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