1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __PCI_BRIDGE_EMUL_H__
3 #define __PCI_BRIDGE_EMUL_H__
4 
5 #include <linux/kernel.h>
6 
7 /* PCI configuration space of a PCI-to-PCI bridge. */
8 struct pci_bridge_emul_conf {
9 	__le16 vendor;
10 	__le16 device;
11 	__le16 command;
12 	__le16 status;
13 	__le32 class_revision;
14 	u8 cache_line_size;
15 	u8 latency_timer;
16 	u8 header_type;
17 	u8 bist;
18 	__le32 bar[2];
19 	u8 primary_bus;
20 	u8 secondary_bus;
21 	u8 subordinate_bus;
22 	u8 secondary_latency_timer;
23 	u8 iobase;
24 	u8 iolimit;
25 	__le16 secondary_status;
26 	__le16 membase;
27 	__le16 memlimit;
28 	__le16 pref_mem_base;
29 	__le16 pref_mem_limit;
30 	__le32 prefbaseupper;
31 	__le32 preflimitupper;
32 	__le16 iobaseupper;
33 	__le16 iolimitupper;
34 	u8 capabilities_pointer;
35 	u8 reserve[3];
36 	__le32 romaddr;
37 	u8 intline;
38 	u8 intpin;
39 	__le16 bridgectrl;
40 };
41 
42 /* PCI configuration space of the PCIe capabilities */
43 struct pci_bridge_emul_pcie_conf {
44 	u8 cap_id;
45 	u8 next;
46 	__le16 cap;
47 	__le32 devcap;
48 	__le16 devctl;
49 	__le16 devsta;
50 	__le32 lnkcap;
51 	__le16 lnkctl;
52 	__le16 lnksta;
53 	__le32 slotcap;
54 	__le16 slotctl;
55 	__le16 slotsta;
56 	__le16 rootctl;
57 	__le16 rootcap;
58 	__le32 rootsta;
59 	__le32 devcap2;
60 	__le16 devctl2;
61 	__le16 devsta2;
62 	__le32 lnkcap2;
63 	__le16 lnkctl2;
64 	__le16 lnksta2;
65 	__le32 slotcap2;
66 	__le16 slotctl2;
67 	__le16 slotsta2;
68 };
69 
70 struct pci_bridge_emul;
71 
72 typedef enum { PCI_BRIDGE_EMUL_HANDLED,
73 	       PCI_BRIDGE_EMUL_NOT_HANDLED } pci_bridge_emul_read_status_t;
74 
75 struct pci_bridge_emul_ops {
76 	/*
77 	 * Called when reading from the regular PCI bridge
78 	 * configuration space. Return PCI_BRIDGE_EMUL_HANDLED when the
79 	 * operation has handled the read operation and filled in the
80 	 * *value, or PCI_BRIDGE_EMUL_NOT_HANDLED when the read should
81 	 * be emulated by the common code by reading from the
82 	 * in-memory copy of the configuration space.
83 	 */
84 	pci_bridge_emul_read_status_t (*read_base)(struct pci_bridge_emul *bridge,
85 						   int reg, u32 *value);
86 
87 	/*
88 	 * Same as ->read_base(), except it is for reading from the
89 	 * PCIe capability configuration space.
90 	 */
91 	pci_bridge_emul_read_status_t (*read_pcie)(struct pci_bridge_emul *bridge,
92 						   int reg, u32 *value);
93 
94 	/*
95 	 * Same as ->read_base(), except it is for reading from the
96 	 * PCIe extended capability configuration space.
97 	 */
98 	pci_bridge_emul_read_status_t (*read_ext)(struct pci_bridge_emul *bridge,
99 						  int reg, u32 *value);
100 
101 	/*
102 	 * Called when writing to the regular PCI bridge configuration
103 	 * space. old is the current value, new is the new value being
104 	 * written, and mask indicates which parts of the value are
105 	 * being changed.
106 	 */
107 	void (*write_base)(struct pci_bridge_emul *bridge, int reg,
108 			   u32 old, u32 new, u32 mask);
109 
110 	/*
111 	 * Same as ->write_base(), except it is for writing from the
112 	 * PCIe capability configuration space.
113 	 */
114 	void (*write_pcie)(struct pci_bridge_emul *bridge, int reg,
115 			   u32 old, u32 new, u32 mask);
116 
117 	/*
118 	 * Same as ->write_base(), except it is for writing from the
119 	 * PCIe extended capability configuration space.
120 	 */
121 	void (*write_ext)(struct pci_bridge_emul *bridge, int reg,
122 			  u32 old, u32 new, u32 mask);
123 };
124 
125 struct pci_bridge_reg_behavior;
126 
127 struct pci_bridge_emul {
128 	struct pci_bridge_emul_conf conf;
129 	struct pci_bridge_emul_pcie_conf pcie_conf;
130 	const struct pci_bridge_emul_ops *ops;
131 	struct pci_bridge_reg_behavior *pci_regs_behavior;
132 	struct pci_bridge_reg_behavior *pcie_cap_regs_behavior;
133 	void *data;
134 	bool has_pcie;
135 	u16 subsystem_vendor_id;
136 	u16 subsystem_id;
137 };
138 
139 enum {
140 	/*
141 	 * PCI bridge does not support forwarding of prefetchable memory
142 	 * requests between primary and secondary buses.
143 	 */
144 	PCI_BRIDGE_EMUL_NO_PREFMEM_FORWARD = BIT(0),
145 
146 	/*
147 	 * PCI bridge does not support forwarding of IO requests between
148 	 * primary and secondary buses.
149 	 */
150 	PCI_BRIDGE_EMUL_NO_IO_FORWARD = BIT(1),
151 };
152 
153 int pci_bridge_emul_init(struct pci_bridge_emul *bridge,
154 			 unsigned int flags);
155 void pci_bridge_emul_cleanup(struct pci_bridge_emul *bridge);
156 
157 int pci_bridge_emul_conf_read(struct pci_bridge_emul *bridge, int where,
158 			      int size, u32 *value);
159 int pci_bridge_emul_conf_write(struct pci_bridge_emul *bridge, int where,
160 			       int size, u32 value);
161 
162 #endif /* __PCI_BRIDGE_EMUL_H__ */
163