1 /*
2  * Copyright (c) 2016-2024, Arm Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <assert.h>
8 #include <stddef.h>
9 #include <stdint.h>
10 #include <string.h>
11 
12 #include <platform_def.h>
13 
14 #include <arch.h>
15 #include <arch_helpers.h>
16 #include <common/bl_common.h>
17 #include <common/build_message.h>
18 #include <common/debug.h>
19 #include <common/runtime_svc.h>
20 #include <context.h>
21 #include <drivers/console.h>
22 #include <lib/el3_runtime/context_mgmt.h>
23 #include <lib/pmf/pmf.h>
24 #include <lib/psci/psci.h>
25 #include <lib/runtime_instr.h>
26 #include <lib/utils.h>
27 #include <plat/common/platform.h>
28 #include <platform_sp_min.h>
29 #include <services/std_svc.h>
30 #include <smccc_helpers.h>
31 
32 #include "sp_min_private.h"
33 
34 #if ENABLE_RUNTIME_INSTRUMENTATION
PMF_REGISTER_SERVICE_SMC(rt_instr_svc,PMF_RT_INSTR_SVC_ID,RT_INSTR_TOTAL_IDS,PMF_STORE_ENABLE)35 PMF_REGISTER_SERVICE_SMC(rt_instr_svc, PMF_RT_INSTR_SVC_ID,
36 	RT_INSTR_TOTAL_IDS, PMF_STORE_ENABLE)
37 #endif
38 
39 /* Pointers to per-core cpu contexts */
40 static void *sp_min_cpu_ctx_ptr[PLATFORM_CORE_COUNT];
41 
42 /* SP_MIN only stores the non secure smc context */
43 static smc_ctx_t sp_min_smc_context[PLATFORM_CORE_COUNT];
44 
45 /******************************************************************************
46  * Define the smccc helper library APIs
47  *****************************************************************************/
48 void *smc_get_ctx(unsigned int security_state)
49 {
50 	assert(security_state == NON_SECURE);
51 	return &sp_min_smc_context[plat_my_core_pos()];
52 }
53 
smc_set_next_ctx(unsigned int security_state)54 void smc_set_next_ctx(unsigned int security_state)
55 {
56 	assert(security_state == NON_SECURE);
57 	/* SP_MIN stores only non secure smc context. Nothing to do here */
58 }
59 
smc_get_next_ctx(void)60 void *smc_get_next_ctx(void)
61 {
62 	return &sp_min_smc_context[plat_my_core_pos()];
63 }
64 
65 /*******************************************************************************
66  * This function returns a pointer to the most recent 'cpu_context' structure
67  * for the calling CPU that was set as the context for the specified security
68  * state. NULL is returned if no such structure has been specified.
69  ******************************************************************************/
cm_get_context(uint32_t security_state)70 void *cm_get_context(uint32_t security_state)
71 {
72 	assert(security_state == NON_SECURE);
73 	return sp_min_cpu_ctx_ptr[plat_my_core_pos()];
74 }
75 
76 /*******************************************************************************
77  * This function sets the pointer to the current 'cpu_context' structure for the
78  * specified security state for the calling CPU
79  ******************************************************************************/
cm_set_context(void * context,uint32_t security_state)80 void cm_set_context(void *context, uint32_t security_state)
81 {
82 	assert(security_state == NON_SECURE);
83 	sp_min_cpu_ctx_ptr[plat_my_core_pos()] = context;
84 }
85 
86 /*******************************************************************************
87  * This function returns a pointer to the most recent 'cpu_context' structure
88  * for the CPU identified by `cpu_idx` that was set as the context for the
89  * specified security state. NULL is returned if no such structure has been
90  * specified.
91  ******************************************************************************/
cm_get_context_by_index(unsigned int cpu_idx,unsigned int security_state)92 void *cm_get_context_by_index(unsigned int cpu_idx,
93 				unsigned int security_state)
94 {
95 	assert(security_state == NON_SECURE);
96 	return sp_min_cpu_ctx_ptr[cpu_idx];
97 }
98 
99 /*******************************************************************************
100  * This function sets the pointer to the current 'cpu_context' structure for the
101  * specified security state for the CPU identified by CPU index.
102  ******************************************************************************/
cm_set_context_by_index(unsigned int cpu_idx,void * context,unsigned int security_state)103 void cm_set_context_by_index(unsigned int cpu_idx, void *context,
104 				unsigned int security_state)
105 {
106 	assert(security_state == NON_SECURE);
107 	sp_min_cpu_ctx_ptr[cpu_idx] = context;
108 }
109 
copy_cpu_ctx_to_smc_stx(const regs_t * cpu_reg_ctx,smc_ctx_t * next_smc_ctx)110 static void copy_cpu_ctx_to_smc_stx(const regs_t *cpu_reg_ctx,
111 				smc_ctx_t *next_smc_ctx)
112 {
113 	next_smc_ctx->r0 = read_ctx_reg(cpu_reg_ctx, CTX_GPREG_R0);
114 	next_smc_ctx->r1 = read_ctx_reg(cpu_reg_ctx, CTX_GPREG_R1);
115 	next_smc_ctx->r2 = read_ctx_reg(cpu_reg_ctx, CTX_GPREG_R2);
116 	next_smc_ctx->lr_mon = read_ctx_reg(cpu_reg_ctx, CTX_LR);
117 	next_smc_ctx->spsr_mon = read_ctx_reg(cpu_reg_ctx, CTX_SPSR);
118 	next_smc_ctx->scr = read_ctx_reg(cpu_reg_ctx, CTX_SCR);
119 }
120 
121 /*******************************************************************************
122  * This function invokes the PSCI library interface to initialize the
123  * non secure cpu context and copies the relevant cpu context register values
124  * to smc context. These registers will get programmed during `smc_exit`.
125  ******************************************************************************/
sp_min_prepare_next_image_entry(void)126 static void sp_min_prepare_next_image_entry(void)
127 {
128 	entry_point_info_t *next_image_info;
129 	cpu_context_t *ctx = cm_get_context(NON_SECURE);
130 	u_register_t ns_sctlr;
131 
132 	/* Program system registers to proceed to non-secure */
133 	next_image_info = sp_min_plat_get_bl33_ep_info();
134 	assert(next_image_info);
135 	assert(NON_SECURE == GET_SECURITY_STATE(next_image_info->h.attr));
136 
137 	INFO("SP_MIN: Preparing exit to normal world\n");
138 	print_entry_point_info(next_image_info);
139 
140 	psci_prepare_next_non_secure_ctx(next_image_info);
141 	smc_set_next_ctx(NON_SECURE);
142 
143 	/* Copy r0, lr and spsr from cpu context to SMC context */
144 	copy_cpu_ctx_to_smc_stx(get_regs_ctx(cm_get_context(NON_SECURE)),
145 			smc_get_next_ctx());
146 
147 	/* Temporarily set the NS bit to access NS SCTLR */
148 	write_scr(read_scr() | SCR_NS_BIT);
149 	isb();
150 	ns_sctlr = read_ctx_reg(get_regs_ctx(ctx), CTX_NS_SCTLR);
151 	write_sctlr(ns_sctlr);
152 	isb();
153 
154 	write_scr(read_scr() & ~SCR_NS_BIT);
155 	isb();
156 }
157 
158 /******************************************************************************
159  * Implement the ARM Standard Service function to get arguments for a
160  * particular service.
161  *****************************************************************************/
get_arm_std_svc_args(unsigned int svc_mask)162 uintptr_t get_arm_std_svc_args(unsigned int svc_mask)
163 {
164 	/* Setup the arguments for PSCI Library */
165 	DEFINE_STATIC_PSCI_LIB_ARGS_V1(psci_args, sp_min_warm_entrypoint);
166 
167 	/* PSCI is the only ARM Standard Service implemented */
168 	assert(svc_mask == PSCI_FID_MASK);
169 
170 	return (uintptr_t)&psci_args;
171 }
172 
173 /******************************************************************************
174  * The SP_MIN setup function. Calls platforms init functions
175  *****************************************************************************/
sp_min_setup(u_register_t arg0,u_register_t arg1,u_register_t arg2,u_register_t arg3)176 void sp_min_setup(u_register_t arg0, u_register_t arg1, u_register_t arg2,
177 		  u_register_t arg3)
178 {
179 	/* Enable early console if EARLY_CONSOLE flag is enabled */
180 	plat_setup_early_console();
181 
182 	/* Perform early platform-specific setup */
183 	sp_min_early_platform_setup2(arg0, arg1, arg2, arg3);
184 	sp_min_plat_arch_setup();
185 }
186 
187 /******************************************************************************
188  * The SP_MIN main function. Do the platform and PSCI Library setup. Also
189  * initialize the runtime service framework.
190  *****************************************************************************/
sp_min_main(void)191 void sp_min_main(void)
192 {
193 	NOTICE("SP_MIN: %s\n", build_version_string);
194 	NOTICE("SP_MIN: %s\n", build_message);
195 
196 	/* Perform the SP_MIN platform setup */
197 	sp_min_platform_setup();
198 
199 	/* Initialize the runtime services e.g. psci */
200 	INFO("SP_MIN: Initializing runtime services\n");
201 	runtime_svc_init();
202 
203 	/*
204 	 * We are ready to enter the next EL. Prepare entry into the image
205 	 * corresponding to the desired security state after the next ERET.
206 	 */
207 	sp_min_prepare_next_image_entry();
208 
209 	/*
210 	 * Perform any platform specific runtime setup prior to cold boot exit
211 	 * from SP_MIN.
212 	 */
213 	sp_min_plat_runtime_setup();
214 
215 	console_flush();
216 }
217 
218 /******************************************************************************
219  * This function is invoked during warm boot. Invoke the PSCI library
220  * warm boot entry point which takes care of Architectural and platform setup/
221  * restore. Copy the relevant cpu_context register values to smc context which
222  * will get programmed during `smc_exit`.
223  *****************************************************************************/
sp_min_warm_boot(void)224 void sp_min_warm_boot(void)
225 {
226 	smc_ctx_t *next_smc_ctx;
227 	cpu_context_t *ctx = cm_get_context(NON_SECURE);
228 	u_register_t ns_sctlr;
229 
230 	psci_warmboot_entrypoint();
231 
232 	smc_set_next_ctx(NON_SECURE);
233 
234 	next_smc_ctx = smc_get_next_ctx();
235 	zeromem(next_smc_ctx, sizeof(smc_ctx_t));
236 
237 	copy_cpu_ctx_to_smc_stx(get_regs_ctx(cm_get_context(NON_SECURE)),
238 			next_smc_ctx);
239 
240 	/* Temporarily set the NS bit to access NS SCTLR */
241 	write_scr(read_scr() | SCR_NS_BIT);
242 	isb();
243 	ns_sctlr = read_ctx_reg(get_regs_ctx(ctx), CTX_NS_SCTLR);
244 	write_sctlr(ns_sctlr);
245 	isb();
246 
247 	write_scr(read_scr() & ~SCR_NS_BIT);
248 	isb();
249 }
250 
251 #if SP_MIN_WITH_SECURE_FIQ
252 /******************************************************************************
253  * This function is invoked on secure interrupts. By construction of the
254  * SP_MIN, secure interrupts can only be handled when core executes in non
255  * secure state.
256  *****************************************************************************/
sp_min_fiq(void)257 void sp_min_fiq(void)
258 {
259 	uint32_t id;
260 
261 	id = plat_ic_acknowledge_interrupt();
262 	sp_min_plat_fiq_handler(id);
263 	plat_ic_end_of_interrupt(id);
264 }
265 #endif /* SP_MIN_WITH_SECURE_FIQ */
266