Subject: [PATCH v2 6/6] irqchip: gicv3: skip ITS init when no ITS available

From: [email-masked] (Yun Wu (Abel))
Date: Mon, 16 Feb 2015 22:57:39 +0800

Hi Murzin,
On 2015/2/16 18:05, Vladimir Murzin wrote:

> Hi Yun,
> 
> On 15/02/15 09:32, Yun Wu wrote:
>> There is one more condition that needs to be considered when judging
>> whether LPI feature is enabled or not, which is whether there is any
>> ITS available and correctly enabled.
>>
>> This patch will fix this by caching ITS enabling status in the GIC
>> chip data structure.
> 
> I posted patch for that before [1] and it landed in Marc's tree
> (irq/gic-fixes). It is not clear from the commit message what the "one
> more condition" is, but I guess it is the same dts stuff. Do you see
> issue without your patch applied?

Oh yes, your patch perfectly solved this problem, so this one is no longer
needed. And sorry for not noticing your patch. :)

Thanks,
	Abel

> 
> [1]
> http://lists.infradead.org/pipermail/linux-arm-kernel/2015-January/314752.html
> 
> Thanks
> Vladimir
> 
>>
>> Signed-off-by: Yun Wu <[email-masked]>
>> ---
>>  drivers/irqchip/irq-gic-v3.c | 18 +++++++++---------
>>  1 file changed, 9 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
>> index 1a146cc..e17faca 100644
>> --- a/drivers/irqchip/irq-gic-v3.c
>> +++ b/drivers/irqchip/irq-gic-v3.c
>> @@ -47,6 +47,7 @@ struct gic_chip_data {
>>  	u64			redist_stride;
>>  	u32			nr_redist_regions;
>>  	unsigned int		irq_nr;
>> +	int			lpi_enabled;
>>  };
>>
>>  static struct gic_chip_data gic_data __read_mostly;
>> @@ -390,11 +391,6 @@ static void gic_cpu_sys_reg_init(void)
>>  	gic_write_grpen1(1);
>>  }
>>
>> -static int gic_dist_supports_lpis(void)
>> -{
>> -	return !!(readl_relaxed(gic_data.dist_base + GICD_TYPER) & GICD_TYPER_LPIS);
>> -}
>> -
>>  static void gic_cpu_init(void)
>>  {
>>  	void __iomem *rbase;
>> @@ -410,7 +406,7 @@ static void gic_cpu_init(void)
>>  	gic_cpu_config(rbase, gic_redist_wait_for_rwp);
>>
>>  	/* Give LPIs a spin */
>> -	if (IS_ENABLED(CONFIG_ARM_GIC_V3_ITS) && gic_dist_supports_lpis())
>> +	if (gic_data.lpi_enabled)
>>  		its_cpu_init();
>>
>>  	/* initialise system registers */
>> @@ -629,7 +625,7 @@ static int gic_irq_domain_map(struct irq_domain *d, unsigned int irq,
>>  	}
>>  	/* LPIs */
>>  	if (hw >= 8192 && hw < GIC_ID_NR) {
>> -		if (!gic_dist_supports_lpis())
>> +		if (!gic_data.lpi_enabled)
>>  			return -EPERM;
>>  		irq_domain_set_info(d, irq, hw, &gic_chip, d->host_data,
>>  				    handle_fasteoi_irq, NULL, NULL);
>> @@ -785,8 +781,12 @@ static int __init gic_of_init(struct device_node *node, struct device_node *pare
>>
>>  	set_handle_irq(gic_handle_irq);
>>
>> -	if (IS_ENABLED(CONFIG_ARM_GIC_V3_ITS) && gic_dist_supports_lpis())
>> -		its_init(node, &gic_data.rdists, gic_data.domain);
>> +	if (IS_ENABLED(CONFIG_ARM_GIC_V3_ITS) &&
>> +	    !!(readl_relaxed(dist_base + GICD_TYPER) & GICD_TYPER_LPIS) &&
>> +	    !its_init(node, &gic_data.rdists, gic_data.domain))
>> +		gic_data.lpi_enabled = 1;
>> +	else
>> +		gic_data.lpi_enabled = 0;
>>
>>  	gic_smp_init();
>>  	gic_dist_init();
>> --
>> 1.8.0
>>