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
22struct 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
34struct 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
47struct 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 */
62extern wait_queue_head_t xen_pcibk_aer_wait_queue;
63/* Used by pcistub.c and conf_space_quirks.c */
64extern struct list_head xen_pcibk_quirks;
65
66/* Get/Put PCI Devices that are hidden from the PCI Backend Domain */
67struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev,
68					    int domain, int bus,
69					    int slot, int func);
70struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev,
71				    struct pci_dev *dev);
72void pcistub_put_pci_dev(struct pci_dev *dev);
73
74static 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 */
80void xen_pcibk_reset_device(struct pci_dev *pdev);
81
82/* Access a virtual configuration space for a PCI device */
83int xen_pcibk_config_init(void);
84int xen_pcibk_config_init_dev(struct pci_dev *dev);
85void xen_pcibk_config_free_dyn_fields(struct pci_dev *dev);
86void xen_pcibk_config_reset_dev(struct pci_dev *dev);
87void xen_pcibk_config_free_dev(struct pci_dev *dev);
88int xen_pcibk_config_read(struct pci_dev *dev, int offset, int size,
89			  u32 *ret_val);
90int 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 */
94typedef int (*publish_pci_dev_cb) (struct xen_pcibk_device *pdev,
95				   unsigned int domain, unsigned int bus,
96				   unsigned int devfn, unsigned int devid);
97typedef 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 */
104struct 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
121extern const struct xen_pcibk_backend xen_pcibk_vpci_backend;
122extern const struct xen_pcibk_backend xen_pcibk_passthrough_backend;
123extern const struct xen_pcibk_backend *xen_pcibk_backend;
124
125static 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
135static 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
142static inline struct pci_dev *
143xen_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*/
157static 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
169static 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
176static 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
184static 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 */
191irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id);
192void xen_pcibk_do_op(struct work_struct *data);
193
194static 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
201int xen_pcibk_xenbus_register(void);
202void xen_pcibk_xenbus_unregister(void);
203#endif
204