1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * PCI Backend Common Data Structures & Function Declarations
4  *
5  *   Author: Ryan Wilson <hap9@epoch.ncsc.mil>
6  */
7 #ifndef __XEN_PCIBACK_H__
8 #define __XEN_PCIBACK_H__
9 
10 #include <linux/pci.h>
11 #include <linux/interrupt.h>
12 #include <xen/xenbus.h>
13 #include <linux/list.h>
14 #include <linux/spinlock.h>
15 #include <linux/workqueue.h>
16 #include <linux/atomic.h>
17 #include <xen/interface/io/pciif.h>
18 
19 #define DRV_NAME	"xen-pciback"
20 
21 struct pci_dev_entry {
22 	struct list_head list;
23 	struct pci_dev *dev;
24 };
25 
26 #define _PDEVF_op_active	(0)
27 #define PDEVF_op_active		(1<<(_PDEVF_op_active))
28 #define _PCIB_op_pending	(1)
29 #define PCIB_op_pending		(1<<(_PCIB_op_pending))
30 
31 struct xen_pcibk_device {
32 	void *pci_dev_data;
33 	struct mutex dev_lock;
34 	struct xenbus_device *xdev;
35 	struct xenbus_watch be_watch;
36 	u8 be_watching;
37 	int evtchn_irq;
38 	struct xen_pci_sharedinfo *sh_info;
39 	unsigned long flags;
40 	struct work_struct op_work;
41 	struct xen_pci_op op;
42 };
43 
44 struct xen_pcibk_dev_data {
45 	struct list_head config_fields;
46 	struct pci_saved_state *pci_saved_state;
47 	unsigned int permissive:1;
48 	unsigned int allow_interrupt_control:1;
49 	unsigned int warned_on_write:1;
50 	unsigned int enable_intx:1;
51 	unsigned int isr_on:1; /* Whether the IRQ handler is installed. */
52 	unsigned int ack_intr:1; /* .. and ACK-ing */
53 	unsigned long handled;
54 	unsigned int irq; /* Saved in case device transitions to MSI/MSI-X */
55 	char irq_name[]; /* xen-pcibk[000:04:00.0] */
56 };
57 
58 /* Used by XenBus and xen_pcibk_ops.c */
59 extern wait_queue_head_t xen_pcibk_aer_wait_queue;
60 /* Used by pcistub.c and conf_space_quirks.c */
61 extern struct list_head xen_pcibk_quirks;
62 
63 /* Get/Put PCI Devices that are hidden from the PCI Backend Domain */
64 struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev,
65 					    int domain, int bus,
66 					    int slot, int func);
67 struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev,
68 				    struct pci_dev *dev);
69 void pcistub_put_pci_dev(struct pci_dev *dev);
70 
71 /* Ensure a device is turned off or reset */
72 void xen_pcibk_reset_device(struct pci_dev *pdev);
73 
74 /* Access a virtual configuration space for a PCI device */
75 int xen_pcibk_config_init(void);
76 int xen_pcibk_config_init_dev(struct pci_dev *dev);
77 void xen_pcibk_config_free_dyn_fields(struct pci_dev *dev);
78 void xen_pcibk_config_reset_dev(struct pci_dev *dev);
79 void xen_pcibk_config_free_dev(struct pci_dev *dev);
80 int xen_pcibk_config_read(struct pci_dev *dev, int offset, int size,
81 			  u32 *ret_val);
82 int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size,
83 			   u32 value);
84 
85 /* Handle requests for specific devices from the frontend */
86 typedef int (*publish_pci_dev_cb) (struct xen_pcibk_device *pdev,
87 				   unsigned int domain, unsigned int bus,
88 				   unsigned int devfn, unsigned int devid);
89 typedef int (*publish_pci_root_cb) (struct xen_pcibk_device *pdev,
90 				    unsigned int domain, unsigned int bus);
91 
92 /* Backend registration for the two types of BDF representation:
93  *  vpci - BDFs start at 00
94  *  passthrough - BDFs are exactly like in the host.
95  */
96 struct xen_pcibk_backend {
97 	const char *name;
98 	int (*init)(struct xen_pcibk_device *pdev);
99 	void (*free)(struct xen_pcibk_device *pdev);
100 	int (*find)(struct pci_dev *pcidev, struct xen_pcibk_device *pdev,
101 		    unsigned int *domain, unsigned int *bus,
102 		    unsigned int *devfn);
103 	int (*publish)(struct xen_pcibk_device *pdev, publish_pci_root_cb cb);
104 	void (*release)(struct xen_pcibk_device *pdev, struct pci_dev *dev,
105                         bool lock);
106 	int (*add)(struct xen_pcibk_device *pdev, struct pci_dev *dev,
107 		   int devid, publish_pci_dev_cb publish_cb);
108 	struct pci_dev *(*get)(struct xen_pcibk_device *pdev,
109 			       unsigned int domain, unsigned int bus,
110 			       unsigned int devfn);
111 };
112 
113 extern const struct xen_pcibk_backend xen_pcibk_vpci_backend;
114 extern const struct xen_pcibk_backend xen_pcibk_passthrough_backend;
115 extern const struct xen_pcibk_backend *xen_pcibk_backend;
116 
117 static inline int xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
118 					struct pci_dev *dev,
119 					int devid,
120 					publish_pci_dev_cb publish_cb)
121 {
122 	if (xen_pcibk_backend && xen_pcibk_backend->add)
123 		return xen_pcibk_backend->add(pdev, dev, devid, publish_cb);
124 	return -1;
125 }
126 
127 static inline void xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
128 					     struct pci_dev *dev, bool lock)
129 {
130 	if (xen_pcibk_backend && xen_pcibk_backend->release)
131 		return xen_pcibk_backend->release(pdev, dev, lock);
132 }
133 
134 static inline struct pci_dev *
135 xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev, unsigned int domain,
136 		      unsigned int bus, unsigned int devfn)
137 {
138 	if (xen_pcibk_backend && xen_pcibk_backend->get)
139 		return xen_pcibk_backend->get(pdev, domain, bus, devfn);
140 	return NULL;
141 }
142 
143 /**
144 * Add for domain0 PCIE-AER handling. Get guest domain/bus/devfn in xen_pcibk
145 * before sending aer request to pcifront, so that guest could identify
146 * device, coopearte with xen_pcibk to finish aer recovery job if device driver
147 * has the capability
148 */
149 static inline int xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
150 					     struct xen_pcibk_device *pdev,
151 					     unsigned int *domain,
152 					     unsigned int *bus,
153 					     unsigned int *devfn)
154 {
155 	if (xen_pcibk_backend && xen_pcibk_backend->find)
156 		return xen_pcibk_backend->find(pcidev, pdev, domain, bus,
157 					       devfn);
158 	return -1;
159 }
160 
161 static inline int xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
162 {
163 	if (xen_pcibk_backend && xen_pcibk_backend->init)
164 		return xen_pcibk_backend->init(pdev);
165 	return -1;
166 }
167 
168 static inline int xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
169 					      publish_pci_root_cb cb)
170 {
171 	if (xen_pcibk_backend && xen_pcibk_backend->publish)
172 		return xen_pcibk_backend->publish(pdev, cb);
173 	return -1;
174 }
175 
176 static inline void xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
177 {
178 	if (xen_pcibk_backend && xen_pcibk_backend->free)
179 		return xen_pcibk_backend->free(pdev);
180 }
181 
182 /* Handles events from front-end */
183 irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id);
184 void xen_pcibk_do_op(struct work_struct *data);
185 
186 int xen_pcibk_xenbus_register(void);
187 void xen_pcibk_xenbus_unregister(void);
188 
189 void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev);
190 #endif
191 
192 /* Handles shared IRQs that can to device domain and control domain. */
193 void xen_pcibk_irq_handler(struct pci_dev *dev, int reset);
194