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

[Will Deacon]

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.

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;