1 /*
2  * Copyright © 2016 VMware, Inc., Palo Alto, CA., USA
3  * All Rights Reserved.
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_msg.h"
35 
36 
37 #define MESSAGE_STATUS_SUCCESS  0x0001
38 #define MESSAGE_STATUS_DORECV   0x0002
39 #define MESSAGE_STATUS_CPT      0x0010
40 #define MESSAGE_STATUS_HB       0x0080
41 
42 #define RPCI_PROTOCOL_NUM       0x49435052
43 #define GUESTMSG_FLAG_COOKIE    0x80000000
44 
45 #define RETRIES                 3
46 
47 #define VMW_HYPERVISOR_MAGIC    0x564D5868
48 #define VMW_HYPERVISOR_PORT     0x5658
49 #define VMW_HYPERVISOR_HB_PORT  0x5659
50 
51 #define VMW_PORT_CMD_MSG        30
52 #define VMW_PORT_CMD_HB_MSG     0
53 #define VMW_PORT_CMD_OPEN_CHANNEL  (MSG_TYPE_OPEN << 16 | VMW_PORT_CMD_MSG)
54 #define VMW_PORT_CMD_CLOSE_CHANNEL (MSG_TYPE_CLOSE << 16 | VMW_PORT_CMD_MSG)
55 #define VMW_PORT_CMD_SENDSIZE   (MSG_TYPE_SENDSIZE << 16 | VMW_PORT_CMD_MSG)
56 #define VMW_PORT_CMD_RECVSIZE   (MSG_TYPE_RECVSIZE << 16 | VMW_PORT_CMD_MSG)
57 #define VMW_PORT_CMD_RECVSTATUS (MSG_TYPE_RECVSTATUS << 16 | VMW_PORT_CMD_MSG)
58 
59 #define HIGH_WORD(X) ((X & 0xFFFF0000) >> 16)
60 
61 static u32 vmw_msg_enabled = 1;
62 
63 enum rpc_msg_type {
64 	MSG_TYPE_OPEN,
65 	MSG_TYPE_SENDSIZE,
66 	MSG_TYPE_SENDPAYLOAD,
67 	MSG_TYPE_RECVSIZE,
68 	MSG_TYPE_RECVPAYLOAD,
69 	MSG_TYPE_RECVSTATUS,
70 	MSG_TYPE_CLOSE,
71 };
72 
73 struct rpc_channel {
74 	u16 channel_id;
75 	u32 cookie_high;
76 	u32 cookie_low;
77 };
78 
79 
80 
81 /**
82  * vmw_open_channel
83  *
84  * @channel: RPC channel
85  * @protocol:
86  *
87  * Returns: 0 on success
88  */
89 static int vmw_open_channel(struct rpc_channel *channel, unsigned int protocol)
90 {
91 	unsigned long eax, ebx, ecx, edx, si = 0, di = 0;
92 
93 	VMW_PORT(VMW_PORT_CMD_OPEN_CHANNEL,
94 		(protocol | GUESTMSG_FLAG_COOKIE), si, di,
95 		VMW_HYPERVISOR_PORT,
96 		VMW_HYPERVISOR_MAGIC,
97 		eax, ebx, ecx, edx, si, di);
98 
99 	if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0)
100 		return -EINVAL;
101 
102 	channel->channel_id  = HIGH_WORD(edx);
103 	channel->cookie_high = si;
104 	channel->cookie_low  = di;
105 
106 	return 0;
107 }
108 
109 
110 
111 /**
112  * vmw_close_channel
113  *
114  * @channel: RPC channel
115  *
116  * Returns: 0 on success
117  */
118 static int vmw_close_channel(struct rpc_channel *channel)
119 {
120 	unsigned long eax, ebx, ecx, edx, si, di;
121 
122 	/* Set up additional parameters */
123 	si  = channel->cookie_high;
124 	di  = channel->cookie_low;
125 
126 	VMW_PORT(VMW_PORT_CMD_CLOSE_CHANNEL,
127 		0, si, di,
128 		(VMW_HYPERVISOR_PORT | (channel->channel_id << 16)),
129 		VMW_HYPERVISOR_MAGIC,
130 		eax, ebx, ecx, edx, si, di);
131 
132 	if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0)
133 		return -EINVAL;
134 
135 	return 0;
136 }
137 
138 
139 
140 /**
141  * vmw_send_msg: Sends a message to the host
142  *
143  * @channel: RPC channel
144  * @logmsg: NULL terminated string
145  *
146  * Returns: 0 on success
147  */
148 static int vmw_send_msg(struct rpc_channel *channel, const char *msg)
149 {
150 	unsigned long eax, ebx, ecx, edx, si, di, bp;
151 	size_t msg_len = strlen(msg);
152 	int retries = 0;
153 
154 
155 	while (retries < RETRIES) {
156 		retries++;
157 
158 		/* Set up additional parameters */
159 		si  = channel->cookie_high;
160 		di  = channel->cookie_low;
161 
162 		VMW_PORT(VMW_PORT_CMD_SENDSIZE,
163 			msg_len, si, di,
164 			VMW_HYPERVISOR_PORT | (channel->channel_id << 16),
165 			VMW_HYPERVISOR_MAGIC,
166 			eax, ebx, ecx, edx, si, di);
167 
168 		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0 ||
169 		    (HIGH_WORD(ecx) & MESSAGE_STATUS_HB) == 0) {
170 			/* Expected success + high-bandwidth. Give up. */
171 			return -EINVAL;
172 		}
173 
174 		/* Send msg */
175 		si  = (uintptr_t) msg;
176 		di  = channel->cookie_low;
177 		bp  = channel->cookie_high;
178 
179 		VMW_PORT_HB_OUT(
180 			(MESSAGE_STATUS_SUCCESS << 16) | VMW_PORT_CMD_HB_MSG,
181 			msg_len, si, di,
182 			VMW_HYPERVISOR_HB_PORT | (channel->channel_id << 16),
183 			VMW_HYPERVISOR_MAGIC, bp,
184 			eax, ebx, ecx, edx, si, di);
185 
186 		if ((HIGH_WORD(ebx) & MESSAGE_STATUS_SUCCESS) != 0) {
187 			return 0;
188 		} else if ((HIGH_WORD(ebx) & MESSAGE_STATUS_CPT) != 0) {
189 			/* A checkpoint occurred. Retry. */
190 			continue;
191 		} else {
192 			break;
193 		}
194 	}
195 
196 	return -EINVAL;
197 }
198 STACK_FRAME_NON_STANDARD(vmw_send_msg);
199 
200 
201 /**
202  * vmw_recv_msg: Receives a message from the host
203  *
204  * Note:  It is the caller's responsibility to call kfree() on msg.
205  *
206  * @channel:  channel opened by vmw_open_channel
207  * @msg:  [OUT] message received from the host
208  * @msg_len: message length
209  */
210 static int vmw_recv_msg(struct rpc_channel *channel, void **msg,
211 			size_t *msg_len)
212 {
213 	unsigned long eax, ebx, ecx, edx, si, di, bp;
214 	char *reply;
215 	size_t reply_len;
216 	int retries = 0;
217 
218 
219 	*msg_len = 0;
220 	*msg = NULL;
221 
222 	while (retries < RETRIES) {
223 		retries++;
224 
225 		/* Set up additional parameters */
226 		si  = channel->cookie_high;
227 		di  = channel->cookie_low;
228 
229 		VMW_PORT(VMW_PORT_CMD_RECVSIZE,
230 			0, si, di,
231 			(VMW_HYPERVISOR_PORT | (channel->channel_id << 16)),
232 			VMW_HYPERVISOR_MAGIC,
233 			eax, ebx, ecx, edx, si, di);
234 
235 		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0 ||
236 		    (HIGH_WORD(ecx) & MESSAGE_STATUS_HB) == 0) {
237 			DRM_ERROR("Failed to get reply size\n");
238 			return -EINVAL;
239 		}
240 
241 		/* No reply available.  This is okay. */
242 		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_DORECV) == 0)
243 			return 0;
244 
245 		reply_len = ebx;
246 		reply     = kzalloc(reply_len + 1, GFP_KERNEL);
247 		if (reply == NULL) {
248 			DRM_ERROR("Cannot allocate memory for reply\n");
249 			return -ENOMEM;
250 		}
251 
252 
253 		/* Receive buffer */
254 		si  = channel->cookie_high;
255 		di  = (uintptr_t) reply;
256 		bp  = channel->cookie_low;
257 
258 		VMW_PORT_HB_IN(
259 			(MESSAGE_STATUS_SUCCESS << 16) | VMW_PORT_CMD_HB_MSG,
260 			reply_len, si, di,
261 			VMW_HYPERVISOR_HB_PORT | (channel->channel_id << 16),
262 			VMW_HYPERVISOR_MAGIC, bp,
263 			eax, ebx, ecx, edx, si, di);
264 
265 		if ((HIGH_WORD(ebx) & MESSAGE_STATUS_SUCCESS) == 0) {
266 			kfree(reply);
267 
268 			if ((HIGH_WORD(ebx) & MESSAGE_STATUS_CPT) != 0) {
269 				/* A checkpoint occurred. Retry. */
270 				continue;
271 			}
272 
273 			return -EINVAL;
274 		}
275 
276 		reply[reply_len] = '\0';
277 
278 
279 		/* Ack buffer */
280 		si  = channel->cookie_high;
281 		di  = channel->cookie_low;
282 
283 		VMW_PORT(VMW_PORT_CMD_RECVSTATUS,
284 			MESSAGE_STATUS_SUCCESS, si, di,
285 			(VMW_HYPERVISOR_PORT | (channel->channel_id << 16)),
286 			VMW_HYPERVISOR_MAGIC,
287 			eax, ebx, ecx, edx, si, di);
288 
289 		if ((HIGH_WORD(ecx) & MESSAGE_STATUS_SUCCESS) == 0) {
290 			kfree(reply);
291 
292 			if ((HIGH_WORD(ecx) & MESSAGE_STATUS_CPT) != 0) {
293 				/* A checkpoint occurred. Retry. */
294 				continue;
295 			}
296 
297 			return -EINVAL;
298 		}
299 
300 		break;
301 	}
302 
303 	if (retries == RETRIES)
304 		return -EINVAL;
305 
306 	*msg_len = reply_len;
307 	*msg     = reply;
308 
309 	return 0;
310 }
311 STACK_FRAME_NON_STANDARD(vmw_recv_msg);
312 
313 
314 /**
315  * vmw_host_get_guestinfo: Gets a GuestInfo parameter
316  *
317  * Gets the value of a  GuestInfo.* parameter.  The value returned will be in
318  * a string, and it is up to the caller to post-process.
319  *
320  * @guest_info_param:  Parameter to get, e.g. GuestInfo.svga.gl3
321  * @buffer: if NULL, *reply_len will contain reply size.
322  * @length: size of the reply_buf.  Set to size of reply upon return
323  *
324  * Returns: 0 on success
325  */
326 int vmw_host_get_guestinfo(const char *guest_info_param,
327 			   char *buffer, size_t *length)
328 {
329 	struct rpc_channel channel;
330 	char *msg, *reply = NULL;
331 	size_t msg_len, reply_len = 0;
332 	int ret = 0;
333 
334 
335 	if (!vmw_msg_enabled)
336 		return -ENODEV;
337 
338 	if (!guest_info_param || !length)
339 		return -EINVAL;
340 
341 	msg_len = strlen(guest_info_param) + strlen("info-get ") + 1;
342 	msg = kzalloc(msg_len, GFP_KERNEL);
343 	if (msg == NULL) {
344 		DRM_ERROR("Cannot allocate memory to get %s", guest_info_param);
345 		return -ENOMEM;
346 	}
347 
348 	sprintf(msg, "info-get %s", guest_info_param);
349 
350 	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM) ||
351 	    vmw_send_msg(&channel, msg) ||
352 	    vmw_recv_msg(&channel, (void *) &reply, &reply_len) ||
353 	    vmw_close_channel(&channel)) {
354 		DRM_ERROR("Failed to get %s", guest_info_param);
355 
356 		ret = -EINVAL;
357 	}
358 
359 	if (buffer && reply && reply_len > 0) {
360 		/* Remove reply code, which are the first 2 characters of
361 		 * the reply
362 		 */
363 		reply_len = max(reply_len - 2, (size_t) 0);
364 		reply_len = min(reply_len, *length);
365 
366 		if (reply_len > 0)
367 			memcpy(buffer, reply + 2, reply_len);
368 	}
369 
370 	*length = reply_len;
371 
372 	kfree(reply);
373 	kfree(msg);
374 
375 	return ret;
376 }
377 
378 
379 
380 /**
381  * vmw_host_log: Sends a log message to the host
382  *
383  * @log: NULL terminated string
384  *
385  * Returns: 0 on success
386  */
387 int vmw_host_log(const char *log)
388 {
389 	struct rpc_channel channel;
390 	char *msg;
391 	int msg_len;
392 	int ret = 0;
393 
394 
395 	if (!vmw_msg_enabled)
396 		return -ENODEV;
397 
398 	if (!log)
399 		return ret;
400 
401 	msg_len = strlen(log) + strlen("log ") + 1;
402 	msg = kzalloc(msg_len, GFP_KERNEL);
403 	if (msg == NULL) {
404 		DRM_ERROR("Cannot allocate memory for log message\n");
405 		return -ENOMEM;
406 	}
407 
408 	sprintf(msg, "log %s", log);
409 
410 	if (vmw_open_channel(&channel, RPCI_PROTOCOL_NUM) ||
411 	    vmw_send_msg(&channel, msg) ||
412 	    vmw_close_channel(&channel)) {
413 		DRM_ERROR("Failed to send log\n");
414 
415 		ret = -EINVAL;
416 	}
417 
418 	kfree(msg);
419 
420 	return ret;
421 }
422