Re: [powerpc][next-20210727] Boot failure - kernel BUG at arch/powerpc/kernel/interrupt.c:98!

[Nathan Chancellor <nathan@kernel.org>]

On 7/29/2021 9:35 AM, Konrad Rzeszutek Wilk wrote:
> On Thu, Jul 29, 2021 at 05:13:36PM +0100, Will Deacon wrote:
>> On Wed, Jul 28, 2021 at 10:35:34AM -0700, Nathan Chancellor wrote:
>>> On Wed, Jul 28, 2021 at 01:31:06PM +0530, Sachin Sant wrote:
>>>> next-20210723 was good. The boot failure seems to have been introduced with next-20210726.
>>>>
>>>> I have attached the boot log.
>>>
>>> I noticed this with OpenSUSE's ppc64le config [1] and my bisect landed on
>>> commit ad6c00283163 ("swiotlb: Free tbl memory in swiotlb_exit()"). That
>>> series just keeps on giving...
> 
> Low-level across platform do that. And thank you for testing it and
> finding this bug. Please let me know if the patch works so I can add it
> in in the patch series.

That was not meant to sound as sarcastic as it did so my apologies for 
that :(

Will's patch looks good to me in QEMU, I do not have a bare metal POWER 
system to test it on.

Tested-by: Nathan Chancellor <nathan@kernel.org>

>>
>> Yes, but look how handy our new print is!
> 
> :)
>>
>> [    0.010799] software IO TLB: tearing down default memory pool
>> [    0.010805] ------------[ cut here ]------------
>> [    0.010808] kernel BUG at arch/powerpc/kernel/interrupt.c:98!
>>
>> Following Nick's suggestion, the diff below should help? I don't have a
>> relevant box on which I can test it though.
>>
>> Will
>>
>> --->8
>>
>> diff --git a/arch/powerpc/platforms/pseries/svm.c b/arch/powerpc/platforms/pseries/svm.c
>> index 1d829e257996..87f001b4c4e4 100644
>> --- a/arch/powerpc/platforms/pseries/svm.c
>> +++ b/arch/powerpc/platforms/pseries/svm.c
>> @@ -63,6 +63,9 @@ void __init svm_swiotlb_init(void)
>>   
>>   int set_memory_encrypted(unsigned long addr, int numpages)
>>   {
>> +       if (!mem_encrypt_active())
>> +               return 0;
>> +
>>          if (!PAGE_ALIGNED(addr))
>>                  return -EINVAL;
>>   
>> @@ -73,6 +76,9 @@ int set_memory_encrypted(unsigned long addr, int numpages)
>>   
>>   int set_memory_decrypted(unsigned long addr, int numpages)
>>   {
>> +       if (!mem_encrypt_active())
>> +               return 0;
>> +
>>          if (!PAGE_ALIGNED(addr))
>>                  return -EINVAL;
>>