xref: /kernel/linux/linux-6.6/drivers/cxl/pci.c (revision 62306a36)
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#include "pmu.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 */
51static unsigned short mbox_ready_timeout = 60;
52module_param(mbox_ready_timeout, ushort, 0644);
53MODULE_PARM_DESC(mbox_ready_timeout, "seconds to wait for mailbox ready");
54
55static 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
88struct cxl_dev_id {
89	struct cxl_dev_state *cxlds;
90};
91
92static int cxl_request_irq(struct cxl_dev_state *cxlds, int irq,
93			   irq_handler_t handler, irq_handler_t thread_fn)
94{
95	struct device *dev = cxlds->dev;
96	struct cxl_dev_id *dev_id;
97
98	/* dev_id must be globally unique and must contain the cxlds */
99	dev_id = devm_kzalloc(dev, sizeof(*dev_id), GFP_KERNEL);
100	if (!dev_id)
101		return -ENOMEM;
102	dev_id->cxlds = cxlds;
103
104	return devm_request_threaded_irq(dev, irq, handler, thread_fn,
105					 IRQF_SHARED | IRQF_ONESHOT,
106					 NULL, dev_id);
107}
108
109static bool cxl_mbox_background_complete(struct cxl_dev_state *cxlds)
110{
111	u64 reg;
112
113	reg = readq(cxlds->regs.mbox + CXLDEV_MBOX_BG_CMD_STATUS_OFFSET);
114	return FIELD_GET(CXLDEV_MBOX_BG_CMD_COMMAND_PCT_MASK, reg) == 100;
115}
116
117static irqreturn_t cxl_pci_mbox_irq(int irq, void *id)
118{
119	u64 reg;
120	u16 opcode;
121	struct cxl_dev_id *dev_id = id;
122	struct cxl_dev_state *cxlds = dev_id->cxlds;
123	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds);
124
125	if (!cxl_mbox_background_complete(cxlds))
126		return IRQ_NONE;
127
128	reg = readq(cxlds->regs.mbox + CXLDEV_MBOX_BG_CMD_STATUS_OFFSET);
129	opcode = FIELD_GET(CXLDEV_MBOX_BG_CMD_COMMAND_OPCODE_MASK, reg);
130	if (opcode == CXL_MBOX_OP_SANITIZE) {
131		mutex_lock(&mds->mbox_mutex);
132		if (mds->security.sanitize_node)
133			mod_delayed_work(system_wq, &mds->security.poll_dwork, 0);
134		mutex_unlock(&mds->mbox_mutex);
135	} else {
136		/* short-circuit the wait in __cxl_pci_mbox_send_cmd() */
137		rcuwait_wake_up(&mds->mbox_wait);
138	}
139
140	return IRQ_HANDLED;
141}
142
143/*
144 * Sanitization operation polling mode.
145 */
146static void cxl_mbox_sanitize_work(struct work_struct *work)
147{
148	struct cxl_memdev_state *mds =
149		container_of(work, typeof(*mds), security.poll_dwork.work);
150	struct cxl_dev_state *cxlds = &mds->cxlds;
151
152	mutex_lock(&mds->mbox_mutex);
153	if (cxl_mbox_background_complete(cxlds)) {
154		mds->security.poll_tmo_secs = 0;
155		if (mds->security.sanitize_node)
156			sysfs_notify_dirent(mds->security.sanitize_node);
157		mds->security.sanitize_active = false;
158
159		dev_dbg(cxlds->dev, "Sanitization operation ended\n");
160	} else {
161		int timeout = mds->security.poll_tmo_secs + 10;
162
163		mds->security.poll_tmo_secs = min(15 * 60, timeout);
164		schedule_delayed_work(&mds->security.poll_dwork, timeout * HZ);
165	}
166	mutex_unlock(&mds->mbox_mutex);
167}
168
169/**
170 * __cxl_pci_mbox_send_cmd() - Execute a mailbox command
171 * @mds: The memory device driver data
172 * @mbox_cmd: Command to send to the memory device.
173 *
174 * Context: Any context. Expects mbox_mutex to be held.
175 * Return: -ETIMEDOUT if timeout occurred waiting for completion. 0 on success.
176 *         Caller should check the return code in @mbox_cmd to make sure it
177 *         succeeded.
178 *
179 * This is a generic form of the CXL mailbox send command thus only using the
180 * registers defined by the mailbox capability ID - CXL 2.0 8.2.8.4. Memory
181 * devices, and perhaps other types of CXL devices may have further information
182 * available upon error conditions. Driver facilities wishing to send mailbox
183 * commands should use the wrapper command.
184 *
185 * The CXL spec allows for up to two mailboxes. The intention is for the primary
186 * mailbox to be OS controlled and the secondary mailbox to be used by system
187 * firmware. This allows the OS and firmware to communicate with the device and
188 * not need to coordinate with each other. The driver only uses the primary
189 * mailbox.
190 */
191static int __cxl_pci_mbox_send_cmd(struct cxl_memdev_state *mds,
192				   struct cxl_mbox_cmd *mbox_cmd)
193{
194	struct cxl_dev_state *cxlds = &mds->cxlds;
195	void __iomem *payload = cxlds->regs.mbox + CXLDEV_MBOX_PAYLOAD_OFFSET;
196	struct device *dev = cxlds->dev;
197	u64 cmd_reg, status_reg;
198	size_t out_len;
199	int rc;
200
201	lockdep_assert_held(&mds->mbox_mutex);
202
203	/*
204	 * Here are the steps from 8.2.8.4 of the CXL 2.0 spec.
205	 *   1. Caller reads MB Control Register to verify doorbell is clear
206	 *   2. Caller writes Command Register
207	 *   3. Caller writes Command Payload Registers if input payload is non-empty
208	 *   4. Caller writes MB Control Register to set doorbell
209	 *   5. Caller either polls for doorbell to be clear or waits for interrupt if configured
210	 *   6. Caller reads MB Status Register to fetch Return code
211	 *   7. If command successful, Caller reads Command Register to get Payload Length
212	 *   8. If output payload is non-empty, host reads Command Payload Registers
213	 *
214	 * Hardware is free to do whatever it wants before the doorbell is rung,
215	 * and isn't allowed to change anything after it clears the doorbell. As
216	 * such, steps 2 and 3 can happen in any order, and steps 6, 7, 8 can
217	 * also happen in any order (though some orders might not make sense).
218	 */
219
220	/* #1 */
221	if (cxl_doorbell_busy(cxlds)) {
222		u64 md_status =
223			readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
224
225		cxl_cmd_err(cxlds->dev, mbox_cmd, md_status,
226			    "mailbox queue busy");
227		return -EBUSY;
228	}
229
230	/*
231	 * With sanitize polling, hardware might be done and the poller still
232	 * not be in sync. Ensure no new command comes in until so. Keep the
233	 * hardware semantics and only allow device health status.
234	 */
235	if (mds->security.poll_tmo_secs > 0) {
236		if (mbox_cmd->opcode != CXL_MBOX_OP_GET_HEALTH_INFO)
237			return -EBUSY;
238	}
239
240	cmd_reg = FIELD_PREP(CXLDEV_MBOX_CMD_COMMAND_OPCODE_MASK,
241			     mbox_cmd->opcode);
242	if (mbox_cmd->size_in) {
243		if (WARN_ON(!mbox_cmd->payload_in))
244			return -EINVAL;
245
246		cmd_reg |= FIELD_PREP(CXLDEV_MBOX_CMD_PAYLOAD_LENGTH_MASK,
247				      mbox_cmd->size_in);
248		memcpy_toio(payload, mbox_cmd->payload_in, mbox_cmd->size_in);
249	}
250
251	/* #2, #3 */
252	writeq(cmd_reg, cxlds->regs.mbox + CXLDEV_MBOX_CMD_OFFSET);
253
254	/* #4 */
255	dev_dbg(dev, "Sending command: 0x%04x\n", mbox_cmd->opcode);
256	writel(CXLDEV_MBOX_CTRL_DOORBELL,
257	       cxlds->regs.mbox + CXLDEV_MBOX_CTRL_OFFSET);
258
259	/* #5 */
260	rc = cxl_pci_mbox_wait_for_doorbell(cxlds);
261	if (rc == -ETIMEDOUT) {
262		u64 md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
263
264		cxl_cmd_err(cxlds->dev, mbox_cmd, md_status, "mailbox timeout");
265		return rc;
266	}
267
268	/* #6 */
269	status_reg = readq(cxlds->regs.mbox + CXLDEV_MBOX_STATUS_OFFSET);
270	mbox_cmd->return_code =
271		FIELD_GET(CXLDEV_MBOX_STATUS_RET_CODE_MASK, status_reg);
272
273	/*
274	 * Handle the background command in a synchronous manner.
275	 *
276	 * All other mailbox commands will serialize/queue on the mbox_mutex,
277	 * which we currently hold. Furthermore this also guarantees that
278	 * cxl_mbox_background_complete() checks are safe amongst each other,
279	 * in that no new bg operation can occur in between.
280	 *
281	 * Background operations are timesliced in accordance with the nature
282	 * of the command. In the event of timeout, the mailbox state is
283	 * indeterminate until the next successful command submission and the
284	 * driver can get back in sync with the hardware state.
285	 */
286	if (mbox_cmd->return_code == CXL_MBOX_CMD_RC_BACKGROUND) {
287		u64 bg_status_reg;
288		int i, timeout;
289
290		/*
291		 * Sanitization is a special case which monopolizes the device
292		 * and cannot be timesliced. Handle asynchronously instead,
293		 * and allow userspace to poll(2) for completion.
294		 */
295		if (mbox_cmd->opcode == CXL_MBOX_OP_SANITIZE) {
296			if (mds->security.sanitize_active)
297				return -EBUSY;
298
299			/* give first timeout a second */
300			timeout = 1;
301			mds->security.poll_tmo_secs = timeout;
302			mds->security.sanitize_active = true;
303			schedule_delayed_work(&mds->security.poll_dwork,
304					      timeout * HZ);
305			dev_dbg(dev, "Sanitization operation started\n");
306			goto success;
307		}
308
309		dev_dbg(dev, "Mailbox background operation (0x%04x) started\n",
310			mbox_cmd->opcode);
311
312		timeout = mbox_cmd->poll_interval_ms;
313		for (i = 0; i < mbox_cmd->poll_count; i++) {
314			if (rcuwait_wait_event_timeout(&mds->mbox_wait,
315				       cxl_mbox_background_complete(cxlds),
316				       TASK_UNINTERRUPTIBLE,
317				       msecs_to_jiffies(timeout)) > 0)
318				break;
319		}
320
321		if (!cxl_mbox_background_complete(cxlds)) {
322			dev_err(dev, "timeout waiting for background (%d ms)\n",
323				timeout * mbox_cmd->poll_count);
324			return -ETIMEDOUT;
325		}
326
327		bg_status_reg = readq(cxlds->regs.mbox +
328				      CXLDEV_MBOX_BG_CMD_STATUS_OFFSET);
329		mbox_cmd->return_code =
330			FIELD_GET(CXLDEV_MBOX_BG_CMD_COMMAND_RC_MASK,
331				  bg_status_reg);
332		dev_dbg(dev,
333			"Mailbox background operation (0x%04x) completed\n",
334			mbox_cmd->opcode);
335	}
336
337	if (mbox_cmd->return_code != CXL_MBOX_CMD_RC_SUCCESS) {
338		dev_dbg(dev, "Mailbox operation had an error: %s\n",
339			cxl_mbox_cmd_rc2str(mbox_cmd));
340		return 0; /* completed but caller must check return_code */
341	}
342
343success:
344	/* #7 */
345	cmd_reg = readq(cxlds->regs.mbox + CXLDEV_MBOX_CMD_OFFSET);
346	out_len = FIELD_GET(CXLDEV_MBOX_CMD_PAYLOAD_LENGTH_MASK, cmd_reg);
347
348	/* #8 */
349	if (out_len && mbox_cmd->payload_out) {
350		/*
351		 * Sanitize the copy. If hardware misbehaves, out_len per the
352		 * spec can actually be greater than the max allowed size (21
353		 * bits available but spec defined 1M max). The caller also may
354		 * have requested less data than the hardware supplied even
355		 * within spec.
356		 */
357		size_t n;
358
359		n = min3(mbox_cmd->size_out, mds->payload_size, out_len);
360		memcpy_fromio(mbox_cmd->payload_out, payload, n);
361		mbox_cmd->size_out = n;
362	} else {
363		mbox_cmd->size_out = 0;
364	}
365
366	return 0;
367}
368
369static int cxl_pci_mbox_send(struct cxl_memdev_state *mds,
370			     struct cxl_mbox_cmd *cmd)
371{
372	int rc;
373
374	mutex_lock_io(&mds->mbox_mutex);
375	rc = __cxl_pci_mbox_send_cmd(mds, cmd);
376	mutex_unlock(&mds->mbox_mutex);
377
378	return rc;
379}
380
381static int cxl_pci_setup_mailbox(struct cxl_memdev_state *mds)
382{
383	struct cxl_dev_state *cxlds = &mds->cxlds;
384	const int cap = readl(cxlds->regs.mbox + CXLDEV_MBOX_CAPS_OFFSET);
385	struct device *dev = cxlds->dev;
386	unsigned long timeout;
387	int irq, msgnum;
388	u64 md_status;
389	u32 ctrl;
390
391	timeout = jiffies + mbox_ready_timeout * HZ;
392	do {
393		md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
394		if (md_status & CXLMDEV_MBOX_IF_READY)
395			break;
396		if (msleep_interruptible(100))
397			break;
398	} while (!time_after(jiffies, timeout));
399
400	if (!(md_status & CXLMDEV_MBOX_IF_READY)) {
401		cxl_err(dev, md_status, "timeout awaiting mailbox ready");
402		return -ETIMEDOUT;
403	}
404
405	/*
406	 * A command may be in flight from a previous driver instance,
407	 * think kexec, do one doorbell wait so that
408	 * __cxl_pci_mbox_send_cmd() can assume that it is the only
409	 * source for future doorbell busy events.
410	 */
411	if (cxl_pci_mbox_wait_for_doorbell(cxlds) != 0) {
412		cxl_err(dev, md_status, "timeout awaiting mailbox idle");
413		return -ETIMEDOUT;
414	}
415
416	mds->mbox_send = cxl_pci_mbox_send;
417	mds->payload_size =
418		1 << FIELD_GET(CXLDEV_MBOX_CAP_PAYLOAD_SIZE_MASK, cap);
419
420	/*
421	 * CXL 2.0 8.2.8.4.3 Mailbox Capabilities Register
422	 *
423	 * If the size is too small, mandatory commands will not work and so
424	 * there's no point in going forward. If the size is too large, there's
425	 * no harm is soft limiting it.
426	 */
427	mds->payload_size = min_t(size_t, mds->payload_size, SZ_1M);
428	if (mds->payload_size < 256) {
429		dev_err(dev, "Mailbox is too small (%zub)",
430			mds->payload_size);
431		return -ENXIO;
432	}
433
434	dev_dbg(dev, "Mailbox payload sized %zu", mds->payload_size);
435
436	rcuwait_init(&mds->mbox_wait);
437	INIT_DELAYED_WORK(&mds->security.poll_dwork, cxl_mbox_sanitize_work);
438
439	/* background command interrupts are optional */
440	if (!(cap & CXLDEV_MBOX_CAP_BG_CMD_IRQ))
441		return 0;
442
443	msgnum = FIELD_GET(CXLDEV_MBOX_CAP_IRQ_MSGNUM_MASK, cap);
444	irq = pci_irq_vector(to_pci_dev(cxlds->dev), msgnum);
445	if (irq < 0)
446		return 0;
447
448	if (cxl_request_irq(cxlds, irq, NULL, cxl_pci_mbox_irq))
449		return 0;
450
451	dev_dbg(cxlds->dev, "Mailbox interrupts enabled\n");
452	/* enable background command mbox irq support */
453	ctrl = readl(cxlds->regs.mbox + CXLDEV_MBOX_CTRL_OFFSET);
454	ctrl |= CXLDEV_MBOX_CTRL_BG_CMD_IRQ;
455	writel(ctrl, cxlds->regs.mbox + CXLDEV_MBOX_CTRL_OFFSET);
456
457	return 0;
458}
459
460/*
461 * Assume that any RCIEP that emits the CXL memory expander class code
462 * is an RCD
463 */
464static bool is_cxl_restricted(struct pci_dev *pdev)
465{
466	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
467}
468
469static int cxl_rcrb_get_comp_regs(struct pci_dev *pdev,
470				  struct cxl_register_map *map)
471{
472	struct cxl_port *port;
473	struct cxl_dport *dport;
474	resource_size_t component_reg_phys;
475
476	*map = (struct cxl_register_map) {
477		.host = &pdev->dev,
478		.resource = CXL_RESOURCE_NONE,
479	};
480
481	port = cxl_pci_find_port(pdev, &dport);
482	if (!port)
483		return -EPROBE_DEFER;
484
485	component_reg_phys = cxl_rcd_component_reg_phys(&pdev->dev, dport);
486
487	put_device(&port->dev);
488
489	if (component_reg_phys == CXL_RESOURCE_NONE)
490		return -ENXIO;
491
492	map->resource = component_reg_phys;
493	map->reg_type = CXL_REGLOC_RBI_COMPONENT;
494	map->max_size = CXL_COMPONENT_REG_BLOCK_SIZE;
495
496	return 0;
497}
498
499static int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
500			      struct cxl_register_map *map)
501{
502	int rc;
503
504	rc = cxl_find_regblock(pdev, type, map);
505
506	/*
507	 * If the Register Locator DVSEC does not exist, check if it
508	 * is an RCH and try to extract the Component Registers from
509	 * an RCRB.
510	 */
511	if (rc && type == CXL_REGLOC_RBI_COMPONENT && is_cxl_restricted(pdev))
512		rc = cxl_rcrb_get_comp_regs(pdev, map);
513
514	if (rc)
515		return rc;
516
517	return cxl_setup_regs(map);
518}
519
520static int cxl_pci_ras_unmask(struct pci_dev *pdev)
521{
522	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
523	void __iomem *addr;
524	u32 orig_val, val, mask;
525	u16 cap;
526	int rc;
527
528	if (!cxlds->regs.ras) {
529		dev_dbg(&pdev->dev, "No RAS registers.\n");
530		return 0;
531	}
532
533	/* BIOS has PCIe AER error control */
534	if (!pcie_aer_is_native(pdev))
535		return 0;
536
537	rc = pcie_capability_read_word(pdev, PCI_EXP_DEVCTL, &cap);
538	if (rc)
539		return rc;
540
541	if (cap & PCI_EXP_DEVCTL_URRE) {
542		addr = cxlds->regs.ras + CXL_RAS_UNCORRECTABLE_MASK_OFFSET;
543		orig_val = readl(addr);
544
545		mask = CXL_RAS_UNCORRECTABLE_MASK_MASK |
546		       CXL_RAS_UNCORRECTABLE_MASK_F256B_MASK;
547		val = orig_val & ~mask;
548		writel(val, addr);
549		dev_dbg(&pdev->dev,
550			"Uncorrectable RAS Errors Mask: %#x -> %#x\n",
551			orig_val, val);
552	}
553
554	if (cap & PCI_EXP_DEVCTL_CERE) {
555		addr = cxlds->regs.ras + CXL_RAS_CORRECTABLE_MASK_OFFSET;
556		orig_val = readl(addr);
557		val = orig_val & ~CXL_RAS_CORRECTABLE_MASK_MASK;
558		writel(val, addr);
559		dev_dbg(&pdev->dev, "Correctable RAS Errors Mask: %#x -> %#x\n",
560			orig_val, val);
561	}
562
563	return 0;
564}
565
566static void free_event_buf(void *buf)
567{
568	kvfree(buf);
569}
570
571/*
572 * There is a single buffer for reading event logs from the mailbox.  All logs
573 * share this buffer protected by the mds->event_log_lock.
574 */
575static int cxl_mem_alloc_event_buf(struct cxl_memdev_state *mds)
576{
577	struct cxl_get_event_payload *buf;
578
579	buf = kvmalloc(mds->payload_size, GFP_KERNEL);
580	if (!buf)
581		return -ENOMEM;
582	mds->event.buf = buf;
583
584	return devm_add_action_or_reset(mds->cxlds.dev, free_event_buf, buf);
585}
586
587static int cxl_alloc_irq_vectors(struct pci_dev *pdev)
588{
589	int nvecs;
590
591	/*
592	 * Per CXL 3.0 3.1.1 CXL.io Endpoint a function on a CXL device must
593	 * not generate INTx messages if that function participates in
594	 * CXL.cache or CXL.mem.
595	 *
596	 * Additionally pci_alloc_irq_vectors() handles calling
597	 * pci_free_irq_vectors() automatically despite not being called
598	 * pcim_*.  See pci_setup_msi_context().
599	 */
600	nvecs = pci_alloc_irq_vectors(pdev, 1, CXL_PCI_DEFAULT_MAX_VECTORS,
601				      PCI_IRQ_MSIX | PCI_IRQ_MSI);
602	if (nvecs < 1) {
603		dev_dbg(&pdev->dev, "Failed to alloc irq vectors: %d\n", nvecs);
604		return -ENXIO;
605	}
606	return 0;
607}
608
609static irqreturn_t cxl_event_thread(int irq, void *id)
610{
611	struct cxl_dev_id *dev_id = id;
612	struct cxl_dev_state *cxlds = dev_id->cxlds;
613	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds);
614	u32 status;
615
616	do {
617		/*
618		 * CXL 3.0 8.2.8.3.1: The lower 32 bits are the status;
619		 * ignore the reserved upper 32 bits
620		 */
621		status = readl(cxlds->regs.status + CXLDEV_DEV_EVENT_STATUS_OFFSET);
622		/* Ignore logs unknown to the driver */
623		status &= CXLDEV_EVENT_STATUS_ALL;
624		if (!status)
625			break;
626		cxl_mem_get_event_records(mds, status);
627		cond_resched();
628	} while (status);
629
630	return IRQ_HANDLED;
631}
632
633static int cxl_event_req_irq(struct cxl_dev_state *cxlds, u8 setting)
634{
635	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
636	int irq;
637
638	if (FIELD_GET(CXLDEV_EVENT_INT_MODE_MASK, setting) != CXL_INT_MSI_MSIX)
639		return -ENXIO;
640
641	irq =  pci_irq_vector(pdev,
642			      FIELD_GET(CXLDEV_EVENT_INT_MSGNUM_MASK, setting));
643	if (irq < 0)
644		return irq;
645
646	return cxl_request_irq(cxlds, irq, NULL, cxl_event_thread);
647}
648
649static int cxl_event_get_int_policy(struct cxl_memdev_state *mds,
650				    struct cxl_event_interrupt_policy *policy)
651{
652	struct cxl_mbox_cmd mbox_cmd = {
653		.opcode = CXL_MBOX_OP_GET_EVT_INT_POLICY,
654		.payload_out = policy,
655		.size_out = sizeof(*policy),
656	};
657	int rc;
658
659	rc = cxl_internal_send_cmd(mds, &mbox_cmd);
660	if (rc < 0)
661		dev_err(mds->cxlds.dev,
662			"Failed to get event interrupt policy : %d", rc);
663
664	return rc;
665}
666
667static int cxl_event_config_msgnums(struct cxl_memdev_state *mds,
668				    struct cxl_event_interrupt_policy *policy)
669{
670	struct cxl_mbox_cmd mbox_cmd;
671	int rc;
672
673	*policy = (struct cxl_event_interrupt_policy) {
674		.info_settings = CXL_INT_MSI_MSIX,
675		.warn_settings = CXL_INT_MSI_MSIX,
676		.failure_settings = CXL_INT_MSI_MSIX,
677		.fatal_settings = CXL_INT_MSI_MSIX,
678	};
679
680	mbox_cmd = (struct cxl_mbox_cmd) {
681		.opcode = CXL_MBOX_OP_SET_EVT_INT_POLICY,
682		.payload_in = policy,
683		.size_in = sizeof(*policy),
684	};
685
686	rc = cxl_internal_send_cmd(mds, &mbox_cmd);
687	if (rc < 0) {
688		dev_err(mds->cxlds.dev, "Failed to set event interrupt policy : %d",
689			rc);
690		return rc;
691	}
692
693	/* Retrieve final interrupt settings */
694	return cxl_event_get_int_policy(mds, policy);
695}
696
697static int cxl_event_irqsetup(struct cxl_memdev_state *mds)
698{
699	struct cxl_dev_state *cxlds = &mds->cxlds;
700	struct cxl_event_interrupt_policy policy;
701	int rc;
702
703	rc = cxl_event_config_msgnums(mds, &policy);
704	if (rc)
705		return rc;
706
707	rc = cxl_event_req_irq(cxlds, policy.info_settings);
708	if (rc) {
709		dev_err(cxlds->dev, "Failed to get interrupt for event Info log\n");
710		return rc;
711	}
712
713	rc = cxl_event_req_irq(cxlds, policy.warn_settings);
714	if (rc) {
715		dev_err(cxlds->dev, "Failed to get interrupt for event Warn log\n");
716		return rc;
717	}
718
719	rc = cxl_event_req_irq(cxlds, policy.failure_settings);
720	if (rc) {
721		dev_err(cxlds->dev, "Failed to get interrupt for event Failure log\n");
722		return rc;
723	}
724
725	rc = cxl_event_req_irq(cxlds, policy.fatal_settings);
726	if (rc) {
727		dev_err(cxlds->dev, "Failed to get interrupt for event Fatal log\n");
728		return rc;
729	}
730
731	return 0;
732}
733
734static bool cxl_event_int_is_fw(u8 setting)
735{
736	u8 mode = FIELD_GET(CXLDEV_EVENT_INT_MODE_MASK, setting);
737
738	return mode == CXL_INT_FW;
739}
740
741static int cxl_event_config(struct pci_host_bridge *host_bridge,
742			    struct cxl_memdev_state *mds)
743{
744	struct cxl_event_interrupt_policy policy;
745	int rc;
746
747	/*
748	 * When BIOS maintains CXL error reporting control, it will process
749	 * event records.  Only one agent can do so.
750	 */
751	if (!host_bridge->native_cxl_error)
752		return 0;
753
754	rc = cxl_mem_alloc_event_buf(mds);
755	if (rc)
756		return rc;
757
758	rc = cxl_event_get_int_policy(mds, &policy);
759	if (rc)
760		return rc;
761
762	if (cxl_event_int_is_fw(policy.info_settings) ||
763	    cxl_event_int_is_fw(policy.warn_settings) ||
764	    cxl_event_int_is_fw(policy.failure_settings) ||
765	    cxl_event_int_is_fw(policy.fatal_settings)) {
766		dev_err(mds->cxlds.dev,
767			"FW still in control of Event Logs despite _OSC settings\n");
768		return -EBUSY;
769	}
770
771	rc = cxl_event_irqsetup(mds);
772	if (rc)
773		return rc;
774
775	cxl_mem_get_event_records(mds, CXLDEV_EVENT_STATUS_ALL);
776
777	return 0;
778}
779
780static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
781{
782	struct pci_host_bridge *host_bridge = pci_find_host_bridge(pdev->bus);
783	struct cxl_memdev_state *mds;
784	struct cxl_dev_state *cxlds;
785	struct cxl_register_map map;
786	struct cxl_memdev *cxlmd;
787	int i, rc, pmu_count;
788
789	/*
790	 * Double check the anonymous union trickery in struct cxl_regs
791	 * FIXME switch to struct_group()
792	 */
793	BUILD_BUG_ON(offsetof(struct cxl_regs, memdev) !=
794		     offsetof(struct cxl_regs, device_regs.memdev));
795
796	rc = pcim_enable_device(pdev);
797	if (rc)
798		return rc;
799	pci_set_master(pdev);
800
801	mds = cxl_memdev_state_create(&pdev->dev);
802	if (IS_ERR(mds))
803		return PTR_ERR(mds);
804	cxlds = &mds->cxlds;
805	pci_set_drvdata(pdev, cxlds);
806
807	cxlds->rcd = is_cxl_restricted(pdev);
808	cxlds->serial = pci_get_dsn(pdev);
809	cxlds->cxl_dvsec = pci_find_dvsec_capability(
810		pdev, PCI_DVSEC_VENDOR_ID_CXL, CXL_DVSEC_PCIE_DEVICE);
811	if (!cxlds->cxl_dvsec)
812		dev_warn(&pdev->dev,
813			 "Device DVSEC not present, skip CXL.mem init\n");
814
815	rc = cxl_pci_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map);
816	if (rc)
817		return rc;
818
819	rc = cxl_map_device_regs(&map, &cxlds->regs.device_regs);
820	if (rc)
821		return rc;
822
823	/*
824	 * If the component registers can't be found, the cxl_pci driver may
825	 * still be useful for management functions so don't return an error.
826	 */
827	cxlds->component_reg_phys = CXL_RESOURCE_NONE;
828	rc = cxl_pci_setup_regs(pdev, CXL_REGLOC_RBI_COMPONENT, &map);
829	if (rc)
830		dev_warn(&pdev->dev, "No component registers (%d)\n", rc);
831	else if (!map.component_map.ras.valid)
832		dev_dbg(&pdev->dev, "RAS registers not found\n");
833
834	cxlds->component_reg_phys = map.resource;
835
836	rc = cxl_map_component_regs(&map, &cxlds->regs.component,
837				    BIT(CXL_CM_CAP_CAP_ID_RAS));
838	if (rc)
839		dev_dbg(&pdev->dev, "Failed to map RAS capability.\n");
840
841	rc = cxl_await_media_ready(cxlds);
842	if (rc == 0)
843		cxlds->media_ready = true;
844	else
845		dev_warn(&pdev->dev, "Media not active (%d)\n", rc);
846
847	rc = cxl_alloc_irq_vectors(pdev);
848	if (rc)
849		return rc;
850
851	rc = cxl_pci_setup_mailbox(mds);
852	if (rc)
853		return rc;
854
855	rc = cxl_enumerate_cmds(mds);
856	if (rc)
857		return rc;
858
859	rc = cxl_set_timestamp(mds);
860	if (rc)
861		return rc;
862
863	rc = cxl_poison_state_init(mds);
864	if (rc)
865		return rc;
866
867	rc = cxl_dev_state_identify(mds);
868	if (rc)
869		return rc;
870
871	rc = cxl_mem_create_range_info(mds);
872	if (rc)
873		return rc;
874
875	cxlmd = devm_cxl_add_memdev(&pdev->dev, cxlds);
876	if (IS_ERR(cxlmd))
877		return PTR_ERR(cxlmd);
878
879	rc = devm_cxl_setup_fw_upload(&pdev->dev, mds);
880	if (rc)
881		return rc;
882
883	rc = devm_cxl_sanitize_setup_notifier(&pdev->dev, cxlmd);
884	if (rc)
885		return rc;
886
887	pmu_count = cxl_count_regblock(pdev, CXL_REGLOC_RBI_PMU);
888	for (i = 0; i < pmu_count; i++) {
889		struct cxl_pmu_regs pmu_regs;
890
891		rc = cxl_find_regblock_instance(pdev, CXL_REGLOC_RBI_PMU, &map, i);
892		if (rc) {
893			dev_dbg(&pdev->dev, "Could not find PMU regblock\n");
894			break;
895		}
896
897		rc = cxl_map_pmu_regs(pdev, &pmu_regs, &map);
898		if (rc) {
899			dev_dbg(&pdev->dev, "Could not map PMU regs\n");
900			break;
901		}
902
903		rc = devm_cxl_pmu_add(cxlds->dev, &pmu_regs, cxlmd->id, i, CXL_PMU_MEMDEV);
904		if (rc) {
905			dev_dbg(&pdev->dev, "Could not add PMU instance\n");
906			break;
907		}
908	}
909
910	rc = cxl_event_config(host_bridge, mds);
911	if (rc)
912		return rc;
913
914	rc = cxl_pci_ras_unmask(pdev);
915	if (rc)
916		dev_dbg(&pdev->dev, "No RAS reporting unmasked\n");
917
918	pci_save_state(pdev);
919
920	return rc;
921}
922
923static const struct pci_device_id cxl_mem_pci_tbl[] = {
924	/* PCI class code for CXL.mem Type-3 Devices */
925	{ PCI_DEVICE_CLASS((PCI_CLASS_MEMORY_CXL << 8 | CXL_MEMORY_PROGIF), ~0)},
926	{ /* terminate list */ },
927};
928MODULE_DEVICE_TABLE(pci, cxl_mem_pci_tbl);
929
930static pci_ers_result_t cxl_slot_reset(struct pci_dev *pdev)
931{
932	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
933	struct cxl_memdev *cxlmd = cxlds->cxlmd;
934	struct device *dev = &cxlmd->dev;
935
936	dev_info(&pdev->dev, "%s: restart CXL.mem after slot reset\n",
937		 dev_name(dev));
938	pci_restore_state(pdev);
939	if (device_attach(dev) <= 0)
940		return PCI_ERS_RESULT_DISCONNECT;
941	return PCI_ERS_RESULT_RECOVERED;
942}
943
944static void cxl_error_resume(struct pci_dev *pdev)
945{
946	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
947	struct cxl_memdev *cxlmd = cxlds->cxlmd;
948	struct device *dev = &cxlmd->dev;
949
950	dev_info(&pdev->dev, "%s: error resume %s\n", dev_name(dev),
951		 dev->driver ? "successful" : "failed");
952}
953
954static const struct pci_error_handlers cxl_error_handlers = {
955	.error_detected	= cxl_error_detected,
956	.slot_reset	= cxl_slot_reset,
957	.resume		= cxl_error_resume,
958	.cor_error_detected	= cxl_cor_error_detected,
959};
960
961static struct pci_driver cxl_pci_driver = {
962	.name			= KBUILD_MODNAME,
963	.id_table		= cxl_mem_pci_tbl,
964	.probe			= cxl_pci_probe,
965	.err_handler		= &cxl_error_handlers,
966	.driver	= {
967		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
968	},
969};
970
971MODULE_LICENSE("GPL v2");
972module_pci_driver(cxl_pci_driver);
973MODULE_IMPORT_NS(CXL);
974