1 /*
2  * Copyright (c) 2020-2021, 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 #include <lib/el3_runtime/context_mgmt.h>
10 #include <lib/spinlock.h>
11 #include "spmd_private.h"
12 
13 static struct {
14 	bool secondary_ep_locked;
15 	uintptr_t secondary_ep;
16 	spinlock_t lock;
17 } g_spmd_pm;
18 
19 /*******************************************************************************
20  * spmd_build_spmc_message
21  *
22  * Builds an SPMD to SPMC direct message request.
23  ******************************************************************************/
spmd_build_spmc_message(gp_regs_t * gpregs,unsigned long long message)24 static void spmd_build_spmc_message(gp_regs_t *gpregs, unsigned long long message)
25 {
26 	write_ctx_reg(gpregs, CTX_GPREG_X0, FFA_MSG_SEND_DIRECT_REQ_SMC32);
27 	write_ctx_reg(gpregs, CTX_GPREG_X1,
28 		(SPMD_DIRECT_MSG_ENDPOINT_ID << FFA_DIRECT_MSG_SOURCE_SHIFT) |
29 		spmd_spmc_id_get());
30 	write_ctx_reg(gpregs, CTX_GPREG_X2, FFA_PARAM_MBZ);
31 	write_ctx_reg(gpregs, CTX_GPREG_X3, message);
32 }
33 
34 /*******************************************************************************
35  * spmd_pm_secondary_ep_register
36  ******************************************************************************/
spmd_pm_secondary_ep_register(uintptr_t entry_point)37 int spmd_pm_secondary_ep_register(uintptr_t entry_point)
38 {
39 	int ret = FFA_ERROR_INVALID_PARAMETER;
40 
41 	spin_lock(&g_spmd_pm.lock);
42 
43 	if (g_spmd_pm.secondary_ep_locked == true) {
44 		goto out;
45 	}
46 
47 	/*
48 	 * Check entry_point address is a PA within
49 	 * load_address <= entry_point < load_address + binary_size
50 	 */
51 	if (!spmd_check_address_in_binary_image(entry_point)) {
52 		ERROR("%s entry point is not within image boundaries\n",
53 			__func__);
54 		goto out;
55 	}
56 
57 	g_spmd_pm.secondary_ep = entry_point;
58 	g_spmd_pm.secondary_ep_locked = true;
59 
60 	VERBOSE("%s %lx\n", __func__, entry_point);
61 
62 	ret = 0;
63 
64 out:
65 	spin_unlock(&g_spmd_pm.lock);
66 
67 	return ret;
68 }
69 
70 /*******************************************************************************
71  * This CPU has been turned on. Enter SPMC to initialise S-EL1 or S-EL2. As part
72  * of the SPMC initialization path, they will initialize any SPs that they
73  * manage. Entry into SPMC is done after initialising minimal architectural
74  * state that guarantees safe execution.
75  ******************************************************************************/
spmd_cpu_on_finish_handler(u_register_t unused)76 static void spmd_cpu_on_finish_handler(u_register_t unused)
77 {
78 	entry_point_info_t *spmc_ep_info = spmd_spmc_ep_info_get();
79 	spmd_spm_core_context_t *ctx = spmd_get_context();
80 	unsigned int linear_id = plat_my_core_pos();
81 	uint64_t rc;
82 
83 	assert(ctx != NULL);
84 	assert(ctx->state != SPMC_STATE_ON);
85 	assert(spmc_ep_info != NULL);
86 
87 	spin_lock(&g_spmd_pm.lock);
88 
89 	/*
90 	 * Leave the possibility that the SPMC does not call
91 	 * FFA_SECONDARY_EP_REGISTER in which case re-use the
92 	 * primary core address for booting secondary cores.
93 	 */
94 	if (g_spmd_pm.secondary_ep_locked == true) {
95 		spmc_ep_info->pc = g_spmd_pm.secondary_ep;
96 	}
97 
98 	spin_unlock(&g_spmd_pm.lock);
99 
100 	cm_setup_context(&ctx->cpu_ctx, spmc_ep_info);
101 
102 	/* Mark CPU as initiating ON operation */
103 	ctx->state = SPMC_STATE_ON_PENDING;
104 
105 	rc = spmd_spm_core_sync_entry(ctx);
106 	if (rc != 0ULL) {
107 		ERROR("%s failed (%llu) on CPU%u\n", __func__, rc,
108 			linear_id);
109 		ctx->state = SPMC_STATE_OFF;
110 		return;
111 	}
112 
113 	ctx->state = SPMC_STATE_ON;
114 
115 	VERBOSE("CPU %u on!\n", linear_id);
116 }
117 
118 /*******************************************************************************
119  * spmd_cpu_off_handler
120  ******************************************************************************/
spmd_cpu_off_handler(u_register_t unused)121 static int32_t spmd_cpu_off_handler(u_register_t unused)
122 {
123 	spmd_spm_core_context_t *ctx = spmd_get_context();
124 	unsigned int linear_id = plat_my_core_pos();
125 	int64_t rc;
126 
127 	assert(ctx != NULL);
128 	assert(ctx->state != SPMC_STATE_OFF);
129 
130 	/* Build an SPMD to SPMC direct message request. */
131 	spmd_build_spmc_message(get_gpregs_ctx(&ctx->cpu_ctx), PSCI_CPU_OFF);
132 
133 	rc = spmd_spm_core_sync_entry(ctx);
134 	if (rc != 0ULL) {
135 		ERROR("%s failed (%llu) on CPU%u\n", __func__, rc, linear_id);
136 	}
137 
138 	/* Expect a direct message response from the SPMC. */
139 	u_register_t ffa_resp_func = read_ctx_reg(get_gpregs_ctx(&ctx->cpu_ctx),
140 						  CTX_GPREG_X0);
141 	if (ffa_resp_func != FFA_MSG_SEND_DIRECT_RESP_SMC32) {
142 		ERROR("%s invalid SPMC response (%lx).\n",
143 			__func__, ffa_resp_func);
144 		return -EINVAL;
145 	}
146 
147 	ctx->state = SPMC_STATE_OFF;
148 
149 	VERBOSE("CPU %u off!\n", linear_id);
150 
151 	return 0;
152 }
153 
154 /*******************************************************************************
155  * Structure populated by the SPM Dispatcher to perform any bookkeeping before
156  * PSCI executes a power mgmt. operation.
157  ******************************************************************************/
158 const spd_pm_ops_t spmd_pm = {
159 	.svc_on_finish = spmd_cpu_on_finish_handler,
160 	.svc_off = spmd_cpu_off_handler
161 };
162