tjh.dev
Linux kernel mirror (for testing)
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linux
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
16#define MAX_CDX_DEV_RESOURCES 4
17#define CDX_CONTROLLER_ID_SHIFT 4
18#define CDX_BUS_NUM_MASK 0xF
19
20/* Forward declaration for CDX controller */
21struct cdx_controller;
22
23enum {
24 CDX_DEV_RESET_CONF,
25};
26
27struct cdx_device_config {
28 u8 type;
29};
30
31typedef int (*cdx_scan_cb)(struct cdx_controller *cdx);
32
33typedef int (*cdx_dev_configure_cb)(struct cdx_controller *cdx,
34 u8 bus_num, u8 dev_num,
35 struct cdx_device_config *dev_config);
36
37/**
38 * CDX_DEVICE_DRIVER_OVERRIDE - macro used to describe a CDX device with
39 * override_only flags.
40 * @vend: the 16 bit CDX Vendor ID
41 * @dev: the 16 bit CDX Device ID
42 * @driver_override: the 32 bit CDX Device override_only
43 *
44 * This macro is used to create a struct cdx_device_id that matches only a
45 * driver_override device.
46 */
47#define CDX_DEVICE_DRIVER_OVERRIDE(vend, dev, driver_override) \
48 .vendor = (vend), .device = (dev), .override_only = (driver_override)
49
50/**
51 * struct cdx_ops - Callbacks supported by CDX controller.
52 * @scan: scan the devices on the controller
53 * @dev_configure: configuration like reset, master_enable,
54 * msi_config etc for a CDX device
55 */
56struct cdx_ops {
57 cdx_scan_cb scan;
58 cdx_dev_configure_cb dev_configure;
59};
60
61/**
62 * struct cdx_controller: CDX controller object
63 * @dev: Linux device associated with the CDX controller.
64 * @priv: private data
65 * @id: Controller ID
66 * @ops: CDX controller ops
67 */
68struct cdx_controller {
69 struct device *dev;
70 void *priv;
71 u32 id;
72 struct cdx_ops *ops;
73};
74
75/**
76 * struct cdx_device - CDX device object
77 * @dev: Linux driver model device object
78 * @cdx: CDX controller associated with the device
79 * @vendor: Vendor ID for CDX device
80 * @device: Device ID for CDX device
81 * @bus_num: Bus number for this CDX device
82 * @dev_num: Device number for this device
83 * @res: array of MMIO region entries
84 * @res_attr: resource binary attribute
85 * @res_count: number of valid MMIO regions
86 * @dma_mask: Default DMA mask
87 * @flags: CDX device flags
88 * @req_id: Requestor ID associated with CDX device
89 * @driver_override: driver name to force a match; do not set directly,
90 * because core frees it; use driver_set_override() to
91 * set or clear it.
92 */
93struct cdx_device {
94 struct device dev;
95 struct cdx_controller *cdx;
96 u16 vendor;
97 u16 device;
98 u8 bus_num;
99 u8 dev_num;
100 struct resource res[MAX_CDX_DEV_RESOURCES];
101 u8 res_count;
102 u64 dma_mask;
103 u16 flags;
104 u32 req_id;
105 const char *driver_override;
106};
107
108#define to_cdx_device(_dev) \
109 container_of(_dev, struct cdx_device, dev)
110
111/**
112 * struct cdx_driver - CDX device driver
113 * @driver: Generic device driver
114 * @match_id_table: table of supported device matching Ids
115 * @probe: Function called when a device is added
116 * @remove: Function called when a device is removed
117 * @shutdown: Function called at shutdown time to quiesce the device
118 * @reset_prepare: Function called before is reset to notify driver
119 * @reset_done: Function called after reset is complete to notify driver
120 * @driver_managed_dma: Device driver doesn't use kernel DMA API for DMA.
121 * For most device drivers, no need to care about this flag
122 * as long as all DMAs are handled through the kernel DMA API.
123 * For some special ones, for example VFIO drivers, they know
124 * how to manage the DMA themselves and set this flag so that
125 * the IOMMU layer will allow them to setup and manage their
126 * own I/O address space.
127 */
128struct cdx_driver {
129 struct device_driver driver;
130 const struct cdx_device_id *match_id_table;
131 int (*probe)(struct cdx_device *dev);
132 int (*remove)(struct cdx_device *dev);
133 void (*shutdown)(struct cdx_device *dev);
134 void (*reset_prepare)(struct cdx_device *dev);
135 void (*reset_done)(struct cdx_device *dev);
136 bool driver_managed_dma;
137};
138
139#define to_cdx_driver(_drv) \
140 container_of(_drv, struct cdx_driver, driver)
141
142/* Macro to avoid include chaining to get THIS_MODULE */
143#define cdx_driver_register(drv) \
144 __cdx_driver_register(drv, THIS_MODULE)
145
146/**
147 * __cdx_driver_register - registers a CDX device driver
148 * @cdx_driver: CDX driver to register
149 * @owner: module owner
150 *
151 * Return: -errno on failure, 0 on success.
152 */
153int __must_check __cdx_driver_register(struct cdx_driver *cdx_driver,
154 struct module *owner);
155
156/**
157 * cdx_driver_unregister - unregisters a device driver from the
158 * CDX bus.
159 * @cdx_driver: CDX driver to register
160 */
161void cdx_driver_unregister(struct cdx_driver *cdx_driver);
162
163extern struct bus_type cdx_bus_type;
164
165/**
166 * cdx_dev_reset - Reset CDX device
167 * @dev: device pointer
168 *
169 * Return: 0 for success, -errno on failure
170 */
171int cdx_dev_reset(struct device *dev);
172
173#endif /* _CDX_BUS_H_ */