1 /*
2 * Copyright (c) 2015-2017, 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 <arch_helpers.h>
17 #include <assert.h>
18 #include <bl31.h>
19 #include <bl_common.h>
20 #include <context_mgmt.h>
21 #include <debug.h>
22 #include <errno.h>
23 #include <platform.h>
24 #include <runtime_svc.h>
25 #include <stddef.h>
26 #include <tlk.h>
27 #include <uuid.h>
28 #include "tlkd_private.h"
29
30 extern const spd_pm_ops_t tlkd_pm_ops;
31
32 /*******************************************************************************
33 * Per-cpu Secure Payload state
34 ******************************************************************************/
35 tlk_context_t tlk_ctx;
36
37 /*******************************************************************************
38 * CPU number on which TLK booted up
39 ******************************************************************************/
40 static uint32_t boot_cpu;
41
42 /* TLK UID: RFC-4122 compliant UUID (version-5, sha-1) */
43 DEFINE_SVC_UUID(tlk_uuid,
44 0xbd11e9c9, 0x2bba, 0x52ee, 0xb1, 0x72,
45 0x46, 0x1f, 0xba, 0x97, 0x7f, 0x63);
46
47 int32_t tlkd_init(void);
48
49 /*******************************************************************************
50 * Secure Payload Dispatcher setup. The SPD finds out the SP entrypoint and type
51 * (aarch32/aarch64) if not already known and initialises the context for entry
52 * into the SP for its initialisation.
53 ******************************************************************************/
tlkd_setup(void)54 int32_t tlkd_setup(void)
55 {
56 entry_point_info_t *tlk_ep_info;
57
58 /*
59 * Get information about the Secure Payload (BL32) image. Its
60 * absence is a critical failure.
61 */
62 tlk_ep_info = bl31_plat_get_next_image_ep_info(SECURE);
63 if (!tlk_ep_info) {
64 WARN("No SP provided. Booting device without SP"
65 " initialization. SMC`s destined for SP"
66 " will return SMC_UNK\n");
67 return 1;
68 }
69
70 /*
71 * If there's no valid entry point for SP, we return a non-zero value
72 * signalling failure initializing the service. We bail out without
73 * registering any handlers
74 */
75 if (!tlk_ep_info->pc)
76 return 1;
77
78 /*
79 * Inspect the SP image's SPSR and determine it's execution state
80 * i.e whether AArch32 or AArch64.
81 */
82 tlkd_init_tlk_ep_state(tlk_ep_info,
83 (tlk_ep_info->spsr >> MODE_RW_SHIFT) & MODE_RW_MASK,
84 tlk_ep_info->pc,
85 &tlk_ctx);
86
87 /*
88 * All TLK SPD initialization done. Now register our init function
89 * with BL31 for deferred invocation
90 */
91 bl31_register_bl32_init(&tlkd_init);
92
93 return 0;
94 }
95
96 /*******************************************************************************
97 * This function passes control to the Secure Payload image (BL32) for the first
98 * time on the primary cpu after a cold boot. It assumes that a valid secure
99 * context has already been created by tlkd_setup() which can be directly
100 * used. This function performs a synchronous entry into the Secure payload.
101 * The SP passes control back to this routine through a SMC.
102 ******************************************************************************/
tlkd_init(void)103 int32_t tlkd_init(void)
104 {
105 entry_point_info_t *tlk_entry_point;
106
107 /*
108 * Get information about the Secure Payload (BL32) image. Its
109 * absence is a critical failure.
110 */
111 tlk_entry_point = bl31_plat_get_next_image_ep_info(SECURE);
112 assert(tlk_entry_point);
113
114 cm_init_my_context(tlk_entry_point);
115
116 /*
117 * TLK runs only on a single CPU. Store the value of the boot
118 * CPU for sanity checking later.
119 */
120 boot_cpu = plat_my_core_pos();
121
122 /*
123 * Arrange for an entry into the test secure payload.
124 */
125 return tlkd_synchronous_sp_entry(&tlk_ctx);
126 }
127
128 /*******************************************************************************
129 * This function is responsible for handling all SMCs in the Trusted OS/App
130 * range from the non-secure state as defined in the SMC Calling Convention
131 * Document. It is also responsible for communicating with the Secure payload
132 * to delegate work and return results back to the non-secure state. Lastly it
133 * will also return any information that the secure payload needs to do the
134 * work assigned to it.
135 ******************************************************************************/
tlkd_smc_handler(uint32_t smc_fid,uint64_t x1,uint64_t x2,uint64_t x3,uint64_t x4,void * cookie,void * handle,uint64_t flags)136 uint64_t tlkd_smc_handler(uint32_t smc_fid,
137 uint64_t x1,
138 uint64_t x2,
139 uint64_t x3,
140 uint64_t x4,
141 void *cookie,
142 void *handle,
143 uint64_t flags)
144 {
145 cpu_context_t *ns_cpu_context;
146 gp_regs_t *gp_regs;
147 uint32_t ns;
148 uint64_t par;
149
150 /* Passing a NULL context is a critical programming error */
151 assert(handle);
152
153 /* These SMCs are only supported by a single CPU */
154 if (boot_cpu != plat_my_core_pos())
155 SMC_RET1(handle, SMC_UNK);
156
157 /* Determine which security state this SMC originated from */
158 ns = is_caller_non_secure(flags);
159
160 switch (smc_fid) {
161
162 /*
163 * This function ID is used by SP to indicate that it was
164 * preempted by a non-secure world IRQ.
165 */
166 case TLK_PREEMPTED:
167
168 if (ns)
169 SMC_RET1(handle, SMC_UNK);
170
171 assert(handle == cm_get_context(SECURE));
172 cm_el1_sysregs_context_save(SECURE);
173
174 /* Get a reference to the non-secure context */
175 ns_cpu_context = cm_get_context(NON_SECURE);
176 assert(ns_cpu_context);
177
178 /*
179 * Restore non-secure state. There is no need to save the
180 * secure system register context since the SP was supposed
181 * to preserve it during S-EL1 interrupt handling.
182 */
183 cm_el1_sysregs_context_restore(NON_SECURE);
184 cm_set_next_eret_context(NON_SECURE);
185
186 SMC_RET1(ns_cpu_context, x1);
187
188 /*
189 * This is a request from the non-secure context to:
190 *
191 * a. register shared memory with the SP for storing it's
192 * activity logs.
193 * b. register shared memory with the SP for passing args
194 * required for maintaining sessions with the Trusted
195 * Applications.
196 * c. open/close sessions
197 * d. issue commands to the Trusted Apps
198 * e. resume the preempted yielding SMC call.
199 */
200 case TLK_REGISTER_LOGBUF:
201 case TLK_REGISTER_REQBUF:
202 case TLK_OPEN_TA_SESSION:
203 case TLK_CLOSE_TA_SESSION:
204 case TLK_TA_LAUNCH_OP:
205 case TLK_TA_SEND_EVENT:
206 case TLK_RESUME_FID:
207
208 if (!ns)
209 SMC_RET1(handle, SMC_UNK);
210
211 /*
212 * This is a fresh request from the non-secure client.
213 * The parameters are in x1 and x2. Figure out which
214 * registers need to be preserved, save the non-secure
215 * state and send the request to the secure payload.
216 */
217 assert(handle == cm_get_context(NON_SECURE));
218
219 /*
220 * Check if we are already processing a yielding SMC
221 * call. Of all the supported fids, only the "resume"
222 * fid expects the flag to be set.
223 */
224 if (smc_fid == TLK_RESUME_FID) {
225 if (!get_yield_smc_active_flag(tlk_ctx.state))
226 SMC_RET1(handle, SMC_UNK);
227 } else {
228 if (get_yield_smc_active_flag(tlk_ctx.state))
229 SMC_RET1(handle, SMC_UNK);
230 }
231
232 cm_el1_sysregs_context_save(NON_SECURE);
233
234 /*
235 * Verify if there is a valid context to use.
236 */
237 assert(&tlk_ctx.cpu_ctx == cm_get_context(SECURE));
238
239 /*
240 * Mark the SP state as active.
241 */
242 set_yield_smc_active_flag(tlk_ctx.state);
243
244 /*
245 * We are done stashing the non-secure context. Ask the
246 * secure payload to do the work now.
247 */
248 cm_el1_sysregs_context_restore(SECURE);
249 cm_set_next_eret_context(SECURE);
250
251 /*
252 * TLK is a 32-bit Trusted OS and so expects the SMC
253 * arguments via r0-r7. TLK expects the monitor frame
254 * registers to be 64-bits long. Hence, we pass x0 in
255 * r0-r1, x1 in r2-r3, x3 in r4-r5 and x4 in r6-r7.
256 *
257 * As smc_fid is a uint32 value, r1 contains 0.
258 */
259 gp_regs = get_gpregs_ctx(&tlk_ctx.cpu_ctx);
260 write_ctx_reg(gp_regs, CTX_GPREG_X4, (uint32_t)x2);
261 write_ctx_reg(gp_regs, CTX_GPREG_X5, (uint32_t)(x2 >> 32));
262 write_ctx_reg(gp_regs, CTX_GPREG_X6, (uint32_t)x3);
263 write_ctx_reg(gp_regs, CTX_GPREG_X7, (uint32_t)(x3 >> 32));
264 SMC_RET4(&tlk_ctx.cpu_ctx, smc_fid, 0, (uint32_t)x1,
265 (uint32_t)(x1 >> 32));
266
267 /*
268 * Translate NS/EL1-S virtual addresses.
269 *
270 * x1 = virtual address
271 * x3 = type (NS/S)
272 *
273 * Returns PA:lo in r0, PA:hi in r1.
274 */
275 case TLK_VA_TRANSLATE:
276
277 /* Should be invoked only by secure world */
278 if (ns)
279 SMC_RET1(handle, SMC_UNK);
280
281 /* NS virtual addresses are 64-bit long */
282 if (x3 & TLK_TRANSLATE_NS_VADDR)
283 x1 = (uint32_t)x1 | (x2 << 32);
284
285 if (!x1)
286 SMC_RET1(handle, SMC_UNK);
287
288 /*
289 * TODO: Sanity check x1. This would require platform
290 * support.
291 */
292
293 /* virtual address and type: ns/s */
294 par = tlkd_va_translate(x1, x3);
295
296 /* return physical address in r0-r1 */
297 SMC_RET4(handle, (uint32_t)par, (uint32_t)(par >> 32), 0, 0);
298
299 /*
300 * This is a request from the SP to mark completion of
301 * a yielding function ID.
302 */
303 case TLK_REQUEST_DONE:
304 if (ns)
305 SMC_RET1(handle, SMC_UNK);
306
307 /*
308 * Mark the SP state as inactive.
309 */
310 clr_yield_smc_active_flag(tlk_ctx.state);
311
312 /* Get a reference to the non-secure context */
313 ns_cpu_context = cm_get_context(NON_SECURE);
314 assert(ns_cpu_context);
315
316 /*
317 * This is a request completion SMC and we must switch to
318 * the non-secure world to pass the result.
319 */
320 cm_el1_sysregs_context_save(SECURE);
321
322 /*
323 * We are done stashing the secure context. Switch to the
324 * non-secure context and return the result.
325 */
326 cm_el1_sysregs_context_restore(NON_SECURE);
327 cm_set_next_eret_context(NON_SECURE);
328 SMC_RET1(ns_cpu_context, x1);
329
330 /*
331 * This function ID is used only by the SP to indicate it has
332 * finished initialising itself after a cold boot
333 */
334 case TLK_ENTRY_DONE:
335 if (ns)
336 SMC_RET1(handle, SMC_UNK);
337
338 /*
339 * SP has been successfully initialized. Register power
340 * managemnt hooks with PSCI
341 */
342 psci_register_spd_pm_hook(&tlkd_pm_ops);
343
344 /*
345 * TLK reports completion. The SPD must have initiated
346 * the original request through a synchronous entry
347 * into the SP. Jump back to the original C runtime
348 * context.
349 */
350 tlkd_synchronous_sp_exit(&tlk_ctx, x1);
351
352 /*
353 * These function IDs are used only by TLK to indicate it has
354 * finished:
355 * 1. suspending itself after an earlier psci cpu_suspend
356 * request.
357 * 2. resuming itself after an earlier psci cpu_suspend
358 * request.
359 * 3. powering down after an earlier psci system_off/system_reset
360 * request.
361 */
362 case TLK_SUSPEND_DONE:
363 case TLK_RESUME_DONE:
364 case TLK_SYSTEM_OFF_DONE:
365
366 if (ns)
367 SMC_RET1(handle, SMC_UNK);
368
369 /*
370 * TLK reports completion. TLKD must have initiated the
371 * original request through a synchronous entry into the SP.
372 * Jump back to the original C runtime context, and pass x1 as
373 * return value to the caller
374 */
375 tlkd_synchronous_sp_exit(&tlk_ctx, x1);
376
377 /*
378 * Return the number of service function IDs implemented to
379 * provide service to non-secure
380 */
381 case TOS_CALL_COUNT:
382 SMC_RET1(handle, TLK_NUM_FID);
383
384 /*
385 * Return TLK's UID to the caller
386 */
387 case TOS_UID:
388 SMC_UUID_RET(handle, tlk_uuid);
389
390 /*
391 * Return the version of current implementation
392 */
393 case TOS_CALL_VERSION:
394 SMC_RET2(handle, TLK_VERSION_MAJOR, TLK_VERSION_MINOR);
395
396 default:
397 break;
398 }
399
400 SMC_RET1(handle, SMC_UNK);
401 }
402
403 /* Define a SPD runtime service descriptor for fast SMC calls */
404 DECLARE_RT_SVC(
405 tlkd_tos_fast,
406
407 OEN_TOS_START,
408 OEN_TOS_END,
409 SMC_TYPE_FAST,
410 tlkd_setup,
411 tlkd_smc_handler
412 );
413
414 /* Define a SPD runtime service descriptor for yielding SMC calls */
415 DECLARE_RT_SVC(
416 tlkd_tos_std,
417
418 OEN_TOS_START,
419 OEN_TOS_END,
420 SMC_TYPE_YIELD,
421 NULL,
422 tlkd_smc_handler
423 );
424
425 /* Define a SPD runtime service descriptor for fast SMC calls */
426 DECLARE_RT_SVC(
427 tlkd_tap_fast,
428
429 OEN_TAP_START,
430 OEN_TAP_END,
431 SMC_TYPE_FAST,
432 NULL,
433 tlkd_smc_handler
434 );
435
436 /* Define a SPD runtime service descriptor for yielding SMC calls */
437 DECLARE_RT_SVC(
438 tlkd_tap_std,
439
440 OEN_TAP_START,
441 OEN_TAP_END,
442 SMC_TYPE_YIELD,
443 NULL,
444 tlkd_smc_handler
445 );
446