xref: /openbmc/linux/drivers/cxl/pci.c (revision 59f8d1510739e92135df62d52e8c29bc075c46ad)
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/aer.h>
12 #include <linux/io.h>
13 #include "cxlmem.h"
14 #include "cxlpci.h"
15 #include "cxl.h"
16 
17 /**
18  * DOC: cxl pci
19  *
20  * This implements the PCI exclusive functionality for a CXL device as it is
21  * defined by the Compute Express Link specification. CXL devices may surface
22  * certain functionality even if it isn't CXL enabled. While this driver is
23  * focused around the PCI specific aspects of a CXL device, it binds to the
24  * specific CXL memory device class code, and therefore the implementation of
25  * cxl_pci is focused around CXL memory devices.
26  *
27  * The driver has several responsibilities, mainly:
28  *  - Create the memX device and register on the CXL bus.
29  *  - Enumerate device's register interface and map them.
30  *  - Registers nvdimm bridge device with cxl_core.
31  *  - Registers a CXL mailbox with cxl_core.
32  */
33 
34 #define cxl_doorbell_busy(cxlds)                                                \
35 	(readl((cxlds)->regs.mbox + CXLDEV_MBOX_CTRL_OFFSET) &                  \
36 	 CXLDEV_MBOX_CTRL_DOORBELL)
37 
38 /* CXL 2.0 - 8.2.8.4 */
39 #define CXL_MAILBOX_TIMEOUT_MS (2 * HZ)
40 
41 /*
42  * CXL 2.0 ECN "Add Mailbox Ready Time" defines a capability field to
43  * dictate how long to wait for the mailbox to become ready. The new
44  * field allows the device to tell software the amount of time to wait
45  * before mailbox ready. This field per the spec theoretically allows
46  * for up to 255 seconds. 255 seconds is unreasonably long, its longer
47  * than the maximum SATA port link recovery wait. Default to 60 seconds
48  * until someone builds a CXL device that needs more time in practice.
49  */
50 static unsigned short mbox_ready_timeout = 60;
51 module_param(mbox_ready_timeout, ushort, 0644);
52 MODULE_PARM_DESC(mbox_ready_timeout, "seconds to wait for mailbox ready");
53 
54 static int cxl_pci_mbox_wait_for_doorbell(struct cxl_dev_state *cxlds)
55 {
56 	const unsigned long start = jiffies;
57 	unsigned long end = start;
58 
59 	while (cxl_doorbell_busy(cxlds)) {
60 		end = jiffies;
61 
62 		if (time_after(end, start + CXL_MAILBOX_TIMEOUT_MS)) {
63 			/* Check again in case preempted before timeout test */
64 			if (!cxl_doorbell_busy(cxlds))
65 				break;
66 			return -ETIMEDOUT;
67 		}
68 		cpu_relax();
69 	}
70 
71 	dev_dbg(cxlds->dev, "Doorbell wait took %dms",
72 		jiffies_to_msecs(end) - jiffies_to_msecs(start));
73 	return 0;
74 }
75 
76 #define cxl_err(dev, status, msg)                                        \
77 	dev_err_ratelimited(dev, msg ", device state %s%s\n",                  \
78 			    status & CXLMDEV_DEV_FATAL ? " fatal" : "",        \
79 			    status & CXLMDEV_FW_HALT ? " firmware-halt" : "")
80 
81 #define cxl_cmd_err(dev, cmd, status, msg)                               \
82 	dev_err_ratelimited(dev, msg " (opcode: %#x), device state %s%s\n",    \
83 			    (cmd)->opcode,                                     \
84 			    status & CXLMDEV_DEV_FATAL ? " fatal" : "",        \
85 			    status & CXLMDEV_FW_HALT ? " firmware-halt" : "")
86 
87 /**
88  * __cxl_pci_mbox_send_cmd() - Execute a mailbox command
89  * @mds: The memory device driver data
90  * @mbox_cmd: Command to send to the memory device.
91  *
92  * Context: Any context. Expects mbox_mutex to be held.
93  * Return: -ETIMEDOUT if timeout occurred waiting for completion. 0 on success.
94  *         Caller should check the return code in @mbox_cmd to make sure it
95  *         succeeded.
96  *
97  * This is a generic form of the CXL mailbox send command thus only using the
98  * registers defined by the mailbox capability ID - CXL 2.0 8.2.8.4. Memory
99  * devices, and perhaps other types of CXL devices may have further information
100  * available upon error conditions. Driver facilities wishing to send mailbox
101  * commands should use the wrapper command.
102  *
103  * The CXL spec allows for up to two mailboxes. The intention is for the primary
104  * mailbox to be OS controlled and the secondary mailbox to be used by system
105  * firmware. This allows the OS and firmware to communicate with the device and
106  * not need to coordinate with each other. The driver only uses the primary
107  * mailbox.
108  */
109 static int __cxl_pci_mbox_send_cmd(struct cxl_memdev_state *mds,
110 				   struct cxl_mbox_cmd *mbox_cmd)
111 {
112 	struct cxl_dev_state *cxlds = &mds->cxlds;
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(&mds->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;
201 
202 		n = min3(mbox_cmd->size_out, mds->payload_size, out_len);
203 		memcpy_fromio(mbox_cmd->payload_out, payload, n);
204 		mbox_cmd->size_out = n;
205 	} else {
206 		mbox_cmd->size_out = 0;
207 	}
208 
209 	return 0;
210 }
211 
212 static int cxl_pci_mbox_send(struct cxl_memdev_state *mds,
213 			     struct cxl_mbox_cmd *cmd)
214 {
215 	int rc;
216 
217 	mutex_lock_io(&mds->mbox_mutex);
218 	rc = __cxl_pci_mbox_send_cmd(mds, cmd);
219 	mutex_unlock(&mds->mbox_mutex);
220 
221 	return rc;
222 }
223 
224 static int cxl_pci_setup_mailbox(struct cxl_memdev_state *mds)
225 {
226 	struct cxl_dev_state *cxlds = &mds->cxlds;
227 	const int cap = readl(cxlds->regs.mbox + CXLDEV_MBOX_CAPS_OFFSET);
228 	struct device *dev = cxlds->dev;
229 	unsigned long timeout;
230 	u64 md_status;
231 
232 	timeout = jiffies + mbox_ready_timeout * HZ;
233 	do {
234 		md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
235 		if (md_status & CXLMDEV_MBOX_IF_READY)
236 			break;
237 		if (msleep_interruptible(100))
238 			break;
239 	} while (!time_after(jiffies, timeout));
240 
241 	if (!(md_status & CXLMDEV_MBOX_IF_READY)) {
242 		cxl_err(dev, md_status, "timeout awaiting mailbox ready");
243 		return -ETIMEDOUT;
244 	}
245 
246 	/*
247 	 * A command may be in flight from a previous driver instance,
248 	 * think kexec, do one doorbell wait so that
249 	 * __cxl_pci_mbox_send_cmd() can assume that it is the only
250 	 * source for future doorbell busy events.
251 	 */
252 	if (cxl_pci_mbox_wait_for_doorbell(cxlds) != 0) {
253 		cxl_err(dev, md_status, "timeout awaiting mailbox idle");
254 		return -ETIMEDOUT;
255 	}
256 
257 	mds->mbox_send = cxl_pci_mbox_send;
258 	mds->payload_size =
259 		1 << FIELD_GET(CXLDEV_MBOX_CAP_PAYLOAD_SIZE_MASK, cap);
260 
261 	/*
262 	 * CXL 2.0 8.2.8.4.3 Mailbox Capabilities Register
263 	 *
264 	 * If the size is too small, mandatory commands will not work and so
265 	 * there's no point in going forward. If the size is too large, there's
266 	 * no harm is soft limiting it.
267 	 */
268 	mds->payload_size = min_t(size_t, mds->payload_size, SZ_1M);
269 	if (mds->payload_size < 256) {
270 		dev_err(dev, "Mailbox is too small (%zub)",
271 			mds->payload_size);
272 		return -ENXIO;
273 	}
274 
275 	dev_dbg(dev, "Mailbox payload sized %zu", mds->payload_size);
276 
277 	return 0;
278 }
279 
280 static int cxl_map_regblock(struct pci_dev *pdev, struct cxl_register_map *map)
281 {
282 	struct device *dev = &pdev->dev;
283 
284 	map->base = ioremap(map->resource, map->max_size);
285 	if (!map->base) {
286 		dev_err(dev, "failed to map registers\n");
287 		return -ENOMEM;
288 	}
289 
290 	dev_dbg(dev, "Mapped CXL Memory Device resource %pa\n", &map->resource);
291 	return 0;
292 }
293 
294 static void cxl_unmap_regblock(struct pci_dev *pdev,
295 			       struct cxl_register_map *map)
296 {
297 	iounmap(map->base);
298 	map->base = NULL;
299 }
300 
301 static int cxl_probe_regs(struct pci_dev *pdev, struct cxl_register_map *map)
302 {
303 	struct cxl_component_reg_map *comp_map;
304 	struct cxl_device_reg_map *dev_map;
305 	struct device *dev = &pdev->dev;
306 	void __iomem *base = map->base;
307 
308 	switch (map->reg_type) {
309 	case CXL_REGLOC_RBI_COMPONENT:
310 		comp_map = &map->component_map;
311 		cxl_probe_component_regs(dev, base, comp_map);
312 		if (!comp_map->hdm_decoder.valid) {
313 			dev_err(dev, "HDM decoder registers not found\n");
314 			return -ENXIO;
315 		}
316 
317 		if (!comp_map->ras.valid)
318 			dev_dbg(dev, "RAS registers not found\n");
319 
320 		dev_dbg(dev, "Set up component registers\n");
321 		break;
322 	case CXL_REGLOC_RBI_MEMDEV:
323 		dev_map = &map->device_map;
324 		cxl_probe_device_regs(dev, base, dev_map);
325 		if (!dev_map->status.valid || !dev_map->mbox.valid ||
326 		    !dev_map->memdev.valid) {
327 			dev_err(dev, "registers not found: %s%s%s\n",
328 				!dev_map->status.valid ? "status " : "",
329 				!dev_map->mbox.valid ? "mbox " : "",
330 				!dev_map->memdev.valid ? "memdev " : "");
331 			return -ENXIO;
332 		}
333 
334 		dev_dbg(dev, "Probing device registers...\n");
335 		break;
336 	default:
337 		break;
338 	}
339 
340 	return 0;
341 }
342 
343 static int cxl_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
344 			  struct cxl_register_map *map)
345 {
346 	int rc;
347 
348 	rc = cxl_find_regblock(pdev, type, map);
349 	if (rc)
350 		return rc;
351 
352 	rc = cxl_map_regblock(pdev, map);
353 	if (rc)
354 		return rc;
355 
356 	rc = cxl_probe_regs(pdev, map);
357 	cxl_unmap_regblock(pdev, map);
358 
359 	return rc;
360 }
361 
362 /*
363  * Assume that any RCIEP that emits the CXL memory expander class code
364  * is an RCD
365  */
366 static bool is_cxl_restricted(struct pci_dev *pdev)
367 {
368 	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
369 }
370 
371 /*
372  * CXL v3.0 6.2.3 Table 6-4
373  * The table indicates that if PCIe Flit Mode is set, then CXL is in 256B flits
374  * mode, otherwise it's 68B flits mode.
375  */
376 static bool cxl_pci_flit_256(struct pci_dev *pdev)
377 {
378 	u16 lnksta2;
379 
380 	pcie_capability_read_word(pdev, PCI_EXP_LNKSTA2, &lnksta2);
381 	return lnksta2 & PCI_EXP_LNKSTA2_FLIT;
382 }
383 
384 static int cxl_pci_ras_unmask(struct pci_dev *pdev)
385 {
386 	struct pci_host_bridge *host_bridge = pci_find_host_bridge(pdev->bus);
387 	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
388 	void __iomem *addr;
389 	u32 orig_val, val, mask;
390 	u16 cap;
391 	int rc;
392 
393 	if (!cxlds->regs.ras) {
394 		dev_dbg(&pdev->dev, "No RAS registers.\n");
395 		return 0;
396 	}
397 
398 	/* BIOS has CXL error control */
399 	if (!host_bridge->native_cxl_error)
400 		return -ENXIO;
401 
402 	rc = pcie_capability_read_word(pdev, PCI_EXP_DEVCTL, &cap);
403 	if (rc)
404 		return rc;
405 
406 	if (cap & PCI_EXP_DEVCTL_URRE) {
407 		addr = cxlds->regs.ras + CXL_RAS_UNCORRECTABLE_MASK_OFFSET;
408 		orig_val = readl(addr);
409 
410 		mask = CXL_RAS_UNCORRECTABLE_MASK_MASK;
411 		if (!cxl_pci_flit_256(pdev))
412 			mask &= ~CXL_RAS_UNCORRECTABLE_MASK_F256B_MASK;
413 		val = orig_val & ~mask;
414 		writel(val, addr);
415 		dev_dbg(&pdev->dev,
416 			"Uncorrectable RAS Errors Mask: %#x -> %#x\n",
417 			orig_val, val);
418 	}
419 
420 	if (cap & PCI_EXP_DEVCTL_CERE) {
421 		addr = cxlds->regs.ras + CXL_RAS_CORRECTABLE_MASK_OFFSET;
422 		orig_val = readl(addr);
423 		val = orig_val & ~CXL_RAS_CORRECTABLE_MASK_MASK;
424 		writel(val, addr);
425 		dev_dbg(&pdev->dev, "Correctable RAS Errors Mask: %#x -> %#x\n",
426 			orig_val, val);
427 	}
428 
429 	return 0;
430 }
431 
432 static void free_event_buf(void *buf)
433 {
434 	kvfree(buf);
435 }
436 
437 /*
438  * There is a single buffer for reading event logs from the mailbox.  All logs
439  * share this buffer protected by the mds->event_log_lock.
440  */
441 static int cxl_mem_alloc_event_buf(struct cxl_memdev_state *mds)
442 {
443 	struct cxl_get_event_payload *buf;
444 
445 	buf = kvmalloc(mds->payload_size, GFP_KERNEL);
446 	if (!buf)
447 		return -ENOMEM;
448 	mds->event.buf = buf;
449 
450 	return devm_add_action_or_reset(mds->cxlds.dev, free_event_buf, buf);
451 }
452 
453 static int cxl_alloc_irq_vectors(struct pci_dev *pdev)
454 {
455 	int nvecs;
456 
457 	/*
458 	 * Per CXL 3.0 3.1.1 CXL.io Endpoint a function on a CXL device must
459 	 * not generate INTx messages if that function participates in
460 	 * CXL.cache or CXL.mem.
461 	 *
462 	 * Additionally pci_alloc_irq_vectors() handles calling
463 	 * pci_free_irq_vectors() automatically despite not being called
464 	 * pcim_*.  See pci_setup_msi_context().
465 	 */
466 	nvecs = pci_alloc_irq_vectors(pdev, 1, CXL_PCI_DEFAULT_MAX_VECTORS,
467 				      PCI_IRQ_MSIX | PCI_IRQ_MSI);
468 	if (nvecs < 1) {
469 		dev_dbg(&pdev->dev, "Failed to alloc irq vectors: %d\n", nvecs);
470 		return -ENXIO;
471 	}
472 	return 0;
473 }
474 
475 struct cxl_dev_id {
476 	struct cxl_dev_state *cxlds;
477 };
478 
479 static irqreturn_t cxl_event_thread(int irq, void *id)
480 {
481 	struct cxl_dev_id *dev_id = id;
482 	struct cxl_dev_state *cxlds = dev_id->cxlds;
483 	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds);
484 	u32 status;
485 
486 	do {
487 		/*
488 		 * CXL 3.0 8.2.8.3.1: The lower 32 bits are the status;
489 		 * ignore the reserved upper 32 bits
490 		 */
491 		status = readl(cxlds->regs.status + CXLDEV_DEV_EVENT_STATUS_OFFSET);
492 		/* Ignore logs unknown to the driver */
493 		status &= CXLDEV_EVENT_STATUS_ALL;
494 		if (!status)
495 			break;
496 		cxl_mem_get_event_records(mds, status);
497 		cond_resched();
498 	} while (status);
499 
500 	return IRQ_HANDLED;
501 }
502 
503 static int cxl_event_req_irq(struct cxl_dev_state *cxlds, u8 setting)
504 {
505 	struct device *dev = cxlds->dev;
506 	struct pci_dev *pdev = to_pci_dev(dev);
507 	struct cxl_dev_id *dev_id;
508 	int irq;
509 
510 	if (FIELD_GET(CXLDEV_EVENT_INT_MODE_MASK, setting) != CXL_INT_MSI_MSIX)
511 		return -ENXIO;
512 
513 	/* dev_id must be globally unique and must contain the cxlds */
514 	dev_id = devm_kzalloc(dev, sizeof(*dev_id), GFP_KERNEL);
515 	if (!dev_id)
516 		return -ENOMEM;
517 	dev_id->cxlds = cxlds;
518 
519 	irq =  pci_irq_vector(pdev,
520 			      FIELD_GET(CXLDEV_EVENT_INT_MSGNUM_MASK, setting));
521 	if (irq < 0)
522 		return irq;
523 
524 	return devm_request_threaded_irq(dev, irq, NULL, cxl_event_thread,
525 					 IRQF_SHARED | IRQF_ONESHOT, NULL,
526 					 dev_id);
527 }
528 
529 static int cxl_event_get_int_policy(struct cxl_memdev_state *mds,
530 				    struct cxl_event_interrupt_policy *policy)
531 {
532 	struct cxl_mbox_cmd mbox_cmd = {
533 		.opcode = CXL_MBOX_OP_GET_EVT_INT_POLICY,
534 		.payload_out = policy,
535 		.size_out = sizeof(*policy),
536 	};
537 	int rc;
538 
539 	rc = cxl_internal_send_cmd(mds, &mbox_cmd);
540 	if (rc < 0)
541 		dev_err(mds->cxlds.dev,
542 			"Failed to get event interrupt policy : %d", rc);
543 
544 	return rc;
545 }
546 
547 static int cxl_event_config_msgnums(struct cxl_memdev_state *mds,
548 				    struct cxl_event_interrupt_policy *policy)
549 {
550 	struct cxl_mbox_cmd mbox_cmd;
551 	int rc;
552 
553 	*policy = (struct cxl_event_interrupt_policy) {
554 		.info_settings = CXL_INT_MSI_MSIX,
555 		.warn_settings = CXL_INT_MSI_MSIX,
556 		.failure_settings = CXL_INT_MSI_MSIX,
557 		.fatal_settings = CXL_INT_MSI_MSIX,
558 	};
559 
560 	mbox_cmd = (struct cxl_mbox_cmd) {
561 		.opcode = CXL_MBOX_OP_SET_EVT_INT_POLICY,
562 		.payload_in = policy,
563 		.size_in = sizeof(*policy),
564 	};
565 
566 	rc = cxl_internal_send_cmd(mds, &mbox_cmd);
567 	if (rc < 0) {
568 		dev_err(mds->cxlds.dev, "Failed to set event interrupt policy : %d",
569 			rc);
570 		return rc;
571 	}
572 
573 	/* Retrieve final interrupt settings */
574 	return cxl_event_get_int_policy(mds, policy);
575 }
576 
577 static int cxl_event_irqsetup(struct cxl_memdev_state *mds)
578 {
579 	struct cxl_dev_state *cxlds = &mds->cxlds;
580 	struct cxl_event_interrupt_policy policy;
581 	int rc;
582 
583 	rc = cxl_event_config_msgnums(mds, &policy);
584 	if (rc)
585 		return rc;
586 
587 	rc = cxl_event_req_irq(cxlds, policy.info_settings);
588 	if (rc) {
589 		dev_err(cxlds->dev, "Failed to get interrupt for event Info log\n");
590 		return rc;
591 	}
592 
593 	rc = cxl_event_req_irq(cxlds, policy.warn_settings);
594 	if (rc) {
595 		dev_err(cxlds->dev, "Failed to get interrupt for event Warn log\n");
596 		return rc;
597 	}
598 
599 	rc = cxl_event_req_irq(cxlds, policy.failure_settings);
600 	if (rc) {
601 		dev_err(cxlds->dev, "Failed to get interrupt for event Failure log\n");
602 		return rc;
603 	}
604 
605 	rc = cxl_event_req_irq(cxlds, policy.fatal_settings);
606 	if (rc) {
607 		dev_err(cxlds->dev, "Failed to get interrupt for event Fatal log\n");
608 		return rc;
609 	}
610 
611 	return 0;
612 }
613 
614 static bool cxl_event_int_is_fw(u8 setting)
615 {
616 	u8 mode = FIELD_GET(CXLDEV_EVENT_INT_MODE_MASK, setting);
617 
618 	return mode == CXL_INT_FW;
619 }
620 
621 static int cxl_event_config(struct pci_host_bridge *host_bridge,
622 			    struct cxl_memdev_state *mds)
623 {
624 	struct cxl_event_interrupt_policy policy;
625 	int rc;
626 
627 	/*
628 	 * When BIOS maintains CXL error reporting control, it will process
629 	 * event records.  Only one agent can do so.
630 	 */
631 	if (!host_bridge->native_cxl_error)
632 		return 0;
633 
634 	rc = cxl_mem_alloc_event_buf(mds);
635 	if (rc)
636 		return rc;
637 
638 	rc = cxl_event_get_int_policy(mds, &policy);
639 	if (rc)
640 		return rc;
641 
642 	if (cxl_event_int_is_fw(policy.info_settings) ||
643 	    cxl_event_int_is_fw(policy.warn_settings) ||
644 	    cxl_event_int_is_fw(policy.failure_settings) ||
645 	    cxl_event_int_is_fw(policy.fatal_settings)) {
646 		dev_err(mds->cxlds.dev,
647 			"FW still in control of Event Logs despite _OSC settings\n");
648 		return -EBUSY;
649 	}
650 
651 	rc = cxl_event_irqsetup(mds);
652 	if (rc)
653 		return rc;
654 
655 	cxl_mem_get_event_records(mds, CXLDEV_EVENT_STATUS_ALL);
656 
657 	return 0;
658 }
659 
660 static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
661 {
662 	struct pci_host_bridge *host_bridge = pci_find_host_bridge(pdev->bus);
663 	struct cxl_memdev_state *mds;
664 	struct cxl_dev_state *cxlds;
665 	struct cxl_register_map map;
666 	struct cxl_memdev *cxlmd;
667 	int rc;
668 
669 	/*
670 	 * Double check the anonymous union trickery in struct cxl_regs
671 	 * FIXME switch to struct_group()
672 	 */
673 	BUILD_BUG_ON(offsetof(struct cxl_regs, memdev) !=
674 		     offsetof(struct cxl_regs, device_regs.memdev));
675 
676 	rc = pcim_enable_device(pdev);
677 	if (rc)
678 		return rc;
679 	pci_set_master(pdev);
680 
681 	mds = cxl_memdev_state_create(&pdev->dev);
682 	if (IS_ERR(mds))
683 		return PTR_ERR(mds);
684 	cxlds = &mds->cxlds;
685 	pci_set_drvdata(pdev, cxlds);
686 
687 	cxlds->rcd = is_cxl_restricted(pdev);
688 	cxlds->serial = pci_get_dsn(pdev);
689 	cxlds->cxl_dvsec = pci_find_dvsec_capability(
690 		pdev, PCI_DVSEC_VENDOR_ID_CXL, CXL_DVSEC_PCIE_DEVICE);
691 	if (!cxlds->cxl_dvsec)
692 		dev_warn(&pdev->dev,
693 			 "Device DVSEC not present, skip CXL.mem init\n");
694 
695 	rc = cxl_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map);
696 	if (rc)
697 		return rc;
698 
699 	rc = cxl_map_device_regs(&pdev->dev, &cxlds->regs.device_regs, &map);
700 	if (rc)
701 		return rc;
702 
703 	/*
704 	 * If the component registers can't be found, the cxl_pci driver may
705 	 * still be useful for management functions so don't return an error.
706 	 */
707 	cxlds->component_reg_phys = CXL_RESOURCE_NONE;
708 	rc = cxl_setup_regs(pdev, CXL_REGLOC_RBI_COMPONENT, &map);
709 	if (rc)
710 		dev_warn(&pdev->dev, "No component registers (%d)\n", rc);
711 
712 	cxlds->component_reg_phys = map.resource;
713 
714 	rc = cxl_map_component_regs(&pdev->dev, &cxlds->regs.component,
715 				    &map, BIT(CXL_CM_CAP_CAP_ID_RAS));
716 	if (rc)
717 		dev_dbg(&pdev->dev, "Failed to map RAS capability.\n");
718 
719 	rc = cxl_await_media_ready(cxlds);
720 	if (rc == 0)
721 		cxlds->media_ready = true;
722 	else
723 		dev_warn(&pdev->dev, "Media not active (%d)\n", rc);
724 
725 	rc = cxl_pci_setup_mailbox(mds);
726 	if (rc)
727 		return rc;
728 
729 	rc = cxl_enumerate_cmds(mds);
730 	if (rc)
731 		return rc;
732 
733 	rc = cxl_set_timestamp(mds);
734 	if (rc)
735 		return rc;
736 
737 	rc = cxl_poison_state_init(mds);
738 	if (rc)
739 		return rc;
740 
741 	rc = cxl_dev_state_identify(mds);
742 	if (rc)
743 		return rc;
744 
745 	rc = cxl_mem_create_range_info(mds);
746 	if (rc)
747 		return rc;
748 
749 	rc = cxl_alloc_irq_vectors(pdev);
750 	if (rc)
751 		return rc;
752 
753 	cxlmd = devm_cxl_add_memdev(cxlds);
754 	if (IS_ERR(cxlmd))
755 		return PTR_ERR(cxlmd);
756 
757 	rc = cxl_event_config(host_bridge, mds);
758 	if (rc)
759 		return rc;
760 
761 	rc = cxl_pci_ras_unmask(pdev);
762 	if (rc)
763 		dev_dbg(&pdev->dev, "No RAS reporting unmasked\n");
764 
765 	pci_save_state(pdev);
766 
767 	return rc;
768 }
769 
770 static const struct pci_device_id cxl_mem_pci_tbl[] = {
771 	/* PCI class code for CXL.mem Type-3 Devices */
772 	{ PCI_DEVICE_CLASS((PCI_CLASS_MEMORY_CXL << 8 | CXL_MEMORY_PROGIF), ~0)},
773 	{ /* terminate list */ },
774 };
775 MODULE_DEVICE_TABLE(pci, cxl_mem_pci_tbl);
776 
777 static pci_ers_result_t cxl_slot_reset(struct pci_dev *pdev)
778 {
779 	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
780 	struct cxl_memdev *cxlmd = cxlds->cxlmd;
781 	struct device *dev = &cxlmd->dev;
782 
783 	dev_info(&pdev->dev, "%s: restart CXL.mem after slot reset\n",
784 		 dev_name(dev));
785 	pci_restore_state(pdev);
786 	if (device_attach(dev) <= 0)
787 		return PCI_ERS_RESULT_DISCONNECT;
788 	return PCI_ERS_RESULT_RECOVERED;
789 }
790 
791 static void cxl_error_resume(struct pci_dev *pdev)
792 {
793 	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
794 	struct cxl_memdev *cxlmd = cxlds->cxlmd;
795 	struct device *dev = &cxlmd->dev;
796 
797 	dev_info(&pdev->dev, "%s: error resume %s\n", dev_name(dev),
798 		 dev->driver ? "successful" : "failed");
799 }
800 
801 static const struct pci_error_handlers cxl_error_handlers = {
802 	.error_detected	= cxl_error_detected,
803 	.slot_reset	= cxl_slot_reset,
804 	.resume		= cxl_error_resume,
805 	.cor_error_detected	= cxl_cor_error_detected,
806 };
807 
808 static struct pci_driver cxl_pci_driver = {
809 	.name			= KBUILD_MODNAME,
810 	.id_table		= cxl_mem_pci_tbl,
811 	.probe			= cxl_pci_probe,
812 	.err_handler		= &cxl_error_handlers,
813 	.driver	= {
814 		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
815 	},
816 };
817 
818 MODULE_LICENSE("GPL v2");
819 module_pci_driver(cxl_pci_driver);
820 MODULE_IMPORT_NS(CXL);
821