xref: /openbmc/linux/drivers/cxl/cxl.h (revision d2f9fe695313b1e50028c1ec4cd09bea67152a60)
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_HOSTONLY 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 	struct_group_tagged(cxl_pmu_regs, pmu_regs,
222 		void __iomem *pmu;
223 	);
224 };
225 
226 struct cxl_reg_map {
227 	bool valid;
228 	int id;
229 	unsigned long offset;
230 	unsigned long size;
231 };
232 
233 struct cxl_component_reg_map {
234 	struct cxl_reg_map hdm_decoder;
235 	struct cxl_reg_map ras;
236 };
237 
238 struct cxl_device_reg_map {
239 	struct cxl_reg_map status;
240 	struct cxl_reg_map mbox;
241 	struct cxl_reg_map memdev;
242 };
243 
244 struct cxl_pmu_reg_map {
245 	struct cxl_reg_map pmu;
246 };
247 
248 /**
249  * struct cxl_register_map - DVSEC harvested register block mapping parameters
250  * @base: virtual base of the register-block-BAR + @block_offset
251  * @resource: physical resource base of the register block
252  * @max_size: maximum mapping size to perform register search
253  * @reg_type: see enum cxl_regloc_type
254  * @component_map: cxl_reg_map for component registers
255  * @device_map: cxl_reg_maps for device registers
256  * @pmu_map: cxl_reg_maps for CXL Performance Monitoring Units
257  */
258 struct cxl_register_map {
259 	void __iomem *base;
260 	resource_size_t resource;
261 	resource_size_t max_size;
262 	u8 reg_type;
263 	union {
264 		struct cxl_component_reg_map component_map;
265 		struct cxl_device_reg_map device_map;
266 		struct cxl_pmu_reg_map pmu_map;
267 	};
268 };
269 
270 void cxl_probe_component_regs(struct device *dev, void __iomem *base,
271 			      struct cxl_component_reg_map *map);
272 void cxl_probe_device_regs(struct device *dev, void __iomem *base,
273 			   struct cxl_device_reg_map *map);
274 int cxl_map_component_regs(struct device *dev, struct cxl_component_regs *regs,
275 			   const struct cxl_register_map *map,
276 			   unsigned long map_mask);
277 int cxl_map_device_regs(struct device *dev, struct cxl_device_regs *regs,
278 			const struct cxl_register_map *map);
279 int cxl_map_pmu_regs(struct pci_dev *pdev, struct cxl_pmu_regs *regs,
280 		     struct cxl_register_map *map);
281 
282 enum cxl_regloc_type;
283 int cxl_count_regblock(struct pci_dev *pdev, enum cxl_regloc_type type);
284 int cxl_find_regblock_instance(struct pci_dev *pdev, enum cxl_regloc_type type,
285 			       struct cxl_register_map *map, int index);
286 int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type,
287 		      struct cxl_register_map *map);
288 
289 enum cxl_rcrb {
290 	CXL_RCRB_DOWNSTREAM,
291 	CXL_RCRB_UPSTREAM,
292 };
293 resource_size_t cxl_rcrb_to_component(struct device *dev,
294 				      resource_size_t rcrb,
295 				      enum cxl_rcrb which);
296 
297 #define CXL_RESOURCE_NONE ((resource_size_t) -1)
298 #define CXL_TARGET_STRLEN 20
299 
300 /*
301  * cxl_decoder flags that define the type of memory / devices this
302  * decoder supports as well as configuration lock status See "CXL 2.0
303  * 8.2.5.12.7 CXL HDM Decoder 0 Control Register" for details.
304  * Additionally indicate whether decoder settings were autodetected,
305  * user customized.
306  */
307 #define CXL_DECODER_F_RAM   BIT(0)
308 #define CXL_DECODER_F_PMEM  BIT(1)
309 #define CXL_DECODER_F_TYPE2 BIT(2)
310 #define CXL_DECODER_F_TYPE3 BIT(3)
311 #define CXL_DECODER_F_LOCK  BIT(4)
312 #define CXL_DECODER_F_ENABLE    BIT(5)
313 #define CXL_DECODER_F_MASK  GENMASK(5, 0)
314 
315 enum cxl_decoder_type {
316 	CXL_DECODER_DEVMEM = 2,
317 	CXL_DECODER_HOSTONLYMEM = 3,
318 };
319 
320 /*
321  * Current specification goes up to 8, double that seems a reasonable
322  * software max for the foreseeable future
323  */
324 #define CXL_DECODER_MAX_INTERLEAVE 16
325 
326 
327 /**
328  * struct cxl_decoder - Common CXL HDM Decoder Attributes
329  * @dev: this decoder's device
330  * @id: kernel device name id
331  * @hpa_range: Host physical address range mapped by this decoder
332  * @interleave_ways: number of cxl_dports in this decode
333  * @interleave_granularity: data stride per dport
334  * @target_type: accelerator vs expander (type2 vs type3) selector
335  * @region: currently assigned region for this decoder
336  * @flags: memory type capabilities and locking
337  * @commit: device/decoder-type specific callback to commit settings to hw
338  * @reset: device/decoder-type specific callback to reset hw settings
339 */
340 struct cxl_decoder {
341 	struct device dev;
342 	int id;
343 	struct range hpa_range;
344 	int interleave_ways;
345 	int interleave_granularity;
346 	enum cxl_decoder_type target_type;
347 	struct cxl_region *region;
348 	unsigned long flags;
349 	int (*commit)(struct cxl_decoder *cxld);
350 	int (*reset)(struct cxl_decoder *cxld);
351 };
352 
353 /*
354  * CXL_DECODER_DEAD prevents endpoints from being reattached to regions
355  * while cxld_unregister() is running
356  */
357 enum cxl_decoder_mode {
358 	CXL_DECODER_NONE,
359 	CXL_DECODER_RAM,
360 	CXL_DECODER_PMEM,
361 	CXL_DECODER_MIXED,
362 	CXL_DECODER_DEAD,
363 };
364 
365 static inline const char *cxl_decoder_mode_name(enum cxl_decoder_mode mode)
366 {
367 	static const char * const names[] = {
368 		[CXL_DECODER_NONE] = "none",
369 		[CXL_DECODER_RAM] = "ram",
370 		[CXL_DECODER_PMEM] = "pmem",
371 		[CXL_DECODER_MIXED] = "mixed",
372 	};
373 
374 	if (mode >= CXL_DECODER_NONE && mode <= CXL_DECODER_MIXED)
375 		return names[mode];
376 	return "mixed";
377 }
378 
379 /*
380  * Track whether this decoder is reserved for region autodiscovery, or
381  * free for userspace provisioning.
382  */
383 enum cxl_decoder_state {
384 	CXL_DECODER_STATE_MANUAL,
385 	CXL_DECODER_STATE_AUTO,
386 };
387 
388 /**
389  * struct cxl_endpoint_decoder - Endpoint  / SPA to DPA decoder
390  * @cxld: base cxl_decoder_object
391  * @dpa_res: actively claimed DPA span of this decoder
392  * @skip: offset into @dpa_res where @cxld.hpa_range maps
393  * @mode: which memory type / access-mode-partition this decoder targets
394  * @state: autodiscovery state
395  * @pos: interleave position in @cxld.region
396  */
397 struct cxl_endpoint_decoder {
398 	struct cxl_decoder cxld;
399 	struct resource *dpa_res;
400 	resource_size_t skip;
401 	enum cxl_decoder_mode mode;
402 	enum cxl_decoder_state state;
403 	int pos;
404 };
405 
406 /**
407  * struct cxl_switch_decoder - Switch specific CXL HDM Decoder
408  * @cxld: base cxl_decoder object
409  * @target_lock: coordinate coherent reads of the target list
410  * @nr_targets: number of elements in @target
411  * @target: active ordered target list in current decoder configuration
412  *
413  * The 'switch' decoder type represents the decoder instances of cxl_port's that
414  * route from the root of a CXL memory decode topology to the endpoints. They
415  * come in two flavors, root-level decoders, statically defined by platform
416  * firmware, and mid-level decoders, where interleave-granularity,
417  * interleave-width, and the target list are mutable.
418  */
419 struct cxl_switch_decoder {
420 	struct cxl_decoder cxld;
421 	seqlock_t target_lock;
422 	int nr_targets;
423 	struct cxl_dport *target[];
424 };
425 
426 struct cxl_root_decoder;
427 typedef struct cxl_dport *(*cxl_calc_hb_fn)(struct cxl_root_decoder *cxlrd,
428 					    int pos);
429 
430 /**
431  * struct cxl_root_decoder - Static platform CXL address decoder
432  * @res: host / parent resource for region allocations
433  * @region_id: region id for next region provisioning event
434  * @calc_hb: which host bridge covers the n'th position by granularity
435  * @platform_data: platform specific configuration data
436  * @range_lock: sync region autodiscovery by address range
437  * @cxlsd: base cxl switch decoder
438  */
439 struct cxl_root_decoder {
440 	struct resource *res;
441 	atomic_t region_id;
442 	cxl_calc_hb_fn calc_hb;
443 	void *platform_data;
444 	struct mutex range_lock;
445 	struct cxl_switch_decoder cxlsd;
446 };
447 
448 /*
449  * enum cxl_config_state - State machine for region configuration
450  * @CXL_CONFIG_IDLE: Any sysfs attribute can be written freely
451  * @CXL_CONFIG_INTERLEAVE_ACTIVE: region size has been set, no more
452  * changes to interleave_ways or interleave_granularity
453  * @CXL_CONFIG_ACTIVE: All targets have been added the region is now
454  * active
455  * @CXL_CONFIG_RESET_PENDING: see commit_store()
456  * @CXL_CONFIG_COMMIT: Soft-config has been committed to hardware
457  */
458 enum cxl_config_state {
459 	CXL_CONFIG_IDLE,
460 	CXL_CONFIG_INTERLEAVE_ACTIVE,
461 	CXL_CONFIG_ACTIVE,
462 	CXL_CONFIG_RESET_PENDING,
463 	CXL_CONFIG_COMMIT,
464 };
465 
466 /**
467  * struct cxl_region_params - region settings
468  * @state: allow the driver to lockdown further parameter changes
469  * @uuid: unique id for persistent regions
470  * @interleave_ways: number of endpoints in the region
471  * @interleave_granularity: capacity each endpoint contributes to a stripe
472  * @res: allocated iomem capacity for this region
473  * @targets: active ordered targets in current decoder configuration
474  * @nr_targets: number of targets
475  *
476  * State transitions are protected by the cxl_region_rwsem
477  */
478 struct cxl_region_params {
479 	enum cxl_config_state state;
480 	uuid_t uuid;
481 	int interleave_ways;
482 	int interleave_granularity;
483 	struct resource *res;
484 	struct cxl_endpoint_decoder *targets[CXL_DECODER_MAX_INTERLEAVE];
485 	int nr_targets;
486 };
487 
488 /*
489  * Indicate whether this region has been assembled by autodetection or
490  * userspace assembly. Prevent endpoint decoders outside of automatic
491  * detection from being added to the region.
492  */
493 #define CXL_REGION_F_AUTO 0
494 
495 /*
496  * Require that a committed region successfully complete a teardown once
497  * any of its associated decoders have been torn down. This maintains
498  * the commit state for the region since there are committed decoders,
499  * but blocks cxl_region_probe().
500  */
501 #define CXL_REGION_F_NEEDS_RESET 1
502 
503 /**
504  * struct cxl_region - CXL region
505  * @dev: This region's device
506  * @id: This region's id. Id is globally unique across all regions
507  * @mode: Endpoint decoder allocation / access mode
508  * @type: Endpoint decoder target type
509  * @cxl_nvb: nvdimm bridge for coordinating @cxlr_pmem setup / shutdown
510  * @cxlr_pmem: (for pmem regions) cached copy of the nvdimm bridge
511  * @flags: Region state flags
512  * @params: active + config params for the region
513  */
514 struct cxl_region {
515 	struct device dev;
516 	int id;
517 	enum cxl_decoder_mode mode;
518 	enum cxl_decoder_type type;
519 	struct cxl_nvdimm_bridge *cxl_nvb;
520 	struct cxl_pmem_region *cxlr_pmem;
521 	unsigned long flags;
522 	struct cxl_region_params params;
523 };
524 
525 struct cxl_nvdimm_bridge {
526 	int id;
527 	struct device dev;
528 	struct cxl_port *port;
529 	struct nvdimm_bus *nvdimm_bus;
530 	struct nvdimm_bus_descriptor nd_desc;
531 };
532 
533 #define CXL_DEV_ID_LEN 19
534 
535 struct cxl_nvdimm {
536 	struct device dev;
537 	struct cxl_memdev *cxlmd;
538 	u8 dev_id[CXL_DEV_ID_LEN]; /* for nvdimm, string of 'serial' */
539 };
540 
541 struct cxl_pmem_region_mapping {
542 	struct cxl_memdev *cxlmd;
543 	struct cxl_nvdimm *cxl_nvd;
544 	u64 start;
545 	u64 size;
546 	int position;
547 };
548 
549 struct cxl_pmem_region {
550 	struct device dev;
551 	struct cxl_region *cxlr;
552 	struct nd_region *nd_region;
553 	struct range hpa_range;
554 	int nr_mappings;
555 	struct cxl_pmem_region_mapping mapping[];
556 };
557 
558 struct cxl_dax_region {
559 	struct device dev;
560 	struct cxl_region *cxlr;
561 	struct range hpa_range;
562 };
563 
564 /**
565  * struct cxl_port - logical collection of upstream port devices and
566  *		     downstream port devices to construct a CXL memory
567  *		     decode hierarchy.
568  * @dev: this port's device
569  * @uport: PCI or platform device implementing the upstream port capability
570  * @host_bridge: Shortcut to the platform attach point for this port
571  * @id: id for port device-name
572  * @dports: cxl_dport instances referenced by decoders
573  * @endpoints: cxl_ep instances, endpoints that are a descendant of this port
574  * @regions: cxl_region_ref instances, regions mapped by this port
575  * @parent_dport: dport that points to this port in the parent
576  * @decoder_ida: allocator for decoder ids
577  * @nr_dports: number of entries in @dports
578  * @hdm_end: track last allocated HDM decoder instance for allocation ordering
579  * @commit_end: cursor to track highest committed decoder for commit ordering
580  * @component_reg_phys: component register capability base address (optional)
581  * @dead: last ep has been removed, force port re-creation
582  * @depth: How deep this port is relative to the root. depth 0 is the root.
583  * @cdat: Cached CDAT data
584  * @cdat_available: Should a CDAT attribute be available in sysfs
585  */
586 struct cxl_port {
587 	struct device dev;
588 	struct device *uport;
589 	struct device *host_bridge;
590 	int id;
591 	struct xarray dports;
592 	struct xarray endpoints;
593 	struct xarray regions;
594 	struct cxl_dport *parent_dport;
595 	struct ida decoder_ida;
596 	int nr_dports;
597 	int hdm_end;
598 	int commit_end;
599 	resource_size_t component_reg_phys;
600 	bool dead;
601 	unsigned int depth;
602 	struct cxl_cdat {
603 		void *table;
604 		size_t length;
605 	} cdat;
606 	bool cdat_available;
607 };
608 
609 static inline struct cxl_dport *
610 cxl_find_dport_by_dev(struct cxl_port *port, const struct device *dport_dev)
611 {
612 	return xa_load(&port->dports, (unsigned long)dport_dev);
613 }
614 
615 /**
616  * struct cxl_dport - CXL downstream port
617  * @dport: PCI bridge or firmware device representing the downstream link
618  * @port_id: unique hardware identifier for dport in decoder target list
619  * @component_reg_phys: downstream port component registers
620  * @rcrb: base address for the Root Complex Register Block
621  * @rch: Indicate whether this dport was enumerated in RCH or VH mode
622  * @port: reference to cxl_port that contains this downstream port
623  */
624 struct cxl_dport {
625 	struct device *dport;
626 	int port_id;
627 	resource_size_t component_reg_phys;
628 	resource_size_t rcrb;
629 	bool rch;
630 	struct cxl_port *port;
631 };
632 
633 /**
634  * struct cxl_ep - track an endpoint's interest in a port
635  * @ep: device that hosts a generic CXL endpoint (expander or accelerator)
636  * @dport: which dport routes to this endpoint on @port
637  * @next: cxl switch port across the link attached to @dport NULL if
638  *	  attached to an endpoint
639  */
640 struct cxl_ep {
641 	struct device *ep;
642 	struct cxl_dport *dport;
643 	struct cxl_port *next;
644 };
645 
646 /**
647  * struct cxl_region_ref - track a region's interest in a port
648  * @port: point in topology to install this reference
649  * @decoder: decoder assigned for @region in @port
650  * @region: region for this reference
651  * @endpoints: cxl_ep references for region members beneath @port
652  * @nr_targets_set: track how many targets have been programmed during setup
653  * @nr_eps: number of endpoints beneath @port
654  * @nr_targets: number of distinct targets needed to reach @nr_eps
655  */
656 struct cxl_region_ref {
657 	struct cxl_port *port;
658 	struct cxl_decoder *decoder;
659 	struct cxl_region *region;
660 	struct xarray endpoints;
661 	int nr_targets_set;
662 	int nr_eps;
663 	int nr_targets;
664 };
665 
666 /*
667  * The platform firmware device hosting the root is also the top of the
668  * CXL port topology. All other CXL ports have another CXL port as their
669  * parent and their ->uport / host device is out-of-line of the port
670  * ancestry.
671  */
672 static inline bool is_cxl_root(struct cxl_port *port)
673 {
674 	return port->uport == port->dev.parent;
675 }
676 
677 bool is_cxl_port(const struct device *dev);
678 struct cxl_port *to_cxl_port(const struct device *dev);
679 struct pci_bus;
680 int devm_cxl_register_pci_bus(struct device *host, struct device *uport,
681 			      struct pci_bus *bus);
682 struct pci_bus *cxl_port_to_pci_bus(struct cxl_port *port);
683 struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport,
684 				   resource_size_t component_reg_phys,
685 				   struct cxl_dport *parent_dport);
686 struct cxl_port *find_cxl_root(struct cxl_port *port);
687 int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd);
688 void cxl_bus_rescan(void);
689 void cxl_bus_drain(void);
690 struct cxl_port *cxl_mem_find_port(struct cxl_memdev *cxlmd,
691 				   struct cxl_dport **dport);
692 bool schedule_cxl_memdev_detach(struct cxl_memdev *cxlmd);
693 
694 struct cxl_dport *devm_cxl_add_dport(struct cxl_port *port,
695 				     struct device *dport, int port_id,
696 				     resource_size_t component_reg_phys);
697 struct cxl_dport *devm_cxl_add_rch_dport(struct cxl_port *port,
698 					 struct device *dport_dev, int port_id,
699 					 resource_size_t component_reg_phys,
700 					 resource_size_t rcrb);
701 
702 struct cxl_decoder *to_cxl_decoder(struct device *dev);
703 struct cxl_root_decoder *to_cxl_root_decoder(struct device *dev);
704 struct cxl_switch_decoder *to_cxl_switch_decoder(struct device *dev);
705 struct cxl_endpoint_decoder *to_cxl_endpoint_decoder(struct device *dev);
706 bool is_root_decoder(struct device *dev);
707 bool is_switch_decoder(struct device *dev);
708 bool is_endpoint_decoder(struct device *dev);
709 struct cxl_root_decoder *cxl_root_decoder_alloc(struct cxl_port *port,
710 						unsigned int nr_targets,
711 						cxl_calc_hb_fn calc_hb);
712 struct cxl_dport *cxl_hb_modulo(struct cxl_root_decoder *cxlrd, int pos);
713 struct cxl_switch_decoder *cxl_switch_decoder_alloc(struct cxl_port *port,
714 						    unsigned int nr_targets);
715 int cxl_decoder_add(struct cxl_decoder *cxld, int *target_map);
716 struct cxl_endpoint_decoder *cxl_endpoint_decoder_alloc(struct cxl_port *port);
717 int cxl_decoder_add_locked(struct cxl_decoder *cxld, int *target_map);
718 int cxl_decoder_autoremove(struct device *host, struct cxl_decoder *cxld);
719 int cxl_endpoint_autoremove(struct cxl_memdev *cxlmd, struct cxl_port *endpoint);
720 
721 /**
722  * struct cxl_endpoint_dvsec_info - Cached DVSEC info
723  * @mem_enabled: cached value of mem_enabled in the DVSEC at init time
724  * @ranges: Number of active HDM ranges this device uses.
725  * @port: endpoint port associated with this info instance
726  * @dvsec_range: cached attributes of the ranges in the DVSEC, PCIE_DEVICE
727  */
728 struct cxl_endpoint_dvsec_info {
729 	bool mem_enabled;
730 	int ranges;
731 	struct cxl_port *port;
732 	struct range dvsec_range[2];
733 };
734 
735 struct cxl_hdm;
736 struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port,
737 				   struct cxl_endpoint_dvsec_info *info);
738 int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm,
739 				struct cxl_endpoint_dvsec_info *info);
740 int devm_cxl_add_passthrough_decoder(struct cxl_port *port);
741 int cxl_dvsec_rr_decode(struct device *dev, int dvsec,
742 			struct cxl_endpoint_dvsec_info *info);
743 
744 bool is_cxl_region(struct device *dev);
745 
746 extern struct bus_type cxl_bus_type;
747 
748 struct cxl_driver {
749 	const char *name;
750 	int (*probe)(struct device *dev);
751 	void (*remove)(struct device *dev);
752 	struct device_driver drv;
753 	int id;
754 };
755 
756 static inline struct cxl_driver *to_cxl_drv(struct device_driver *drv)
757 {
758 	return container_of(drv, struct cxl_driver, drv);
759 }
760 
761 int __cxl_driver_register(struct cxl_driver *cxl_drv, struct module *owner,
762 			  const char *modname);
763 #define cxl_driver_register(x) __cxl_driver_register(x, THIS_MODULE, KBUILD_MODNAME)
764 void cxl_driver_unregister(struct cxl_driver *cxl_drv);
765 
766 #define module_cxl_driver(__cxl_driver) \
767 	module_driver(__cxl_driver, cxl_driver_register, cxl_driver_unregister)
768 
769 #define CXL_DEVICE_NVDIMM_BRIDGE	1
770 #define CXL_DEVICE_NVDIMM		2
771 #define CXL_DEVICE_PORT			3
772 #define CXL_DEVICE_ROOT			4
773 #define CXL_DEVICE_MEMORY_EXPANDER	5
774 #define CXL_DEVICE_REGION		6
775 #define CXL_DEVICE_PMEM_REGION		7
776 #define CXL_DEVICE_DAX_REGION		8
777 #define CXL_DEVICE_PMU			9
778 
779 #define MODULE_ALIAS_CXL(type) MODULE_ALIAS("cxl:t" __stringify(type) "*")
780 #define CXL_MODALIAS_FMT "cxl:t%d"
781 
782 struct cxl_nvdimm_bridge *to_cxl_nvdimm_bridge(struct device *dev);
783 struct cxl_nvdimm_bridge *devm_cxl_add_nvdimm_bridge(struct device *host,
784 						     struct cxl_port *port);
785 struct cxl_nvdimm *to_cxl_nvdimm(struct device *dev);
786 bool is_cxl_nvdimm(struct device *dev);
787 bool is_cxl_nvdimm_bridge(struct device *dev);
788 int devm_cxl_add_nvdimm(struct cxl_memdev *cxlmd);
789 struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_memdev *cxlmd);
790 
791 #ifdef CONFIG_CXL_REGION
792 bool is_cxl_pmem_region(struct device *dev);
793 struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev);
794 int cxl_add_to_region(struct cxl_port *root,
795 		      struct cxl_endpoint_decoder *cxled);
796 struct cxl_dax_region *to_cxl_dax_region(struct device *dev);
797 #else
798 static inline bool is_cxl_pmem_region(struct device *dev)
799 {
800 	return false;
801 }
802 static inline struct cxl_pmem_region *to_cxl_pmem_region(struct device *dev)
803 {
804 	return NULL;
805 }
806 static inline int cxl_add_to_region(struct cxl_port *root,
807 				    struct cxl_endpoint_decoder *cxled)
808 {
809 	return 0;
810 }
811 static inline struct cxl_dax_region *to_cxl_dax_region(struct device *dev)
812 {
813 	return NULL;
814 }
815 #endif
816 
817 /*
818  * Unit test builds overrides this to __weak, find the 'strong' version
819  * of these symbols in tools/testing/cxl/.
820  */
821 #ifndef __mock
822 #define __mock static
823 #endif
824 
825 #endif /* __CXL_H__ */
826