1// SPDX-License-Identifier: GPL-2.0-only
2/* Copyright(c) 2020 Intel Corporation. All rights reserved. */
3#include <asm-generic/unaligned.h>
4#include <linux/io-64-nonatomic-lo-hi.h>
5#include <linux/moduleparam.h>
6#include <linux/module.h>
7#include <linux/delay.h>
8#include <linux/sizes.h>
9#include <linux/mutex.h>
10#include <linux/list.h>
11#include <linux/pci.h>
12#include <linux/aer.h>
13#include <linux/io.h>
14#include "cxlmem.h"
15#include "cxlpci.h"
16#include "cxl.h"
17#include "pmu.h"
18
19/**
20 * DOC: cxl pci
21 *
22 * This implements the PCI exclusive functionality for a CXL device as it is
23 * defined by the Compute Express Link specification. CXL devices may surface
24 * certain functionality even if it isn't CXL enabled. While this driver is
25 * focused around the PCI specific aspects of a CXL device, it binds to the
26 * specific CXL memory device class code, and therefore the implementation of
27 * cxl_pci is focused around CXL memory devices.
28 *
29 * The driver has several responsibilities, mainly:
30 *  - Create the memX device and register on the CXL bus.
31 *  - Enumerate device's register interface and map them.
32 *  - Registers nvdimm bridge device with cxl_core.
33 *  - Registers a CXL mailbox with cxl_core.
34 */
35
36#define cxl_doorbell_busy(cxlds)                                                \
37	(readl((cxlds)->regs.mbox + CXLDEV_MBOX_CTRL_OFFSET) &                  \
38	 CXLDEV_MBOX_CTRL_DOORBELL)
39
40/* CXL 2.0 - 8.2.8.4 */
41#define CXL_MAILBOX_TIMEOUT_MS (2 * HZ)
42
43/*
44 * CXL 2.0 ECN "Add Mailbox Ready Time" defines a capability field to
45 * dictate how long to wait for the mailbox to become ready. The new
46 * field allows the device to tell software the amount of time to wait
47 * before mailbox ready. This field per the spec theoretically allows
48 * for up to 255 seconds. 255 seconds is unreasonably long, its longer
49 * than the maximum SATA port link recovery wait. Default to 60 seconds
50 * until someone builds a CXL device that needs more time in practice.
51 */
52static unsigned short mbox_ready_timeout = 60;
53module_param(mbox_ready_timeout, ushort, 0644);
54MODULE_PARM_DESC(mbox_ready_timeout, "seconds to wait for mailbox ready");
55
56static int cxl_pci_mbox_wait_for_doorbell(struct cxl_dev_state *cxlds)
57{
58	const unsigned long start = jiffies;
59	unsigned long end = start;
60
61	while (cxl_doorbell_busy(cxlds)) {
62		end = jiffies;
63
64		if (time_after(end, start + CXL_MAILBOX_TIMEOUT_MS)) {
65			/* Check again in case preempted before timeout test */
66			if (!cxl_doorbell_busy(cxlds))
67				break;
68			return -ETIMEDOUT;
69		}
70		cpu_relax();
71	}
72
73	dev_dbg(cxlds->dev, "Doorbell wait took %dms",
74		jiffies_to_msecs(end) - jiffies_to_msecs(start));
75	return 0;
76}
77
78#define cxl_err(dev, status, msg)                                        \
79	dev_err_ratelimited(dev, msg ", device state %s%s\n",                  \
80			    status & CXLMDEV_DEV_FATAL ? " fatal" : "",        \
81			    status & CXLMDEV_FW_HALT ? " firmware-halt" : "")
82
83#define cxl_cmd_err(dev, cmd, status, msg)                               \
84	dev_err_ratelimited(dev, msg " (opcode: %#x), device state %s%s\n",    \
85			    (cmd)->opcode,                                     \
86			    status & CXLMDEV_DEV_FATAL ? " fatal" : "",        \
87			    status & CXLMDEV_FW_HALT ? " firmware-halt" : "")
88
89/*
90 * Threaded irq dev_id's must be globally unique.  cxl_dev_id provides a unique
91 * wrapper object for each irq within the same cxlds.
92 */
93struct cxl_dev_id {
94	struct cxl_dev_state *cxlds;
95};
96
97static int cxl_request_irq(struct cxl_dev_state *cxlds, int irq,
98			   irq_handler_t thread_fn)
99{
100	struct device *dev = cxlds->dev;
101	struct cxl_dev_id *dev_id;
102
103	dev_id = devm_kzalloc(dev, sizeof(*dev_id), GFP_KERNEL);
104	if (!dev_id)
105		return -ENOMEM;
106	dev_id->cxlds = cxlds;
107
108	return devm_request_threaded_irq(dev, irq, NULL, thread_fn,
109					 IRQF_SHARED | IRQF_ONESHOT, NULL,
110					 dev_id);
111}
112
113static bool cxl_mbox_background_complete(struct cxl_dev_state *cxlds)
114{
115	u64 reg;
116
117	reg = readq(cxlds->regs.mbox + CXLDEV_MBOX_BG_CMD_STATUS_OFFSET);
118	return FIELD_GET(CXLDEV_MBOX_BG_CMD_COMMAND_PCT_MASK, reg) == 100;
119}
120
121static irqreturn_t cxl_pci_mbox_irq(int irq, void *id)
122{
123	u64 reg;
124	u16 opcode;
125	struct cxl_dev_id *dev_id = id;
126	struct cxl_dev_state *cxlds = dev_id->cxlds;
127	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds);
128
129	if (!cxl_mbox_background_complete(cxlds))
130		return IRQ_NONE;
131
132	reg = readq(cxlds->regs.mbox + CXLDEV_MBOX_BG_CMD_STATUS_OFFSET);
133	opcode = FIELD_GET(CXLDEV_MBOX_BG_CMD_COMMAND_OPCODE_MASK, reg);
134	if (opcode == CXL_MBOX_OP_SANITIZE) {
135		mutex_lock(&mds->mbox_mutex);
136		if (mds->security.sanitize_node)
137			mod_delayed_work(system_wq, &mds->security.poll_dwork, 0);
138		mutex_unlock(&mds->mbox_mutex);
139	} else {
140		/* short-circuit the wait in __cxl_pci_mbox_send_cmd() */
141		rcuwait_wake_up(&mds->mbox_wait);
142	}
143
144	return IRQ_HANDLED;
145}
146
147/*
148 * Sanitization operation polling mode.
149 */
150static void cxl_mbox_sanitize_work(struct work_struct *work)
151{
152	struct cxl_memdev_state *mds =
153		container_of(work, typeof(*mds), security.poll_dwork.work);
154	struct cxl_dev_state *cxlds = &mds->cxlds;
155
156	mutex_lock(&mds->mbox_mutex);
157	if (cxl_mbox_background_complete(cxlds)) {
158		mds->security.poll_tmo_secs = 0;
159		if (mds->security.sanitize_node)
160			sysfs_notify_dirent(mds->security.sanitize_node);
161		mds->security.sanitize_active = false;
162
163		dev_dbg(cxlds->dev, "Sanitization operation ended\n");
164	} else {
165		int timeout = mds->security.poll_tmo_secs + 10;
166
167		mds->security.poll_tmo_secs = min(15 * 60, timeout);
168		schedule_delayed_work(&mds->security.poll_dwork, timeout * HZ);
169	}
170	mutex_unlock(&mds->mbox_mutex);
171}
172
173/**
174 * __cxl_pci_mbox_send_cmd() - Execute a mailbox command
175 * @mds: The memory device driver data
176 * @mbox_cmd: Command to send to the memory device.
177 *
178 * Context: Any context. Expects mbox_mutex to be held.
179 * Return: -ETIMEDOUT if timeout occurred waiting for completion. 0 on success.
180 *         Caller should check the return code in @mbox_cmd to make sure it
181 *         succeeded.
182 *
183 * This is a generic form of the CXL mailbox send command thus only using the
184 * registers defined by the mailbox capability ID - CXL 2.0 8.2.8.4. Memory
185 * devices, and perhaps other types of CXL devices may have further information
186 * available upon error conditions. Driver facilities wishing to send mailbox
187 * commands should use the wrapper command.
188 *
189 * The CXL spec allows for up to two mailboxes. The intention is for the primary
190 * mailbox to be OS controlled and the secondary mailbox to be used by system
191 * firmware. This allows the OS and firmware to communicate with the device and
192 * not need to coordinate with each other. The driver only uses the primary
193 * mailbox.
194 */
195static int __cxl_pci_mbox_send_cmd(struct cxl_memdev_state *mds,
196				   struct cxl_mbox_cmd *mbox_cmd)
197{
198	struct cxl_dev_state *cxlds = &mds->cxlds;
199	void __iomem *payload = cxlds->regs.mbox + CXLDEV_MBOX_PAYLOAD_OFFSET;
200	struct device *dev = cxlds->dev;
201	u64 cmd_reg, status_reg;
202	size_t out_len;
203	int rc;
204
205	lockdep_assert_held(&mds->mbox_mutex);
206
207	/*
208	 * Here are the steps from 8.2.8.4 of the CXL 2.0 spec.
209	 *   1. Caller reads MB Control Register to verify doorbell is clear
210	 *   2. Caller writes Command Register
211	 *   3. Caller writes Command Payload Registers if input payload is non-empty
212	 *   4. Caller writes MB Control Register to set doorbell
213	 *   5. Caller either polls for doorbell to be clear or waits for interrupt if configured
214	 *   6. Caller reads MB Status Register to fetch Return code
215	 *   7. If command successful, Caller reads Command Register to get Payload Length
216	 *   8. If output payload is non-empty, host reads Command Payload Registers
217	 *
218	 * Hardware is free to do whatever it wants before the doorbell is rung,
219	 * and isn't allowed to change anything after it clears the doorbell. As
220	 * such, steps 2 and 3 can happen in any order, and steps 6, 7, 8 can
221	 * also happen in any order (though some orders might not make sense).
222	 */
223
224	/* #1 */
225	if (cxl_doorbell_busy(cxlds)) {
226		u64 md_status =
227			readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
228
229		cxl_cmd_err(cxlds->dev, mbox_cmd, md_status,
230			    "mailbox queue busy");
231		return -EBUSY;
232	}
233
234	/*
235	 * With sanitize polling, hardware might be done and the poller still
236	 * not be in sync. Ensure no new command comes in until so. Keep the
237	 * hardware semantics and only allow device health status.
238	 */
239	if (mds->security.poll_tmo_secs > 0) {
240		if (mbox_cmd->opcode != CXL_MBOX_OP_GET_HEALTH_INFO)
241			return -EBUSY;
242	}
243
244	cmd_reg = FIELD_PREP(CXLDEV_MBOX_CMD_COMMAND_OPCODE_MASK,
245			     mbox_cmd->opcode);
246	if (mbox_cmd->size_in) {
247		if (WARN_ON(!mbox_cmd->payload_in))
248			return -EINVAL;
249
250		cmd_reg |= FIELD_PREP(CXLDEV_MBOX_CMD_PAYLOAD_LENGTH_MASK,
251				      mbox_cmd->size_in);
252		memcpy_toio(payload, mbox_cmd->payload_in, mbox_cmd->size_in);
253	}
254
255	/* #2, #3 */
256	writeq(cmd_reg, cxlds->regs.mbox + CXLDEV_MBOX_CMD_OFFSET);
257
258	/* #4 */
259	dev_dbg(dev, "Sending command: 0x%04x\n", mbox_cmd->opcode);
260	writel(CXLDEV_MBOX_CTRL_DOORBELL,
261	       cxlds->regs.mbox + CXLDEV_MBOX_CTRL_OFFSET);
262
263	/* #5 */
264	rc = cxl_pci_mbox_wait_for_doorbell(cxlds);
265	if (rc == -ETIMEDOUT) {
266		u64 md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
267
268		cxl_cmd_err(cxlds->dev, mbox_cmd, md_status, "mailbox timeout");
269		return rc;
270	}
271
272	/* #6 */
273	status_reg = readq(cxlds->regs.mbox + CXLDEV_MBOX_STATUS_OFFSET);
274	mbox_cmd->return_code =
275		FIELD_GET(CXLDEV_MBOX_STATUS_RET_CODE_MASK, status_reg);
276
277	/*
278	 * Handle the background command in a synchronous manner.
279	 *
280	 * All other mailbox commands will serialize/queue on the mbox_mutex,
281	 * which we currently hold. Furthermore this also guarantees that
282	 * cxl_mbox_background_complete() checks are safe amongst each other,
283	 * in that no new bg operation can occur in between.
284	 *
285	 * Background operations are timesliced in accordance with the nature
286	 * of the command. In the event of timeout, the mailbox state is
287	 * indeterminate until the next successful command submission and the
288	 * driver can get back in sync with the hardware state.
289	 */
290	if (mbox_cmd->return_code == CXL_MBOX_CMD_RC_BACKGROUND) {
291		u64 bg_status_reg;
292		int i, timeout;
293
294		/*
295		 * Sanitization is a special case which monopolizes the device
296		 * and cannot be timesliced. Handle asynchronously instead,
297		 * and allow userspace to poll(2) for completion.
298		 */
299		if (mbox_cmd->opcode == CXL_MBOX_OP_SANITIZE) {
300			if (mds->security.sanitize_active)
301				return -EBUSY;
302
303			/* give first timeout a second */
304			timeout = 1;
305			mds->security.poll_tmo_secs = timeout;
306			mds->security.sanitize_active = true;
307			schedule_delayed_work(&mds->security.poll_dwork,
308					      timeout * HZ);
309			dev_dbg(dev, "Sanitization operation started\n");
310			goto success;
311		}
312
313		dev_dbg(dev, "Mailbox background operation (0x%04x) started\n",
314			mbox_cmd->opcode);
315
316		timeout = mbox_cmd->poll_interval_ms;
317		for (i = 0; i < mbox_cmd->poll_count; i++) {
318			if (rcuwait_wait_event_timeout(&mds->mbox_wait,
319				       cxl_mbox_background_complete(cxlds),
320				       TASK_UNINTERRUPTIBLE,
321				       msecs_to_jiffies(timeout)) > 0)
322				break;
323		}
324
325		if (!cxl_mbox_background_complete(cxlds)) {
326			dev_err(dev, "timeout waiting for background (%d ms)\n",
327				timeout * mbox_cmd->poll_count);
328			return -ETIMEDOUT;
329		}
330
331		bg_status_reg = readq(cxlds->regs.mbox +
332				      CXLDEV_MBOX_BG_CMD_STATUS_OFFSET);
333		mbox_cmd->return_code =
334			FIELD_GET(CXLDEV_MBOX_BG_CMD_COMMAND_RC_MASK,
335				  bg_status_reg);
336		dev_dbg(dev,
337			"Mailbox background operation (0x%04x) completed\n",
338			mbox_cmd->opcode);
339	}
340
341	if (mbox_cmd->return_code != CXL_MBOX_CMD_RC_SUCCESS) {
342		dev_dbg(dev, "Mailbox operation had an error: %s\n",
343			cxl_mbox_cmd_rc2str(mbox_cmd));
344		return 0; /* completed but caller must check return_code */
345	}
346
347success:
348	/* #7 */
349	cmd_reg = readq(cxlds->regs.mbox + CXLDEV_MBOX_CMD_OFFSET);
350	out_len = FIELD_GET(CXLDEV_MBOX_CMD_PAYLOAD_LENGTH_MASK, cmd_reg);
351
352	/* #8 */
353	if (out_len && mbox_cmd->payload_out) {
354		/*
355		 * Sanitize the copy. If hardware misbehaves, out_len per the
356		 * spec can actually be greater than the max allowed size (21
357		 * bits available but spec defined 1M max). The caller also may
358		 * have requested less data than the hardware supplied even
359		 * within spec.
360		 */
361		size_t n;
362
363		n = min3(mbox_cmd->size_out, mds->payload_size, out_len);
364		memcpy_fromio(mbox_cmd->payload_out, payload, n);
365		mbox_cmd->size_out = n;
366	} else {
367		mbox_cmd->size_out = 0;
368	}
369
370	return 0;
371}
372
373static int cxl_pci_mbox_send(struct cxl_memdev_state *mds,
374			     struct cxl_mbox_cmd *cmd)
375{
376	int rc;
377
378	mutex_lock_io(&mds->mbox_mutex);
379	rc = __cxl_pci_mbox_send_cmd(mds, cmd);
380	mutex_unlock(&mds->mbox_mutex);
381
382	return rc;
383}
384
385static int cxl_pci_setup_mailbox(struct cxl_memdev_state *mds, bool irq_avail)
386{
387	struct cxl_dev_state *cxlds = &mds->cxlds;
388	const int cap = readl(cxlds->regs.mbox + CXLDEV_MBOX_CAPS_OFFSET);
389	struct device *dev = cxlds->dev;
390	unsigned long timeout;
391	int irq, msgnum;
392	u64 md_status;
393	u32 ctrl;
394
395	timeout = jiffies + mbox_ready_timeout * HZ;
396	do {
397		md_status = readq(cxlds->regs.memdev + CXLMDEV_STATUS_OFFSET);
398		if (md_status & CXLMDEV_MBOX_IF_READY)
399			break;
400		if (msleep_interruptible(100))
401			break;
402	} while (!time_after(jiffies, timeout));
403
404	if (!(md_status & CXLMDEV_MBOX_IF_READY)) {
405		cxl_err(dev, md_status, "timeout awaiting mailbox ready");
406		return -ETIMEDOUT;
407	}
408
409	/*
410	 * A command may be in flight from a previous driver instance,
411	 * think kexec, do one doorbell wait so that
412	 * __cxl_pci_mbox_send_cmd() can assume that it is the only
413	 * source for future doorbell busy events.
414	 */
415	if (cxl_pci_mbox_wait_for_doorbell(cxlds) != 0) {
416		cxl_err(dev, md_status, "timeout awaiting mailbox idle");
417		return -ETIMEDOUT;
418	}
419
420	mds->mbox_send = cxl_pci_mbox_send;
421	mds->payload_size =
422		1 << FIELD_GET(CXLDEV_MBOX_CAP_PAYLOAD_SIZE_MASK, cap);
423
424	/*
425	 * CXL 2.0 8.2.8.4.3 Mailbox Capabilities Register
426	 *
427	 * If the size is too small, mandatory commands will not work and so
428	 * there's no point in going forward. If the size is too large, there's
429	 * no harm is soft limiting it.
430	 */
431	mds->payload_size = min_t(size_t, mds->payload_size, SZ_1M);
432	if (mds->payload_size < 256) {
433		dev_err(dev, "Mailbox is too small (%zub)",
434			mds->payload_size);
435		return -ENXIO;
436	}
437
438	dev_dbg(dev, "Mailbox payload sized %zu", mds->payload_size);
439
440	rcuwait_init(&mds->mbox_wait);
441	INIT_DELAYED_WORK(&mds->security.poll_dwork, cxl_mbox_sanitize_work);
442
443	/* background command interrupts are optional */
444	if (!(cap & CXLDEV_MBOX_CAP_BG_CMD_IRQ) || !irq_avail)
445		return 0;
446
447	msgnum = FIELD_GET(CXLDEV_MBOX_CAP_IRQ_MSGNUM_MASK, cap);
448	irq = pci_irq_vector(to_pci_dev(cxlds->dev), msgnum);
449	if (irq < 0)
450		return 0;
451
452	if (cxl_request_irq(cxlds, irq, cxl_pci_mbox_irq))
453		return 0;
454
455	dev_dbg(cxlds->dev, "Mailbox interrupts enabled\n");
456	/* enable background command mbox irq support */
457	ctrl = readl(cxlds->regs.mbox + CXLDEV_MBOX_CTRL_OFFSET);
458	ctrl |= CXLDEV_MBOX_CTRL_BG_CMD_IRQ;
459	writel(ctrl, cxlds->regs.mbox + CXLDEV_MBOX_CTRL_OFFSET);
460
461	return 0;
462}
463
464/*
465 * Assume that any RCIEP that emits the CXL memory expander class code
466 * is an RCD
467 */
468static bool is_cxl_restricted(struct pci_dev *pdev)
469{
470	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
471}
472
473static int cxl_rcrb_get_comp_regs(struct pci_dev *pdev,
474				  struct cxl_register_map *map)
475{
476	struct cxl_port *port;
477	struct cxl_dport *dport;
478	resource_size_t component_reg_phys;
479
480	*map = (struct cxl_register_map) {
481		.host = &pdev->dev,
482		.resource = CXL_RESOURCE_NONE,
483	};
484
485	port = cxl_pci_find_port(pdev, &dport);
486	if (!port)
487		return -EPROBE_DEFER;
488
489	component_reg_phys = cxl_rcd_component_reg_phys(&pdev->dev, dport);
490
491	put_device(&port->dev);
492
493	if (component_reg_phys == CXL_RESOURCE_NONE)
494		return -ENXIO;
495
496	map->resource = component_reg_phys;
497	map->reg_type = CXL_REGLOC_RBI_COMPONENT;
498	map->max_size = CXL_COMPONENT_REG_BLOCK_SIZE;
499
500	return 0;
501}
502
503static int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
504			      struct cxl_register_map *map)
505{
506	int rc;
507
508	rc = cxl_find_regblock(pdev, type, map);
509
510	/*
511	 * If the Register Locator DVSEC does not exist, check if it
512	 * is an RCH and try to extract the Component Registers from
513	 * an RCRB.
514	 */
515	if (rc && type == CXL_REGLOC_RBI_COMPONENT && is_cxl_restricted(pdev))
516		rc = cxl_rcrb_get_comp_regs(pdev, map);
517
518	if (rc)
519		return rc;
520
521	return cxl_setup_regs(map);
522}
523
524static int cxl_pci_ras_unmask(struct pci_dev *pdev)
525{
526	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
527	void __iomem *addr;
528	u32 orig_val, val, mask;
529	u16 cap;
530	int rc;
531
532	if (!cxlds->regs.ras) {
533		dev_dbg(&pdev->dev, "No RAS registers.\n");
534		return 0;
535	}
536
537	/* BIOS has PCIe AER error control */
538	if (!pcie_aer_is_native(pdev))
539		return 0;
540
541	rc = pcie_capability_read_word(pdev, PCI_EXP_DEVCTL, &cap);
542	if (rc)
543		return rc;
544
545	if (cap & PCI_EXP_DEVCTL_URRE) {
546		addr = cxlds->regs.ras + CXL_RAS_UNCORRECTABLE_MASK_OFFSET;
547		orig_val = readl(addr);
548
549		mask = CXL_RAS_UNCORRECTABLE_MASK_MASK |
550		       CXL_RAS_UNCORRECTABLE_MASK_F256B_MASK;
551		val = orig_val & ~mask;
552		writel(val, addr);
553		dev_dbg(&pdev->dev,
554			"Uncorrectable RAS Errors Mask: %#x -> %#x\n",
555			orig_val, val);
556	}
557
558	if (cap & PCI_EXP_DEVCTL_CERE) {
559		addr = cxlds->regs.ras + CXL_RAS_CORRECTABLE_MASK_OFFSET;
560		orig_val = readl(addr);
561		val = orig_val & ~CXL_RAS_CORRECTABLE_MASK_MASK;
562		writel(val, addr);
563		dev_dbg(&pdev->dev, "Correctable RAS Errors Mask: %#x -> %#x\n",
564			orig_val, val);
565	}
566
567	return 0;
568}
569
570static void free_event_buf(void *buf)
571{
572	kvfree(buf);
573}
574
575/*
576 * There is a single buffer for reading event logs from the mailbox.  All logs
577 * share this buffer protected by the mds->event_log_lock.
578 */
579static int cxl_mem_alloc_event_buf(struct cxl_memdev_state *mds)
580{
581	struct cxl_get_event_payload *buf;
582
583	buf = kvmalloc(mds->payload_size, GFP_KERNEL);
584	if (!buf)
585		return -ENOMEM;
586	mds->event.buf = buf;
587
588	return devm_add_action_or_reset(mds->cxlds.dev, free_event_buf, buf);
589}
590
591static bool cxl_alloc_irq_vectors(struct pci_dev *pdev)
592{
593	int nvecs;
594
595	/*
596	 * Per CXL 3.0 3.1.1 CXL.io Endpoint a function on a CXL device must
597	 * not generate INTx messages if that function participates in
598	 * CXL.cache or CXL.mem.
599	 *
600	 * Additionally pci_alloc_irq_vectors() handles calling
601	 * pci_free_irq_vectors() automatically despite not being called
602	 * pcim_*.  See pci_setup_msi_context().
603	 */
604	nvecs = pci_alloc_irq_vectors(pdev, 1, CXL_PCI_DEFAULT_MAX_VECTORS,
605				      PCI_IRQ_MSIX | PCI_IRQ_MSI);
606	if (nvecs < 1) {
607		dev_dbg(&pdev->dev, "Failed to alloc irq vectors: %d\n", nvecs);
608		return false;
609	}
610	return true;
611}
612
613static irqreturn_t cxl_event_thread(int irq, void *id)
614{
615	struct cxl_dev_id *dev_id = id;
616	struct cxl_dev_state *cxlds = dev_id->cxlds;
617	struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds);
618	u32 status;
619
620	do {
621		/*
622		 * CXL 3.0 8.2.8.3.1: The lower 32 bits are the status;
623		 * ignore the reserved upper 32 bits
624		 */
625		status = readl(cxlds->regs.status + CXLDEV_DEV_EVENT_STATUS_OFFSET);
626		/* Ignore logs unknown to the driver */
627		status &= CXLDEV_EVENT_STATUS_ALL;
628		if (!status)
629			break;
630		cxl_mem_get_event_records(mds, status);
631		cond_resched();
632	} while (status);
633
634	return IRQ_HANDLED;
635}
636
637static int cxl_event_req_irq(struct cxl_dev_state *cxlds, u8 setting)
638{
639	struct pci_dev *pdev = to_pci_dev(cxlds->dev);
640	int irq;
641
642	if (FIELD_GET(CXLDEV_EVENT_INT_MODE_MASK, setting) != CXL_INT_MSI_MSIX)
643		return -ENXIO;
644
645	irq =  pci_irq_vector(pdev,
646			      FIELD_GET(CXLDEV_EVENT_INT_MSGNUM_MASK, setting));
647	if (irq < 0)
648		return irq;
649
650	return cxl_request_irq(cxlds, irq, cxl_event_thread);
651}
652
653static int cxl_event_get_int_policy(struct cxl_memdev_state *mds,
654				    struct cxl_event_interrupt_policy *policy)
655{
656	struct cxl_mbox_cmd mbox_cmd = {
657		.opcode = CXL_MBOX_OP_GET_EVT_INT_POLICY,
658		.payload_out = policy,
659		.size_out = sizeof(*policy),
660	};
661	int rc;
662
663	rc = cxl_internal_send_cmd(mds, &mbox_cmd);
664	if (rc < 0)
665		dev_err(mds->cxlds.dev,
666			"Failed to get event interrupt policy : %d", rc);
667
668	return rc;
669}
670
671static int cxl_event_config_msgnums(struct cxl_memdev_state *mds,
672				    struct cxl_event_interrupt_policy *policy)
673{
674	struct cxl_mbox_cmd mbox_cmd;
675	int rc;
676
677	*policy = (struct cxl_event_interrupt_policy) {
678		.info_settings = CXL_INT_MSI_MSIX,
679		.warn_settings = CXL_INT_MSI_MSIX,
680		.failure_settings = CXL_INT_MSI_MSIX,
681		.fatal_settings = CXL_INT_MSI_MSIX,
682	};
683
684	mbox_cmd = (struct cxl_mbox_cmd) {
685		.opcode = CXL_MBOX_OP_SET_EVT_INT_POLICY,
686		.payload_in = policy,
687		.size_in = sizeof(*policy),
688	};
689
690	rc = cxl_internal_send_cmd(mds, &mbox_cmd);
691	if (rc < 0) {
692		dev_err(mds->cxlds.dev, "Failed to set event interrupt policy : %d",
693			rc);
694		return rc;
695	}
696
697	/* Retrieve final interrupt settings */
698	return cxl_event_get_int_policy(mds, policy);
699}
700
701static int cxl_event_irqsetup(struct cxl_memdev_state *mds)
702{
703	struct cxl_dev_state *cxlds = &mds->cxlds;
704	struct cxl_event_interrupt_policy policy;
705	int rc;
706
707	rc = cxl_event_config_msgnums(mds, &policy);
708	if (rc)
709		return rc;
710
711	rc = cxl_event_req_irq(cxlds, policy.info_settings);
712	if (rc) {
713		dev_err(cxlds->dev, "Failed to get interrupt for event Info log\n");
714		return rc;
715	}
716
717	rc = cxl_event_req_irq(cxlds, policy.warn_settings);
718	if (rc) {
719		dev_err(cxlds->dev, "Failed to get interrupt for event Warn log\n");
720		return rc;
721	}
722
723	rc = cxl_event_req_irq(cxlds, policy.failure_settings);
724	if (rc) {
725		dev_err(cxlds->dev, "Failed to get interrupt for event Failure log\n");
726		return rc;
727	}
728
729	rc = cxl_event_req_irq(cxlds, policy.fatal_settings);
730	if (rc) {
731		dev_err(cxlds->dev, "Failed to get interrupt for event Fatal log\n");
732		return rc;
733	}
734
735	return 0;
736}
737
738static bool cxl_event_int_is_fw(u8 setting)
739{
740	u8 mode = FIELD_GET(CXLDEV_EVENT_INT_MODE_MASK, setting);
741
742	return mode == CXL_INT_FW;
743}
744
745static int cxl_event_config(struct pci_host_bridge *host_bridge,
746			    struct cxl_memdev_state *mds, bool irq_avail)
747{
748	struct cxl_event_interrupt_policy policy;
749	int rc;
750
751	/*
752	 * When BIOS maintains CXL error reporting control, it will process
753	 * event records.  Only one agent can do so.
754	 */
755	if (!host_bridge->native_cxl_error)
756		return 0;
757
758	if (!irq_avail) {
759		dev_info(mds->cxlds.dev, "No interrupt support, disable event processing.\n");
760		return 0;
761	}
762
763	rc = cxl_mem_alloc_event_buf(mds);
764	if (rc)
765		return rc;
766
767	rc = cxl_event_get_int_policy(mds, &policy);
768	if (rc)
769		return rc;
770
771	if (cxl_event_int_is_fw(policy.info_settings) ||
772	    cxl_event_int_is_fw(policy.warn_settings) ||
773	    cxl_event_int_is_fw(policy.failure_settings) ||
774	    cxl_event_int_is_fw(policy.fatal_settings)) {
775		dev_err(mds->cxlds.dev,
776			"FW still in control of Event Logs despite _OSC settings\n");
777		return -EBUSY;
778	}
779
780	rc = cxl_event_irqsetup(mds);
781	if (rc)
782		return rc;
783
784	cxl_mem_get_event_records(mds, CXLDEV_EVENT_STATUS_ALL);
785
786	return 0;
787}
788
789static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
790{
791	struct pci_host_bridge *host_bridge = pci_find_host_bridge(pdev->bus);
792	struct cxl_memdev_state *mds;
793	struct cxl_dev_state *cxlds;
794	struct cxl_register_map map;
795	struct cxl_memdev *cxlmd;
796	int i, rc, pmu_count;
797	bool irq_avail;
798
799	/*
800	 * Double check the anonymous union trickery in struct cxl_regs
801	 * FIXME switch to struct_group()
802	 */
803	BUILD_BUG_ON(offsetof(struct cxl_regs, memdev) !=
804		     offsetof(struct cxl_regs, device_regs.memdev));
805
806	rc = pcim_enable_device(pdev);
807	if (rc)
808		return rc;
809	pci_set_master(pdev);
810
811	mds = cxl_memdev_state_create(&pdev->dev);
812	if (IS_ERR(mds))
813		return PTR_ERR(mds);
814	cxlds = &mds->cxlds;
815	pci_set_drvdata(pdev, cxlds);
816
817	cxlds->rcd = is_cxl_restricted(pdev);
818	cxlds->serial = pci_get_dsn(pdev);
819	cxlds->cxl_dvsec = pci_find_dvsec_capability(
820		pdev, PCI_DVSEC_VENDOR_ID_CXL, CXL_DVSEC_PCIE_DEVICE);
821	if (!cxlds->cxl_dvsec)
822		dev_warn(&pdev->dev,
823			 "Device DVSEC not present, skip CXL.mem init\n");
824
825	rc = cxl_pci_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map);
826	if (rc)
827		return rc;
828
829	rc = cxl_map_device_regs(&map, &cxlds->regs.device_regs);
830	if (rc)
831		return rc;
832
833	/*
834	 * If the component registers can't be found, the cxl_pci driver may
835	 * still be useful for management functions so don't return an error.
836	 */
837	rc = cxl_pci_setup_regs(pdev, CXL_REGLOC_RBI_COMPONENT,
838				&cxlds->reg_map);
839	if (rc)
840		dev_warn(&pdev->dev, "No component registers (%d)\n", rc);
841	else if (!cxlds->reg_map.component_map.ras.valid)
842		dev_dbg(&pdev->dev, "RAS registers not found\n");
843
844	rc = cxl_map_component_regs(&cxlds->reg_map, &cxlds->regs.component,
845				    BIT(CXL_CM_CAP_CAP_ID_RAS));
846	if (rc)
847		dev_dbg(&pdev->dev, "Failed to map RAS capability.\n");
848
849	rc = cxl_await_media_ready(cxlds);
850	if (rc == 0)
851		cxlds->media_ready = true;
852	else
853		dev_warn(&pdev->dev, "Media not active (%d)\n", rc);
854
855	irq_avail = cxl_alloc_irq_vectors(pdev);
856
857	rc = cxl_pci_setup_mailbox(mds, irq_avail);
858	if (rc)
859		return rc;
860
861	rc = cxl_enumerate_cmds(mds);
862	if (rc)
863		return rc;
864
865	rc = cxl_set_timestamp(mds);
866	if (rc)
867		return rc;
868
869	rc = cxl_poison_state_init(mds);
870	if (rc)
871		return rc;
872
873	rc = cxl_dev_state_identify(mds);
874	if (rc)
875		return rc;
876
877	rc = cxl_mem_create_range_info(mds);
878	if (rc)
879		return rc;
880
881	cxlmd = devm_cxl_add_memdev(&pdev->dev, cxlds);
882	if (IS_ERR(cxlmd))
883		return PTR_ERR(cxlmd);
884
885	rc = devm_cxl_setup_fw_upload(&pdev->dev, mds);
886	if (rc)
887		return rc;
888
889	rc = devm_cxl_sanitize_setup_notifier(&pdev->dev, cxlmd);
890	if (rc)
891		return rc;
892
893	pmu_count = cxl_count_regblock(pdev, CXL_REGLOC_RBI_PMU);
894	for (i = 0; i < pmu_count; i++) {
895		struct cxl_pmu_regs pmu_regs;
896
897		rc = cxl_find_regblock_instance(pdev, CXL_REGLOC_RBI_PMU, &map, i);
898		if (rc) {
899			dev_dbg(&pdev->dev, "Could not find PMU regblock\n");
900			break;
901		}
902
903		rc = cxl_map_pmu_regs(&map, &pmu_regs);
904		if (rc) {
905			dev_dbg(&pdev->dev, "Could not map PMU regs\n");
906			break;
907		}
908
909		rc = devm_cxl_pmu_add(cxlds->dev, &pmu_regs, cxlmd->id, i, CXL_PMU_MEMDEV);
910		if (rc) {
911			dev_dbg(&pdev->dev, "Could not add PMU instance\n");
912			break;
913		}
914	}
915
916	rc = cxl_event_config(host_bridge, mds, irq_avail);
917	if (rc)
918		return rc;
919
920	rc = cxl_pci_ras_unmask(pdev);
921	if (rc)
922		dev_dbg(&pdev->dev, "No RAS reporting unmasked\n");
923
924	pci_save_state(pdev);
925
926	return rc;
927}
928
929static const struct pci_device_id cxl_mem_pci_tbl[] = {
930	/* PCI class code for CXL.mem Type-3 Devices */
931	{ PCI_DEVICE_CLASS((PCI_CLASS_MEMORY_CXL << 8 | CXL_MEMORY_PROGIF), ~0)},
932	{ /* terminate list */ },
933};
934MODULE_DEVICE_TABLE(pci, cxl_mem_pci_tbl);
935
936static pci_ers_result_t cxl_slot_reset(struct pci_dev *pdev)
937{
938	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
939	struct cxl_memdev *cxlmd = cxlds->cxlmd;
940	struct device *dev = &cxlmd->dev;
941
942	dev_info(&pdev->dev, "%s: restart CXL.mem after slot reset\n",
943		 dev_name(dev));
944	pci_restore_state(pdev);
945	if (device_attach(dev) <= 0)
946		return PCI_ERS_RESULT_DISCONNECT;
947	return PCI_ERS_RESULT_RECOVERED;
948}
949
950static void cxl_error_resume(struct pci_dev *pdev)
951{
952	struct cxl_dev_state *cxlds = pci_get_drvdata(pdev);
953	struct cxl_memdev *cxlmd = cxlds->cxlmd;
954	struct device *dev = &cxlmd->dev;
955
956	dev_info(&pdev->dev, "%s: error resume %s\n", dev_name(dev),
957		 dev->driver ? "successful" : "failed");
958}
959
960static const struct pci_error_handlers cxl_error_handlers = {
961	.error_detected	= cxl_error_detected,
962	.slot_reset	= cxl_slot_reset,
963	.resume		= cxl_error_resume,
964	.cor_error_detected	= cxl_cor_error_detected,
965};
966
967static struct pci_driver cxl_pci_driver = {
968	.name			= KBUILD_MODNAME,
969	.id_table		= cxl_mem_pci_tbl,
970	.probe			= cxl_pci_probe,
971	.err_handler		= &cxl_error_handlers,
972	.driver	= {
973		.probe_type	= PROBE_PREFER_ASYNCHRONOUS,
974	},
975};
976
977module_pci_driver(cxl_pci_driver);
978MODULE_LICENSE("GPL v2");
979MODULE_IMPORT_NS(CXL);
980