Re: [patch V2 03/36] PCI/MSI: Allocate MSI device data on first use

Bjorn Helgaas
2021-12-07T21:03:50Z

On Mon, Dec 06, 2021 at 11:39:00PM +0100, Thomas Gleixner wrote:
> Allocate MSI device data on first use, i.e. when a PCI driver invokes one
> of the PCI/MSI enablement functions.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> ---
> drivers/pci/msi/msi.c | 20 +++++++++++++++-----
> 1 file changed, 15 insertions(+), 5 deletions(-)
>
> --- a/drivers/pci/msi/msi.c
> +++ b/drivers/pci/msi/msi.c
> @@ -889,10 +889,12 @@ static int __pci_enable_msi_range(struct
> /* deprecated, don't use */
> int pci_enable_msi(struct pci_dev *dev)
> {
> - int rc = __pci_enable_msi_range(dev, 1, 1, NULL);
> - if (rc < 0)
> - return rc;
> - return 0;
> + int rc = msi_setup_device_data(&dev->dev);
> +
> + if (!rc)
> + rc = __pci_enable_msi_range(dev, 1, 1, NULL);
> +
> + return rc < 0 ? rc : 0;
> }
> EXPORT_SYMBOL(pci_enable_msi);
>
> @@ -947,7 +949,11 @@ static int __pci_enable_msix_range(struc
> int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
> int minvec, int maxvec)
> {
> - return __pci_enable_msix_range(dev, entries, minvec, maxvec, NULL, 0);
> + int ret = msi_setup_device_data(&dev->dev);
> +
> + if (!ret)
> + ret = __pci_enable_msix_range(dev, entries, minvec, maxvec, NULL, 0);
> + return ret;
> }
> EXPORT_SYMBOL(pci_enable_msix_range);
>
> @@ -974,8 +980,12 @@ int pci_alloc_irq_vectors_affinity(struc
> struct irq_affinity *affd)
> {
> struct irq_affinity msi_default_affd = {0};
> + int ret = msi_setup_device_data(&dev->dev);
> int nvecs = -ENOSPC;
>
> + if (ret)
> + return ret;
> +
> if (flags & PCI_IRQ_AFFINITY) {
> if (!affd)
> affd = &msi_default_affd;
>