Re: [PATCH] PCI: export and use pci_msi_get_hwirq in pci-hyperv.c

From: Rob Herring <robh@kernel.org>
To: Wei Liu <wei.liu@kernel.org>
Cc: linux-pci@vger.kernel.org, linux-hyperv@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org, "K. Y. Srinivasan" <kys@microsoft.com>,
	Haiyang Zhang <haiyangz@microsoft.com>,
	Stephen Hemminger <sthemmin@microsoft.com>,
	Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
	Andrew Murray <amurray@thegoodpenguin.co.uk>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Allison Randal <allison@lohutok.net>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Enrico Weigelt <info@metux.net>
Subject: Re: [PATCH] PCI: export and use pci_msi_get_hwirq in pci-hyperv.c
Date: Thu, 7 May 2020 15:58:31 -0500	[thread overview]
Message-ID: <20200507205831.GA30988@bogus> (raw)
In-Reply-To: <20200422195818.35489-1-wei.liu@kernel.org>

On Wed, Apr 22, 2020 at 07:58:15PM +0000, Wei Liu wrote:
> There is a functionally identical function in pci-hyperv.c. Drop it and
> use pci_msi_get_hwirq instead.
> 
> This requires exporting pci_msi_get_hwirq and declaring it in msi.h.
> 
> No functional change intended.
> 
> Signed-off-by: Wei Liu <wei.liu@kernel.org>
> ---
>  arch/x86/include/asm/msi.h          | 4 ++++
>  arch/x86/kernel/apic/msi.c          | 5 +++--
>  drivers/pci/controller/pci-hyperv.c | 8 +-------
>  3 files changed, 8 insertions(+), 9 deletions(-)

Would be better if done in a way to remove an x86 dependency. 

I guess this would do it:

#define pci_msi_get_hwirq NULL

when GENERIC_MSI_DOMAIN_OPS is enabled.

> 
> diff --git a/arch/x86/include/asm/msi.h b/arch/x86/include/asm/msi.h
> index 25ddd0916bb2..353b80122b2e 100644
> --- a/arch/x86/include/asm/msi.h
> +++ b/arch/x86/include/asm/msi.h
> @@ -11,4 +11,8 @@ int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
>  
>  void pci_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc);
>  
> +struct msi_domain_info;
> +irq_hw_number_t pci_msi_get_hwirq(struct msi_domain_info *info,
> +				  msi_alloc_info_t *arg);
> +
>  #endif /* _ASM_X86_MSI_H */
> diff --git a/arch/x86/kernel/apic/msi.c b/arch/x86/kernel/apic/msi.c
> index 159bd0cb8548..56dcdd912564 100644
> --- a/arch/x86/kernel/apic/msi.c
> +++ b/arch/x86/kernel/apic/msi.c
> @@ -204,11 +204,12 @@ void native_teardown_msi_irq(unsigned int irq)
>  	irq_domain_free_irqs(irq, 1);
>  }
>  
> -static irq_hw_number_t pci_msi_get_hwirq(struct msi_domain_info *info,
> -					 msi_alloc_info_t *arg)
> +irq_hw_number_t pci_msi_get_hwirq(struct msi_domain_info *info,
> +				  msi_alloc_info_t *arg)
>  {
>  	return arg->msi_hwirq;
>  }
> +EXPORT_SYMBOL_GPL(pci_msi_get_hwirq);
>  
>  int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
>  		    msi_alloc_info_t *arg)
> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> index e6020480a28b..2b4a6452095f 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -1520,14 +1520,8 @@ static struct irq_chip hv_msi_irq_chip = {
>  	.irq_unmask		= hv_irq_unmask,
>  };
>  
> -static irq_hw_number_t hv_msi_domain_ops_get_hwirq(struct msi_domain_info *info,
> -						   msi_alloc_info_t *arg)
> -{
> -	return arg->msi_hwirq;
> -}
> -
>  static struct msi_domain_ops hv_msi_ops = {
> -	.get_hwirq	= hv_msi_domain_ops_get_hwirq,
> +	.get_hwirq	= pci_msi_get_hwirq,
>  	.msi_prepare	= pci_msi_prepare,
>  	.set_desc	= pci_msi_set_desc,
>  	.msi_free	= hv_msi_free,
> -- 
> 2.20.1
> 