xref: /openbmc/linux/drivers/cxl/cxl.h (revision eb4663b07e13bc138aad9e2a93ee9893c7139f51)
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/log2.h>
11 #include <linux/io.h>
12 
13 /**
14  * DOC: cxl objects
15  *
16  * The CXL core objects like ports, decoders, and regions are shared
17  * between the subsystem drivers cxl_acpi, cxl_pci, and core drivers
18  * (port-driver, region-driver, nvdimm object-drivers... etc).
19  */
20 
21 /* CXL 2.0 8.2.4 CXL Component Register Layout and Definition */
22 #define CXL_COMPONENT_REG_BLOCK_SIZE SZ_64K
23 
24 /* CXL 2.0 8.2.5 CXL.cache and CXL.mem Registers*/
25 #define CXL_CM_OFFSET 0x1000
26 #define CXL_CM_CAP_HDR_OFFSET 0x0
27 #define   CXL_CM_CAP_HDR_ID_MASK GENMASK(15, 0)
28 #define     CM_CAP_HDR_CAP_ID 1
29 #define   CXL_CM_CAP_HDR_VERSION_MASK GENMASK(19, 16)
30 #define     CM_CAP_HDR_CAP_VERSION 1
31 #define   CXL_CM_CAP_HDR_CACHE_MEM_VERSION_MASK GENMASK(23, 20)
32 #define     CM_CAP_HDR_CACHE_MEM_VERSION 1
33 #define   CXL_CM_CAP_HDR_ARRAY_SIZE_MASK GENMASK(31, 24)
34 #define CXL_CM_CAP_PTR_MASK GENMASK(31, 20)
35 
36 #define   CXL_CM_CAP_CAP_ID_RAS 0x2
37 #define   CXL_CM_CAP_CAP_ID_HDM 0x5
38 #define   CXL_CM_CAP_CAP_HDM_VERSION 1
39 
40 /* HDM decoders CXL 2.0 8.2.5.12 CXL HDM Decoder Capability Structure */
41 #define CXL_HDM_DECODER_CAP_OFFSET 0x0
42 #define   CXL_HDM_DECODER_COUNT_MASK GENMASK(3, 0)
43 #define   CXL_HDM_DECODER_TARGET_COUNT_MASK GENMASK(7, 4)
44 #define   CXL_HDM_DECODER_INTERLEAVE_11_8 BIT(8)
45 #define   CXL_HDM_DECODER_INTERLEAVE_14_12 BIT(9)
46 #define CXL_HDM_DECODER_CTRL_OFFSET 0x4
47 #define   CXL_HDM_DECODER_ENABLE BIT(1)
48 #define CXL_HDM_DECODER0_BASE_LOW_OFFSET(i) (0x20 * (i) + 0x10)
49 #define CXL_HDM_DECODER0_BASE_HIGH_OFFSET(i) (0x20 * (i) + 0x14)
50 #define CXL_HDM_DECODER0_SIZE_LOW_OFFSET(i) (0x20 * (i) + 0x18)
51 #define CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(i) (0x20 * (i) + 0x1c)
52 #define CXL_HDM_DECODER0_CTRL_OFFSET(i) (0x20 * (i) + 0x20)
53 #define   CXL_HDM_DECODER0_CTRL_IG_MASK GENMASK(3, 0)
54 #define   CXL_HDM_DECODER0_CTRL_IW_MASK GENMASK(7, 4)
55 #define   CXL_HDM_DECODER0_CTRL_LOCK BIT(8)
56 #define   CXL_HDM_DECODER0_CTRL_COMMIT BIT(9)
57 #define   CXL_HDM_DECODER0_CTRL_COMMITTED BIT(10)
58 #define   CXL_HDM_DECODER0_CTRL_COMMIT_ERROR BIT(11)
59 #define   CXL_HDM_DECODER0_CTRL_TYPE BIT(12)
60 #define CXL_HDM_DECODER0_TL_LOW(i) (0x20 * (i) + 0x24)
61 #define CXL_HDM_DECODER0_TL_HIGH(i) (0x20 * (i) + 0x28)
62 #define CXL_HDM_DECODER0_SKIP_LOW(i) CXL_HDM_DECODER0_TL_LOW(i)
63 #define CXL_HDM_DECODER0_SKIP_HIGH(i) CXL_HDM_DECODER0_TL_HIGH(i)
64 
65 /* HDM decoder control register constants CXL 3.0 8.2.5.19.7 */
66 #define CXL_DECODER_MIN_GRANULARITY 256
67 #define CXL_DECODER_MAX_ENCODED_IG 6
68 
69 static inline int cxl_hdm_decoder_count(u32 cap_hdr)
70 {
71 	int val = FIELD_GET(CXL_HDM_DECODER_COUNT_MASK, cap_hdr);
72 
73 	return val ? val * 2 : 1;
74 }
75 
76 /* Encode defined in CXL 2.0 8.2.5.12.7 HDM Decoder Control Register */
77 static inline int eig_to_granularity(u16 eig, unsigned int *granularity)
78 {
79 	if (eig > CXL_DECODER_MAX_ENCODED_IG)
80 		return -EINVAL;
81 	*granularity = CXL_DECODER_MIN_GRANULARITY << eig;
82 	return 0;
83 }
84 
85 /* Encode defined in CXL ECN "3, 6, 12 and 16-way memory Interleaving" */
86 static inline int eiw_to_ways(u8 eiw, unsigned int *ways)
87 {
88 	switch (eiw) {
89 	case 0 ... 4:
90 		*ways = 1 << eiw;
91 		break;
92 	case 8 ... 10:
93 		*ways = 3 << (eiw - 8);
94 		break;
95 	default:
96 		return -EINVAL;
97 	}
98 
99 	return 0;
100 }
101 
102 static inline int granularity_to_eig(int granularity, u16 *eig)
103 {
104 	if (granularity > SZ_16K || granularity < CXL_DECODER_MIN_GRANULARITY ||
105 	    !is_power_of_2(granularity))
106 		return -EINVAL;
107 	*eig = ilog2(granularity) - 8;
108 	return 0;
109 }
110 
111 static inline int ways_to_eiw(unsigned int ways, u8 *eiw)
112 {
113 	if (ways > 16)
114 		return -EINVAL;
115 	if (is_power_of_2(ways)) {
116 		*eiw = ilog2(ways);
117 		return 0;
118 	}
119 	if (ways % 3)
120 		return -EINVAL;
121 	ways /= 3;
122 	if (!is_power_of_2(ways))
123 		return -EINVAL;
124 	*eiw = ilog2(ways) + 8;
125 	return 0;
126 }
127 
128 /* RAS Registers CXL 2.0 8.2.5.9 CXL RAS Capability Structure */
129 #define CXL_RAS_UNCORRECTABLE_STATUS_OFFSET 0x0
130 #define   CXL_RAS_UNCORRECTABLE_STATUS_MASK (GENMASK(16, 14) | GENMASK(11, 0))
131 #define CXL_RAS_UNCORRECTABLE_MASK_OFFSET 0x4
132 #define   CXL_RAS_UNCORRECTABLE_MASK_MASK (GENMASK(16, 14) | GENMASK(11, 0))
133 #define   CXL_RAS_UNCORRECTABLE_MASK_F256B_MASK BIT(8)
134 #define CXL_RAS_UNCORRECTABLE_SEVERITY_OFFSET 0x8
135 #define   CXL_RAS_UNCORRECTABLE_SEVERITY_MASK (GENMASK(16, 14) | GENMASK(11, 0))
136 #define CXL_RAS_CORRECTABLE_STATUS_OFFSET 0xC
137 #define   CXL_RAS_CORRECTABLE_STATUS_MASK GENMASK(6, 0)
138 #define CXL_RAS_CORRECTABLE_MASK_OFFSET 0x10
139 #define   CXL_RAS_CORRECTABLE_MASK_MASK GENMASK(6, 0)
140 #define CXL_RAS_CAP_CONTROL_OFFSET 0x14
141 #define CXL_RAS_CAP_CONTROL_FE_MASK GENMASK(5, 0)
142 #define CXL_RAS_HEADER_LOG_OFFSET 0x18
143 #define CXL_RAS_CAPABILITY_LENGTH 0x58
144 #define CXL_HEADERLOG_SIZE SZ_512
145 #define CXL_HEADERLOG_SIZE_U32 SZ_512 / sizeof(u32)
146 
147 /* CXL 2.0 8.2.8.1 Device Capabilities Array Register */
148 #define CXLDEV_CAP_ARRAY_OFFSET 0x0
149 #define   CXLDEV_CAP_ARRAY_CAP_ID 0
150 #define   CXLDEV_CAP_ARRAY_ID_MASK GENMASK_ULL(15, 0)
151 #define   CXLDEV_CAP_ARRAY_COUNT_MASK GENMASK_ULL(47, 32)
152 /* CXL 2.0 8.2.8.2 CXL Device Capability Header Register */
153 #define CXLDEV_CAP_HDR_CAP_ID_MASK GENMASK(15, 0)
154 /* CXL 2.0 8.2.8.2.1 CXL Device Capabilities */
155 #define CXLDEV_CAP_CAP_ID_DEVICE_STATUS 0x1
156 #define CXLDEV_CAP_CAP_ID_PRIMARY_MAILBOX 0x2
157 #define CXLDEV_CAP_CAP_ID_SECONDARY_MAILBOX 0x3
158 #define CXLDEV_CAP_CAP_ID_MEMDEV 0x4000
159 
160 /* CXL 3.0 8.2.8.3.1 Event Status Register */
161 #define CXLDEV_DEV_EVENT_STATUS_OFFSET		0x00
162 #define CXLDEV_EVENT_STATUS_INFO		BIT(0)
163 #define CXLDEV_EVENT_STATUS_WARN		BIT(1)
164 #define CXLDEV_EVENT_STATUS_FAIL		BIT(2)
165 #define CXLDEV_EVENT_STATUS_FATAL		BIT(3)
166 
167 #define CXLDEV_EVENT_STATUS_ALL (CXLDEV_EVENT_STATUS_INFO |	\
168 				 CXLDEV_EVENT_STATUS_WARN |	\
169 				 CXLDEV_EVENT_STATUS_FAIL |	\
170 				 CXLDEV_EVENT_STATUS_FATAL)
171 
172 /* CXL rev 3.0 section 8.2.9.2.4; Table 8-52 */
173 #define CXLDEV_EVENT_INT_MODE_MASK	GENMASK(1, 0)
174 #define CXLDEV_EVENT_INT_MSGNUM_MASK	GENMASK(7, 4)
175 
176 /* CXL 2.0 8.2.8.4 Mailbox Registers */
177 #define CXLDEV_MBOX_CAPS_OFFSET 0x00
178 #define   CXLDEV_MBOX_CAP_PAYLOAD_SIZE_MASK GENMASK(4, 0)
179 #define CXLDEV_MBOX_CTRL_OFFSET 0x04
180 #define   CXLDEV_MBOX_CTRL_DOORBELL BIT(0)
181 #define CXLDEV_MBOX_CMD_OFFSET 0x08
182 #define   CXLDEV_MBOX_CMD_COMMAND_OPCODE_MASK GENMASK_ULL(15, 0)
183 #define   CXLDEV_MBOX_CMD_PAYLOAD_LENGTH_MASK GENMASK_ULL(36, 16)
184 #define CXLDEV_MBOX_STATUS_OFFSET 0x10
185 #define   CXLDEV_MBOX_STATUS_RET_CODE_MASK GENMASK_ULL(47, 32)
186 #define CXLDEV_MBOX_BG_CMD_STATUS_OFFSET 0x18
187 #define CXLDEV_MBOX_PAYLOAD_OFFSET 0x20
188 
189 /*
190  * Using struct_group() allows for per register-block-type helper routines,
191  * without requiring block-type agnostic code to include the prefix.
192  */
193 struct cxl_regs {
194 	/*
195 	 * Common set of CXL Component register block base pointers
196 	 * @hdm_decoder: CXL 2.0 8.2.5.12 CXL HDM Decoder Capability Structure
197 	 * @ras: CXL 2.0 8.2.5.9 CXL RAS Capability Structure
198 	 */
199 	struct_group_tagged(cxl_component_regs, component,
200 		void __iomem *hdm_decoder;
201 		void __iomem *ras;
202 	);
203 	/*
204 	 * Common set of CXL Device register block base pointers
205 	 * @status: CXL 2.0 8.2.8.3 Device Status Registers
206 	 * @mbox: CXL 2.0 8.2.8.4 Mailbox Registers
207 	 * @memdev: CXL 2.0 8.2.8.5 Memory Device Registers
208 	 */
209 	struct_group_tagged(cxl_device_regs, device_regs,
210 		void __iomem *status, *mbox, *memdev;
211 	);
212 };
213 
214 struct cxl_reg_map {
215 	bool valid;
216 	int id;
217 	unsigned long offset;
218 	unsigned long size;
219 };
220 
221 struct cxl_component_reg_map {
222 	struct cxl_reg_map hdm_decoder;
223 	struct cxl_reg_map ras;
224 };
225 
226 struct cxl_device_reg_map {
227 	struct cxl_reg_map status;
228 	struct cxl_reg_map mbox;
229 	struct cxl_reg_map memdev;
230 };
231 
232 /**
233  * struct cxl_register_map - DVSEC harvested register block mapping parameters
234  * @base: virtual base of the register-block-BAR + @block_offset
235  * @resource: physical resource base of the register block
236  * @max_size: maximum mapping size to perform register search
237  * @reg_type: see enum cxl_regloc_type
238  * @component_map: cxl_reg_map for component registers
239  * @device_map: cxl_reg_maps for device registers
240  */
241 struct cxl_register_map {
242 	void __iomem *base;
243 	resource_size_t resource;
244 	resource_size_t max_size;
245 	u8 reg_type;
246 	union {
247 		struct cxl_component_reg_map component_map;
248 		struct cxl_device_reg_map device_map;
249 	};
250 };
251 
252 void cxl_probe_component_regs(struct device *dev, void __iomem *base,
253 			      struct cxl_component_reg_map *map);
254 void cxl_probe_device_regs(struct device *dev, void __iomem *base,
255 			   struct cxl_device_reg_map *map);
256 int cxl_map_component_regs(struct device *dev, struct cxl_component_regs *regs,
257 			   struct cxl_register_map *map,
258 			   unsigned long map_mask);
259 int cxl_map_device_regs(struct device *dev, struct cxl_device_regs *regs,
260 			struct cxl_register_map *map);
261 
262 enum cxl_regloc_type;
263 int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type,
264 		      struct cxl_register_map *map);
265 struct cxl_dport;
266 resource_size_t cxl_rcd_component_reg_phys(struct device *dev,
267 					   struct cxl_dport *dport);
268 
269 #define CXL_RESOURCE_NONE ((resource_size_t) -1)
270 #define CXL_TARGET_STRLEN 20
271 
272 /*
273  * cxl_decoder flags that define the type of memory / devices this
274  * decoder supports as well as configuration lock status See "CXL 2.0
275  * 8.2.5.12.7 CXL HDM Decoder 0 Control Register" for details.
276  * Additionally indicate whether decoder settings were autodetected,
277  * user customized.
278  */
279 #define CXL_DECODER_F_RAM   BIT(0)
280 #define CXL_DECODER_F_PMEM  BIT(1)
281 #define CXL_DECODER_F_TYPE2 BIT(2)
282 #define CXL_DECODER_F_TYPE3 BIT(3)
283 #define CXL_DECODER_F_LOCK  BIT(4)
284 #define CXL_DECODER_F_ENABLE    BIT(5)
285 #define CXL_DECODER_F_MASK  GENMASK(5, 0)
286 
287 enum cxl_decoder_type {
288        CXL_DECODER_ACCELERATOR = 2,
289        CXL_DECODER_EXPANDER = 3,
290 };
291 
292 /*
293  * Current specification goes up to 8, double that seems a reasonable
294  * software max for the foreseeable future
295  */
296 #define CXL_DECODER_MAX_INTERLEAVE 16
297 
298 
299 /**
300  * struct cxl_decoder - Common CXL HDM Decoder Attributes
301  * @dev: this decoder's device
302  * @id: kernel device name id
303  * @hpa_range: Host physical address range mapped by this decoder
304  * @interleave_ways: number of cxl_dports in this decode
305  * @interleave_granularity: data stride per dport
306  * @target_type: accelerator vs expander (type2 vs type3) selector
307  * @region: currently assigned region for this decoder
308  * @flags: memory type capabilities and locking
309  * @commit: device/decoder-type specific callback to commit settings to hw
310  * @reset: device/decoder-type specific callback to reset hw settings
311 */
312 struct cxl_decoder {
313 	struct device dev;
314 	int id;
315 	struct range hpa_range;
316 	int interleave_ways;
317 	int interleave_granularity;
318 	enum cxl_decoder_type target_type;
319 	struct cxl_region *region;
320 	unsigned long flags;
321 	int (*commit)(struct cxl_decoder *cxld);
322 	int (*reset)(struct cxl_decoder *cxld);
323 };
324 
325 /*
326  * CXL_DECODER_DEAD prevents endpoints from being reattached to regions
327  * while cxld_unregister() is running
328  */
329 enum cxl_decoder_mode {
330 	CXL_DECODER_NONE,
331 	CXL_DECODER_RAM,
332 	CXL_DECODER_PMEM,
333 	CXL_DECODER_MIXED,
334 	CXL_DECODER_DEAD,
335 };
336 
337 static inline const char *cxl_decoder_mode_name(enum cxl_decoder_mode mode)
338 {
339 	static const char * const names[] = {
340 		[CXL_DECODER_NONE] = "none",
341 		[CXL_DECODER_RAM] = "ram",
342 		[CXL_DECODER_PMEM] = "pmem",
343 		[CXL_DECODER_MIXED] = "mixed",
344 	};
345 
346 	if (mode >= CXL_DECODER_NONE && mode <= CXL_DECODER_MIXED)
347 		return names[mode];
348 	return "mixed";
349 }
350 
351 /*
352  * Track whether this decoder is reserved for region autodiscovery, or
353  * free for userspace provisioning.
354  */
355 enum cxl_decoder_state {
356 	CXL_DECODER_STATE_MANUAL,
357 	CXL_DECODER_STATE_AUTO,
358 };
359 
360 /**
361  * struct cxl_endpoint_decoder - Endpoint  / SPA to DPA decoder
362  * @cxld: base cxl_decoder_object
363  * @dpa_res: actively claimed DPA span of this decoder
364  * @skip: offset into @dpa_res where @cxld.hpa_range maps
365  * @mode: which memory type / access-mode-partition this decoder targets
366  * @state: autodiscovery state
367  * @pos: interleave position in @cxld.region
368  */
369 struct cxl_endpoint_decoder {
370 	struct cxl_decoder cxld;
371 	struct resource *dpa_res;
372 	resource_size_t skip;
373 	enum cxl_decoder_mode mode;
374 	enum cxl_decoder_state state;
375 	int pos;
376 };
377 
378 /**
379  * struct cxl_switch_decoder - Switch specific CXL HDM Decoder
380  * @cxld: base cxl_decoder object
381  * @target_lock: coordinate coherent reads of the target list
382  * @nr_targets: number of elements in @target
383  * @target: active ordered target list in current decoder configuration
384  *
385  * The 'switch' decoder type represents the decoder instances of cxl_port's that
386  * route from the root of a CXL memory decode topology to the endpoints. They
387  * come in two flavors, root-level decoders, statically defined by platform
388  * firmware, and mid-level decoders, where interleave-granularity,
389  * interleave-width, and the target list are mutable.
390  */
391 struct cxl_switch_decoder {
392 	struct cxl_decoder cxld;
393 	seqlock_t target_lock;
394 	int nr_targets;
395 	struct cxl_dport *target[];
396 };
397 
398 struct cxl_root_decoder;
399 typedef struct cxl_dport *(*cxl_calc_hb_fn)(struct cxl_root_decoder *cxlrd,
400 					    int pos);
401 
402 /**
403  * struct cxl_root_decoder - Static platform CXL address decoder
404  * @res: host / parent resource for region allocations
405  * @region_id: region id for next region provisioning event
406  * @calc_hb: which host bridge covers the n'th position by granularity
407  * @platform_data: platform specific configuration data
408  * @range_lock: sync region autodiscovery by address range
409  * @cxlsd: base cxl switch decoder
410  */
411 struct cxl_root_decoder {
412 	struct resource *res;
413 	atomic_t region_id;
414 	cxl_calc_hb_fn calc_hb;
415 	void *platform_data;
416 	struct mutex range_lock;
417 	struct cxl_switch_decoder cxlsd;
418 };
419 
420 /*
421  * enum cxl_config_state - State machine for region configuration
422  * @CXL_CONFIG_IDLE: Any sysfs attribute can be written freely
423  * @CXL_CONFIG_INTERLEAVE_ACTIVE: region size has been set, no more
424  * changes to interleave_ways or interleave_granularity
425  * @CXL_CONFIG_ACTIVE: All targets have been added the region is now
426  * active
427  * @CXL_CONFIG_RESET_PENDING: see commit_store()
428  * @CXL_CONFIG_COMMIT: Soft-config has been committed to hardware
429  */
430 enum cxl_config_state {
431 	CXL_CONFIG_IDLE,
432 	CXL_CONFIG_INTERLEAVE_ACTIVE,
433 	CXL_CONFIG_ACTIVE,
434 	CXL_CONFIG_RESET_PENDING,
435 	CXL_CONFIG_COMMIT,
436 };
437 
438 /**
439  * struct cxl_region_params - region settings
440  * @state: allow the driver to lockdown further parameter changes
441  * @uuid: unique id for persistent regions
442  * @interleave_ways: number of endpoints in the region
443  * @interleave_granularity: capacity each endpoint contributes to a stripe
444  * @res: allocated iomem capacity for this region
445  * @targets: active ordered targets in current decoder configuration
446  * @nr_targets: number of targets
447  *
448  * State transitions are protected by the cxl_region_rwsem
449  */
450 struct cxl_region_params {
451 	enum cxl_config_state state;
452 	uuid_t uuid;
453 	int interleave_ways;
454 	int interleave_granularity;
455 	struct resource *res;
456 	struct cxl_endpoint_decoder *targets[CXL_DECODER_MAX_INTERLEAVE];
457 	int nr_targets;
458 };
459 
460 /*
461  * Flag whether this region needs to have its HPA span synchronized with
462  * CPU cache state at region activation time.
463  */
464 #define CXL_REGION_F_INCOHERENT 0
465 
466 /*
467  * Indicate whether this region has been assembled by autodetection or
468  * userspace assembly. Prevent endpoint decoders outside of automatic
469  * detection from being added to the region.
470  */
471 #define CXL_REGION_F_AUTO 1
472 
473 /**
474  * struct cxl_region - CXL region
475  * @dev: This region's device
476  * @id: This region's id. Id is globally unique across all regions
477  * @mode: Endpoint decoder allocation / access mode
478  * @type: Endpoint decoder target type
479  * @cxl_nvb: nvdimm bridge for coordinating @cxlr_pmem setup / shutdown
480  * @cxlr_pmem: (for pmem regions) cached copy of the nvdimm bridge
481  * @flags: Region state flags
482  * @params: active + config params for the region
483  */
484 struct cxl_region {
485 	struct device dev;
486 	int id;
487 	enum cxl_decoder_mode mode;
488 	enum cxl_decoder_type type;
489 	struct cxl_nvdimm_bridge *cxl_nvb;
490 	struct cxl_pmem_region *cxlr_pmem;
491 	unsigned long flags;
492 	struct cxl_region_params params;
493 };
494 
495 struct cxl_nvdimm_bridge {
496 	int id;
497 	struct device dev;
498 	struct cxl_port *port;
499 	struct nvdimm_bus *nvdimm_bus;
500 	struct nvdimm_bus_descriptor nd_desc;
501 };
502 
503 #define CXL_DEV_ID_LEN 19
504 
505 struct cxl_nvdimm {
506 	struct device dev;
507 	struct cxl_memdev *cxlmd;
508 	u8 dev_id[CXL_DEV_ID_LEN]; /* for nvdimm, string of 'serial' */
509 };
510 
511 struct cxl_pmem_region_mapping {
512 	struct cxl_memdev *cxlmd;
513 	struct cxl_nvdimm *cxl_nvd;
514 	u64 start;
515 	u64 size;
516 	int position;
517 };
518 
519 struct cxl_pmem_region {
520 	struct device dev;
521 	struct cxl_region *cxlr;
522 	struct nd_region *nd_region;
523 	struct range hpa_range;
524 	int nr_mappings;
525 	struct cxl_pmem_region_mapping mapping[];
526 };
527 
528 struct cxl_dax_region {
529 	struct device dev;
530 	struct cxl_region *cxlr;
531 	struct range hpa_range;
532 };
533 
534 /**
535  * struct cxl_port - logical collection of upstream port devices and
536  *		     downstream port devices to construct a CXL memory
537  *		     decode hierarchy.
538  * @dev: this port's device
539  * @uport: PCI or platform device implementing the upstream port capability
540  * @host_bridge: Shortcut to the platform attach point for this port
541  * @id: id for port device-name
542  * @dports: cxl_dport instances referenced by decoders
543  * @endpoints: cxl_ep instances, endpoints that are a descendant of this port
544  * @regions: cxl_region_ref instances, regions mapped by this port
545  * @parent_dport: dport that points to this port in the parent
546  * @decoder_ida: allocator for decoder ids
547  * @nr_dports: number of entries in @dports
548  * @hdm_end: track last allocated HDM decoder instance for allocation ordering
549  * @commit_end: cursor to track highest committed decoder for commit ordering
550  * @component_reg_phys: component register capability base address (optional)
551  * @dead: last ep has been removed, force port re-creation
552  * @depth: How deep this port is relative to the root. depth 0 is the root.
553  * @cdat: Cached CDAT data
554  * @cdat_available: Should a CDAT attribute be available in sysfs
555  */
556 struct cxl_port {
557 	struct device dev;
558 	struct device *uport;
559 	struct device *host_bridge;
560 	int id;
561 	struct xarray dports;
562 	struct xarray endpoints;
563 	struct xarray regions;
564 	struct cxl_dport *parent_dport;
565 	struct ida decoder_ida;
566 	int nr_dports;
567 	int hdm_end;
568 	int commit_end;
569 	resource_size_t component_reg_phys;
570 	bool dead;
571 	unsigned int depth;
572 	struct cxl_cdat {
573 		void *table;
574 		size_t length;
575 	} cdat;
576 	bool cdat_available;
577 };
578 
579 static inline struct cxl_dport *
580 cxl_find_dport_by_dev(struct cxl_port *port, const struct device *dport_dev)
581 {
582 	return xa_load(&port->dports, (unsigned long)dport_dev);
583 }
584 
585 /**
586  * struct cxl_dport - CXL downstream port
587  * @dport: PCI bridge or firmware device representing the downstream link
588  * @port_id: unique hardware identifier for dport in decoder target list
589  * @component_reg_phys: downstream port component registers
590  * @rcrb: base address for the Root Complex Register Block
591  * @rch: Indicate whether this dport was enumerated in RCH or VH mode
592  * @port: reference to cxl_port that contains this downstream port
593  */
594 struct cxl_dport {
595 	struct device *dport;
596 	int port_id;
597 	resource_size_t component_reg_phys;
598 	resource_size_t rcrb;
599 	bool rch;
600 	struct cxl_port *port;
601 };
602 
603 /**
604  * struct cxl_ep - track an endpoint's interest in a port
605  * @ep: device that hosts a generic CXL endpoint (expander or accelerator)
606  * @dport: which dport routes to this endpoint on @port
607  * @next: cxl switch port across the link attached to @dport NULL if
608  *	  attached to an endpoint
609  */
610 struct cxl_ep {
611 	struct device *ep;
612 	struct cxl_dport *dport;
613 	struct cxl_port *next;
614 };
615 
616 /**
617  * struct cxl_region_ref - track a region's interest in a port
618  * @port: point in topology to install this reference
619  * @decoder: decoder assigned for @region in @port
620  * @region: region for this reference
621  * @endpoints: cxl_ep references for region members beneath @port
622  * @nr_targets_set: track how many targets have been programmed during setup
623  * @nr_eps: number of endpoints beneath @port
624  * @nr_targets: number of distinct targets needed to reach @nr_eps
625  */
626 struct cxl_region_ref {
627 	struct cxl_port *port;
628 	struct cxl_decoder *decoder;
629 	struct cxl_region *region;
630 	struct xarray endpoints;
631 	int nr_targets_set;
632 	int nr_eps;
633 	int nr_targets;
634 };
635 
636 /*
637  * The platform firmware device hosting the root is also the top of the
638  * CXL port topology. All other CXL ports have another CXL port as their
639  * parent and their ->uport / host device is out-of-line of the port
640  * ancestry.
641  */
642 static inline bool is_cxl_root(struct cxl_port *port)
643 {
644 	return port->uport == port->dev.parent;
645 }
646 
647 bool is_cxl_port(const struct device *dev);
648 struct cxl_port *to_cxl_port(const struct device *dev);
649 struct pci_bus;
650 int devm_cxl_register_pci_bus(struct device *host, struct device *uport,
651 			      struct pci_bus *bus);
652 struct pci_bus *cxl_port_to_pci_bus(struct cxl_port *port);
653 struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport,
654 				   resource_size_t component_reg_phys,
655 				   struct cxl_dport *parent_dport);
656 struct cxl_port *find_cxl_root(struct cxl_port *port);
657 int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd);
658 void cxl_bus_rescan(void);
659 void cxl_bus_drain(void);
660 struct cxl_port *cxl_mem_find_port(struct cxl_memdev *cxlmd,
661 				   struct cxl_dport **dport);
662 bool schedule_cxl_memdev_detach(struct cxl_memdev *cxlmd);
663 
664 struct cxl_dport *devm_cxl_add_dport(struct cxl_port *port,
665 				     struct device *dport, int port_id,
666 				     resource_size_t component_reg_phys);
667 struct cxl_dport *devm_cxl_add_rch_dport(struct cxl_port *port,
668 					 struct device *dport_dev, int port_id,
669 					 resource_size_t rcrb);
670 
671 struct cxl_decoder *to_cxl_decoder(struct device *dev);
672 struct cxl_root_decoder *to_cxl_root_decoder(struct device *dev);
673 struct cxl_switch_decoder *to_cxl_switch_decoder(struct device *dev);
674 struct cxl_endpoint_decoder *to_cxl_endpoint_decoder(struct device *dev);
675 bool is_root_decoder(struct device *dev);
676 bool is_switch_decoder(struct device *dev);
677 bool is_endpoint_decoder(struct device *dev);
678 struct cxl_root_decoder *cxl_root_decoder_alloc(struct cxl_port *port,
679 						unsigned int nr_targets,
680 						cxl_calc_hb_fn calc_hb);
681 struct cxl_dport *cxl_hb_modulo(struct cxl_root_decoder *cxlrd, int pos);
682 struct cxl_switch_decoder *cxl_switch_decoder_alloc(struct cxl_port *port,
683 						    unsigned int nr_targets);
684 int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map);
685 struct cxl_endpoint_decoder *cxl_endpoint_decoder_alloc(struct cxl_port *port);
686 int cxl_decoder_add_locked(struct cxl_decoder *cxld, int *target_map);
687 int cxl_decoder_autoremove(struct device *host, struct cxl_decoder *cxld);
688 int cxl_endpoint_autoremove(struct cxl_memdev *cxlmd, struct cxl_port *endpoint);
689 
690 /**
691  * struct cxl_endpoint_dvsec_info - Cached DVSEC info
692  * @mem_enabled: cached value of mem_enabled in the DVSEC at init time
693  * @ranges: Number of active HDM ranges this device uses.
694  * @port: endpoint port associated with this info instance
695  * @dvsec_range: cached attributes of the ranges in the DVSEC, PCIE_DEVICE
696  */
697 struct cxl_endpoint_dvsec_info {
698 	bool mem_enabled;
699 	int ranges;
700 	struct cxl_port *port;
701 	struct range dvsec_range[2];
702 };
703 
704 struct cxl_hdm;
705 struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port,
706 				   struct cxl_endpoint_dvsec_info *info);
707 int devm_cxl_enable_hdm(struct cxl_port *port, struct cxl_hdm *cxlhdm);
708 int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm,
709 				struct cxl_endpoint_dvsec_info *info);
710 int devm_cxl_add_passthrough_decoder(struct cxl_port *port);
711 int cxl_dvsec_rr_decode(struct device *dev, int dvsec,
712 			struct cxl_endpoint_dvsec_info *info);
713 
714 bool is_cxl_region(struct device *dev);
715 
716 extern struct bus_type cxl_bus_type;
717 
718 struct cxl_driver {
719 	const char *name;
720 	int (*probe)(struct device *dev);
721 	void (*remove)(struct device *dev);
722 	struct device_driver drv;
723 	int id;
724 };
725 
726 static inline struct cxl_driver *to_cxl_drv(struct device_driver *drv)
727 {
728 	return container_of(drv, struct cxl_driver, drv);
729 }
730 
731 int __cxl_driver_register(struct cxl_driver *cxl_drv, struct module *owner,
732 			  const char *modname);
733 #define cxl_driver_register(x) __cxl_driver_register(x, THIS_MODULE, KBUILD_MODNAME)
734 void cxl_driver_unregister(struct cxl_driver *cxl_drv);
735 
736 #define module_cxl_driver(__cxl_driver) \
737 	module_driver(__cxl_driver, cxl_driver_register, cxl_driver_unregister)
738 
739 #define CXL_DEVICE_NVDIMM_BRIDGE	1
740 #define CXL_DEVICE_NVDIMM		2
741 #define CXL_DEVICE_PORT			3
742 #define CXL_DEVICE_ROOT			4
743 #define CXL_DEVICE_MEMORY_EXPANDER	5
744 #define CXL_DEVICE_REGION		6
745 #define CXL_DEVICE_PMEM_REGION		7
746 #define CXL_DEVICE_DAX_REGION		8
747 
748 #define MODULE_ALIAS_CXL(type) MODULE_ALIAS("cxl:t" __stringify(type) "*")
749 #define CXL_MODALIAS_FMT "cxl:t%d"
750 
751 struct cxl_nvdimm_bridge *to_cxl_nvdimm_bridge(struct device *dev);
752 struct cxl_nvdimm_bridge *devm_cxl_add_nvdimm_bridge(struct device *host,
753 						     struct cxl_port *port);
754 struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev);
755 bool is_cxl_nvdimm(struct device *dev);
756 bool is_cxl_nvdimm_bridge(struct device *dev);
757 int devm_cxl_add_nvdimm(struct cxl_memdev *cxlmd);
758 struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_memdev *cxlmd);
759 
760 #ifdef CONFIG_CXL_REGION
761 bool is_cxl_pmem_region(struct device *dev);
762 struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev);
763 int cxl_add_to_region(struct cxl_port *root,
764 		      struct cxl_endpoint_decoder *cxled);
765 struct cxl_dax_region *to_cxl_dax_region(struct device *dev);
766 #else
767 static inline bool is_cxl_pmem_region(struct device *dev)
768 {
769 	return false;
770 }
771 static inline struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev)
772 {
773 	return NULL;
774 }
775 static inline int cxl_add_to_region(struct cxl_port *root,
776 				    struct cxl_endpoint_decoder *cxled)
777 {
778 	return 0;
779 }
780 static inline struct cxl_dax_region *to_cxl_dax_region(struct device *dev)
781 {
782 	return NULL;
783 }
784 #endif
785 
786 /*
787  * Unit test builds overrides this to __weak, find the 'strong' version
788  * of these symbols in tools/testing/cxl/.
789  */
790 #ifndef __mock
791 #define __mock static
792 #endif
793 
794 #endif /* __CXL_H__ */
795