[PATCH v2 4/8] powerpc/xive: Simplify xive_core_debug_show()

[Cédric Le Goater]

On 3/9/21 10:42 AM, Greg Kurz wrote:
> On Tue, 9 Mar 2021 10:13:39 +0100
> Greg Kurz <groug at kaod.org> wrote:
> 
>> On Mon, 8 Mar 2021 19:11:11 +0100
>> Cédric Le Goater <clg at kaod.org> wrote:
>>
>>> On 3/8/21 7:07 PM, Greg Kurz wrote:
>>>> On Wed, 3 Mar 2021 18:48:53 +0100
>>>> Cédric Le Goater <clg at kaod.org> wrote:
>>>>
>>>>> Now that the IPI interrupt has its own domain, the checks on the HW
>>>>> interrupt number XIVE_IPI_HW_IRQ and on the chip can be replaced by a
>>>>> check on the domain.
>>>>>
>>>>> Signed-off-by: Cédric Le Goater <clg at kaod.org>
>>>>> ---
>>>>
>>>> Shouldn't this have the following tags ?
>>>>
>>>> Reported-by: kernel test robot <lkp at intel.com>
>>>> Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
>>>> Fixes: 930914b7d528 ("powerpc/xive: Add a debugfs file to dump internal XIVE state")
>>>
>>> The next patch has because it removes the useless check on irq_data.
>>>  
>>
>> Ok I get it. This report isn't about an actual crash. Just a false
>> positive because of the not needed check in the caller.
>>
> 
> Hrm... I meant because of the check in xive_debug_show_irq(). On the
> contrary, the check removed by this patch in xive_core_debug_show()
> was rather an explicit hint that xive_debug_show_irq() couldn't be
> called with d being NULL.

yes. irq_desc_get_irq_data() does not return a NULL value and 
xive_debug_show_irq() is only called from the for_each_irq_desc()
loop. 


C.


> 
>>> C.
>>>
>>>>
>>>> Anyway,
>>>>
>>>> Reviewed-by: Greg Kurz <groug at kaod.org>
>>>>
>>>>>  arch/powerpc/sysdev/xive/common.c | 18 ++++--------------
>>>>>  1 file changed, 4 insertions(+), 14 deletions(-)
>>>>>
>>>>> diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
>>>>> index 678680531d26..7581cb12bb53 100644
>>>>> --- a/arch/powerpc/sysdev/xive/common.c
>>>>> +++ b/arch/powerpc/sysdev/xive/common.c
>>>>> @@ -1579,17 +1579,14 @@ static void xive_debug_show_cpu(struct seq_file *m, int cpu)
>>>>>  	seq_puts(m, "\n");
>>>>>  }
>>>>>  
>>>>> -static void xive_debug_show_irq(struct seq_file *m, u32 hw_irq, struct irq_data *d)
>>>>> +static void xive_debug_show_irq(struct seq_file *m, struct irq_data *d)
>>>>>  {
>>>>> -	struct irq_chip *chip = irq_data_get_irq_chip(d);
>>>>> +	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
>>>>>  	int rc;
>>>>>  	u32 target;
>>>>>  	u8 prio;
>>>>>  	u32 lirq;
>>>>>  
>>>>> -	if (!is_xive_irq(chip))
>>>>> -		return;
>>>>> -
>>>>>  	rc = xive_ops->get_irq_config(hw_irq, &target, &prio, &lirq);
>>>>>  	if (rc) {
>>>>>  		seq_printf(m, "IRQ 0x%08x : no config rc=%d\n", hw_irq, rc);
>>>>> @@ -1627,16 +1624,9 @@ static int xive_core_debug_show(struct seq_file *m, void *private)
>>>>>  
>>>>>  	for_each_irq_desc(i, desc) {
>>>>>  		struct irq_data *d = irq_desc_get_irq_data(desc);
>>>>> -		unsigned int hw_irq;
>>>>> -
>>>>> -		if (!d)
>>>>> -			continue;
>>>>> -
>>>>> -		hw_irq = (unsigned int)irqd_to_hwirq(d);
>>>>>  
>>>>> -		/* IPIs are special (HW number 0) */
>>>>> -		if (hw_irq != XIVE_IPI_HW_IRQ)
>>>>> -			xive_debug_show_irq(m, hw_irq, d);
>>>>> +		if (d->domain == xive_irq_domain)
>>>>> +			xive_debug_show_irq(m, d);
>>>>>  	}
>>>>>  	return 0;
>>>>>  }
>>>>
>>>
>>
>