Re: PS3 early lock-up

Hi,

Benjamin Herrenschmidt wrote:

quoted

quoted

ps3_hpte_insert() seems to be called during system initialization with the
following values of rflags:
  - first call: 0x190
  - initial memory: 0x194 (455 times)
  - hotplug memory:
      o crash: 0x115
      o OK: 0x117

Do you have an idea of what's really going on?

Weird... Both look incorrect. In fact, it's a bit scary...

The one with the 7 at the end means that user space as RO access to
the segment (oops !) and supervisor too. The one with the 5 means
RO for user and RW for supervisor.

That is unless your HV is munging them in strange ways... I don't
know why LV1 is refusing a combination though.

As for the flags, it depends what htab_bolt_mapping() is called
with.

Do you have a backtrace ? I'm a bit lots in the mem hotswap code
trying to figure out where the mapping comes from..

Ah, found it... It should be ok... both the mapping of the RAM itself
and vmemmap_populate() should be passing 

  _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX;

Which should be 0x194.

That is 0x190.

0x194 = _PAGE_EXEC | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX

Can you find out where that stupid value comes from ?

I didn't have time to look at in detail, but it fails from the
ioremap call in ps3_map_htab (arch/powerpc/platfroms/ps3/htab.c):

 htab = (__force struct hash_pte *)ioremap_flags(htab_addr, htab_size,
     pgprot_val(PAGE_READONLY_X));

IIRC, lv1 doesn't allow a read/write mapping of the htab, and that is
why I used pgprot_val(PAGE_READONLY_X) here.

I guess the value returned from pgprot_val(PAGE_READONLY_X)
changed in recent kernels, and that is what is causing the failure.

Just FYI, I put these in:

  printk("%s:%d: flags = %x\n", __func__, __LINE__, (_PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX));
  printk("%s:%d: flags = %x\n", __func__, __LINE__, pgprot_val(PAGE_READONLY_X));

and got this (and lv1_write_htab_entry failed):

  ps3_map_htab:288: flags = 190
  ps3_map_htab:289: flags = 117

-Geoff