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
11struct device;
12
13/*
14 * Per device interrupt domain related constants.
15 */
16enum 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 */
33union 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 */
46struct 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
58unsigned 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 */
67static 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