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 */ 21 struct cdx_controller; 22 23 enum { 24 CDX_DEV_RESET_CONF, 25 }; 26 27 struct cdx_device_config { 28 u8 type; 29 }; 30 31 typedef int (*cdx_scan_cb)(struct cdx_controller *cdx); 32 33 typedef 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 */ 56 struct 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 */ 68 struct 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 */ 93 struct 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 */ 128 struct 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 */ 153 int __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 */ 161 void cdx_driver_unregister(struct cdx_driver *cdx_driver); 162 163 extern 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 */ 171 int cdx_dev_reset(struct device *dev); 172 173 #endif /* _CDX_BUS_H_ */ 174