xref: /linux/drivers/misc/ibmvmc.c (revision c16ce856e422e73a54c41131e0332de1afe09b8b)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * IBM Power Systems Virtual Management Channel Support.
4  *
5  * Copyright (c) 2004, 2018 IBM Corp.
6  *   Dave Engebretsen engebret@us.ibm.com
7  *   Steven Royer seroyer@linux.vnet.ibm.com
8  *   Adam Reznechek adreznec@linux.vnet.ibm.com
9  *   Bryant G. Ly <bryantly@linux.vnet.ibm.com>
10  */
11 
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/kthread.h>
15 #include <linux/major.h>
16 #include <linux/string.h>
17 #include <linux/fcntl.h>
18 #include <linux/slab.h>
19 #include <linux/poll.h>
20 #include <linux/init.h>
21 #include <linux/fs.h>
22 #include <linux/interrupt.h>
23 #include <linux/spinlock.h>
24 #include <linux/percpu.h>
25 #include <linux/delay.h>
26 #include <linux/uaccess.h>
27 #include <linux/io.h>
28 #include <linux/miscdevice.h>
29 #include <linux/sched/signal.h>
30 
31 #include <asm/byteorder.h>
32 #include <asm/irq.h>
33 #include <asm/vio.h>
34 
35 #include "ibmvmc.h"
36 
37 #define IBMVMC_DRIVER_VERSION "1.0"
38 
39 /*
40  * Static global variables
41  */
42 static DECLARE_WAIT_QUEUE_HEAD(ibmvmc_read_wait);
43 
44 static const char ibmvmc_driver_name[] = "ibmvmc";
45 
46 static struct ibmvmc_struct ibmvmc;
47 static struct ibmvmc_hmc hmcs[MAX_HMCS];
48 static struct crq_server_adapter ibmvmc_adapter;
49 
50 static int ibmvmc_max_buf_pool_size = DEFAULT_BUF_POOL_SIZE;
51 static int ibmvmc_max_hmcs = DEFAULT_HMCS;
52 static int ibmvmc_max_mtu = DEFAULT_MTU;
53 
54 static inline long h_copy_rdma(s64 length, u64 sliobn, u64 slioba,
55 			       u64 dliobn, u64 dlioba)
56 {
57 	long rc = 0;
58 
59 	/* Ensure all writes to source memory are visible before hcall */
60 	dma_wmb();
61 	pr_debug("ibmvmc: h_copy_rdma(0x%llx, 0x%llx, 0x%llx, 0x%llx, 0x%llx\n",
62 		 length, sliobn, slioba, dliobn, dlioba);
63 	rc = plpar_hcall_norets(H_COPY_RDMA, length, sliobn, slioba,
64 				dliobn, dlioba);
65 	pr_debug("ibmvmc: h_copy_rdma rc = 0x%lx\n", rc);
66 
67 	return rc;
68 }
69 
70 static inline void h_free_crq(uint32_t unit_address)
71 {
72 	long rc = 0;
73 
74 	do {
75 		if (H_IS_LONG_BUSY(rc))
76 			msleep(get_longbusy_msecs(rc));
77 
78 		rc = plpar_hcall_norets(H_FREE_CRQ, unit_address);
79 	} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
80 }
81 
82 /**
83  * h_request_vmc: - request a hypervisor virtual management channel device
84  * @vmc_index: drc index of the vmc device created
85  *
86  * Requests the hypervisor create a new virtual management channel device,
87  * allowing this partition to send hypervisor virtualization control
88  * commands.
89  *
90  * Return:
91  *	0 - Success
92  *	Non-zero - Failure
93  */
94 static inline long h_request_vmc(u32 *vmc_index)
95 {
96 	long rc = 0;
97 	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
98 
99 	do {
100 		if (H_IS_LONG_BUSY(rc))
101 			msleep(get_longbusy_msecs(rc));
102 
103 		/* Call to request the VMC device from phyp */
104 		rc = plpar_hcall(H_REQUEST_VMC, retbuf);
105 		pr_debug("ibmvmc: %s rc = 0x%lx\n", __func__, rc);
106 		*vmc_index = retbuf[0];
107 	} while ((rc == H_BUSY) || (H_IS_LONG_BUSY(rc)));
108 
109 	return rc;
110 }
111 
112 /* routines for managing a command/response queue */
113 /**
114  * ibmvmc_handle_event: - Interrupt handler for crq events
115  * @irq:        number of irq to handle, not used
116  * @dev_instance: crq_server_adapter that received interrupt
117  *
118  * Disables interrupts and schedules ibmvmc_task
119  *
120  * Always returns IRQ_HANDLED
121  */
122 static irqreturn_t ibmvmc_handle_event(int irq, void *dev_instance)
123 {
124 	struct crq_server_adapter *adapter =
125 		(struct crq_server_adapter *)dev_instance;
126 
127 	vio_disable_interrupts(to_vio_dev(adapter->dev));
128 	tasklet_schedule(&adapter->work_task);
129 
130 	return IRQ_HANDLED;
131 }
132 
133 /**
134  * ibmvmc_release_crq_queue - Release CRQ Queue
135  *
136  * @adapter:	crq_server_adapter struct
137  *
138  * Return:
139  *	0 - Success
140  *	Non-Zero - Failure
141  */
142 static void ibmvmc_release_crq_queue(struct crq_server_adapter *adapter)
143 {
144 	struct vio_dev *vdev = to_vio_dev(adapter->dev);
145 	struct crq_queue *queue = &adapter->queue;
146 
147 	free_irq(vdev->irq, (void *)adapter);
148 	tasklet_kill(&adapter->work_task);
149 
150 	if (adapter->reset_task)
151 		kthread_stop(adapter->reset_task);
152 
153 	h_free_crq(vdev->unit_address);
154 	dma_unmap_single(adapter->dev,
155 			 queue->msg_token,
156 			 queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
157 	free_page((unsigned long)queue->msgs);
158 }
159 
160 /**
161  * ibmvmc_reset_crq_queue - Reset CRQ Queue
162  *
163  * @adapter:	crq_server_adapter struct
164  *
165  * This function calls h_free_crq and then calls H_REG_CRQ and does all the
166  * bookkeeping to get us back to where we can communicate.
167  *
168  * Return:
169  *	0 - Success
170  *	Non-Zero - Failure
171  */
172 static int ibmvmc_reset_crq_queue(struct crq_server_adapter *adapter)
173 {
174 	struct vio_dev *vdev = to_vio_dev(adapter->dev);
175 	struct crq_queue *queue = &adapter->queue;
176 	int rc = 0;
177 
178 	/* Close the CRQ */
179 	h_free_crq(vdev->unit_address);
180 
181 	/* Clean out the queue */
182 	memset(queue->msgs, 0x00, PAGE_SIZE);
183 	queue->cur = 0;
184 
185 	/* And re-open it again */
186 	rc = plpar_hcall_norets(H_REG_CRQ,
187 				vdev->unit_address,
188 				queue->msg_token, PAGE_SIZE);
189 	if (rc == 2)
190 		/* Adapter is good, but other end is not ready */
191 		dev_warn(adapter->dev, "Partner adapter not ready\n");
192 	else if (rc != 0)
193 		dev_err(adapter->dev, "couldn't register crq--rc 0x%x\n", rc);
194 
195 	return rc;
196 }
197 
198 /**
199  * crq_queue_next_crq: - Returns the next entry in message queue
200  * @queue:      crq_queue to use
201  *
202  * Returns pointer to next entry in queue, or NULL if there are no new
203  * entried in the CRQ.
204  */
205 static struct ibmvmc_crq_msg *crq_queue_next_crq(struct crq_queue *queue)
206 {
207 	struct ibmvmc_crq_msg *crq;
208 	unsigned long flags;
209 
210 	spin_lock_irqsave(&queue->lock, flags);
211 	crq = &queue->msgs[queue->cur];
212 	if (crq->valid & 0x80) {
213 		if (++queue->cur == queue->size)
214 			queue->cur = 0;
215 
216 		/* Ensure the read of the valid bit occurs before reading any
217 		 * other bits of the CRQ entry
218 		 */
219 		dma_rmb();
220 	} else {
221 		crq = NULL;
222 	}
223 
224 	spin_unlock_irqrestore(&queue->lock, flags);
225 
226 	return crq;
227 }
228 
229 /**
230  * ibmvmc_send_crq - Send CRQ
231  *
232  * @adapter:	crq_server_adapter struct
233  * @word1:	Word1 Data field
234  * @word2:	Word2 Data field
235  *
236  * Return:
237  *	0 - Success
238  *	Non-Zero - Failure
239  */
240 static long ibmvmc_send_crq(struct crq_server_adapter *adapter,
241 			    u64 word1, u64 word2)
242 {
243 	struct vio_dev *vdev = to_vio_dev(adapter->dev);
244 	long rc = 0;
245 
246 	dev_dbg(adapter->dev, "(0x%x, 0x%016llx, 0x%016llx)\n",
247 		vdev->unit_address, word1, word2);
248 
249 	/*
250 	 * Ensure the command buffer is flushed to memory before handing it
251 	 * over to the other side to prevent it from fetching any stale data.
252 	 */
253 	dma_wmb();
254 	rc = plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
255 	dev_dbg(adapter->dev, "rc = 0x%lx\n", rc);
256 
257 	return rc;
258 }
259 
260 /**
261  * alloc_dma_buffer - Create DMA Buffer
262  *
263  * @vdev:	vio_dev struct
264  * @size:	Size field
265  * @dma_handle:	DMA address field
266  *
267  * Allocates memory for the command queue and maps remote memory into an
268  * ioba.
269  *
270  * Returns a pointer to the buffer
271  */
272 static void *alloc_dma_buffer(struct vio_dev *vdev, size_t size,
273 			      dma_addr_t *dma_handle)
274 {
275 	/* allocate memory */
276 	void *buffer = kzalloc(size, GFP_ATOMIC);
277 
278 	if (!buffer) {
279 		*dma_handle = 0;
280 		return NULL;
281 	}
282 
283 	/* DMA map */
284 	*dma_handle = dma_map_single(&vdev->dev, buffer, size,
285 				     DMA_BIDIRECTIONAL);
286 
287 	if (dma_mapping_error(&vdev->dev, *dma_handle)) {
288 		*dma_handle = 0;
289 		kfree_sensitive(buffer);
290 		return NULL;
291 	}
292 
293 	return buffer;
294 }
295 
296 /**
297  * free_dma_buffer - Free DMA Buffer
298  *
299  * @vdev:	vio_dev struct
300  * @size:	Size field
301  * @vaddr:	Address field
302  * @dma_handle:	DMA address field
303  *
304  * Releases memory for a command queue and unmaps mapped remote memory.
305  */
306 static void free_dma_buffer(struct vio_dev *vdev, size_t size, void *vaddr,
307 			    dma_addr_t dma_handle)
308 {
309 	/* DMA unmap */
310 	dma_unmap_single(&vdev->dev, dma_handle, size, DMA_BIDIRECTIONAL);
311 
312 	/* deallocate memory */
313 	kfree_sensitive(vaddr);
314 }
315 
316 /**
317  * ibmvmc_get_valid_hmc_buffer - Retrieve Valid HMC Buffer
318  *
319  * @hmc_index:	HMC Index Field
320  *
321  * Return:
322  *	Pointer to ibmvmc_buffer
323  */
324 static struct ibmvmc_buffer *ibmvmc_get_valid_hmc_buffer(u8 hmc_index)
325 {
326 	struct ibmvmc_buffer *buffer;
327 	struct ibmvmc_buffer *ret_buf = NULL;
328 	unsigned long i;
329 
330 	if (hmc_index > ibmvmc.max_hmc_index)
331 		return NULL;
332 
333 	buffer = hmcs[hmc_index].buffer;
334 
335 	for (i = 0; i < ibmvmc_max_buf_pool_size; i++) {
336 		if (buffer[i].valid && buffer[i].free &&
337 		    buffer[i].owner == VMC_BUF_OWNER_ALPHA) {
338 			buffer[i].free = 0;
339 			ret_buf = &buffer[i];
340 			break;
341 		}
342 	}
343 
344 	return ret_buf;
345 }
346 
347 /**
348  * ibmvmc_get_free_hmc_buffer - Get Free HMC Buffer
349  *
350  * @adapter:	crq_server_adapter struct
351  * @hmc_index:	Hmc Index field
352  *
353  * Return:
354  *	Pointer to ibmvmc_buffer
355  */
356 static struct ibmvmc_buffer *ibmvmc_get_free_hmc_buffer(struct crq_server_adapter *adapter,
357 							u8 hmc_index)
358 {
359 	struct ibmvmc_buffer *buffer;
360 	struct ibmvmc_buffer *ret_buf = NULL;
361 	unsigned long i;
362 
363 	if (hmc_index > ibmvmc.max_hmc_index) {
364 		dev_info(adapter->dev, "get_free_hmc_buffer: invalid hmc_index=0x%x\n",
365 			 hmc_index);
366 		return NULL;
367 	}
368 
369 	buffer = hmcs[hmc_index].buffer;
370 
371 	for (i = 0; i < ibmvmc_max_buf_pool_size; i++) {
372 		if (buffer[i].free &&
373 		    buffer[i].owner == VMC_BUF_OWNER_ALPHA) {
374 			buffer[i].free = 0;
375 			ret_buf = &buffer[i];
376 			break;
377 		}
378 	}
379 
380 	return ret_buf;
381 }
382 
383 /**
384  * ibmvmc_free_hmc_buffer - Free an HMC Buffer
385  *
386  * @hmc:	ibmvmc_hmc struct
387  * @buffer:	ibmvmc_buffer struct
388  *
389  */
390 static void ibmvmc_free_hmc_buffer(struct ibmvmc_hmc *hmc,
391 				   struct ibmvmc_buffer *buffer)
392 {
393 	unsigned long flags;
394 
395 	spin_lock_irqsave(&hmc->lock, flags);
396 	buffer->free = 1;
397 	spin_unlock_irqrestore(&hmc->lock, flags);
398 }
399 
400 /**
401  * ibmvmc_count_hmc_buffers - Count HMC Buffers
402  *
403  * @hmc_index:	HMC Index field
404  * @valid:	Valid number of buffers field
405  * @free:	Free number of buffers field
406  *
407  */
408 static void ibmvmc_count_hmc_buffers(u8 hmc_index, unsigned int *valid,
409 				     unsigned int *free)
410 {
411 	struct ibmvmc_buffer *buffer;
412 	unsigned long i;
413 	unsigned long flags;
414 
415 	if (hmc_index > ibmvmc.max_hmc_index)
416 		return;
417 
418 	if (!valid || !free)
419 		return;
420 
421 	*valid = 0; *free = 0;
422 
423 	buffer = hmcs[hmc_index].buffer;
424 	spin_lock_irqsave(&hmcs[hmc_index].lock, flags);
425 
426 	for (i = 0; i < ibmvmc_max_buf_pool_size; i++) {
427 		if (buffer[i].valid) {
428 			*valid = *valid + 1;
429 			if (buffer[i].free)
430 				*free = *free + 1;
431 		}
432 	}
433 
434 	spin_unlock_irqrestore(&hmcs[hmc_index].lock, flags);
435 }
436 
437 /**
438  * ibmvmc_get_free_hmc - Get Free HMC
439  *
440  * Return:
441  *	Pointer to an available HMC Connection
442  *	Null otherwise
443  */
444 static struct ibmvmc_hmc *ibmvmc_get_free_hmc(void)
445 {
446 	unsigned long i;
447 	unsigned long flags;
448 
449 	/*
450 	 * Find an available HMC connection.
451 	 */
452 	for (i = 0; i <= ibmvmc.max_hmc_index; i++) {
453 		spin_lock_irqsave(&hmcs[i].lock, flags);
454 		if (hmcs[i].state == ibmhmc_state_free) {
455 			hmcs[i].index = i;
456 			hmcs[i].state = ibmhmc_state_initial;
457 			spin_unlock_irqrestore(&hmcs[i].lock, flags);
458 			return &hmcs[i];
459 		}
460 		spin_unlock_irqrestore(&hmcs[i].lock, flags);
461 	}
462 
463 	return NULL;
464 }
465 
466 /**
467  * ibmvmc_return_hmc - Return an HMC Connection
468  *
469  * @hmc:		ibmvmc_hmc struct
470  * @release_readers:	Number of readers connected to session
471  *
472  * This function releases the HMC connections back into the pool.
473  *
474  * Return:
475  *	0 - Success
476  *	Non-zero - Failure
477  */
478 static int ibmvmc_return_hmc(struct ibmvmc_hmc *hmc, bool release_readers)
479 {
480 	struct ibmvmc_buffer *buffer;
481 	struct crq_server_adapter *adapter;
482 	struct vio_dev *vdev;
483 	unsigned long i;
484 	unsigned long flags;
485 
486 	if (!hmc || !hmc->adapter)
487 		return -EIO;
488 
489 	if (release_readers) {
490 		if (hmc->file_session) {
491 			struct ibmvmc_file_session *session = hmc->file_session;
492 
493 			session->valid = 0;
494 			wake_up_interruptible(&ibmvmc_read_wait);
495 		}
496 	}
497 
498 	adapter = hmc->adapter;
499 	vdev = to_vio_dev(adapter->dev);
500 
501 	spin_lock_irqsave(&hmc->lock, flags);
502 	hmc->index = 0;
503 	hmc->state = ibmhmc_state_free;
504 	hmc->queue_head = 0;
505 	hmc->queue_tail = 0;
506 	buffer = hmc->buffer;
507 	for (i = 0; i < ibmvmc_max_buf_pool_size; i++) {
508 		if (buffer[i].valid) {
509 			free_dma_buffer(vdev,
510 					ibmvmc.max_mtu,
511 					buffer[i].real_addr_local,
512 					buffer[i].dma_addr_local);
513 			dev_dbg(adapter->dev, "Forgot buffer id 0x%lx\n", i);
514 		}
515 		memset(&buffer[i], 0, sizeof(struct ibmvmc_buffer));
516 
517 		hmc->queue_outbound_msgs[i] = VMC_INVALID_BUFFER_ID;
518 	}
519 
520 	spin_unlock_irqrestore(&hmc->lock, flags);
521 
522 	return 0;
523 }
524 
525 /**
526  * ibmvmc_send_open - Interface Open
527  * @buffer: Pointer to ibmvmc_buffer struct
528  * @hmc: Pointer to ibmvmc_hmc struct
529  *
530  * This command is sent by the management partition as the result of a
531  * management partition device request. It causes the hypervisor to
532  * prepare a set of data buffers for the management application connection
533  * indicated HMC idx. A unique HMC Idx would be used if multiple management
534  * applications running concurrently were desired. Before responding to this
535  * command, the hypervisor must provide the management partition with at
536  * least one of these new buffers via the Add Buffer. This indicates whether
537  * the messages are inbound or outbound from the hypervisor.
538  *
539  * Return:
540  *	0 - Success
541  *	Non-zero - Failure
542  */
543 static int ibmvmc_send_open(struct ibmvmc_buffer *buffer,
544 			    struct ibmvmc_hmc *hmc)
545 {
546 	struct ibmvmc_crq_msg crq_msg;
547 	struct crq_server_adapter *adapter;
548 	__be64 *crq_as_u64 = (__be64 *)&crq_msg;
549 	int rc = 0;
550 
551 	if (!hmc || !hmc->adapter)
552 		return -EIO;
553 
554 	adapter = hmc->adapter;
555 
556 	dev_dbg(adapter->dev, "send_open: 0x%lx 0x%lx 0x%lx 0x%lx 0x%lx\n",
557 		(unsigned long)buffer->size, (unsigned long)adapter->liobn,
558 		(unsigned long)buffer->dma_addr_local,
559 		(unsigned long)adapter->riobn,
560 		(unsigned long)buffer->dma_addr_remote);
561 
562 	rc = h_copy_rdma(buffer->size,
563 			 adapter->liobn,
564 			 buffer->dma_addr_local,
565 			 adapter->riobn,
566 			 buffer->dma_addr_remote);
567 	if (rc) {
568 		dev_err(adapter->dev, "Error: In send_open, h_copy_rdma rc 0x%x\n",
569 			rc);
570 		return -EIO;
571 	}
572 
573 	hmc->state = ibmhmc_state_opening;
574 
575 	crq_msg.valid = 0x80;
576 	crq_msg.type = VMC_MSG_OPEN;
577 	crq_msg.status = 0;
578 	crq_msg.var1.rsvd = 0;
579 	crq_msg.hmc_session = hmc->session;
580 	crq_msg.hmc_index = hmc->index;
581 	crq_msg.var2.buffer_id = cpu_to_be16(buffer->id);
582 	crq_msg.rsvd = 0;
583 	crq_msg.var3.rsvd = 0;
584 
585 	ibmvmc_send_crq(adapter, be64_to_cpu(crq_as_u64[0]),
586 			be64_to_cpu(crq_as_u64[1]));
587 
588 	return rc;
589 }
590 
591 /**
592  * ibmvmc_send_close - Interface Close
593  * @hmc: Pointer to ibmvmc_hmc struct
594  *
595  * This command is sent by the management partition to terminate a
596  * management application to hypervisor connection. When this command is
597  * sent, the management partition has quiesced all I/O operations to all
598  * buffers associated with this management application connection, and
599  * has freed any storage for these buffers.
600  *
601  * Return:
602  *	0 - Success
603  *	Non-zero - Failure
604  */
605 static int ibmvmc_send_close(struct ibmvmc_hmc *hmc)
606 {
607 	struct ibmvmc_crq_msg crq_msg;
608 	struct crq_server_adapter *adapter;
609 	__be64 *crq_as_u64 = (__be64 *)&crq_msg;
610 	int rc = 0;
611 
612 	if (!hmc || !hmc->adapter)
613 		return -EIO;
614 
615 	adapter = hmc->adapter;
616 
617 	dev_info(adapter->dev, "CRQ send: close\n");
618 
619 	crq_msg.valid = 0x80;
620 	crq_msg.type = VMC_MSG_CLOSE;
621 	crq_msg.status = 0;
622 	crq_msg.var1.rsvd = 0;
623 	crq_msg.hmc_session = hmc->session;
624 	crq_msg.hmc_index = hmc->index;
625 	crq_msg.var2.rsvd = 0;
626 	crq_msg.rsvd = 0;
627 	crq_msg.var3.rsvd = 0;
628 
629 	ibmvmc_send_crq(adapter, be64_to_cpu(crq_as_u64[0]),
630 			be64_to_cpu(crq_as_u64[1]));
631 
632 	return rc;
633 }
634 
635 /**
636  * ibmvmc_send_capabilities - Send VMC Capabilities
637  *
638  * @adapter:	crq_server_adapter struct
639  *
640  * The capabilities message is an administrative message sent after the CRQ
641  * initialization sequence of messages and is used to exchange VMC capabilities
642  * between the management partition and the hypervisor. The management
643  * partition must send this message and the hypervisor must respond with VMC
644  * capabilities Response message before HMC interface message can begin. Any
645  * HMC interface messages received before the exchange of capabilities has
646  * complete are dropped.
647  *
648  * Return:
649  *	0 - Success
650  */
651 static int ibmvmc_send_capabilities(struct crq_server_adapter *adapter)
652 {
653 	struct ibmvmc_admin_crq_msg crq_msg;
654 	__be64 *crq_as_u64 = (__be64 *)&crq_msg;
655 
656 	dev_dbg(adapter->dev, "ibmvmc: CRQ send: capabilities\n");
657 	crq_msg.valid = 0x80;
658 	crq_msg.type = VMC_MSG_CAP;
659 	crq_msg.status = 0;
660 	crq_msg.rsvd[0] = 0;
661 	crq_msg.rsvd[1] = 0;
662 	crq_msg.max_hmc = ibmvmc_max_hmcs;
663 	crq_msg.max_mtu = cpu_to_be32(ibmvmc_max_mtu);
664 	crq_msg.pool_size = cpu_to_be16(ibmvmc_max_buf_pool_size);
665 	crq_msg.crq_size = cpu_to_be16(adapter->queue.size);
666 	crq_msg.version = cpu_to_be16(IBMVMC_PROTOCOL_VERSION);
667 
668 	ibmvmc_send_crq(adapter, be64_to_cpu(crq_as_u64[0]),
669 			be64_to_cpu(crq_as_u64[1]));
670 
671 	ibmvmc.state = ibmvmc_state_capabilities;
672 
673 	return 0;
674 }
675 
676 /**
677  * ibmvmc_send_add_buffer_resp - Add Buffer Response
678  *
679  * @adapter:	crq_server_adapter struct
680  * @status:	Status field
681  * @hmc_session: HMC Session field
682  * @hmc_index:	HMC Index field
683  * @buffer_id:	Buffer Id field
684  *
685  * This command is sent by the management partition to the hypervisor in
686  * response to the Add Buffer message. The Status field indicates the result of
687  * the command.
688  *
689  * Return:
690  *	0 - Success
691  */
692 static int ibmvmc_send_add_buffer_resp(struct crq_server_adapter *adapter,
693 				       u8 status, u8 hmc_session,
694 				       u8 hmc_index, u16 buffer_id)
695 {
696 	struct ibmvmc_crq_msg crq_msg;
697 	__be64 *crq_as_u64 = (__be64 *)&crq_msg;
698 
699 	dev_dbg(adapter->dev, "CRQ send: add_buffer_resp\n");
700 	crq_msg.valid = 0x80;
701 	crq_msg.type = VMC_MSG_ADD_BUF_RESP;
702 	crq_msg.status = status;
703 	crq_msg.var1.rsvd = 0;
704 	crq_msg.hmc_session = hmc_session;
705 	crq_msg.hmc_index = hmc_index;
706 	crq_msg.var2.buffer_id = cpu_to_be16(buffer_id);
707 	crq_msg.rsvd = 0;
708 	crq_msg.var3.rsvd = 0;
709 
710 	ibmvmc_send_crq(adapter, be64_to_cpu(crq_as_u64[0]),
711 			be64_to_cpu(crq_as_u64[1]));
712 
713 	return 0;
714 }
715 
716 /**
717  * ibmvmc_send_rem_buffer_resp - Remove Buffer Response
718  *
719  * @adapter:	crq_server_adapter struct
720  * @status:	Status field
721  * @hmc_session: HMC Session field
722  * @hmc_index:	HMC Index field
723  * @buffer_id:	Buffer Id field
724  *
725  * This command is sent by the management partition to the hypervisor in
726  * response to the Remove Buffer message. The Buffer ID field indicates
727  * which buffer the management partition selected to remove. The Status
728  * field indicates the result of the command.
729  *
730  * Return:
731  *	0 - Success
732  */
733 static int ibmvmc_send_rem_buffer_resp(struct crq_server_adapter *adapter,
734 				       u8 status, u8 hmc_session,
735 				       u8 hmc_index, u16 buffer_id)
736 {
737 	struct ibmvmc_crq_msg crq_msg;
738 	__be64 *crq_as_u64 = (__be64 *)&crq_msg;
739 
740 	dev_dbg(adapter->dev, "CRQ send: rem_buffer_resp\n");
741 	crq_msg.valid = 0x80;
742 	crq_msg.type = VMC_MSG_REM_BUF_RESP;
743 	crq_msg.status = status;
744 	crq_msg.var1.rsvd = 0;
745 	crq_msg.hmc_session = hmc_session;
746 	crq_msg.hmc_index = hmc_index;
747 	crq_msg.var2.buffer_id = cpu_to_be16(buffer_id);
748 	crq_msg.rsvd = 0;
749 	crq_msg.var3.rsvd = 0;
750 
751 	ibmvmc_send_crq(adapter, be64_to_cpu(crq_as_u64[0]),
752 			be64_to_cpu(crq_as_u64[1]));
753 
754 	return 0;
755 }
756 
757 /**
758  * ibmvmc_send_msg - Signal Message
759  *
760  * @adapter:	crq_server_adapter struct
761  * @buffer:	ibmvmc_buffer struct
762  * @hmc:	ibmvmc_hmc struct
763  * @msg_len:	message length field
764  *
765  * This command is sent between the management partition and the hypervisor
766  * in order to signal the arrival of an HMC protocol message. The command
767  * can be sent by both the management partition and the hypervisor. It is
768  * used for all traffic between the management application and the hypervisor,
769  * regardless of who initiated the communication.
770  *
771  * There is no response to this message.
772  *
773  * Return:
774  *	0 - Success
775  *	Non-zero - Failure
776  */
777 static int ibmvmc_send_msg(struct crq_server_adapter *adapter,
778 			   struct ibmvmc_buffer *buffer,
779 			   struct ibmvmc_hmc *hmc, int msg_len)
780 {
781 	struct ibmvmc_crq_msg crq_msg;
782 	__be64 *crq_as_u64 = (__be64 *)&crq_msg;
783 	int rc = 0;
784 
785 	dev_dbg(adapter->dev, "CRQ send: rdma to HV\n");
786 	rc = h_copy_rdma(msg_len,
787 			 adapter->liobn,
788 			 buffer->dma_addr_local,
789 			 adapter->riobn,
790 			 buffer->dma_addr_remote);
791 	if (rc) {
792 		dev_err(adapter->dev, "Error in send_msg, h_copy_rdma rc 0x%x\n",
793 			rc);
794 		return rc;
795 	}
796 
797 	crq_msg.valid = 0x80;
798 	crq_msg.type = VMC_MSG_SIGNAL;
799 	crq_msg.status = 0;
800 	crq_msg.var1.rsvd = 0;
801 	crq_msg.hmc_session = hmc->session;
802 	crq_msg.hmc_index = hmc->index;
803 	crq_msg.var2.buffer_id = cpu_to_be16(buffer->id);
804 	crq_msg.var3.msg_len = cpu_to_be32(msg_len);
805 	dev_dbg(adapter->dev, "CRQ send: msg to HV 0x%llx 0x%llx\n",
806 		be64_to_cpu(crq_as_u64[0]), be64_to_cpu(crq_as_u64[1]));
807 
808 	buffer->owner = VMC_BUF_OWNER_HV;
809 	ibmvmc_send_crq(adapter, be64_to_cpu(crq_as_u64[0]),
810 			be64_to_cpu(crq_as_u64[1]));
811 
812 	return rc;
813 }
814 
815 /**
816  * ibmvmc_open - Open Session
817  *
818  * @inode:	inode struct
819  * @file:	file struct
820  *
821  * Return:
822  *	0 - Success
823  *	Non-zero - Failure
824  */
825 static int ibmvmc_open(struct inode *inode, struct file *file)
826 {
827 	struct ibmvmc_file_session *session;
828 
829 	pr_debug("%s: inode = 0x%lx, file = 0x%lx, state = 0x%x\n", __func__,
830 		 (unsigned long)inode, (unsigned long)file,
831 		 ibmvmc.state);
832 
833 	session = kzalloc_obj(*session);
834 	if (!session)
835 		return -ENOMEM;
836 
837 	session->file = file;
838 	file->private_data = session;
839 
840 	return 0;
841 }
842 
843 /**
844  * ibmvmc_close - Close Session
845  *
846  * @inode:	inode struct
847  * @file:	file struct
848  *
849  * Return:
850  *	0 - Success
851  *	Non-zero - Failure
852  */
853 static int ibmvmc_close(struct inode *inode, struct file *file)
854 {
855 	struct ibmvmc_file_session *session;
856 	struct ibmvmc_hmc *hmc;
857 	int rc = 0;
858 	unsigned long flags;
859 
860 	pr_debug("%s: file = 0x%lx, state = 0x%x\n", __func__,
861 		 (unsigned long)file, ibmvmc.state);
862 
863 	session = file->private_data;
864 	if (!session)
865 		return -EIO;
866 
867 	hmc = session->hmc;
868 	if (hmc) {
869 		if (!hmc->adapter)
870 			return -EIO;
871 
872 		if (ibmvmc.state == ibmvmc_state_failed) {
873 			dev_warn(hmc->adapter->dev, "close: state_failed\n");
874 			return -EIO;
875 		}
876 
877 		spin_lock_irqsave(&hmc->lock, flags);
878 		if (hmc->state >= ibmhmc_state_opening) {
879 			rc = ibmvmc_send_close(hmc);
880 			if (rc)
881 				dev_warn(hmc->adapter->dev, "close: send_close failed.\n");
882 		}
883 		spin_unlock_irqrestore(&hmc->lock, flags);
884 	}
885 
886 	kfree_sensitive(session);
887 
888 	return rc;
889 }
890 
891 /**
892  * ibmvmc_read - Read
893  *
894  * @file:	file struct
895  * @buf:	Character buffer
896  * @nbytes:	Size in bytes
897  * @ppos:	Offset
898  *
899  * Return:
900  *	0 - Success
901  *	Non-zero - Failure
902  */
903 static ssize_t ibmvmc_read(struct file *file, char *buf, size_t nbytes,
904 			   loff_t *ppos)
905 {
906 	struct ibmvmc_file_session *session;
907 	struct ibmvmc_hmc *hmc;
908 	struct crq_server_adapter *adapter;
909 	struct ibmvmc_buffer *buffer;
910 	ssize_t n;
911 	ssize_t retval = 0;
912 	unsigned long flags;
913 	DEFINE_WAIT(wait);
914 
915 	pr_debug("ibmvmc: read: file = 0x%lx, buf = 0x%lx, nbytes = 0x%lx\n",
916 		 (unsigned long)file, (unsigned long)buf,
917 		 (unsigned long)nbytes);
918 
919 	if (nbytes == 0)
920 		return 0;
921 
922 	if (nbytes > ibmvmc.max_mtu) {
923 		pr_warn("ibmvmc: read: nbytes invalid 0x%x\n",
924 			(unsigned int)nbytes);
925 		return -EINVAL;
926 	}
927 
928 	session = file->private_data;
929 	if (!session) {
930 		pr_warn("ibmvmc: read: no session\n");
931 		return -EIO;
932 	}
933 
934 	hmc = session->hmc;
935 	if (!hmc) {
936 		pr_warn("ibmvmc: read: no hmc\n");
937 		return -EIO;
938 	}
939 
940 	adapter = hmc->adapter;
941 	if (!adapter) {
942 		pr_warn("ibmvmc: read: no adapter\n");
943 		return -EIO;
944 	}
945 
946 	do {
947 		prepare_to_wait(&ibmvmc_read_wait, &wait, TASK_INTERRUPTIBLE);
948 
949 		spin_lock_irqsave(&hmc->lock, flags);
950 		if (hmc->queue_tail != hmc->queue_head)
951 			/* Data is available */
952 			break;
953 
954 		spin_unlock_irqrestore(&hmc->lock, flags);
955 
956 		if (!session->valid) {
957 			retval = -EBADFD;
958 			goto out;
959 		}
960 		if (file->f_flags & O_NONBLOCK) {
961 			retval = -EAGAIN;
962 			goto out;
963 		}
964 
965 		schedule();
966 
967 		if (signal_pending(current)) {
968 			retval = -ERESTARTSYS;
969 			goto out;
970 		}
971 	} while (1);
972 
973 	buffer = &(hmc->buffer[hmc->queue_outbound_msgs[hmc->queue_tail]]);
974 	hmc->queue_tail++;
975 	if (hmc->queue_tail == ibmvmc_max_buf_pool_size)
976 		hmc->queue_tail = 0;
977 	spin_unlock_irqrestore(&hmc->lock, flags);
978 
979 	nbytes = min_t(size_t, nbytes, buffer->msg_len);
980 	n = copy_to_user((void *)buf, buffer->real_addr_local, nbytes);
981 	dev_dbg(adapter->dev, "read: copy to user nbytes = 0x%lx.\n", nbytes);
982 	ibmvmc_free_hmc_buffer(hmc, buffer);
983 	retval = nbytes;
984 
985 	if (n) {
986 		dev_warn(adapter->dev, "read: copy to user failed.\n");
987 		retval = -EFAULT;
988 	}
989 
990  out:
991 	finish_wait(&ibmvmc_read_wait, &wait);
992 	dev_dbg(adapter->dev, "read: out %ld\n", retval);
993 	return retval;
994 }
995 
996 /**
997  * ibmvmc_poll - Poll
998  *
999  * @file:	file struct
1000  * @wait:	Poll Table
1001  *
1002  * Return:
1003  *	poll.h return values
1004  */
1005 static unsigned int ibmvmc_poll(struct file *file, poll_table *wait)
1006 {
1007 	struct ibmvmc_file_session *session;
1008 	struct ibmvmc_hmc *hmc;
1009 	unsigned int mask = 0;
1010 
1011 	session = file->private_data;
1012 	if (!session)
1013 		return 0;
1014 
1015 	hmc = session->hmc;
1016 	if (!hmc)
1017 		return 0;
1018 
1019 	poll_wait(file, &ibmvmc_read_wait, wait);
1020 
1021 	if (hmc->queue_head != hmc->queue_tail)
1022 		mask |= POLLIN | POLLRDNORM;
1023 
1024 	return mask;
1025 }
1026 
1027 /**
1028  * ibmvmc_write - Write
1029  *
1030  * @file:	file struct
1031  * @buffer:	Character buffer
1032  * @count:	Count field
1033  * @ppos:	Offset
1034  *
1035  * Return:
1036  *	0 - Success
1037  *	Non-zero - Failure
1038  */
1039 static ssize_t ibmvmc_write(struct file *file, const char *buffer,
1040 			    size_t count, loff_t *ppos)
1041 {
1042 	struct inode *inode;
1043 	struct ibmvmc_buffer *vmc_buffer = NULL;
1044 	struct ibmvmc_file_session *session;
1045 	struct crq_server_adapter *adapter;
1046 	struct ibmvmc_hmc *hmc;
1047 	unsigned char *buf;
1048 	unsigned long flags;
1049 	size_t bytes;
1050 	const char *p = buffer;
1051 	size_t c = count;
1052 	int ret = 0;
1053 
1054 	session = file->private_data;
1055 	if (!session)
1056 		return -EIO;
1057 
1058 	hmc = session->hmc;
1059 	if (!hmc)
1060 		return -EIO;
1061 
1062 	spin_lock_irqsave(&hmc->lock, flags);
1063 	if (hmc->state == ibmhmc_state_free) {
1064 		/* HMC connection is not valid (possibly was reset under us). */
1065 		ret = -EIO;
1066 		goto out;
1067 	}
1068 
1069 	adapter = hmc->adapter;
1070 	if (!adapter) {
1071 		ret = -EIO;
1072 		goto out;
1073 	}
1074 
1075 	if (count > ibmvmc.max_mtu) {
1076 		dev_warn(adapter->dev, "invalid buffer size 0x%lx\n",
1077 			 (unsigned long)count);
1078 		ret = -EIO;
1079 		goto out;
1080 	}
1081 
1082 	/* Waiting for the open resp message to the ioctl(1) - retry */
1083 	if (hmc->state == ibmhmc_state_opening) {
1084 		ret = -EBUSY;
1085 		goto out;
1086 	}
1087 
1088 	/* Make sure the ioctl() was called & the open msg sent, and that
1089 	 * the HMC connection has not failed.
1090 	 */
1091 	if (hmc->state != ibmhmc_state_ready) {
1092 		ret = -EIO;
1093 		goto out;
1094 	}
1095 
1096 	vmc_buffer = ibmvmc_get_valid_hmc_buffer(hmc->index);
1097 	if (!vmc_buffer) {
1098 		/* No buffer available for the msg send, or we have not yet
1099 		 * completed the open/open_resp sequence.  Retry until this is
1100 		 * complete.
1101 		 */
1102 		ret = -EBUSY;
1103 		goto out;
1104 	}
1105 	if (!vmc_buffer->real_addr_local) {
1106 		dev_err(adapter->dev, "no buffer storage assigned\n");
1107 		ret = -EIO;
1108 		goto out;
1109 	}
1110 	buf = vmc_buffer->real_addr_local;
1111 
1112 	while (c > 0) {
1113 		bytes = min_t(size_t, c, vmc_buffer->size);
1114 
1115 		bytes -= copy_from_user(buf, p, bytes);
1116 		if (!bytes) {
1117 			ret = -EFAULT;
1118 			goto out;
1119 		}
1120 		c -= bytes;
1121 		p += bytes;
1122 	}
1123 	if (p == buffer)
1124 		goto out;
1125 
1126 	inode = file_inode(file);
1127 	inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
1128 	mark_inode_dirty(inode);
1129 
1130 	dev_dbg(adapter->dev, "write: file = 0x%lx, count = 0x%lx\n",
1131 		(unsigned long)file, (unsigned long)count);
1132 
1133 	if (ibmvmc_send_msg(adapter, vmc_buffer, hmc, count)) {
1134 		ret = -EIO;
1135 		goto out;
1136 	}
1137 	vmc_buffer = NULL;
1138 	ret = p - buffer;
1139  out:
1140 	if (vmc_buffer)
1141 		vmc_buffer->free = 1;
1142 	spin_unlock_irqrestore(&hmc->lock, flags);
1143 	return (ssize_t)(ret);
1144 }
1145 
1146 /**
1147  * ibmvmc_setup_hmc - Setup the HMC
1148  *
1149  * @session:	ibmvmc_file_session struct
1150  *
1151  * Return:
1152  *	0 - Success
1153  *	Non-zero - Failure
1154  */
1155 static long ibmvmc_setup_hmc(struct ibmvmc_file_session *session)
1156 {
1157 	struct ibmvmc_hmc *hmc;
1158 	unsigned int valid, free, index;
1159 
1160 	if (ibmvmc.state == ibmvmc_state_failed) {
1161 		pr_warn("ibmvmc: Reserve HMC: state_failed\n");
1162 		return -EIO;
1163 	}
1164 
1165 	if (ibmvmc.state < ibmvmc_state_ready) {
1166 		pr_warn("ibmvmc: Reserve HMC: not state_ready\n");
1167 		return -EAGAIN;
1168 	}
1169 
1170 	/* Device is busy until capabilities have been exchanged and we
1171 	 * have a generic buffer for each possible HMC connection.
1172 	 */
1173 	for (index = 0; index <= ibmvmc.max_hmc_index; index++) {
1174 		valid = 0;
1175 		ibmvmc_count_hmc_buffers(index, &valid, &free);
1176 		if (valid == 0) {
1177 			pr_warn("ibmvmc: buffers not ready for index %d\n",
1178 				index);
1179 			return -ENOBUFS;
1180 		}
1181 	}
1182 
1183 	/* Get an hmc object, and transition to ibmhmc_state_initial */
1184 	hmc = ibmvmc_get_free_hmc();
1185 	if (!hmc) {
1186 		pr_warn("%s: free hmc not found\n", __func__);
1187 		return -EBUSY;
1188 	}
1189 
1190 	hmc->session = hmc->session + 1;
1191 	if (hmc->session == 0xff)
1192 		hmc->session = 1;
1193 
1194 	session->hmc = hmc;
1195 	hmc->adapter = &ibmvmc_adapter;
1196 	hmc->file_session = session;
1197 	session->valid = 1;
1198 
1199 	return 0;
1200 }
1201 
1202 /**
1203  * ibmvmc_ioctl_sethmcid - IOCTL Set HMC ID
1204  *
1205  * @session:	ibmvmc_file_session struct
1206  * @new_hmc_id:	HMC id field
1207  *
1208  * IOCTL command to setup the hmc id
1209  *
1210  * Return:
1211  *	0 - Success
1212  *	Non-zero - Failure
1213  */
1214 static long ibmvmc_ioctl_sethmcid(struct ibmvmc_file_session *session,
1215 				  unsigned char __user *new_hmc_id)
1216 {
1217 	struct ibmvmc_hmc *hmc;
1218 	struct ibmvmc_buffer *buffer;
1219 	size_t bytes;
1220 	char print_buffer[HMC_ID_LEN + 1];
1221 	unsigned long flags;
1222 	long rc = 0;
1223 
1224 	/* Reserve HMC session */
1225 	hmc = session->hmc;
1226 	if (!hmc) {
1227 		rc = ibmvmc_setup_hmc(session);
1228 		if (rc)
1229 			return rc;
1230 
1231 		hmc = session->hmc;
1232 		if (!hmc) {
1233 			pr_err("ibmvmc: setup_hmc success but no hmc\n");
1234 			return -EIO;
1235 		}
1236 	}
1237 
1238 	if (hmc->state != ibmhmc_state_initial) {
1239 		pr_warn("ibmvmc: sethmcid: invalid state to send open 0x%x\n",
1240 			hmc->state);
1241 		return -EIO;
1242 	}
1243 
1244 	bytes = copy_from_user(hmc->hmc_id, new_hmc_id, HMC_ID_LEN);
1245 	if (bytes)
1246 		return -EFAULT;
1247 
1248 	/* Send Open Session command */
1249 	spin_lock_irqsave(&hmc->lock, flags);
1250 	buffer = ibmvmc_get_valid_hmc_buffer(hmc->index);
1251 	spin_unlock_irqrestore(&hmc->lock, flags);
1252 
1253 	if (!buffer || !buffer->real_addr_local) {
1254 		pr_warn("ibmvmc: sethmcid: no buffer available\n");
1255 		return -EIO;
1256 	}
1257 
1258 	strscpy(print_buffer, hmc->hmc_id, sizeof(print_buffer));
1259 	pr_info("ibmvmc: sethmcid: Set HMC ID: \"%s\"\n", print_buffer);
1260 
1261 	memcpy(buffer->real_addr_local, hmc->hmc_id, HMC_ID_LEN);
1262 	/* RDMA over ID, send open msg, change state to ibmhmc_state_opening */
1263 	rc = ibmvmc_send_open(buffer, hmc);
1264 
1265 	return rc;
1266 }
1267 
1268 /**
1269  * ibmvmc_ioctl_query - IOCTL Query
1270  *
1271  * @session:	ibmvmc_file_session struct
1272  * @ret_struct:	ibmvmc_query_struct
1273  *
1274  * Return:
1275  *	0 - Success
1276  *	Non-zero - Failure
1277  */
1278 static long ibmvmc_ioctl_query(struct ibmvmc_file_session *session,
1279 			       struct ibmvmc_query_struct __user *ret_struct)
1280 {
1281 	struct ibmvmc_query_struct query_struct;
1282 	size_t bytes;
1283 
1284 	memset(&query_struct, 0, sizeof(query_struct));
1285 	query_struct.have_vmc = (ibmvmc.state > ibmvmc_state_initial);
1286 	query_struct.state = ibmvmc.state;
1287 	query_struct.vmc_drc_index = ibmvmc.vmc_drc_index;
1288 
1289 	bytes = copy_to_user(ret_struct, &query_struct,
1290 			     sizeof(query_struct));
1291 	if (bytes)
1292 		return -EFAULT;
1293 
1294 	return 0;
1295 }
1296 
1297 /**
1298  * ibmvmc_ioctl_requestvmc - IOCTL Request VMC
1299  *
1300  * @session:	ibmvmc_file_session struct
1301  * @ret_vmc_index:	VMC Index
1302  *
1303  * Return:
1304  *	0 - Success
1305  *	Non-zero - Failure
1306  */
1307 static long ibmvmc_ioctl_requestvmc(struct ibmvmc_file_session *session,
1308 				    u32 __user *ret_vmc_index)
1309 {
1310 	/* TODO: (adreznec) Add locking to control multiple process access */
1311 	size_t bytes;
1312 	long rc;
1313 	u32 vmc_drc_index;
1314 
1315 	/* Call to request the VMC device from phyp*/
1316 	rc = h_request_vmc(&vmc_drc_index);
1317 	pr_debug("ibmvmc: requestvmc: H_REQUEST_VMC rc = 0x%lx\n", rc);
1318 
1319 	if (rc == H_SUCCESS) {
1320 		rc = 0;
1321 	} else if (rc == H_FUNCTION) {
1322 		pr_err("ibmvmc: requestvmc: h_request_vmc not supported\n");
1323 		return -EPERM;
1324 	} else if (rc == H_AUTHORITY) {
1325 		pr_err("ibmvmc: requestvmc: hypervisor denied vmc request\n");
1326 		return -EPERM;
1327 	} else if (rc == H_HARDWARE) {
1328 		pr_err("ibmvmc: requestvmc: hypervisor hardware fault\n");
1329 		return -EIO;
1330 	} else if (rc == H_RESOURCE) {
1331 		pr_err("ibmvmc: requestvmc: vmc resource unavailable\n");
1332 		return -ENODEV;
1333 	} else if (rc == H_NOT_AVAILABLE) {
1334 		pr_err("ibmvmc: requestvmc: system cannot be vmc managed\n");
1335 		return -EPERM;
1336 	} else if (rc == H_PARAMETER) {
1337 		pr_err("ibmvmc: requestvmc: invalid parameter\n");
1338 		return -EINVAL;
1339 	}
1340 
1341 	/* Success, set the vmc index in global struct */
1342 	ibmvmc.vmc_drc_index = vmc_drc_index;
1343 
1344 	bytes = copy_to_user(ret_vmc_index, &vmc_drc_index,
1345 			     sizeof(*ret_vmc_index));
1346 	if (bytes) {
1347 		pr_warn("ibmvmc: requestvmc: copy to user failed.\n");
1348 		return -EFAULT;
1349 	}
1350 	return rc;
1351 }
1352 
1353 /**
1354  * ibmvmc_ioctl - IOCTL
1355  *
1356  * @file:	file information
1357  * @cmd:	cmd field
1358  * @arg:	Argument field
1359  *
1360  * Return:
1361  *	0 - Success
1362  *	Non-zero - Failure
1363  */
1364 static long ibmvmc_ioctl(struct file *file,
1365 			 unsigned int cmd, unsigned long arg)
1366 {
1367 	struct ibmvmc_file_session *session = file->private_data;
1368 
1369 	pr_debug("ibmvmc: ioctl file=0x%lx, cmd=0x%x, arg=0x%lx, ses=0x%lx\n",
1370 		 (unsigned long)file, cmd, arg,
1371 		 (unsigned long)session);
1372 
1373 	if (!session) {
1374 		pr_warn("ibmvmc: ioctl: no session\n");
1375 		return -EIO;
1376 	}
1377 
1378 	switch (cmd) {
1379 	case VMC_IOCTL_SETHMCID:
1380 		return ibmvmc_ioctl_sethmcid(session,
1381 			(unsigned char __user *)arg);
1382 	case VMC_IOCTL_QUERY:
1383 		return ibmvmc_ioctl_query(session,
1384 			(struct ibmvmc_query_struct __user *)arg);
1385 	case VMC_IOCTL_REQUESTVMC:
1386 		return ibmvmc_ioctl_requestvmc(session,
1387 			(unsigned int __user *)arg);
1388 	default:
1389 		pr_warn("ibmvmc: unknown ioctl 0x%x\n", cmd);
1390 		return -EINVAL;
1391 	}
1392 }
1393 
1394 static const struct file_operations ibmvmc_fops = {
1395 	.owner		= THIS_MODULE,
1396 	.read		= ibmvmc_read,
1397 	.write		= ibmvmc_write,
1398 	.poll		= ibmvmc_poll,
1399 	.unlocked_ioctl	= ibmvmc_ioctl,
1400 	.open           = ibmvmc_open,
1401 	.release        = ibmvmc_close,
1402 };
1403 
1404 /**
1405  * ibmvmc_add_buffer - Add Buffer
1406  *
1407  * @adapter: crq_server_adapter struct
1408  * @crq:	ibmvmc_crq_msg struct
1409  *
1410  * This message transfers a buffer from hypervisor ownership to management
1411  * partition ownership. The LIOBA is obtained from the virtual TCE table
1412  * associated with the hypervisor side of the VMC device, and points to a
1413  * buffer of size MTU (as established in the capabilities exchange).
1414  *
1415  * Typical flow for ading buffers:
1416  * 1. A new management application connection is opened by the management
1417  *	partition.
1418  * 2. The hypervisor assigns new buffers for the traffic associated with
1419  *	that connection.
1420  * 3. The hypervisor sends VMC Add Buffer messages to the management
1421  *	partition, informing it of the new buffers.
1422  * 4. The hypervisor sends an HMC protocol message (to the management
1423  *	application) notifying it of the new buffers. This informs the
1424  *	application that it has buffers available for sending HMC
1425  *	commands.
1426  *
1427  * Return:
1428  *	0 - Success
1429  *	Non-zero - Failure
1430  */
1431 static int ibmvmc_add_buffer(struct crq_server_adapter *adapter,
1432 			     struct ibmvmc_crq_msg *crq)
1433 {
1434 	struct ibmvmc_buffer *buffer;
1435 	u8 hmc_index;
1436 	u8 hmc_session;
1437 	u16 buffer_id;
1438 	unsigned long flags;
1439 	int rc = 0;
1440 
1441 	if (!crq)
1442 		return -1;
1443 
1444 	hmc_session = crq->hmc_session;
1445 	hmc_index = crq->hmc_index;
1446 	buffer_id = be16_to_cpu(crq->var2.buffer_id);
1447 
1448 	if (hmc_index > ibmvmc.max_hmc_index) {
1449 		dev_err(adapter->dev, "add_buffer: invalid hmc_index = 0x%x\n",
1450 			hmc_index);
1451 		ibmvmc_send_add_buffer_resp(adapter, VMC_MSG_INVALID_HMC_INDEX,
1452 					    hmc_session, hmc_index, buffer_id);
1453 		return -1;
1454 	}
1455 
1456 	if (buffer_id >= ibmvmc.max_buffer_pool_size) {
1457 		dev_err(adapter->dev, "add_buffer: invalid buffer_id = 0x%x\n",
1458 			buffer_id);
1459 		ibmvmc_send_add_buffer_resp(adapter, VMC_MSG_INVALID_BUFFER_ID,
1460 					    hmc_session, hmc_index, buffer_id);
1461 		return -1;
1462 	}
1463 
1464 	spin_lock_irqsave(&hmcs[hmc_index].lock, flags);
1465 	buffer = &hmcs[hmc_index].buffer[buffer_id];
1466 
1467 	if (buffer->real_addr_local || buffer->dma_addr_local) {
1468 		dev_warn(adapter->dev, "add_buffer: already allocated id = 0x%lx\n",
1469 			 (unsigned long)buffer_id);
1470 		spin_unlock_irqrestore(&hmcs[hmc_index].lock, flags);
1471 		ibmvmc_send_add_buffer_resp(adapter, VMC_MSG_INVALID_BUFFER_ID,
1472 					    hmc_session, hmc_index, buffer_id);
1473 		return -1;
1474 	}
1475 
1476 	buffer->real_addr_local = alloc_dma_buffer(to_vio_dev(adapter->dev),
1477 						   ibmvmc.max_mtu,
1478 						   &buffer->dma_addr_local);
1479 
1480 	if (!buffer->real_addr_local) {
1481 		dev_err(adapter->dev, "add_buffer: alloc_dma_buffer failed.\n");
1482 		spin_unlock_irqrestore(&hmcs[hmc_index].lock, flags);
1483 		ibmvmc_send_add_buffer_resp(adapter, VMC_MSG_INTERFACE_FAILURE,
1484 					    hmc_session, hmc_index, buffer_id);
1485 		return -1;
1486 	}
1487 
1488 	buffer->dma_addr_remote = be32_to_cpu(crq->var3.lioba);
1489 	buffer->size = ibmvmc.max_mtu;
1490 	buffer->owner = crq->var1.owner;
1491 	buffer->free = 1;
1492 	/* Must ensure valid==1 is observable only after all other fields are */
1493 	dma_wmb();
1494 	buffer->valid = 1;
1495 	buffer->id = buffer_id;
1496 
1497 	dev_dbg(adapter->dev, "add_buffer: successfully added a buffer:\n");
1498 	dev_dbg(adapter->dev, "   index: %d, session: %d, buffer: 0x%x, owner: %d\n",
1499 		hmc_index, hmc_session, buffer_id, buffer->owner);
1500 	dev_dbg(adapter->dev, "   local: 0x%x, remote: 0x%x\n",
1501 		(u32)buffer->dma_addr_local,
1502 		(u32)buffer->dma_addr_remote);
1503 	spin_unlock_irqrestore(&hmcs[hmc_index].lock, flags);
1504 
1505 	ibmvmc_send_add_buffer_resp(adapter, VMC_MSG_SUCCESS, hmc_session,
1506 				    hmc_index, buffer_id);
1507 
1508 	return rc;
1509 }
1510 
1511 /**
1512  * ibmvmc_rem_buffer - Remove Buffer
1513  *
1514  * @adapter: crq_server_adapter struct
1515  * @crq:	ibmvmc_crq_msg struct
1516  *
1517  * This message requests an HMC buffer to be transferred from management
1518  * partition ownership to hypervisor ownership. The management partition may
1519  * not be able to satisfy the request at a particular point in time if all its
1520  * buffers are in use. The management partition requires a depth of at least
1521  * one inbound buffer to allow management application commands to flow to the
1522  * hypervisor. It is, therefore, an interface error for the hypervisor to
1523  * attempt to remove the management partition's last buffer.
1524  *
1525  * The hypervisor is expected to manage buffer usage with the management
1526  * application directly and inform the management partition when buffers may be
1527  * removed. The typical flow for removing buffers:
1528  *
1529  * 1. The management application no longer needs a communication path to a
1530  *	particular hypervisor function. That function is closed.
1531  * 2. The hypervisor and the management application quiesce all traffic to that
1532  *	function. The hypervisor requests a reduction in buffer pool size.
1533  * 3. The management application acknowledges the reduction in buffer pool size.
1534  * 4. The hypervisor sends a Remove Buffer message to the management partition,
1535  *	informing it of the reduction in buffers.
1536  * 5. The management partition verifies it can remove the buffer. This is
1537  *	possible if buffers have been quiesced.
1538  *
1539  * Return:
1540  *	0 - Success
1541  *	Non-zero - Failure
1542  */
1543 /*
1544  * The hypervisor requested that we pick an unused buffer, and return it.
1545  * Before sending the buffer back, we free any storage associated with the
1546  * buffer.
1547  */
1548 static int ibmvmc_rem_buffer(struct crq_server_adapter *adapter,
1549 			     struct ibmvmc_crq_msg *crq)
1550 {
1551 	struct ibmvmc_buffer *buffer;
1552 	u8 hmc_index;
1553 	u8 hmc_session;
1554 	u16 buffer_id = 0;
1555 	unsigned long flags;
1556 	int rc = 0;
1557 
1558 	if (!crq)
1559 		return -1;
1560 
1561 	hmc_session = crq->hmc_session;
1562 	hmc_index = crq->hmc_index;
1563 
1564 	if (hmc_index > ibmvmc.max_hmc_index) {
1565 		dev_warn(adapter->dev, "rem_buffer: invalid hmc_index = 0x%x\n",
1566 			 hmc_index);
1567 		ibmvmc_send_rem_buffer_resp(adapter, VMC_MSG_INVALID_HMC_INDEX,
1568 					    hmc_session, hmc_index, buffer_id);
1569 		return -1;
1570 	}
1571 
1572 	spin_lock_irqsave(&hmcs[hmc_index].lock, flags);
1573 	buffer = ibmvmc_get_free_hmc_buffer(adapter, hmc_index);
1574 	if (!buffer) {
1575 		dev_info(adapter->dev, "rem_buffer: no buffer to remove\n");
1576 		spin_unlock_irqrestore(&hmcs[hmc_index].lock, flags);
1577 		ibmvmc_send_rem_buffer_resp(adapter, VMC_MSG_NO_BUFFER,
1578 					    hmc_session, hmc_index,
1579 					    VMC_INVALID_BUFFER_ID);
1580 		return -1;
1581 	}
1582 
1583 	buffer_id = buffer->id;
1584 
1585 	if (buffer->valid)
1586 		free_dma_buffer(to_vio_dev(adapter->dev),
1587 				ibmvmc.max_mtu,
1588 				buffer->real_addr_local,
1589 				buffer->dma_addr_local);
1590 
1591 	memset(buffer, 0, sizeof(struct ibmvmc_buffer));
1592 	spin_unlock_irqrestore(&hmcs[hmc_index].lock, flags);
1593 
1594 	dev_dbg(adapter->dev, "rem_buffer: removed buffer 0x%x.\n", buffer_id);
1595 	ibmvmc_send_rem_buffer_resp(adapter, VMC_MSG_SUCCESS, hmc_session,
1596 				    hmc_index, buffer_id);
1597 
1598 	return rc;
1599 }
1600 
1601 static int ibmvmc_recv_msg(struct crq_server_adapter *adapter,
1602 			   struct ibmvmc_crq_msg *crq)
1603 {
1604 	struct ibmvmc_buffer *buffer;
1605 	struct ibmvmc_hmc *hmc;
1606 	unsigned long msg_len;
1607 	u8 hmc_index;
1608 	u8 hmc_session;
1609 	u16 buffer_id;
1610 	unsigned long flags;
1611 	int rc = 0;
1612 
1613 	if (!crq)
1614 		return -1;
1615 
1616 	/* Hypervisor writes CRQs directly into our memory in big endian */
1617 	dev_dbg(adapter->dev, "Recv_msg: msg from HV 0x%016llx 0x%016llx\n",
1618 		be64_to_cpu(*((unsigned long *)crq)),
1619 		be64_to_cpu(*(((unsigned long *)crq) + 1)));
1620 
1621 	hmc_session = crq->hmc_session;
1622 	hmc_index = crq->hmc_index;
1623 	buffer_id = be16_to_cpu(crq->var2.buffer_id);
1624 	msg_len = be32_to_cpu(crq->var3.msg_len);
1625 
1626 	if (hmc_index > ibmvmc.max_hmc_index) {
1627 		dev_err(adapter->dev, "Recv_msg: invalid hmc_index = 0x%x\n",
1628 			hmc_index);
1629 		ibmvmc_send_add_buffer_resp(adapter, VMC_MSG_INVALID_HMC_INDEX,
1630 					    hmc_session, hmc_index, buffer_id);
1631 		return -1;
1632 	}
1633 
1634 	if (buffer_id >= ibmvmc.max_buffer_pool_size) {
1635 		dev_err(adapter->dev, "Recv_msg: invalid buffer_id = 0x%x\n",
1636 			buffer_id);
1637 		ibmvmc_send_add_buffer_resp(adapter, VMC_MSG_INVALID_BUFFER_ID,
1638 					    hmc_session, hmc_index, buffer_id);
1639 		return -1;
1640 	}
1641 
1642 	hmc = &hmcs[hmc_index];
1643 	spin_lock_irqsave(&hmc->lock, flags);
1644 
1645 	if (hmc->state == ibmhmc_state_free) {
1646 		dev_err(adapter->dev, "Recv_msg: invalid hmc state = 0x%x\n",
1647 			hmc->state);
1648 		/* HMC connection is not valid (possibly was reset under us). */
1649 		spin_unlock_irqrestore(&hmc->lock, flags);
1650 		return -1;
1651 	}
1652 
1653 	buffer = &hmc->buffer[buffer_id];
1654 
1655 	if (buffer->valid == 0 || buffer->owner == VMC_BUF_OWNER_ALPHA) {
1656 		dev_err(adapter->dev, "Recv_msg: not valid, or not HV.  0x%x 0x%x\n",
1657 			buffer->valid, buffer->owner);
1658 		spin_unlock_irqrestore(&hmc->lock, flags);
1659 		return -1;
1660 	}
1661 
1662 	if (msg_len > buffer->size) {
1663 		dev_err(adapter->dev, "Recv_msg: msg_len 0x%lx exceeds buffer size 0x%x\n",
1664 			msg_len, buffer->size);
1665 		spin_unlock_irqrestore(&hmc->lock, flags);
1666 		return -1;
1667 	}
1668 
1669 	/* RDMA the data into the partition. */
1670 	rc = h_copy_rdma(msg_len,
1671 			 adapter->riobn,
1672 			 buffer->dma_addr_remote,
1673 			 adapter->liobn,
1674 			 buffer->dma_addr_local);
1675 
1676 	dev_dbg(adapter->dev, "Recv_msg: msg_len = 0x%x, buffer_id = 0x%x, queue_head = 0x%x, hmc_idx = 0x%x\n",
1677 		(unsigned int)msg_len, (unsigned int)buffer_id,
1678 		(unsigned int)hmc->queue_head, (unsigned int)hmc_index);
1679 	buffer->msg_len = msg_len;
1680 	buffer->free = 0;
1681 	buffer->owner = VMC_BUF_OWNER_ALPHA;
1682 
1683 	if (rc) {
1684 		dev_err(adapter->dev, "Failure in recv_msg: h_copy_rdma = 0x%x\n",
1685 			rc);
1686 		spin_unlock_irqrestore(&hmc->lock, flags);
1687 		return -1;
1688 	}
1689 
1690 	/* Must be locked because read operates on the same data */
1691 	hmc->queue_outbound_msgs[hmc->queue_head] = buffer_id;
1692 	hmc->queue_head++;
1693 	if (hmc->queue_head == ibmvmc_max_buf_pool_size)
1694 		hmc->queue_head = 0;
1695 
1696 	if (hmc->queue_head == hmc->queue_tail)
1697 		dev_err(adapter->dev, "outbound buffer queue wrapped.\n");
1698 
1699 	spin_unlock_irqrestore(&hmc->lock, flags);
1700 
1701 	wake_up_interruptible(&ibmvmc_read_wait);
1702 
1703 	return 0;
1704 }
1705 
1706 /**
1707  * ibmvmc_process_capabilities - Process Capabilities
1708  *
1709  * @adapter:	crq_server_adapter struct
1710  * @crqp:	ibmvmc_crq_msg struct
1711  *
1712  */
1713 static void ibmvmc_process_capabilities(struct crq_server_adapter *adapter,
1714 					struct ibmvmc_crq_msg *crqp)
1715 {
1716 	struct ibmvmc_admin_crq_msg *crq = (struct ibmvmc_admin_crq_msg *)crqp;
1717 
1718 	if ((be16_to_cpu(crq->version) >> 8) !=
1719 			(IBMVMC_PROTOCOL_VERSION >> 8)) {
1720 		dev_err(adapter->dev, "init failed, incompatible versions 0x%x 0x%x\n",
1721 			be16_to_cpu(crq->version),
1722 			IBMVMC_PROTOCOL_VERSION);
1723 		ibmvmc.state = ibmvmc_state_failed;
1724 		return;
1725 	}
1726 
1727 	ibmvmc.max_mtu = min_t(u32, ibmvmc_max_mtu, be32_to_cpu(crq->max_mtu));
1728 	ibmvmc.max_buffer_pool_size = min_t(u16, ibmvmc_max_buf_pool_size,
1729 					    be16_to_cpu(crq->pool_size));
1730 	ibmvmc.max_hmc_index = min_t(u8, ibmvmc_max_hmcs, crq->max_hmc) - 1;
1731 	ibmvmc.state = ibmvmc_state_ready;
1732 
1733 	dev_info(adapter->dev, "Capabilities: mtu=0x%x, pool_size=0x%x, max_hmc=0x%x\n",
1734 		 ibmvmc.max_mtu, ibmvmc.max_buffer_pool_size,
1735 		 ibmvmc.max_hmc_index);
1736 }
1737 
1738 /**
1739  * ibmvmc_validate_hmc_session - Validate HMC Session
1740  *
1741  * @adapter:	crq_server_adapter struct
1742  * @crq:	ibmvmc_crq_msg struct
1743  *
1744  * Return:
1745  *	0 - Success
1746  *	Non-zero - Failure
1747  */
1748 static int ibmvmc_validate_hmc_session(struct crq_server_adapter *adapter,
1749 				       struct ibmvmc_crq_msg *crq)
1750 {
1751 	unsigned char hmc_index;
1752 
1753 	hmc_index = crq->hmc_index;
1754 
1755 	if (crq->hmc_session == 0)
1756 		return 0;
1757 
1758 	if (hmc_index > ibmvmc.max_hmc_index)
1759 		return -1;
1760 
1761 	if (hmcs[hmc_index].session != crq->hmc_session) {
1762 		dev_warn(adapter->dev, "Drop, bad session: expected 0x%x, recv 0x%x\n",
1763 			 hmcs[hmc_index].session, crq->hmc_session);
1764 		return -1;
1765 	}
1766 
1767 	return 0;
1768 }
1769 
1770 /**
1771  * ibmvmc_reset - Reset
1772  *
1773  * @adapter:	crq_server_adapter struct
1774  * @xport_event:	export_event field
1775  *
1776  * Closes all HMC sessions and conditionally schedules a CRQ reset.
1777  * @xport_event: If true, the partner closed their CRQ; we don't need to reset.
1778  *               If false, we need to schedule a CRQ reset.
1779  */
1780 static void ibmvmc_reset(struct crq_server_adapter *adapter, bool xport_event)
1781 {
1782 	int i;
1783 
1784 	if (ibmvmc.state != ibmvmc_state_sched_reset) {
1785 		dev_info(adapter->dev, "*** Reset to initial state.\n");
1786 		for (i = 0; i < ibmvmc_max_hmcs; i++)
1787 			ibmvmc_return_hmc(&hmcs[i], xport_event);
1788 
1789 		if (xport_event) {
1790 			/* CRQ was closed by the partner.  We don't need to do
1791 			 * anything except set ourself to the correct state to
1792 			 * handle init msgs.
1793 			 */
1794 			ibmvmc.state = ibmvmc_state_crqinit;
1795 		} else {
1796 			/* The partner did not close their CRQ - instead, we're
1797 			 * closing the CRQ on our end. Need to schedule this
1798 			 * for process context, because CRQ reset may require a
1799 			 * sleep.
1800 			 *
1801 			 * Setting ibmvmc.state here immediately prevents
1802 			 * ibmvmc_open from completing until the reset
1803 			 * completes in process context.
1804 			 */
1805 			ibmvmc.state = ibmvmc_state_sched_reset;
1806 			dev_dbg(adapter->dev, "Device reset scheduled");
1807 			wake_up_interruptible(&adapter->reset_wait_queue);
1808 		}
1809 	}
1810 }
1811 
1812 /**
1813  * ibmvmc_reset_task - Reset Task
1814  *
1815  * @data:	Data field
1816  *
1817  * Performs a CRQ reset of the VMC device in process context.
1818  * NOTE: This function should not be called directly, use ibmvmc_reset.
1819  */
1820 static int ibmvmc_reset_task(void *data)
1821 {
1822 	struct crq_server_adapter *adapter = data;
1823 	int rc;
1824 
1825 	set_user_nice(current, -20);
1826 
1827 	while (!kthread_should_stop()) {
1828 		wait_event_interruptible(adapter->reset_wait_queue,
1829 			(ibmvmc.state == ibmvmc_state_sched_reset) ||
1830 			kthread_should_stop());
1831 
1832 		if (kthread_should_stop())
1833 			break;
1834 
1835 		dev_dbg(adapter->dev, "CRQ resetting in process context");
1836 		tasklet_disable(&adapter->work_task);
1837 
1838 		rc = ibmvmc_reset_crq_queue(adapter);
1839 
1840 		if (rc != H_SUCCESS && rc != H_RESOURCE) {
1841 			dev_err(adapter->dev, "Error initializing CRQ.  rc = 0x%x\n",
1842 				rc);
1843 			ibmvmc.state = ibmvmc_state_failed;
1844 		} else {
1845 			ibmvmc.state = ibmvmc_state_crqinit;
1846 
1847 			if (ibmvmc_send_crq(adapter, 0xC001000000000000LL, 0)
1848 			    != 0 && rc != H_RESOURCE)
1849 				dev_warn(adapter->dev, "Failed to send initialize CRQ message\n");
1850 		}
1851 
1852 		vio_enable_interrupts(to_vio_dev(adapter->dev));
1853 		tasklet_enable(&adapter->work_task);
1854 	}
1855 
1856 	return 0;
1857 }
1858 
1859 /**
1860  * ibmvmc_process_open_resp - Process Open Response
1861  *
1862  * @crq: ibmvmc_crq_msg struct
1863  * @adapter:    crq_server_adapter struct
1864  *
1865  * This command is sent by the hypervisor in response to the Interface
1866  * Open message. When this message is received, the indicated buffer is
1867  * again available for management partition use.
1868  */
1869 static void ibmvmc_process_open_resp(struct ibmvmc_crq_msg *crq,
1870 				     struct crq_server_adapter *adapter)
1871 {
1872 	unsigned char hmc_index;
1873 	unsigned short buffer_id;
1874 
1875 	hmc_index = crq->hmc_index;
1876 	if (hmc_index > ibmvmc.max_hmc_index) {
1877 		/* Why would PHYP give an index > max negotiated? */
1878 		ibmvmc_reset(adapter, false);
1879 		return;
1880 	}
1881 
1882 	if (crq->status) {
1883 		dev_warn(adapter->dev, "open_resp: failed - status 0x%x\n",
1884 			 crq->status);
1885 		ibmvmc_return_hmc(&hmcs[hmc_index], false);
1886 		return;
1887 	}
1888 
1889 	if (hmcs[hmc_index].state == ibmhmc_state_opening) {
1890 		buffer_id = be16_to_cpu(crq->var2.buffer_id);
1891 		if (buffer_id >= ibmvmc.max_buffer_pool_size) {
1892 			dev_err(adapter->dev, "open_resp: invalid buffer_id = 0x%x\n",
1893 				buffer_id);
1894 			hmcs[hmc_index].state = ibmhmc_state_failed;
1895 		} else {
1896 			ibmvmc_free_hmc_buffer(&hmcs[hmc_index],
1897 					       &hmcs[hmc_index].buffer[buffer_id]);
1898 			hmcs[hmc_index].state = ibmhmc_state_ready;
1899 			dev_dbg(adapter->dev, "open_resp: set hmc state = ready\n");
1900 		}
1901 	} else {
1902 		dev_warn(adapter->dev, "open_resp: invalid hmc state (0x%x)\n",
1903 			 hmcs[hmc_index].state);
1904 	}
1905 }
1906 
1907 /**
1908  * ibmvmc_process_close_resp - Process Close Response
1909  *
1910  * @crq: ibmvmc_crq_msg struct
1911  * @adapter:    crq_server_adapter struct
1912  *
1913  * This command is sent by the hypervisor in response to the managemant
1914  * application Interface Close message.
1915  *
1916  * If the close fails, simply reset the entire driver as the state of the VMC
1917  * must be in tough shape.
1918  */
1919 static void ibmvmc_process_close_resp(struct ibmvmc_crq_msg *crq,
1920 				      struct crq_server_adapter *adapter)
1921 {
1922 	unsigned char hmc_index;
1923 
1924 	hmc_index = crq->hmc_index;
1925 	if (hmc_index > ibmvmc.max_hmc_index) {
1926 		ibmvmc_reset(adapter, false);
1927 		return;
1928 	}
1929 
1930 	if (crq->status) {
1931 		dev_warn(adapter->dev, "close_resp: failed - status 0x%x\n",
1932 			 crq->status);
1933 		ibmvmc_reset(adapter, false);
1934 		return;
1935 	}
1936 
1937 	ibmvmc_return_hmc(&hmcs[hmc_index], false);
1938 }
1939 
1940 /**
1941  * ibmvmc_crq_process - Process CRQ
1942  *
1943  * @adapter:    crq_server_adapter struct
1944  * @crq:	ibmvmc_crq_msg struct
1945  *
1946  * Process the CRQ message based upon the type of message received.
1947  *
1948  */
1949 static void ibmvmc_crq_process(struct crq_server_adapter *adapter,
1950 			       struct ibmvmc_crq_msg *crq)
1951 {
1952 	switch (crq->type) {
1953 	case VMC_MSG_CAP_RESP:
1954 		dev_dbg(adapter->dev, "CRQ recv: capabilities resp (0x%x)\n",
1955 			crq->type);
1956 		if (ibmvmc.state == ibmvmc_state_capabilities)
1957 			ibmvmc_process_capabilities(adapter, crq);
1958 		else
1959 			dev_warn(adapter->dev, "caps msg invalid in state 0x%x\n",
1960 				 ibmvmc.state);
1961 		break;
1962 	case VMC_MSG_OPEN_RESP:
1963 		dev_dbg(adapter->dev, "CRQ recv: open resp (0x%x)\n",
1964 			crq->type);
1965 		if (ibmvmc_validate_hmc_session(adapter, crq) == 0)
1966 			ibmvmc_process_open_resp(crq, adapter);
1967 		break;
1968 	case VMC_MSG_ADD_BUF:
1969 		dev_dbg(adapter->dev, "CRQ recv: add buf (0x%x)\n",
1970 			crq->type);
1971 		if (ibmvmc_validate_hmc_session(adapter, crq) == 0)
1972 			ibmvmc_add_buffer(adapter, crq);
1973 		break;
1974 	case VMC_MSG_REM_BUF:
1975 		dev_dbg(adapter->dev, "CRQ recv: rem buf (0x%x)\n",
1976 			crq->type);
1977 		if (ibmvmc_validate_hmc_session(adapter, crq) == 0)
1978 			ibmvmc_rem_buffer(adapter, crq);
1979 		break;
1980 	case VMC_MSG_SIGNAL:
1981 		dev_dbg(adapter->dev, "CRQ recv: signal msg (0x%x)\n",
1982 			crq->type);
1983 		if (ibmvmc_validate_hmc_session(adapter, crq) == 0)
1984 			ibmvmc_recv_msg(adapter, crq);
1985 		break;
1986 	case VMC_MSG_CLOSE_RESP:
1987 		dev_dbg(adapter->dev, "CRQ recv: close resp (0x%x)\n",
1988 			crq->type);
1989 		if (ibmvmc_validate_hmc_session(adapter, crq) == 0)
1990 			ibmvmc_process_close_resp(crq, adapter);
1991 		break;
1992 	case VMC_MSG_CAP:
1993 	case VMC_MSG_OPEN:
1994 	case VMC_MSG_CLOSE:
1995 	case VMC_MSG_ADD_BUF_RESP:
1996 	case VMC_MSG_REM_BUF_RESP:
1997 		dev_warn(adapter->dev, "CRQ recv: unexpected msg (0x%x)\n",
1998 			 crq->type);
1999 		break;
2000 	default:
2001 		dev_warn(adapter->dev, "CRQ recv: unknown msg (0x%x)\n",
2002 			 crq->type);
2003 		break;
2004 	}
2005 }
2006 
2007 /**
2008  * ibmvmc_handle_crq_init - Handle CRQ Init
2009  *
2010  * @crq:	ibmvmc_crq_msg struct
2011  * @adapter:	crq_server_adapter struct
2012  *
2013  * Handle the type of crq initialization based on whether
2014  * it is a message or a response.
2015  *
2016  */
2017 static void ibmvmc_handle_crq_init(struct ibmvmc_crq_msg *crq,
2018 				   struct crq_server_adapter *adapter)
2019 {
2020 	switch (crq->type) {
2021 	case 0x01:	/* Initialization message */
2022 		dev_dbg(adapter->dev, "CRQ recv: CRQ init msg - state 0x%x\n",
2023 			ibmvmc.state);
2024 		if (ibmvmc.state == ibmvmc_state_crqinit) {
2025 			/* Send back a response */
2026 			if (ibmvmc_send_crq(adapter, 0xC002000000000000,
2027 					    0) == 0)
2028 				ibmvmc_send_capabilities(adapter);
2029 			else
2030 				dev_err(adapter->dev, " Unable to send init rsp\n");
2031 		} else {
2032 			dev_err(adapter->dev, "Invalid state 0x%x mtu = 0x%x\n",
2033 				ibmvmc.state, ibmvmc.max_mtu);
2034 		}
2035 
2036 		break;
2037 	case 0x02:	/* Initialization response */
2038 		dev_dbg(adapter->dev, "CRQ recv: initialization resp msg - state 0x%x\n",
2039 			ibmvmc.state);
2040 		if (ibmvmc.state == ibmvmc_state_crqinit)
2041 			ibmvmc_send_capabilities(adapter);
2042 		break;
2043 	default:
2044 		dev_warn(adapter->dev, "Unknown crq message type 0x%lx\n",
2045 			 (unsigned long)crq->type);
2046 	}
2047 }
2048 
2049 /**
2050  * ibmvmc_handle_crq - Handle CRQ
2051  *
2052  * @crq:	ibmvmc_crq_msg struct
2053  * @adapter:	crq_server_adapter struct
2054  *
2055  * Read the command elements from the command queue and execute the
2056  * requests based upon the type of crq message.
2057  *
2058  */
2059 static void ibmvmc_handle_crq(struct ibmvmc_crq_msg *crq,
2060 			      struct crq_server_adapter *adapter)
2061 {
2062 	switch (crq->valid) {
2063 	case 0xC0:		/* initialization */
2064 		ibmvmc_handle_crq_init(crq, adapter);
2065 		break;
2066 	case 0xFF:	/* Hypervisor telling us the connection is closed */
2067 		dev_warn(adapter->dev, "CRQ recv: virtual adapter failed - resetting.\n");
2068 		ibmvmc_reset(adapter, true);
2069 		break;
2070 	case 0x80:	/* real payload */
2071 		ibmvmc_crq_process(adapter, crq);
2072 		break;
2073 	default:
2074 		dev_warn(adapter->dev, "CRQ recv: unknown msg 0x%02x.\n",
2075 			 crq->valid);
2076 		break;
2077 	}
2078 }
2079 
2080 static void ibmvmc_task(unsigned long data)
2081 {
2082 	struct crq_server_adapter *adapter =
2083 		(struct crq_server_adapter *)data;
2084 	struct vio_dev *vdev = to_vio_dev(adapter->dev);
2085 	struct ibmvmc_crq_msg *crq;
2086 	int done = 0;
2087 
2088 	while (!done) {
2089 		/* Pull all the valid messages off the CRQ */
2090 		while ((crq = crq_queue_next_crq(&adapter->queue)) != NULL) {
2091 			ibmvmc_handle_crq(crq, adapter);
2092 			crq->valid = 0x00;
2093 			/* CRQ reset was requested, stop processing CRQs.
2094 			 * Interrupts will be re-enabled by the reset task.
2095 			 */
2096 			if (ibmvmc.state == ibmvmc_state_sched_reset)
2097 				return;
2098 		}
2099 
2100 		vio_enable_interrupts(vdev);
2101 		crq = crq_queue_next_crq(&adapter->queue);
2102 		if (crq) {
2103 			vio_disable_interrupts(vdev);
2104 			ibmvmc_handle_crq(crq, adapter);
2105 			crq->valid = 0x00;
2106 			/* CRQ reset was requested, stop processing CRQs.
2107 			 * Interrupts will be re-enabled by the reset task.
2108 			 */
2109 			if (ibmvmc.state == ibmvmc_state_sched_reset)
2110 				return;
2111 		} else {
2112 			done = 1;
2113 		}
2114 	}
2115 }
2116 
2117 /**
2118  * ibmvmc_init_crq_queue - Init CRQ Queue
2119  *
2120  * @adapter:	crq_server_adapter struct
2121  *
2122  * Return:
2123  *	0 - Success
2124  *	Non-zero - Failure
2125  */
2126 static int ibmvmc_init_crq_queue(struct crq_server_adapter *adapter)
2127 {
2128 	struct vio_dev *vdev = to_vio_dev(adapter->dev);
2129 	struct crq_queue *queue = &adapter->queue;
2130 	int rc = 0;
2131 	int retrc = 0;
2132 
2133 	queue->msgs = (struct ibmvmc_crq_msg *)get_zeroed_page(GFP_KERNEL);
2134 
2135 	if (!queue->msgs)
2136 		goto malloc_failed;
2137 
2138 	queue->size = PAGE_SIZE / sizeof(*queue->msgs);
2139 
2140 	queue->msg_token = dma_map_single(adapter->dev, queue->msgs,
2141 					  queue->size * sizeof(*queue->msgs),
2142 					  DMA_BIDIRECTIONAL);
2143 
2144 	if (dma_mapping_error(adapter->dev, queue->msg_token))
2145 		goto map_failed;
2146 
2147 	retrc = plpar_hcall_norets(H_REG_CRQ,
2148 				   vdev->unit_address,
2149 				   queue->msg_token, PAGE_SIZE);
2150 	rc = retrc;
2151 
2152 	if (rc == H_RESOURCE)
2153 		rc = ibmvmc_reset_crq_queue(adapter);
2154 
2155 	if (rc == 2) {
2156 		dev_warn(adapter->dev, "Partner adapter not ready\n");
2157 		retrc = 0;
2158 	} else if (rc != 0) {
2159 		dev_err(adapter->dev, "Error %d opening adapter\n", rc);
2160 		goto reg_crq_failed;
2161 	}
2162 
2163 	queue->cur = 0;
2164 	spin_lock_init(&queue->lock);
2165 
2166 	tasklet_init(&adapter->work_task, ibmvmc_task, (unsigned long)adapter);
2167 
2168 	if (request_irq(vdev->irq,
2169 			ibmvmc_handle_event,
2170 			0, "ibmvmc", (void *)adapter) != 0) {
2171 		dev_err(adapter->dev, "couldn't register irq 0x%x\n",
2172 			vdev->irq);
2173 		goto req_irq_failed;
2174 	}
2175 
2176 	rc = vio_enable_interrupts(vdev);
2177 	if (rc != 0) {
2178 		dev_err(adapter->dev, "Error %d enabling interrupts!!!\n", rc);
2179 		goto req_irq_failed;
2180 	}
2181 
2182 	return retrc;
2183 
2184 req_irq_failed:
2185 	/* Cannot have any work since we either never got our IRQ registered,
2186 	 * or never got interrupts enabled
2187 	 */
2188 	tasklet_kill(&adapter->work_task);
2189 	h_free_crq(vdev->unit_address);
2190 reg_crq_failed:
2191 	dma_unmap_single(adapter->dev,
2192 			 queue->msg_token,
2193 			 queue->size * sizeof(*queue->msgs), DMA_BIDIRECTIONAL);
2194 map_failed:
2195 	free_page((unsigned long)queue->msgs);
2196 malloc_failed:
2197 	return -ENOMEM;
2198 }
2199 
2200 /* Fill in the liobn and riobn fields on the adapter */
2201 static int read_dma_window(struct vio_dev *vdev,
2202 			   struct crq_server_adapter *adapter)
2203 {
2204 	const __be32 *dma_window;
2205 	const __be32 *prop;
2206 
2207 	/* TODO Using of_parse_dma_window would be better, but it doesn't give
2208 	 * a way to read multiple windows without already knowing the size of
2209 	 * a window or the number of windows
2210 	 */
2211 	dma_window =
2212 		(const __be32 *)vio_get_attribute(vdev, "ibm,my-dma-window",
2213 						NULL);
2214 	if (!dma_window) {
2215 		dev_warn(adapter->dev, "Couldn't find ibm,my-dma-window property\n");
2216 		return -1;
2217 	}
2218 
2219 	adapter->liobn = be32_to_cpu(*dma_window);
2220 	dma_window++;
2221 
2222 	prop = (const __be32 *)vio_get_attribute(vdev, "ibm,#dma-address-cells",
2223 						NULL);
2224 	if (!prop) {
2225 		dev_warn(adapter->dev, "Couldn't find ibm,#dma-address-cells property\n");
2226 		dma_window++;
2227 	} else {
2228 		dma_window += be32_to_cpu(*prop);
2229 	}
2230 
2231 	prop = (const __be32 *)vio_get_attribute(vdev, "ibm,#dma-size-cells",
2232 						NULL);
2233 	if (!prop) {
2234 		dev_warn(adapter->dev, "Couldn't find ibm,#dma-size-cells property\n");
2235 		dma_window++;
2236 	} else {
2237 		dma_window += be32_to_cpu(*prop);
2238 	}
2239 
2240 	/* dma_window should point to the second window now */
2241 	adapter->riobn = be32_to_cpu(*dma_window);
2242 
2243 	return 0;
2244 }
2245 
2246 static int ibmvmc_probe(struct vio_dev *vdev, const struct vio_device_id *id)
2247 {
2248 	struct crq_server_adapter *adapter = &ibmvmc_adapter;
2249 	int rc;
2250 
2251 	dev_set_drvdata(&vdev->dev, NULL);
2252 	memset(adapter, 0, sizeof(*adapter));
2253 	adapter->dev = &vdev->dev;
2254 
2255 	dev_info(adapter->dev, "Probe for UA 0x%x\n", vdev->unit_address);
2256 
2257 	rc = read_dma_window(vdev, adapter);
2258 	if (rc != 0) {
2259 		ibmvmc.state = ibmvmc_state_failed;
2260 		return -1;
2261 	}
2262 
2263 	dev_dbg(adapter->dev, "Probe: liobn 0x%x, riobn 0x%x\n",
2264 		adapter->liobn, adapter->riobn);
2265 
2266 	init_waitqueue_head(&adapter->reset_wait_queue);
2267 	adapter->reset_task = kthread_run(ibmvmc_reset_task, adapter, "ibmvmc");
2268 	if (IS_ERR(adapter->reset_task)) {
2269 		dev_err(adapter->dev, "Failed to start reset thread\n");
2270 		ibmvmc.state = ibmvmc_state_failed;
2271 		rc = PTR_ERR(adapter->reset_task);
2272 		adapter->reset_task = NULL;
2273 		return rc;
2274 	}
2275 
2276 	rc = ibmvmc_init_crq_queue(adapter);
2277 	if (rc != 0 && rc != H_RESOURCE) {
2278 		dev_err(adapter->dev, "Error initializing CRQ.  rc = 0x%x\n",
2279 			rc);
2280 		ibmvmc.state = ibmvmc_state_failed;
2281 		goto crq_failed;
2282 	}
2283 
2284 	ibmvmc.state = ibmvmc_state_crqinit;
2285 
2286 	/* Try to send an initialization message.  Note that this is allowed
2287 	 * to fail if the other end is not acive.  In that case we just wait
2288 	 * for the other side to initialize.
2289 	 */
2290 	if (ibmvmc_send_crq(adapter, 0xC001000000000000LL, 0) != 0 &&
2291 	    rc != H_RESOURCE)
2292 		dev_warn(adapter->dev, "Failed to send initialize CRQ message\n");
2293 
2294 	dev_set_drvdata(&vdev->dev, adapter);
2295 
2296 	return 0;
2297 
2298 crq_failed:
2299 	kthread_stop(adapter->reset_task);
2300 	adapter->reset_task = NULL;
2301 	return -EPERM;
2302 }
2303 
2304 static void ibmvmc_remove(struct vio_dev *vdev)
2305 {
2306 	struct crq_server_adapter *adapter = dev_get_drvdata(&vdev->dev);
2307 
2308 	dev_info(adapter->dev, "Entering remove for UA 0x%x\n",
2309 		 vdev->unit_address);
2310 	ibmvmc_release_crq_queue(adapter);
2311 }
2312 
2313 static struct vio_device_id ibmvmc_device_table[] = {
2314 	{ "ibm,vmc", "IBM,vmc" },
2315 	{ "", "" }
2316 };
2317 MODULE_DEVICE_TABLE(vio, ibmvmc_device_table);
2318 
2319 static struct vio_driver ibmvmc_driver = {
2320 	.name        = ibmvmc_driver_name,
2321 	.id_table    = ibmvmc_device_table,
2322 	.probe       = ibmvmc_probe,
2323 	.remove      = ibmvmc_remove,
2324 };
2325 
2326 static void __init ibmvmc_scrub_module_parms(void)
2327 {
2328 	if (ibmvmc_max_mtu > MAX_MTU) {
2329 		pr_warn("ibmvmc: Max MTU reduced to %d\n", MAX_MTU);
2330 		ibmvmc_max_mtu = MAX_MTU;
2331 	} else if (ibmvmc_max_mtu < MIN_MTU) {
2332 		pr_warn("ibmvmc: Max MTU increased to %d\n", MIN_MTU);
2333 		ibmvmc_max_mtu = MIN_MTU;
2334 	}
2335 
2336 	if (ibmvmc_max_buf_pool_size > MAX_BUF_POOL_SIZE) {
2337 		pr_warn("ibmvmc: Max buffer pool size reduced to %d\n",
2338 			MAX_BUF_POOL_SIZE);
2339 		ibmvmc_max_buf_pool_size = MAX_BUF_POOL_SIZE;
2340 	} else if (ibmvmc_max_buf_pool_size < MIN_BUF_POOL_SIZE) {
2341 		pr_warn("ibmvmc: Max buffer pool size increased to %d\n",
2342 			MIN_BUF_POOL_SIZE);
2343 		ibmvmc_max_buf_pool_size = MIN_BUF_POOL_SIZE;
2344 	}
2345 
2346 	if (ibmvmc_max_hmcs > MAX_HMCS) {
2347 		pr_warn("ibmvmc: Max HMCs reduced to %d\n", MAX_HMCS);
2348 		ibmvmc_max_hmcs = MAX_HMCS;
2349 	} else if (ibmvmc_max_hmcs < MIN_HMCS) {
2350 		pr_warn("ibmvmc: Max HMCs increased to %d\n", MIN_HMCS);
2351 		ibmvmc_max_hmcs = MIN_HMCS;
2352 	}
2353 }
2354 
2355 static struct miscdevice ibmvmc_miscdev = {
2356 	.name = ibmvmc_driver_name,
2357 	.minor = MISC_DYNAMIC_MINOR,
2358 	.fops = &ibmvmc_fops,
2359 };
2360 
2361 static int __init ibmvmc_module_init(void)
2362 {
2363 	int rc, i, j;
2364 
2365 	ibmvmc.state = ibmvmc_state_initial;
2366 	pr_info("ibmvmc: version %s\n", IBMVMC_DRIVER_VERSION);
2367 
2368 	rc = misc_register(&ibmvmc_miscdev);
2369 	if (rc) {
2370 		pr_err("ibmvmc: misc registration failed\n");
2371 		goto misc_register_failed;
2372 	}
2373 	pr_info("ibmvmc: node %d:%d\n", MISC_MAJOR,
2374 		ibmvmc_miscdev.minor);
2375 
2376 	/* Initialize data structures */
2377 	memset(hmcs, 0, sizeof(struct ibmvmc_hmc) * MAX_HMCS);
2378 	for (i = 0; i < MAX_HMCS; i++) {
2379 		spin_lock_init(&hmcs[i].lock);
2380 		hmcs[i].state = ibmhmc_state_free;
2381 		for (j = 0; j < MAX_BUF_POOL_SIZE; j++)
2382 			hmcs[i].queue_outbound_msgs[j] = VMC_INVALID_BUFFER_ID;
2383 	}
2384 
2385 	/* Sanity check module parms */
2386 	ibmvmc_scrub_module_parms();
2387 
2388 	/*
2389 	 * Initialize some reasonable values.  Might be negotiated smaller
2390 	 * values during the capabilities exchange.
2391 	 */
2392 	ibmvmc.max_mtu = ibmvmc_max_mtu;
2393 	ibmvmc.max_buffer_pool_size = ibmvmc_max_buf_pool_size;
2394 	ibmvmc.max_hmc_index = ibmvmc_max_hmcs - 1;
2395 
2396 	rc = vio_register_driver(&ibmvmc_driver);
2397 
2398 	if (rc) {
2399 		pr_err("ibmvmc: rc %d from vio_register_driver\n", rc);
2400 		goto vio_reg_failed;
2401 	}
2402 
2403 	return 0;
2404 
2405 vio_reg_failed:
2406 	misc_deregister(&ibmvmc_miscdev);
2407 misc_register_failed:
2408 	return rc;
2409 }
2410 
2411 static void __exit ibmvmc_module_exit(void)
2412 {
2413 	pr_info("ibmvmc: module exit\n");
2414 	vio_unregister_driver(&ibmvmc_driver);
2415 	misc_deregister(&ibmvmc_miscdev);
2416 }
2417 
2418 module_init(ibmvmc_module_init);
2419 module_exit(ibmvmc_module_exit);
2420 
2421 module_param_named(buf_pool_size, ibmvmc_max_buf_pool_size,
2422 		   int, 0644);
2423 MODULE_PARM_DESC(buf_pool_size, "Buffer pool size");
2424 module_param_named(max_hmcs, ibmvmc_max_hmcs, int, 0644);
2425 MODULE_PARM_DESC(max_hmcs, "Max HMCs");
2426 module_param_named(max_mtu, ibmvmc_max_mtu, int, 0644);
2427 MODULE_PARM_DESC(max_mtu, "Max MTU");
2428 
2429 MODULE_AUTHOR("Steven Royer <seroyer@linux.vnet.ibm.com>");
2430 MODULE_DESCRIPTION("IBM VMC");
2431 MODULE_VERSION(IBMVMC_DRIVER_VERSION);
2432 MODULE_LICENSE("GPL v2");
2433