Re: [patch 28/39] PCI/MSI: Move pci_irq_get_affinity() to api.c

Bjorn Helgaas
2022-11-16T16:40:23Z

On Fri, Nov 11, 2022 at 02:54:59PM +0100, Thomas Gleixner wrote:
> From: Ahmed S. Darwish <darwi@linutronix.de>
>
> To distangle the maze in msi.c, all exported device-driver MSI APIs are
> now to be grouped in one file, api.c.
>
> Move pci_irq_get_affinity() and let its kernel-doc match rest of the
> file.
>
> Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

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

One nit below.

> ---
> drivers/pci/msi/api.c | 43 +++++++++++++++++++++++++++++++++++++++++++
> drivers/pci/msi/msi.c | 38 --------------------------------------
> 2 files changed, 43 insertions(+), 38 deletions(-)
> ---
> diff --git a/drivers/pci/msi/api.c b/drivers/pci/msi/api.c
> index 653a61868ae6..473df7ba0584 100644
> --- a/drivers/pci/msi/api.c
> +++ b/drivers/pci/msi/api.c
> @@ -9,6 +9,7 @@
> */
>
> #include <linux/export.h>
> +#include <linux/irq.h>
>
> #include "msi.h"
>
> @@ -251,6 +252,48 @@ int pci_irq_vector(struct pci_dev *dev, unsigned int nr)
> EXPORT_SYMBOL(pci_irq_vector);
>
> /**
> + * pci_irq_get_affinity() - Get a device interrupt vector affinity
> + * @dev: the PCI device to operate on
> + * @nr: device-relative interrupt vector index (0-based); has different
> + * meanings, depending on interrupt mode
> + * MSI-X the index in the MSI-X vector table
> + * MSI the index of the enabled MSI vectors
> + * INTx must be 0
> + *
> + * Return: MSI/MSI-X vector affinity, NULL if @nr is out of range or if
> + * the MSI(-X) vector was allocated without explicit affinity
> + * requirements (e.g., by pci_enable_msi(), pci_enable_msix_range(), or
> + * pci_alloc_irq_vectors() without the %PCI_IRQ_AFFINITY flag). Return a
> + * generic set of CPU ids representing all possible CPUs available
> + * during system boot if the device is in legacy INTx mode.

s/ids/IDs/

> + */
> +const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
> +{
> + int idx, irq = pci_irq_vector(dev, nr);
> + struct msi_desc *desc;
> +
> + if (WARN_ON_ONCE(irq <= 0))
> + return NULL;
> +
> + desc = irq_get_msi_desc(irq);
> + /* Non-MSI does not have the information handy */
> + if (!desc)
> + return cpu_possible_mask;
> +
> + /* MSI[X] interrupts can be allocated without affinity descriptor */
> + if (!desc->affinity)
> + return NULL;
> +
> + /*
> + * MSI has a mask array in the descriptor.
> + * MSI-X has a single mask.
> + */
> + idx = dev->msi_enabled ? nr : 0;
> + return &desc->affinity[idx].mask;
> +}
> +EXPORT_SYMBOL(pci_irq_get_affinity);
> +
> +/**
> * pci_free_irq_vectors() - Free previously allocated IRQs for a device
> * @dev: the PCI device to operate on
> *
> diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
> index 6fa90d07d2e4..d78646d1c116 100644
> --- a/drivers/pci/msi/msi.c
> +++ b/drivers/pci/msi/msi.c
> @@ -854,44 +854,6 @@ int __pci_enable_msix_range(struct pci_dev *dev,
> }
> }
>
> -/**
> - * pci_irq_get_affinity - return the affinity of a particular MSI vector
> - * @dev: PCI device to operate on
> - * @nr: device-relative interrupt vector index (0-based).
> - *
> - * @nr has the following meanings depending on the interrupt mode:
> - * MSI-X: The index in the MSI-X vector table
> - * MSI: The index of the enabled MSI vectors
> - * INTx: Must be 0
> - *
> - * Return: A cpumask pointer or NULL if @nr is out of range
> - */
> -const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
> -{
> - int idx, irq = pci_irq_vector(dev, nr);
> - struct msi_desc *desc;
> -
> - if (WARN_ON_ONCE(irq <= 0))
> - return NULL;
> -
> - desc = irq_get_msi_desc(irq);
> - /* Non-MSI does not have the information handy */
> - if (!desc)
> - return cpu_possible_mask;
> -
> - /* MSI[X] interrupts can be allocated without affinity descriptor */
> - if (!desc->affinity)
> - return NULL;
> -
> - /*
> - * MSI has a mask array in the descriptor.
> - * MSI-X has a single mask.
> - */
> - idx = dev->msi_enabled ? nr : 0;
> - return &desc->affinity[idx].mask;
> -}
> -EXPORT_SYMBOL(pci_irq_get_affinity);
> -
> struct pci_dev *msi_desc_to_pci_dev(struct msi_desc *desc)
> {
> return to_pci_dev(desc->dev);
>