xref: /openbmc/linux/drivers/cxl/cxl.h (revision b46c5fa57cc60692412f616ac66ab624a941fdb3)
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_CAP_BG_CMD_IRQ BIT(6)
180 #define   CXLDEV_MBOX_CAP_IRQ_MSGNUM_MASK GENMASK(10, 7)
181 #define CXLDEV_MBOX_CTRL_OFFSET 0x04
182 #define   CXLDEV_MBOX_CTRL_DOORBELL BIT(0)
183 #define   CXLDEV_MBOX_CTRL_BG_CMD_IRQ BIT(2)
184 #define CXLDEV_MBOX_CMD_OFFSET 0x08
185 #define   CXLDEV_MBOX_CMD_COMMAND_OPCODE_MASK GENMASK_ULL(15, 0)
186 #define   CXLDEV_MBOX_CMD_PAYLOAD_LENGTH_MASK GENMASK_ULL(36, 16)
187 #define CXLDEV_MBOX_STATUS_OFFSET 0x10
188 #define   CXLDEV_MBOX_STATUS_BG_CMD BIT(0)
189 #define   CXLDEV_MBOX_STATUS_RET_CODE_MASK GENMASK_ULL(47, 32)
190 #define CXLDEV_MBOX_BG_CMD_STATUS_OFFSET 0x18
191 #define   CXLDEV_MBOX_BG_CMD_COMMAND_OPCODE_MASK GENMASK_ULL(15, 0)
192 #define   CXLDEV_MBOX_BG_CMD_COMMAND_PCT_MASK GENMASK_ULL(22, 16)
193 #define   CXLDEV_MBOX_BG_CMD_COMMAND_RC_MASK GENMASK_ULL(47, 32)
194 #define   CXLDEV_MBOX_BG_CMD_COMMAND_VENDOR_MASK GENMASK_ULL(63, 48)
195 #define CXLDEV_MBOX_PAYLOAD_OFFSET 0x20
196 
197 /*
198  * Using struct_group() allows for per register-block-type helper routines,
199  * without requiring block-type agnostic code to include the prefix.
200  */
201 struct cxl_regs {
202 	/*
203 	 * Common set of CXL Component register block base pointers
204 	 * @hdm_decoder: CXL 2.0 8.2.5.12 CXL HDM Decoder Capability Structure
205 	 * @ras: CXL 2.0 8.2.5.9 CXL RAS Capability Structure
206 	 */
207 	struct_group_tagged(cxl_component_regs, component,
208 		void __iomem *hdm_decoder;
209 		void __iomem *ras;
210 	);
211 	/*
212 	 * Common set of CXL Device register block base pointers
213 	 * @status: CXL 2.0 8.2.8.3 Device Status Registers
214 	 * @mbox: CXL 2.0 8.2.8.4 Mailbox Registers
215 	 * @memdev: CXL 2.0 8.2.8.5 Memory Device Registers
216 	 */
217 	struct_group_tagged(cxl_device_regs, device_regs,
218 		void __iomem *status, *mbox, *memdev;
219 	);
220 };
221 
222 struct cxl_reg_map {
223 	bool valid;
224 	int id;
225 	unsigned long offset;
226 	unsigned long size;
227 };
228 
229 struct cxl_component_reg_map {
230 	struct cxl_reg_map hdm_decoder;
231 	struct cxl_reg_map ras;
232 };
233 
234 struct cxl_device_reg_map {
235 	struct cxl_reg_map status;
236 	struct cxl_reg_map mbox;
237 	struct cxl_reg_map memdev;
238 };
239 
240 /**
241  * struct cxl_register_map - DVSEC harvested register block mapping parameters
242  * @base: virtual base of the register-block-BAR + @block_offset
243  * @resource: physical resource base of the register block
244  * @max_size: maximum mapping size to perform register search
245  * @reg_type: see enum cxl_regloc_type
246  * @component_map: cxl_reg_map for component registers
247  * @device_map: cxl_reg_maps for device registers
248  */
249 struct cxl_register_map {
250 	void __iomem *base;
251 	resource_size_t resource;
252 	resource_size_t max_size;
253 	u8 reg_type;
254 	union {
255 		struct cxl_component_reg_map component_map;
256 		struct cxl_device_reg_map device_map;
257 	};
258 };
259 
260 void cxl_probe_component_regs(struct device *dev, void __iomem *base,
261 			      struct cxl_component_reg_map *map);
262 void cxl_probe_device_regs(struct device *dev, void __iomem *base,
263 			   struct cxl_device_reg_map *map);
264 int cxl_map_component_regs(struct device *dev, struct cxl_component_regs *regs,
265 			   struct cxl_register_map *map,
266 			   unsigned long map_mask);
267 int cxl_map_device_regs(struct device *dev, struct cxl_device_regs *regs,
268 			struct cxl_register_map *map);
269 
270 enum cxl_regloc_type;
271 int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type,
272 		      struct cxl_register_map *map);
273 
274 enum cxl_rcrb {
275 	CXL_RCRB_DOWNSTREAM,
276 	CXL_RCRB_UPSTREAM,
277 };
278 resource_size_t cxl_rcrb_to_component(struct device *dev,
279 				      resource_size_t rcrb,
280 				      enum cxl_rcrb which);
281 
282 #define CXL_RESOURCE_NONE ((resource_size_t) -1)
283 #define CXL_TARGET_STRLEN 20
284 
285 /*
286  * cxl_decoder flags that define the type of memory / devices this
287  * decoder supports as well as configuration lock status See "CXL 2.0
288  * 8.2.5.12.7 CXL HDM Decoder 0 Control Register" for details.
289  * Additionally indicate whether decoder settings were autodetected,
290  * user customized.
291  */
292 #define CXL_DECODER_F_RAM   BIT(0)
293 #define CXL_DECODER_F_PMEM  BIT(1)
294 #define CXL_DECODER_F_TYPE2 BIT(2)
295 #define CXL_DECODER_F_TYPE3 BIT(3)
296 #define CXL_DECODER_F_LOCK  BIT(4)
297 #define CXL_DECODER_F_ENABLE    BIT(5)
298 #define CXL_DECODER_F_MASK  GENMASK(5, 0)
299 
300 enum cxl_decoder_type {
301        CXL_DECODER_ACCELERATOR = 2,
302        CXL_DECODER_EXPANDER = 3,
303 };
304 
305 /*
306  * Current specification goes up to 8, double that seems a reasonable
307  * software max for the foreseeable future
308  */
309 #define CXL_DECODER_MAX_INTERLEAVE 16
310 
311 
312 /**
313  * struct cxl_decoder - Common CXL HDM Decoder Attributes
314  * @dev: this decoder's device
315  * @id: kernel device name id
316  * @hpa_range: Host physical address range mapped by this decoder
317  * @interleave_ways: number of cxl_dports in this decode
318  * @interleave_granularity: data stride per dport
319  * @target_type: accelerator vs expander (type2 vs type3) selector
320  * @region: currently assigned region for this decoder
321  * @flags: memory type capabilities and locking
322  * @commit: device/decoder-type specific callback to commit settings to hw
323  * @reset: device/decoder-type specific callback to reset hw settings
324 */
325 struct cxl_decoder {
326 	struct device dev;
327 	int id;
328 	struct range hpa_range;
329 	int interleave_ways;
330 	int interleave_granularity;
331 	enum cxl_decoder_type target_type;
332 	struct cxl_region *region;
333 	unsigned long flags;
334 	int (*commit)(struct cxl_decoder *cxld);
335 	int (*reset)(struct cxl_decoder *cxld);
336 };
337 
338 /*
339  * CXL_DECODER_DEAD prevents endpoints from being reattached to regions
340  * while cxld_unregister() is running
341  */
342 enum cxl_decoder_mode {
343 	CXL_DECODER_NONE,
344 	CXL_DECODER_RAM,
345 	CXL_DECODER_PMEM,
346 	CXL_DECODER_MIXED,
347 	CXL_DECODER_DEAD,
348 };
349 
350 static inline const char *cxl_decoder_mode_name(enum cxl_decoder_mode mode)
351 {
352 	static const char * const names[] = {
353 		[CXL_DECODER_NONE] = "none",
354 		[CXL_DECODER_RAM] = "ram",
355 		[CXL_DECODER_PMEM] = "pmem",
356 		[CXL_DECODER_MIXED] = "mixed",
357 	};
358 
359 	if (mode >= CXL_DECODER_NONE && mode <= CXL_DECODER_MIXED)
360 		return names[mode];
361 	return "mixed";
362 }
363 
364 /*
365  * Track whether this decoder is reserved for region autodiscovery, or
366  * free for userspace provisioning.
367  */
368 enum cxl_decoder_state {
369 	CXL_DECODER_STATE_MANUAL,
370 	CXL_DECODER_STATE_AUTO,
371 };
372 
373 /**
374  * struct cxl_endpoint_decoder - Endpoint  / SPA to DPA decoder
375  * @cxld: base cxl_decoder_object
376  * @dpa_res: actively claimed DPA span of this decoder
377  * @skip: offset into @dpa_res where @cxld.hpa_range maps
378  * @mode: which memory type / access-mode-partition this decoder targets
379  * @state: autodiscovery state
380  * @pos: interleave position in @cxld.region
381  */
382 struct cxl_endpoint_decoder {
383 	struct cxl_decoder cxld;
384 	struct resource *dpa_res;
385 	resource_size_t skip;
386 	enum cxl_decoder_mode mode;
387 	enum cxl_decoder_state state;
388 	int pos;
389 };
390 
391 /**
392  * struct cxl_switch_decoder - Switch specific CXL HDM Decoder
393  * @cxld: base cxl_decoder object
394  * @target_lock: coordinate coherent reads of the target list
395  * @nr_targets: number of elements in @target
396  * @target: active ordered target list in current decoder configuration
397  *
398  * The 'switch' decoder type represents the decoder instances of cxl_port's that
399  * route from the root of a CXL memory decode topology to the endpoints. They
400  * come in two flavors, root-level decoders, statically defined by platform
401  * firmware, and mid-level decoders, where interleave-granularity,
402  * interleave-width, and the target list are mutable.
403  */
404 struct cxl_switch_decoder {
405 	struct cxl_decoder cxld;
406 	seqlock_t target_lock;
407 	int nr_targets;
408 	struct cxl_dport *target[];
409 };
410 
411 struct cxl_root_decoder;
412 typedef struct cxl_dport *(*cxl_calc_hb_fn)(struct cxl_root_decoder *cxlrd,
413 					    int pos);
414 
415 /**
416  * struct cxl_root_decoder - Static platform CXL address decoder
417  * @res: host / parent resource for region allocations
418  * @region_id: region id for next region provisioning event
419  * @calc_hb: which host bridge covers the n'th position by granularity
420  * @platform_data: platform specific configuration data
421  * @range_lock: sync region autodiscovery by address range
422  * @cxlsd: base cxl switch decoder
423  */
424 struct cxl_root_decoder {
425 	struct resource *res;
426 	atomic_t region_id;
427 	cxl_calc_hb_fn calc_hb;
428 	void *platform_data;
429 	struct mutex range_lock;
430 	struct cxl_switch_decoder cxlsd;
431 };
432 
433 /*
434  * enum cxl_config_state - State machine for region configuration
435  * @CXL_CONFIG_IDLE: Any sysfs attribute can be written freely
436  * @CXL_CONFIG_INTERLEAVE_ACTIVE: region size has been set, no more
437  * changes to interleave_ways or interleave_granularity
438  * @CXL_CONFIG_ACTIVE: All targets have been added the region is now
439  * active
440  * @CXL_CONFIG_RESET_PENDING: see commit_store()
441  * @CXL_CONFIG_COMMIT: Soft-config has been committed to hardware
442  */
443 enum cxl_config_state {
444 	CXL_CONFIG_IDLE,
445 	CXL_CONFIG_INTERLEAVE_ACTIVE,
446 	CXL_CONFIG_ACTIVE,
447 	CXL_CONFIG_RESET_PENDING,
448 	CXL_CONFIG_COMMIT,
449 };
450 
451 /**
452  * struct cxl_region_params - region settings
453  * @state: allow the driver to lockdown further parameter changes
454  * @uuid: unique id for persistent regions
455  * @interleave_ways: number of endpoints in the region
456  * @interleave_granularity: capacity each endpoint contributes to a stripe
457  * @res: allocated iomem capacity for this region
458  * @targets: active ordered targets in current decoder configuration
459  * @nr_targets: number of targets
460  *
461  * State transitions are protected by the cxl_region_rwsem
462  */
463 struct cxl_region_params {
464 	enum cxl_config_state state;
465 	uuid_t uuid;
466 	int interleave_ways;
467 	int interleave_granularity;
468 	struct resource *res;
469 	struct cxl_endpoint_decoder *targets[CXL_DECODER_MAX_INTERLEAVE];
470 	int nr_targets;
471 };
472 
473 /*
474  * Flag whether this region needs to have its HPA span synchronized with
475  * CPU cache state at region activation time.
476  */
477 #define CXL_REGION_F_INCOHERENT 0
478 
479 /*
480  * Indicate whether this region has been assembled by autodetection or
481  * userspace assembly. Prevent endpoint decoders outside of automatic
482  * detection from being added to the region.
483  */
484 #define CXL_REGION_F_AUTO 1
485 
486 /**
487  * struct cxl_region - CXL region
488  * @dev: This region's device
489  * @id: This region's id. Id is globally unique across all regions
490  * @mode: Endpoint decoder allocation / access mode
491  * @type: Endpoint decoder target type
492  * @cxl_nvb: nvdimm bridge for coordinating @cxlr_pmem setup / shutdown
493  * @cxlr_pmem: (for pmem regions) cached copy of the nvdimm bridge
494  * @flags: Region state flags
495  * @params: active + config params for the region
496  */
497 struct cxl_region {
498 	struct device dev;
499 	int id;
500 	enum cxl_decoder_mode mode;
501 	enum cxl_decoder_type type;
502 	struct cxl_nvdimm_bridge *cxl_nvb;
503 	struct cxl_pmem_region *cxlr_pmem;
504 	unsigned long flags;
505 	struct cxl_region_params params;
506 };
507 
508 struct cxl_nvdimm_bridge {
509 	int id;
510 	struct device dev;
511 	struct cxl_port *port;
512 	struct nvdimm_bus *nvdimm_bus;
513 	struct nvdimm_bus_descriptor nd_desc;
514 };
515 
516 #define CXL_DEV_ID_LEN 19
517 
518 struct cxl_nvdimm {
519 	struct device dev;
520 	struct cxl_memdev *cxlmd;
521 	u8 dev_id[CXL_DEV_ID_LEN]; /* for nvdimm, string of 'serial' */
522 };
523 
524 struct cxl_pmem_region_mapping {
525 	struct cxl_memdev *cxlmd;
526 	struct cxl_nvdimm *cxl_nvd;
527 	u64 start;
528 	u64 size;
529 	int position;
530 };
531 
532 struct cxl_pmem_region {
533 	struct device dev;
534 	struct cxl_region *cxlr;
535 	struct nd_region *nd_region;
536 	struct range hpa_range;
537 	int nr_mappings;
538 	struct cxl_pmem_region_mapping mapping[];
539 };
540 
541 struct cxl_dax_region {
542 	struct device dev;
543 	struct cxl_region *cxlr;
544 	struct range hpa_range;
545 };
546 
547 /**
548  * struct cxl_port - logical collection of upstream port devices and
549  *		     downstream port devices to construct a CXL memory
550  *		     decode hierarchy.
551  * @dev: this port's device
552  * @uport: PCI or platform device implementing the upstream port capability
553  * @host_bridge: Shortcut to the platform attach point for this port
554  * @id: id for port device-name
555  * @dports: cxl_dport instances referenced by decoders
556  * @endpoints: cxl_ep instances, endpoints that are a descendant of this port
557  * @regions: cxl_region_ref instances, regions mapped by this port
558  * @parent_dport: dport that points to this port in the parent
559  * @decoder_ida: allocator for decoder ids
560  * @nr_dports: number of entries in @dports
561  * @hdm_end: track last allocated HDM decoder instance for allocation ordering
562  * @commit_end: cursor to track highest committed decoder for commit ordering
563  * @component_reg_phys: component register capability base address (optional)
564  * @dead: last ep has been removed, force port re-creation
565  * @depth: How deep this port is relative to the root. depth 0 is the root.
566  * @cdat: Cached CDAT data
567  * @cdat_available: Should a CDAT attribute be available in sysfs
568  */
569 struct cxl_port {
570 	struct device dev;
571 	struct device *uport;
572 	struct device *host_bridge;
573 	int id;
574 	struct xarray dports;
575 	struct xarray endpoints;
576 	struct xarray regions;
577 	struct cxl_dport *parent_dport;
578 	struct ida decoder_ida;
579 	int nr_dports;
580 	int hdm_end;
581 	int commit_end;
582 	resource_size_t component_reg_phys;
583 	bool dead;
584 	unsigned int depth;
585 	struct cxl_cdat {
586 		void *table;
587 		size_t length;
588 	} cdat;
589 	bool cdat_available;
590 };
591 
592 static inline struct cxl_dport *
593 cxl_find_dport_by_dev(struct cxl_port *port, const struct device *dport_dev)
594 {
595 	return xa_load(&port->dports, (unsigned long)dport_dev);
596 }
597 
598 /**
599  * struct cxl_dport - CXL downstream port
600  * @dport: PCI bridge or firmware device representing the downstream link
601  * @port_id: unique hardware identifier for dport in decoder target list
602  * @component_reg_phys: downstream port component registers
603  * @rcrb: base address for the Root Complex Register Block
604  * @rch: Indicate whether this dport was enumerated in RCH or VH mode
605  * @port: reference to cxl_port that contains this downstream port
606  */
607 struct cxl_dport {
608 	struct device *dport;
609 	int port_id;
610 	resource_size_t component_reg_phys;
611 	resource_size_t rcrb;
612 	bool rch;
613 	struct cxl_port *port;
614 };
615 
616 /**
617  * struct cxl_ep - track an endpoint's interest in a port
618  * @ep: device that hosts a generic CXL endpoint (expander or accelerator)
619  * @dport: which dport routes to this endpoint on @port
620  * @next: cxl switch port across the link attached to @dport NULL if
621  *	  attached to an endpoint
622  */
623 struct cxl_ep {
624 	struct device *ep;
625 	struct cxl_dport *dport;
626 	struct cxl_port *next;
627 };
628 
629 /**
630  * struct cxl_region_ref - track a region's interest in a port
631  * @port: point in topology to install this reference
632  * @decoder: decoder assigned for @region in @port
633  * @region: region for this reference
634  * @endpoints: cxl_ep references for region members beneath @port
635  * @nr_targets_set: track how many targets have been programmed during setup
636  * @nr_eps: number of endpoints beneath @port
637  * @nr_targets: number of distinct targets needed to reach @nr_eps
638  */
639 struct cxl_region_ref {
640 	struct cxl_port *port;
641 	struct cxl_decoder *decoder;
642 	struct cxl_region *region;
643 	struct xarray endpoints;
644 	int nr_targets_set;
645 	int nr_eps;
646 	int nr_targets;
647 };
648 
649 /*
650  * The platform firmware device hosting the root is also the top of the
651  * CXL port topology. All other CXL ports have another CXL port as their
652  * parent and their ->uport / host device is out-of-line of the port
653  * ancestry.
654  */
655 static inline bool is_cxl_root(struct cxl_port *port)
656 {
657 	return port->uport == port->dev.parent;
658 }
659 
660 bool is_cxl_port(const struct device *dev);
661 struct cxl_port *to_cxl_port(const struct device *dev);
662 struct pci_bus;
663 int devm_cxl_register_pci_bus(struct device *host, struct device *uport,
664 			      struct pci_bus *bus);
665 struct pci_bus *cxl_port_to_pci_bus(struct cxl_port *port);
666 struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport,
667 				   resource_size_t component_reg_phys,
668 				   struct cxl_dport *parent_dport);
669 struct cxl_port *find_cxl_root(struct cxl_port *port);
670 int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd);
671 void cxl_bus_rescan(void);
672 void cxl_bus_drain(void);
673 struct cxl_port *cxl_mem_find_port(struct cxl_memdev *cxlmd,
674 				   struct cxl_dport **dport);
675 bool schedule_cxl_memdev_detach(struct cxl_memdev *cxlmd);
676 
677 struct cxl_dport *devm_cxl_add_dport(struct cxl_port *port,
678 				     struct device *dport, int port_id,
679 				     resource_size_t component_reg_phys);
680 struct cxl_dport *devm_cxl_add_rch_dport(struct cxl_port *port,
681 					 struct device *dport_dev, int port_id,
682 					 resource_size_t component_reg_phys,
683 					 resource_size_t rcrb);
684 
685 struct cxl_decoder *to_cxl_decoder(struct device *dev);
686 struct cxl_root_decoder *to_cxl_root_decoder(struct device *dev);
687 struct cxl_switch_decoder *to_cxl_switch_decoder(struct device *dev);
688 struct cxl_endpoint_decoder *to_cxl_endpoint_decoder(struct device *dev);
689 bool is_root_decoder(struct device *dev);
690 bool is_switch_decoder(struct device *dev);
691 bool is_endpoint_decoder(struct device *dev);
692 struct cxl_root_decoder *cxl_root_decoder_alloc(struct cxl_port *port,
693 						unsigned int nr_targets,
694 						cxl_calc_hb_fn calc_hb);
695 struct cxl_dport *cxl_hb_modulo(struct cxl_root_decoder *cxlrd, int pos);
696 struct cxl_switch_decoder *cxl_switch_decoder_alloc(struct cxl_port *port,
697 						    unsigned int nr_targets);
698 int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map);
699 struct cxl_endpoint_decoder *cxl_endpoint_decoder_alloc(struct cxl_port *port);
700 int cxl_decoder_add_locked(struct cxl_decoder *cxld, int *target_map);
701 int cxl_decoder_autoremove(struct device *host, struct cxl_decoder *cxld);
702 int cxl_endpoint_autoremove(struct cxl_memdev *cxlmd, struct cxl_port *endpoint);
703 
704 /**
705  * struct cxl_endpoint_dvsec_info - Cached DVSEC info
706  * @mem_enabled: cached value of mem_enabled in the DVSEC at init time
707  * @ranges: Number of active HDM ranges this device uses.
708  * @port: endpoint port associated with this info instance
709  * @dvsec_range: cached attributes of the ranges in the DVSEC, PCIE_DEVICE
710  */
711 struct cxl_endpoint_dvsec_info {
712 	bool mem_enabled;
713 	int ranges;
714 	struct cxl_port *port;
715 	struct range dvsec_range[2];
716 };
717 
718 struct cxl_hdm;
719 struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port,
720 				   struct cxl_endpoint_dvsec_info *info);
721 int devm_cxl_enable_hdm(struct cxl_port *port, struct cxl_hdm *cxlhdm);
722 int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm,
723 				struct cxl_endpoint_dvsec_info *info);
724 int devm_cxl_add_passthrough_decoder(struct cxl_port *port);
725 int cxl_dvsec_rr_decode(struct device *dev, int dvsec,
726 			struct cxl_endpoint_dvsec_info *info);
727 
728 bool is_cxl_region(struct device *dev);
729 
730 extern struct bus_type cxl_bus_type;
731 
732 struct cxl_driver {
733 	const char *name;
734 	int (*probe)(struct device *dev);
735 	void (*remove)(struct device *dev);
736 	struct device_driver drv;
737 	int id;
738 };
739 
740 static inline struct cxl_driver *to_cxl_drv(struct device_driver *drv)
741 {
742 	return container_of(drv, struct cxl_driver, drv);
743 }
744 
745 int __cxl_driver_register(struct cxl_driver *cxl_drv, struct module *owner,
746 			  const char *modname);
747 #define cxl_driver_register(x) __cxl_driver_register(x, THIS_MODULE, KBUILD_MODNAME)
748 void cxl_driver_unregister(struct cxl_driver *cxl_drv);
749 
750 #define module_cxl_driver(__cxl_driver) \
751 	module_driver(__cxl_driver, cxl_driver_register, cxl_driver_unregister)
752 
753 #define CXL_DEVICE_NVDIMM_BRIDGE	1
754 #define CXL_DEVICE_NVDIMM		2
755 #define CXL_DEVICE_PORT			3
756 #define CXL_DEVICE_ROOT			4
757 #define CXL_DEVICE_MEMORY_EXPANDER	5
758 #define CXL_DEVICE_REGION		6
759 #define CXL_DEVICE_PMEM_REGION		7
760 #define CXL_DEVICE_DAX_REGION		8
761 
762 #define MODULE_ALIAS_CXL(type) MODULE_ALIAS("cxl:t" __stringify(type) "*")
763 #define CXL_MODALIAS_FMT "cxl:t%d"
764 
765 struct cxl_nvdimm_bridge *to_cxl_nvdimm_bridge(struct device *dev);
766 struct cxl_nvdimm_bridge *devm_cxl_add_nvdimm_bridge(struct device *host,
767 						     struct cxl_port *port);
768 struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev);
769 bool is_cxl_nvdimm(struct device *dev);
770 bool is_cxl_nvdimm_bridge(struct device *dev);
771 int devm_cxl_add_nvdimm(struct cxl_memdev *cxlmd);
772 struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_memdev *cxlmd);
773 
774 #ifdef CONFIG_CXL_REGION
775 bool is_cxl_pmem_region(struct device *dev);
776 struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev);
777 int cxl_add_to_region(struct cxl_port *root,
778 		      struct cxl_endpoint_decoder *cxled);
779 struct cxl_dax_region *to_cxl_dax_region(struct device *dev);
780 #else
781 static inline bool is_cxl_pmem_region(struct device *dev)
782 {
783 	return false;
784 }
785 static inline struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev)
786 {
787 	return NULL;
788 }
789 static inline int cxl_add_to_region(struct cxl_port *root,
790 				    struct cxl_endpoint_decoder *cxled)
791 {
792 	return 0;
793 }
794 static inline struct cxl_dax_region *to_cxl_dax_region(struct device *dev)
795 {
796 	return NULL;
797 }
798 #endif
799 
800 /*
801  * Unit test builds overrides this to __weak, find the 'strong' version
802  * of these symbols in tools/testing/cxl/.
803  */
804 #ifndef __mock
805 #define __mock static
806 #endif
807 
808 #endif /* __CXL_H__ */
809