On Mon, 2020-09-07 at 11:20 +0200, Christophe Leroy wrote: > > Le 05/09/2020 à 19:43, Nicholas Piggin a écrit : > > Make interrupt handlers all just take the pt_regs * argument and load > > DAR/DSISR etc from that. Make those that return a value return long. > > I like this, it will likely simplify a bit the VMAP_STACK mess. > > Not sure it is that easy. My board is stuck after the start of init. > > > On the 8xx, on Instruction TLB Error exception, we do > > andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */ > > On book3s/32, on ISI exception we do: > andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */ > > On 40x and bookE, on ISI exception we do: > li r5,0 /* Pass zero as arg3 */ > > > And regs->dsisr will just contain nothing > > So it means we should at least write back r5 into regs->dsisr from there > ? The performance impact should be minimal as we already write _DAR so > the cache line should already be in the cache. > > A hacky 'stw r5, _DSISR(r1)' in handle_page_fault() does the trick, > allthough we don't want to do it for both ISI and DSI at the end, so > you'll have to do it in every head_xxx.S
To get you series build and work, I did the following hacks: diff --git a/arch/powerpc/include/asm/interrupt.h b/arch/powerpc/include/asm/interrupt.h index acfcc7d5779b..c11045d3113a 100644 --- a/arch/powerpc/include/asm/interrupt.h +++ b/arch/powerpc/include/asm/interrupt.h @@ -93,7 +93,9 @@ static inline void interrupt_nmi_exit_prepare(struct pt_regs *regs, struct inter { nmi_exit(); +#ifdef CONFIG_PPC64 this_cpu_set_ftrace_enabled(state->ftrace_enabled); +#endif #ifdef CONFIG_PPC_BOOK3S_64 /* Check we didn't change the pending interrupt mask. */ diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index f4d0af8e1136..66f7adbe1076 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -663,6 +663,7 @@ ppc_swapcontext: */ .globl handle_page_fault handle_page_fault: + stw r5,_DSISR(r1) addi r3,r1,STACK_FRAME_OVERHEAD #ifdef CONFIG_PPC_BOOK3S_32 andis. r0,r5,DSISR_DABRMATCH@h --- Christophe