[PATCH 03/10] powerpc/64e/interrupt: use new interrupt return

[Nicholas Piggin]

Excerpts from Christophe Leroy's message of March 15, 2021 11:30 pm:
> 
> 
> Le 15/03/2021 à 04:17, Nicholas Piggin a écrit :
>> Update the new C and asm interrupt return code to account for 64e
>> specifics, switch over to use it.
>> 
>> The now-unused old ret_from_except code, that was moved to 64e after the
>> 64s conversion, is removed.
>> 
>> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
>> ---
>>   arch/powerpc/include/asm/asm-prototypes.h |   2 -
>>   arch/powerpc/kernel/entry_64.S            |   9 +-
>>   arch/powerpc/kernel/exceptions-64e.S      | 321 ++--------------------
>>   arch/powerpc/kernel/interrupt.c           |  27 +-
>>   arch/powerpc/kernel/irq.c                 |  76 -----
>>   5 files changed, 56 insertions(+), 379 deletions(-)
>> 
>> diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
>> index fbabb49888d3..ae7b058b2970 100644
>> --- a/arch/powerpc/kernel/interrupt.c
>> +++ b/arch/powerpc/kernel/interrupt.c
>> @@ -235,6 +235,10 @@ static notrace void booke_load_dbcr0(void)
>>   #endif
>>   }
>>   
>> +/* temporary hack for context tracking, removed in later patch */
>> +#include <linux/sched/debug.h>
>> +asmlinkage __visible void __sched schedule_user(void);
>> +
>>   /*
>>    * This should be called after a syscall returns, with r3 the return value
>>    * from the syscall. If this function returns non-zero, the system call
>> @@ -292,7 +296,11 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
>>   	while (unlikely(ti_flags & (_TIF_USER_WORK_MASK & ~_TIF_RESTORE_TM))) {
>>   		local_irq_enable();
>>   		if (ti_flags & _TIF_NEED_RESCHED) {
>> +#ifdef CONFIG_PPC_BOOK3E_64
>> +			schedule_user();
>> +#else
>>   			schedule();
>> +#endif
>>   		} else {
>>   			/*
>>   			 * SIGPENDING must restore signal handler function
>> @@ -360,7 +368,6 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
>>   	return ret;
>>   }
>>   
>> -#ifndef CONFIG_PPC_BOOK3E_64 /* BOOK3E not yet using this */
>>   notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned long msr)
>>   {
>>   	unsigned long ti_flags;
>> @@ -372,7 +379,9 @@ notrace unsigned long interrupt_exit_user_prepare(struct pt_regs *regs, unsigned
>>   	BUG_ON(!(regs->msr & MSR_PR));
>>   	BUG_ON(!FULL_REGS(regs));
>>   	BUG_ON(arch_irq_disabled_regs(regs));
>> +#ifdef CONFIG_PPC_BOOK3S_64
> 
> Shouldn't this go away in patch 6 as well ?
> Or is that needed at all ? In syscall_exit_prepare() it is not ifdefed .

Hmm, not sure. I'll take a look. It probably shouldn't be ifdefed at all 
but definitely by the end it should run without warning.

Thanks,
Nick