xref: /openbmc/linux/drivers/cxl/cxl.h (revision 52beb1fc)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /* Copyright(c) 2020 Intel Corporation. */
3 
4 #ifndef __CXL_H__
5 #define __CXL_H__
6 
7 #include <linux/libnvdimm.h>
8 #include <linux/bitfield.h>
9 #include <linux/bitops.h>
10 #include <linux/io.h>
11 
12 /**
13  * DOC: cxl objects
14  *
15  * The CXL core objects like ports, decoders, and regions are shared
16  * between the subsystem drivers cxl_acpi, cxl_pci, and core drivers
17  * (port-driver, region-driver, nvdimm object-drivers... etc).
18  */
19 
20 /* CXL 2.0 8.2.5 CXL.cache and CXL.mem Registers*/
21 #define CXL_CM_OFFSET 0x1000
22 #define CXL_CM_CAP_HDR_OFFSET 0x0
23 #define   CXL_CM_CAP_HDR_ID_MASK GENMASK(15, 0)
24 #define     CM_CAP_HDR_CAP_ID 1
25 #define   CXL_CM_CAP_HDR_VERSION_MASK GENMASK(19, 16)
26 #define     CM_CAP_HDR_CAP_VERSION 1
27 #define   CXL_CM_CAP_HDR_CACHE_MEM_VERSION_MASK GENMASK(23, 20)
28 #define     CM_CAP_HDR_CACHE_MEM_VERSION 1
29 #define   CXL_CM_CAP_HDR_ARRAY_SIZE_MASK GENMASK(31, 24)
30 #define CXL_CM_CAP_PTR_MASK GENMASK(31, 20)
31 
32 #define   CXL_CM_CAP_CAP_ID_HDM 0x5
33 #define   CXL_CM_CAP_CAP_HDM_VERSION 1
34 
35 /* HDM decoders CXL 2.0 8.2.5.12 CXL HDM Decoder Capability Structure */
36 #define CXL_HDM_DECODER_CAP_OFFSET 0x0
37 #define   CXL_HDM_DECODER_COUNT_MASK GENMASK(3, 0)
38 #define   CXL_HDM_DECODER_TARGET_COUNT_MASK GENMASK(7, 4)
39 #define CXL_HDM_DECODER0_BASE_LOW_OFFSET 0x10
40 #define CXL_HDM_DECODER0_BASE_HIGH_OFFSET 0x14
41 #define CXL_HDM_DECODER0_SIZE_LOW_OFFSET 0x18
42 #define CXL_HDM_DECODER0_SIZE_HIGH_OFFSET 0x1c
43 #define CXL_HDM_DECODER0_CTRL_OFFSET 0x20
44 
45 static inline int cxl_hdm_decoder_count(u32 cap_hdr)
46 {
47 	int val = FIELD_GET(CXL_HDM_DECODER_COUNT_MASK, cap_hdr);
48 
49 	return val ? val * 2 : 1;
50 }
51 
52 /* CXL 2.0 8.2.8.1 Device Capabilities Array Register */
53 #define CXLDEV_CAP_ARRAY_OFFSET 0x0
54 #define   CXLDEV_CAP_ARRAY_CAP_ID 0
55 #define   CXLDEV_CAP_ARRAY_ID_MASK GENMASK_ULL(15, 0)
56 #define   CXLDEV_CAP_ARRAY_COUNT_MASK GENMASK_ULL(47, 32)
57 /* CXL 2.0 8.2.8.2 CXL Device Capability Header Register */
58 #define CXLDEV_CAP_HDR_CAP_ID_MASK GENMASK(15, 0)
59 /* CXL 2.0 8.2.8.2.1 CXL Device Capabilities */
60 #define CXLDEV_CAP_CAP_ID_DEVICE_STATUS 0x1
61 #define CXLDEV_CAP_CAP_ID_PRIMARY_MAILBOX 0x2
62 #define CXLDEV_CAP_CAP_ID_SECONDARY_MAILBOX 0x3
63 #define CXLDEV_CAP_CAP_ID_MEMDEV 0x4000
64 
65 /* CXL 2.0 8.2.8.4 Mailbox Registers */
66 #define CXLDEV_MBOX_CAPS_OFFSET 0x00
67 #define   CXLDEV_MBOX_CAP_PAYLOAD_SIZE_MASK GENMASK(4, 0)
68 #define CXLDEV_MBOX_CTRL_OFFSET 0x04
69 #define   CXLDEV_MBOX_CTRL_DOORBELL BIT(0)
70 #define CXLDEV_MBOX_CMD_OFFSET 0x08
71 #define   CXLDEV_MBOX_CMD_COMMAND_OPCODE_MASK GENMASK_ULL(15, 0)
72 #define   CXLDEV_MBOX_CMD_PAYLOAD_LENGTH_MASK GENMASK_ULL(36, 16)
73 #define CXLDEV_MBOX_STATUS_OFFSET 0x10
74 #define   CXLDEV_MBOX_STATUS_RET_CODE_MASK GENMASK_ULL(47, 32)
75 #define CXLDEV_MBOX_BG_CMD_STATUS_OFFSET 0x18
76 #define CXLDEV_MBOX_PAYLOAD_OFFSET 0x20
77 
78 /*
79  * Using struct_group() allows for per register-block-type helper routines,
80  * without requiring block-type agnostic code to include the prefix.
81  */
82 struct cxl_regs {
83 	/*
84 	 * Common set of CXL Component register block base pointers
85 	 * @hdm_decoder: CXL 2.0 8.2.5.12 CXL HDM Decoder Capability Structure
86 	 */
87 	struct_group_tagged(cxl_component_regs, component,
88 		void __iomem *hdm_decoder;
89 	);
90 	/*
91 	 * Common set of CXL Device register block base pointers
92 	 * @status: CXL 2.0 8.2.8.3 Device Status Registers
93 	 * @mbox: CXL 2.0 8.2.8.4 Mailbox Registers
94 	 * @memdev: CXL 2.0 8.2.8.5 Memory Device Registers
95 	 */
96 	struct_group_tagged(cxl_device_regs, device_regs,
97 		void __iomem *status, *mbox, *memdev;
98 	);
99 };
100 
101 struct cxl_reg_map {
102 	bool valid;
103 	unsigned long offset;
104 	unsigned long size;
105 };
106 
107 struct cxl_component_reg_map {
108 	struct cxl_reg_map hdm_decoder;
109 };
110 
111 struct cxl_device_reg_map {
112 	struct cxl_reg_map status;
113 	struct cxl_reg_map mbox;
114 	struct cxl_reg_map memdev;
115 };
116 
117 /**
118  * struct cxl_register_map - DVSEC harvested register block mapping parameters
119  * @base: virtual base of the register-block-BAR + @block_offset
120  * @block_offset: offset to start of register block in @barno
121  * @reg_type: see enum cxl_regloc_type
122  * @barno: PCI BAR number containing the register block
123  * @component_map: cxl_reg_map for component registers
124  * @device_map: cxl_reg_maps for device registers
125  */
126 struct cxl_register_map {
127 	void __iomem *base;
128 	u64 block_offset;
129 	u8 reg_type;
130 	u8 barno;
131 	union {
132 		struct cxl_component_reg_map component_map;
133 		struct cxl_device_reg_map device_map;
134 	};
135 };
136 
137 void cxl_probe_component_regs(struct device *dev, void __iomem *base,
138 			      struct cxl_component_reg_map *map);
139 void cxl_probe_device_regs(struct device *dev, void __iomem *base,
140 			   struct cxl_device_reg_map *map);
141 int cxl_map_component_regs(struct pci_dev *pdev,
142 			   struct cxl_component_regs *regs,
143 			   struct cxl_register_map *map);
144 int cxl_map_device_regs(struct pci_dev *pdev,
145 			struct cxl_device_regs *regs,
146 			struct cxl_register_map *map);
147 
148 #define CXL_RESOURCE_NONE ((resource_size_t) -1)
149 #define CXL_TARGET_STRLEN 20
150 
151 /*
152  * cxl_decoder flags that define the type of memory / devices this
153  * decoder supports as well as configuration lock status See "CXL 2.0
154  * 8.2.5.12.7 CXL HDM Decoder 0 Control Register" for details.
155  */
156 #define CXL_DECODER_F_RAM   BIT(0)
157 #define CXL_DECODER_F_PMEM  BIT(1)
158 #define CXL_DECODER_F_TYPE2 BIT(2)
159 #define CXL_DECODER_F_TYPE3 BIT(3)
160 #define CXL_DECODER_F_LOCK  BIT(4)
161 #define CXL_DECODER_F_MASK  GENMASK(4, 0)
162 
163 enum cxl_decoder_type {
164        CXL_DECODER_ACCELERATOR = 2,
165        CXL_DECODER_EXPANDER = 3,
166 };
167 
168 /*
169  * Current specification goes up to 8, double that seems a reasonable
170  * software max for the foreseeable future
171  */
172 #define CXL_DECODER_MAX_INTERLEAVE 16
173 
174 /**
175  * struct cxl_decoder - CXL address range decode configuration
176  * @dev: this decoder's device
177  * @id: kernel device name id
178  * @range: address range considered by this decoder
179  * @interleave_ways: number of cxl_dports in this decode
180  * @interleave_granularity: data stride per dport
181  * @target_type: accelerator vs expander (type2 vs type3) selector
182  * @flags: memory type capabilities and locking
183  * @nr_targets: number of elements in @target
184  * @target: active ordered target list in current decoder configuration
185  */
186 struct cxl_decoder {
187 	struct device dev;
188 	int id;
189 	struct range range;
190 	int interleave_ways;
191 	int interleave_granularity;
192 	enum cxl_decoder_type target_type;
193 	unsigned long flags;
194 	int nr_targets;
195 	struct cxl_dport *target[];
196 };
197 
198 
199 /**
200  * enum cxl_nvdimm_brige_state - state machine for managing bus rescans
201  * @CXL_NVB_NEW: Set at bridge create and after cxl_pmem_wq is destroyed
202  * @CXL_NVB_DEAD: Set at brige unregistration to preclude async probing
203  * @CXL_NVB_ONLINE: Target state after successful ->probe()
204  * @CXL_NVB_OFFLINE: Target state after ->remove() or failed ->probe()
205  */
206 enum cxl_nvdimm_brige_state {
207 	CXL_NVB_NEW,
208 	CXL_NVB_DEAD,
209 	CXL_NVB_ONLINE,
210 	CXL_NVB_OFFLINE,
211 };
212 
213 struct cxl_nvdimm_bridge {
214 	int id;
215 	struct device dev;
216 	struct cxl_port *port;
217 	struct nvdimm_bus *nvdimm_bus;
218 	struct nvdimm_bus_descriptor nd_desc;
219 	struct work_struct state_work;
220 	enum cxl_nvdimm_brige_state state;
221 };
222 
223 struct cxl_nvdimm {
224 	struct device dev;
225 	struct cxl_memdev *cxlmd;
226 	struct nvdimm *nvdimm;
227 };
228 
229 struct cxl_walk_context {
230 	struct device *dev;
231 	struct pci_bus *root;
232 	struct cxl_port *port;
233 	int error;
234 	int count;
235 };
236 
237 /**
238  * struct cxl_port - logical collection of upstream port devices and
239  *		     downstream port devices to construct a CXL memory
240  *		     decode hierarchy.
241  * @dev: this port's device
242  * @uport: PCI or platform device implementing the upstream port capability
243  * @id: id for port device-name
244  * @dports: cxl_dport instances referenced by decoders
245  * @decoder_ida: allocator for decoder ids
246  * @component_reg_phys: component register capability base address (optional)
247  */
248 struct cxl_port {
249 	struct device dev;
250 	struct device *uport;
251 	int id;
252 	struct list_head dports;
253 	struct ida decoder_ida;
254 	resource_size_t component_reg_phys;
255 };
256 
257 /**
258  * struct cxl_dport - CXL downstream port
259  * @dport: PCI bridge or firmware device representing the downstream link
260  * @port_id: unique hardware identifier for dport in decoder target list
261  * @component_reg_phys: downstream port component registers
262  * @port: reference to cxl_port that contains this downstream port
263  * @list: node for a cxl_port's list of cxl_dport instances
264  */
265 struct cxl_dport {
266 	struct device *dport;
267 	int port_id;
268 	resource_size_t component_reg_phys;
269 	struct cxl_port *port;
270 	struct list_head list;
271 };
272 
273 struct cxl_port *to_cxl_port(struct device *dev);
274 struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport,
275 				   resource_size_t component_reg_phys,
276 				   struct cxl_port *parent_port);
277 
278 int cxl_add_dport(struct cxl_port *port, struct device *dport, int port_id,
279 		  resource_size_t component_reg_phys);
280 
281 struct cxl_decoder *to_cxl_decoder(struct device *dev);
282 bool is_root_decoder(struct device *dev);
283 struct cxl_decoder *cxl_decoder_alloc(struct cxl_port *port, int nr_targets);
284 int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map);
285 int cxl_decoder_autoremove(struct device *host, struct cxl_decoder *cxld);
286 
287 extern struct bus_type cxl_bus_type;
288 
289 struct cxl_driver {
290 	const char *name;
291 	int (*probe)(struct device *dev);
292 	void (*remove)(struct device *dev);
293 	struct device_driver drv;
294 	int id;
295 };
296 
297 static inline struct cxl_driver *to_cxl_drv(struct device_driver *drv)
298 {
299 	return container_of(drv, struct cxl_driver, drv);
300 }
301 
302 int __cxl_driver_register(struct cxl_driver *cxl_drv, struct module *owner,
303 			  const char *modname);
304 #define cxl_driver_register(x) __cxl_driver_register(x, THIS_MODULE, KBUILD_MODNAME)
305 void cxl_driver_unregister(struct cxl_driver *cxl_drv);
306 
307 #define CXL_DEVICE_NVDIMM_BRIDGE	1
308 #define CXL_DEVICE_NVDIMM		2
309 
310 #define MODULE_ALIAS_CXL(type) MODULE_ALIAS("cxl:t" __stringify(type) "*")
311 #define CXL_MODALIAS_FMT "cxl:t%d"
312 
313 struct cxl_nvdimm_bridge *to_cxl_nvdimm_bridge(struct device *dev);
314 struct cxl_nvdimm_bridge *devm_cxl_add_nvdimm_bridge(struct device *host,
315 						     struct cxl_port *port);
316 struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev);
317 bool is_cxl_nvdimm(struct device *dev);
318 bool is_cxl_nvdimm_bridge(struct device *dev);
319 int devm_cxl_add_nvdimm(struct device *host, struct cxl_memdev *cxlmd);
320 struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_nvdimm *cxl_nvd);
321 
322 /*
323  * Unit test builds overrides this to __weak, find the 'strong' version
324  * of these symbols in tools/testing/cxl/.
325  */
326 #ifndef __mock
327 #define __mock static
328 #endif
329 #endif /* __CXL_H__ */
330