1 /*
2 * Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 /*******************************************************************************
8 * This is the Secure Payload Dispatcher (SPD). The dispatcher is meant to be a
9 * plug-in component to the Secure Monitor, registered as a runtime service. The
10 * SPD is expected to be a functional extension of the Secure Payload (SP) that
11 * executes in Secure EL1. The Secure Monitor will delegate all SMCs targeting
12 * the Trusted OS/Applications range to the dispatcher. The SPD will either
13 * handle the request locally or delegate it to the Secure Payload. It is also
14 * responsible for initialising and maintaining communication with the SP.
15 ******************************************************************************/
16 #include <assert.h>
17 #include <errno.h>
18 #include <stddef.h>
19
20 #include <arch_helpers.h>
21 #include <bl31/bl31.h>
22 #include <bl32/payloads/tlk.h>
23 #include <common/bl_common.h>
24 #include <common/debug.h>
25 #include <common/runtime_svc.h>
26 #include <lib/el3_runtime/context_mgmt.h>
27 #include <plat/common/platform.h>
28 #include <tools_share/uuid.h>
29
30 #include "tlkd_private.h"
31
32 extern const spd_pm_ops_t tlkd_pm_ops;
33
34 /*******************************************************************************
35 * Per-cpu Secure Payload state
36 ******************************************************************************/
37 tlk_context_t tlk_ctx;
38
39 /*******************************************************************************
40 * CPU number on which TLK booted up
41 ******************************************************************************/
42 static uint32_t boot_cpu;
43
44 /* TLK UID: RFC-4122 compliant UUID (version-5, sha-1) */
45 DEFINE_SVC_UUID2(tlk_uuid,
46 0xc9e911bd, 0xba2b, 0xee52, 0xb1, 0x72,
47 0x46, 0x1f, 0xba, 0x97, 0x7f, 0x63);
48
49 static int32_t tlkd_init(void);
50
51 /*******************************************************************************
52 * Secure Payload Dispatcher setup. The SPD finds out the SP entrypoint and type
53 * (aarch32/aarch64) if not already known and initialises the context for entry
54 * into the SP for its initialisation.
55 ******************************************************************************/
tlkd_setup(void)56 static int32_t tlkd_setup(void)
57 {
58 entry_point_info_t *tlk_ep_info;
59
60 /*
61 * Get information about the Secure Payload (BL32) image. Its
62 * absence is a critical failure.
63 */
64 tlk_ep_info = bl31_plat_get_next_image_ep_info(SECURE);
65 if (!tlk_ep_info) {
66 WARN("No SP provided. Booting device without SP"
67 " initialization. SMC`s destined for SP"
68 " will return SMC_UNK\n");
69 return 1;
70 }
71
72 /*
73 * If there's no valid entry point for SP, we return a non-zero value
74 * signalling failure initializing the service. We bail out without
75 * registering any handlers
76 */
77 if (!tlk_ep_info->pc)
78 return 1;
79
80 /*
81 * Inspect the SP image's SPSR and determine it's execution state
82 * i.e whether AArch32 or AArch64.
83 */
84 tlkd_init_tlk_ep_state(tlk_ep_info,
85 (tlk_ep_info->spsr >> MODE_RW_SHIFT) & MODE_RW_MASK,
86 tlk_ep_info->pc,
87 &tlk_ctx);
88
89 /*
90 * All TLK SPD initialization done. Now register our init function
91 * with BL31 for deferred invocation
92 */
93 bl31_register_bl32_init(&tlkd_init);
94
95 return 0;
96 }
97
98 /*******************************************************************************
99 * This function passes control to the Secure Payload image (BL32) for the first
100 * time on the primary cpu after a cold boot. It assumes that a valid secure
101 * context has already been created by tlkd_setup() which can be directly
102 * used. This function performs a synchronous entry into the Secure payload.
103 * The SP passes control back to this routine through a SMC.
104 ******************************************************************************/
tlkd_init(void)105 static int32_t tlkd_init(void)
106 {
107 entry_point_info_t *tlk_entry_point;
108
109 /*
110 * Get information about the Secure Payload (BL32) image. Its
111 * absence is a critical failure.
112 */
113 tlk_entry_point = bl31_plat_get_next_image_ep_info(SECURE);
114 assert(tlk_entry_point);
115
116 cm_init_my_context(tlk_entry_point);
117
118 /*
119 * TLK runs only on a single CPU. Store the value of the boot
120 * CPU for sanity checking later.
121 */
122 boot_cpu = plat_my_core_pos();
123
124 /*
125 * Arrange for an entry into the test secure payload.
126 */
127 return tlkd_synchronous_sp_entry(&tlk_ctx);
128 }
129
130 /*******************************************************************************
131 * This function is responsible for handling all SMCs in the Trusted OS/App
132 * range from the non-secure state as defined in the SMC Calling Convention
133 * Document. It is also responsible for communicating with the Secure payload
134 * to delegate work and return results back to the non-secure state. Lastly it
135 * will also return any information that the secure payload needs to do the
136 * work assigned to it.
137 ******************************************************************************/
tlkd_smc_handler(uint32_t smc_fid,u_register_t x1,u_register_t x2,u_register_t x3,u_register_t x4,void * cookie,void * handle,u_register_t flags)138 static uintptr_t tlkd_smc_handler(uint32_t smc_fid,
139 u_register_t x1,
140 u_register_t x2,
141 u_register_t x3,
142 u_register_t x4,
143 void *cookie,
144 void *handle,
145 u_register_t flags)
146 {
147 cpu_context_t *ns_cpu_context;
148 gp_regs_t *gp_regs;
149 uint32_t ns;
150 uint64_t par;
151
152 /* Passing a NULL context is a critical programming error */
153 assert(handle);
154
155 /* These SMCs are only supported by a single CPU */
156 if (boot_cpu != plat_my_core_pos())
157 SMC_RET1(handle, SMC_UNK);
158
159 /* Determine which security state this SMC originated from */
160 ns = is_caller_non_secure(flags);
161
162 switch (smc_fid) {
163
164 /*
165 * This function ID is used by SP to indicate that it was
166 * preempted by a non-secure world IRQ.
167 */
168 case TLK_PREEMPTED:
169
170 if (ns)
171 SMC_RET1(handle, SMC_UNK);
172
173 assert(handle == cm_get_context(SECURE));
174 cm_el1_sysregs_context_save(SECURE);
175
176 /* Get a reference to the non-secure context */
177 ns_cpu_context = cm_get_context(NON_SECURE);
178 assert(ns_cpu_context);
179
180 /*
181 * Restore non-secure state. There is no need to save the
182 * secure system register context since the SP was supposed
183 * to preserve it during S-EL1 interrupt handling.
184 */
185 cm_el1_sysregs_context_restore(NON_SECURE);
186 cm_set_next_eret_context(NON_SECURE);
187
188 SMC_RET1(ns_cpu_context, x1);
189
190 /*
191 * This is a request from the non-secure context to:
192 *
193 * a. register shared memory with the SP for storing it's
194 * activity logs.
195 * b. register shared memory with the SP for passing args
196 * required for maintaining sessions with the Trusted
197 * Applications.
198 * c. register shared persistent buffers for secure storage
199 * d. register NS DRAM ranges passed by Cboot
200 * e. register Root of Trust parameters from Cboot for Verified Boot
201 * f. open/close sessions
202 * g. issue commands to the Trusted Apps
203 * h. resume the preempted yielding SMC call.
204 */
205 case TLK_REGISTER_LOGBUF:
206 case TLK_REGISTER_REQBUF:
207 case TLK_SS_REGISTER_HANDLER:
208 case TLK_REGISTER_NS_DRAM_RANGES:
209 case TLK_SET_ROOT_OF_TRUST:
210 case TLK_OPEN_TA_SESSION:
211 case TLK_CLOSE_TA_SESSION:
212 case TLK_TA_LAUNCH_OP:
213 case TLK_TA_SEND_EVENT:
214 case TLK_RESUME_FID:
215
216 if (!ns)
217 SMC_RET1(handle, SMC_UNK);
218
219 /*
220 * This is a fresh request from the non-secure client.
221 * The parameters are in x1 and x2. Figure out which
222 * registers need to be preserved, save the non-secure
223 * state and send the request to the secure payload.
224 */
225 assert(handle == cm_get_context(NON_SECURE));
226
227 /*
228 * Check if we are already processing a yielding SMC
229 * call. Of all the supported fids, only the "resume"
230 * fid expects the flag to be set.
231 */
232 if (smc_fid == TLK_RESUME_FID) {
233 if (!get_yield_smc_active_flag(tlk_ctx.state))
234 SMC_RET1(handle, SMC_UNK);
235 } else {
236 if (get_yield_smc_active_flag(tlk_ctx.state))
237 SMC_RET1(handle, SMC_UNK);
238 }
239
240 cm_el1_sysregs_context_save(NON_SECURE);
241
242 /*
243 * Verify if there is a valid context to use.
244 */
245 assert(&tlk_ctx.cpu_ctx == cm_get_context(SECURE));
246
247 /*
248 * Mark the SP state as active.
249 */
250 set_yield_smc_active_flag(tlk_ctx.state);
251
252 /*
253 * We are done stashing the non-secure context. Ask the
254 * secure payload to do the work now.
255 */
256 cm_el1_sysregs_context_restore(SECURE);
257 cm_set_next_eret_context(SECURE);
258
259 /*
260 * TLK is a 32-bit Trusted OS and so expects the SMC
261 * arguments via r0-r7. TLK expects the monitor frame
262 * registers to be 64-bits long. Hence, we pass x0 in
263 * r0-r1, x1 in r2-r3, x3 in r4-r5 and x4 in r6-r7.
264 *
265 * As smc_fid is a uint32 value, r1 contains 0.
266 */
267 gp_regs = get_gpregs_ctx(&tlk_ctx.cpu_ctx);
268 write_ctx_reg(gp_regs, CTX_GPREG_X4, (uint32_t)x2);
269 write_ctx_reg(gp_regs, CTX_GPREG_X5, (uint32_t)(x2 >> 32));
270 write_ctx_reg(gp_regs, CTX_GPREG_X6, (uint32_t)x3);
271 write_ctx_reg(gp_regs, CTX_GPREG_X7, (uint32_t)(x3 >> 32));
272 SMC_RET4(&tlk_ctx.cpu_ctx, smc_fid, 0, (uint32_t)x1,
273 (uint32_t)(x1 >> 32));
274
275 /*
276 * Translate NS/EL1-S virtual addresses.
277 *
278 * x1 = virtual address
279 * x3 = type (NS/S)
280 *
281 * Returns PA:lo in r0, PA:hi in r1.
282 */
283 case TLK_VA_TRANSLATE:
284
285 /* Should be invoked only by secure world */
286 if (ns)
287 SMC_RET1(handle, SMC_UNK);
288
289 /* NS virtual addresses are 64-bit long */
290 if (x3 & TLK_TRANSLATE_NS_VADDR)
291 x1 = (uint32_t)x1 | (x2 << 32);
292
293 if (!x1)
294 SMC_RET1(handle, SMC_UNK);
295
296 /*
297 * TODO: Sanity check x1. This would require platform
298 * support.
299 */
300
301 /* virtual address and type: ns/s */
302 par = tlkd_va_translate(x1, x3);
303
304 /* return physical address in r0-r1 */
305 SMC_RET4(handle, (uint32_t)par, (uint32_t)(par >> 32), 0, 0);
306
307 /*
308 * This is a request from the SP to mark completion of
309 * a yielding function ID.
310 */
311 case TLK_REQUEST_DONE:
312 if (ns)
313 SMC_RET1(handle, SMC_UNK);
314
315 /*
316 * Mark the SP state as inactive.
317 */
318 clr_yield_smc_active_flag(tlk_ctx.state);
319
320 /* Get a reference to the non-secure context */
321 ns_cpu_context = cm_get_context(NON_SECURE);
322 assert(ns_cpu_context);
323
324 /*
325 * This is a request completion SMC and we must switch to
326 * the non-secure world to pass the result.
327 */
328 cm_el1_sysregs_context_save(SECURE);
329
330 /*
331 * We are done stashing the secure context. Switch to the
332 * non-secure context and return the result.
333 */
334 cm_el1_sysregs_context_restore(NON_SECURE);
335 cm_set_next_eret_context(NON_SECURE);
336 SMC_RET1(ns_cpu_context, x1);
337
338 /*
339 * This function ID is used only by the SP to indicate it has
340 * finished initialising itself after a cold boot
341 */
342 case TLK_ENTRY_DONE:
343 if (ns)
344 SMC_RET1(handle, SMC_UNK);
345
346 /*
347 * SP has been successfully initialized. Register power
348 * management hooks with PSCI
349 */
350 psci_register_spd_pm_hook(&tlkd_pm_ops);
351
352 /*
353 * TLK reports completion. The SPD must have initiated
354 * the original request through a synchronous entry
355 * into the SP. Jump back to the original C runtime
356 * context.
357 */
358 tlkd_synchronous_sp_exit(&tlk_ctx, x1);
359 break;
360
361 /*
362 * These function IDs are used only by TLK to indicate it has
363 * finished:
364 * 1. suspending itself after an earlier psci cpu_suspend
365 * request.
366 * 2. resuming itself after an earlier psci cpu_suspend
367 * request.
368 * 3. powering down after an earlier psci system_off/system_reset
369 * request.
370 */
371 case TLK_SUSPEND_DONE:
372 case TLK_RESUME_DONE:
373 case TLK_SYSTEM_OFF_DONE:
374
375 if (ns)
376 SMC_RET1(handle, SMC_UNK);
377
378 /*
379 * TLK reports completion. TLKD must have initiated the
380 * original request through a synchronous entry into the SP.
381 * Jump back to the original C runtime context, and pass x1 as
382 * return value to the caller
383 */
384 tlkd_synchronous_sp_exit(&tlk_ctx, x1);
385 break;
386
387 /*
388 * Return the number of service function IDs implemented to
389 * provide service to non-secure
390 */
391 case TOS_CALL_COUNT:
392 SMC_RET1(handle, TLK_NUM_FID);
393
394 /*
395 * Return TLK's UID to the caller
396 */
397 case TOS_UID:
398 SMC_UUID_RET(handle, tlk_uuid);
399
400 /*
401 * Return the version of current implementation
402 */
403 case TOS_CALL_VERSION:
404 SMC_RET2(handle, TLK_VERSION_MAJOR, TLK_VERSION_MINOR);
405
406 default:
407 WARN("%s: Unhandled SMC: 0x%x\n", __func__, smc_fid);
408 break;
409 }
410
411 SMC_RET1(handle, SMC_UNK);
412 }
413
414 /* Define a SPD runtime service descriptor for fast SMC calls */
415 DECLARE_RT_SVC(
416 tlkd_tos_fast,
417
418 OEN_TOS_START,
419 OEN_TOS_END,
420 SMC_TYPE_FAST,
421 tlkd_setup,
422 tlkd_smc_handler
423 );
424
425 /* Define a SPD runtime service descriptor for yielding SMC calls */
426 DECLARE_RT_SVC(
427 tlkd_tos_std,
428
429 OEN_TOS_START,
430 OEN_TOS_END,
431 SMC_TYPE_YIELD,
432 NULL,
433 tlkd_smc_handler
434 );
435
436 /* Define a SPD runtime service descriptor for fast SMC calls */
437 DECLARE_RT_SVC(
438 tlkd_tap_fast,
439
440 OEN_TAP_START,
441 OEN_TAP_END,
442 SMC_TYPE_FAST,
443 NULL,
444 tlkd_smc_handler
445 );
446
447 /* Define a SPD runtime service descriptor for yielding SMC calls */
448 DECLARE_RT_SVC(
449 tlkd_tap_std,
450
451 OEN_TAP_START,
452 OEN_TAP_END,
453 SMC_TYPE_YIELD,
454 NULL,
455 tlkd_smc_handler
456 );
457