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 */
msi_get_virq(struct device * dev,unsigned int index)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
73