Re: [patch V4 05/14] PCI/MSI: Use guard(msi_desc_lock) where applicable

[Bjorn Helgaas]

On Wed, Mar 19, 2025 at 11:56:47AM +0100, Thomas Gleixner wrote:
> Convert the trivial cases of msi_desc_lock/unlock() pairs.
> 
> No functional change.
> 
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>

> ---
> V4: Split out from the previous combo patch
> ---
>  drivers/pci/msi/api.c |    6 ++----
>  drivers/pci/msi/msi.c |   12 ++++++------
>  2 files changed, 8 insertions(+), 10 deletions(-)
> 
> --- a/drivers/pci/msi/api.c
> +++ b/drivers/pci/msi/api.c
> @@ -53,10 +53,9 @@ void pci_disable_msi(struct pci_dev *dev
>  	if (!pci_msi_enabled() || !dev || !dev->msi_enabled)
>  		return;
>  
> -	msi_lock_descs(&dev->dev);
> +	guard(msi_descs_lock)(&dev->dev);
>  	pci_msi_shutdown(dev);
>  	pci_free_msi_irqs(dev);
> -	msi_unlock_descs(&dev->dev);
>  }
>  EXPORT_SYMBOL(pci_disable_msi);
>  
> @@ -196,10 +195,9 @@ void pci_disable_msix(struct pci_dev *de
>  	if (!pci_msi_enabled() || !dev || !dev->msix_enabled)
>  		return;
>  
> -	msi_lock_descs(&dev->dev);
> +	guard(msi_descs_lock)(&dev->dev);
>  	pci_msix_shutdown(dev);
>  	pci_free_msi_irqs(dev);
> -	msi_unlock_descs(&dev->dev);
>  }
>  EXPORT_SYMBOL(pci_disable_msix);
>  
> --- a/drivers/pci/msi/msi.c
> +++ b/drivers/pci/msi/msi.c
> @@ -871,13 +871,13 @@ void __pci_restore_msix_state(struct pci
>  
>  	write_msg = arch_restore_msi_irqs(dev);
>  
> -	msi_lock_descs(&dev->dev);
> -	msi_for_each_desc(entry, &dev->dev, MSI_DESC_ALL) {
> -		if (write_msg)
> -			__pci_write_msi_msg(entry, &entry->msg);
> -		pci_msix_write_vector_ctrl(entry, entry->pci.msix_ctrl);
> +	scoped_guard (msi_descs_lock, &dev->dev) {
> +		msi_for_each_desc(entry, &dev->dev, MSI_DESC_ALL) {
> +			if (write_msg)
> +				__pci_write_msi_msg(entry, &entry->msg);
> +			pci_msix_write_vector_ctrl(entry, entry->pci.msix_ctrl);
> +		}
>  	}
> -	msi_unlock_descs(&dev->dev);
>  
>  	pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_MASKALL, 0);
>  }
>