1 /*
2  * Copyright (c) 2016-2019, 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/debug.h>
18 #include <common/runtime_svc.h>
19 #include <context.h>
20 #include <drivers/console.h>
21 #include <lib/el3_runtime/context_mgmt.h>
22 #include <lib/pmf/pmf.h>
23 #include <lib/psci/psci.h>
24 #include <lib/runtime_instr.h>
25 #include <lib/utils.h>
26 #include <plat/common/platform.h>
27 #include <platform_sp_min.h>
28 #include <services/std_svc.h>
29 #include <smccc_helpers.h>
30 
31 #include "sp_min_private.h"
32 
33 #if ENABLE_RUNTIME_INSTRUMENTATION
PMF_REGISTER_SERVICE_SMC(rt_instr_svc,PMF_RT_INSTR_SVC_ID,RT_INSTR_TOTAL_IDS,PMF_STORE_ENABLE)34 PMF_REGISTER_SERVICE_SMC(rt_instr_svc, PMF_RT_INSTR_SVC_ID,
35 	RT_INSTR_TOTAL_IDS, PMF_STORE_ENABLE)
36 #endif
37 
38 /* Pointers to per-core cpu contexts */
39 static void *sp_min_cpu_ctx_ptr[PLATFORM_CORE_COUNT];
40 
41 /* SP_MIN only stores the non secure smc context */
42 static smc_ctx_t sp_min_smc_context[PLATFORM_CORE_COUNT];
43 
44 /******************************************************************************
45  * Define the smccc helper library APIs
46  *****************************************************************************/
47 void *smc_get_ctx(unsigned int security_state)
48 {
49 	assert(security_state == NON_SECURE);
50 	return &sp_min_smc_context[plat_my_core_pos()];
51 }
52 
smc_set_next_ctx(unsigned int security_state)53 void smc_set_next_ctx(unsigned int security_state)
54 {
55 	assert(security_state == NON_SECURE);
56 	/* SP_MIN stores only non secure smc context. Nothing to do here */
57 }
58 
smc_get_next_ctx(void)59 void *smc_get_next_ctx(void)
60 {
61 	return &sp_min_smc_context[plat_my_core_pos()];
62 }
63 
64 /*******************************************************************************
65  * This function returns a pointer to the most recent 'cpu_context' structure
66  * for the calling CPU that was set as the context for the specified security
67  * state. NULL is returned if no such structure has been specified.
68  ******************************************************************************/
cm_get_context(uint32_t security_state)69 void *cm_get_context(uint32_t security_state)
70 {
71 	assert(security_state == NON_SECURE);
72 	return sp_min_cpu_ctx_ptr[plat_my_core_pos()];
73 }
74 
75 /*******************************************************************************
76  * This function sets the pointer to the current 'cpu_context' structure for the
77  * specified security state for the calling CPU
78  ******************************************************************************/
cm_set_context(void * context,uint32_t security_state)79 void cm_set_context(void *context, uint32_t security_state)
80 {
81 	assert(security_state == NON_SECURE);
82 	sp_min_cpu_ctx_ptr[plat_my_core_pos()] = context;
83 }
84 
85 /*******************************************************************************
86  * This function returns a pointer to the most recent 'cpu_context' structure
87  * for the CPU identified by `cpu_idx` that was set as the context for the
88  * specified security state. NULL is returned if no such structure has been
89  * specified.
90  ******************************************************************************/
cm_get_context_by_index(unsigned int cpu_idx,unsigned int security_state)91 void *cm_get_context_by_index(unsigned int cpu_idx,
92 				unsigned int security_state)
93 {
94 	assert(security_state == NON_SECURE);
95 	return sp_min_cpu_ctx_ptr[cpu_idx];
96 }
97 
98 /*******************************************************************************
99  * This function sets the pointer to the current 'cpu_context' structure for the
100  * specified security state for the CPU identified by CPU index.
101  ******************************************************************************/
cm_set_context_by_index(unsigned int cpu_idx,void * context,unsigned int security_state)102 void cm_set_context_by_index(unsigned int cpu_idx, void *context,
103 				unsigned int security_state)
104 {
105 	assert(security_state == NON_SECURE);
106 	sp_min_cpu_ctx_ptr[cpu_idx] = context;
107 }
108 
copy_cpu_ctx_to_smc_stx(const regs_t * cpu_reg_ctx,smc_ctx_t * next_smc_ctx)109 static void copy_cpu_ctx_to_smc_stx(const regs_t *cpu_reg_ctx,
110 				smc_ctx_t *next_smc_ctx)
111 {
112 	next_smc_ctx->r0 = read_ctx_reg(cpu_reg_ctx, CTX_GPREG_R0);
113 	next_smc_ctx->r1 = read_ctx_reg(cpu_reg_ctx, CTX_GPREG_R1);
114 	next_smc_ctx->r2 = read_ctx_reg(cpu_reg_ctx, CTX_GPREG_R2);
115 	next_smc_ctx->lr_mon = read_ctx_reg(cpu_reg_ctx, CTX_LR);
116 	next_smc_ctx->spsr_mon = read_ctx_reg(cpu_reg_ctx, CTX_SPSR);
117 	next_smc_ctx->scr = read_ctx_reg(cpu_reg_ctx, CTX_SCR);
118 }
119 
120 /*******************************************************************************
121  * This function invokes the PSCI library interface to initialize the
122  * non secure cpu context and copies the relevant cpu context register values
123  * to smc context. These registers will get programmed during `smc_exit`.
124  ******************************************************************************/
sp_min_prepare_next_image_entry(void)125 static void sp_min_prepare_next_image_entry(void)
126 {
127 	entry_point_info_t *next_image_info;
128 	cpu_context_t *ctx = cm_get_context(NON_SECURE);
129 	u_register_t ns_sctlr;
130 
131 	/* Program system registers to proceed to non-secure */
132 	next_image_info = sp_min_plat_get_bl33_ep_info();
133 	assert(next_image_info);
134 	assert(NON_SECURE == GET_SECURITY_STATE(next_image_info->h.attr));
135 
136 	INFO("SP_MIN: Preparing exit to normal world\n");
137 
138 	psci_prepare_next_non_secure_ctx(next_image_info);
139 	smc_set_next_ctx(NON_SECURE);
140 
141 	/* Copy r0, lr and spsr from cpu context to SMC context */
142 	copy_cpu_ctx_to_smc_stx(get_regs_ctx(cm_get_context(NON_SECURE)),
143 			smc_get_next_ctx());
144 
145 	/* Temporarily set the NS bit to access NS SCTLR */
146 	write_scr(read_scr() | SCR_NS_BIT);
147 	isb();
148 	ns_sctlr = read_ctx_reg(get_regs_ctx(ctx), CTX_NS_SCTLR);
149 	write_sctlr(ns_sctlr);
150 	isb();
151 
152 	write_scr(read_scr() & ~SCR_NS_BIT);
153 	isb();
154 }
155 
156 /******************************************************************************
157  * Implement the ARM Standard Service function to get arguments for a
158  * particular service.
159  *****************************************************************************/
get_arm_std_svc_args(unsigned int svc_mask)160 uintptr_t get_arm_std_svc_args(unsigned int svc_mask)
161 {
162 	/* Setup the arguments for PSCI Library */
163 	DEFINE_STATIC_PSCI_LIB_ARGS_V1(psci_args, sp_min_warm_entrypoint);
164 
165 	/* PSCI is the only ARM Standard Service implemented */
166 	assert(svc_mask == PSCI_FID_MASK);
167 
168 	return (uintptr_t)&psci_args;
169 }
170 
171 /******************************************************************************
172  * The SP_MIN main function. Do the platform and PSCI Library setup. Also
173  * initialize the runtime service framework.
174  *****************************************************************************/
sp_min_main(void)175 void sp_min_main(void)
176 {
177 	NOTICE("SP_MIN: %s\n", version_string);
178 	NOTICE("SP_MIN: %s\n", build_message);
179 
180 	/* Perform the SP_MIN platform setup */
181 	sp_min_platform_setup();
182 
183 	/* Initialize the runtime services e.g. psci */
184 	INFO("SP_MIN: Initializing runtime services\n");
185 	runtime_svc_init();
186 
187 	/*
188 	 * We are ready to enter the next EL. Prepare entry into the image
189 	 * corresponding to the desired security state after the next ERET.
190 	 */
191 	sp_min_prepare_next_image_entry();
192 
193 	/*
194 	 * Perform any platform specific runtime setup prior to cold boot exit
195 	 * from SP_MIN.
196 	 */
197 	sp_min_plat_runtime_setup();
198 
199 	console_flush();
200 }
201 
202 /******************************************************************************
203  * This function is invoked during warm boot. Invoke the PSCI library
204  * warm boot entry point which takes care of Architectural and platform setup/
205  * restore. Copy the relevant cpu_context register values to smc context which
206  * will get programmed during `smc_exit`.
207  *****************************************************************************/
sp_min_warm_boot(void)208 void sp_min_warm_boot(void)
209 {
210 	smc_ctx_t *next_smc_ctx;
211 	cpu_context_t *ctx = cm_get_context(NON_SECURE);
212 	u_register_t ns_sctlr;
213 
214 	psci_warmboot_entrypoint();
215 
216 	smc_set_next_ctx(NON_SECURE);
217 
218 	next_smc_ctx = smc_get_next_ctx();
219 	zeromem(next_smc_ctx, sizeof(smc_ctx_t));
220 
221 	copy_cpu_ctx_to_smc_stx(get_regs_ctx(cm_get_context(NON_SECURE)),
222 			next_smc_ctx);
223 
224 	/* Temporarily set the NS bit to access NS SCTLR */
225 	write_scr(read_scr() | SCR_NS_BIT);
226 	isb();
227 	ns_sctlr = read_ctx_reg(get_regs_ctx(ctx), CTX_NS_SCTLR);
228 	write_sctlr(ns_sctlr);
229 	isb();
230 
231 	write_scr(read_scr() & ~SCR_NS_BIT);
232 	isb();
233 }
234 
235 #if SP_MIN_WITH_SECURE_FIQ
236 /******************************************************************************
237  * This function is invoked on secure interrupts. By construction of the
238  * SP_MIN, secure interrupts can only be handled when core executes in non
239  * secure state.
240  *****************************************************************************/
sp_min_fiq(void)241 void sp_min_fiq(void)
242 {
243 	uint32_t id;
244 
245 	id = plat_ic_acknowledge_interrupt();
246 	sp_min_plat_fiq_handler(id);
247 	plat_ic_end_of_interrupt(id);
248 }
249 #endif /* SP_MIN_WITH_SECURE_FIQ */
250