1 /*
2  * Copyright (c) 2022, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <assert.h>
8 #include <errno.h>
9 
10 #include <lib/el3_runtime/context_mgmt.h>
11 #include <lib/spinlock.h>
12 #include <plat/common/common_def.h>
13 #include <plat/common/platform.h>
14 #include <services/ffa_svc.h>
15 #include "spmc.h"
16 
17 #include <platform_def.h>
18 
19 /*******************************************************************************
20  * spmc_build_pm_message
21  *
22  * Builds an SPMC to SP direct message request.
23  ******************************************************************************/
spmc_build_pm_message(gp_regs_t * gpregs,unsigned long long message,uint8_t pm_msg_type,uint16_t sp_id)24 static void spmc_build_pm_message(gp_regs_t *gpregs,
25 				  unsigned long long message,
26 				  uint8_t pm_msg_type,
27 				  uint16_t sp_id)
28 {
29 	write_ctx_reg(gpregs, CTX_GPREG_X0, FFA_MSG_SEND_DIRECT_REQ_SMC32);
30 	write_ctx_reg(gpregs, CTX_GPREG_X1,
31 		      (FFA_SPMC_ID << FFA_DIRECT_MSG_SOURCE_SHIFT) |
32 		      sp_id);
33 	write_ctx_reg(gpregs, CTX_GPREG_X2, FFA_FWK_MSG_BIT |
34 		      (pm_msg_type & FFA_FWK_MSG_MASK));
35 	write_ctx_reg(gpregs, CTX_GPREG_X3, message);
36 }
37 
38 /*******************************************************************************
39  * This CPU has been turned on. Enter the SP to initialise S-EL1.
40  ******************************************************************************/
spmc_cpu_on_finish_handler(u_register_t unused)41 static void spmc_cpu_on_finish_handler(u_register_t unused)
42 {
43 	struct secure_partition_desc *sp = spmc_get_current_sp_ctx();
44 	struct sp_exec_ctx *ec;
45 	unsigned int linear_id = plat_my_core_pos();
46 	entry_point_info_t sec_ec_ep_info = {0};
47 	uint64_t rc;
48 
49 	/* Sanity check for a NULL pointer dereference. */
50 	assert(sp != NULL);
51 
52 	/* Initialize entry point information for the SP. */
53 	SET_PARAM_HEAD(&sec_ec_ep_info, PARAM_EP, VERSION_1,
54 		       SECURE | EP_ST_ENABLE);
55 
56 	/*
57 	 * Check if the primary execution context registered an entry point else
58 	 * bail out early.
59 	 * TODO: Add support for boot reason in manifest to allow jumping to
60 	 * entrypoint into the primary execution context.
61 	 */
62 	if (sp->secondary_ep == 0) {
63 		WARN("%s: No secondary ep on core%u\n", __func__, linear_id);
64 		return;
65 	}
66 
67 	sec_ec_ep_info.pc = sp->secondary_ep;
68 
69 	/*
70 	 * Setup and initialise the SP execution context on this physical cpu.
71 	 */
72 	spmc_el1_sp_setup(sp, &sec_ec_ep_info);
73 	spmc_sp_common_ep_commit(sp, &sec_ec_ep_info);
74 
75 	/* Obtain a reference to the SP execution context. */
76 	ec = spmc_get_sp_ec(sp);
77 
78 	/*
79 	 * TODO: Should we do some PM related state tracking of the SP execution
80 	 * context here?
81 	 */
82 
83 	/* Update the runtime model and state of the partition. */
84 	ec->rt_model = RT_MODEL_INIT;
85 	ec->rt_state = RT_STATE_RUNNING;
86 
87 	INFO("SP (0x%x) init start on core%u.\n", sp->sp_id, linear_id);
88 
89 	rc = spmc_sp_synchronous_entry(ec);
90 	if (rc != 0ULL) {
91 		ERROR("%s failed (%lu) on CPU%u\n", __func__, rc, linear_id);
92 	}
93 
94 	/* Update the runtime state of the partition. */
95 	ec->rt_state = RT_STATE_WAITING;
96 
97 	VERBOSE("CPU %u on!\n", linear_id);
98 }
99 /*******************************************************************************
100  * Helper function to send a FF-A power management message to an SP.
101  ******************************************************************************/
spmc_send_pm_msg(uint8_t pm_msg_type,unsigned long long psci_event)102 static int32_t spmc_send_pm_msg(uint8_t pm_msg_type,
103 				unsigned long long psci_event)
104 {
105 	struct secure_partition_desc *sp = spmc_get_current_sp_ctx();
106 	struct sp_exec_ctx *ec;
107 	gp_regs_t *gpregs_ctx;
108 	unsigned int linear_id = plat_my_core_pos();
109 	u_register_t resp;
110 	uint64_t rc;
111 
112 	/* Obtain a reference to the SP execution context. */
113 	ec = spmc_get_sp_ec(sp);
114 
115 	/*
116 	 * TODO: Should we do some PM related state tracking of the SP execution
117 	 * context here?
118 	 */
119 
120 	/*
121 	 * Build an SPMC to SP direct message request.
122 	 * Note that x4-x6 should be populated with the original PSCI arguments.
123 	 */
124 	spmc_build_pm_message(get_gpregs_ctx(&ec->cpu_ctx),
125 			      psci_event,
126 			      pm_msg_type,
127 			      sp->sp_id);
128 
129 	/* Sanity check partition state. */
130 	assert(ec->rt_state == RT_STATE_WAITING);
131 
132 	/* Update the runtime model and state of the partition. */
133 	ec->rt_model = RT_MODEL_DIR_REQ;
134 	ec->rt_state = RT_STATE_RUNNING;
135 
136 	rc = spmc_sp_synchronous_entry(ec);
137 	if (rc != 0ULL) {
138 		ERROR("%s failed (%lu) on CPU%u.\n", __func__, rc, linear_id);
139 		assert(false);
140 		return -EINVAL;
141 	}
142 
143 	/*
144 	 * Validate we receive an expected response from the SP.
145 	 * TODO: We don't currently support aborting an SP in the scenario
146 	 * where it is misbehaving so assert these conditions are not
147 	 * met for now.
148 	 */
149 	gpregs_ctx = get_gpregs_ctx(&ec->cpu_ctx);
150 
151 	/* Expect a direct message response from the SP. */
152 	resp = read_ctx_reg(gpregs_ctx, CTX_GPREG_X0);
153 	if (resp != FFA_MSG_SEND_DIRECT_RESP_SMC32) {
154 		ERROR("%s invalid SP response (%lx).\n", __func__, resp);
155 		assert(false);
156 		return -EINVAL;
157 	}
158 
159 	/* Ensure the sender and receiver are populated correctly. */
160 	resp = read_ctx_reg(gpregs_ctx, CTX_GPREG_X1);
161 	if (!(ffa_endpoint_source(resp) == sp->sp_id &&
162 	      ffa_endpoint_destination(resp) == FFA_SPMC_ID)) {
163 		ERROR("%s invalid src/dst response (%lx).\n", __func__, resp);
164 		assert(false);
165 		return -EINVAL;
166 	}
167 
168 	/* Expect a PM message response from the SP. */
169 	resp = read_ctx_reg(gpregs_ctx, CTX_GPREG_X2);
170 	if ((resp & FFA_FWK_MSG_BIT) == 0U ||
171 	    ((resp & FFA_FWK_MSG_MASK) != FFA_PM_MSG_PM_RESP)) {
172 		ERROR("%s invalid PM response (%lx).\n", __func__, resp);
173 		assert(false);
174 		return -EINVAL;
175 	}
176 
177 	/* Update the runtime state of the partition. */
178 	ec->rt_state = RT_STATE_WAITING;
179 
180 	/* Return the status code returned by the SP */
181 	return read_ctx_reg(gpregs_ctx, CTX_GPREG_X3);
182 }
183 
184 /*******************************************************************************
185  * spmc_cpu_suspend_finish_handler
186  ******************************************************************************/
spmc_cpu_suspend_finish_handler(u_register_t unused)187 static void spmc_cpu_suspend_finish_handler(u_register_t unused)
188 {
189 	struct secure_partition_desc *sp = spmc_get_current_sp_ctx();
190 	unsigned int linear_id = plat_my_core_pos();
191 	int32_t rc;
192 
193 	/* Sanity check for a NULL pointer dereference. */
194 	assert(sp != NULL);
195 
196 	/*
197 	 * Check if the SP has subscribed for this power management message.
198 	 * If not then we don't have anything else to do here.
199 	 */
200 	if ((sp->pwr_mgmt_msgs & FFA_PM_MSG_SUB_CPU_SUSPEND_RESUME) == 0U) {
201 		goto exit;
202 	}
203 
204 	rc = spmc_send_pm_msg(FFA_PM_MSG_WB_REQ, FFA_WB_TYPE_NOTS2RAM);
205 	if (rc < 0) {
206 		ERROR("%s failed (%d) on CPU%u\n", __func__, rc, linear_id);
207 		return;
208 	}
209 
210 exit:
211 	VERBOSE("CPU %u resumed!\n", linear_id);
212 }
213 
214 /*******************************************************************************
215  * spmc_cpu_suspend_handler
216  ******************************************************************************/
spmc_cpu_suspend_handler(u_register_t unused)217 static void spmc_cpu_suspend_handler(u_register_t unused)
218 {
219 	struct secure_partition_desc *sp = spmc_get_current_sp_ctx();
220 	unsigned int linear_id = plat_my_core_pos();
221 	int32_t rc;
222 
223 	/* Sanity check for a NULL pointer dereference. */
224 	assert(sp != NULL);
225 
226 	/*
227 	 * Check if the SP has subscribed for this power management message.
228 	 * If not then we don't have anything else to do here.
229 	 */
230 	if ((sp->pwr_mgmt_msgs & FFA_PM_MSG_SUB_CPU_SUSPEND) == 0U) {
231 		goto exit;
232 	}
233 
234 	rc = spmc_send_pm_msg(FFA_FWK_MSG_PSCI, PSCI_CPU_SUSPEND_AARCH64);
235 	if (rc < 0) {
236 		ERROR("%s failed (%d) on CPU%u\n", __func__, rc, linear_id);
237 		return;
238 	}
239 exit:
240 	VERBOSE("CPU %u suspend!\n", linear_id);
241 }
242 
243 /*******************************************************************************
244  * spmc_cpu_off_handler
245  ******************************************************************************/
spmc_cpu_off_handler(u_register_t unused)246 static int32_t spmc_cpu_off_handler(u_register_t unused)
247 {
248 	struct secure_partition_desc *sp = spmc_get_current_sp_ctx();
249 	unsigned int linear_id = plat_my_core_pos();
250 	int32_t ret = 0;
251 
252 	/* Sanity check for a NULL pointer dereference. */
253 	assert(sp != NULL);
254 
255 	/*
256 	 * Check if the SP has subscribed for this power management message.
257 	 * If not then we don't have anything else to do here.
258 	 */
259 	if ((sp->pwr_mgmt_msgs & FFA_PM_MSG_SUB_CPU_OFF) == 0U) {
260 		goto exit;
261 	}
262 
263 	ret = spmc_send_pm_msg(FFA_FWK_MSG_PSCI, PSCI_CPU_OFF);
264 	if (ret < 0) {
265 		ERROR("%s failed (%d) on CPU%u\n", __func__, ret, linear_id);
266 		return ret;
267 	}
268 
269 exit:
270 	VERBOSE("CPU %u off!\n", linear_id);
271 	return ret;
272 }
273 
274 /*******************************************************************************
275  * Structure populated by the SPM Core to perform any bookkeeping before
276  * PSCI executes a power mgmt. operation.
277  ******************************************************************************/
278 const spd_pm_ops_t spmc_pm = {
279 	.svc_on_finish = spmc_cpu_on_finish_handler,
280 	.svc_off = spmc_cpu_off_handler,
281 	.svc_suspend = spmc_cpu_suspend_handler,
282 	.svc_suspend_finish = spmc_cpu_suspend_finish_handler
283 };
284