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 
50 #define VMW_PORT_CMD_MSG        30
51 #define VMW_PORT_CMD_HB_MSG     0
52 #define VMW_PORT_CMD_OPEN_CHANNEL  (MSG_TYPE_OPEN << 16 | VMW_PORT_CMD_MSG)
53 #define VMW_PORT_CMD_CLOSE_CHANNEL (MSG_TYPE_CLOSE << 16 | VMW_PORT_CMD_MSG)
54 #define VMW_PORT_CMD_SENDSIZE   (MSG_TYPE_SENDSIZE << 16 | VMW_PORT_CMD_MSG)
55 #define VMW_PORT_CMD_RECVSIZE   (MSG_TYPE_RECVSIZE << 16 | VMW_PORT_CMD_MSG)
56 #define VMW_PORT_CMD_RECVSTATUS (MSG_TYPE_RECVSTATUS << 16 | VMW_PORT_CMD_MSG)
57 
58 #define HIGH_WORD(X) ((X & 0xFFFF0000) >> 16)
59 
60 static u32 vmw_msg_enabled = 1;
61 
62 enum rpc_msg_type {
63 	MSG_TYPE_OPEN,
64 	MSG_TYPE_SENDSIZE,
65 	MSG_TYPE_SENDPAYLOAD,
66 	MSG_TYPE_RECVSIZE,
67 	MSG_TYPE_RECVPAYLOAD,
68 	MSG_TYPE_RECVSTATUS,
69 	MSG_TYPE_CLOSE,
70 };
71 
72 struct rpc_channel {
73 	u16 channel_id;
74 	u32 cookie_high;
75 	u32 cookie_low;
76 };
77 
78 
79 
80 /**
81  * vmw_open_channel
82  *
83  * @channel: RPC channel
84  * @protocol:
85  *
86  * Returns: 0 on success
87  */
88 static int vmw_open_channel(struct rpc_channel *channel, unsigned int protocol)
89 {
90 	unsigned long eax, ebx, ecx, edx, si = 0, di = 0;
91 
92 	VMW_PORT(VMW_PORT_CMD_OPEN_CHANNEL,
93 		(protocol | GUESTMSG_FLAG_COOKIE), si, di,
94 		0,
95 		VMW_HYPERVISOR_MAGIC,
96 		eax, ebx, ecx, edx, si, di);
97 
98 	if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0)
99 		return -EINVAL;
100 
101 	channel->channel_id  = HIGH_WORD(edx);
102 	channel->cookie_high = si;
103 	channel->cookie_low  = di;
104 
105 	return 0;
106 }
107 
108 
109 
110 /**
111  * vmw_close_channel
112  *
113  * @channel: RPC channel
114  *
115  * Returns: 0 on success
116  */
117 static int vmw_close_channel(struct rpc_channel *channel)
118 {
119 	unsigned long eax, ebx, ecx, edx, si, di;
120 
121 	/* Set up additional parameters */
122 	si  = channel->cookie_high;
123 	di  = channel->cookie_low;
124 
125 	VMW_PORT(VMW_PORT_CMD_CLOSE_CHANNEL,
126 		0, si, di,
127 		channel->channel_id << 16,
128 		VMW_HYPERVISOR_MAGIC,
129 		eax, ebx, ecx, edx, si, di);
130 
131 	if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0)
132 		return -EINVAL;
133 
134 	return 0;
135 }
136 
137 /**
138  * vmw_port_hb_out - Send the message payload either through the
139  * high-bandwidth port if available, or through the backdoor otherwise.
140  * @channel: The rpc channel.
141  * @msg: NULL-terminated message.
142  * @hb: Whether the high-bandwidth port is available.
143  *
144  * Return: The port status.
145  */
146 static unsigned long vmw_port_hb_out(struct rpc_channel *channel,
147 				     const char *msg, bool hb)
148 {
149 	unsigned long si, di, eax, ebx, ecx, edx;
150 	unsigned long msg_len = strlen(msg);
151 
152 	if (hb) {
153 		unsigned long bp = channel->cookie_high;
154 
155 		si = (uintptr_t) msg;
156 		di = channel->cookie_low;
157 
158 		VMW_PORT_HB_OUT(
159 			(MESSAGE_STATUS_SUCCESS << 16) | VMW_PORT_CMD_HB_MSG,
160 			msg_len, si, di,
161 			VMWARE_HYPERVISOR_HB | (channel->channel_id << 16) |
162 			VMWARE_HYPERVISOR_OUT,
163 			VMW_HYPERVISOR_MAGIC, bp,
164 			eax, ebx, ecx, edx, si, di);
165 
166 		return ebx;
167 	}
168 
169 	/* HB port not available. Send the message 4 bytes at a time. */
170 	ecx = MESSAGE_STATUS_SUCCESS << 16;
171 	while (msg_len && (HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS)) {
172 		unsigned int bytes = min_t(size_t, msg_len, 4);
173 		unsigned long word = 0;
174 
175 		memcpy(&word, msg, bytes);
176 		msg_len -= bytes;
177 		msg += bytes;
178 		si = channel->cookie_high;
179 		di = channel->cookie_low;
180 
181 		VMW_PORT(VMW_PORT_CMD_MSG | (MSG_TYPE_SENDPAYLOAD << 16),
182 			 word, si, di,
183 			 channel->channel_id << 16,
184 			 VMW_HYPERVISOR_MAGIC,
185 			 eax, ebx, ecx, edx, si, di);
186 	}
187 
188 	return ecx;
189 }
190 
191 /**
192  * vmw_port_hb_in - Receive the message payload either through the
193  * high-bandwidth port if available, or through the backdoor otherwise.
194  * @channel: The rpc channel.
195  * @reply: Pointer to buffer holding reply.
196  * @reply_len: Length of the reply.
197  * @hb: Whether the high-bandwidth port is available.
198  *
199  * Return: The port status.
200  */
201 static unsigned long vmw_port_hb_in(struct rpc_channel *channel, char *reply,
202 				    unsigned long reply_len, bool hb)
203 {
204 	unsigned long si, di, eax, ebx, ecx, edx;
205 
206 	if (hb) {
207 		unsigned long bp = channel->cookie_low;
208 
209 		si = channel->cookie_high;
210 		di = (uintptr_t) reply;
211 
212 		VMW_PORT_HB_IN(
213 			(MESSAGE_STATUS_SUCCESS << 16) | VMW_PORT_CMD_HB_MSG,
214 			reply_len, si, di,
215 			VMWARE_HYPERVISOR_HB | (channel->channel_id << 16),
216 			VMW_HYPERVISOR_MAGIC, bp,
217 			eax, ebx, ecx, edx, si, di);
218 
219 		return ebx;
220 	}
221 
222 	/* HB port not available. Retrieve the message 4 bytes at a time. */
223 	ecx = MESSAGE_STATUS_SUCCESS << 16;
224 	while (reply_len) {
225 		unsigned int bytes = min_t(unsigned long, reply_len, 4);
226 
227 		si = channel->cookie_high;
228 		di = channel->cookie_low;
229 
230 		VMW_PORT(VMW_PORT_CMD_MSG | (MSG_TYPE_RECVPAYLOAD << 16),
231 			 MESSAGE_STATUS_SUCCESS, si, di,
232 			 channel->channel_id << 16,
233 			 VMW_HYPERVISOR_MAGIC,
234 			 eax, ebx, ecx, edx, si, di);
235 
236 		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0)
237 			break;
238 
239 		memcpy(reply, &ebx, bytes);
240 		reply_len -= bytes;
241 		reply += bytes;
242 	}
243 
244 	return ecx;
245 }
246 
247 
248 /**
249  * vmw_send_msg: Sends a message to the host
250  *
251  * @channel: RPC channel
252  * @logmsg: NULL terminated string
253  *
254  * Returns: 0 on success
255  */
256 static int vmw_send_msg(struct rpc_channel *channel, const char *msg)
257 {
258 	unsigned long eax, ebx, ecx, edx, si, di;
259 	size_t msg_len = strlen(msg);
260 	int retries = 0;
261 
262 	while (retries < RETRIES) {
263 		retries++;
264 
265 		/* Set up additional parameters */
266 		si  = channel->cookie_high;
267 		di  = channel->cookie_low;
268 
269 		VMW_PORT(VMW_PORT_CMD_SENDSIZE,
270 			msg_len, si, di,
271 			channel->channel_id << 16,
272 			VMW_HYPERVISOR_MAGIC,
273 			eax, ebx, ecx, edx, si, di);
274 
275 		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0) {
276 			/* Expected success. Give up. */
277 			return -EINVAL;
278 		}
279 
280 		/* Send msg */
281 		ebx = vmw_port_hb_out(channel, msg,
282 				      !!(HIGH_WORD(ecx) & MESSAGE_STATUS_HB));
283 
284 		if ((HIGH_WORD(ebx) & MESSAGE_STATUS_SUCCESS) != 0) {
285 			return 0;
286 		} else if ((HIGH_WORD(ebx) & MESSAGE_STATUS_CPT) != 0) {
287 			/* A checkpoint occurred. Retry. */
288 			continue;
289 		} else {
290 			break;
291 		}
292 	}
293 
294 	return -EINVAL;
295 }
296 STACK_FRAME_NON_STANDARD(vmw_send_msg);
297 
298 
299 /**
300  * vmw_recv_msg: Receives a message from the host
301  *
302  * Note:  It is the caller's responsibility to call kfree() on msg.
303  *
304  * @channel:  channel opened by vmw_open_channel
305  * @msg:  [OUT] message received from the host
306  * @msg_len: message length
307  */
308 static int vmw_recv_msg(struct rpc_channel *channel, void **msg,
309 			size_t *msg_len)
310 {
311 	unsigned long eax, ebx, ecx, edx, si, di;
312 	char *reply;
313 	size_t reply_len;
314 	int retries = 0;
315 
316 
317 	*msg_len = 0;
318 	*msg = NULL;
319 
320 	while (retries < RETRIES) {
321 		retries++;
322 
323 		/* Set up additional parameters */
324 		si  = channel->cookie_high;
325 		di  = channel->cookie_low;
326 
327 		VMW_PORT(VMW_PORT_CMD_RECVSIZE,
328 			0, si, di,
329 			channel->channel_id << 16,
330 			VMW_HYPERVISOR_MAGIC,
331 			eax, ebx, ecx, edx, si, di);
332 
333 		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0) {
334 			DRM_ERROR("Failed to get reply size for host message.\n");
335 			return -EINVAL;
336 		}
337 
338 		/* No reply available.  This is okay. */
339 		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_DORECV) == 0)
340 			return 0;
341 
342 		reply_len = ebx;
343 		reply     = kzalloc(reply_len + 1, GFP_KERNEL);
344 		if (!reply) {
345 			DRM_ERROR("Cannot allocate memory for host message reply.\n");
346 			return -ENOMEM;
347 		}
348 
349 
350 		/* Receive buffer */
351 		ebx = vmw_port_hb_in(channel, reply, reply_len,
352 				     !!(HIGH_WORD(ecx) & MESSAGE_STATUS_HB));
353 		if ((HIGH_WORD(ebx) & MESSAGE_STATUS_SUCCESS) == 0) {
354 			kfree(reply);
355 			reply = NULL;
356 			if ((HIGH_WORD(ebx) & MESSAGE_STATUS_CPT) != 0) {
357 				/* A checkpoint occurred. Retry. */
358 				continue;
359 			}
360 
361 			return -EINVAL;
362 		}
363 
364 		reply[reply_len] = '\0';
365 
366 
367 		/* Ack buffer */
368 		si  = channel->cookie_high;
369 		di  = channel->cookie_low;
370 
371 		VMW_PORT(VMW_PORT_CMD_RECVSTATUS,
372 			MESSAGE_STATUS_SUCCESS, si, di,
373 			channel->channel_id << 16,
374 			VMW_HYPERVISOR_MAGIC,
375 			eax, ebx, ecx, edx, si, di);
376 
377 		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0) {
378 			kfree(reply);
379 			reply = NULL;
380 			if ((HIGH_WORD(ecx) & MESSAGE_STATUS_CPT) != 0) {
381 				/* A checkpoint occurred. Retry. */
382 				continue;
383 			}
384 
385 			return -EINVAL;
386 		}
387 
388 		break;
389 	}
390 
391 	if (!reply)
392 		return -EINVAL;
393 
394 	*msg_len = reply_len;
395 	*msg     = reply;
396 
397 	return 0;
398 }
399 STACK_FRAME_NON_STANDARD(vmw_recv_msg);
400 
401 
402 /**
403  * vmw_host_get_guestinfo: Gets a GuestInfo parameter
404  *
405  * Gets the value of a  GuestInfo.* parameter.  The value returned will be in
406  * a string, and it is up to the caller to post-process.
407  *
408  * @guest_info_param:  Parameter to get, e.g. GuestInfo.svga.gl3
409  * @buffer: if NULL, *reply_len will contain reply size.
410  * @length: size of the reply_buf.  Set to size of reply upon return
411  *
412  * Returns: 0 on success
413  */
414 int vmw_host_get_guestinfo(const char *guest_info_param,
415 			   char *buffer, size_t *length)
416 {
417 	struct rpc_channel channel;
418 	char *msg, *reply = NULL;
419 	size_t reply_len = 0;
420 
421 	if (!vmw_msg_enabled)
422 		return -ENODEV;
423 
424 	if (!guest_info_param || !length)
425 		return -EINVAL;
426 
427 	msg = kasprintf(GFP_KERNEL, "info-get %s", guest_info_param);
428 	if (!msg) {
429 		DRM_ERROR("Cannot allocate memory to get guest info \"%s\".",
430 			  guest_info_param);
431 		return -ENOMEM;
432 	}
433 
434 	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM))
435 		goto out_open;
436 
437 	if (vmw_send_msg(&channel, msg) ||
438 	    vmw_recv_msg(&channel, (void *) &reply, &reply_len))
439 		goto out_msg;
440 
441 	vmw_close_channel(&channel);
442 	if (buffer && reply && reply_len > 0) {
443 		/* Remove reply code, which are the first 2 characters of
444 		 * the reply
445 		 */
446 		reply_len = max(reply_len - 2, (size_t) 0);
447 		reply_len = min(reply_len, *length);
448 
449 		if (reply_len > 0)
450 			memcpy(buffer, reply + 2, reply_len);
451 	}
452 
453 	*length = reply_len;
454 
455 	kfree(reply);
456 	kfree(msg);
457 
458 	return 0;
459 
460 out_msg:
461 	vmw_close_channel(&channel);
462 	kfree(reply);
463 out_open:
464 	*length = 0;
465 	kfree(msg);
466 	DRM_ERROR("Failed to get guest info \"%s\".", guest_info_param);
467 
468 	return -EINVAL;
469 }
470 
471 
472 
473 /**
474  * vmw_host_log: Sends a log message to the host
475  *
476  * @log: NULL terminated string
477  *
478  * Returns: 0 on success
479  */
480 int vmw_host_log(const char *log)
481 {
482 	struct rpc_channel channel;
483 	char *msg;
484 	int ret = 0;
485 
486 
487 	if (!vmw_msg_enabled)
488 		return -ENODEV;
489 
490 	if (!log)
491 		return ret;
492 
493 	msg = kasprintf(GFP_KERNEL, "log %s", log);
494 	if (!msg) {
495 		DRM_ERROR("Cannot allocate memory for host log message.\n");
496 		return -ENOMEM;
497 	}
498 
499 	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM))
500 		goto out_open;
501 
502 	if (vmw_send_msg(&channel, msg))
503 		goto out_msg;
504 
505 	vmw_close_channel(&channel);
506 	kfree(msg);
507 
508 	return 0;
509 
510 out_msg:
511 	vmw_close_channel(&channel);
512 out_open:
513 	kfree(msg);
514 	DRM_ERROR("Failed to send host log message.\n");
515 
516 	return -EINVAL;
517 }
518