1 /*
2  * Copyright (c) 2021-2024, 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 <inttypes.h>
10 #include <stdint.h>
11 #include <string.h>
12 
13 #include <arch_helpers.h>
14 #include <arch_features.h>
15 #include <bl31/bl31.h>
16 #include <common/debug.h>
17 #include <common/runtime_svc.h>
18 #include <context.h>
19 #include <lib/el3_runtime/context_mgmt.h>
20 #include <lib/el3_runtime/cpu_data.h>
21 #include <lib/el3_runtime/pubsub.h>
22 #include <lib/extensions/pmuv3.h>
23 #include <lib/extensions/sys_reg_trace.h>
24 #include <lib/gpt_rme/gpt_rme.h>
25 
26 #include <lib/spinlock.h>
27 #include <lib/utils.h>
28 #include <lib/xlat_tables/xlat_tables_v2.h>
29 #include <plat/common/common_def.h>
30 #include <plat/common/platform.h>
31 #include <platform_def.h>
32 #include <services/rmmd_svc.h>
33 #include <smccc_helpers.h>
34 #include <lib/extensions/sme.h>
35 #include <lib/extensions/sve.h>
36 #include "rmmd_initial_context.h"
37 #include "rmmd_private.h"
38 
39 /*******************************************************************************
40  * RMM boot failure flag
41  ******************************************************************************/
42 static bool rmm_boot_failed;
43 
44 /*******************************************************************************
45  * RMM context information.
46  ******************************************************************************/
47 rmmd_rmm_context_t rmm_context[PLATFORM_CORE_COUNT];
48 
49 /*******************************************************************************
50  * RMM entry point information. Discovered on the primary core and reused
51  * on secondary cores.
52  ******************************************************************************/
53 static entry_point_info_t *rmm_ep_info;
54 
55 /*******************************************************************************
56  * Static function declaration.
57  ******************************************************************************/
58 static int32_t rmm_init(void);
59 
60 /*******************************************************************************
61  * This function takes an RMM context pointer and performs a synchronous entry
62  * into it.
63  ******************************************************************************/
rmmd_rmm_sync_entry(rmmd_rmm_context_t * rmm_ctx)64 uint64_t rmmd_rmm_sync_entry(rmmd_rmm_context_t *rmm_ctx)
65 {
66 	uint64_t rc;
67 
68 	assert(rmm_ctx != NULL);
69 
70 	cm_set_context(&(rmm_ctx->cpu_ctx), REALM);
71 
72 	/* Restore the realm context assigned above */
73 	cm_el2_sysregs_context_restore(REALM);
74 	cm_set_next_eret_context(REALM);
75 
76 	/* Enter RMM */
77 	rc = rmmd_rmm_enter(&rmm_ctx->c_rt_ctx);
78 
79 	/*
80 	 * Save realm context. EL2 Non-secure context will be restored
81 	 * before exiting Non-secure world, therefore there is no need
82 	 * to clear EL2 context registers.
83 	 */
84 	cm_el2_sysregs_context_save(REALM);
85 
86 	return rc;
87 }
88 
89 /*******************************************************************************
90  * This function returns to the place where rmmd_rmm_sync_entry() was
91  * called originally.
92  ******************************************************************************/
rmmd_rmm_sync_exit(uint64_t rc)93 __dead2 void rmmd_rmm_sync_exit(uint64_t rc)
94 {
95 	rmmd_rmm_context_t *ctx = &rmm_context[plat_my_core_pos()];
96 
97 	/* Get context of the RMM in use by this CPU. */
98 	assert(cm_get_context(REALM) == &(ctx->cpu_ctx));
99 
100 	/*
101 	 * The RMMD must have initiated the original request through a
102 	 * synchronous entry into RMM. Jump back to the original C runtime
103 	 * context with the value of rc in x0;
104 	 */
105 	rmmd_rmm_exit(ctx->c_rt_ctx, rc);
106 
107 	panic();
108 }
109 
rmm_el2_context_init(el2_sysregs_t * regs)110 static void rmm_el2_context_init(el2_sysregs_t *regs)
111 {
112 	write_el2_ctx_common(regs, spsr_el2, REALM_SPSR_EL2);
113 	write_el2_ctx_common(regs, sctlr_el2, SCTLR_EL2_RES1);
114 }
115 
116 /*******************************************************************************
117  * Enable architecture extensions on first entry to Realm world.
118  ******************************************************************************/
119 
manage_extensions_realm(cpu_context_t * ctx)120 static void manage_extensions_realm(cpu_context_t *ctx)
121 {
122 	pmuv3_enable(ctx);
123 
124 	/*
125 	 * Enable access to TPIDR2_EL0 if SME/SME2 is enabled for Non Secure world.
126 	 */
127 	if (is_feat_sme_supported()) {
128 		sme_enable(ctx);
129 	}
130 }
131 
manage_extensions_realm_per_world(void)132 static void manage_extensions_realm_per_world(void)
133 {
134 	cm_el3_arch_init_per_world(&per_world_context[CPU_CONTEXT_REALM]);
135 
136 	if (is_feat_sve_supported()) {
137 	/*
138 	 * Enable SVE and FPU in realm context when it is enabled for NS.
139 	 * Realm manager must ensure that the SVE and FPU register
140 	 * contexts are properly managed.
141 	 */
142 		sve_enable_per_world(&per_world_context[CPU_CONTEXT_REALM]);
143 	}
144 
145 	/* NS can access this but Realm shouldn't */
146 	if (is_feat_sys_reg_trace_supported()) {
147 		sys_reg_trace_disable_per_world(&per_world_context[CPU_CONTEXT_REALM]);
148 	}
149 
150 	/*
151 	 * If SME/SME2 is supported and enabled for NS world, then disable trapping
152 	 * of SME instructions for Realm world. RMM will save/restore required
153 	 * registers that are shared with SVE/FPU so that Realm can use FPU or SVE.
154 	 */
155 	if (is_feat_sme_supported()) {
156 		sme_enable_per_world(&per_world_context[CPU_CONTEXT_REALM]);
157 	}
158 }
159 
160 /*******************************************************************************
161  * Jump to the RMM for the first time.
162  ******************************************************************************/
rmm_init(void)163 static int32_t rmm_init(void)
164 {
165 	long rc;
166 	rmmd_rmm_context_t *ctx = &rmm_context[plat_my_core_pos()];
167 
168 	INFO("RMM init start.\n");
169 
170 	/* Enable architecture extensions */
171 	manage_extensions_realm(&ctx->cpu_ctx);
172 
173 	manage_extensions_realm_per_world();
174 
175 	/* Initialize RMM EL2 context. */
176 	rmm_el2_context_init(&ctx->cpu_ctx.el2_sysregs_ctx);
177 
178 	rc = rmmd_rmm_sync_entry(ctx);
179 	if (rc != E_RMM_BOOT_SUCCESS) {
180 		ERROR("RMM init failed: %ld\n", rc);
181 		/* Mark the boot as failed for all the CPUs */
182 		rmm_boot_failed = true;
183 		return 0;
184 	}
185 
186 	INFO("RMM init end.\n");
187 
188 	return 1;
189 }
190 
191 /*******************************************************************************
192  * Load and read RMM manifest, setup RMM.
193  ******************************************************************************/
rmmd_setup(void)194 int rmmd_setup(void)
195 {
196 	size_t shared_buf_size __unused;
197 	uintptr_t shared_buf_base;
198 	uint32_t ep_attr;
199 	unsigned int linear_id = plat_my_core_pos();
200 	rmmd_rmm_context_t *rmm_ctx = &rmm_context[linear_id];
201 	struct rmm_manifest *manifest;
202 	int rc;
203 
204 	/* Make sure RME is supported. */
205 	assert(is_feat_rme_present());
206 
207 	rmm_ep_info = bl31_plat_get_next_image_ep_info(REALM);
208 	if (rmm_ep_info == NULL) {
209 		WARN("No RMM image provided by BL2 boot loader, Booting "
210 		     "device without RMM initialization. SMCs destined for "
211 		     "RMM will return SMC_UNK\n");
212 		return -ENOENT;
213 	}
214 
215 	/* Under no circumstances will this parameter be 0 */
216 	assert(rmm_ep_info->pc == RMM_BASE);
217 
218 	/* Initialise an entrypoint to set up the CPU context */
219 	ep_attr = EP_REALM;
220 	if ((read_sctlr_el3() & SCTLR_EE_BIT) != 0U) {
221 		ep_attr |= EP_EE_BIG;
222 	}
223 
224 	SET_PARAM_HEAD(rmm_ep_info, PARAM_EP, VERSION_1, ep_attr);
225 	rmm_ep_info->spsr = SPSR_64(MODE_EL2,
226 					MODE_SP_ELX,
227 					DISABLE_ALL_EXCEPTIONS);
228 
229 	shared_buf_size =
230 			plat_rmmd_get_el3_rmm_shared_mem(&shared_buf_base);
231 
232 	assert((shared_buf_size == SZ_4K) &&
233 					((void *)shared_buf_base != NULL));
234 
235 	/* Zero out and load the boot manifest at the beginning of the share area */
236 	manifest = (struct rmm_manifest *)shared_buf_base;
237 	(void)memset((void *)manifest, 0, sizeof(struct rmm_manifest));
238 
239 	rc = plat_rmmd_load_manifest(manifest);
240 	if (rc != 0) {
241 		ERROR("Error loading RMM Boot Manifest (%i)\n", rc);
242 		return rc;
243 	}
244 	flush_dcache_range((uintptr_t)shared_buf_base, shared_buf_size);
245 
246 	/*
247 	 * Prepare coldboot arguments for RMM:
248 	 * arg0: This CPUID (primary processor).
249 	 * arg1: Version for this Boot Interface.
250 	 * arg2: PLATFORM_CORE_COUNT.
251 	 * arg3: Base address for the EL3 <-> RMM shared area. The boot
252 	 *       manifest will be stored at the beginning of this area.
253 	 */
254 	rmm_ep_info->args.arg0 = linear_id;
255 	rmm_ep_info->args.arg1 = RMM_EL3_INTERFACE_VERSION;
256 	rmm_ep_info->args.arg2 = PLATFORM_CORE_COUNT;
257 	rmm_ep_info->args.arg3 = shared_buf_base;
258 
259 	/* Initialise RMM context with this entry point information */
260 	cm_setup_context(&rmm_ctx->cpu_ctx, rmm_ep_info);
261 
262 	INFO("RMM setup done.\n");
263 
264 	/* Register init function for deferred init.  */
265 	bl31_register_rmm_init(&rmm_init);
266 
267 	return 0;
268 }
269 
270 /*******************************************************************************
271  * Forward SMC to the other security state
272  ******************************************************************************/
rmmd_smc_forward(uint32_t src_sec_state,uint32_t dst_sec_state,uint64_t x0,uint64_t x1,uint64_t x2,uint64_t x3,uint64_t x4,void * handle)273 static uint64_t	rmmd_smc_forward(uint32_t src_sec_state,
274 				 uint32_t dst_sec_state, uint64_t x0,
275 				 uint64_t x1, uint64_t x2, uint64_t x3,
276 				 uint64_t x4, void *handle)
277 {
278 	cpu_context_t *ctx = cm_get_context(dst_sec_state);
279 
280 	/* Save incoming security state */
281 	cm_el2_sysregs_context_save(src_sec_state);
282 
283 	/* Restore outgoing security state */
284 	cm_el2_sysregs_context_restore(dst_sec_state);
285 	cm_set_next_eret_context(dst_sec_state);
286 
287 	/*
288 	 * As per SMCCCv1.2, we need to preserve x4 to x7 unless
289 	 * being used as return args. Hence we differentiate the
290 	 * onward and backward path. Support upto 8 args in the
291 	 * onward path and 4 args in return path.
292 	 * Register x4 will be preserved by RMM in case it is not
293 	 * used in return path.
294 	 */
295 	if (src_sec_state == NON_SECURE) {
296 		SMC_RET8(ctx, x0, x1, x2, x3, x4,
297 			 SMC_GET_GP(handle, CTX_GPREG_X5),
298 			 SMC_GET_GP(handle, CTX_GPREG_X6),
299 			 SMC_GET_GP(handle, CTX_GPREG_X7));
300 	}
301 
302 	SMC_RET5(ctx, x0, x1, x2, x3, x4);
303 }
304 
305 /*******************************************************************************
306  * This function handles all SMCs in the range reserved for RMI. Each call is
307  * either forwarded to the other security state or handled by the RMM dispatcher
308  ******************************************************************************/
rmmd_rmi_handler(uint32_t smc_fid,uint64_t x1,uint64_t x2,uint64_t x3,uint64_t x4,void * cookie,void * handle,uint64_t flags)309 uint64_t rmmd_rmi_handler(uint32_t smc_fid, uint64_t x1, uint64_t x2,
310 			  uint64_t x3, uint64_t x4, void *cookie,
311 			  void *handle, uint64_t flags)
312 {
313 	uint32_t src_sec_state;
314 
315 	/* If RMM failed to boot, treat any RMI SMC as unknown */
316 	if (rmm_boot_failed) {
317 		WARN("RMMD: Failed to boot up RMM. Ignoring RMI call\n");
318 		SMC_RET1(handle, SMC_UNK);
319 	}
320 
321 	/* Determine which security state this SMC originated from */
322 	src_sec_state = caller_sec_state(flags);
323 
324 	/* RMI must not be invoked by the Secure world */
325 	if (src_sec_state == SMC_FROM_SECURE) {
326 		WARN("RMMD: RMI invoked by secure world.\n");
327 		SMC_RET1(handle, SMC_UNK);
328 	}
329 
330 	/*
331 	 * Forward an RMI call from the Normal world to the Realm world as it
332 	 * is.
333 	 */
334 	if (src_sec_state == SMC_FROM_NON_SECURE) {
335 		/*
336 		 * If SVE hint bit is set in the flags then update the SMC
337 		 * function id and pass it on to the lower EL.
338 		 */
339 		if (is_sve_hint_set(flags)) {
340 			smc_fid |= (FUNCID_SVE_HINT_MASK <<
341 				    FUNCID_SVE_HINT_SHIFT);
342 		}
343 		VERBOSE("RMMD: RMI call from non-secure world.\n");
344 		return rmmd_smc_forward(NON_SECURE, REALM, smc_fid,
345 					x1, x2, x3, x4, handle);
346 	}
347 
348 	if (src_sec_state != SMC_FROM_REALM) {
349 		SMC_RET1(handle, SMC_UNK);
350 	}
351 
352 	switch (smc_fid) {
353 	case RMM_RMI_REQ_COMPLETE: {
354 		uint64_t x5 = SMC_GET_GP(handle, CTX_GPREG_X5);
355 
356 		return rmmd_smc_forward(REALM, NON_SECURE, x1,
357 					x2, x3, x4, x5, handle);
358 	}
359 	default:
360 		WARN("RMMD: Unsupported RMM call 0x%08x\n", smc_fid);
361 		SMC_RET1(handle, SMC_UNK);
362 	}
363 }
364 
365 /*******************************************************************************
366  * This cpu has been turned on. Enter RMM to initialise R-EL2.  Entry into RMM
367  * is done after initialising minimal architectural state that guarantees safe
368  * execution.
369  ******************************************************************************/
rmmd_cpu_on_finish_handler(const void * arg)370 static void *rmmd_cpu_on_finish_handler(const void *arg)
371 {
372 	long rc;
373 	uint32_t linear_id = plat_my_core_pos();
374 	rmmd_rmm_context_t *ctx = &rmm_context[linear_id];
375 
376 	if (rmm_boot_failed) {
377 		/* RMM Boot failed on a previous CPU. Abort. */
378 		ERROR("RMM Failed to initialize. Ignoring for CPU%d\n",
379 								linear_id);
380 		return NULL;
381 	}
382 
383 	/*
384 	 * Prepare warmboot arguments for RMM:
385 	 * arg0: This CPUID.
386 	 * arg1 to arg3: Not used.
387 	 */
388 	rmm_ep_info->args.arg0 = linear_id;
389 	rmm_ep_info->args.arg1 = 0ULL;
390 	rmm_ep_info->args.arg2 = 0ULL;
391 	rmm_ep_info->args.arg3 = 0ULL;
392 
393 	/* Initialise RMM context with this entry point information */
394 	cm_setup_context(&ctx->cpu_ctx, rmm_ep_info);
395 
396 	/* Enable architecture extensions */
397 	manage_extensions_realm(&ctx->cpu_ctx);
398 
399 	/* Initialize RMM EL2 context. */
400 	rmm_el2_context_init(&ctx->cpu_ctx.el2_sysregs_ctx);
401 
402 	rc = rmmd_rmm_sync_entry(ctx);
403 
404 	if (rc != E_RMM_BOOT_SUCCESS) {
405 		ERROR("RMM init failed on CPU%d: %ld\n", linear_id, rc);
406 		/* Mark the boot as failed for any other booting CPU */
407 		rmm_boot_failed = true;
408 	}
409 
410 	return NULL;
411 }
412 
413 /* Subscribe to PSCI CPU on to initialize RMM on secondary */
414 SUBSCRIBE_TO_EVENT(psci_cpu_on_finish, rmmd_cpu_on_finish_handler);
415 
416 /* Convert GPT lib error to RMMD GTS error */
gpt_to_gts_error(int error,uint32_t smc_fid,uint64_t address)417 static int gpt_to_gts_error(int error, uint32_t smc_fid, uint64_t address)
418 {
419 	int ret;
420 
421 	if (error == 0) {
422 		return E_RMM_OK;
423 	}
424 
425 	if (error == -EINVAL) {
426 		ret = E_RMM_BAD_ADDR;
427 	} else {
428 		/* This is the only other error code we expect */
429 		assert(error == -EPERM);
430 		ret = E_RMM_BAD_PAS;
431 	}
432 
433 	ERROR("RMMD: PAS Transition failed. GPT ret = %d, PA: 0x%"PRIx64 ", FID = 0x%x\n",
434 				error, address, smc_fid);
435 	return ret;
436 }
437 
438 /*******************************************************************************
439  * This function handles RMM-EL3 interface SMCs
440  ******************************************************************************/
rmmd_rmm_el3_handler(uint32_t smc_fid,uint64_t x1,uint64_t x2,uint64_t x3,uint64_t x4,void * cookie,void * handle,uint64_t flags)441 uint64_t rmmd_rmm_el3_handler(uint32_t smc_fid, uint64_t x1, uint64_t x2,
442 				uint64_t x3, uint64_t x4, void *cookie,
443 				void *handle, uint64_t flags)
444 {
445 	uint32_t src_sec_state;
446 	int ret;
447 
448 	/* If RMM failed to boot, treat any RMM-EL3 interface SMC as unknown */
449 	if (rmm_boot_failed) {
450 		WARN("RMMD: Failed to boot up RMM. Ignoring RMM-EL3 call\n");
451 		SMC_RET1(handle, SMC_UNK);
452 	}
453 
454 	/* Determine which security state this SMC originated from */
455 	src_sec_state = caller_sec_state(flags);
456 
457 	if (src_sec_state != SMC_FROM_REALM) {
458 		WARN("RMMD: RMM-EL3 call originated from secure or normal world\n");
459 		SMC_RET1(handle, SMC_UNK);
460 	}
461 
462 	switch (smc_fid) {
463 	case RMM_GTSI_DELEGATE:
464 		ret = gpt_delegate_pas(x1, PAGE_SIZE_4KB, SMC_FROM_REALM);
465 		SMC_RET1(handle, gpt_to_gts_error(ret, smc_fid, x1));
466 	case RMM_GTSI_UNDELEGATE:
467 		ret = gpt_undelegate_pas(x1, PAGE_SIZE_4KB, SMC_FROM_REALM);
468 		SMC_RET1(handle, gpt_to_gts_error(ret, smc_fid, x1));
469 	case RMM_ATTEST_GET_PLAT_TOKEN:
470 		ret = rmmd_attest_get_platform_token(x1, &x2, x3);
471 		SMC_RET2(handle, ret, x2);
472 	case RMM_ATTEST_GET_REALM_KEY:
473 		ret = rmmd_attest_get_signing_key(x1, &x2, x3);
474 		SMC_RET2(handle, ret, x2);
475 
476 	case RMM_BOOT_COMPLETE:
477 		VERBOSE("RMMD: running rmmd_rmm_sync_exit\n");
478 		rmmd_rmm_sync_exit(x1);
479 
480 	default:
481 		WARN("RMMD: Unsupported RMM-EL3 call 0x%08x\n", smc_fid);
482 		SMC_RET1(handle, SMC_UNK);
483 	}
484 }
485