Re: [Xen-devel] [RFC PATCH v2] xen/arm: split the init_xen_time() in 2 parts

[Oleksandr Tyshchenko <oleksandr.tyshchenko@xxxxxxxxxxxxxxx>]

Hi, Ian

On Tue, Jan 27, 2015 at 6:43 PM, Ian Campbell <Ian.Campbell@xxxxxxxxxx> wrote:
> On Tue, 2015-01-27 at 15:39 +0200, Oleksandr Tyshchenko wrote:
>> Create preinit_xen_time() and move to it minimum required
>> subset of operations needed to properly initialized
>> cpu_khz and boot_count vars. This is allow us to use udelay()
>> immediately after the call.
>>
>> Changes in v2:
>> 1. Move timer_ids out of the find_timer_node() and frop this func.
>> 2. Use void as a return value for preinit_xen_time().
>> 3. Move platform_init() before calling preinit_xen_time().
>
> Please put these after the first --- so they get cut from the eventual
> commit log.
ok

>
> Apart from this the patch looks good to me, is there a reason I'm not
> aware of that it is still RFC?
No, it isn't.
I forgot to drop RFC when I was creating v2.

>
>>
>> Signed-off-by: Oleksandr Tyshchenko <oleksandr.tyshchenko@xxxxxxxxxxxxxxx>
>> CC: Julien Grall <julien.grall@xxxxxxxxxx>
>> ---
>>  xen/arch/arm/setup.c   |  6 +++--
>>  xen/arch/arm/time.c    | 62 
>> ++++++++++++++++++++++++++++++--------------------
>>  xen/include/xen/time.h |  1 +
>>  3 files changed, 42 insertions(+), 27 deletions(-)
>>
>> diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
>> index f49569d..a916ca6 100644
>> --- a/xen/arch/arm/setup.c
>> +++ b/xen/arch/arm/setup.c
>> @@ -743,6 +743,10 @@ void __init start_xen(unsigned long boot_phys_offset,
>>
>>      init_IRQ();
>>
>> +    platform_init();
>> +
>> +    preinit_xen_time();
>> +
>>      dt_uart_init();
>>      console_init_preirq();
>>      console_init_ring();
>> @@ -751,8 +755,6 @@ void __init start_xen(unsigned long boot_phys_offset,
>>
>>      processor_id();
>>
>> -    platform_init();
>> -
>>      smp_init_cpus();
>>      cpus = smp_get_max_cpus();
>>
>> diff --git a/xen/arch/arm/time.c b/xen/arch/arm/time.c
>> index 0add494..d442e61 100644
>> --- a/xen/arch/arm/time.c
>> +++ b/xen/arch/arm/time.c
>> @@ -61,17 +61,17 @@ unsigned int timer_get_irq(enum timer_ppi ppi)
>>      return muldiv64(ns, 1000 * cpu_khz, SECONDS(1));
>>  }
>>
>> -/* Set up the timer on the boot CPU */
>> -int __init init_xen_time(void)
>> +static const struct dt_device_match timer_ids[] __initconst =
>> +{
>> +     DT_MATCH_TIMER,
>> +     { /* sentinel */ },
>> +};
>> +
>> +/* Set up the timer on the boot CPU (early init function) */
>> +void __init preinit_xen_time(void)
>>  {
>> -    static const struct dt_device_match timer_ids[] __initconst =
>> -    {
>> -        DT_MATCH_TIMER,
>> -        { /* sentinel */ },
>> -    };
>>      struct dt_device_node *dev;
>>      int res;
>> -    unsigned int i;
>>      u32 rate;
>>
>>      dev = dt_find_matching_node(NULL, timer_ids);
>> @@ -80,6 +80,30 @@ int __init init_xen_time(void)
>>
>>      dt_device_set_used_by(dev, DOMID_XEN);
>>
>> +    res = platform_init_time();
>> +    if ( res )
>> +        panic("Timer: Cannot initialize platform timer");
>> +
>> +    res = dt_property_read_u32(dev, "clock-frequency", &rate);
>> +    if ( res )
>> +        cpu_khz = rate / 1000;
>> +    else
>> +        cpu_khz = READ_SYSREG32(CNTFRQ_EL0) / 1000;
>> +
>> +    boot_count = READ_SYSREG64(CNTPCT_EL0);
>> +}
>> +
>> +/* Set up the timer on the boot CPU (late init function) */
>> +int __init init_xen_time(void)
>> +{
>> +    struct dt_device_node *dev;
>> +    int res;
>> +    unsigned int i;
>> +
>> +    dev = dt_find_matching_node(NULL, timer_ids);
>> +    if ( !dev )
>> +        panic("Unable to find a compatible timer in the device tree");
>> +
>>      /* Retrieve all IRQs for the timer */
>>      for ( i = TIMER_PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++ )
>>      {
>> @@ -90,27 +114,15 @@ int __init init_xen_time(void)
>>          timer_irq[i] = res;
>>      }
>>
>> -    printk("Generic Timer IRQ: phys=%u hyp=%u virt=%u\n",
>> -           timer_irq[TIMER_PHYS_NONSECURE_PPI],
>> -           timer_irq[TIMER_HYP_PPI],
>> -           timer_irq[TIMER_VIRT_PPI]);
>> -
>> -    res = platform_init_time();
>> -    if ( res )
>> -        panic("Timer: Cannot initialize platform timer");
>> -
>>      /* Check that this CPU supports the Generic Timer interface */
>>      if ( !cpu_has_gentimer )
>>          panic("CPU does not support the Generic Timer v1 interface");
>>
>> -    res = dt_property_read_u32(dev, "clock-frequency", &rate);
>> -    if ( res )
>> -        cpu_khz = rate / 1000;
>> -    else
>> -        cpu_khz = READ_SYSREG32(CNTFRQ_EL0) / 1000;
>> -
>> -    boot_count = READ_SYSREG64(CNTPCT_EL0);
>> -    printk("Using generic timer at %lu KHz\n", cpu_khz);
>> +    printk("Generic Timer IRQ: phys=%u hyp=%u virt=%u Freq: %lu KHz\n",
>> +           timer_irq[TIMER_PHYS_NONSECURE_PPI],
>> +           timer_irq[TIMER_HYP_PPI],
>> +           timer_irq[TIMER_VIRT_PPI],
>> +           cpu_khz);
>>
>>      return 0;
>>  }
>> diff --git a/xen/include/xen/time.h b/xen/include/xen/time.h
>> index 709501f..bb6259d 100644
>> --- a/xen/include/xen/time.h
>> +++ b/xen/include/xen/time.h
>> @@ -12,6 +12,7 @@
>>  #include <public/xen.h>
>>
>>  extern int init_xen_time(void);
>> +void preinit_xen_time(void);
>>  extern void cstate_restore_tsc(void);
>>
>>  extern unsigned long cpu_khz;
>
>



-- 

Oleksandr Tyshchenko | Embedded Dev
GlobalLogic
www.globallogic.com

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