Re: [patch V2 10/31] PCI/MSI: Use msi_on_each_desc()

[Bjorn Helgaas <helgaas@xxxxxxxxxx>]

On Mon, Dec 06, 2021 at 11:51:18PM +0100, Thomas Gleixner wrote:
> Use the new iterator functions which pave the way for dynamically extending
> MSI-X vectors.
> 
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>

> ---
>  drivers/pci/msi/irqdomain.c |    4 ++--
>  drivers/pci/msi/legacy.c    |   19 ++++++++-----------
>  drivers/pci/msi/msi.c       |   30 ++++++++++++++----------------
>  3 files changed, 24 insertions(+), 29 deletions(-)
> 
> --- a/drivers/pci/msi/irqdomain.c
> +++ b/drivers/pci/msi/irqdomain.c
> @@ -83,7 +83,7 @@ static int pci_msi_domain_check_cap(stru
>                                   struct msi_domain_info *info,
>                                   struct device *dev)
>  {
> -     struct msi_desc *desc = first_pci_msi_entry(to_pci_dev(dev));
> +     struct msi_desc *desc = msi_first_desc(dev, MSI_DESC_ALL);
>  
>       /* Special handling to support __pci_enable_msi_range() */
>       if (pci_msi_desc_is_multi_msi(desc) &&
> @@ -98,7 +98,7 @@ static int pci_msi_domain_check_cap(stru
>                       unsigned int idx = 0;
>  
>                       /* Check for gaps in the entry indices */
> -                     for_each_msi_entry(desc, dev) {
> +                     msi_for_each_desc(desc, dev, MSI_DESC_ALL) {
>                               if (desc->msi_index != idx++)
>                                       return -ENOTSUPP;
>                       }
> --- a/drivers/pci/msi/legacy.c
> +++ b/drivers/pci/msi/legacy.c
> @@ -28,7 +28,7 @@ int __weak arch_setup_msi_irqs(struct pc
>       if (type == PCI_CAP_ID_MSI && nvec > 1)
>               return 1;
>  
> -     for_each_pci_msi_entry(desc, dev) {
> +     msi_for_each_desc(desc, &dev->dev, MSI_DESC_NOTASSOCIATED) {
>               ret = arch_setup_msi_irq(dev, desc);
>               if (ret)
>                       return ret < 0 ? ret : -ENOSPC;
> @@ -42,27 +42,24 @@ void __weak arch_teardown_msi_irqs(struc
>       struct msi_desc *desc;
>       int i;
>  
> -     for_each_pci_msi_entry(desc, dev) {
> -             if (desc->irq) {
> -                     for (i = 0; i < desc->nvec_used; i++)
> -                             arch_teardown_msi_irq(desc->irq + i);
> -             }
> +     msi_for_each_desc(desc, &dev->dev, MSI_DESC_ASSOCIATED) {
> +             for (i = 0; i < desc->nvec_used; i++)
> +                     arch_teardown_msi_irq(desc->irq + i);
>       }
>  }
>  
>  static int pci_msi_setup_check_result(struct pci_dev *dev, int type, int ret)
>  {
> -     struct msi_desc *entry;
> +     struct msi_desc *desc;
>       int avail = 0;
>  
>       if (type != PCI_CAP_ID_MSIX || ret >= 0)
>               return ret;
>  
>       /* Scan the MSI descriptors for successfully allocated ones. */
> -     for_each_pci_msi_entry(entry, dev) {
> -             if (entry->irq != 0)
> -                     avail++;
> -     }
> +     msi_for_each_desc(desc, &dev->dev, MSI_DESC_ASSOCIATED)
> +             avail++;
> +
>       return avail ? avail : ret;
>  }
>  
> --- a/drivers/pci/msi/msi.c
> +++ b/drivers/pci/msi/msi.c
> @@ -299,7 +299,6 @@ static void __pci_restore_msix_state(str
>  
>       if (!dev->msix_enabled)
>               return;
> -     BUG_ON(list_empty(dev_to_msi_list(&dev->dev)));
>  
>       /* route the table */
>       pci_intx_for_msi(dev, 0);
> @@ -309,7 +308,7 @@ static void __pci_restore_msix_state(str
>       write_msg = arch_restore_msi_irqs(dev);
>  
>       msi_lock_descs(&dev->dev);
> -     for_each_pci_msi_entry(entry, 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);
> @@ -378,14 +377,14 @@ static int msi_verify_entries(struct pci
>       if (!dev->no_64bit_msi)
>               return 0;
>  
> -     for_each_pci_msi_entry(entry, dev) {
> +     msi_for_each_desc(entry, &dev->dev, MSI_DESC_ALL) {
>               if (entry->msg.address_hi) {
>                       pci_err(dev, "arch assigned 64-bit MSI address %#x%08x 
> but device only supports 32 bits\n",
>                               entry->msg.address_hi, entry->msg.address_lo);
> -                     return -EIO;
> +                     break;
>               }
>       }
> -     return 0;
> +     return !entry ? 0 : -EIO;
>  }
>  
>  /**
> @@ -418,7 +417,7 @@ static int msi_capability_init(struct pc
>               goto unlock;
>  
>       /* All MSIs are unmasked by default; mask them all */
> -     entry = first_pci_msi_entry(dev);
> +     entry = msi_first_desc(&dev->dev, MSI_DESC_ALL);
>       pci_msi_mask(entry, msi_multi_mask(entry));
>  
>       /* Configure MSI capability structure */
> @@ -508,11 +507,11 @@ static int msix_setup_msi_descs(struct p
>  
>  static void msix_update_entries(struct pci_dev *dev, struct msix_entry 
> *entries)
>  {
> -     struct msi_desc *entry;
> +     struct msi_desc *desc;
>  
>       if (entries) {
> -             for_each_pci_msi_entry(entry, dev) {
> -                     entries->vector = entry->irq;
> +             msi_for_each_desc(desc, &dev->dev, MSI_DESC_ALL) {
> +                     entries->vector = desc->irq;
>                       entries++;
>               }
>       }
> @@ -705,15 +704,14 @@ static void pci_msi_shutdown(struct pci_
>       if (!pci_msi_enable || !dev || !dev->msi_enabled)
>               return;
>  
> -     BUG_ON(list_empty(dev_to_msi_list(&dev->dev)));
> -     desc = first_pci_msi_entry(dev);
> -
>       pci_msi_set_enable(dev, 0);
>       pci_intx_for_msi(dev, 1);
>       dev->msi_enabled = 0;
>  
>       /* Return the device with MSI unmasked as initial states */
> -     pci_msi_unmask(desc, msi_multi_mask(desc));
> +     desc = msi_first_desc(&dev->dev, MSI_DESC_ALL);
> +     if (!WARN_ON_ONCE(!desc))
> +             pci_msi_unmask(desc, msi_multi_mask(desc));
>  
>       /* Restore dev->irq to its default pin-assertion IRQ */
>       dev->irq = desc->pci.msi_attrib.default_irq;
> @@ -789,7 +787,7 @@ static int __pci_enable_msix(struct pci_
>  
>  static void pci_msix_shutdown(struct pci_dev *dev)
>  {
> -     struct msi_desc *entry;
> +     struct msi_desc *desc;
>  
>       if (!pci_msi_enable || !dev || !dev->msix_enabled)
>               return;
> @@ -800,8 +798,8 @@ static void pci_msix_shutdown(struct pci
>       }
>  
>       /* Return the device with MSI-X masked as initial states */
> -     for_each_pci_msi_entry(entry, dev)
> -             pci_msix_mask(entry);
> +     msi_for_each_desc(desc, &dev->dev, MSI_DESC_ALL)
> +             pci_msix_mask(desc);
>  
>       pci_msix_clear_and_set_ctrl(dev, PCI_MSIX_FLAGS_ENABLE, 0);
>       pci_intx_for_msi(dev, 1);
>