smpboot.o
>  
>  obj-$(EARLY_PRINTK) += debug.o
> diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S
> index 4495f72..7cecac3 100644
> --- a/xen/arch/arm/arm64/head.S
> +++ b/xen/arch/arm/arm64/head.S
> @@ -65,6 +65,7 @@
>  
>          .global start
>  start:
> +GLOBAL(init_secondary) /* currently unused */
>          /*
>           * DO NOT MODIFY. Image header expected by Linux boot-loaders.
>           */
> diff --git a/xen/arch/arm/arm64/smpboot.c b/xen/arch/arm/arm64/smpboot.c
> new file mode 100644
> index 0000000..8239590
> --- /dev/null
> +++ b/xen/arch/arm/arm64/smpboot.c
> @@ -0,0 +1,89 @@
> +#include <xen/cpu.h>
> +#include <xen/lib.h>
> +#include <xen/init.h>
> +#include <xen/errno.h>
> +#include <xen/mm.h>
> +#include <xen/smp.h>
> +
> +struct smp_enable_ops {
> +        int             (*prepare_cpu)(int);
> +};
> +
> +static paddr_t cpu_release_addr[NR_CPUS];
> +static struct smp_enable_ops smp_enable_ops[NR_CPUS];
> +
> +static int __init smp_spin_table_cpu_up(int cpu)
> +{
> +    paddr_t *release;
> +
> +    if (!cpu_release_addr[cpu])
> +    {
> +        printk("CPU%d: No release addr\n", cpu);
> +        return -ENODEV;
> +    }
> +
> +    release = __va(cpu_release_addr[cpu]);
> +
> +    release[0] = __pa(init_secondary);
> +    flush_xen_data_tlb_range_va((vaddr_t)release, sizeof(*release));
> +
> +    sev();
> +    return 0;
> +}
> +
> +static void __init smp_spin_table_init(int cpu, struct dt_device_node *dn)
> +{
> +    if ( !dt_property_read_u64(dn, "cpu-release-addr", 
> &cpu_release_addr[cpu]) )
> +    {
> +        printk("CPU%d has no cpu-release-addr\n", cpu);
> +        return;
> +    }
> +
> +    smp_enable_ops[cpu].prepare_cpu = smp_spin_table_cpu_up;
> +}
> +
> +int __init arch_smp_init(void)
> +{
> +    /* Nothing */
> +    return 0;
> +}
> +
> +int __init arch_cpu_init(int cpu, struct dt_device_node *dn)
> +{
> +    const char *enable_method;
> +
> +    enable_method = dt_get_property(dn, "enable-method", NULL);
> +    if (!enable_method)
> +    {
> +        printk("CPU%d has no enable method\n", cpu);
> +        return -EINVAL;
> +    }
> +
> +    if ( !strcmp(enable_method, "spin-table") )
> +        smp_spin_table_init(cpu, dn);
> +    /* TODO: method "psci" */
> +    else
> +    {
> +        printk("CPU%d has unknown enable method \"%s\"\n", cpu, 
> enable_method);
> +        return -EINVAL;
> +    }
> +
> +    return 0;
> +}
> +
> +int __init arch_cpu_up(int cpu)
> +{
> +    if ( !smp_enable_ops[cpu].prepare_cpu )
> +        return -ENODEV;
> +
> +    return smp_enable_ops[cpu].prepare_cpu(cpu);
> +}
> +
> +/*
> + * Local variables:
> + * mode: C
> + * c-file-style: "BSD"
> + * c-basic-offset: 4
> + * indent-tabs-mode: nil
> + * End:
> + */
> diff --git a/xen/arch/arm/platform.c b/xen/arch/arm/platform.c
> index db79368..db135f8 100644
> --- a/xen/arch/arm/platform.c
> +++ b/xen/arch/arm/platform.c
> @@ -105,6 +105,24 @@ int __init platform_specific_mapping(struct domain *d)
>      return res;
>  }
>  
> +#ifdef CONFIG_ARM_32
> +int __init platform_cpu_up(int cpu)
> +{
> +    if ( platform && platform->cpu_up )
> +        return platform->cpu_up(cpu);
> +
> +    return -EAGAIN;
> +}
> +
> +int __init platform_smp_init(void)
> +{
> +    if ( platform && platform->smp_init )
> +        return platform->smp_init();
> +
> +    return 0;
> +}
> +#endif
> +
>  void platform_reset(void)
>  {
>      if ( platform && platform->reset )
> diff --git a/xen/arch/arm/platforms/vexpress.c 
> b/xen/arch/arm/platforms/vexpress.c
> index 22c0c13..be0516f 100644
> --- a/xen/arch/arm/platforms/vexpress.c
> +++ b/xen/arch/arm/platforms/vexpress.c
> @@ -22,6 +22,7 @@
>  #include <xen/mm.h>
>  #include <xen/vmap.h>
>  #include <asm/io.h>
> +#include <asm/gic.h>
>  
>  #define DCC_SHIFT      26
>  #define FUNCTION_SHIFT 20
> @@ -120,6 +121,39 @@ static void vexpress_reset(void)
>      iounmap(sp810);
>  }
>  
> +#ifdef CONFIG_ARM_32
> +
> +static int vexpress_smp_init(void)

platform_smp_init is in init section. vexpress_smp should also be here.

> +{
> +    void __iomem *sysflags;
> +
> +    sysflags = ioremap_nocache(V2M_SYS_MMIO_BASE, PAGE_SIZE);
> +    if ( !sysflags )
> +    {
> +        dprintk(XENLOG_ERR, "Unable to map vexpress MMIO\n");
> +        return -EFAULT;
> +    }
> +
> +    printk("Set SYS_FLAGS to %"PRIpaddr" (%p)\n",
> +           __pa(init_secondary), init_secondary);
> +    writel(~0, sysflags + V2M_SYS_FLAGSCLR);
> +    writel(__pa(init_secondary), sysflags + V2M_SYS_FLAGSSET);
> +
> +    iounmap(sysflags);
> +
> +    return 0;
> +}
> +
> +static int vexpress_cpu_up(int cpu)

same here.

> +{
> +    /* Nothing to do here, the generic sev() will suffice to kick CPUs
> +     * out of either the firmware or our own smp_up_cpu gate,
> +     * depending on where they have ended up. */
> +
> +    return 0;
> +}
> +#endif
> +
>  static const char * const vexpress_dt_compat[] __initdata =
>  {
>      "arm,vexpress",
> @@ -144,6 +178,10 @@ static const struct dt_device_match 
> vexpress_blacklist_dev[] __initconst =
>  
>  PLATFORM_START(vexpress, "VERSATILE EXPRESS")
>      .compatible = vexpress_dt_compat,
> +#ifdef CONFIG_ARM_32
> +    .smp_init = vexpress_smp_init,
> +    .cpu_up = vexpress_cpu_up,
> +#endif
>      .reset = vexpress_reset,
>      .blacklist_dev = vexpress_blacklist_dev,
>  PLATFORM_END
> diff --git a/xen/include/asm-arm/platform.h b/xen/include/asm-arm/platform.h
> index a19dbf7..dbd2a15 100644
> --- a/xen/include/asm-arm/platform.h
> +++ b/xen/include/asm-arm/platform.h
> @@ -15,6 +15,11 @@ struct platform_desc {
>      /* Platform initialization */
>      int (*init)(void);
>      int (*init_time)(void);
> +#ifdef CONFIG_ARM_32
> +    /* SMP */
> +    int (*smp_init)(void);
> +    int (*cpu_up)(int cpu);
> +#endif
>      /* Specific mapping for dom0 */
>      int (*specific_mapping)(struct domain *d);
>      /* Platform reset */
> @@ -43,6 +48,10 @@ struct platform_desc {
>  int __init platform_init(void);
>  int __init platform_init_time(void);
>  int __init platform_specific_mapping(struct domain *d);
> +#ifdef CONFIG_ARM_32
> +int platform_smp_init(void);
> +int platform_cpu_up(int cpu);
> +#endif
>  void platform_reset(void);
>  void platform_poweroff(void);
>  bool_t platform_has_quirk(uint32_t quirk);
> diff --git a/xen/include/asm-arm/smp.h b/xen/include/asm-arm/smp.h
> index 1c2746b..1added5 100644
> --- a/xen/include/asm-arm/smp.h
> +++ b/xen/include/asm-arm/smp.h
> @@ -4,6 +4,7 @@
>  #ifndef __ASSEMBLY__
>  #include <xen/config.h>
>  #include <xen/cpumask.h>
> +#include <xen/device_tree.h>
>  #include <asm/current.h>
>  #endif
>  
> @@ -22,9 +23,17 @@ extern void stop_cpu(void);
>  extern void
>  make_cpus_ready(unsigned int max_cpus, unsigned long boot_phys_offset);
>  
> +extern int arch_smp_init(void);
> +extern int arch_cpu_init(int cpu, struct dt_device_node *dn);
> +extern int arch_cpu_up(int cpu);
> +
> +/* Secondary CPU entry point */
> +extern void init_secondary(void);
> +
>  extern void smp_clear_cpu_maps (void);
>  extern int smp_get_max_cpus (void);
>  #endif
> +
>  /*
>   * Local variables:
>   * mode: C
> 


-- 
Julien Grall

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