1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * VMware VMCI Driver
4 *
5 * Copyright (C) 2012 VMware, Inc. All rights reserved.
6 */
7
8#include <linux/vmw_vmci_defs.h>
9#include <linux/vmw_vmci_api.h>
10#include <linux/moduleparam.h>
11#include <linux/interrupt.h>
12#include <linux/highmem.h>
13#include <linux/kernel.h>
14#include <linux/mm.h>
15#include <linux/module.h>
16#include <linux/processor.h>
17#include <linux/sched.h>
18#include <linux/slab.h>
19#include <linux/init.h>
20#include <linux/pci.h>
21#include <linux/smp.h>
22#include <linux/io.h>
23#include <linux/vmalloc.h>
24
25#include "vmci_datagram.h"
26#include "vmci_doorbell.h"
27#include "vmci_context.h"
28#include "vmci_driver.h"
29#include "vmci_event.h"
30
31#define PCI_DEVICE_ID_VMWARE_VMCI	0x0740
32
33#define VMCI_UTIL_NUM_RESOURCES 1
34
35/*
36 * Datagram buffers for DMA send/receive must accommodate at least
37 * a maximum sized datagram and the header.
38 */
39#define VMCI_DMA_DG_BUFFER_SIZE (VMCI_MAX_DG_SIZE + PAGE_SIZE)
40
41static bool vmci_disable_msi;
42module_param_named(disable_msi, vmci_disable_msi, bool, 0);
43MODULE_PARM_DESC(disable_msi, "Disable MSI use in driver - (default=0)");
44
45static bool vmci_disable_msix;
46module_param_named(disable_msix, vmci_disable_msix, bool, 0);
47MODULE_PARM_DESC(disable_msix, "Disable MSI-X use in driver - (default=0)");
48
49static u32 ctx_update_sub_id = VMCI_INVALID_ID;
50static u32 vm_context_id = VMCI_INVALID_ID;
51
52struct vmci_guest_device {
53	struct device *dev;	/* PCI device we are attached to */
54	void __iomem *iobase;
55	void __iomem *mmio_base;
56
57	bool exclusive_vectors;
58
59	struct wait_queue_head inout_wq;
60
61	void *data_buffer;
62	dma_addr_t data_buffer_base;
63	void *tx_buffer;
64	dma_addr_t tx_buffer_base;
65	void *notification_bitmap;
66	dma_addr_t notification_base;
67};
68
69static bool use_ppn64;
70
71bool vmci_use_ppn64(void)
72{
73	return use_ppn64;
74}
75
76/* vmci_dev singleton device and supporting data*/
77struct pci_dev *vmci_pdev;
78static struct vmci_guest_device *vmci_dev_g;
79static DEFINE_SPINLOCK(vmci_dev_spinlock);
80
81static atomic_t vmci_num_guest_devices = ATOMIC_INIT(0);
82
83bool vmci_guest_code_active(void)
84{
85	return atomic_read(&vmci_num_guest_devices) != 0;
86}
87
88u32 vmci_get_vm_context_id(void)
89{
90	if (vm_context_id == VMCI_INVALID_ID) {
91		struct vmci_datagram get_cid_msg;
92		get_cid_msg.dst =
93		    vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
94				     VMCI_GET_CONTEXT_ID);
95		get_cid_msg.src = VMCI_ANON_SRC_HANDLE;
96		get_cid_msg.payload_size = 0;
97		vm_context_id = vmci_send_datagram(&get_cid_msg);
98	}
99	return vm_context_id;
100}
101
102static unsigned int vmci_read_reg(struct vmci_guest_device *dev, u32 reg)
103{
104	if (dev->mmio_base != NULL)
105		return readl(dev->mmio_base + reg);
106	return ioread32(dev->iobase + reg);
107}
108
109static void vmci_write_reg(struct vmci_guest_device *dev, u32 val, u32 reg)
110{
111	if (dev->mmio_base != NULL)
112		writel(val, dev->mmio_base + reg);
113	else
114		iowrite32(val, dev->iobase + reg);
115}
116
117static void vmci_read_data(struct vmci_guest_device *vmci_dev,
118			   void *dest, size_t size)
119{
120	if (vmci_dev->mmio_base == NULL)
121		ioread8_rep(vmci_dev->iobase + VMCI_DATA_IN_ADDR,
122			    dest, size);
123	else {
124		/*
125		 * For DMA datagrams, the data_buffer will contain the header on the
126		 * first page, followed by the incoming datagram(s) on the following
127		 * pages. The header uses an S/G element immediately following the
128		 * header on the first page to point to the data area.
129		 */
130		struct vmci_data_in_out_header *buffer_header = vmci_dev->data_buffer;
131		struct vmci_sg_elem *sg_array = (struct vmci_sg_elem *)(buffer_header + 1);
132		size_t buffer_offset = dest - vmci_dev->data_buffer;
133
134		buffer_header->opcode = 1;
135		buffer_header->size = 1;
136		buffer_header->busy = 0;
137		sg_array[0].addr = vmci_dev->data_buffer_base + buffer_offset;
138		sg_array[0].size = size;
139
140		vmci_write_reg(vmci_dev, lower_32_bits(vmci_dev->data_buffer_base),
141			       VMCI_DATA_IN_LOW_ADDR);
142
143		wait_event(vmci_dev->inout_wq, buffer_header->busy == 1);
144	}
145}
146
147static int vmci_write_data(struct vmci_guest_device *dev,
148			   struct vmci_datagram *dg)
149{
150	int result;
151
152	if (dev->mmio_base != NULL) {
153		struct vmci_data_in_out_header *buffer_header = dev->tx_buffer;
154		u8 *dg_out_buffer = (u8 *)(buffer_header + 1);
155
156		if (VMCI_DG_SIZE(dg) > VMCI_MAX_DG_SIZE)
157			return VMCI_ERROR_INVALID_ARGS;
158
159		/*
160		 * Initialize send buffer with outgoing datagram
161		 * and set up header for inline data. Device will
162		 * not access buffer asynchronously - only after
163		 * the write to VMCI_DATA_OUT_LOW_ADDR.
164		 */
165		memcpy(dg_out_buffer, dg, VMCI_DG_SIZE(dg));
166		buffer_header->opcode = 0;
167		buffer_header->size = VMCI_DG_SIZE(dg);
168		buffer_header->busy = 1;
169
170		vmci_write_reg(dev, lower_32_bits(dev->tx_buffer_base),
171			       VMCI_DATA_OUT_LOW_ADDR);
172
173		/* Caller holds a spinlock, so cannot block. */
174		spin_until_cond(buffer_header->busy == 0);
175
176		result = vmci_read_reg(vmci_dev_g, VMCI_RESULT_LOW_ADDR);
177		if (result == VMCI_SUCCESS)
178			result = (int)buffer_header->result;
179	} else {
180		iowrite8_rep(dev->iobase + VMCI_DATA_OUT_ADDR,
181			     dg, VMCI_DG_SIZE(dg));
182		result = vmci_read_reg(vmci_dev_g, VMCI_RESULT_LOW_ADDR);
183	}
184
185	return result;
186}
187
188/*
189 * VM to hypervisor call mechanism. We use the standard VMware naming
190 * convention since shared code is calling this function as well.
191 */
192int vmci_send_datagram(struct vmci_datagram *dg)
193{
194	unsigned long flags;
195	int result;
196
197	/* Check args. */
198	if (dg == NULL)
199		return VMCI_ERROR_INVALID_ARGS;
200
201	/*
202	 * Need to acquire spinlock on the device because the datagram
203	 * data may be spread over multiple pages and the monitor may
204	 * interleave device user rpc calls from multiple
205	 * VCPUs. Acquiring the spinlock precludes that
206	 * possibility. Disabling interrupts to avoid incoming
207	 * datagrams during a "rep out" and possibly landing up in
208	 * this function.
209	 */
210	spin_lock_irqsave(&vmci_dev_spinlock, flags);
211
212	if (vmci_dev_g) {
213		vmci_write_data(vmci_dev_g, dg);
214		result = vmci_read_reg(vmci_dev_g, VMCI_RESULT_LOW_ADDR);
215	} else {
216		result = VMCI_ERROR_UNAVAILABLE;
217	}
218
219	spin_unlock_irqrestore(&vmci_dev_spinlock, flags);
220
221	return result;
222}
223EXPORT_SYMBOL_GPL(vmci_send_datagram);
224
225/*
226 * Gets called with the new context id if updated or resumed.
227 * Context id.
228 */
229static void vmci_guest_cid_update(u32 sub_id,
230				  const struct vmci_event_data *event_data,
231				  void *client_data)
232{
233	const struct vmci_event_payld_ctx *ev_payload =
234				vmci_event_data_const_payload(event_data);
235
236	if (sub_id != ctx_update_sub_id) {
237		pr_devel("Invalid subscriber (ID=0x%x)\n", sub_id);
238		return;
239	}
240
241	if (!event_data || ev_payload->context_id == VMCI_INVALID_ID) {
242		pr_devel("Invalid event data\n");
243		return;
244	}
245
246	pr_devel("Updating context from (ID=0x%x) to (ID=0x%x) on event (type=%d)\n",
247		 vm_context_id, ev_payload->context_id, event_data->event);
248
249	vm_context_id = ev_payload->context_id;
250}
251
252/*
253 * Verify that the host supports the hypercalls we need. If it does not,
254 * try to find fallback hypercalls and use those instead.  Returns 0 if
255 * required hypercalls (or fallback hypercalls) are supported by the host,
256 * an error code otherwise.
257 */
258static int vmci_check_host_caps(struct pci_dev *pdev)
259{
260	bool result;
261	struct vmci_resource_query_msg *msg;
262	u32 msg_size = sizeof(struct vmci_resource_query_hdr) +
263				VMCI_UTIL_NUM_RESOURCES * sizeof(u32);
264	struct vmci_datagram *check_msg;
265
266	check_msg = kzalloc(msg_size, GFP_KERNEL);
267	if (!check_msg) {
268		dev_err(&pdev->dev, "%s: Insufficient memory\n", __func__);
269		return -ENOMEM;
270	}
271
272	check_msg->dst = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID,
273					  VMCI_RESOURCES_QUERY);
274	check_msg->src = VMCI_ANON_SRC_HANDLE;
275	check_msg->payload_size = msg_size - VMCI_DG_HEADERSIZE;
276	msg = (struct vmci_resource_query_msg *)VMCI_DG_PAYLOAD(check_msg);
277
278	msg->num_resources = VMCI_UTIL_NUM_RESOURCES;
279	msg->resources[0] = VMCI_GET_CONTEXT_ID;
280
281	/* Checks that hyper calls are supported */
282	result = vmci_send_datagram(check_msg) == 0x01;
283	kfree(check_msg);
284
285	dev_dbg(&pdev->dev, "%s: Host capability check: %s\n",
286		__func__, result ? "PASSED" : "FAILED");
287
288	/* We need the vector. There are no fallbacks. */
289	return result ? 0 : -ENXIO;
290}
291
292/*
293 * Reads datagrams from the device and dispatches them. For IO port
294 * based access to the device, we always start reading datagrams into
295 * only the first page of the datagram buffer. If the datagrams don't
296 * fit into one page, we use the maximum datagram buffer size for the
297 * remainder of the invocation. This is a simple heuristic for not
298 * penalizing small datagrams. For DMA-based datagrams, we always
299 * use the maximum datagram buffer size, since there is no performance
300 * penalty for doing so.
301 *
302 * This function assumes that it has exclusive access to the data
303 * in register(s) for the duration of the call.
304 */
305static void vmci_dispatch_dgs(struct vmci_guest_device *vmci_dev)
306{
307	u8 *dg_in_buffer = vmci_dev->data_buffer;
308	struct vmci_datagram *dg;
309	size_t dg_in_buffer_size = VMCI_MAX_DG_SIZE;
310	size_t current_dg_in_buffer_size;
311	size_t remaining_bytes;
312	bool is_io_port = vmci_dev->mmio_base == NULL;
313
314	BUILD_BUG_ON(VMCI_MAX_DG_SIZE < PAGE_SIZE);
315
316	if (!is_io_port) {
317		/* For mmio, the first page is used for the header. */
318		dg_in_buffer += PAGE_SIZE;
319
320		/*
321		 * For DMA-based datagram operations, there is no performance
322		 * penalty for reading the maximum buffer size.
323		 */
324		current_dg_in_buffer_size = VMCI_MAX_DG_SIZE;
325	} else {
326		current_dg_in_buffer_size = PAGE_SIZE;
327	}
328	vmci_read_data(vmci_dev, dg_in_buffer, current_dg_in_buffer_size);
329	dg = (struct vmci_datagram *)dg_in_buffer;
330	remaining_bytes = current_dg_in_buffer_size;
331
332	/*
333	 * Read through the buffer until an invalid datagram header is
334	 * encountered. The exit condition for datagrams read through
335	 * VMCI_DATA_IN_ADDR is a bit more complicated, since a datagram
336	 * can start on any page boundary in the buffer.
337	 */
338	while (dg->dst.resource != VMCI_INVALID_ID ||
339	       (is_io_port && remaining_bytes > PAGE_SIZE)) {
340		unsigned dg_in_size;
341
342		/*
343		 * If using VMCI_DATA_IN_ADDR, skip to the next page
344		 * as a datagram can start on any page boundary.
345		 */
346		if (dg->dst.resource == VMCI_INVALID_ID) {
347			dg = (struct vmci_datagram *)roundup(
348				(uintptr_t)dg + 1, PAGE_SIZE);
349			remaining_bytes =
350				(size_t)(dg_in_buffer +
351					 current_dg_in_buffer_size -
352					 (u8 *)dg);
353			continue;
354		}
355
356		dg_in_size = VMCI_DG_SIZE_ALIGNED(dg);
357
358		if (dg_in_size <= dg_in_buffer_size) {
359			int result;
360
361			/*
362			 * If the remaining bytes in the datagram
363			 * buffer doesn't contain the complete
364			 * datagram, we first make sure we have enough
365			 * room for it and then we read the reminder
366			 * of the datagram and possibly any following
367			 * datagrams.
368			 */
369			if (dg_in_size > remaining_bytes) {
370				if (remaining_bytes !=
371				    current_dg_in_buffer_size) {
372
373					/*
374					 * We move the partial
375					 * datagram to the front and
376					 * read the reminder of the
377					 * datagram and possibly
378					 * following calls into the
379					 * following bytes.
380					 */
381					memmove(dg_in_buffer, dg_in_buffer +
382						current_dg_in_buffer_size -
383						remaining_bytes,
384						remaining_bytes);
385					dg = (struct vmci_datagram *)
386					    dg_in_buffer;
387				}
388
389				if (current_dg_in_buffer_size !=
390				    dg_in_buffer_size)
391					current_dg_in_buffer_size =
392					    dg_in_buffer_size;
393
394				vmci_read_data(vmci_dev,
395					       dg_in_buffer +
396						remaining_bytes,
397					       current_dg_in_buffer_size -
398						remaining_bytes);
399			}
400
401			/*
402			 * We special case event datagrams from the
403			 * hypervisor.
404			 */
405			if (dg->src.context == VMCI_HYPERVISOR_CONTEXT_ID &&
406			    dg->dst.resource == VMCI_EVENT_HANDLER) {
407				result = vmci_event_dispatch(dg);
408			} else {
409				result = vmci_datagram_invoke_guest_handler(dg);
410			}
411			if (result < VMCI_SUCCESS)
412				dev_dbg(vmci_dev->dev,
413					"Datagram with resource (ID=0x%x) failed (err=%d)\n",
414					 dg->dst.resource, result);
415
416			/* On to the next datagram. */
417			dg = (struct vmci_datagram *)((u8 *)dg +
418						      dg_in_size);
419		} else {
420			size_t bytes_to_skip;
421
422			/*
423			 * Datagram doesn't fit in datagram buffer of maximal
424			 * size. We drop it.
425			 */
426			dev_dbg(vmci_dev->dev,
427				"Failed to receive datagram (size=%u bytes)\n",
428				 dg_in_size);
429
430			bytes_to_skip = dg_in_size - remaining_bytes;
431			if (current_dg_in_buffer_size != dg_in_buffer_size)
432				current_dg_in_buffer_size = dg_in_buffer_size;
433
434			for (;;) {
435				vmci_read_data(vmci_dev, dg_in_buffer,
436					       current_dg_in_buffer_size);
437				if (bytes_to_skip <= current_dg_in_buffer_size)
438					break;
439
440				bytes_to_skip -= current_dg_in_buffer_size;
441			}
442			dg = (struct vmci_datagram *)(dg_in_buffer +
443						      bytes_to_skip);
444		}
445
446		remaining_bytes =
447		    (size_t) (dg_in_buffer + current_dg_in_buffer_size -
448			      (u8 *)dg);
449
450		if (remaining_bytes < VMCI_DG_HEADERSIZE) {
451			/* Get the next batch of datagrams. */
452
453			vmci_read_data(vmci_dev, dg_in_buffer,
454				    current_dg_in_buffer_size);
455			dg = (struct vmci_datagram *)dg_in_buffer;
456			remaining_bytes = current_dg_in_buffer_size;
457		}
458	}
459}
460
461/*
462 * Scans the notification bitmap for raised flags, clears them
463 * and handles the notifications.
464 */
465static void vmci_process_bitmap(struct vmci_guest_device *dev)
466{
467	if (!dev->notification_bitmap) {
468		dev_dbg(dev->dev, "No bitmap present in %s\n", __func__);
469		return;
470	}
471
472	vmci_dbell_scan_notification_entries(dev->notification_bitmap);
473}
474
475/*
476 * Interrupt handler for legacy or MSI interrupt, or for first MSI-X
477 * interrupt (vector VMCI_INTR_DATAGRAM).
478 */
479static irqreturn_t vmci_interrupt(int irq, void *_dev)
480{
481	struct vmci_guest_device *dev = _dev;
482
483	/*
484	 * If we are using MSI-X with exclusive vectors then we simply call
485	 * vmci_dispatch_dgs(), since we know the interrupt was meant for us.
486	 * Otherwise we must read the ICR to determine what to do.
487	 */
488
489	if (dev->exclusive_vectors) {
490		vmci_dispatch_dgs(dev);
491	} else {
492		unsigned int icr;
493
494		/* Acknowledge interrupt and determine what needs doing. */
495		icr = vmci_read_reg(dev, VMCI_ICR_ADDR);
496		if (icr == 0 || icr == ~0)
497			return IRQ_NONE;
498
499		if (icr & VMCI_ICR_DATAGRAM) {
500			vmci_dispatch_dgs(dev);
501			icr &= ~VMCI_ICR_DATAGRAM;
502		}
503
504		if (icr & VMCI_ICR_NOTIFICATION) {
505			vmci_process_bitmap(dev);
506			icr &= ~VMCI_ICR_NOTIFICATION;
507		}
508
509
510		if (icr & VMCI_ICR_DMA_DATAGRAM) {
511			wake_up_all(&dev->inout_wq);
512			icr &= ~VMCI_ICR_DMA_DATAGRAM;
513		}
514
515		if (icr != 0)
516			dev_warn(dev->dev,
517				 "Ignoring unknown interrupt cause (%d)\n",
518				 icr);
519	}
520
521	return IRQ_HANDLED;
522}
523
524/*
525 * Interrupt handler for MSI-X interrupt vector VMCI_INTR_NOTIFICATION,
526 * which is for the notification bitmap.  Will only get called if we are
527 * using MSI-X with exclusive vectors.
528 */
529static irqreturn_t vmci_interrupt_bm(int irq, void *_dev)
530{
531	struct vmci_guest_device *dev = _dev;
532
533	/* For MSI-X we can just assume it was meant for us. */
534	vmci_process_bitmap(dev);
535
536	return IRQ_HANDLED;
537}
538
539/*
540 * Interrupt handler for MSI-X interrupt vector VMCI_INTR_DMA_DATAGRAM,
541 * which is for the completion of a DMA datagram send or receive operation.
542 * Will only get called if we are using MSI-X with exclusive vectors.
543 */
544static irqreturn_t vmci_interrupt_dma_datagram(int irq, void *_dev)
545{
546	struct vmci_guest_device *dev = _dev;
547
548	wake_up_all(&dev->inout_wq);
549
550	return IRQ_HANDLED;
551}
552
553static void vmci_free_dg_buffers(struct vmci_guest_device *vmci_dev)
554{
555	if (vmci_dev->mmio_base != NULL) {
556		if (vmci_dev->tx_buffer != NULL)
557			dma_free_coherent(vmci_dev->dev,
558					  VMCI_DMA_DG_BUFFER_SIZE,
559					  vmci_dev->tx_buffer,
560					  vmci_dev->tx_buffer_base);
561		if (vmci_dev->data_buffer != NULL)
562			dma_free_coherent(vmci_dev->dev,
563					  VMCI_DMA_DG_BUFFER_SIZE,
564					  vmci_dev->data_buffer,
565					  vmci_dev->data_buffer_base);
566	} else {
567		vfree(vmci_dev->data_buffer);
568	}
569}
570
571/*
572 * Most of the initialization at module load time is done here.
573 */
574static int vmci_guest_probe_device(struct pci_dev *pdev,
575				   const struct pci_device_id *id)
576{
577	struct vmci_guest_device *vmci_dev;
578	void __iomem *iobase = NULL;
579	void __iomem *mmio_base = NULL;
580	unsigned int num_irq_vectors;
581	unsigned int capabilities;
582	unsigned int caps_in_use;
583	unsigned long cmd;
584	int vmci_err;
585	int error;
586
587	dev_dbg(&pdev->dev, "Probing for vmci/PCI guest device\n");
588
589	error = pcim_enable_device(pdev);
590	if (error) {
591		dev_err(&pdev->dev,
592			"Failed to enable VMCI device: %d\n", error);
593		return error;
594	}
595
596	/*
597	 * The VMCI device with mmio access to registers requests 256KB
598	 * for BAR1. If present, driver will use new VMCI device
599	 * functionality for register access and datagram send/recv.
600	 */
601
602	if (pci_resource_len(pdev, 1) == VMCI_WITH_MMIO_ACCESS_BAR_SIZE) {
603		dev_info(&pdev->dev, "MMIO register access is available\n");
604		mmio_base = pci_iomap_range(pdev, 1, VMCI_MMIO_ACCESS_OFFSET,
605					    VMCI_MMIO_ACCESS_SIZE);
606		/* If the map fails, we fall back to IOIO access. */
607		if (!mmio_base)
608			dev_warn(&pdev->dev, "Failed to map MMIO register access\n");
609	}
610
611	if (!mmio_base) {
612		if (IS_ENABLED(CONFIG_ARM64)) {
613			dev_err(&pdev->dev, "MMIO base is invalid\n");
614			return -ENXIO;
615		}
616		error = pcim_iomap_regions(pdev, BIT(0), KBUILD_MODNAME);
617		if (error) {
618			dev_err(&pdev->dev, "Failed to reserve/map IO regions\n");
619			return error;
620		}
621		iobase = pcim_iomap_table(pdev)[0];
622	}
623
624	vmci_dev = devm_kzalloc(&pdev->dev, sizeof(*vmci_dev), GFP_KERNEL);
625	if (!vmci_dev) {
626		dev_err(&pdev->dev,
627			"Can't allocate memory for VMCI device\n");
628		error = -ENOMEM;
629		goto err_unmap_mmio_base;
630	}
631
632	vmci_dev->dev = &pdev->dev;
633	vmci_dev->exclusive_vectors = false;
634	vmci_dev->iobase = iobase;
635	vmci_dev->mmio_base = mmio_base;
636
637	init_waitqueue_head(&vmci_dev->inout_wq);
638
639	if (mmio_base != NULL) {
640		vmci_dev->tx_buffer = dma_alloc_coherent(&pdev->dev, VMCI_DMA_DG_BUFFER_SIZE,
641							 &vmci_dev->tx_buffer_base,
642							 GFP_KERNEL);
643		if (!vmci_dev->tx_buffer) {
644			dev_err(&pdev->dev,
645				"Can't allocate memory for datagram tx buffer\n");
646			error = -ENOMEM;
647			goto err_unmap_mmio_base;
648		}
649
650		vmci_dev->data_buffer = dma_alloc_coherent(&pdev->dev, VMCI_DMA_DG_BUFFER_SIZE,
651							   &vmci_dev->data_buffer_base,
652							   GFP_KERNEL);
653	} else {
654		vmci_dev->data_buffer = vmalloc(VMCI_MAX_DG_SIZE);
655	}
656	if (!vmci_dev->data_buffer) {
657		dev_err(&pdev->dev,
658			"Can't allocate memory for datagram buffer\n");
659		error = -ENOMEM;
660		goto err_free_data_buffers;
661	}
662
663	pci_set_master(pdev);	/* To enable queue_pair functionality. */
664
665	/*
666	 * Verify that the VMCI Device supports the capabilities that
667	 * we need. If the device is missing capabilities that we would
668	 * like to use, check for fallback capabilities and use those
669	 * instead (so we can run a new VM on old hosts). Fail the load if
670	 * a required capability is missing and there is no fallback.
671	 *
672	 * Right now, we need datagrams. There are no fallbacks.
673	 */
674	capabilities = vmci_read_reg(vmci_dev, VMCI_CAPS_ADDR);
675	if (!(capabilities & VMCI_CAPS_DATAGRAM)) {
676		dev_err(&pdev->dev, "Device does not support datagrams\n");
677		error = -ENXIO;
678		goto err_free_data_buffers;
679	}
680	caps_in_use = VMCI_CAPS_DATAGRAM;
681
682	/*
683	 * Use 64-bit PPNs if the device supports.
684	 *
685	 * There is no check for the return value of dma_set_mask_and_coherent
686	 * since this driver can handle the default mask values if
687	 * dma_set_mask_and_coherent fails.
688	 */
689	if (capabilities & VMCI_CAPS_PPN64) {
690		dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
691		use_ppn64 = true;
692		caps_in_use |= VMCI_CAPS_PPN64;
693	} else {
694		dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(44));
695		use_ppn64 = false;
696	}
697
698	/*
699	 * If the hardware supports notifications, we will use that as
700	 * well.
701	 */
702	if (capabilities & VMCI_CAPS_NOTIFICATIONS) {
703		vmci_dev->notification_bitmap = dma_alloc_coherent(
704			&pdev->dev, PAGE_SIZE, &vmci_dev->notification_base,
705			GFP_KERNEL);
706		if (!vmci_dev->notification_bitmap)
707			dev_warn(&pdev->dev,
708				 "Unable to allocate notification bitmap\n");
709		else
710			caps_in_use |= VMCI_CAPS_NOTIFICATIONS;
711	}
712
713	if (mmio_base != NULL) {
714		if (capabilities & VMCI_CAPS_DMA_DATAGRAM) {
715			caps_in_use |= VMCI_CAPS_DMA_DATAGRAM;
716		} else {
717			dev_err(&pdev->dev,
718				"Missing capability: VMCI_CAPS_DMA_DATAGRAM\n");
719			error = -ENXIO;
720			goto err_free_notification_bitmap;
721		}
722	}
723
724	dev_info(&pdev->dev, "Using capabilities 0x%x\n", caps_in_use);
725
726	/* Let the host know which capabilities we intend to use. */
727	vmci_write_reg(vmci_dev, caps_in_use, VMCI_CAPS_ADDR);
728
729	if (caps_in_use & VMCI_CAPS_DMA_DATAGRAM) {
730		/* Let the device know the size for pages passed down. */
731		vmci_write_reg(vmci_dev, PAGE_SHIFT, VMCI_GUEST_PAGE_SHIFT);
732
733		/* Configure the high order parts of the data in/out buffers. */
734		vmci_write_reg(vmci_dev, upper_32_bits(vmci_dev->data_buffer_base),
735			       VMCI_DATA_IN_HIGH_ADDR);
736		vmci_write_reg(vmci_dev, upper_32_bits(vmci_dev->tx_buffer_base),
737			       VMCI_DATA_OUT_HIGH_ADDR);
738	}
739
740	/* Set up global device so that we can start sending datagrams */
741	spin_lock_irq(&vmci_dev_spinlock);
742	vmci_dev_g = vmci_dev;
743	vmci_pdev = pdev;
744	spin_unlock_irq(&vmci_dev_spinlock);
745
746	/*
747	 * Register notification bitmap with device if that capability is
748	 * used.
749	 */
750	if (caps_in_use & VMCI_CAPS_NOTIFICATIONS) {
751		unsigned long bitmap_ppn =
752			vmci_dev->notification_base >> PAGE_SHIFT;
753		if (!vmci_dbell_register_notification_bitmap(bitmap_ppn)) {
754			dev_warn(&pdev->dev,
755				 "VMCI device unable to register notification bitmap with PPN 0x%lx\n",
756				 bitmap_ppn);
757			error = -ENXIO;
758			goto err_remove_vmci_dev_g;
759		}
760	}
761
762	/* Check host capabilities. */
763	error = vmci_check_host_caps(pdev);
764	if (error)
765		goto err_remove_vmci_dev_g;
766
767	/* Enable device. */
768
769	/*
770	 * We subscribe to the VMCI_EVENT_CTX_ID_UPDATE here so we can
771	 * update the internal context id when needed.
772	 */
773	vmci_err = vmci_event_subscribe(VMCI_EVENT_CTX_ID_UPDATE,
774					vmci_guest_cid_update, NULL,
775					&ctx_update_sub_id);
776	if (vmci_err < VMCI_SUCCESS)
777		dev_warn(&pdev->dev,
778			 "Failed to subscribe to event (type=%d): %d\n",
779			 VMCI_EVENT_CTX_ID_UPDATE, vmci_err);
780
781	/*
782	 * Enable interrupts.  Try MSI-X first, then MSI, and then fallback on
783	 * legacy interrupts.
784	 */
785	if (vmci_dev->mmio_base != NULL)
786		num_irq_vectors = VMCI_MAX_INTRS;
787	else
788		num_irq_vectors = VMCI_MAX_INTRS_NOTIFICATION;
789	error = pci_alloc_irq_vectors(pdev, num_irq_vectors, num_irq_vectors,
790				      PCI_IRQ_MSIX);
791	if (error < 0) {
792		error = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
793		if (error < 0)
794			goto err_unsubscribe_event;
795	} else {
796		vmci_dev->exclusive_vectors = true;
797	}
798
799	/*
800	 * Request IRQ for legacy or MSI interrupts, or for first
801	 * MSI-X vector.
802	 */
803	error = request_threaded_irq(pci_irq_vector(pdev, 0), NULL,
804				     vmci_interrupt, IRQF_SHARED,
805				     KBUILD_MODNAME, vmci_dev);
806	if (error) {
807		dev_err(&pdev->dev, "Irq %u in use: %d\n",
808			pci_irq_vector(pdev, 0), error);
809		goto err_disable_msi;
810	}
811
812	/*
813	 * For MSI-X with exclusive vectors we need to request an
814	 * interrupt for each vector so that we get a separate
815	 * interrupt handler routine.  This allows us to distinguish
816	 * between the vectors.
817	 */
818	if (vmci_dev->exclusive_vectors) {
819		error = request_threaded_irq(pci_irq_vector(pdev, 1), NULL,
820					     vmci_interrupt_bm, 0,
821					     KBUILD_MODNAME, vmci_dev);
822		if (error) {
823			dev_err(&pdev->dev,
824				"Failed to allocate irq %u: %d\n",
825				pci_irq_vector(pdev, 1), error);
826			goto err_free_irq;
827		}
828		if (caps_in_use & VMCI_CAPS_DMA_DATAGRAM) {
829			error = request_threaded_irq(pci_irq_vector(pdev, 2),
830						     NULL,
831						    vmci_interrupt_dma_datagram,
832						     0, KBUILD_MODNAME,
833						     vmci_dev);
834			if (error) {
835				dev_err(&pdev->dev,
836					"Failed to allocate irq %u: %d\n",
837					pci_irq_vector(pdev, 2), error);
838				goto err_free_bm_irq;
839			}
840		}
841	}
842
843	dev_dbg(&pdev->dev, "Registered device\n");
844
845	atomic_inc(&vmci_num_guest_devices);
846
847	/* Enable specific interrupt bits. */
848	cmd = VMCI_IMR_DATAGRAM;
849	if (caps_in_use & VMCI_CAPS_NOTIFICATIONS)
850		cmd |= VMCI_IMR_NOTIFICATION;
851	if (caps_in_use & VMCI_CAPS_DMA_DATAGRAM)
852		cmd |= VMCI_IMR_DMA_DATAGRAM;
853	vmci_write_reg(vmci_dev, cmd, VMCI_IMR_ADDR);
854
855	/* Enable interrupts. */
856	vmci_write_reg(vmci_dev, VMCI_CONTROL_INT_ENABLE, VMCI_CONTROL_ADDR);
857
858	pci_set_drvdata(pdev, vmci_dev);
859
860	vmci_call_vsock_callback(false);
861	return 0;
862
863err_free_bm_irq:
864	if (vmci_dev->exclusive_vectors)
865		free_irq(pci_irq_vector(pdev, 1), vmci_dev);
866
867err_free_irq:
868	free_irq(pci_irq_vector(pdev, 0), vmci_dev);
869
870err_disable_msi:
871	pci_free_irq_vectors(pdev);
872
873err_unsubscribe_event:
874	vmci_err = vmci_event_unsubscribe(ctx_update_sub_id);
875	if (vmci_err < VMCI_SUCCESS)
876		dev_warn(&pdev->dev,
877			 "Failed to unsubscribe from event (type=%d) with subscriber (ID=0x%x): %d\n",
878			 VMCI_EVENT_CTX_ID_UPDATE, ctx_update_sub_id, vmci_err);
879
880err_remove_vmci_dev_g:
881	spin_lock_irq(&vmci_dev_spinlock);
882	vmci_pdev = NULL;
883	vmci_dev_g = NULL;
884	spin_unlock_irq(&vmci_dev_spinlock);
885
886err_free_notification_bitmap:
887	if (vmci_dev->notification_bitmap) {
888		vmci_write_reg(vmci_dev, VMCI_CONTROL_RESET, VMCI_CONTROL_ADDR);
889		dma_free_coherent(&pdev->dev, PAGE_SIZE,
890				  vmci_dev->notification_bitmap,
891				  vmci_dev->notification_base);
892	}
893
894err_free_data_buffers:
895	vmci_free_dg_buffers(vmci_dev);
896
897err_unmap_mmio_base:
898	if (mmio_base != NULL)
899		pci_iounmap(pdev, mmio_base);
900
901	/* The rest are managed resources and will be freed by PCI core */
902	return error;
903}
904
905static void vmci_guest_remove_device(struct pci_dev *pdev)
906{
907	struct vmci_guest_device *vmci_dev = pci_get_drvdata(pdev);
908	int vmci_err;
909
910	dev_dbg(&pdev->dev, "Removing device\n");
911
912	atomic_dec(&vmci_num_guest_devices);
913
914	vmci_qp_guest_endpoints_exit();
915
916	vmci_err = vmci_event_unsubscribe(ctx_update_sub_id);
917	if (vmci_err < VMCI_SUCCESS)
918		dev_warn(&pdev->dev,
919			 "Failed to unsubscribe from event (type=%d) with subscriber (ID=0x%x): %d\n",
920			 VMCI_EVENT_CTX_ID_UPDATE, ctx_update_sub_id, vmci_err);
921
922	spin_lock_irq(&vmci_dev_spinlock);
923	vmci_dev_g = NULL;
924	vmci_pdev = NULL;
925	spin_unlock_irq(&vmci_dev_spinlock);
926
927	dev_dbg(&pdev->dev, "Resetting vmci device\n");
928	vmci_write_reg(vmci_dev, VMCI_CONTROL_RESET, VMCI_CONTROL_ADDR);
929
930	/*
931	 * Free IRQ and then disable MSI/MSI-X as appropriate.  For
932	 * MSI-X, we might have multiple vectors, each with their own
933	 * IRQ, which we must free too.
934	 */
935	if (vmci_dev->exclusive_vectors) {
936		free_irq(pci_irq_vector(pdev, 1), vmci_dev);
937		if (vmci_dev->mmio_base != NULL)
938			free_irq(pci_irq_vector(pdev, 2), vmci_dev);
939	}
940	free_irq(pci_irq_vector(pdev, 0), vmci_dev);
941	pci_free_irq_vectors(pdev);
942
943	if (vmci_dev->notification_bitmap) {
944		/*
945		 * The device reset above cleared the bitmap state of the
946		 * device, so we can safely free it here.
947		 */
948
949		dma_free_coherent(&pdev->dev, PAGE_SIZE,
950				  vmci_dev->notification_bitmap,
951				  vmci_dev->notification_base);
952	}
953
954	vmci_free_dg_buffers(vmci_dev);
955
956	if (vmci_dev->mmio_base != NULL)
957		pci_iounmap(pdev, vmci_dev->mmio_base);
958
959	/* The rest are managed resources and will be freed by PCI core */
960}
961
962static const struct pci_device_id vmci_ids[] = {
963	{ PCI_DEVICE(PCI_VENDOR_ID_VMWARE, PCI_DEVICE_ID_VMWARE_VMCI), },
964	{ 0 },
965};
966MODULE_DEVICE_TABLE(pci, vmci_ids);
967
968static struct pci_driver vmci_guest_driver = {
969	.name		= KBUILD_MODNAME,
970	.id_table	= vmci_ids,
971	.probe		= vmci_guest_probe_device,
972	.remove		= vmci_guest_remove_device,
973};
974
975int __init vmci_guest_init(void)
976{
977	return pci_register_driver(&vmci_guest_driver);
978}
979
980void __exit vmci_guest_exit(void)
981{
982	pci_unregister_driver(&vmci_guest_driver);
983}
984