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

[Sachin Sant]

> On 29-Jul-2021, at 9:43 PM, Will Deacon <will at kernel.org> 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...
> 
> 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.
> 

Thanks for the fix. This fixes the reported problem for me.
Tested successfully on both PowerVM LPAR as well as bare metal environment.

Reported-by: Sachin Sant <sachinp at linux.vnet.ibm.com>
Tested-by: Sachin Sant <sachinp at linux.vnet.ibm.com>

> 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;
>