Varun Wadekar | 2203831 | 2015-03-13 14:01:03 +0530 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved. |
| 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions are met: |
| 6 | * |
| 7 | * Redistributions of source code must retain the above copyright notice, this |
| 8 | * list of conditions and the following disclaimer. |
| 9 | * |
| 10 | * Redistributions in binary form must reproduce the above copyright notice, |
| 11 | * this list of conditions and the following disclaimer in the documentation |
| 12 | * and/or other materials provided with the distribution. |
| 13 | * |
| 14 | * Neither the name of ARM nor the names of its contributors may be used |
| 15 | * to endorse or promote products derived from this software without specific |
| 16 | * prior written permission. |
| 17 | * |
| 18 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| 19 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 20 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 21 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE |
| 22 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 23 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 24 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 25 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 26 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 27 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 28 | * POSSIBILITY OF SUCH DAMAGE. |
| 29 | */ |
| 30 | |
| 31 | /******************************************************************************* |
| 32 | * This is the Secure Payload Dispatcher (SPD). The dispatcher is meant to be a |
| 33 | * plug-in component to the Secure Monitor, registered as a runtime service. The |
| 34 | * SPD is expected to be a functional extension of the Secure Payload (SP) that |
| 35 | * executes in Secure EL1. The Secure Monitor will delegate all SMCs targeting |
| 36 | * the Trusted OS/Applications range to the dispatcher. The SPD will either |
| 37 | * handle the request locally or delegate it to the Secure Payload. It is also |
| 38 | * responsible for initialising and maintaining communication with the SP. |
| 39 | ******************************************************************************/ |
| 40 | #include <arch_helpers.h> |
| 41 | #include <assert.h> |
| 42 | #include <bl_common.h> |
| 43 | #include <bl31.h> |
| 44 | #include <context_mgmt.h> |
| 45 | #include <debug.h> |
| 46 | #include <errno.h> |
| 47 | #include <platform.h> |
| 48 | #include <runtime_svc.h> |
| 49 | #include <stddef.h> |
| 50 | #include <tlk.h> |
| 51 | #include <uuid.h> |
| 52 | #include "tlkd_private.h" |
| 53 | |
| 54 | extern const spd_pm_ops_t tlkd_pm_ops; |
| 55 | |
| 56 | /******************************************************************************* |
| 57 | * Array to keep track of per-cpu Secure Payload state |
| 58 | ******************************************************************************/ |
| 59 | static tlk_context_t tlk_ctx; |
| 60 | |
| 61 | /* TLK UID: RFC-4122 compliant UUID (version-5, sha-1) */ |
| 62 | DEFINE_SVC_UUID(tlk_uuid, |
| 63 | 0xbd11e9c9, 0x2bba, 0x52ee, 0xb1, 0x72, |
| 64 | 0x46, 0x1f, 0xba, 0x97, 0x7f, 0x63); |
| 65 | |
| 66 | int32_t tlkd_init(void); |
| 67 | |
| 68 | /* |
| 69 | * The number of arguments/results to save during a SMC call for TLK. |
| 70 | */ |
| 71 | #define TLK_SHDBUF_SIZE 4 |
| 72 | |
| 73 | /******************************************************************************* |
| 74 | * Shared memory buffer for passing SMC args/results to TLK |
| 75 | ******************************************************************************/ |
| 76 | typedef struct tlk_args_results { |
| 77 | uint64_t args[TLK_SHDBUF_SIZE]; |
| 78 | } tlk_args_results_t; |
| 79 | |
| 80 | static tlk_args_results_t *tlk_args_results_buf; |
| 81 | |
| 82 | /* |
| 83 | * Helper function to store args from TLK and pass results back |
| 84 | */ |
| 85 | static inline void store_tlk_args_results(uint64_t x0, uint64_t x1, uint64_t x2, |
| 86 | uint64_t x3) |
| 87 | { |
| 88 | /* store arguments sent by TLK */ |
| 89 | tlk_args_results_buf->args[0] = x0; |
| 90 | tlk_args_results_buf->args[1] = x1; |
| 91 | tlk_args_results_buf->args[2] = x2; |
| 92 | tlk_args_results_buf->args[3] = x3; |
| 93 | |
| 94 | flush_dcache_range((uint64_t)tlk_args_results_buf, |
| 95 | sizeof(tlk_args_results_t)); |
| 96 | } |
| 97 | |
| 98 | /******************************************************************************* |
| 99 | * Secure Payload Dispatcher setup. The SPD finds out the SP entrypoint and type |
| 100 | * (aarch32/aarch64) if not already known and initialises the context for entry |
| 101 | * into the SP for its initialisation. |
| 102 | ******************************************************************************/ |
| 103 | int32_t tlkd_setup(void) |
| 104 | { |
| 105 | entry_point_info_t *tlk_ep_info; |
| 106 | |
| 107 | /* |
| 108 | * Get information about the Secure Payload (BL32) image. Its |
| 109 | * absence is a critical failure. |
| 110 | */ |
| 111 | tlk_ep_info = bl31_plat_get_next_image_ep_info(SECURE); |
| 112 | if (!tlk_ep_info) { |
| 113 | WARN("No SP provided. Booting device without SP" |
| 114 | " initialization. SMC`s destined for SP" |
| 115 | " will return SMC_UNK\n"); |
| 116 | return 1; |
| 117 | } |
| 118 | |
| 119 | /* |
| 120 | * If there's no valid entry point for SP, we return a non-zero value |
| 121 | * signalling failure initializing the service. We bail out without |
| 122 | * registering any handlers |
| 123 | */ |
| 124 | if (!tlk_ep_info->pc) |
| 125 | return 1; |
| 126 | |
| 127 | /* |
| 128 | * Inspect the SP image's SPSR and determine it's execution state |
| 129 | * i.e whether AArch32 or AArch64. |
| 130 | */ |
| 131 | tlkd_init_tlk_ep_state(tlk_ep_info, |
| 132 | (tlk_ep_info->spsr >> MODE_RW_SHIFT) & MODE_RW_MASK, |
| 133 | tlk_ep_info->pc, |
| 134 | &tlk_ctx); |
| 135 | |
| 136 | /* |
| 137 | * All TLK SPD initialization done. Now register our init function |
| 138 | * with BL31 for deferred invocation |
| 139 | */ |
| 140 | bl31_register_bl32_init(&tlkd_init); |
| 141 | |
| 142 | return 0; |
| 143 | } |
| 144 | |
| 145 | /******************************************************************************* |
| 146 | * This function passes control to the Secure Payload image (BL32) for the first |
| 147 | * time on the primary cpu after a cold boot. It assumes that a valid secure |
| 148 | * context has already been created by tlkd_setup() which can be directly |
| 149 | * used. This function performs a synchronous entry into the Secure payload. |
| 150 | * The SP passes control back to this routine through a SMC. |
| 151 | ******************************************************************************/ |
| 152 | int32_t tlkd_init(void) |
| 153 | { |
| 154 | uint64_t mpidr = read_mpidr(); |
| 155 | entry_point_info_t *tlk_entry_point; |
| 156 | |
| 157 | /* |
| 158 | * Get information about the Secure Payload (BL32) image. Its |
| 159 | * absence is a critical failure. |
| 160 | */ |
| 161 | tlk_entry_point = bl31_plat_get_next_image_ep_info(SECURE); |
| 162 | assert(tlk_entry_point); |
| 163 | |
| 164 | cm_init_context(mpidr, tlk_entry_point); |
| 165 | |
| 166 | /* |
| 167 | * Arrange for an entry into the test secure payload. |
| 168 | */ |
| 169 | return tlkd_synchronous_sp_entry(&tlk_ctx); |
| 170 | } |
| 171 | |
| 172 | /******************************************************************************* |
| 173 | * This function is responsible for handling all SMCs in the Trusted OS/App |
| 174 | * range from the non-secure state as defined in the SMC Calling Convention |
| 175 | * Document. It is also responsible for communicating with the Secure payload |
| 176 | * to delegate work and return results back to the non-secure state. Lastly it |
| 177 | * will also return any information that the secure payload needs to do the |
| 178 | * work assigned to it. |
| 179 | ******************************************************************************/ |
| 180 | uint64_t tlkd_smc_handler(uint32_t smc_fid, |
| 181 | uint64_t x1, |
| 182 | uint64_t x2, |
| 183 | uint64_t x3, |
| 184 | uint64_t x4, |
| 185 | void *cookie, |
| 186 | void *handle, |
| 187 | uint64_t flags) |
| 188 | { |
Varun Wadekar | 77199df | 2015-03-13 14:19:11 +0530 | [diff] [blame^] | 189 | cpu_context_t *ns_cpu_context; |
Varun Wadekar | 2203831 | 2015-03-13 14:01:03 +0530 | [diff] [blame] | 190 | uint32_t ns; |
| 191 | |
| 192 | /* Passing a NULL context is a critical programming error */ |
| 193 | assert(handle); |
| 194 | |
| 195 | /* Determine which security state this SMC originated from */ |
| 196 | ns = is_caller_non_secure(flags); |
| 197 | |
| 198 | switch (smc_fid) { |
| 199 | |
| 200 | /* |
Varun Wadekar | 77199df | 2015-03-13 14:19:11 +0530 | [diff] [blame^] | 201 | * This is a request from the non-secure context to: |
| 202 | * |
| 203 | * a. register shared memory with the SP for storing it's |
| 204 | * activity logs. |
| 205 | * b. register shared memory with the SP for passing args |
| 206 | * required for maintaining sessions with the Trusted |
| 207 | * Applications. |
| 208 | */ |
| 209 | case TLK_REGISTER_LOGBUF: |
| 210 | case TLK_REGISTER_REQBUF: |
| 211 | if (!ns || !tlk_args_results_buf) |
| 212 | SMC_RET1(handle, SMC_UNK); |
| 213 | |
| 214 | /* |
| 215 | * This is a fresh request from the non-secure client. |
| 216 | * The parameters are in x1 and x2. Figure out which |
| 217 | * registers need to be preserved, save the non-secure |
| 218 | * state and send the request to the secure payload. |
| 219 | */ |
| 220 | assert(handle == cm_get_context(NON_SECURE)); |
| 221 | |
| 222 | /* Check if we are already preempted */ |
| 223 | if (get_std_smc_active_flag(tlk_ctx.state)) |
| 224 | SMC_RET1(handle, SMC_UNK); |
| 225 | |
| 226 | cm_el1_sysregs_context_save(NON_SECURE); |
| 227 | |
| 228 | /* |
| 229 | * Verify if there is a valid context to use. |
| 230 | */ |
| 231 | assert(&tlk_ctx.cpu_ctx == cm_get_context(SECURE)); |
| 232 | |
| 233 | /* |
| 234 | * Mark the SP state as active. |
| 235 | */ |
| 236 | set_std_smc_active_flag(tlk_ctx.state); |
| 237 | |
| 238 | /* Save args for use by the SP on return */ |
| 239 | store_tlk_args_results(smc_fid, x1, x2, x3); |
| 240 | |
| 241 | /* |
| 242 | * We are done stashing the non-secure context. Ask the |
| 243 | * secure payload to do the work now. |
| 244 | */ |
| 245 | cm_el1_sysregs_context_restore(SECURE); |
| 246 | cm_set_next_eret_context(SECURE); |
| 247 | SMC_RET0(&tlk_ctx.cpu_ctx); |
| 248 | |
| 249 | /* |
| 250 | * This is a request from the SP to mark completion of |
| 251 | * a standard function ID. |
| 252 | */ |
| 253 | case TLK_REQUEST_DONE: |
| 254 | if (ns || !tlk_args_results_buf) |
| 255 | SMC_RET1(handle, SMC_UNK); |
| 256 | |
| 257 | /* |
| 258 | * Mark the SP state as inactive. |
| 259 | */ |
| 260 | clr_std_smc_active_flag(tlk_ctx.state); |
| 261 | |
| 262 | /* Get a reference to the non-secure context */ |
| 263 | ns_cpu_context = cm_get_context(NON_SECURE); |
| 264 | assert(ns_cpu_context); |
| 265 | |
| 266 | /* |
| 267 | * This is a request completion SMC and we must switch to |
| 268 | * the non-secure world to pass the result. |
| 269 | */ |
| 270 | cm_el1_sysregs_context_save(SECURE); |
| 271 | |
| 272 | /* |
| 273 | * We are done stashing the secure context. Switch to the |
| 274 | * non-secure context and return the result. |
| 275 | */ |
| 276 | cm_el1_sysregs_context_restore(NON_SECURE); |
| 277 | cm_set_next_eret_context(NON_SECURE); |
| 278 | SMC_RET1(ns_cpu_context, tlk_args_results_buf->args[0]); |
| 279 | |
| 280 | /* |
Varun Wadekar | 2203831 | 2015-03-13 14:01:03 +0530 | [diff] [blame] | 281 | * This function ID is used only by the SP to indicate it has |
| 282 | * finished initialising itself after a cold boot |
| 283 | */ |
| 284 | case TLK_ENTRY_DONE: |
Varun Wadekar | 77199df | 2015-03-13 14:19:11 +0530 | [diff] [blame^] | 285 | if (ns || !tlk_args_results_buf) |
Varun Wadekar | 2203831 | 2015-03-13 14:01:03 +0530 | [diff] [blame] | 286 | SMC_RET1(handle, SMC_UNK); |
| 287 | |
| 288 | /* |
| 289 | * SP has been successfully initialized. Register power |
| 290 | * managemnt hooks with PSCI |
| 291 | */ |
| 292 | psci_register_spd_pm_hook(&tlkd_pm_ops); |
| 293 | |
| 294 | /* |
| 295 | * TLK reports completion. The SPD must have initiated |
| 296 | * the original request through a synchronous entry |
| 297 | * into the SP. Jump back to the original C runtime |
| 298 | * context. |
| 299 | */ |
| 300 | tlkd_synchronous_sp_exit(&tlk_ctx, tlk_args_results_buf->args[0]); |
| 301 | |
| 302 | /* |
| 303 | * This is a request from the secure payload to register |
| 304 | * shared memory to pass SMC args/results between EL1, EL3. |
| 305 | */ |
| 306 | case TLK_FID_SHARED_MEMBUF: |
| 307 | if (ns || !x1) |
| 308 | SMC_RET1(handle, SMC_UNK); |
| 309 | |
| 310 | /* |
| 311 | * TODO: Check if the passed memory pointer is valid. Might |
| 312 | * require a call into the platform code. |
| 313 | */ |
| 314 | |
| 315 | tlk_args_results_buf = (tlk_args_results_t *)x1; |
| 316 | SMC_RET0(handle); |
| 317 | |
| 318 | /* |
| 319 | * Return the number of service function IDs implemented to |
| 320 | * provide service to non-secure |
| 321 | */ |
| 322 | case TOS_CALL_COUNT: |
| 323 | SMC_RET1(handle, TLK_NUM_FID); |
| 324 | |
| 325 | /* |
| 326 | * Return TLK's UID to the caller |
| 327 | */ |
| 328 | case TOS_UID: |
| 329 | SMC_UUID_RET(handle, tlk_uuid); |
| 330 | |
| 331 | /* |
| 332 | * Return the version of current implementation |
| 333 | */ |
| 334 | case TOS_CALL_VERSION: |
| 335 | SMC_RET2(handle, TLK_VERSION_MAJOR, TLK_VERSION_MINOR); |
| 336 | |
| 337 | default: |
| 338 | break; |
| 339 | } |
| 340 | |
| 341 | SMC_RET1(handle, SMC_UNK); |
| 342 | } |
| 343 | |
| 344 | /* Define a SPD runtime service descriptor for fast SMC calls */ |
| 345 | DECLARE_RT_SVC( |
| 346 | tlkd_tos_fast, |
| 347 | |
| 348 | OEN_TOS_START, |
| 349 | OEN_TOS_END, |
| 350 | SMC_TYPE_FAST, |
| 351 | tlkd_setup, |
| 352 | tlkd_smc_handler |
| 353 | ); |
| 354 | |
| 355 | /* Define a SPD runtime service descriptor for standard SMC calls */ |
| 356 | DECLARE_RT_SVC( |
| 357 | tlkd_tos_std, |
| 358 | |
| 359 | OEN_TOS_START, |
| 360 | OEN_TOS_END, |
| 361 | SMC_TYPE_STD, |
| 362 | NULL, |
| 363 | tlkd_smc_handler |
| 364 | ); |