1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Volume Management Device driver
4 * Copyright (c) 2015, Intel Corporation.
5 */
6
7#include <linux/device.h>
8#include <linux/interrupt.h>
9#include <linux/irq.h>
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/msi.h>
13#include <linux/pci.h>
14#include <linux/pci-acpi.h>
15#include <linux/pci-ecam.h>
16#include <linux/srcu.h>
17#include <linux/rculist.h>
18#include <linux/rcupdate.h>
19
20#include <asm/irqdomain.h>
21
22#define VMD_CFGBAR	0
23#define VMD_MEMBAR1	2
24#define VMD_MEMBAR2	4
25
26#define PCI_REG_VMCAP		0x40
27#define BUS_RESTRICT_CAP(vmcap)	(vmcap & 0x1)
28#define PCI_REG_VMCONFIG	0x44
29#define BUS_RESTRICT_CFG(vmcfg)	((vmcfg >> 8) & 0x3)
30#define VMCONFIG_MSI_REMAP	0x2
31#define PCI_REG_VMLOCK		0x70
32#define MB2_SHADOW_EN(vmlock)	(vmlock & 0x2)
33
34#define MB2_SHADOW_OFFSET	0x2000
35#define MB2_SHADOW_SIZE		16
36
37enum vmd_features {
38	/*
39	 * Device may contain registers which hint the physical location of the
40	 * membars, in order to allow proper address translation during
41	 * resource assignment to enable guest virtualization
42	 */
43	VMD_FEAT_HAS_MEMBAR_SHADOW		= (1 << 0),
44
45	/*
46	 * Device may provide root port configuration information which limits
47	 * bus numbering
48	 */
49	VMD_FEAT_HAS_BUS_RESTRICTIONS		= (1 << 1),
50
51	/*
52	 * Device contains physical location shadow registers in
53	 * vendor-specific capability space
54	 */
55	VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP	= (1 << 2),
56
57	/*
58	 * Device may use MSI-X vector 0 for software triggering and will not
59	 * be used for MSI remapping
60	 */
61	VMD_FEAT_OFFSET_FIRST_VECTOR		= (1 << 3),
62
63	/*
64	 * Device can bypass remapping MSI-X transactions into its MSI-X table,
65	 * avoiding the requirement of a VMD MSI domain for child device
66	 * interrupt handling.
67	 */
68	VMD_FEAT_CAN_BYPASS_MSI_REMAP		= (1 << 4),
69
70	/*
71	 * Enable ASPM on the PCIE root ports and set the default LTR of the
72	 * storage devices on platforms where these values are not configured by
73	 * BIOS. This is needed for laptops, which require these settings for
74	 * proper power management of the SoC.
75	 */
76	VMD_FEAT_BIOS_PM_QUIRK		= (1 << 5),
77};
78
79#define VMD_BIOS_PM_QUIRK_LTR	0x1003	/* 3145728 ns */
80
81#define VMD_FEATS_CLIENT	(VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP |	\
82				 VMD_FEAT_HAS_BUS_RESTRICTIONS |	\
83				 VMD_FEAT_OFFSET_FIRST_VECTOR |		\
84				 VMD_FEAT_BIOS_PM_QUIRK)
85
86static DEFINE_IDA(vmd_instance_ida);
87
88/*
89 * Lock for manipulating VMD IRQ lists.
90 */
91static DEFINE_RAW_SPINLOCK(list_lock);
92
93/**
94 * struct vmd_irq - private data to map driver IRQ to the VMD shared vector
95 * @node:	list item for parent traversal.
96 * @irq:	back pointer to parent.
97 * @enabled:	true if driver enabled IRQ
98 * @virq:	the virtual IRQ value provided to the requesting driver.
99 *
100 * Every MSI/MSI-X IRQ requested for a device in a VMD domain will be mapped to
101 * a VMD IRQ using this structure.
102 */
103struct vmd_irq {
104	struct list_head	node;
105	struct vmd_irq_list	*irq;
106	bool			enabled;
107	unsigned int		virq;
108};
109
110/**
111 * struct vmd_irq_list - list of driver requested IRQs mapping to a VMD vector
112 * @irq_list:	the list of irq's the VMD one demuxes to.
113 * @srcu:	SRCU struct for local synchronization.
114 * @count:	number of child IRQs assigned to this vector; used to track
115 *		sharing.
116 * @virq:	The underlying VMD Linux interrupt number
117 */
118struct vmd_irq_list {
119	struct list_head	irq_list;
120	struct srcu_struct	srcu;
121	unsigned int		count;
122	unsigned int		virq;
123};
124
125struct vmd_dev {
126	struct pci_dev		*dev;
127
128	spinlock_t		cfg_lock;
129	void __iomem		*cfgbar;
130
131	int msix_count;
132	struct vmd_irq_list	*irqs;
133
134	struct pci_sysdata	sysdata;
135	struct resource		resources[3];
136	struct irq_domain	*irq_domain;
137	struct pci_bus		*bus;
138	u8			busn_start;
139	u8			first_vec;
140	char			*name;
141	int			instance;
142};
143
144static inline struct vmd_dev *vmd_from_bus(struct pci_bus *bus)
145{
146	return container_of(bus->sysdata, struct vmd_dev, sysdata);
147}
148
149static inline unsigned int index_from_irqs(struct vmd_dev *vmd,
150					   struct vmd_irq_list *irqs)
151{
152	return irqs - vmd->irqs;
153}
154
155/*
156 * Drivers managing a device in a VMD domain allocate their own IRQs as before,
157 * but the MSI entry for the hardware it's driving will be programmed with a
158 * destination ID for the VMD MSI-X table.  The VMD muxes interrupts in its
159 * domain into one of its own, and the VMD driver de-muxes these for the
160 * handlers sharing that VMD IRQ.  The vmd irq_domain provides the operations
161 * and irq_chip to set this up.
162 */
163static void vmd_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
164{
165	struct vmd_irq *vmdirq = data->chip_data;
166	struct vmd_irq_list *irq = vmdirq->irq;
167	struct vmd_dev *vmd = irq_data_get_irq_handler_data(data);
168
169	memset(msg, 0, sizeof(*msg));
170	msg->address_hi = X86_MSI_BASE_ADDRESS_HIGH;
171	msg->arch_addr_lo.base_address = X86_MSI_BASE_ADDRESS_LOW;
172	msg->arch_addr_lo.destid_0_7 = index_from_irqs(vmd, irq);
173}
174
175/*
176 * We rely on MSI_FLAG_USE_DEF_CHIP_OPS to set the IRQ mask/unmask ops.
177 */
178static void vmd_irq_enable(struct irq_data *data)
179{
180	struct vmd_irq *vmdirq = data->chip_data;
181	unsigned long flags;
182
183	raw_spin_lock_irqsave(&list_lock, flags);
184	WARN_ON(vmdirq->enabled);
185	list_add_tail_rcu(&vmdirq->node, &vmdirq->irq->irq_list);
186	vmdirq->enabled = true;
187	raw_spin_unlock_irqrestore(&list_lock, flags);
188
189	data->chip->irq_unmask(data);
190}
191
192static void vmd_irq_disable(struct irq_data *data)
193{
194	struct vmd_irq *vmdirq = data->chip_data;
195	unsigned long flags;
196
197	data->chip->irq_mask(data);
198
199	raw_spin_lock_irqsave(&list_lock, flags);
200	if (vmdirq->enabled) {
201		list_del_rcu(&vmdirq->node);
202		vmdirq->enabled = false;
203	}
204	raw_spin_unlock_irqrestore(&list_lock, flags);
205}
206
207/*
208 * XXX: Stubbed until we develop acceptable way to not create conflicts with
209 * other devices sharing the same vector.
210 */
211static int vmd_irq_set_affinity(struct irq_data *data,
212				const struct cpumask *dest, bool force)
213{
214	return -EINVAL;
215}
216
217static struct irq_chip vmd_msi_controller = {
218	.name			= "VMD-MSI",
219	.irq_enable		= vmd_irq_enable,
220	.irq_disable		= vmd_irq_disable,
221	.irq_compose_msi_msg	= vmd_compose_msi_msg,
222	.irq_set_affinity	= vmd_irq_set_affinity,
223};
224
225static irq_hw_number_t vmd_get_hwirq(struct msi_domain_info *info,
226				     msi_alloc_info_t *arg)
227{
228	return 0;
229}
230
231/*
232 * XXX: We can be even smarter selecting the best IRQ once we solve the
233 * affinity problem.
234 */
235static struct vmd_irq_list *vmd_next_irq(struct vmd_dev *vmd, struct msi_desc *desc)
236{
237	unsigned long flags;
238	int i, best;
239
240	if (vmd->msix_count == 1 + vmd->first_vec)
241		return &vmd->irqs[vmd->first_vec];
242
243	/*
244	 * White list for fast-interrupt handlers. All others will share the
245	 * "slow" interrupt vector.
246	 */
247	switch (msi_desc_to_pci_dev(desc)->class) {
248	case PCI_CLASS_STORAGE_EXPRESS:
249		break;
250	default:
251		return &vmd->irqs[vmd->first_vec];
252	}
253
254	raw_spin_lock_irqsave(&list_lock, flags);
255	best = vmd->first_vec + 1;
256	for (i = best; i < vmd->msix_count; i++)
257		if (vmd->irqs[i].count < vmd->irqs[best].count)
258			best = i;
259	vmd->irqs[best].count++;
260	raw_spin_unlock_irqrestore(&list_lock, flags);
261
262	return &vmd->irqs[best];
263}
264
265static int vmd_msi_init(struct irq_domain *domain, struct msi_domain_info *info,
266			unsigned int virq, irq_hw_number_t hwirq,
267			msi_alloc_info_t *arg)
268{
269	struct msi_desc *desc = arg->desc;
270	struct vmd_dev *vmd = vmd_from_bus(msi_desc_to_pci_dev(desc)->bus);
271	struct vmd_irq *vmdirq = kzalloc(sizeof(*vmdirq), GFP_KERNEL);
272
273	if (!vmdirq)
274		return -ENOMEM;
275
276	INIT_LIST_HEAD(&vmdirq->node);
277	vmdirq->irq = vmd_next_irq(vmd, desc);
278	vmdirq->virq = virq;
279
280	irq_domain_set_info(domain, virq, vmdirq->irq->virq, info->chip, vmdirq,
281			    handle_untracked_irq, vmd, NULL);
282	return 0;
283}
284
285static void vmd_msi_free(struct irq_domain *domain,
286			struct msi_domain_info *info, unsigned int virq)
287{
288	struct vmd_irq *vmdirq = irq_get_chip_data(virq);
289	unsigned long flags;
290
291	synchronize_srcu(&vmdirq->irq->srcu);
292
293	/* XXX: Potential optimization to rebalance */
294	raw_spin_lock_irqsave(&list_lock, flags);
295	vmdirq->irq->count--;
296	raw_spin_unlock_irqrestore(&list_lock, flags);
297
298	kfree(vmdirq);
299}
300
301static int vmd_msi_prepare(struct irq_domain *domain, struct device *dev,
302			   int nvec, msi_alloc_info_t *arg)
303{
304	struct pci_dev *pdev = to_pci_dev(dev);
305	struct vmd_dev *vmd = vmd_from_bus(pdev->bus);
306
307	if (nvec > vmd->msix_count)
308		return vmd->msix_count;
309
310	memset(arg, 0, sizeof(*arg));
311	return 0;
312}
313
314static void vmd_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
315{
316	arg->desc = desc;
317}
318
319static struct msi_domain_ops vmd_msi_domain_ops = {
320	.get_hwirq	= vmd_get_hwirq,
321	.msi_init	= vmd_msi_init,
322	.msi_free	= vmd_msi_free,
323	.msi_prepare	= vmd_msi_prepare,
324	.set_desc	= vmd_set_desc,
325};
326
327static struct msi_domain_info vmd_msi_domain_info = {
328	.flags		= MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
329			  MSI_FLAG_PCI_MSIX,
330	.ops		= &vmd_msi_domain_ops,
331	.chip		= &vmd_msi_controller,
332};
333
334static void vmd_set_msi_remapping(struct vmd_dev *vmd, bool enable)
335{
336	u16 reg;
337
338	pci_read_config_word(vmd->dev, PCI_REG_VMCONFIG, &reg);
339	reg = enable ? (reg & ~VMCONFIG_MSI_REMAP) :
340		       (reg | VMCONFIG_MSI_REMAP);
341	pci_write_config_word(vmd->dev, PCI_REG_VMCONFIG, reg);
342}
343
344static int vmd_create_irq_domain(struct vmd_dev *vmd)
345{
346	struct fwnode_handle *fn;
347
348	fn = irq_domain_alloc_named_id_fwnode("VMD-MSI", vmd->sysdata.domain);
349	if (!fn)
350		return -ENODEV;
351
352	vmd->irq_domain = pci_msi_create_irq_domain(fn, &vmd_msi_domain_info, NULL);
353	if (!vmd->irq_domain) {
354		irq_domain_free_fwnode(fn);
355		return -ENODEV;
356	}
357
358	return 0;
359}
360
361static void vmd_remove_irq_domain(struct vmd_dev *vmd)
362{
363	/*
364	 * Some production BIOS won't enable remapping between soft reboots.
365	 * Ensure remapping is restored before unloading the driver.
366	 */
367	if (!vmd->msix_count)
368		vmd_set_msi_remapping(vmd, true);
369
370	if (vmd->irq_domain) {
371		struct fwnode_handle *fn = vmd->irq_domain->fwnode;
372
373		irq_domain_remove(vmd->irq_domain);
374		irq_domain_free_fwnode(fn);
375	}
376}
377
378static void __iomem *vmd_cfg_addr(struct vmd_dev *vmd, struct pci_bus *bus,
379				  unsigned int devfn, int reg, int len)
380{
381	unsigned int busnr_ecam = bus->number - vmd->busn_start;
382	u32 offset = PCIE_ECAM_OFFSET(busnr_ecam, devfn, reg);
383
384	if (offset + len >= resource_size(&vmd->dev->resource[VMD_CFGBAR]))
385		return NULL;
386
387	return vmd->cfgbar + offset;
388}
389
390/*
391 * CPU may deadlock if config space is not serialized on some versions of this
392 * hardware, so all config space access is done under a spinlock.
393 */
394static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg,
395			int len, u32 *value)
396{
397	struct vmd_dev *vmd = vmd_from_bus(bus);
398	void __iomem *addr = vmd_cfg_addr(vmd, bus, devfn, reg, len);
399	unsigned long flags;
400	int ret = 0;
401
402	if (!addr)
403		return -EFAULT;
404
405	spin_lock_irqsave(&vmd->cfg_lock, flags);
406	switch (len) {
407	case 1:
408		*value = readb(addr);
409		break;
410	case 2:
411		*value = readw(addr);
412		break;
413	case 4:
414		*value = readl(addr);
415		break;
416	default:
417		ret = -EINVAL;
418		break;
419	}
420	spin_unlock_irqrestore(&vmd->cfg_lock, flags);
421	return ret;
422}
423
424/*
425 * VMD h/w converts non-posted config writes to posted memory writes. The
426 * read-back in this function forces the completion so it returns only after
427 * the config space was written, as expected.
428 */
429static int vmd_pci_write(struct pci_bus *bus, unsigned int devfn, int reg,
430			 int len, u32 value)
431{
432	struct vmd_dev *vmd = vmd_from_bus(bus);
433	void __iomem *addr = vmd_cfg_addr(vmd, bus, devfn, reg, len);
434	unsigned long flags;
435	int ret = 0;
436
437	if (!addr)
438		return -EFAULT;
439
440	spin_lock_irqsave(&vmd->cfg_lock, flags);
441	switch (len) {
442	case 1:
443		writeb(value, addr);
444		readb(addr);
445		break;
446	case 2:
447		writew(value, addr);
448		readw(addr);
449		break;
450	case 4:
451		writel(value, addr);
452		readl(addr);
453		break;
454	default:
455		ret = -EINVAL;
456		break;
457	}
458	spin_unlock_irqrestore(&vmd->cfg_lock, flags);
459	return ret;
460}
461
462static struct pci_ops vmd_ops = {
463	.read		= vmd_pci_read,
464	.write		= vmd_pci_write,
465};
466
467#ifdef CONFIG_ACPI
468static struct acpi_device *vmd_acpi_find_companion(struct pci_dev *pci_dev)
469{
470	struct pci_host_bridge *bridge;
471	u32 busnr, addr;
472
473	if (pci_dev->bus->ops != &vmd_ops)
474		return NULL;
475
476	bridge = pci_find_host_bridge(pci_dev->bus);
477	busnr = pci_dev->bus->number - bridge->bus->number;
478	/*
479	 * The address computation below is only applicable to relative bus
480	 * numbers below 32.
481	 */
482	if (busnr > 31)
483		return NULL;
484
485	addr = (busnr << 24) | ((u32)pci_dev->devfn << 16) | 0x8000FFFFU;
486
487	dev_dbg(&pci_dev->dev, "Looking for ACPI companion (address 0x%x)\n",
488		addr);
489
490	return acpi_find_child_device(ACPI_COMPANION(bridge->dev.parent), addr,
491				      false);
492}
493
494static bool hook_installed;
495
496static void vmd_acpi_begin(void)
497{
498	if (pci_acpi_set_companion_lookup_hook(vmd_acpi_find_companion))
499		return;
500
501	hook_installed = true;
502}
503
504static void vmd_acpi_end(void)
505{
506	if (!hook_installed)
507		return;
508
509	pci_acpi_clear_companion_lookup_hook();
510	hook_installed = false;
511}
512#else
513static inline void vmd_acpi_begin(void) { }
514static inline void vmd_acpi_end(void) { }
515#endif /* CONFIG_ACPI */
516
517static void vmd_domain_reset(struct vmd_dev *vmd)
518{
519	u16 bus, max_buses = resource_size(&vmd->resources[0]);
520	u8 dev, functions, fn, hdr_type;
521	char __iomem *base;
522
523	for (bus = 0; bus < max_buses; bus++) {
524		for (dev = 0; dev < 32; dev++) {
525			base = vmd->cfgbar + PCIE_ECAM_OFFSET(bus,
526						PCI_DEVFN(dev, 0), 0);
527
528			hdr_type = readb(base + PCI_HEADER_TYPE);
529
530			functions = (hdr_type & 0x80) ? 8 : 1;
531			for (fn = 0; fn < functions; fn++) {
532				base = vmd->cfgbar + PCIE_ECAM_OFFSET(bus,
533						PCI_DEVFN(dev, fn), 0);
534
535				hdr_type = readb(base + PCI_HEADER_TYPE) &
536						PCI_HEADER_TYPE_MASK;
537
538				if (hdr_type != PCI_HEADER_TYPE_BRIDGE ||
539				    (readw(base + PCI_CLASS_DEVICE) !=
540				     PCI_CLASS_BRIDGE_PCI))
541					continue;
542
543				/*
544				 * Temporarily disable the I/O range before updating
545				 * PCI_IO_BASE.
546				 */
547				writel(0x0000ffff, base + PCI_IO_BASE_UPPER16);
548				/* Update lower 16 bits of I/O base/limit */
549				writew(0x00f0, base + PCI_IO_BASE);
550				/* Update upper 16 bits of I/O base/limit */
551				writel(0, base + PCI_IO_BASE_UPPER16);
552
553				/* MMIO Base/Limit */
554				writel(0x0000fff0, base + PCI_MEMORY_BASE);
555
556				/* Prefetchable MMIO Base/Limit */
557				writel(0, base + PCI_PREF_LIMIT_UPPER32);
558				writel(0x0000fff0, base + PCI_PREF_MEMORY_BASE);
559				writel(0xffffffff, base + PCI_PREF_BASE_UPPER32);
560			}
561		}
562	}
563}
564
565static void vmd_attach_resources(struct vmd_dev *vmd)
566{
567	vmd->dev->resource[VMD_MEMBAR1].child = &vmd->resources[1];
568	vmd->dev->resource[VMD_MEMBAR2].child = &vmd->resources[2];
569}
570
571static void vmd_detach_resources(struct vmd_dev *vmd)
572{
573	vmd->dev->resource[VMD_MEMBAR1].child = NULL;
574	vmd->dev->resource[VMD_MEMBAR2].child = NULL;
575}
576
577/*
578 * VMD domains start at 0x10000 to not clash with ACPI _SEG domains.
579 * Per ACPI r6.0, sec 6.5.6,  _SEG returns an integer, of which the lower
580 * 16 bits are the PCI Segment Group (domain) number.  Other bits are
581 * currently reserved.
582 */
583static int vmd_find_free_domain(void)
584{
585	int domain = 0xffff;
586	struct pci_bus *bus = NULL;
587
588	while ((bus = pci_find_next_bus(bus)) != NULL)
589		domain = max_t(int, domain, pci_domain_nr(bus));
590	return domain + 1;
591}
592
593static int vmd_get_phys_offsets(struct vmd_dev *vmd, bool native_hint,
594				resource_size_t *offset1,
595				resource_size_t *offset2)
596{
597	struct pci_dev *dev = vmd->dev;
598	u64 phys1, phys2;
599
600	if (native_hint) {
601		u32 vmlock;
602		int ret;
603
604		ret = pci_read_config_dword(dev, PCI_REG_VMLOCK, &vmlock);
605		if (ret || PCI_POSSIBLE_ERROR(vmlock))
606			return -ENODEV;
607
608		if (MB2_SHADOW_EN(vmlock)) {
609			void __iomem *membar2;
610
611			membar2 = pci_iomap(dev, VMD_MEMBAR2, 0);
612			if (!membar2)
613				return -ENOMEM;
614			phys1 = readq(membar2 + MB2_SHADOW_OFFSET);
615			phys2 = readq(membar2 + MB2_SHADOW_OFFSET + 8);
616			pci_iounmap(dev, membar2);
617		} else
618			return 0;
619	} else {
620		/* Hypervisor-Emulated Vendor-Specific Capability */
621		int pos = pci_find_capability(dev, PCI_CAP_ID_VNDR);
622		u32 reg, regu;
623
624		pci_read_config_dword(dev, pos + 4, &reg);
625
626		/* "SHDW" */
627		if (pos && reg == 0x53484457) {
628			pci_read_config_dword(dev, pos + 8, &reg);
629			pci_read_config_dword(dev, pos + 12, &regu);
630			phys1 = (u64) regu << 32 | reg;
631
632			pci_read_config_dword(dev, pos + 16, &reg);
633			pci_read_config_dword(dev, pos + 20, &regu);
634			phys2 = (u64) regu << 32 | reg;
635		} else
636			return 0;
637	}
638
639	*offset1 = dev->resource[VMD_MEMBAR1].start -
640			(phys1 & PCI_BASE_ADDRESS_MEM_MASK);
641	*offset2 = dev->resource[VMD_MEMBAR2].start -
642			(phys2 & PCI_BASE_ADDRESS_MEM_MASK);
643
644	return 0;
645}
646
647static int vmd_get_bus_number_start(struct vmd_dev *vmd)
648{
649	struct pci_dev *dev = vmd->dev;
650	u16 reg;
651
652	pci_read_config_word(dev, PCI_REG_VMCAP, &reg);
653	if (BUS_RESTRICT_CAP(reg)) {
654		pci_read_config_word(dev, PCI_REG_VMCONFIG, &reg);
655
656		switch (BUS_RESTRICT_CFG(reg)) {
657		case 0:
658			vmd->busn_start = 0;
659			break;
660		case 1:
661			vmd->busn_start = 128;
662			break;
663		case 2:
664			vmd->busn_start = 224;
665			break;
666		default:
667			pci_err(dev, "Unknown Bus Offset Setting (%d)\n",
668				BUS_RESTRICT_CFG(reg));
669			return -ENODEV;
670		}
671	}
672
673	return 0;
674}
675
676static irqreturn_t vmd_irq(int irq, void *data)
677{
678	struct vmd_irq_list *irqs = data;
679	struct vmd_irq *vmdirq;
680	int idx;
681
682	idx = srcu_read_lock(&irqs->srcu);
683	list_for_each_entry_rcu(vmdirq, &irqs->irq_list, node)
684		generic_handle_irq(vmdirq->virq);
685	srcu_read_unlock(&irqs->srcu, idx);
686
687	return IRQ_HANDLED;
688}
689
690static int vmd_alloc_irqs(struct vmd_dev *vmd)
691{
692	struct pci_dev *dev = vmd->dev;
693	int i, err;
694
695	vmd->msix_count = pci_msix_vec_count(dev);
696	if (vmd->msix_count < 0)
697		return -ENODEV;
698
699	vmd->msix_count = pci_alloc_irq_vectors(dev, vmd->first_vec + 1,
700						vmd->msix_count, PCI_IRQ_MSIX);
701	if (vmd->msix_count < 0)
702		return vmd->msix_count;
703
704	vmd->irqs = devm_kcalloc(&dev->dev, vmd->msix_count, sizeof(*vmd->irqs),
705				 GFP_KERNEL);
706	if (!vmd->irqs)
707		return -ENOMEM;
708
709	for (i = 0; i < vmd->msix_count; i++) {
710		err = init_srcu_struct(&vmd->irqs[i].srcu);
711		if (err)
712			return err;
713
714		INIT_LIST_HEAD(&vmd->irqs[i].irq_list);
715		vmd->irqs[i].virq = pci_irq_vector(dev, i);
716		err = devm_request_irq(&dev->dev, vmd->irqs[i].virq,
717				       vmd_irq, IRQF_NO_THREAD,
718				       vmd->name, &vmd->irqs[i]);
719		if (err)
720			return err;
721	}
722
723	return 0;
724}
725
726/*
727 * Since VMD is an aperture to regular PCIe root ports, only allow it to
728 * control features that the OS is allowed to control on the physical PCI bus.
729 */
730static void vmd_copy_host_bridge_flags(struct pci_host_bridge *root_bridge,
731				       struct pci_host_bridge *vmd_bridge)
732{
733	vmd_bridge->native_pcie_hotplug = root_bridge->native_pcie_hotplug;
734	vmd_bridge->native_shpc_hotplug = root_bridge->native_shpc_hotplug;
735	vmd_bridge->native_aer = root_bridge->native_aer;
736	vmd_bridge->native_pme = root_bridge->native_pme;
737	vmd_bridge->native_ltr = root_bridge->native_ltr;
738	vmd_bridge->native_dpc = root_bridge->native_dpc;
739}
740
741/*
742 * Enable ASPM and LTR settings on devices that aren't configured by BIOS.
743 */
744static int vmd_pm_enable_quirk(struct pci_dev *pdev, void *userdata)
745{
746	unsigned long features = *(unsigned long *)userdata;
747	u16 ltr = VMD_BIOS_PM_QUIRK_LTR;
748	u32 ltr_reg;
749	int pos;
750
751	if (!(features & VMD_FEAT_BIOS_PM_QUIRK))
752		return 0;
753
754	pci_enable_link_state_locked(pdev, PCIE_LINK_STATE_ALL);
755
756	pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_LTR);
757	if (!pos)
758		return 0;
759
760	/*
761	 * Skip if the max snoop LTR is non-zero, indicating BIOS has set it
762	 * so the LTR quirk is not needed.
763	 */
764	pci_read_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, &ltr_reg);
765	if (!!(ltr_reg & (PCI_LTR_VALUE_MASK | PCI_LTR_SCALE_MASK)))
766		return 0;
767
768	/*
769	 * Set the default values to the maximum required by the platform to
770	 * allow the deepest power management savings. Write as a DWORD where
771	 * the lower word is the max snoop latency and the upper word is the
772	 * max non-snoop latency.
773	 */
774	ltr_reg = (ltr << 16) | ltr;
775	pci_write_config_dword(pdev, pos + PCI_LTR_MAX_SNOOP_LAT, ltr_reg);
776	pci_info(pdev, "VMD: Default LTR value set by driver\n");
777
778	return 0;
779}
780
781static int vmd_enable_domain(struct vmd_dev *vmd, unsigned long features)
782{
783	struct pci_sysdata *sd = &vmd->sysdata;
784	struct resource *res;
785	u32 upper_bits;
786	unsigned long flags;
787	LIST_HEAD(resources);
788	resource_size_t offset[2] = {0};
789	resource_size_t membar2_offset = 0x2000;
790	struct pci_bus *child;
791	struct pci_dev *dev;
792	int ret;
793
794	/*
795	 * Shadow registers may exist in certain VMD device ids which allow
796	 * guests to correctly assign host physical addresses to the root ports
797	 * and child devices. These registers will either return the host value
798	 * or 0, depending on an enable bit in the VMD device.
799	 */
800	if (features & VMD_FEAT_HAS_MEMBAR_SHADOW) {
801		membar2_offset = MB2_SHADOW_OFFSET + MB2_SHADOW_SIZE;
802		ret = vmd_get_phys_offsets(vmd, true, &offset[0], &offset[1]);
803		if (ret)
804			return ret;
805	} else if (features & VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP) {
806		ret = vmd_get_phys_offsets(vmd, false, &offset[0], &offset[1]);
807		if (ret)
808			return ret;
809	}
810
811	/*
812	 * Certain VMD devices may have a root port configuration option which
813	 * limits the bus range to between 0-127, 128-255, or 224-255
814	 */
815	if (features & VMD_FEAT_HAS_BUS_RESTRICTIONS) {
816		ret = vmd_get_bus_number_start(vmd);
817		if (ret)
818			return ret;
819	}
820
821	res = &vmd->dev->resource[VMD_CFGBAR];
822	vmd->resources[0] = (struct resource) {
823		.name  = "VMD CFGBAR",
824		.start = vmd->busn_start,
825		.end   = vmd->busn_start + (resource_size(res) >> 20) - 1,
826		.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED,
827	};
828
829	/*
830	 * If the window is below 4GB, clear IORESOURCE_MEM_64 so we can
831	 * put 32-bit resources in the window.
832	 *
833	 * There's no hardware reason why a 64-bit window *couldn't*
834	 * contain a 32-bit resource, but pbus_size_mem() computes the
835	 * bridge window size assuming a 64-bit window will contain no
836	 * 32-bit resources.  __pci_assign_resource() enforces that
837	 * artificial restriction to make sure everything will fit.
838	 *
839	 * The only way we could use a 64-bit non-prefetchable MEMBAR is
840	 * if its address is <4GB so that we can convert it to a 32-bit
841	 * resource.  To be visible to the host OS, all VMD endpoints must
842	 * be initially configured by platform BIOS, which includes setting
843	 * up these resources.  We can assume the device is configured
844	 * according to the platform needs.
845	 */
846	res = &vmd->dev->resource[VMD_MEMBAR1];
847	upper_bits = upper_32_bits(res->end);
848	flags = res->flags & ~IORESOURCE_SIZEALIGN;
849	if (!upper_bits)
850		flags &= ~IORESOURCE_MEM_64;
851	vmd->resources[1] = (struct resource) {
852		.name  = "VMD MEMBAR1",
853		.start = res->start,
854		.end   = res->end,
855		.flags = flags,
856		.parent = res,
857	};
858
859	res = &vmd->dev->resource[VMD_MEMBAR2];
860	upper_bits = upper_32_bits(res->end);
861	flags = res->flags & ~IORESOURCE_SIZEALIGN;
862	if (!upper_bits)
863		flags &= ~IORESOURCE_MEM_64;
864	vmd->resources[2] = (struct resource) {
865		.name  = "VMD MEMBAR2",
866		.start = res->start + membar2_offset,
867		.end   = res->end,
868		.flags = flags,
869		.parent = res,
870	};
871
872	sd->vmd_dev = vmd->dev;
873	sd->domain = vmd_find_free_domain();
874	if (sd->domain < 0)
875		return sd->domain;
876
877	sd->node = pcibus_to_node(vmd->dev->bus);
878
879	/*
880	 * Currently MSI remapping must be enabled in guest passthrough mode
881	 * due to some missing interrupt remapping plumbing. This is probably
882	 * acceptable because the guest is usually CPU-limited and MSI
883	 * remapping doesn't become a performance bottleneck.
884	 */
885	if (!(features & VMD_FEAT_CAN_BYPASS_MSI_REMAP) ||
886	    offset[0] || offset[1]) {
887		ret = vmd_alloc_irqs(vmd);
888		if (ret)
889			return ret;
890
891		vmd_set_msi_remapping(vmd, true);
892
893		ret = vmd_create_irq_domain(vmd);
894		if (ret)
895			return ret;
896
897		/*
898		 * Override the IRQ domain bus token so the domain can be
899		 * distinguished from a regular PCI/MSI domain.
900		 */
901		irq_domain_update_bus_token(vmd->irq_domain, DOMAIN_BUS_VMD_MSI);
902	} else {
903		vmd_set_msi_remapping(vmd, false);
904	}
905
906	pci_add_resource(&resources, &vmd->resources[0]);
907	pci_add_resource_offset(&resources, &vmd->resources[1], offset[0]);
908	pci_add_resource_offset(&resources, &vmd->resources[2], offset[1]);
909
910	vmd->bus = pci_create_root_bus(&vmd->dev->dev, vmd->busn_start,
911				       &vmd_ops, sd, &resources);
912	if (!vmd->bus) {
913		pci_free_resource_list(&resources);
914		vmd_remove_irq_domain(vmd);
915		return -ENODEV;
916	}
917
918	vmd_copy_host_bridge_flags(pci_find_host_bridge(vmd->dev->bus),
919				   to_pci_host_bridge(vmd->bus->bridge));
920
921	vmd_attach_resources(vmd);
922	if (vmd->irq_domain)
923		dev_set_msi_domain(&vmd->bus->dev, vmd->irq_domain);
924	else
925		dev_set_msi_domain(&vmd->bus->dev,
926				   dev_get_msi_domain(&vmd->dev->dev));
927
928	vmd_acpi_begin();
929
930	pci_scan_child_bus(vmd->bus);
931	vmd_domain_reset(vmd);
932
933	/* When Intel VMD is enabled, the OS does not discover the Root Ports
934	 * owned by Intel VMD within the MMCFG space. pci_reset_bus() applies
935	 * a reset to the parent of the PCI device supplied as argument. This
936	 * is why we pass a child device, so the reset can be triggered at
937	 * the Intel bridge level and propagated to all the children in the
938	 * hierarchy.
939	 */
940	list_for_each_entry(child, &vmd->bus->children, node) {
941		if (!list_empty(&child->devices)) {
942			dev = list_first_entry(&child->devices,
943					       struct pci_dev, bus_list);
944			ret = pci_reset_bus(dev);
945			if (ret)
946				pci_warn(dev, "can't reset device: %d\n", ret);
947
948			break;
949		}
950	}
951
952	pci_assign_unassigned_bus_resources(vmd->bus);
953
954	pci_walk_bus(vmd->bus, vmd_pm_enable_quirk, &features);
955
956	/*
957	 * VMD root buses are virtual and don't return true on pci_is_pcie()
958	 * and will fail pcie_bus_configure_settings() early. It can instead be
959	 * run on each of the real root ports.
960	 */
961	list_for_each_entry(child, &vmd->bus->children, node)
962		pcie_bus_configure_settings(child);
963
964	pci_bus_add_devices(vmd->bus);
965
966	vmd_acpi_end();
967
968	WARN(sysfs_create_link(&vmd->dev->dev.kobj, &vmd->bus->dev.kobj,
969			       "domain"), "Can't create symlink to domain\n");
970	return 0;
971}
972
973static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id)
974{
975	unsigned long features = (unsigned long) id->driver_data;
976	struct vmd_dev *vmd;
977	int err;
978
979	if (resource_size(&dev->resource[VMD_CFGBAR]) < (1 << 20))
980		return -ENOMEM;
981
982	vmd = devm_kzalloc(&dev->dev, sizeof(*vmd), GFP_KERNEL);
983	if (!vmd)
984		return -ENOMEM;
985
986	vmd->dev = dev;
987	vmd->instance = ida_simple_get(&vmd_instance_ida, 0, 0, GFP_KERNEL);
988	if (vmd->instance < 0)
989		return vmd->instance;
990
991	vmd->name = devm_kasprintf(&dev->dev, GFP_KERNEL, "vmd%d",
992				   vmd->instance);
993	if (!vmd->name) {
994		err = -ENOMEM;
995		goto out_release_instance;
996	}
997
998	err = pcim_enable_device(dev);
999	if (err < 0)
1000		goto out_release_instance;
1001
1002	vmd->cfgbar = pcim_iomap(dev, VMD_CFGBAR, 0);
1003	if (!vmd->cfgbar) {
1004		err = -ENOMEM;
1005		goto out_release_instance;
1006	}
1007
1008	pci_set_master(dev);
1009	if (dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(64)) &&
1010	    dma_set_mask_and_coherent(&dev->dev, DMA_BIT_MASK(32))) {
1011		err = -ENODEV;
1012		goto out_release_instance;
1013	}
1014
1015	if (features & VMD_FEAT_OFFSET_FIRST_VECTOR)
1016		vmd->first_vec = 1;
1017
1018	spin_lock_init(&vmd->cfg_lock);
1019	pci_set_drvdata(dev, vmd);
1020	err = vmd_enable_domain(vmd, features);
1021	if (err)
1022		goto out_release_instance;
1023
1024	dev_info(&vmd->dev->dev, "Bound to PCI domain %04x\n",
1025		 vmd->sysdata.domain);
1026	return 0;
1027
1028 out_release_instance:
1029	ida_simple_remove(&vmd_instance_ida, vmd->instance);
1030	return err;
1031}
1032
1033static void vmd_cleanup_srcu(struct vmd_dev *vmd)
1034{
1035	int i;
1036
1037	for (i = 0; i < vmd->msix_count; i++)
1038		cleanup_srcu_struct(&vmd->irqs[i].srcu);
1039}
1040
1041static void vmd_remove(struct pci_dev *dev)
1042{
1043	struct vmd_dev *vmd = pci_get_drvdata(dev);
1044
1045	sysfs_remove_link(&vmd->dev->dev.kobj, "domain");
1046	pci_stop_root_bus(vmd->bus);
1047	pci_remove_root_bus(vmd->bus);
1048	vmd_cleanup_srcu(vmd);
1049	vmd_detach_resources(vmd);
1050	vmd_remove_irq_domain(vmd);
1051	ida_simple_remove(&vmd_instance_ida, vmd->instance);
1052}
1053
1054static void vmd_shutdown(struct pci_dev *dev)
1055{
1056        struct vmd_dev *vmd = pci_get_drvdata(dev);
1057
1058        vmd_remove_irq_domain(vmd);
1059}
1060
1061#ifdef CONFIG_PM_SLEEP
1062static int vmd_suspend(struct device *dev)
1063{
1064	struct pci_dev *pdev = to_pci_dev(dev);
1065	struct vmd_dev *vmd = pci_get_drvdata(pdev);
1066	int i;
1067
1068	for (i = 0; i < vmd->msix_count; i++)
1069		devm_free_irq(dev, vmd->irqs[i].virq, &vmd->irqs[i]);
1070
1071	return 0;
1072}
1073
1074static int vmd_resume(struct device *dev)
1075{
1076	struct pci_dev *pdev = to_pci_dev(dev);
1077	struct vmd_dev *vmd = pci_get_drvdata(pdev);
1078	int err, i;
1079
1080       if (vmd->irq_domain)
1081               vmd_set_msi_remapping(vmd, true);
1082       else
1083               vmd_set_msi_remapping(vmd, false);
1084
1085	for (i = 0; i < vmd->msix_count; i++) {
1086		err = devm_request_irq(dev, vmd->irqs[i].virq,
1087				       vmd_irq, IRQF_NO_THREAD,
1088				       vmd->name, &vmd->irqs[i]);
1089		if (err)
1090			return err;
1091	}
1092
1093	return 0;
1094}
1095#endif
1096static SIMPLE_DEV_PM_OPS(vmd_dev_pm_ops, vmd_suspend, vmd_resume);
1097
1098static const struct pci_device_id vmd_ids[] = {
1099	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_201D),
1100		.driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW_VSCAP,},
1101	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_28C0),
1102		.driver_data = VMD_FEAT_HAS_MEMBAR_SHADOW |
1103				VMD_FEAT_HAS_BUS_RESTRICTIONS |
1104				VMD_FEAT_CAN_BYPASS_MSI_REMAP,},
1105	{PCI_VDEVICE(INTEL, 0x467f),
1106		.driver_data = VMD_FEATS_CLIENT,},
1107	{PCI_VDEVICE(INTEL, 0x4c3d),
1108		.driver_data = VMD_FEATS_CLIENT,},
1109	{PCI_VDEVICE(INTEL, 0xa77f),
1110		.driver_data = VMD_FEATS_CLIENT,},
1111	{PCI_VDEVICE(INTEL, 0x7d0b),
1112		.driver_data = VMD_FEATS_CLIENT,},
1113	{PCI_VDEVICE(INTEL, 0xad0b),
1114		.driver_data = VMD_FEATS_CLIENT,},
1115	{PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_9A0B),
1116		.driver_data = VMD_FEATS_CLIENT,},
1117	{0,}
1118};
1119MODULE_DEVICE_TABLE(pci, vmd_ids);
1120
1121static struct pci_driver vmd_drv = {
1122	.name		= "vmd",
1123	.id_table	= vmd_ids,
1124	.probe		= vmd_probe,
1125	.remove		= vmd_remove,
1126	.shutdown	= vmd_shutdown,
1127	.driver		= {
1128		.pm	= &vmd_dev_pm_ops,
1129	},
1130};
1131module_pci_driver(vmd_drv);
1132
1133MODULE_AUTHOR("Intel Corporation");
1134MODULE_LICENSE("GPL v2");
1135MODULE_VERSION("0.6");
1136