1 // SPDX-License-Identifier: GPL-2.0 OR MIT
2 /*
3  * Copyright 2016 VMware, Inc., Palo Alto, CA., USA
4  *
5  * Permission is hereby granted, free of charge, to any person obtaining a
6  * copy of this software and associated documentation files (the
7  * "Software"), to deal in the Software without restriction, including
8  * without limitation the rights to use, copy, modify, merge, publish,
9  * distribute, sub license, and/or sell copies of the Software, and to
10  * permit persons to whom the Software is furnished to do so, subject to
11  * the following conditions:
12  *
13  * The above copyright notice and this permission notice (including the
14  * next paragraph) shall be included in all copies or substantial portions
15  * of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
20  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
21  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
22  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
23  * USE OR OTHER DEALINGS IN THE SOFTWARE.
24  *
25  */
26 
27 
28 #include <linux/slab.h>
29 #include <linux/module.h>
30 #include <linux/kernel.h>
31 #include <linux/frame.h>
32 #include <asm/hypervisor.h>
33 #include <drm/drmP.h>
34 #include "vmwgfx_drv.h"
35 #include "vmwgfx_msg.h"
36 
37 
38 #define MESSAGE_STATUS_SUCCESS  0x0001
39 #define MESSAGE_STATUS_DORECV   0x0002
40 #define MESSAGE_STATUS_CPT      0x0010
41 #define MESSAGE_STATUS_HB       0x0080
42 
43 #define RPCI_PROTOCOL_NUM       0x49435052
44 #define GUESTMSG_FLAG_COOKIE    0x80000000
45 
46 #define RETRIES                 3
47 
48 #define VMW_HYPERVISOR_MAGIC    0x564D5868
49 #define VMW_HYPERVISOR_PORT     0x5658
50 #define VMW_HYPERVISOR_HB_PORT  0x5659
51 
52 #define VMW_PORT_CMD_MSG        30
53 #define VMW_PORT_CMD_HB_MSG     0
54 #define VMW_PORT_CMD_OPEN_CHANNEL  (MSG_TYPE_OPEN << 16 | VMW_PORT_CMD_MSG)
55 #define VMW_PORT_CMD_CLOSE_CHANNEL (MSG_TYPE_CLOSE << 16 | VMW_PORT_CMD_MSG)
56 #define VMW_PORT_CMD_SENDSIZE   (MSG_TYPE_SENDSIZE << 16 | VMW_PORT_CMD_MSG)
57 #define VMW_PORT_CMD_RECVSIZE   (MSG_TYPE_RECVSIZE << 16 | VMW_PORT_CMD_MSG)
58 #define VMW_PORT_CMD_RECVSTATUS (MSG_TYPE_RECVSTATUS << 16 | VMW_PORT_CMD_MSG)
59 
60 #define HIGH_WORD(X) ((X & 0xFFFF0000) >> 16)
61 
62 static u32 vmw_msg_enabled = 1;
63 
64 enum rpc_msg_type {
65 	MSG_TYPE_OPEN,
66 	MSG_TYPE_SENDSIZE,
67 	MSG_TYPE_SENDPAYLOAD,
68 	MSG_TYPE_RECVSIZE,
69 	MSG_TYPE_RECVPAYLOAD,
70 	MSG_TYPE_RECVSTATUS,
71 	MSG_TYPE_CLOSE,
72 };
73 
74 struct rpc_channel {
75 	u16 channel_id;
76 	u32 cookie_high;
77 	u32 cookie_low;
78 };
79 
80 
81 
82 /**
83  * vmw_open_channel
84  *
85  * @channel: RPC channel
86  * @protocol:
87  *
88  * Returns: 0 on success
89  */
90 static int vmw_open_channel(struct rpc_channel *channel, unsigned int protocol)
91 {
92 	unsigned long eax, ebx, ecx, edx, si = 0, di = 0;
93 
94 	VMW_PORT(VMW_PORT_CMD_OPEN_CHANNEL,
95 		(protocol | GUESTMSG_FLAG_COOKIE), si, di,
96 		VMW_HYPERVISOR_PORT,
97 		VMW_HYPERVISOR_MAGIC,
98 		eax, ebx, ecx, edx, si, di);
99 
100 	if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0)
101 		return -EINVAL;
102 
103 	channel->channel_id  = HIGH_WORD(edx);
104 	channel->cookie_high = si;
105 	channel->cookie_low  = di;
106 
107 	return 0;
108 }
109 
110 
111 
112 /**
113  * vmw_close_channel
114  *
115  * @channel: RPC channel
116  *
117  * Returns: 0 on success
118  */
119 static int vmw_close_channel(struct rpc_channel *channel)
120 {
121 	unsigned long eax, ebx, ecx, edx, si, di;
122 
123 	/* Set up additional parameters */
124 	si  = channel->cookie_high;
125 	di  = channel->cookie_low;
126 
127 	VMW_PORT(VMW_PORT_CMD_CLOSE_CHANNEL,
128 		0, si, di,
129 		(VMW_HYPERVISOR_PORT | (channel->channel_id << 16)),
130 		VMW_HYPERVISOR_MAGIC,
131 		eax, ebx, ecx, edx, si, di);
132 
133 	if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0)
134 		return -EINVAL;
135 
136 	return 0;
137 }
138 
139 /**
140  * vmw_port_hb_out - Send the message payload either through the
141  * high-bandwidth port if available, or through the backdoor otherwise.
142  * @channel: The rpc channel.
143  * @msg: NULL-terminated message.
144  * @hb: Whether the high-bandwidth port is available.
145  *
146  * Return: The port status.
147  */
148 static unsigned long vmw_port_hb_out(struct rpc_channel *channel,
149 				     const char *msg, bool hb)
150 {
151 	unsigned long si, di, eax, ebx, ecx, edx;
152 	unsigned long msg_len = strlen(msg);
153 
154 	if (hb) {
155 		unsigned long bp = channel->cookie_high;
156 
157 		si = (uintptr_t) msg;
158 		di = channel->cookie_low;
159 
160 		VMW_PORT_HB_OUT(
161 			(MESSAGE_STATUS_SUCCESS << 16) | VMW_PORT_CMD_HB_MSG,
162 			msg_len, si, di,
163 			VMW_HYPERVISOR_HB_PORT | (channel->channel_id << 16),
164 			VMW_HYPERVISOR_MAGIC, bp,
165 			eax, ebx, ecx, edx, si, di);
166 
167 		return ebx;
168 	}
169 
170 	/* HB port not available. Send the message 4 bytes at a time. */
171 	ecx = MESSAGE_STATUS_SUCCESS << 16;
172 	while (msg_len && (HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS)) {
173 		unsigned int bytes = min_t(size_t, msg_len, 4);
174 		unsigned long word = 0;
175 
176 		memcpy(&word, msg, bytes);
177 		msg_len -= bytes;
178 		msg += bytes;
179 		si = channel->cookie_high;
180 		di = channel->cookie_low;
181 
182 		VMW_PORT(VMW_PORT_CMD_MSG | (MSG_TYPE_SENDPAYLOAD << 16),
183 			 word, si, di,
184 			 VMW_HYPERVISOR_PORT | (channel->channel_id << 16),
185 			 VMW_HYPERVISOR_MAGIC,
186 			 eax, ebx, ecx, edx, si, di);
187 	}
188 
189 	return ecx;
190 }
191 
192 /**
193  * vmw_port_hb_in - Receive the message payload either through the
194  * high-bandwidth port if available, or through the backdoor otherwise.
195  * @channel: The rpc channel.
196  * @reply: Pointer to buffer holding reply.
197  * @reply_len: Length of the reply.
198  * @hb: Whether the high-bandwidth port is available.
199  *
200  * Return: The port status.
201  */
202 static unsigned long vmw_port_hb_in(struct rpc_channel *channel, char *reply,
203 				    unsigned long reply_len, bool hb)
204 {
205 	unsigned long si, di, eax, ebx, ecx, edx;
206 
207 	if (hb) {
208 		unsigned long bp = channel->cookie_low;
209 
210 		si = channel->cookie_high;
211 		di = (uintptr_t) reply;
212 
213 		VMW_PORT_HB_IN(
214 			(MESSAGE_STATUS_SUCCESS << 16) | VMW_PORT_CMD_HB_MSG,
215 			reply_len, si, di,
216 			VMW_HYPERVISOR_HB_PORT | (channel->channel_id << 16),
217 			VMW_HYPERVISOR_MAGIC, bp,
218 			eax, ebx, ecx, edx, si, di);
219 
220 		return ebx;
221 	}
222 
223 	/* HB port not available. Retrieve the message 4 bytes at a time. */
224 	ecx = MESSAGE_STATUS_SUCCESS << 16;
225 	while (reply_len) {
226 		unsigned int bytes = min_t(unsigned long, reply_len, 4);
227 
228 		si = channel->cookie_high;
229 		di = channel->cookie_low;
230 
231 		VMW_PORT(VMW_PORT_CMD_MSG | (MSG_TYPE_RECVPAYLOAD << 16),
232 			 MESSAGE_STATUS_SUCCESS, si, di,
233 			 VMW_HYPERVISOR_PORT | (channel->channel_id << 16),
234 			 VMW_HYPERVISOR_MAGIC,
235 			 eax, ebx, ecx, edx, si, di);
236 
237 		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0)
238 			break;
239 
240 		memcpy(reply, &ebx, bytes);
241 		reply_len -= bytes;
242 		reply += bytes;
243 	}
244 
245 	return ecx;
246 }
247 
248 
249 /**
250  * vmw_send_msg: Sends a message to the host
251  *
252  * @channel: RPC channel
253  * @logmsg: NULL terminated string
254  *
255  * Returns: 0 on success
256  */
257 static int vmw_send_msg(struct rpc_channel *channel, const char *msg)
258 {
259 	unsigned long eax, ebx, ecx, edx, si, di;
260 	size_t msg_len = strlen(msg);
261 	int retries = 0;
262 
263 	while (retries < RETRIES) {
264 		retries++;
265 
266 		/* Set up additional parameters */
267 		si  = channel->cookie_high;
268 		di  = channel->cookie_low;
269 
270 		VMW_PORT(VMW_PORT_CMD_SENDSIZE,
271 			msg_len, si, di,
272 			VMW_HYPERVISOR_PORT | (channel->channel_id << 16),
273 			VMW_HYPERVISOR_MAGIC,
274 			eax, ebx, ecx, edx, si, di);
275 
276 		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0) {
277 			/* Expected success. Give up. */
278 			return -EINVAL;
279 		}
280 
281 		/* Send msg */
282 		ebx = vmw_port_hb_out(channel, msg,
283 				      !!(HIGH_WORD(ecx) & MESSAGE_STATUS_HB));
284 
285 		if ((HIGH_WORD(ebx) & MESSAGE_STATUS_SUCCESS) != 0) {
286 			return 0;
287 		} else if ((HIGH_WORD(ebx) & MESSAGE_STATUS_CPT) != 0) {
288 			/* A checkpoint occurred. Retry. */
289 			continue;
290 		} else {
291 			break;
292 		}
293 	}
294 
295 	return -EINVAL;
296 }
297 STACK_FRAME_NON_STANDARD(vmw_send_msg);
298 
299 
300 /**
301  * vmw_recv_msg: Receives a message from the host
302  *
303  * Note:  It is the caller's responsibility to call kfree() on msg.
304  *
305  * @channel:  channel opened by vmw_open_channel
306  * @msg:  [OUT] message received from the host
307  * @msg_len: message length
308  */
309 static int vmw_recv_msg(struct rpc_channel *channel, void **msg,
310 			size_t *msg_len)
311 {
312 	unsigned long eax, ebx, ecx, edx, si, di;
313 	char *reply;
314 	size_t reply_len;
315 	int retries = 0;
316 
317 
318 	*msg_len = 0;
319 	*msg = NULL;
320 
321 	while (retries < RETRIES) {
322 		retries++;
323 
324 		/* Set up additional parameters */
325 		si  = channel->cookie_high;
326 		di  = channel->cookie_low;
327 
328 		VMW_PORT(VMW_PORT_CMD_RECVSIZE,
329 			0, si, di,
330 			(VMW_HYPERVISOR_PORT | (channel->channel_id << 16)),
331 			VMW_HYPERVISOR_MAGIC,
332 			eax, ebx, ecx, edx, si, di);
333 
334 		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0) {
335 			DRM_ERROR("Failed to get reply size for host message.\n");
336 			return -EINVAL;
337 		}
338 
339 		/* No reply available.  This is okay. */
340 		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_DORECV) == 0)
341 			return 0;
342 
343 		reply_len = ebx;
344 		reply     = kzalloc(reply_len + 1, GFP_KERNEL);
345 		if (!reply) {
346 			DRM_ERROR("Cannot allocate memory for host message reply.\n");
347 			return -ENOMEM;
348 		}
349 
350 
351 		/* Receive buffer */
352 		ebx = vmw_port_hb_in(channel, reply, reply_len,
353 				     !!(HIGH_WORD(ecx) & MESSAGE_STATUS_HB));
354 		if ((HIGH_WORD(ebx) & MESSAGE_STATUS_SUCCESS) == 0) {
355 			kfree(reply);
356 
357 			if ((HIGH_WORD(ebx) & MESSAGE_STATUS_CPT) != 0) {
358 				/* A checkpoint occurred. Retry. */
359 				continue;
360 			}
361 
362 			return -EINVAL;
363 		}
364 
365 		reply[reply_len] = '\0';
366 
367 
368 		/* Ack buffer */
369 		si  = channel->cookie_high;
370 		di  = channel->cookie_low;
371 
372 		VMW_PORT(VMW_PORT_CMD_RECVSTATUS,
373 			MESSAGE_STATUS_SUCCESS, si, di,
374 			(VMW_HYPERVISOR_PORT | (channel->channel_id << 16)),
375 			VMW_HYPERVISOR_MAGIC,
376 			eax, ebx, ecx, edx, si, di);
377 
378 		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0) {
379 			kfree(reply);
380 
381 			if ((HIGH_WORD(ecx) & MESSAGE_STATUS_CPT) != 0) {
382 				/* A checkpoint occurred. Retry. */
383 				continue;
384 			}
385 
386 			return -EINVAL;
387 		}
388 
389 		break;
390 	}
391 
392 	if (retries == RETRIES) {
393 		kfree(reply);
394 		return -EINVAL;
395 	}
396 
397 	*msg_len = reply_len;
398 	*msg     = reply;
399 
400 	return 0;
401 }
402 STACK_FRAME_NON_STANDARD(vmw_recv_msg);
403 
404 
405 /**
406  * vmw_host_get_guestinfo: Gets a GuestInfo parameter
407  *
408  * Gets the value of a  GuestInfo.* parameter.  The value returned will be in
409  * a string, and it is up to the caller to post-process.
410  *
411  * @guest_info_param:  Parameter to get, e.g. GuestInfo.svga.gl3
412  * @buffer: if NULL, *reply_len will contain reply size.
413  * @length: size of the reply_buf.  Set to size of reply upon return
414  *
415  * Returns: 0 on success
416  */
417 int vmw_host_get_guestinfo(const char *guest_info_param,
418 			   char *buffer, size_t *length)
419 {
420 	struct rpc_channel channel;
421 	char *msg, *reply = NULL;
422 	size_t reply_len = 0;
423 
424 	if (!vmw_msg_enabled)
425 		return -ENODEV;
426 
427 	if (!guest_info_param || !length)
428 		return -EINVAL;
429 
430 	msg = kasprintf(GFP_KERNEL, "info-get %s", guest_info_param);
431 	if (!msg) {
432 		DRM_ERROR("Cannot allocate memory to get guest info \"%s\".",
433 			  guest_info_param);
434 		return -ENOMEM;
435 	}
436 
437 	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM))
438 		goto out_open;
439 
440 	if (vmw_send_msg(&channel, msg) ||
441 	    vmw_recv_msg(&channel, (void *) &reply, &reply_len))
442 		goto out_msg;
443 
444 	vmw_close_channel(&channel);
445 	if (buffer && reply && reply_len > 0) {
446 		/* Remove reply code, which are the first 2 characters of
447 		 * the reply
448 		 */
449 		reply_len = max(reply_len - 2, (size_t) 0);
450 		reply_len = min(reply_len, *length);
451 
452 		if (reply_len > 0)
453 			memcpy(buffer, reply + 2, reply_len);
454 	}
455 
456 	*length = reply_len;
457 
458 	kfree(reply);
459 	kfree(msg);
460 
461 	return 0;
462 
463 out_msg:
464 	vmw_close_channel(&channel);
465 	kfree(reply);
466 out_open:
467 	*length = 0;
468 	kfree(msg);
469 	DRM_ERROR("Failed to get guest info \"%s\".", guest_info_param);
470 
471 	return -EINVAL;
472 }
473 
474 
475 
476 /**
477  * vmw_host_log: Sends a log message to the host
478  *
479  * @log: NULL terminated string
480  *
481  * Returns: 0 on success
482  */
483 int vmw_host_log(const char *log)
484 {
485 	struct rpc_channel channel;
486 	char *msg;
487 	int ret = 0;
488 
489 
490 	if (!vmw_msg_enabled)
491 		return -ENODEV;
492 
493 	if (!log)
494 		return ret;
495 
496 	msg = kasprintf(GFP_KERNEL, "log %s", log);
497 	if (!msg) {
498 		DRM_ERROR("Cannot allocate memory for host log message.\n");
499 		return -ENOMEM;
500 	}
501 
502 	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM))
503 		goto out_open;
504 
505 	if (vmw_send_msg(&channel, msg))
506 		goto out_msg;
507 
508 	vmw_close_channel(&channel);
509 	kfree(msg);
510 
511 	return 0;
512 
513 out_msg:
514 	vmw_close_channel(&channel);
515 out_open:
516 	kfree(msg);
517 	DRM_ERROR("Failed to send host log message.\n");
518 
519 	return -EINVAL;
520 }
521