On Fri, Nov 11, 2022 at 02:58:57PM +0100, Thomas Gleixner wrote:
> Single vector allocation which allocates the next free index in the IMS
> space. The free function releases.
>
> All allocated vectors are released also via pci_free_vectors() which is
> also releasing MSI/MSI-X vectors.
>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
I would probably capitalize "ID" in the function comment below, but
either way.
> ---
> drivers/pci/msi/api.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/pci.h | 3 +++
> 2 files changed, 53 insertions(+)
>
> --- a/drivers/pci/msi/api.c
> +++ b/drivers/pci/msi/api.c
> @@ -361,6 +361,56 @@ const struct cpumask *pci_irq_get_affini
> EXPORT_SYMBOL(pci_irq_get_affinity);
>
> /**
> + * pci_ims_alloc_irq - Allocate an interrupt on a PCI/IMS interrupt domain
> + * @dev: The PCI device to operate on
> + * @cookie: Pointer to an IMS implementation specific device cookie
> + * (PASID, queue id, pointer...). The cookie content is stored
> + * in the MSI descriptor for the interrupt chip callbacks or
> + * domain specific setup functions
> + * @affdesc: Optional pointer to an interrupt affinity descriptor
> + *
> + * Return: A struct msi_map
> + *
> + * On success msi_map::index contains the allocated index (>= 0) and
> + * msi_map::virq the allocated Linux interrupt number (> 0).
> + *
> + * On fail msi_map::index contains the error code and msi_map::virq
> + * is set to 0.
> + *
> + * Note: There is no index for IMS allocations as IMS is an implementation
> + * specific storage and does not have any direct associations between
> + * index, which might be a pure software construct, and device
> + * functionality. This association is established by the driver either
> + * via the index - if there is a hardware table - or in case of purely
> + * software managed IMS implementation the association happens via
> + * the irq_write_msi_msg() callback of the implementation specific
> + * interrupt chip, which utilizes the provided @cookie to store the MSI
> + * message in the appropriate place.
> + */
> +struct msi_map pci_ims_alloc_irq(struct pci_dev *dev, union msi_dev_cookie *cookie,
> + const struct irq_affinity_desc *affdesc)
> +{
> + return msi_domain_alloc_irq_at(&dev->dev, MSI_SECONDARY_DOMAIN, MSI_ANY_INDEX,
> + affdesc, cookie);
> +}
> +EXPORT_SYMBOL_GPL(pci_ims_alloc_irq);
> +
> +/**
> + * pci_ims_free_irq - Allocate an interrupt on a PCI/IMS interrupt domain
> + * which was allocated via pci_ims_alloc_irq()
> + * @dev: The PCI device to operate on
> + * @map: A struct msi_map describing the interrupt to free as
> + * returned from pci_ims_alloc_irq()
> + */
> +void pci_ims_free_irq(struct pci_dev *dev, struct msi_map map)
> +{
> + if (WARN_ON_ONCE(map.index < 0 || !map.virq))
> + return;
> + msi_domain_free_irqs_range(&dev->dev, MSI_SECONDARY_DOMAIN, map.index, map.index);
> +}
> +EXPORT_SYMBOL_GPL(pci_ims_free_irq);
> +
> +/**
> * pci_free_irq_vectors() - Free previously allocated IRQs for a device
> * @dev: the PCI device to operate on
> *
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -2485,6 +2485,9 @@ struct msi_domain_template;
>
> bool pci_create_ims_domain(struct pci_dev *pdev, const struct msi_domain_template *template,
> unsigned int hwsize, void *data);
> +struct msi_map pci_ims_alloc_irq(struct pci_dev *pdev, union msi_dev_cookie *cookie,
> + const struct irq_affinity_desc *affdesc);
> +void pci_ims_free_irq(struct pci_dev *pdev, struct msi_map map);
>
> #include <linux/dma-mapping.h>
>
>
