Re: [Xen-devel] [PATCH 7/7] xen/arm: Use the hardware ID TMP boot correctly secondary cpus

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Fri, 2013-08-30 at 14:30 +0100, Julien Grall wrote:

TMP in subject == "to"?

> Secondary CPUs will spin in head.S until their MPIDR[23:0] correspond to
> the smp_up_cpu. Actually Xen will set the value with the logical CPU ID
> which is wrong. Use the cpu_logical_map to get the correct CPU ID.
> 
> Acked-by: Julien Grall <julien.grall@xxxxxxxxxx>

S-o-b?

> ---
>  xen/arch/arm/smpboot.c |   20 +++++++++++++++-----
>  1 file changed, 15 insertions(+), 5 deletions(-)
> 
> diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c
> index c0d25de..1952287 100644
> --- a/xen/arch/arm/smpboot.c
> +++ b/xen/arch/arm/smpboot.c
> @@ -124,8 +124,7 @@ make_cpus_ready(unsigned int max_cpus, unsigned long 
> boot_phys_offset)
>      for ( i = 1; i < max_cpus; i++ )
>      {
>          /* Tell the next CPU to get ready */
> -        /* TODO: handle boards where CPUIDs are not contiguous */
> -        *gate = i;
> +        *gate = cpu_logical_map(i);
>          flush_xen_dcache(*gate);
>          isb();
>          sev();
> @@ -139,11 +138,22 @@ make_cpus_ready(unsigned int max_cpus, unsigned long 
> boot_phys_offset)
>  /* Boot the current CPU */
>  void __cpuinit start_secondary(unsigned long boot_phys_offset,
>                                 unsigned long fdt_paddr,
> -                               unsigned long cpuid)
> +                               unsigned long hwid)
>  {
> +    unsigned int cpuid;
> +
>      memset(get_cpu_info(), 0, sizeof (struct cpu_info));
>  
> -    /* TODO: handle boards where CPUIDs are not contiguous */
> +    /* Browse the logical map and find the associate logical cpu ID */
> +    for ( cpuid = 1; cpuid < nr_cpu_ids; cpuid++ )
> +    {
> +        if ( cpu_logical_map(cpuid) == hwid )
> +            break;
> +    }
> +
> +    if ( cpuid == nr_cpu_ids )
> +        panic("Can't find logical CPU id for cpu MPIDR[23:0] = 0x%lx\n", 
> hwid);

We could stumble on without this cpu.

> +
>      set_processor_id(cpuid);
>  
>      current_cpu_data = boot_cpu_data;
> @@ -232,7 +242,7 @@ int __cpu_up(unsigned int cpu)
>  
>      /* Unblock the CPU.  It should be waiting in the loop in head.S
>       * for an event to arrive when smp_up_cpu matches its cpuid. */
> -    smp_up_cpu = cpu;
> +    smp_up_cpu = cpu_logical_map(cpu);
>      /* we need to make sure that the change to smp_up_cpu is visible to
>       * secondary cpus with D-cache off */
>      flush_xen_dcache(smp_up_cpu);



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