[U-Boot] [PATCH v3] armv8: fsl-layerscale: Rewrite reserving memory for MC and debug server

[York Sun <yorksun@freescale.com>]

On 11/22/2015 09:53 AM, York Sun wrote:
> 
> 
> On 11/22/2015 08:11 AM, Simon Glass wrote:
>> Hi York,
>>

<snip>

>>> diff --git a/common/board_f.c b/common/board_f.c
>>> index 8061105..2fd1c21 100644
>>> --- a/common/board_f.c
>>> +++ b/common/board_f.c
>>> @@ -316,6 +316,15 @@ __weak ulong board_get_usable_ram_top(ulong total_size)
>>>         return gd->ram_top;
>>>  }
>>>
>>> +__weak phys_size_t board_reserve_ram_top(phys_size_t ram_size)
>>> +{
>>> +#ifdef CONFIG_SYS_MEM_TOP_HIDE
>>> +       return ram_size - CONFIG_SYS_MEM_TOP_HIDE;
>>> +#else
>>> +       return ram_size;
>>> +#endif
>>> +}
>>> +
>>>  static int setup_dest_addr(void)
>>>  {
>>>         debug("Monitor len: %08lX\n", gd->mon_len);
>>> @@ -332,19 +341,17 @@ static int setup_dest_addr(void)
>>>          */
>>>         gd->secure_ram = gd->ram_size;
>>>  #endif
>>> -#if defined(CONFIG_SYS_MEM_TOP_HIDE)
>>>         /*
>>>          * Subtract specified amount of memory to hide so that it won't
>>>          * get "touched" at all by U-Boot. By fixing up gd->ram_size
>>>          * the Linux kernel should now get passed the now "corrected"
>>> -        * memory size and won't touch it either. This should work
>>> -        * for arch/ppc and arch/powerpc. Only Linux board ports in
>>> -        * arch/powerpc with bootwrapper support, that recalculate the
>>> -        * memory size from the SDRAM controller setup will have to
>>> -        * get fixed.
>>> +        * memory size and won't touch it either. This has been used
>>> +        * by arch/powerpc exclusively. Now ARMv8 takes advantage of
>>> +        * thie mechanism. If memory is split into banks, addresses
>>> +        * need to be calculated.
>>>          */
>>> -       gd->ram_size -= CONFIG_SYS_MEM_TOP_HIDE;
>>> -#endif
>>> +       gd->ram_size = board_reserve_ram_top(gd->ram_size);
>>> +
>>>  #ifdef CONFIG_SYS_SDRAM_BASE
>>>         gd->ram_top = CONFIG_SYS_SDRAM_BASE;
>>>  #endif
>>
>> Sorry I didn't notice this patch before...
>>
>> Can you use the existing board_get_usable_ram_top() for this?
>>
> 
> Simon,
> 
> No. The "top" is not necessarily the end of memory. It is the top of
> CONFIG_SYS_SDRAM_BASE + get_effective_memsize(). I am trying to avoid reserving
> memory in the middle.
> 
> I am using the same way as CONFIG_SYS_MEM_TOP_HIDE, but rewriting it with a weak
> function.
> 

Simon,

If you are satisfied with my explanation, I am considering to merge this patch.

York