xref: /linux/tools/power/cpupower/utils/helpers/pci.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 #if defined(__i386__) || defined(__x86_64__)
2 
3 #include <helpers/helpers.h>
4 
5 /*
6  * pci_acc_init
7  *
8  * PCI access helper function depending on libpci
9  *
10  * **pacc : if a valid pci_dev is returned
11  *         *pacc must be passed to pci_acc_cleanup to free it
12  *
13  * domain: domain
14  * bus:    bus
15  * slot:   slot
16  * func:   func
17  * vendor: vendor
18  * device: device
19  * Pass -1 for one of the six above to match any
20  *
21  * Returns :
22  * struct pci_dev which can be used with pci_{read,write}_* functions
23  *                to access the PCI config space of matching pci devices
24  */
25 struct pci_dev *pci_acc_init(struct pci_access **pacc, int domain, int bus,
26 			     int slot, int func, int vendor, int dev)
27 {
28 	struct pci_filter filter_nb_link = { domain, bus, slot, func,
29 					     vendor, dev };
30 	struct pci_dev *device;
31 
32 	*pacc = pci_alloc();
33 	if (*pacc == NULL)
34 		return NULL;
35 
36 	pci_init(*pacc);
37 	pci_scan_bus(*pacc);
38 
39 	for (device = (*pacc)->devices; device; device = device->next) {
40 		if (pci_filter_match(&filter_nb_link, device))
41 			return device;
42 	}
43 	pci_cleanup(*pacc);
44 	return NULL;
45 }
46 
47 /* Typically one wants to get a specific slot(device)/func of the root domain
48    and bus */
49 struct pci_dev *pci_slot_func_init(struct pci_access **pacc, int slot,
50 				       int func)
51 {
52 	return pci_acc_init(pacc, 0, 0, slot, func, -1, -1);
53 }
54 
55 #endif /* defined(__i386__) || defined(__x86_64__) */
56