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_SECONDARY_DOMAIN,
19 MSI_MAX_DEVICE_IRQDOMAINS,
20 };
21
22 /**
23 * union msi_instance_cookie - MSI instance cookie
24 * @value: u64 value store
25 * @ptr: Pointer to usage site specific data
26 *
27 * This cookie is handed to the IMS allocation function and stored in the
28 * MSI descriptor for the interrupt chip callbacks.
29 *
30 * The content of this cookie is MSI domain implementation defined. For
31 * PCI/IMS implementations this could be a PASID or a pointer to queue
32 * memory.
33 */
34 union msi_instance_cookie {
35 u64 value;
36 void *ptr;
37 };
38
39 /**
40 * msi_map - Mapping between MSI index and Linux interrupt number
41 * @index: The MSI index, e.g. slot in the MSI-X table or
42 * a software managed index if >= 0. If negative
43 * the allocation function failed and it contains
44 * the error code.
45 * @virq: The associated Linux interrupt number
46 */
47 struct msi_map {
48 int index;
49 int virq;
50 };
51
52 /*
53 * Constant to be used for dynamic allocations when the allocation is any
54 * free MSI index, which is either an entry in a hardware table or a
55 * software managed index.
56 */
57 #define MSI_ANY_INDEX UINT_MAX
58
59 unsigned int msi_domain_get_virq(struct device *dev, unsigned int domid, unsigned int index);
60
61 /**
62 * msi_get_virq - Lookup the Linux interrupt number for a MSI index on the default interrupt domain
63 * @dev: Device for which the lookup happens
64 * @index: The MSI index to lookup
65 *
66 * Return: The Linux interrupt number on success (> 0), 0 if not found
67 */
msi_get_virq(struct device * dev,unsigned int index)68 static inline unsigned int msi_get_virq(struct device *dev, unsigned int index)
69 {
70 return msi_domain_get_virq(dev, MSI_DEFAULT_DOMAIN, index);
71 }
72
73 #endif
74