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PCI/MSI: Provide pci_ims_alloc/free_irq()

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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@linutronix.de>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124232326.961711347@linutronix.de
This commit is contained in:
Thomas Gleixner 2022-11-25 00:26:31 +01:00
parent 0194425af0
commit c9e5bea273
2 changed files with 53 additions and 0 deletions
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50
drivers/pci/msi/api.c
View file

@ -365,6 +365,56 @@ const struct cpumask *pci_irq_get_affinity(struct pci_dev *dev, int nr)
}
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
* @icookie: Pointer to an IMS implementation specific cookie for this
* IMS instance (PASID, queue ID, pointer...).
* The cookie content is copied into the MSI descriptor for the
* interrupt chip callbacks or domain specific setup functions.
* @affdesc: Optional pointer to an interrupt affinity descriptor
*
* 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 @icookie to store the MSI message in
* the appropriate place.
*
* 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.
*/
struct msi_map pci_ims_alloc_irq(struct pci_dev *dev, union msi_instance_cookie *icookie,
const struct irq_affinity_desc *affdesc)
{
return msi_domain_alloc_irq_at(&dev->dev, MSI_SECONDARY_DOMAIN, MSI_ANY_INDEX,
affdesc, icookie);
}
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 <= 0))
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

3
include/linux/pci.h
View file

@ -2491,6 +2491,9 @@ 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_instance_cookie *icookie,
const struct irq_affinity_desc *affdesc);
void pci_ims_free_irq(struct pci_dev *pdev, struct msi_map map);
#include <linux/dma-mapping.h>