1 /*
2  * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
3  * Copyright (c) 2019-2022, Xilinx, Inc. All rights reserved.
4  * Copyright (c) 2022, Advanced Micro Devices, Inc. All rights reserved.
5  *
6  * SPDX-License-Identifier: BSD-3-Clause
7  */
8 
9 
10 #include <arch_helpers.h>
11 #include <lib/bakery_lock.h>
12 #include <lib/mmio.h>
13 #include <ipi.h>
14 #include <plat_ipi.h>
15 #include <plat_private.h>
16 #include <plat/common/platform.h>
17 
18 #include "pm_defs.h"
19 #include "pm_ipi.h"
20 
21 #define ERROR_CODE_MASK		(0xFFFFU)
22 #define PM_OFFSET		(0U)
23 
24 DEFINE_BAKERY_LOCK(pm_secure_lock);
25 
26 /**
27  * pm_ipi_init() - Initialize IPI peripheral for communication with
28  *		   remote processor
29  *
30  * @proc	Pointer to the processor who is initiating request
31  * @return	On success, the initialization function must return 0.
32  *		Any other return value will cause the framework to ignore
33  *		the service
34  *
35  * Called from pm_setup initialization function
36  */
pm_ipi_init(const struct pm_proc * proc)37 void pm_ipi_init(const struct pm_proc *proc)
38 {
39 	bakery_lock_init(&pm_secure_lock);
40 	ipi_mb_open(proc->ipi->local_ipi_id, proc->ipi->remote_ipi_id);
41 }
42 
43 /**
44  * pm_ipi_send_common() - Sends IPI request to the remote processor
45  * @proc	Pointer to the processor who is initiating request
46  * @payload	API id and call arguments to be written in IPI buffer
47  *
48  * Send an IPI request to the power controller. Caller needs to hold
49  * the 'pm_secure_lock' lock.
50  *
51  * @return	Returns status, either success or error+reason
52  */
pm_ipi_send_common(const struct pm_proc * proc,uint32_t payload[PAYLOAD_ARG_CNT],uint32_t is_blocking)53 static enum pm_ret_status pm_ipi_send_common(const struct pm_proc *proc,
54 					     uint32_t payload[PAYLOAD_ARG_CNT],
55 					     uint32_t is_blocking)
56 {
57 	uint32_t offset = PM_OFFSET;
58 	uintptr_t buffer_base = proc->ipi->buffer_base +
59 					IPI_BUFFER_TARGET_REMOTE_OFFSET +
60 					IPI_BUFFER_REQ_OFFSET;
61 #if IPI_CRC_CHECK
62 	payload[PAYLOAD_CRC_POS] = calculate_crc(payload, IPI_W0_TO_W6_SIZE);
63 #endif
64 
65 	/* Write payload into IPI buffer */
66 	for (size_t i = 0; i < PAYLOAD_ARG_CNT; i++) {
67 		mmio_write_32(buffer_base + offset, payload[i]);
68 		offset += PAYLOAD_ARG_SIZE;
69 	}
70 
71 	/* Generate IPI to remote processor */
72 	ipi_mb_notify(proc->ipi->local_ipi_id, proc->ipi->remote_ipi_id,
73 		      is_blocking);
74 
75 	return PM_RET_SUCCESS;
76 }
77 
78 /**
79  * pm_ipi_send_non_blocking() - Sends IPI request to the remote processor
80  *			        without blocking notification
81  * @proc	Pointer to the processor who is initiating request
82  * @payload	API id and call arguments to be written in IPI buffer
83  *
84  * Send an IPI request to the power controller.
85  *
86  * @return	Returns status, either success or error+reason
87  */
pm_ipi_send_non_blocking(const struct pm_proc * proc,uint32_t payload[PAYLOAD_ARG_CNT])88 enum pm_ret_status pm_ipi_send_non_blocking(const struct pm_proc *proc,
89 					    uint32_t payload[PAYLOAD_ARG_CNT])
90 {
91 	enum pm_ret_status ret;
92 
93 	bakery_lock_get(&pm_secure_lock);
94 
95 	ret = pm_ipi_send_common(proc, payload, IPI_NON_BLOCKING);
96 
97 	bakery_lock_release(&pm_secure_lock);
98 
99 	return ret;
100 }
101 
102 /**
103  * pm_ipi_send() - Sends IPI request to the remote processor
104  * @proc	Pointer to the processor who is initiating request
105  * @payload	API id and call arguments to be written in IPI buffer
106  *
107  * Send an IPI request to the power controller.
108  *
109  * @return	Returns status, either success or error+reason
110  */
pm_ipi_send(const struct pm_proc * proc,uint32_t payload[PAYLOAD_ARG_CNT])111 enum pm_ret_status pm_ipi_send(const struct pm_proc *proc,
112 			       uint32_t payload[PAYLOAD_ARG_CNT])
113 {
114 	enum pm_ret_status ret;
115 
116 	bakery_lock_get(&pm_secure_lock);
117 
118 	ret = pm_ipi_send_common(proc, payload, IPI_BLOCKING);
119 
120 	bakery_lock_release(&pm_secure_lock);
121 
122 	return ret;
123 }
124 
125 
126 /**
127  * pm_ipi_buff_read() - Reads IPI response after remote processor has handled
128  *			interrupt
129  * @proc	Pointer to the processor who is waiting and reading response
130  * @value	Used to return value from IPI buffer element (optional)
131  * @count	Number of values to return in @value
132  *
133  * @return	Returns status, either success or error+reason
134  */
pm_ipi_buff_read(const struct pm_proc * proc,uint32_t * value,size_t count)135 static enum pm_ret_status pm_ipi_buff_read(const struct pm_proc *proc,
136 					   uint32_t *value, size_t count)
137 {
138 	size_t i;
139 #if IPI_CRC_CHECK
140 	size_t j;
141 	uint32_t response_payload[PAYLOAD_ARG_CNT];
142 #endif
143 	uintptr_t buffer_base = proc->ipi->buffer_base +
144 				IPI_BUFFER_TARGET_REMOTE_OFFSET +
145 				IPI_BUFFER_RESP_OFFSET;
146 
147 	/*
148 	 * Read response from IPI buffer
149 	 * buf-0: success or error+reason
150 	 * buf-1: value
151 	 * buf-2: unused
152 	 * buf-3: unused
153 	 */
154 	for (i = 1; i <= count; i++) {
155 		*value = mmio_read_32(buffer_base + (i * PAYLOAD_ARG_SIZE));
156 		value++;
157 	}
158 #if IPI_CRC_CHECK
159 	for (j = 0; j < PAYLOAD_ARG_CNT; j++) {
160 		response_payload[j] = mmio_read_32(buffer_base +
161 						(j * PAYLOAD_ARG_SIZE));
162 	}
163 
164 	if (response_payload[PAYLOAD_CRC_POS] !=
165 			calculate_crc(response_payload, IPI_W0_TO_W6_SIZE)) {
166 		NOTICE("ERROR in CRC response payload value:0x%x\n",
167 					response_payload[PAYLOAD_CRC_POS]);
168 	}
169 #endif
170 
171 	return mmio_read_32(buffer_base);
172 }
173 
174 /**
175  * pm_ipi_buff_read_callb() - Reads IPI response after remote processor has
176  *			      handled interrupt
177  * @value	Used to return value from IPI buffer element (optional)
178  * @count	Number of values to return in @value
179  *
180  * @return	Returns status, either success or error+reason
181  */
pm_ipi_buff_read_callb(uint32_t * value,size_t count)182 void pm_ipi_buff_read_callb(uint32_t *value, size_t count)
183 {
184 	size_t i;
185 #if IPI_CRC_CHECK
186 	size_t j;
187 	unsigned int response_payload[PAYLOAD_ARG_CNT] = {0};
188 #endif
189 	uintptr_t buffer_base = IPI_BUFFER_REMOTE_BASE +
190 				IPI_BUFFER_TARGET_LOCAL_OFFSET +
191 				IPI_BUFFER_REQ_OFFSET;
192 
193 	if (count > IPI_BUFFER_MAX_WORDS) {
194 		count = IPI_BUFFER_MAX_WORDS;
195 	}
196 
197 	for (i = 0; i <= count; i++) {
198 		*value = mmio_read_32(buffer_base + (i * PAYLOAD_ARG_SIZE));
199 		value++;
200 	}
201 #if IPI_CRC_CHECK
202 	for (j = 0; j < PAYLOAD_ARG_CNT; j++) {
203 		response_payload[j] = mmio_read_32(buffer_base +
204 						(j * PAYLOAD_ARG_SIZE));
205 	}
206 
207 	if (response_payload[PAYLOAD_CRC_POS] !=
208 			calculate_crc(response_payload, IPI_W0_TO_W6_SIZE)) {
209 		NOTICE("ERROR in CRC response payload value:0x%x\n",
210 					response_payload[PAYLOAD_CRC_POS]);
211 	}
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],uint32_t * 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 				    uint32_t *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 
240 	ret = ERROR_CODE_MASK & (pm_ipi_buff_read(proc, value, count));
241 
242 unlock:
243 	bakery_lock_release(&pm_secure_lock);
244 
245 	return ret;
246 }
247 
pm_ipi_irq_enable(const struct pm_proc * proc)248 void pm_ipi_irq_enable(const struct pm_proc *proc)
249 {
250 	ipi_mb_enable_irq(proc->ipi->local_ipi_id, proc->ipi->remote_ipi_id);
251 }
252 
pm_ipi_irq_clear(const struct pm_proc * proc)253 void pm_ipi_irq_clear(const struct pm_proc *proc)
254 {
255 	ipi_mb_ack(proc->ipi->local_ipi_id, proc->ipi->remote_ipi_id);
256 }
257 
pm_ipi_irq_status(const struct pm_proc * proc)258 uint32_t pm_ipi_irq_status(const struct pm_proc *proc)
259 {
260 	int32_t ret;
261 
262 	ret = ipi_mb_enquire_status(proc->ipi->local_ipi_id,
263 				    proc->ipi->remote_ipi_id);
264 	if (ret & IPI_MB_STATUS_RECV_PENDING) {
265 		return 1;
266 	} else {
267 		return 0;
268 	}
269 }
270 
271 #if IPI_CRC_CHECK
calculate_crc(uint32_t payload[PAYLOAD_ARG_CNT],uint32_t bufsize)272 uint32_t calculate_crc(uint32_t payload[PAYLOAD_ARG_CNT], uint32_t bufsize)
273 {
274 	uint32_t crcinit = CRC_INIT_VALUE;
275 	uint32_t order   = CRC_ORDER;
276 	uint32_t polynom = CRC_POLYNOM;
277 	uint32_t i, j, c, bit, datain, crcmask, crchighbit;
278 	uint32_t crc = crcinit;
279 
280 	crcmask = ((uint32_t)((1U << (order - 1U)) - 1U) << 1U) | 1U;
281 	crchighbit = (uint32_t)(1U << (order - 1U));
282 
283 	for (i = 0U; i < bufsize; i++) {
284 		datain = mmio_read_8((unsigned long)payload + i);
285 		c = datain;
286 		j = 0x80U;
287 		while (j != 0U) {
288 			bit = crc & crchighbit;
289 			crc <<= 1U;
290 			if (0U != (c & j))
291 				bit ^= crchighbit;
292 			if (bit != 0U)
293 				crc ^= polynom;
294 			j >>= 1U;
295 		}
296 		crc &= crcmask;
297 	}
298 	return crc;
299 }
300 #endif
301