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/events.h>
18 #include <xen/interface/io/pciif.h>
19 
20 #define DRV_NAME	"xen-pciback"
21 
22 struct pci_dev_entry {
23 	struct list_head list;
24 	struct pci_dev *dev;
25 };
26 
27 #define _PDEVF_op_active	(0)
28 #define PDEVF_op_active		(1<<(_PDEVF_op_active))
29 #define _PCIB_op_pending	(1)
30 #define PCIB_op_pending		(1<<(_PCIB_op_pending))
31 #define _EOI_pending		(2)
32 #define EOI_pending		(1<<(_EOI_pending))
33 
34 struct xen_pcibk_device {
35 	void *pci_dev_data;
36 	struct mutex dev_lock;
37 	struct xenbus_device *xdev;
38 	struct xenbus_watch be_watch;
39 	u8 be_watching;
40 	int evtchn_irq;
41 	struct xen_pci_sharedinfo *sh_info;
42 	unsigned long flags;
43 	struct work_struct op_work;
44 	struct xen_pci_op op;
45 };
46 
47 struct xen_pcibk_dev_data {
48 	struct list_head config_fields;
49 	struct pci_saved_state *pci_saved_state;
50 	unsigned int permissive:1;
51 	unsigned int allow_interrupt_control:1;
52 	unsigned int warned_on_write:1;
53 	unsigned int enable_intx:1;
54 	unsigned int isr_on:1; /* Whether the IRQ handler is installed. */
55 	unsigned int ack_intr:1; /* .. and ACK-ing */
56 	unsigned long handled;
57 	unsigned int irq; /* Saved in case device transitions to MSI/MSI-X */
58 	char irq_name[]; /* xen-pcibk[000:04:00.0] */
59 };
60 
61 /* Used by XenBus and xen_pcibk_ops.c */
62 extern wait_queue_head_t xen_pcibk_aer_wait_queue;
63 /* Used by pcistub.c and conf_space_quirks.c */
64 extern struct list_head xen_pcibk_quirks;
65 
66 /* Get/Put PCI Devices that are hidden from the PCI Backend Domain */
67 struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev,
68 					    int domain, int bus,
69 					    int slot, int func);
70 struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev,
71 				    struct pci_dev *dev);
72 void pcistub_put_pci_dev(struct pci_dev *dev);
73 
74 static inline bool xen_pcibk_pv_support(void)
75 {
76 	return IS_ENABLED(CONFIG_XEN_PCIDEV_BACKEND);
77 }
78 
79 /* Ensure a device is turned off or reset */
80 void xen_pcibk_reset_device(struct pci_dev *pdev);
81 
82 /* Access a virtual configuration space for a PCI device */
83 int xen_pcibk_config_init(void);
84 int xen_pcibk_config_init_dev(struct pci_dev *dev);
85 void xen_pcibk_config_free_dyn_fields(struct pci_dev *dev);
86 void xen_pcibk_config_reset_dev(struct pci_dev *dev);
87 void xen_pcibk_config_free_dev(struct pci_dev *dev);
88 int xen_pcibk_config_read(struct pci_dev *dev, int offset, int size,
89 			  u32 *ret_val);
90 int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size,
91 			   u32 value);
92 
93 /* Handle requests for specific devices from the frontend */
94 typedef int (*publish_pci_dev_cb) (struct xen_pcibk_device *pdev,
95 				   unsigned int domain, unsigned int bus,
96 				   unsigned int devfn, unsigned int devid);
97 typedef int (*publish_pci_root_cb) (struct xen_pcibk_device *pdev,
98 				    unsigned int domain, unsigned int bus);
99 
100 /* Backend registration for the two types of BDF representation:
101  *  vpci - BDFs start at 00
102  *  passthrough - BDFs are exactly like in the host.
103  */
104 struct xen_pcibk_backend {
105 	const char *name;
106 	int (*init)(struct xen_pcibk_device *pdev);
107 	void (*free)(struct xen_pcibk_device *pdev);
108 	int (*find)(struct pci_dev *pcidev, struct xen_pcibk_device *pdev,
109 		    unsigned int *domain, unsigned int *bus,
110 		    unsigned int *devfn);
111 	int (*publish)(struct xen_pcibk_device *pdev, publish_pci_root_cb cb);
112 	void (*release)(struct xen_pcibk_device *pdev, struct pci_dev *dev,
113                         bool lock);
114 	int (*add)(struct xen_pcibk_device *pdev, struct pci_dev *dev,
115 		   int devid, publish_pci_dev_cb publish_cb);
116 	struct pci_dev *(*get)(struct xen_pcibk_device *pdev,
117 			       unsigned int domain, unsigned int bus,
118 			       unsigned int devfn);
119 };
120 
121 extern const struct xen_pcibk_backend xen_pcibk_vpci_backend;
122 extern const struct xen_pcibk_backend xen_pcibk_passthrough_backend;
123 extern const struct xen_pcibk_backend *xen_pcibk_backend;
124 
125 static inline int xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
126 					struct pci_dev *dev,
127 					int devid,
128 					publish_pci_dev_cb publish_cb)
129 {
130 	if (xen_pcibk_backend && xen_pcibk_backend->add)
131 		return xen_pcibk_backend->add(pdev, dev, devid, publish_cb);
132 	return -1;
133 }
134 
135 static inline void xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
136 					     struct pci_dev *dev, bool lock)
137 {
138 	if (xen_pcibk_backend && xen_pcibk_backend->release)
139 		return xen_pcibk_backend->release(pdev, dev, lock);
140 }
141 
142 static inline struct pci_dev *
143 xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev, unsigned int domain,
144 		      unsigned int bus, unsigned int devfn)
145 {
146 	if (xen_pcibk_backend && xen_pcibk_backend->get)
147 		return xen_pcibk_backend->get(pdev, domain, bus, devfn);
148 	return NULL;
149 }
150 
151 /**
152 * Add for domain0 PCIE-AER handling. Get guest domain/bus/devfn in xen_pcibk
153 * before sending aer request to pcifront, so that guest could identify
154 * device, coopearte with xen_pcibk to finish aer recovery job if device driver
155 * has the capability
156 */
157 static inline int xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
158 					     struct xen_pcibk_device *pdev,
159 					     unsigned int *domain,
160 					     unsigned int *bus,
161 					     unsigned int *devfn)
162 {
163 	if (xen_pcibk_backend && xen_pcibk_backend->find)
164 		return xen_pcibk_backend->find(pcidev, pdev, domain, bus,
165 					       devfn);
166 	return -1;
167 }
168 
169 static inline int xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
170 {
171 	if (xen_pcibk_backend && xen_pcibk_backend->init)
172 		return xen_pcibk_backend->init(pdev);
173 	return -1;
174 }
175 
176 static inline int xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
177 					      publish_pci_root_cb cb)
178 {
179 	if (xen_pcibk_backend && xen_pcibk_backend->publish)
180 		return xen_pcibk_backend->publish(pdev, cb);
181 	return -1;
182 }
183 
184 static inline void xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
185 {
186 	if (xen_pcibk_backend && xen_pcibk_backend->free)
187 		return xen_pcibk_backend->free(pdev);
188 }
189 
190 /* Handles events from front-end */
191 irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id);
192 void xen_pcibk_do_op(struct work_struct *data);
193 
194 static inline void xen_pcibk_lateeoi(struct xen_pcibk_device *pdev,
195 				     unsigned int eoi_flag)
196 {
197 	if (test_and_clear_bit(_EOI_pending, &pdev->flags))
198 		xen_irq_lateeoi(pdev->evtchn_irq, eoi_flag);
199 }
200 
201 int xen_pcibk_xenbus_register(void);
202 void xen_pcibk_xenbus_unregister(void);
203 #endif
204 
205 /* Handles shared IRQs that can to device domain and control domain. */
206 void xen_pcibk_irq_handler(struct pci_dev *dev, int reset);
207