[Bug 203125] Kernel 5.1-rc1 fails to boot on a PowerMac G4 3,6: Caused by (from SRR1=141020): Transfer error ack signal

[Christophe Leroy]

On 05/09/2019 10:05 AM, bugzilla-daemon at bugzilla.kernel.org wrote:
> https://bugzilla.kernel.org/show_bug.cgi?id=203125
> 
> Christophe Leroy (christophe.leroy at c-s.fr) changed:
> 
>             What    |Removed                     |Added
> ----------------------------------------------------------------------------
>                   CC|                            |christophe.leroy at c-s.fr
> 
> --- Comment #5 from Christophe Leroy (christophe.leroy at c-s.fr) ---
> Apparently, MSR DR is not sent and DAR has value 0xc0090654, meaning that a
> virt address tries to get accessed while in real mode.
> 

Could you try the patch below:

diff --git a/arch/powerpc/mm/book3s32/hash_low.S 
b/arch/powerpc/mm/book3s32/hash_low.S
index e27792d0b744..8366c2abeafc 100644
--- a/arch/powerpc/mm/book3s32/hash_low.S
+++ b/arch/powerpc/mm/book3s32/hash_low.S
@@ -539,7 +539,8 @@ _GLOBAL(flush_hash_pages)
  #ifdef CONFIG_SMP
  	lis	r9, (mmu_hash_lock - PAGE_OFFSET)@ha
  	addi	r9, r9, (mmu_hash_lock - PAGE_OFFSET)@l
-	lwz	r8,TASK_CPU(r2)
+	tophys	(r8, r2)
+	lwz	r8, TASK_CPU(r8)
  	oris	r8,r8,9
  10:	lwarx	r0,0,r9
  	cmpi	0,r0,0


Christophe