1/* SPDX-License-Identifier: GPL-2.0
2 *
3 * CDX bus public interface
4 *
5 * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
6 *
7 */
8
9#ifndef _CDX_BUS_H_
10#define _CDX_BUS_H_
11
12#include <linux/device.h>
13#include <linux/list.h>
14#include <linux/mod_devicetable.h>
15#include <linux/msi.h>
16
17#define MAX_CDX_DEV_RESOURCES 4
18#define CDX_CONTROLLER_ID_SHIFT 4
19#define CDX_BUS_NUM_MASK 0xF
20
21/* Forward declaration for CDX controller */
22struct cdx_controller;
23
24enum {
25 CDX_DEV_MSI_CONF,
26 CDX_DEV_BUS_MASTER_CONF,
27 CDX_DEV_RESET_CONF,
28 CDX_DEV_MSI_ENABLE,
29};
30
31struct cdx_msi_config {
32 u64 addr;
33 u32 data;
34 u16 msi_index;
35};
36
37struct cdx_device_config {
38 u8 type;
39 union {
40 struct cdx_msi_config msi;
41 bool bus_master_enable;
42 bool msi_enable;
43 };
44};
45
46typedef int (*cdx_bus_enable_cb)(struct cdx_controller *cdx, u8 bus_num);
47
48typedef int (*cdx_bus_disable_cb)(struct cdx_controller *cdx, u8 bus_num);
49
50typedef int (*cdx_scan_cb)(struct cdx_controller *cdx);
51
52typedef int (*cdx_dev_configure_cb)(struct cdx_controller *cdx,
53 u8 bus_num, u8 dev_num,
54 struct cdx_device_config *dev_config);
55
56/**
57 * CDX_DEVICE - macro used to describe a specific CDX device
58 * @vend: the 16 bit CDX Vendor ID
59 * @dev: the 16 bit CDX Device ID
60 *
61 * This macro is used to create a struct cdx_device_id that matches a
62 * specific device. The subvendor and subdevice fields will be set to
63 * CDX_ANY_ID.
64 */
65#define CDX_DEVICE(vend, dev) \
66 .vendor = (vend), .device = (dev), \
67 .subvendor = CDX_ANY_ID, .subdevice = CDX_ANY_ID
68
69/**
70 * CDX_DEVICE_DRIVER_OVERRIDE - macro used to describe a CDX device with
71 * override_only flags.
72 * @vend: the 16 bit CDX Vendor ID
73 * @dev: the 16 bit CDX Device ID
74 * @driver_override: the 32 bit CDX Device override_only
75 *
76 * This macro is used to create a struct cdx_device_id that matches only a
77 * driver_override device. The subvendor and subdevice fields will be set to
78 * CDX_ANY_ID.
79 */
80#define CDX_DEVICE_DRIVER_OVERRIDE(vend, dev, driver_override) \
81 .vendor = (vend), .device = (dev), .subvendor = CDX_ANY_ID,\
82 .subdevice = CDX_ANY_ID, .override_only = (driver_override)
83
84/**
85 * struct cdx_ops - Callbacks supported by CDX controller.
86 * @bus_enable: enable bus on the controller
87 * @bus_disable: disable bus on the controller
88 * @scan: scan the devices on the controller
89 * @dev_configure: configuration like reset, master_enable,
90 * msi_config etc for a CDX device
91 */
92struct cdx_ops {
93 cdx_bus_enable_cb bus_enable;
94 cdx_bus_disable_cb bus_disable;
95 cdx_scan_cb scan;
96 cdx_dev_configure_cb dev_configure;
97};
98
99/**
100 * struct cdx_controller: CDX controller object
101 * @dev: Linux device associated with the CDX controller.
102 * @priv: private data
103 * @msi_domain: MSI domain
104 * @id: Controller ID
105 * @controller_registered: controller registered with bus
106 * @ops: CDX controller ops
107 */
108struct cdx_controller {
109 struct device *dev;
110 void *priv;
111 struct irq_domain *msi_domain;
112 u32 id;
113 bool controller_registered;
114 struct cdx_ops *ops;
115};
116
117/**
118 * struct cdx_device - CDX device object
119 * @dev: Linux driver model device object
120 * @cdx: CDX controller associated with the device
121 * @vendor: Vendor ID for CDX device
122 * @device: Device ID for CDX device
123 * @subsystem_vendor: Subsystem Vendor ID for CDX device
124 * @subsystem_device: Subsystem Device ID for CDX device
125 * @class: Class for the CDX device
126 * @revision: Revision of the CDX device
127 * @bus_num: Bus number for this CDX device
128 * @dev_num: Device number for this device
129 * @res: array of MMIO region entries
130 * @res_attr: resource binary attribute
131 * @debugfs_dir: debugfs directory for this device
132 * @res_count: number of valid MMIO regions
133 * @dma_mask: Default DMA mask
134 * @flags: CDX device flags
135 * @req_id: Requestor ID associated with CDX device
136 * @is_bus: Is this bus device
137 * @enabled: is this bus enabled
138 * @msi_dev_id: MSI Device ID associated with CDX device
139 * @num_msi: Number of MSI's supported by the device
140 * @driver_override: driver name to force a match; do not set directly,
141 * because core frees it; use driver_set_override() to
142 * set or clear it.
143 * @irqchip_lock: lock to synchronize irq/msi configuration
144 * @msi_write_pending: MSI write pending for this device
145 */
146struct cdx_device {
147 struct device dev;
148 struct cdx_controller *cdx;
149 u16 vendor;
150 u16 device;
151 u16 subsystem_vendor;
152 u16 subsystem_device;
153 u32 class;
154 u8 revision;
155 u8 bus_num;
156 u8 dev_num;
157 struct resource res[MAX_CDX_DEV_RESOURCES];
158 struct bin_attribute *res_attr[MAX_CDX_DEV_RESOURCES];
159 struct dentry *debugfs_dir;
160 u8 res_count;
161 u64 dma_mask;
162 u16 flags;
163 u32 req_id;
164 bool is_bus;
165 bool enabled;
166 u32 msi_dev_id;
167 u32 num_msi;
168 const char *driver_override;
169 struct mutex irqchip_lock;
170 bool msi_write_pending;
171};
172
173#define to_cdx_device(_dev) \
174 container_of(_dev, struct cdx_device, dev)
175
176#define cdx_resource_start(dev, num) ((dev)->res[(num)].start)
177#define cdx_resource_end(dev, num) ((dev)->res[(num)].end)
178#define cdx_resource_flags(dev, num) ((dev)->res[(num)].flags)
179#define cdx_resource_len(dev, num) \
180 ((cdx_resource_start((dev), (num)) == 0 && \
181 cdx_resource_end((dev), (num)) == \
182 cdx_resource_start((dev), (num))) ? 0 : \
183 (cdx_resource_end((dev), (num)) - \
184 cdx_resource_start((dev), (num)) + 1))
185/**
186 * struct cdx_driver - CDX device driver
187 * @driver: Generic device driver
188 * @match_id_table: table of supported device matching Ids
189 * @probe: Function called when a device is added
190 * @remove: Function called when a device is removed
191 * @shutdown: Function called at shutdown time to quiesce the device
192 * @reset_prepare: Function called before is reset to notify driver
193 * @reset_done: Function called after reset is complete to notify driver
194 * @driver_managed_dma: Device driver doesn't use kernel DMA API for DMA.
195 * For most device drivers, no need to care about this flag
196 * as long as all DMAs are handled through the kernel DMA API.
197 * For some special ones, for example VFIO drivers, they know
198 * how to manage the DMA themselves and set this flag so that
199 * the IOMMU layer will allow them to setup and manage their
200 * own I/O address space.
201 */
202struct cdx_driver {
203 struct device_driver driver;
204 const struct cdx_device_id *match_id_table;
205 int (*probe)(struct cdx_device *dev);
206 int (*remove)(struct cdx_device *dev);
207 void (*shutdown)(struct cdx_device *dev);
208 void (*reset_prepare)(struct cdx_device *dev);
209 void (*reset_done)(struct cdx_device *dev);
210 bool driver_managed_dma;
211};
212
213#define to_cdx_driver(_drv) \
214 container_of_const(_drv, struct cdx_driver, driver)
215
216/* Macro to avoid include chaining to get THIS_MODULE */
217#define cdx_driver_register(drv) \
218 __cdx_driver_register(drv, THIS_MODULE)
219
220/**
221 * __cdx_driver_register - registers a CDX device driver
222 * @cdx_driver: CDX driver to register
223 * @owner: module owner
224 *
225 * Return: -errno on failure, 0 on success.
226 */
227int __must_check __cdx_driver_register(struct cdx_driver *cdx_driver,
228 struct module *owner);
229
230/**
231 * cdx_driver_unregister - unregisters a device driver from the
232 * CDX bus.
233 * @cdx_driver: CDX driver to register
234 */
235void cdx_driver_unregister(struct cdx_driver *cdx_driver);
236
237extern struct bus_type cdx_bus_type;
238
239/**
240 * cdx_dev_reset - Reset CDX device
241 * @dev: device pointer
242 *
243 * Return: 0 for success, -errno on failure
244 */
245int cdx_dev_reset(struct device *dev);
246
247/**
248 * cdx_set_master - enables bus-mastering for CDX device
249 * @cdx_dev: the CDX device to enable
250 *
251 * Return: 0 for success, -errno on failure
252 */
253int cdx_set_master(struct cdx_device *cdx_dev);
254
255/**
256 * cdx_clear_master - disables bus-mastering for CDX device
257 * @cdx_dev: the CDX device to disable
258 *
259 * Return: 0 for success, -errno on failure
260 */
261int cdx_clear_master(struct cdx_device *cdx_dev);
262
263#ifdef CONFIG_GENERIC_MSI_IRQ
264/**
265 * cdx_enable_msi - Enable MSI for the CDX device.
266 * @cdx_dev: device pointer
267 *
268 * Return: 0 for success, -errno on failure
269 */
270int cdx_enable_msi(struct cdx_device *cdx_dev);
271
272/**
273 * cdx_disable_msi - Disable MSI for the CDX device.
274 * @cdx_dev: device pointer
275 */
276void cdx_disable_msi(struct cdx_device *cdx_dev);
277
278#else /* CONFIG_GENERIC_MSI_IRQ */
279
280static inline int cdx_enable_msi(struct cdx_device *cdx_dev)
281{
282 return -ENODEV;
283}
284
285static inline void cdx_disable_msi(struct cdx_device *cdx_dev)
286{
287}
288
289#endif /* CONFIG_GENERIC_MSI_IRQ */
290
291#endif /* _CDX_BUS_H_ */
292