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 */ 22 struct cdx_controller; 23 24 enum { 25 CDX_DEV_MSI_CONF, 26 CDX_DEV_BUS_MASTER_CONF, 27 CDX_DEV_RESET_CONF, 28 CDX_DEV_MSI_ENABLE, 29 }; 30 31 struct cdx_msi_config { 32 u64 addr; 33 u32 data; 34 u16 msi_index; 35 }; 36 37 struct 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 46 typedef int (*cdx_bus_enable_cb)(struct cdx_controller *cdx, u8 bus_num); 47 48 typedef int (*cdx_bus_disable_cb)(struct cdx_controller *cdx, u8 bus_num); 49 50 typedef int (*cdx_scan_cb)(struct cdx_controller *cdx); 51 52 typedef 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 */ 92 struct 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 */ 108 struct 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 * @irqchip_lock: lock to synchronize irq/msi configuration 141 * @msi_write_pending: MSI write pending for this device 142 */ 143 struct cdx_device { 144 struct device dev; 145 struct cdx_controller *cdx; 146 u16 vendor; 147 u16 device; 148 u16 subsystem_vendor; 149 u16 subsystem_device; 150 u32 class; 151 u8 revision; 152 u8 bus_num; 153 u8 dev_num; 154 struct resource res[MAX_CDX_DEV_RESOURCES]; 155 struct bin_attribute *res_attr[MAX_CDX_DEV_RESOURCES]; 156 struct dentry *debugfs_dir; 157 u8 res_count; 158 u64 dma_mask; 159 u16 flags; 160 u32 req_id; 161 bool is_bus; 162 bool enabled; 163 u32 msi_dev_id; 164 u32 num_msi; 165 struct mutex irqchip_lock; 166 bool msi_write_pending; 167 }; 168 169 #define to_cdx_device(_dev) \ 170 container_of(_dev, struct cdx_device, dev) 171 172 #define cdx_resource_start(dev, num) ((dev)->res[(num)].start) 173 #define cdx_resource_end(dev, num) ((dev)->res[(num)].end) 174 #define cdx_resource_flags(dev, num) ((dev)->res[(num)].flags) 175 #define cdx_resource_len(dev, num) \ 176 ((cdx_resource_start((dev), (num)) == 0 && \ 177 cdx_resource_end((dev), (num)) == \ 178 cdx_resource_start((dev), (num))) ? 0 : \ 179 (cdx_resource_end((dev), (num)) - \ 180 cdx_resource_start((dev), (num)) + 1)) 181 /** 182 * struct cdx_driver - CDX device driver 183 * @driver: Generic device driver 184 * @match_id_table: table of supported device matching Ids 185 * @probe: Function called when a device is added 186 * @remove: Function called when a device is removed 187 * @shutdown: Function called at shutdown time to quiesce the device 188 * @reset_prepare: Function called before is reset to notify driver 189 * @reset_done: Function called after reset is complete to notify driver 190 * @driver_managed_dma: Device driver doesn't use kernel DMA API for DMA. 191 * For most device drivers, no need to care about this flag 192 * as long as all DMAs are handled through the kernel DMA API. 193 * For some special ones, for example VFIO drivers, they know 194 * how to manage the DMA themselves and set this flag so that 195 * the IOMMU layer will allow them to setup and manage their 196 * own I/O address space. 197 */ 198 struct cdx_driver { 199 struct device_driver driver; 200 const struct cdx_device_id *match_id_table; 201 int (*probe)(struct cdx_device *dev); 202 int (*remove)(struct cdx_device *dev); 203 void (*shutdown)(struct cdx_device *dev); 204 void (*reset_prepare)(struct cdx_device *dev); 205 void (*reset_done)(struct cdx_device *dev); 206 bool driver_managed_dma; 207 }; 208 209 #define to_cdx_driver(_drv) \ 210 container_of_const(_drv, struct cdx_driver, driver) 211 212 /* Macro to avoid include chaining to get THIS_MODULE */ 213 #define cdx_driver_register(drv) \ 214 __cdx_driver_register(drv, THIS_MODULE) 215 216 /** 217 * __cdx_driver_register - registers a CDX device driver 218 * @cdx_driver: CDX driver to register 219 * @owner: module owner 220 * 221 * Return: -errno on failure, 0 on success. 222 */ 223 int __must_check __cdx_driver_register(struct cdx_driver *cdx_driver, 224 struct module *owner); 225 226 /** 227 * cdx_driver_unregister - unregisters a device driver from the 228 * CDX bus. 229 * @cdx_driver: CDX driver to register 230 */ 231 void cdx_driver_unregister(struct cdx_driver *cdx_driver); 232 233 extern const struct bus_type cdx_bus_type; 234 235 /** 236 * cdx_dev_reset - Reset CDX device 237 * @dev: device pointer 238 * 239 * Return: 0 for success, -errno on failure 240 */ 241 int cdx_dev_reset(struct device *dev); 242 243 /** 244 * cdx_set_master - enables bus-mastering for CDX device 245 * @cdx_dev: the CDX device to enable 246 * 247 * Return: 0 for success, -errno on failure 248 */ 249 int cdx_set_master(struct cdx_device *cdx_dev); 250 251 /** 252 * cdx_clear_master - disables bus-mastering for CDX device 253 * @cdx_dev: the CDX device to disable 254 * 255 * Return: 0 for success, -errno on failure 256 */ 257 int cdx_clear_master(struct cdx_device *cdx_dev); 258 259 #ifdef CONFIG_GENERIC_MSI_IRQ 260 /** 261 * cdx_enable_msi - Enable MSI for the CDX device. 262 * @cdx_dev: device pointer 263 * 264 * Return: 0 for success, -errno on failure 265 */ 266 int cdx_enable_msi(struct cdx_device *cdx_dev); 267 268 /** 269 * cdx_disable_msi - Disable MSI for the CDX device. 270 * @cdx_dev: device pointer 271 */ 272 void cdx_disable_msi(struct cdx_device *cdx_dev); 273 274 #else /* CONFIG_GENERIC_MSI_IRQ */ 275 276 static inline int cdx_enable_msi(struct cdx_device *cdx_dev) 277 { 278 return -ENODEV; 279 } 280 281 static inline void cdx_disable_msi(struct cdx_device *cdx_dev) 282 { 283 } 284 285 #endif /* CONFIG_GENERIC_MSI_IRQ */ 286 287 #endif /* _CDX_BUS_H_ */ 288