xref: /linux/drivers/platform/x86/amd/hsmp/hsmp.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * AMD HSMP Platform Driver
4  * Copyright (c) 2022, AMD.
5  * All Rights Reserved.
6  *
7  * This file provides a device implementation for HSMP interface
8  */
9 
10 #include <asm/amd_hsmp.h>
11 #include <asm/amd_nb.h>
12 
13 #include <linux/acpi.h>
14 #include <linux/delay.h>
15 #include <linux/device.h>
16 #include <linux/semaphore.h>
17 #include <linux/sysfs.h>
18 
19 #include "hsmp.h"
20 
21 /* HSMP Status / Error codes */
22 #define HSMP_STATUS_NOT_READY	0x00
23 #define HSMP_STATUS_OK		0x01
24 #define HSMP_ERR_INVALID_MSG	0xFE
25 #define HSMP_ERR_INVALID_INPUT	0xFF
26 #define HSMP_ERR_PREREQ_NOT_SATISFIED	0xFD
27 #define HSMP_ERR_SMU_BUSY		0xFC
28 
29 /* Timeout in millsec */
30 #define HSMP_MSG_TIMEOUT	100
31 #define HSMP_SHORT_SLEEP	1
32 
33 #define HSMP_WR			true
34 #define HSMP_RD			false
35 
36 #define DRIVER_VERSION		"2.3"
37 
38 static struct hsmp_plat_device hsmp_pdev;
39 
40 /*
41  * Send a message to the HSMP port via PCI-e config space registers
42  * or by writing to MMIO space.
43  *
44  * The caller is expected to zero out any unused arguments.
45  * If a response is expected, the number of response words should be greater than 0.
46  *
47  * Returns 0 for success and populates the requested number of arguments.
48  * Returns a negative error code for failure.
49  */
50 static int __hsmp_send_message(struct hsmp_socket *sock, struct hsmp_message *msg)
51 {
52 	struct hsmp_mbaddr_info *mbinfo;
53 	unsigned long timeout, short_sleep;
54 	u32 mbox_status;
55 	u32 index;
56 	int ret;
57 
58 	mbinfo = &sock->mbinfo;
59 
60 	/* Clear the status register */
61 	mbox_status = HSMP_STATUS_NOT_READY;
62 	ret = sock->amd_hsmp_rdwr(sock, mbinfo->msg_resp_off, &mbox_status, HSMP_WR);
63 	if (ret) {
64 		dev_err(sock->dev, "Error %d clearing mailbox status register\n", ret);
65 		return ret;
66 	}
67 
68 	index = 0;
69 	/* Write any message arguments */
70 	while (index < msg->num_args) {
71 		ret = sock->amd_hsmp_rdwr(sock, mbinfo->msg_arg_off + (index << 2),
72 					  &msg->args[index], HSMP_WR);
73 		if (ret) {
74 			dev_err(sock->dev, "Error %d writing message argument %d\n", ret, index);
75 			return ret;
76 		}
77 		index++;
78 	}
79 
80 	/* Write the message ID which starts the operation */
81 	ret = sock->amd_hsmp_rdwr(sock, mbinfo->msg_id_off, &msg->msg_id, HSMP_WR);
82 	if (ret) {
83 		dev_err(sock->dev, "Error %d writing message ID %u\n", ret, msg->msg_id);
84 		return ret;
85 	}
86 
87 	/*
88 	 * Depending on when the trigger write completes relative to the SMU
89 	 * firmware 1 ms cycle, the operation may take from tens of us to 1 ms
90 	 * to complete. Some operations may take more. Therefore we will try
91 	 * a few short duration sleeps and switch to long sleeps if we don't
92 	 * succeed quickly.
93 	 */
94 	short_sleep = jiffies + msecs_to_jiffies(HSMP_SHORT_SLEEP);
95 	timeout	= jiffies + msecs_to_jiffies(HSMP_MSG_TIMEOUT);
96 
97 	while (time_before(jiffies, timeout)) {
98 		ret = sock->amd_hsmp_rdwr(sock, mbinfo->msg_resp_off, &mbox_status, HSMP_RD);
99 		if (ret) {
100 			dev_err(sock->dev, "Error %d reading mailbox status\n", ret);
101 			return ret;
102 		}
103 
104 		if (mbox_status != HSMP_STATUS_NOT_READY)
105 			break;
106 		if (time_before(jiffies, short_sleep))
107 			usleep_range(50, 100);
108 		else
109 			usleep_range(1000, 2000);
110 	}
111 
112 	if (unlikely(mbox_status == HSMP_STATUS_NOT_READY)) {
113 		dev_err(sock->dev, "Message ID 0x%X failure : SMU tmeout (status = 0x%X)\n",
114 			msg->msg_id, mbox_status);
115 		return -ETIMEDOUT;
116 	} else if (unlikely(mbox_status == HSMP_ERR_INVALID_MSG)) {
117 		dev_err(sock->dev, "Message ID 0x%X failure : Invalid message (status = 0x%X)\n",
118 			msg->msg_id, mbox_status);
119 		return -ENOMSG;
120 	} else if (unlikely(mbox_status == HSMP_ERR_INVALID_INPUT)) {
121 		dev_err(sock->dev, "Message ID 0x%X failure : Invalid arguments (status = 0x%X)\n",
122 			msg->msg_id, mbox_status);
123 		return -EINVAL;
124 	} else if (unlikely(mbox_status == HSMP_ERR_PREREQ_NOT_SATISFIED)) {
125 		dev_err(sock->dev, "Message ID 0x%X failure : Prerequisite not satisfied (status = 0x%X)\n",
126 			msg->msg_id, mbox_status);
127 		return -EREMOTEIO;
128 	} else if (unlikely(mbox_status == HSMP_ERR_SMU_BUSY)) {
129 		dev_err(sock->dev, "Message ID 0x%X failure : SMU BUSY (status = 0x%X)\n",
130 			msg->msg_id, mbox_status);
131 		return -EBUSY;
132 	} else if (unlikely(mbox_status != HSMP_STATUS_OK)) {
133 		dev_err(sock->dev, "Message ID 0x%X unknown failure (status = 0x%X)\n",
134 			msg->msg_id, mbox_status);
135 		return -EIO;
136 	}
137 
138 	/*
139 	 * SMU has responded OK. Read response data.
140 	 * SMU reads the input arguments from eight 32 bit registers starting
141 	 * from SMN_HSMP_MSG_DATA and writes the response data to the same
142 	 * SMN_HSMP_MSG_DATA address.
143 	 * We copy the response data if any, back to the args[].
144 	 */
145 	index = 0;
146 	while (index < msg->response_sz) {
147 		ret = sock->amd_hsmp_rdwr(sock, mbinfo->msg_arg_off + (index << 2),
148 					  &msg->args[index], HSMP_RD);
149 		if (ret) {
150 			dev_err(sock->dev, "Error %d reading response %u for message ID:%u\n",
151 				ret, index, msg->msg_id);
152 			break;
153 		}
154 		index++;
155 	}
156 
157 	return ret;
158 }
159 
160 static int validate_message(struct hsmp_message *msg)
161 {
162 	/* msg_id against valid range of message IDs */
163 	if (msg->msg_id < HSMP_TEST || msg->msg_id >= HSMP_MSG_ID_MAX)
164 		return -ENOMSG;
165 
166 	/* msg_id is a reserved message ID */
167 	if (hsmp_msg_desc_table[msg->msg_id].type == HSMP_RSVD)
168 		return -ENOMSG;
169 
170 	/* num_args and response_sz against the HSMP spec */
171 	if (msg->num_args != hsmp_msg_desc_table[msg->msg_id].num_args ||
172 	    msg->response_sz != hsmp_msg_desc_table[msg->msg_id].response_sz)
173 		return -EINVAL;
174 
175 	return 0;
176 }
177 
178 int hsmp_send_message(struct hsmp_message *msg)
179 {
180 	struct hsmp_socket *sock;
181 	int ret;
182 
183 	if (!msg)
184 		return -EINVAL;
185 	ret = validate_message(msg);
186 	if (ret)
187 		return ret;
188 
189 	if (!hsmp_pdev.sock || msg->sock_ind >= hsmp_pdev.num_sockets)
190 		return -ENODEV;
191 	sock = &hsmp_pdev.sock[msg->sock_ind];
192 
193 	/*
194 	 * The time taken by smu operation to complete is between
195 	 * 10us to 1ms. Sometime it may take more time.
196 	 * In SMP system timeout of 100 millisecs should
197 	 * be enough for the previous thread to finish the operation
198 	 */
199 	ret = down_timeout(&sock->hsmp_sem, msecs_to_jiffies(HSMP_MSG_TIMEOUT));
200 	if (ret < 0)
201 		return ret;
202 
203 	ret = __hsmp_send_message(sock, msg);
204 
205 	up(&sock->hsmp_sem);
206 
207 	return ret;
208 }
209 EXPORT_SYMBOL_NS_GPL(hsmp_send_message, AMD_HSMP);
210 
211 int hsmp_test(u16 sock_ind, u32 value)
212 {
213 	struct hsmp_message msg = { 0 };
214 	int ret;
215 
216 	/*
217 	 * Test the hsmp port by performing TEST command. The test message
218 	 * takes one argument and returns the value of that argument + 1.
219 	 */
220 	msg.msg_id	= HSMP_TEST;
221 	msg.num_args	= 1;
222 	msg.response_sz	= 1;
223 	msg.args[0]	= value;
224 	msg.sock_ind	= sock_ind;
225 
226 	ret = hsmp_send_message(&msg);
227 	if (ret)
228 		return ret;
229 
230 	/* Check the response value */
231 	if (msg.args[0] != (value + 1)) {
232 		dev_err(hsmp_pdev.sock[sock_ind].dev,
233 			"Socket %d test message failed, Expected 0x%08X, received 0x%08X\n",
234 			sock_ind, (value + 1), msg.args[0]);
235 		return -EBADE;
236 	}
237 
238 	return ret;
239 }
240 EXPORT_SYMBOL_NS_GPL(hsmp_test, AMD_HSMP);
241 
242 long hsmp_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
243 {
244 	int __user *arguser = (int  __user *)arg;
245 	struct hsmp_message msg = { 0 };
246 	int ret;
247 
248 	if (copy_struct_from_user(&msg, sizeof(msg), arguser, sizeof(struct hsmp_message)))
249 		return -EFAULT;
250 
251 	/*
252 	 * Check msg_id is within the range of supported msg ids
253 	 * i.e within the array bounds of hsmp_msg_desc_table
254 	 */
255 	if (msg.msg_id < HSMP_TEST || msg.msg_id >= HSMP_MSG_ID_MAX)
256 		return -ENOMSG;
257 
258 	switch (fp->f_mode & (FMODE_WRITE | FMODE_READ)) {
259 	case FMODE_WRITE:
260 		/*
261 		 * Device is opened in O_WRONLY mode
262 		 * Execute only set/configure commands
263 		 */
264 		if (hsmp_msg_desc_table[msg.msg_id].type != HSMP_SET)
265 			return -EPERM;
266 		break;
267 	case FMODE_READ:
268 		/*
269 		 * Device is opened in O_RDONLY mode
270 		 * Execute only get/monitor commands
271 		 */
272 		if (hsmp_msg_desc_table[msg.msg_id].type != HSMP_GET)
273 			return -EPERM;
274 		break;
275 	case FMODE_READ | FMODE_WRITE:
276 		/*
277 		 * Device is opened in O_RDWR mode
278 		 * Execute both get/monitor and set/configure commands
279 		 */
280 		break;
281 	default:
282 		return -EPERM;
283 	}
284 
285 	ret = hsmp_send_message(&msg);
286 	if (ret)
287 		return ret;
288 
289 	if (hsmp_msg_desc_table[msg.msg_id].response_sz > 0) {
290 		/* Copy results back to user for get/monitor commands */
291 		if (copy_to_user(arguser, &msg, sizeof(struct hsmp_message)))
292 			return -EFAULT;
293 	}
294 
295 	return 0;
296 }
297 
298 ssize_t hsmp_metric_tbl_read(struct hsmp_socket *sock, char *buf, size_t size)
299 {
300 	struct hsmp_message msg = { 0 };
301 	int ret;
302 
303 	if (!sock || !buf)
304 		return -EINVAL;
305 
306 	/* Do not support lseek(), also don't allow more than the size of metric table */
307 	if (size != sizeof(struct hsmp_metric_table)) {
308 		dev_err(sock->dev, "Wrong buffer size\n");
309 		return -EINVAL;
310 	}
311 
312 	msg.msg_id	= HSMP_GET_METRIC_TABLE;
313 	msg.sock_ind	= sock->sock_ind;
314 
315 	ret = hsmp_send_message(&msg);
316 	if (ret)
317 		return ret;
318 	memcpy_fromio(buf, sock->metric_tbl_addr, size);
319 
320 	return size;
321 }
322 EXPORT_SYMBOL_NS_GPL(hsmp_metric_tbl_read, AMD_HSMP);
323 
324 int hsmp_get_tbl_dram_base(u16 sock_ind)
325 {
326 	struct hsmp_socket *sock = &hsmp_pdev.sock[sock_ind];
327 	struct hsmp_message msg = { 0 };
328 	phys_addr_t dram_addr;
329 	int ret;
330 
331 	msg.sock_ind	= sock_ind;
332 	msg.response_sz	= hsmp_msg_desc_table[HSMP_GET_METRIC_TABLE_DRAM_ADDR].response_sz;
333 	msg.msg_id	= HSMP_GET_METRIC_TABLE_DRAM_ADDR;
334 
335 	ret = hsmp_send_message(&msg);
336 	if (ret)
337 		return ret;
338 
339 	/*
340 	 * calculate the metric table DRAM address from lower and upper 32 bits
341 	 * sent from SMU and ioremap it to virtual address.
342 	 */
343 	dram_addr = msg.args[0] | ((u64)(msg.args[1]) << 32);
344 	if (!dram_addr) {
345 		dev_err(sock->dev, "Invalid DRAM address for metric table\n");
346 		return -ENOMEM;
347 	}
348 	sock->metric_tbl_addr = devm_ioremap(sock->dev, dram_addr,
349 					     sizeof(struct hsmp_metric_table));
350 	if (!sock->metric_tbl_addr) {
351 		dev_err(sock->dev, "Failed to ioremap metric table addr\n");
352 		return -ENOMEM;
353 	}
354 	return 0;
355 }
356 EXPORT_SYMBOL_NS_GPL(hsmp_get_tbl_dram_base, AMD_HSMP);
357 
358 int hsmp_cache_proto_ver(u16 sock_ind)
359 {
360 	struct hsmp_message msg = { 0 };
361 	int ret;
362 
363 	msg.msg_id	= HSMP_GET_PROTO_VER;
364 	msg.sock_ind	= sock_ind;
365 	msg.response_sz = hsmp_msg_desc_table[HSMP_GET_PROTO_VER].response_sz;
366 
367 	ret = hsmp_send_message(&msg);
368 	if (!ret)
369 		hsmp_pdev.proto_ver = msg.args[0];
370 
371 	return ret;
372 }
373 EXPORT_SYMBOL_NS_GPL(hsmp_cache_proto_ver, AMD_HSMP);
374 
375 static const struct file_operations hsmp_fops = {
376 	.owner		= THIS_MODULE,
377 	.unlocked_ioctl	= hsmp_ioctl,
378 	.compat_ioctl	= hsmp_ioctl,
379 };
380 
381 int hsmp_misc_register(struct device *dev)
382 {
383 	hsmp_pdev.mdev.name	= HSMP_CDEV_NAME;
384 	hsmp_pdev.mdev.minor	= MISC_DYNAMIC_MINOR;
385 	hsmp_pdev.mdev.fops	= &hsmp_fops;
386 	hsmp_pdev.mdev.parent	= dev;
387 	hsmp_pdev.mdev.nodename	= HSMP_DEVNODE_NAME;
388 	hsmp_pdev.mdev.mode	= 0644;
389 
390 	return misc_register(&hsmp_pdev.mdev);
391 }
392 EXPORT_SYMBOL_NS_GPL(hsmp_misc_register, AMD_HSMP);
393 
394 void hsmp_misc_deregister(void)
395 {
396 	misc_deregister(&hsmp_pdev.mdev);
397 }
398 EXPORT_SYMBOL_NS_GPL(hsmp_misc_deregister, AMD_HSMP);
399 
400 struct hsmp_plat_device *get_hsmp_pdev(void)
401 {
402 	return &hsmp_pdev;
403 }
404 EXPORT_SYMBOL_NS_GPL(get_hsmp_pdev, AMD_HSMP);
405 
406 MODULE_DESCRIPTION("AMD HSMP Common driver");
407 MODULE_VERSION(DRIVER_VERSION);
408 MODULE_LICENSE("GPL");
409