Re: MIPS : die at free_initmem() function 3.9+

[David Daney <ddaney.cavm@gmail.com>]

On 05/07/2013 09:46 AM, Jiang Liu wrote:
> Hi Eunsong,
> 	Thanks for your help. I have done some code inspection and have
> found a possible reason for this issue. It seems that virt_to_page()
> can't be used to handle address in compatible segments due to following
> definitions.

This has caused multiple problems in the past.  I wrote a patch to 
correct this problem, but it looks like it was never applied.

I just sent the patch to you guys as a separate e-mail.

David Daney



>
> #define virt_to_page(kaddr)     pfn_to_page(PFN_DOWN(virt_to_phys(kaddr)))
> static inline unsigned long virt_to_phys(volatile const void *address)
> {
>          return (unsigned long)address - PAGE_OFFSET + PHYS_OFFSET;
> }
> #define __va(x)         ((void *)((unsigned long)(x) + PAGE_OFFSET - PHYS_OFFSET))
> #define __pa_symbol(x)  __pa(RELOC_HIDE((unsigned long)(x), 0))
> #define __pa(x)                                                         \
> ({                                                                      \
>      unsigned long __x = (unsigned long)(x);                             \
>      __x < CKSEG0 ? XPHYSADDR(__x) : CPHYSADDR(__x);                     \
> })
>
> #define CPHYSADDR(a)            ((_ACAST32_(a)) & 0x1fffffff)
> #define XPHYSADDR(a)            ((_ACAST64_(a)) &                       \
>                                   _CONST64_(0x000000ffffffffff))
>
> #define XKUSEG                  _CONST64_(0x0000000000000000)
> #define XKSSEG                  _CONST64_(0x4000000000000000)
> #define XKPHYS                  _CONST64_(0x8000000000000000)
> #define XKSEG                   _CONST64_(0xc000000000000000)
> #define CKSEG0                  _CONST64_(0xffffffff80000000)
> #define CKSEG1                  _CONST64_(0xffffffffa0000000)
> #define CKSSEG                  _CONST64_(0xffffffffc0000000)
> #define CKSEG3                  _CONST64_(0xffffffffe0000000)
>
> So could you please help to prepare a formal patch for this bug and send
> it to Andrew Morton for v3.10-rc1? Otherwise I could help to it too.
>
> Regards!
> Gerry
>
>
> =On 05/06/2013 06:39 AM, EUNBONG SONG wrote:
>>
>>> So on 64bits MIPS platforms, __va(__pa(x)) may not equal to x, that may cause
>>> trouble to free_initmem_default(). Could you please help to do another test
>>> by changing
>>> free_initmem_default(POISON_FREE_INITMEM);
>>> to
>>> free_initmem_default(0);
>>
>>> This test could help to identify whether this panic is caused by
>>> memset((void *)pos, poison, PAGE_SIZE);
>>> in function free_reserved_area().
>>
>> Hello, as you said i changed  "free_initmem_default(POISON_FREE_INITMEM);" to
>> "free_initmem_default(0);". Panic still occurred.
>> Actually, i put the some debug messages. and i confirmed panic occurs in __free_reserved_page() function.
>> Thanks!
>>
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>>
>
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