1 /*
2  * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 
8 #include <arch_helpers.h>
9 
10 #include <lib/bakery_lock.h>
11 #include <lib/mmio.h>
12 
13 #include <ipi.h>
14 #include <plat_ipi.h>
15 #include <plat_private.h>
16 #include <plat/common/platform.h>
17 
18 #include "pm_ipi.h"
19 
20 
21 #define ERROR_CODE_MASK		0xFFFFU
22 
23 DEFINE_BAKERY_LOCK(pm_secure_lock);
24 
25 /**
26  * pm_ipi_init() - Initialize IPI peripheral for communication with
27  *		   remote processor
28  *
29  * @proc	Pointer to the processor who is initiating request
30  * @return	On success, the initialization function must return 0.
31  *		Any other return value will cause the framework to ignore
32  *		the service
33  *
34  * Called from pm_setup initialization function
35  */
pm_ipi_init(const struct pm_proc * proc)36 int pm_ipi_init(const struct pm_proc *proc)
37 {
38 	bakery_lock_init(&pm_secure_lock);
39 	ipi_mb_open(proc->ipi->local_ipi_id, proc->ipi->remote_ipi_id);
40 
41 	return 0;
42 }
43 
44 /**
45  * pm_ipi_send_common() - Sends IPI request to the remote processor
46  * @proc	Pointer to the processor who is initiating request
47  * @payload	API id and call arguments to be written in IPI buffer
48  *
49  * Send an IPI request to the power controller. Caller needs to hold
50  * the 'pm_secure_lock' lock.
51  *
52  * @return	Returns status, either success or error+reason
53  */
pm_ipi_send_common(const struct pm_proc * proc,uint32_t payload[PAYLOAD_ARG_CNT],uint32_t is_blocking)54 static enum pm_ret_status pm_ipi_send_common(const struct pm_proc *proc,
55 					     uint32_t payload[PAYLOAD_ARG_CNT],
56 					     uint32_t is_blocking)
57 {
58 	int status;
59 	unsigned int offset = 0;
60 	uintptr_t buffer_base = proc->ipi->buffer_base +
61 					IPI_BUFFER_TARGET_REMOTE_OFFSET +
62 					IPI_BUFFER_REQ_OFFSET;
63 #if IPI_CRC_CHECK
64 	payload[PAYLOAD_CRC_POS] = calculate_crc(payload, IPI_W0_TO_W6_SIZE);
65 #endif
66 
67 	/* Write payload into IPI buffer */
68 	for (size_t i = 0; i < PAYLOAD_ARG_CNT; i++) {
69 		mmio_write_32(buffer_base + offset, payload[i]);
70 		offset += PAYLOAD_ARG_SIZE;
71 	}
72 
73 	/* Generate IPI to remote processor */
74 	status = ipi_mb_notify(proc->ipi->local_ipi_id, proc->ipi->remote_ipi_id,
75 		      is_blocking);
76 	if (status == 0) {
77 		return PM_RET_SUCCESS;
78 	}
79 
80 	return PM_RET_ERROR_TIMEOUT;
81 }
82 
83 /**
84  * pm_ipi_send_non_blocking() - Sends IPI request to the remote processor
85  *			        without blocking notification
86  * @proc	Pointer to the processor who is initiating request
87  * @payload	API id and call arguments to be written in IPI buffer
88  *
89  * Send an IPI request to the power controller.
90  *
91  * @return	Returns status, either success or error+reason
92  */
pm_ipi_send_non_blocking(const struct pm_proc * proc,uint32_t payload[PAYLOAD_ARG_CNT])93 enum pm_ret_status pm_ipi_send_non_blocking(const struct pm_proc *proc,
94 					    uint32_t payload[PAYLOAD_ARG_CNT])
95 {
96 	enum pm_ret_status ret;
97 
98 	bakery_lock_get(&pm_secure_lock);
99 
100 	ret = pm_ipi_send_common(proc, payload, IPI_NON_BLOCKING);
101 
102 	bakery_lock_release(&pm_secure_lock);
103 
104 	return ret;
105 }
106 
107 /**
108  * pm_ipi_send() - Sends IPI request to the remote processor
109  * @proc	Pointer to the processor who is initiating request
110  * @payload	API id and call arguments to be written in IPI buffer
111  *
112  * Send an IPI request to the power controller.
113  *
114  * @return	Returns status, either success or error+reason
115  */
pm_ipi_send(const struct pm_proc * proc,uint32_t payload[PAYLOAD_ARG_CNT])116 enum pm_ret_status pm_ipi_send(const struct pm_proc *proc,
117 			       uint32_t payload[PAYLOAD_ARG_CNT])
118 {
119 	enum pm_ret_status ret;
120 
121 	bakery_lock_get(&pm_secure_lock);
122 
123 	ret = pm_ipi_send_common(proc, payload, IPI_BLOCKING);
124 
125 	bakery_lock_release(&pm_secure_lock);
126 
127 	return ret;
128 }
129 
130 
131 /**
132  * pm_ipi_buff_read() - Reads IPI response after remote processor has handled
133  *			interrupt
134  * @proc	Pointer to the processor who is waiting and reading response
135  * @value	Used to return value from IPI buffer element (optional)
136  * @count	Number of values to return in @value
137  *
138  * @return	Returns status, either success or error+reason
139  */
pm_ipi_buff_read(const struct pm_proc * proc,unsigned int * value,size_t count)140 static enum pm_ret_status pm_ipi_buff_read(const struct pm_proc *proc,
141 					   unsigned int *value, size_t count)
142 {
143 	size_t i;
144 #if IPI_CRC_CHECK
145 	size_t j;
146 	unsigned int response_payload[PAYLOAD_ARG_CNT];
147 #endif
148 	uintptr_t buffer_base = proc->ipi->buffer_base +
149 				IPI_BUFFER_TARGET_REMOTE_OFFSET +
150 				IPI_BUFFER_RESP_OFFSET;
151 
152 	/*
153 	 * Read response from IPI buffer
154 	 * buf-0: success or error+reason
155 	 * buf-1: value
156 	 * buf-2: unused
157 	 * buf-3: unused
158 	 */
159 	for (i = 1; i <= count; i++) {
160 		*value = mmio_read_32(buffer_base + (i * PAYLOAD_ARG_SIZE));
161 		value++;
162 	}
163 #if IPI_CRC_CHECK
164 	for (j = 0; j < PAYLOAD_ARG_CNT; j++)
165 		response_payload[j] = mmio_read_32(buffer_base +
166 						(j * PAYLOAD_ARG_SIZE));
167 
168 	if (response_payload[PAYLOAD_CRC_POS] !=
169 			calculate_crc(response_payload, IPI_W0_TO_W6_SIZE))
170 		NOTICE("ERROR in CRC response payload value:0x%x\n",
171 					response_payload[PAYLOAD_CRC_POS]);
172 #endif
173 
174 	return mmio_read_32(buffer_base);
175 }
176 
177 /**
178  * pm_ipi_buff_read_callb() - Reads IPI response after remote processor has
179  *			      handled interrupt
180  * @value	Used to return value from IPI buffer element (optional)
181  * @count	Number of values to return in @value
182  *
183  * @return	Returns status, either success or error+reason
184  */
pm_ipi_buff_read_callb(unsigned int * value,size_t count)185 void pm_ipi_buff_read_callb(unsigned int *value, size_t count)
186 {
187 	size_t i;
188 #if IPI_CRC_CHECK
189 	size_t j;
190 	unsigned int response_payload[PAYLOAD_ARG_CNT];
191 #endif
192 	uintptr_t buffer_base = IPI_BUFFER_REMOTE_BASE +
193 				IPI_BUFFER_TARGET_LOCAL_OFFSET +
194 				IPI_BUFFER_REQ_OFFSET;
195 
196 	if (count > IPI_BUFFER_MAX_WORDS)
197 		count = IPI_BUFFER_MAX_WORDS;
198 
199 	for (i = 0; i <= count; i++) {
200 		*value = mmio_read_32(buffer_base + (i * PAYLOAD_ARG_SIZE));
201 		value++;
202 	}
203 #if IPI_CRC_CHECK
204 	for (j = 0; j < PAYLOAD_ARG_CNT; j++)
205 		response_payload[j] = mmio_read_32(buffer_base +
206 						(j * PAYLOAD_ARG_SIZE));
207 
208 	if (response_payload[PAYLOAD_CRC_POS] !=
209 			calculate_crc(response_payload, IPI_W0_TO_W6_SIZE))
210 		NOTICE("ERROR in CRC response payload value:0x%x\n",
211 					response_payload[PAYLOAD_CRC_POS]);
212 #endif
213 }
214 
215 /**
216  * pm_ipi_send_sync() - Sends IPI request to the remote processor
217  * @proc	Pointer to the processor who is initiating request
218  * @payload	API id and call arguments to be written in IPI buffer
219  * @value	Used to return value from IPI buffer element (optional)
220  * @count	Number of values to return in @value
221  *
222  * Send an IPI request to the power controller and wait for it to be handled.
223  *
224  * @return	Returns status, either success or error+reason and, optionally,
225  *		@value
226  */
pm_ipi_send_sync(const struct pm_proc * proc,uint32_t payload[PAYLOAD_ARG_CNT],unsigned int * value,size_t count)227 enum pm_ret_status pm_ipi_send_sync(const struct pm_proc *proc,
228 				    uint32_t payload[PAYLOAD_ARG_CNT],
229 				    unsigned int *value, size_t count)
230 {
231 	enum pm_ret_status ret;
232 
233 	bakery_lock_get(&pm_secure_lock);
234 
235 	ret = pm_ipi_send_common(proc, payload, IPI_BLOCKING);
236 	if (ret != PM_RET_SUCCESS)
237 		goto unlock;
238 
239 	ret = ERROR_CODE_MASK & (pm_ipi_buff_read(proc, value, count));
240 
241 unlock:
242 	bakery_lock_release(&pm_secure_lock);
243 
244 	return ret;
245 }
246 
pm_ipi_irq_enable(const struct pm_proc * proc)247 void pm_ipi_irq_enable(const struct pm_proc *proc)
248 {
249 	ipi_mb_enable_irq(proc->ipi->local_ipi_id, proc->ipi->remote_ipi_id);
250 }
251 
pm_ipi_irq_clear(const struct pm_proc * proc)252 void pm_ipi_irq_clear(const struct pm_proc *proc)
253 {
254 	ipi_mb_ack(proc->ipi->local_ipi_id, proc->ipi->remote_ipi_id);
255 }
256 
pm_ipi_irq_status(const struct pm_proc * proc)257 uint32_t pm_ipi_irq_status(const struct pm_proc *proc)
258 {
259 	int ret;
260 
261 	ret = ipi_mb_enquire_status(proc->ipi->local_ipi_id,
262 				    proc->ipi->remote_ipi_id);
263 	if (ret & IPI_MB_STATUS_RECV_PENDING)
264 		return 1;
265 	else
266 		return 0;
267 }
268 
269 #if IPI_CRC_CHECK
calculate_crc(uint32_t * payload,uint32_t bufsize)270 uint32_t calculate_crc(uint32_t *payload, uint32_t bufsize)
271 {
272 	uint32_t crcinit = CRC_INIT_VALUE;
273 	uint32_t order   = CRC_ORDER;
274 	uint32_t polynom = CRC_POLYNOM;
275 	uint32_t i, j, c, bit, datain, crcmask, crchighbit;
276 	uint32_t crc = crcinit;
277 
278 	crcmask = ((uint32_t)((1U << (order - 1U)) - 1U) << 1U) | 1U;
279 	crchighbit = (uint32_t)(1U << (order - 1U));
280 
281 	for (i = 0U; i < bufsize; i++) {
282 		datain = mmio_read_8((unsigned long)payload + i);
283 		c = datain;
284 		j = 0x80U;
285 		while (j != 0U) {
286 			bit = crc & crchighbit;
287 			crc <<= 1U;
288 			if (0U != (c & j))
289 				bit ^= crchighbit;
290 			if (bit != 0U)
291 				crc ^= polynom;
292 			j >>= 1U;
293 		}
294 		crc &= crcmask;
295 	}
296 	return crc;
297 }
298 #endif
299