include/linux/msi_api.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef LINUX_MSI_API_H
   3 #define LINUX_MSI_API_H
   4
   5 /*
   6  * APIs which are relevant for device driver code for allocating and
   7  * freeing MSI interrupts and querying the associations between
   8  * hardware/software MSI indices and the Linux interrupt number.
   9  */
  10
  11 struct device;
  12
  13 /*
  14  * Per device interrupt domain related constants.
  15  */
  16 enum msi_domain_ids {
  17         MSI_DEFAULT_DOMAIN,
  18         MSI_MAX_DEVICE_IRQDOMAINS,
  19 };
  20
  21 /**
  22  * union msi_instance_cookie - MSI instance cookie
  23  * @value:      u64 value store
  24  * @ptr:        Pointer to usage site specific data
  25  *
  26  * This cookie is handed to the IMS allocation function and stored in the
  27  * MSI descriptor for the interrupt chip callbacks.
  28  *
  29  * The content of this cookie is MSI domain implementation defined.  For
  30  * PCI/IMS implementations this could be a PASID or a pointer to queue
  31  * memory.
  32  */
  33 union msi_instance_cookie {
  34         u64     value;
  35         void    *ptr;
  36 };
  37
  38 /**
  39  * msi_map - Mapping between MSI index and Linux interrupt number
  40  * @index:      The MSI index, e.g. slot in the MSI-X table or
  41  *              a software managed index if >= 0. If negative
  42  *              the allocation function failed and it contains
  43  *              the error code.
  44  * @virq:       The associated Linux interrupt number
  45  */
  46 struct msi_map {
  47         int     index;
  48         int     virq;
  49 };
  50
  51 /*
  52  * Constant to be used for dynamic allocations when the allocation is any
  53  * free MSI index, which is either an entry in a hardware table or a
  54  * software managed index.
  55  */
  56 #define MSI_ANY_INDEX           UINT_MAX
  57
  58 unsigned int msi_domain_get_virq(struct device *dev, unsigned int domid, unsigned int index);
  59
  60 /**
  61  * msi_get_virq - Lookup the Linux interrupt number for a MSI index on the default interrupt domain
  62  * @dev:        Device for which the lookup happens
  63  * @index:      The MSI index to lookup
  64  *
  65  * Return: The Linux interrupt number on success (> 0), 0 if not found
  66  */
  67 static inline unsigned int msi_get_virq(struct device *dev, unsigned int index)
  68 {
  69         return msi_domain_get_virq(dev, MSI_DEFAULT_DOMAIN, index);
  70 }
  71
  72 #endif