xref: /openbmc/linux/drivers/cxl/pci.c (revision 1edd0337)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright(c) 2020 Intel Corporation. All rights reserved. */
3 #include <linux/io-64-nonatomic-lo-hi.h>
4 #include <linux/moduleparam.h>
5 #include <linux/module.h>
6 #include <linux/delay.h>
7 #include <linux/sizes.h>
8 #include <linux/mutex.h>
9 #include <linux/list.h>
10 #include <linux/pci.h>
11 #include <linux/pci-doe.h>
12 #include <linux/aer.h>
13 #include <linux/io.h>
14 #include "cxlmem.h"
15 #include "cxlpci.h"
16 #include "cxl.h"
17 
18 /**
19  * DOC: cxl pci
20  *
21  * This implements the PCI exclusive functionality for a CXL device as it is
22  * defined by the Compute Express Link specification. CXL devices may surface
23  * certain functionality even if it isn't CXL enabled. While this driver is
24  * focused around the PCI specific aspects of a CXL device, it binds to the
25  * specific CXL memory device class code, and therefore the implementation of
26  * cxl_pci is focused around CXL memory devices.
27  *
28  * The driver has several responsibilities, mainly:
29  *  - Create the memX device and register on the CXL bus.
30  *  - Enumerate device's register interface and map them.
31  *  - Registers nvdimm bridge device with cxl_core.
32  *  - Registers a CXL mailbox with cxl_core.
33  */
34 
35 #define cxl_doorbell_busy(cxlds)                                                \
36 	(readl((cxlds)->regs.mbox + CXLDEV_MBOX_CTRL_OFFSET) &                  \
37 	 CXLDEV_MBOX_CTRL_DOORBELL)
38 
39 /* CXL 2.0 - 8.2.8.4 */
40 #define CXL_MAILBOX_TIMEOUT_MS (2 * HZ)
41 
42 /*
43  * CXL 2.0 ECN "Add Mailbox Ready Time" defines a capability field to
44  * dictate how long to wait for the mailbox to become ready. The new
45  * field allows the device to tell software the amount of time to wait
46  * before mailbox ready. This field per the spec theoretically allows
47  * for up to 255 seconds. 255 seconds is unreasonably long, its longer
48  * than the maximum SATA port link recovery wait. Default to 60 seconds
49  * until someone builds a CXL device that needs more time in practice.
50  */
51 static unsigned short mbox_ready_timeout = 60;
52 module_param(mbox_ready_timeout, ushort, 0644);
53 MODULE_PARM_DESC(mbox_ready_timeout, "seconds to wait for mailbox ready");
54 
55 static int cxl_pci_mbox_wait_for_doorbell(struct cxl_dev_state *cxlds)
56 {
57 	const unsigned long start = jiffies;
58 	unsigned long end = start;
59 
60 	while (cxl_doorbell_busy(cxlds)) {
61 		end = jiffies;
62 
63 		if (time_after(end, start + CXL_MAILBOX_TIMEOUT_MS)) {
64 			/* Check again in case preempted before timeout test */
65 			if (!cxl_doorbell_busy(cxlds))
66 				break;
67 			return -ETIMEDOUT;
68 		}
69 		cpu_relax();
70 	}
71 
72 	dev_dbg(cxlds->dev, "Doorbell wait took %dms",
73 		jiffies_to_msecs(end) - jiffies_to_msecs(start));
74 	return 0;
75 }
76 
77 #define cxl_err(dev, status, msg)                                        \
78 	dev_err_ratelimited(dev, msg ", device state %s%s\n",                  \
79 			    status & CXLMDEV_DEV_FATAL ? " fatal" : "",        \
80 			    status & CXLMDEV_FW_HALT ? " firmware-halt" : "")
81 
82 #define cxl_cmd_err(dev, cmd, status, msg)                               \
83 	dev_err_ratelimited(dev, msg " (opcode: %#x), device state %s%s\n",    \
84 			    (cmd)->opcode,                                     \
85 			    status & CXLMDEV_DEV_FATAL ? " fatal" : "",        \
86 			    status & CXLMDEV_FW_HALT ? " firmware-halt" : "")
87 
88 /**
89  * __cxl_pci_mbox_send_cmd() - Execute a mailbox command
90  * @cxlds: The device state to communicate with.
91  * @mbox_cmd: Command to send to the memory device.
92  *
93  * Context: Any context. Expects mbox_mutex to be held.
94  * Return: -ETIMEDOUT if timeout occurred waiting for completion. 0 on success.
95  *         Caller should check the return code in @mbox_cmd to make sure it
96  *         succeeded.
97  *
98  * This is a generic form of the CXL mailbox send command thus only using the
99  * registers defined by the mailbox capability ID - CXL 2.0 8.2.8.4. Memory
100  * devices, and perhaps other types of CXL devices may have further information
101  * available upon error conditions. Driver facilities wishing to send mailbox
102  * commands should use the wrapper command.
103  *
104  * The CXL spec allows for up to two mailboxes. The intention is for the primary
105  * mailbox to be OS controlled and the secondary mailbox to be used by system
106  * firmware. This allows the OS and firmware to communicate with the device and
107  * not need to coordinate with each other. The driver only uses the primary
108  * mailbox.
109  */
110 static int __cxl_pci_mbox_send_cmd(struct cxl_dev_state *cxlds,
111 				   struct cxl_mbox_cmd *mbox_cmd)
112 {
113 	void __iomem *payload = cxlds->regs.mbox + CXLDEV_MBOX_PAYLOAD_OFFSET;
114 	struct device *dev = cxlds->dev;
115 	u64 cmd_reg, status_reg;
116 	size_t out_len;
117 	int rc;
118 
119 	lockdep_assert_held(&cxlds->mbox_mutex);
120 
121 	/*
122 	 * Here are the steps from 8.2.8.4 of the CXL 2.0 spec.
123 	 *   1. Caller reads MB Control Register to verify doorbell is clear
124 	 *   2. Caller writes Command Register
125 	 *   3. Caller writes Command Payload Registers if input payload is non-empty
126 	 *   4. Caller writes MB Control Register to set doorbell
127 	 *   5. Caller either polls for doorbell to be clear or waits for interrupt if configured
128 	 *   6. Caller reads MB Status Register to fetch Return code
129 	 *   7. If command successful, Caller reads Command Register to get Payload Length
130 	 *   8. If output payload is non-empty, host reads Command Payload Registers
131 	 *
132 	 * Hardware is free to do whatever it wants before the doorbell is rung,
133 	 * and isn't allowed to change anything after it clears the doorbell. As
134 	 * such, steps 2 and 3 can happen in any order, and steps 6, 7, 8 can
135 	 * also happen in any order (though some orders might not make sense).
136 	 */
137 
138 	/* #1 */
139 	if (cxl_doorbell_busy(cxlds)) {
140 		u64 md_status =
141 			readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
142 
143 		cxl_cmd_err(cxlds->dev, mbox_cmd, md_status,
144 			    "mailbox queue busy");
145 		return -EBUSY;
146 	}
147 
148 	cmd_reg = FIELD_PREP(CXLDEV_MBOX_CMD_COMMAND_OPCODE_MASK,
149 			     mbox_cmd->opcode);
150 	if (mbox_cmd->size_in) {
151 		if (WARN_ON(!mbox_cmd->payload_in))
152 			return -EINVAL;
153 
154 		cmd_reg |= FIELD_PREP(CXLDEV_MBOX_CMD_PAYLOAD_LENGTH_MASK,
155 				      mbox_cmd->size_in);
156 		memcpy_toio(payload, mbox_cmd->payload_in, mbox_cmd->size_in);
157 	}
158 
159 	/* #2, #3 */
160 	writeq(cmd_reg, cxlds->regs.mbox + CXLDEV_MBOX_CMD_OFFSET);
161 
162 	/* #4 */
163 	dev_dbg(dev, "Sending command: 0x%04x\n", mbox_cmd->opcode);
164 	writel(CXLDEV_MBOX_CTRL_DOORBELL,
165 	       cxlds->regs.mbox + CXLDEV_MBOX_CTRL_OFFSET);
166 
167 	/* #5 */
168 	rc = cxl_pci_mbox_wait_for_doorbell(cxlds);
169 	if (rc == -ETIMEDOUT) {
170 		u64 md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
171 
172 		cxl_cmd_err(cxlds->dev, mbox_cmd, md_status, "mailbox timeout");
173 		return rc;
174 	}
175 
176 	/* #6 */
177 	status_reg = readq(cxlds->regs.mbox + CXLDEV_MBOX_STATUS_OFFSET);
178 	mbox_cmd->return_code =
179 		FIELD_GET(CXLDEV_MBOX_STATUS_RET_CODE_MASK, status_reg);
180 
181 	if (mbox_cmd->return_code != CXL_MBOX_CMD_RC_SUCCESS) {
182 		dev_dbg(dev, "Mailbox operation had an error: %s\n",
183 			cxl_mbox_cmd_rc2str(mbox_cmd));
184 		return 0; /* completed but caller must check return_code */
185 	}
186 
187 	/* #7 */
188 	cmd_reg = readq(cxlds->regs.mbox + CXLDEV_MBOX_CMD_OFFSET);
189 	out_len = FIELD_GET(CXLDEV_MBOX_CMD_PAYLOAD_LENGTH_MASK, cmd_reg);
190 
191 	/* #8 */
192 	if (out_len && mbox_cmd->payload_out) {
193 		/*
194 		 * Sanitize the copy. If hardware misbehaves, out_len per the
195 		 * spec can actually be greater than the max allowed size (21
196 		 * bits available but spec defined 1M max). The caller also may
197 		 * have requested less data than the hardware supplied even
198 		 * within spec.
199 		 */
200 		size_t n = min3(mbox_cmd->size_out, cxlds->payload_size, out_len);
201 
202 		memcpy_fromio(mbox_cmd->payload_out, payload, n);
203 		mbox_cmd->size_out = n;
204 	} else {
205 		mbox_cmd->size_out = 0;
206 	}
207 
208 	return 0;
209 }
210 
211 static int cxl_pci_mbox_send(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
212 {
213 	int rc;
214 
215 	mutex_lock_io(&cxlds->mbox_mutex);
216 	rc = __cxl_pci_mbox_send_cmd(cxlds, cmd);
217 	mutex_unlock(&cxlds->mbox_mutex);
218 
219 	return rc;
220 }
221 
222 static int cxl_pci_setup_mailbox(struct cxl_dev_state *cxlds)
223 {
224 	const int cap = readl(cxlds->regs.mbox + CXLDEV_MBOX_CAPS_OFFSET);
225 	unsigned long timeout;
226 	u64 md_status;
227 
228 	timeout = jiffies + mbox_ready_timeout * HZ;
229 	do {
230 		md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
231 		if (md_status & CXLMDEV_MBOX_IF_READY)
232 			break;
233 		if (msleep_interruptible(100))
234 			break;
235 	} while (!time_after(jiffies, timeout));
236 
237 	if (!(md_status & CXLMDEV_MBOX_IF_READY)) {
238 		cxl_err(cxlds->dev, md_status,
239 			"timeout awaiting mailbox ready");
240 		return -ETIMEDOUT;
241 	}
242 
243 	/*
244 	 * A command may be in flight from a previous driver instance,
245 	 * think kexec, do one doorbell wait so that
246 	 * __cxl_pci_mbox_send_cmd() can assume that it is the only
247 	 * source for future doorbell busy events.
248 	 */
249 	if (cxl_pci_mbox_wait_for_doorbell(cxlds) != 0) {
250 		cxl_err(cxlds->dev, md_status, "timeout awaiting mailbox idle");
251 		return -ETIMEDOUT;
252 	}
253 
254 	cxlds->mbox_send = cxl_pci_mbox_send;
255 	cxlds->payload_size =
256 		1 << FIELD_GET(CXLDEV_MBOX_CAP_PAYLOAD_SIZE_MASK, cap);
257 
258 	/*
259 	 * CXL 2.0 8.2.8.4.3 Mailbox Capabilities Register
260 	 *
261 	 * If the size is too small, mandatory commands will not work and so
262 	 * there's no point in going forward. If the size is too large, there's
263 	 * no harm is soft limiting it.
264 	 */
265 	cxlds->payload_size = min_t(size_t, cxlds->payload_size, SZ_1M);
266 	if (cxlds->payload_size < 256) {
267 		dev_err(cxlds->dev, "Mailbox is too small (%zub)",
268 			cxlds->payload_size);
269 		return -ENXIO;
270 	}
271 
272 	dev_dbg(cxlds->dev, "Mailbox payload sized %zu",
273 		cxlds->payload_size);
274 
275 	return 0;
276 }
277 
278 static int cxl_map_regblock(struct pci_dev *pdev, struct cxl_register_map *map)
279 {
280 	struct device *dev = &pdev->dev;
281 
282 	map->base = ioremap(map->resource, map->max_size);
283 	if (!map->base) {
284 		dev_err(dev, "failed to map registers\n");
285 		return -ENOMEM;
286 	}
287 
288 	dev_dbg(dev, "Mapped CXL Memory Device resource %pa\n", &map->resource);
289 	return 0;
290 }
291 
292 static void cxl_unmap_regblock(struct pci_dev *pdev,
293 			       struct cxl_register_map *map)
294 {
295 	iounmap(map->base);
296 	map->base = NULL;
297 }
298 
299 static int cxl_probe_regs(struct pci_dev *pdev, struct cxl_register_map *map)
300 {
301 	struct cxl_component_reg_map *comp_map;
302 	struct cxl_device_reg_map *dev_map;
303 	struct device *dev = &pdev->dev;
304 	void __iomem *base = map->base;
305 
306 	switch (map->reg_type) {
307 	case CXL_REGLOC_RBI_COMPONENT:
308 		comp_map = &map->component_map;
309 		cxl_probe_component_regs(dev, base, comp_map);
310 		if (!comp_map->hdm_decoder.valid) {
311 			dev_err(dev, "HDM decoder registers not found\n");
312 			return -ENXIO;
313 		}
314 
315 		if (!comp_map->ras.valid)
316 			dev_dbg(dev, "RAS registers not found\n");
317 
318 		dev_dbg(dev, "Set up component registers\n");
319 		break;
320 	case CXL_REGLOC_RBI_MEMDEV:
321 		dev_map = &map->device_map;
322 		cxl_probe_device_regs(dev, base, dev_map);
323 		if (!dev_map->status.valid || !dev_map->mbox.valid ||
324 		    !dev_map->memdev.valid) {
325 			dev_err(dev, "registers not found: %s%s%s\n",
326 				!dev_map->status.valid ? "status " : "",
327 				!dev_map->mbox.valid ? "mbox " : "",
328 				!dev_map->memdev.valid ? "memdev " : "");
329 			return -ENXIO;
330 		}
331 
332 		dev_dbg(dev, "Probing device registers...\n");
333 		break;
334 	default:
335 		break;
336 	}
337 
338 	return 0;
339 }
340 
341 static int cxl_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
342 			  struct cxl_register_map *map)
343 {
344 	int rc;
345 
346 	rc = cxl_find_regblock(pdev, type, map);
347 	if (rc)
348 		return rc;
349 
350 	rc = cxl_map_regblock(pdev, map);
351 	if (rc)
352 		return rc;
353 
354 	rc = cxl_probe_regs(pdev, map);
355 	cxl_unmap_regblock(pdev, map);
356 
357 	return rc;
358 }
359 
360 static void cxl_pci_destroy_doe(void *mbs)
361 {
362 	xa_destroy(mbs);
363 }
364 
365 static void devm_cxl_pci_create_doe(struct cxl_dev_state *cxlds)
366 {
367 	struct device *dev = cxlds->dev;
368 	struct pci_dev *pdev = to_pci_dev(dev);
369 	u16 off = 0;
370 
371 	xa_init(&cxlds->doe_mbs);
372 	if (devm_add_action(&pdev->dev, cxl_pci_destroy_doe, &cxlds->doe_mbs)) {
373 		dev_err(dev, "Failed to create XArray for DOE's\n");
374 		return;
375 	}
376 
377 	/*
378 	 * Mailbox creation is best effort.  Higher layers must determine if
379 	 * the lack of a mailbox for their protocol is a device failure or not.
380 	 */
381 	pci_doe_for_each_off(pdev, off) {
382 		struct pci_doe_mb *doe_mb;
383 
384 		doe_mb = pcim_doe_create_mb(pdev, off);
385 		if (IS_ERR(doe_mb)) {
386 			dev_err(dev, "Failed to create MB object for MB @ %x\n",
387 				off);
388 			continue;
389 		}
390 
391 		if (!pci_request_config_region_exclusive(pdev, off,
392 							 PCI_DOE_CAP_SIZEOF,
393 							 dev_name(dev)))
394 			pci_err(pdev, "Failed to exclude DOE registers\n");
395 
396 		if (xa_insert(&cxlds->doe_mbs, off, doe_mb, GFP_KERNEL)) {
397 			dev_err(dev, "xa_insert failed to insert MB @ %x\n",
398 				off);
399 			continue;
400 		}
401 
402 		dev_dbg(dev, "Created DOE mailbox @%x\n", off);
403 	}
404 }
405 
406 /*
407  * Assume that any RCIEP that emits the CXL memory expander class code
408  * is an RCD
409  */
410 static bool is_cxl_restricted(struct pci_dev *pdev)
411 {
412 	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
413 }
414 
415 /*
416  * CXL v3.0 6.2.3 Table 6-4
417  * The table indicates that if PCIe Flit Mode is set, then CXL is in 256B flits
418  * mode, otherwise it's 68B flits mode.
419  */
420 static bool cxl_pci_flit_256(struct pci_dev *pdev)
421 {
422 	u16 lnksta2;
423 
424 	pcie_capability_read_word(pdev, PCI_EXP_LNKSTA2, &lnksta2);
425 	return lnksta2 & PCI_EXP_LNKSTA2_FLIT;
426 }
427 
428 static int cxl_pci_ras_unmask(struct pci_dev *pdev)
429 {
430 	struct pci_host_bridge *host_bridge = pci_find_host_bridge(pdev->bus);
431 	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
432 	void __iomem *addr;
433 	u32 orig_val, val, mask;
434 	u16 cap;
435 	int rc;
436 
437 	if (!cxlds->regs.ras) {
438 		dev_dbg(&pdev->dev, "No RAS registers.\n");
439 		return 0;
440 	}
441 
442 	/* BIOS has CXL error control */
443 	if (!host_bridge->native_cxl_error)
444 		return -ENXIO;
445 
446 	rc = pcie_capability_read_word(pdev, PCI_EXP_DEVCTL, &cap);
447 	if (rc)
448 		return rc;
449 
450 	if (cap & PCI_EXP_DEVCTL_URRE) {
451 		addr = cxlds->regs.ras + CXL_RAS_UNCORRECTABLE_MASK_OFFSET;
452 		orig_val = readl(addr);
453 
454 		mask = CXL_RAS_UNCORRECTABLE_MASK_MASK;
455 		if (!cxl_pci_flit_256(pdev))
456 			mask &= ~CXL_RAS_UNCORRECTABLE_MASK_F256B_MASK;
457 		val = orig_val & ~mask;
458 		writel(val, addr);
459 		dev_dbg(&pdev->dev,
460 			"Uncorrectable RAS Errors Mask: %#x -> %#x\n",
461 			orig_val, val);
462 	}
463 
464 	if (cap & PCI_EXP_DEVCTL_CERE) {
465 		addr = cxlds->regs.ras + CXL_RAS_CORRECTABLE_MASK_OFFSET;
466 		orig_val = readl(addr);
467 		val = orig_val & ~CXL_RAS_CORRECTABLE_MASK_MASK;
468 		writel(val, addr);
469 		dev_dbg(&pdev->dev, "Correctable RAS Errors Mask: %#x -> %#x\n",
470 			orig_val, val);
471 	}
472 
473 	return 0;
474 }
475 
476 static void free_event_buf(void *buf)
477 {
478 	kvfree(buf);
479 }
480 
481 /*
482  * There is a single buffer for reading event logs from the mailbox.  All logs
483  * share this buffer protected by the cxlds->event_log_lock.
484  */
485 static int cxl_mem_alloc_event_buf(struct cxl_dev_state *cxlds)
486 {
487 	struct cxl_get_event_payload *buf;
488 
489 	buf = kvmalloc(cxlds->payload_size, GFP_KERNEL);
490 	if (!buf)
491 		return -ENOMEM;
492 	cxlds->event.buf = buf;
493 
494 	return devm_add_action_or_reset(cxlds->dev, free_event_buf, buf);
495 }
496 
497 static int cxl_alloc_irq_vectors(struct pci_dev *pdev)
498 {
499 	int nvecs;
500 
501 	/*
502 	 * Per CXL 3.0 3.1.1 CXL.io Endpoint a function on a CXL device must
503 	 * not generate INTx messages if that function participates in
504 	 * CXL.cache or CXL.mem.
505 	 *
506 	 * Additionally pci_alloc_irq_vectors() handles calling
507 	 * pci_free_irq_vectors() automatically despite not being called
508 	 * pcim_*.  See pci_setup_msi_context().
509 	 */
510 	nvecs = pci_alloc_irq_vectors(pdev, 1, CXL_PCI_DEFAULT_MAX_VECTORS,
511 				      PCI_IRQ_MSIX | PCI_IRQ_MSI);
512 	if (nvecs < 1) {
513 		dev_dbg(&pdev->dev, "Failed to alloc irq vectors: %d\n", nvecs);
514 		return -ENXIO;
515 	}
516 	return 0;
517 }
518 
519 struct cxl_dev_id {
520 	struct cxl_dev_state *cxlds;
521 };
522 
523 static irqreturn_t cxl_event_thread(int irq, void *id)
524 {
525 	struct cxl_dev_id *dev_id = id;
526 	struct cxl_dev_state *cxlds = dev_id->cxlds;
527 	u32 status;
528 
529 	do {
530 		/*
531 		 * CXL 3.0 8.2.8.3.1: The lower 32 bits are the status;
532 		 * ignore the reserved upper 32 bits
533 		 */
534 		status = readl(cxlds->regs.status + CXLDEV_DEV_EVENT_STATUS_OFFSET);
535 		/* Ignore logs unknown to the driver */
536 		status &= CXLDEV_EVENT_STATUS_ALL;
537 		if (!status)
538 			break;
539 		cxl_mem_get_event_records(cxlds, status);
540 		cond_resched();
541 	} while (status);
542 
543 	return IRQ_HANDLED;
544 }
545 
546 static int cxl_event_req_irq(struct cxl_dev_state *cxlds, u8 setting)
547 {
548 	struct device *dev = cxlds->dev;
549 	struct pci_dev *pdev = to_pci_dev(dev);
550 	struct cxl_dev_id *dev_id;
551 	int irq;
552 
553 	if (FIELD_GET(CXLDEV_EVENT_INT_MODE_MASK, setting) != CXL_INT_MSI_MSIX)
554 		return -ENXIO;
555 
556 	/* dev_id must be globally unique and must contain the cxlds */
557 	dev_id = devm_kzalloc(dev, sizeof(*dev_id), GFP_KERNEL);
558 	if (!dev_id)
559 		return -ENOMEM;
560 	dev_id->cxlds = cxlds;
561 
562 	irq =  pci_irq_vector(pdev,
563 			      FIELD_GET(CXLDEV_EVENT_INT_MSGNUM_MASK, setting));
564 	if (irq < 0)
565 		return irq;
566 
567 	return devm_request_threaded_irq(dev, irq, NULL, cxl_event_thread,
568 					 IRQF_SHARED | IRQF_ONESHOT, NULL,
569 					 dev_id);
570 }
571 
572 static int cxl_event_get_int_policy(struct cxl_dev_state *cxlds,
573 				    struct cxl_event_interrupt_policy *policy)
574 {
575 	struct cxl_mbox_cmd mbox_cmd = {
576 		.opcode = CXL_MBOX_OP_GET_EVT_INT_POLICY,
577 		.payload_out = policy,
578 		.size_out = sizeof(*policy),
579 	};
580 	int rc;
581 
582 	rc = cxl_internal_send_cmd(cxlds, &mbox_cmd);
583 	if (rc < 0)
584 		dev_err(cxlds->dev, "Failed to get event interrupt policy : %d",
585 			rc);
586 
587 	return rc;
588 }
589 
590 static int cxl_event_config_msgnums(struct cxl_dev_state *cxlds,
591 				    struct cxl_event_interrupt_policy *policy)
592 {
593 	struct cxl_mbox_cmd mbox_cmd;
594 	int rc;
595 
596 	*policy = (struct cxl_event_interrupt_policy) {
597 		.info_settings = CXL_INT_MSI_MSIX,
598 		.warn_settings = CXL_INT_MSI_MSIX,
599 		.failure_settings = CXL_INT_MSI_MSIX,
600 		.fatal_settings = CXL_INT_MSI_MSIX,
601 	};
602 
603 	mbox_cmd = (struct cxl_mbox_cmd) {
604 		.opcode = CXL_MBOX_OP_SET_EVT_INT_POLICY,
605 		.payload_in = policy,
606 		.size_in = sizeof(*policy),
607 	};
608 
609 	rc = cxl_internal_send_cmd(cxlds, &mbox_cmd);
610 	if (rc < 0) {
611 		dev_err(cxlds->dev, "Failed to set event interrupt policy : %d",
612 			rc);
613 		return rc;
614 	}
615 
616 	/* Retrieve final interrupt settings */
617 	return cxl_event_get_int_policy(cxlds, policy);
618 }
619 
620 static int cxl_event_irqsetup(struct cxl_dev_state *cxlds)
621 {
622 	struct cxl_event_interrupt_policy policy;
623 	int rc;
624 
625 	rc = cxl_event_config_msgnums(cxlds, &policy);
626 	if (rc)
627 		return rc;
628 
629 	rc = cxl_event_req_irq(cxlds, policy.info_settings);
630 	if (rc) {
631 		dev_err(cxlds->dev, "Failed to get interrupt for event Info log\n");
632 		return rc;
633 	}
634 
635 	rc = cxl_event_req_irq(cxlds, policy.warn_settings);
636 	if (rc) {
637 		dev_err(cxlds->dev, "Failed to get interrupt for event Warn log\n");
638 		return rc;
639 	}
640 
641 	rc = cxl_event_req_irq(cxlds, policy.failure_settings);
642 	if (rc) {
643 		dev_err(cxlds->dev, "Failed to get interrupt for event Failure log\n");
644 		return rc;
645 	}
646 
647 	rc = cxl_event_req_irq(cxlds, policy.fatal_settings);
648 	if (rc) {
649 		dev_err(cxlds->dev, "Failed to get interrupt for event Fatal log\n");
650 		return rc;
651 	}
652 
653 	return 0;
654 }
655 
656 static bool cxl_event_int_is_fw(u8 setting)
657 {
658 	u8 mode = FIELD_GET(CXLDEV_EVENT_INT_MODE_MASK, setting);
659 
660 	return mode == CXL_INT_FW;
661 }
662 
663 static int cxl_event_config(struct pci_host_bridge *host_bridge,
664 			    struct cxl_dev_state *cxlds)
665 {
666 	struct cxl_event_interrupt_policy policy;
667 	int rc;
668 
669 	/*
670 	 * When BIOS maintains CXL error reporting control, it will process
671 	 * event records.  Only one agent can do so.
672 	 */
673 	if (!host_bridge->native_cxl_error)
674 		return 0;
675 
676 	rc = cxl_mem_alloc_event_buf(cxlds);
677 	if (rc)
678 		return rc;
679 
680 	rc = cxl_event_get_int_policy(cxlds, &policy);
681 	if (rc)
682 		return rc;
683 
684 	if (cxl_event_int_is_fw(policy.info_settings) ||
685 	    cxl_event_int_is_fw(policy.warn_settings) ||
686 	    cxl_event_int_is_fw(policy.failure_settings) ||
687 	    cxl_event_int_is_fw(policy.fatal_settings)) {
688 		dev_err(cxlds->dev, "FW still in control of Event Logs despite _OSC settings\n");
689 		return -EBUSY;
690 	}
691 
692 	rc = cxl_event_irqsetup(cxlds);
693 	if (rc)
694 		return rc;
695 
696 	cxl_mem_get_event_records(cxlds, CXLDEV_EVENT_STATUS_ALL);
697 
698 	return 0;
699 }
700 
701 static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
702 {
703 	struct pci_host_bridge *host_bridge = pci_find_host_bridge(pdev->bus);
704 	struct cxl_register_map map;
705 	struct cxl_memdev *cxlmd;
706 	struct cxl_dev_state *cxlds;
707 	int rc;
708 
709 	/*
710 	 * Double check the anonymous union trickery in struct cxl_regs
711 	 * FIXME switch to struct_group()
712 	 */
713 	BUILD_BUG_ON(offsetof(struct cxl_regs, memdev) !=
714 		     offsetof(struct cxl_regs, device_regs.memdev));
715 
716 	rc = pcim_enable_device(pdev);
717 	if (rc)
718 		return rc;
719 	pci_set_master(pdev);
720 
721 	cxlds = cxl_dev_state_create(&pdev->dev);
722 	if (IS_ERR(cxlds))
723 		return PTR_ERR(cxlds);
724 	pci_set_drvdata(pdev, cxlds);
725 
726 	cxlds->rcd = is_cxl_restricted(pdev);
727 	cxlds->serial = pci_get_dsn(pdev);
728 	cxlds->cxl_dvsec = pci_find_dvsec_capability(
729 		pdev, PCI_DVSEC_VENDOR_ID_CXL, CXL_DVSEC_PCIE_DEVICE);
730 	if (!cxlds->cxl_dvsec)
731 		dev_warn(&pdev->dev,
732 			 "Device DVSEC not present, skip CXL.mem init\n");
733 
734 	rc = cxl_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map);
735 	if (rc)
736 		return rc;
737 
738 	rc = cxl_map_device_regs(&pdev->dev, &cxlds->regs.device_regs, &map);
739 	if (rc)
740 		return rc;
741 
742 	/*
743 	 * If the component registers can't be found, the cxl_pci driver may
744 	 * still be useful for management functions so don't return an error.
745 	 */
746 	cxlds->component_reg_phys = CXL_RESOURCE_NONE;
747 	rc = cxl_setup_regs(pdev, CXL_REGLOC_RBI_COMPONENT, &map);
748 	if (rc)
749 		dev_warn(&pdev->dev, "No component registers (%d)\n", rc);
750 
751 	cxlds->component_reg_phys = map.resource;
752 
753 	devm_cxl_pci_create_doe(cxlds);
754 
755 	rc = cxl_map_component_regs(&pdev->dev, &cxlds->regs.component,
756 				    &map, BIT(CXL_CM_CAP_CAP_ID_RAS));
757 	if (rc)
758 		dev_dbg(&pdev->dev, "Failed to map RAS capability.\n");
759 
760 	rc = cxl_pci_setup_mailbox(cxlds);
761 	if (rc)
762 		return rc;
763 
764 	rc = cxl_enumerate_cmds(cxlds);
765 	if (rc)
766 		return rc;
767 
768 	rc = cxl_set_timestamp(cxlds);
769 	if (rc)
770 		return rc;
771 
772 	rc = cxl_dev_state_identify(cxlds);
773 	if (rc)
774 		return rc;
775 
776 	rc = cxl_mem_create_range_info(cxlds);
777 	if (rc)
778 		return rc;
779 
780 	rc = cxl_alloc_irq_vectors(pdev);
781 	if (rc)
782 		return rc;
783 
784 	cxlmd = devm_cxl_add_memdev(cxlds);
785 	if (IS_ERR(cxlmd))
786 		return PTR_ERR(cxlmd);
787 
788 	rc = cxl_event_config(host_bridge, cxlds);
789 	if (rc)
790 		return rc;
791 
792 	rc = cxl_pci_ras_unmask(pdev);
793 	if (rc)
794 		dev_dbg(&pdev->dev, "No RAS reporting unmasked\n");
795 
796 	pci_save_state(pdev);
797 
798 	return rc;
799 }
800 
801 static const struct pci_device_id cxl_mem_pci_tbl[] = {
802 	/* PCI class code for CXL.mem Type-3 Devices */
803 	{ PCI_DEVICE_CLASS((PCI_CLASS_MEMORY_CXL << 8 | CXL_MEMORY_PROGIF), ~0)},
804 	{ /* terminate list */ },
805 };
806 MODULE_DEVICE_TABLE(pci, cxl_mem_pci_tbl);
807 
808 static pci_ers_result_t cxl_slot_reset(struct pci_dev *pdev)
809 {
810 	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
811 	struct cxl_memdev *cxlmd = cxlds->cxlmd;
812 	struct device *dev = &cxlmd->dev;
813 
814 	dev_info(&pdev->dev, "%s: restart CXL.mem after slot reset\n",
815 		 dev_name(dev));
816 	pci_restore_state(pdev);
817 	if (device_attach(dev) <= 0)
818 		return PCI_ERS_RESULT_DISCONNECT;
819 	return PCI_ERS_RESULT_RECOVERED;
820 }
821 
822 static void cxl_error_resume(struct pci_dev *pdev)
823 {
824 	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
825 	struct cxl_memdev *cxlmd = cxlds->cxlmd;
826 	struct device *dev = &cxlmd->dev;
827 
828 	dev_info(&pdev->dev, "%s: error resume %s\n", dev_name(dev),
829 		 dev->driver ? "successful" : "failed");
830 }
831 
832 static const struct pci_error_handlers cxl_error_handlers = {
833 	.error_detected	= cxl_error_detected,
834 	.slot_reset	= cxl_slot_reset,
835 	.resume		= cxl_error_resume,
836 	.cor_error_detected	= cxl_cor_error_detected,
837 };
838 
839 static struct pci_driver cxl_pci_driver = {
840 	.name			= KBUILD_MODNAME,
841 	.id_table		= cxl_mem_pci_tbl,
842 	.probe			= cxl_pci_probe,
843 	.err_handler		= &cxl_error_handlers,
844 	.driver	= {
845 		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
846 	},
847 };
848 
849 MODULE_LICENSE("GPL v2");
850 module_pci_driver(cxl_pci_driver);
851 MODULE_IMPORT_NS(CXL);
852