xref: /openbmc/linux/arch/arm64/kernel/pci.c (revision ab55c050)
1 /*
2  * Code borrowed from powerpc/kernel/pci-common.c
3  *
4  * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
5  * Copyright (C) 2014 ARM Ltd.
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * version 2 as published by the Free Software Foundation.
10  *
11  */
12 
13 #include <linux/acpi.h>
14 #include <linux/init.h>
15 #include <linux/io.h>
16 #include <linux/kernel.h>
17 #include <linux/mm.h>
18 #include <linux/of_pci.h>
19 #include <linux/of_platform.h>
20 #include <linux/slab.h>
21 
22 /*
23  * Called after each bus is probed, but before its children are examined
24  */
25 void pcibios_fixup_bus(struct pci_bus *bus)
26 {
27 	/* nothing to do, expected to be removed in the future */
28 }
29 
30 /*
31  * We don't have to worry about legacy ISA devices, so nothing to do here
32  */
33 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
34 				resource_size_t size, resource_size_t align)
35 {
36 	return res->start;
37 }
38 
39 /**
40  * pcibios_enable_device - Enable I/O and memory.
41  * @dev: PCI device to be enabled
42  * @mask: bitmask of BARs to enable
43  */
44 int pcibios_enable_device(struct pci_dev *dev, int mask)
45 {
46 	if (pci_has_flag(PCI_PROBE_ONLY))
47 		return 0;
48 
49 	return pci_enable_resources(dev, mask);
50 }
51 
52 /*
53  * Try to assign the IRQ number from DT when adding a new device
54  */
55 int pcibios_add_device(struct pci_dev *dev)
56 {
57 	dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
58 
59 	return 0;
60 }
61 
62 /*
63  * raw_pci_read/write - Platform-specific PCI config space access.
64  */
65 int raw_pci_read(unsigned int domain, unsigned int bus,
66 		  unsigned int devfn, int reg, int len, u32 *val)
67 {
68 	return -ENXIO;
69 }
70 
71 int raw_pci_write(unsigned int domain, unsigned int bus,
72 		unsigned int devfn, int reg, int len, u32 val)
73 {
74 	return -ENXIO;
75 }
76 
77 #ifdef CONFIG_NUMA
78 
79 int pcibus_to_node(struct pci_bus *bus)
80 {
81 	return dev_to_node(&bus->dev);
82 }
83 EXPORT_SYMBOL(pcibus_to_node);
84 
85 #endif
86 
87 #ifdef CONFIG_ACPI
88 /* Root bridge scanning */
89 struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
90 {
91 	/* TODO: Should be revisited when implementing PCI on ACPI */
92 	return NULL;
93 }
94 #endif
95