Re: [PATCH 1/5] pci: add a pci_msix_desc_addr helper

[Alexander Gordeev <agordeev@redhat.com>]

On Tue, Jul 12, 2016 at 06:20:14PM +0900, Christoph Hellwig wrote:
> To factor out the calculation of the base address for a given MSI-X vector.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/pci/msi.c | 17 +++++++++--------
>  1 file changed, 9 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
> index a080f44..0d94fbf 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -207,6 +207,12 @@ static void msi_mask_irq(struct msi_desc *desc, u32 mask, u32 flag)
>  	desc->masked = __pci_msi_desc_mask_irq(desc, mask, flag);
>  }
>  
> +static void __iomem *pci_msix_desc_addr(struct msi_desc *desc)
> +{
> +	return desc->mask_base +
> +		desc->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
> +}
> +
>  /*
>   * This internal function does not flush PCI writes to the device.
>   * All users must ensure that they read from the device before either
> @@ -217,8 +223,6 @@ static void msi_mask_irq(struct msi_desc *desc, u32 mask, u32 flag)
>  u32 __pci_msix_desc_mask_irq(struct msi_desc *desc, u32 flag)
>  {
>  	u32 mask_bits = desc->masked;
> -	unsigned offset = desc->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
> -						PCI_MSIX_ENTRY_VECTOR_CTRL;
>  
>  	if (pci_msi_ignore_mask)
>  		return 0;
> @@ -226,7 +230,7 @@ u32 __pci_msix_desc_mask_irq(struct msi_desc *desc, u32 flag)
>  	mask_bits &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;
>  	if (flag)
>  		mask_bits |= PCI_MSIX_ENTRY_CTRL_MASKBIT;
> -	writel(mask_bits, desc->mask_base + offset);
> +	writel(mask_bits, pci_msix_desc_addr(desc) + PCI_MSIX_ENTRY_VECTOR_CTRL);
>  
>  	return mask_bits;
>  }
> @@ -284,8 +288,7 @@ void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
>  	BUG_ON(dev->current_state != PCI_D0);
>  
>  	if (entry->msi_attrib.is_msix) {
> -		void __iomem *base = entry->mask_base +
> -			entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
> +		void __iomem *base = pci_msix_desc_addr(entry);
>  
>  		msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR);
>  		msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR);
> @@ -315,9 +318,7 @@ void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
>  	if (dev->current_state != PCI_D0) {
>  		/* Don't touch the hardware now */
>  	} else if (entry->msi_attrib.is_msix) {
> -		void __iomem *base;
> -		base = entry->mask_base +
> -			entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
> +		void __iomem *base = pci_msix_desc_addr(entry);
>  
>  		writel(msg->address_lo, base + PCI_MSIX_ENTRY_LOWER_ADDR);
>  		writel(msg->address_hi, base + PCI_MSIX_ENTRY_UPPER_ADDR);
> -- 
> 2.1.4
> 
Reviewed-by: Alexander Gordeev <agordeev@redhat.com>