linux-kernel - Re: [RFC Part2 v1 14/21] x86, hpet: Enhance HPET IRQ to support hierarchy irqdomain

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Message-ID: <alpine.DEB.2.10.1409161104120.4247@nanos>
Date:	Tue, 16 Sep 2014 11:31:45 -0700 (PDT)
From:	Thomas Gleixner <tglx@...utronix.de>
To:	Jiang Liu <jiang.liu@...ux.intel.com>
cc:	Benjamin Herrenschmidt <benh@...nel.crashing.org>,
	Ingo Molnar <mingo@...hat.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Randy Dunlap <rdunlap@...radead.org>,
	Yinghai Lu <yinghai@...nel.org>,
	Borislav Petkov <bp@...en8.de>,
	Grant Likely <grant.likely@...aro.org>,
	Marc Zyngier <marc.zyngier@....com>,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Tony Luck <tony.luck@...el.com>,
	Joerg Roedel <joro@...tes.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	x86@...nel.org, linux-kernel@...r.kernel.org,
	linux-pci@...r.kernel.org, linux-acpi@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [RFC Part2 v1 14/21] x86, hpet: Enhance HPET IRQ to support
 hierarchy irqdomain

On Thu, 11 Sep 2014, Jiang Liu wrote:
>  #ifdef CONFIG_HPET_TIMER
> +#define	HPET_DOMAIN_REMAPPED		0x80000000
> +
> +static inline int hpet_dev_id(struct irq_domain *domain)
> +{
> +	return (int)((long)domain->host_data & ~HPET_DOMAIN_REMAPPED);
> +}
> +
> +static inline bool hpet_remapped(struct irq_domain *domain)
> +{
> +	return (bool)((long)domain->host_data & HPET_DOMAIN_REMAPPED);
> +}

It's kinda odd to have this encoded in domain->host_data.

>  static int hpet_msi_set_affinity(struct irq_data *data,
>  				 const struct cpumask *mask, bool force)
>  {
> +	struct irq_data *parent = data->parent_data;
>  	struct irq_cfg *cfg = irqd_cfg(data);
>  	struct msi_msg msg;
> -	unsigned int dest;
>  	int ret;
>  
> -	ret = apic_set_affinity(data, mask, &dest);
> -	if (ret)
> -		return ret;
> -
> -	hpet_msi_read(data->handler_data, &msg);
> -
> -	msg.data &= ~MSI_DATA_VECTOR_MASK;
> -	msg.data |= MSI_DATA_VECTOR(cfg->vector);
> -	msg.address_lo &= ~MSI_ADDR_DEST_ID_MASK;
> -	msg.address_lo |= MSI_ADDR_DEST_ID(dest);
> -
> -	hpet_msi_write(data->handler_data, &msg);
> +	ret = parent->chip->irq_set_affinity(parent, mask, force);
> +	/* No need to rewrite HPET registers if interrupt is remapped */
> +	if (ret >= 0 && !hpet_remapped(data->domain)) {

So we really should use irq_data->chip_data for this, i.e. storing

struct hpet_msi {
       struct msi_msg msg;
       bool remapped;
       /* whatever you need here */
};

> +		hpet_msi_read(data->handler_data, &msg);
> +		msg.data &= ~MSI_DATA_VECTOR_MASK;
> +		msg.data |= MSI_DATA_VECTOR(cfg->vector);
> +		msg.address_lo &= ~MSI_ADDR_DEST_ID_MASK;
> +		msg.address_lo |= MSI_ADDR_DEST_ID(cfg->dest_apicid);

We need the same thing for MSI so this should be a helper function

   msi_update_msg(struct msi_msg *msg, struct irq_cfg *cfg)

> +		hpet_msi_write(data->handler_data, &msg);
> +	}
>  
> -	return IRQ_SET_MASK_OK_NOCOPY;
> +	return ret;
>  }
 
Thanks,

	tglx
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