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

[Christophe Leroy]

Le 16/03/2021 à 08:25, Nicholas Piggin a écrit :
> Excerpts from Nicholas Piggin's message of March 16, 2021 5:04 pm:
>> 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.
> 
> Oh I got confused and thought that was the syscall exit. Interrupt exit
> has to keep this until patch 6 because 64e context tracking does
> everything in interrupt wrappers, so by the time we get here it will
> already be set to CONTEXT_USER.
> 

ok, but that it has to go in patch 6 ? At the time being the #ifdef is still there at the end of the 
series