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001 /* Copyright (C) 2004,2005 David Decotigny 001 /* Copyright (C) 2004,2005 David Decotigny 002 002 003 This program is free software; you can redi 003 This program is free software; you can redistribute it and/or 004 modify it under the terms of the GNU Genera 004 modify it under the terms of the GNU General Public License 005 as published by the Free Software Foundatio 005 as published by the Free Software Foundation; either version 2 006 of the License, or (at your option) any lat 006 of the License, or (at your option) any later version. 007 007 008 This program is distributed in the hope tha 008 This program is distributed in the hope that it will be useful, 009 but WITHOUT ANY WARRANTY; without even the 009 but WITHOUT ANY WARRANTY; without even the implied warranty of 010 MERCHANTABILITY or FITNESS FOR A PARTICULAR 010 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 011 GNU General Public License for more details 011 GNU General Public License for more details. 012 012 013 You should have received a copy of the GNU 013 You should have received a copy of the GNU General Public License 014 along with this program; if not, write to t 014 along with this program; if not, write to the Free Software 015 Foundation, Inc., 59 Temple Place - Suite 3 015 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 016 USA. 016 USA. 017 */ 017 */ 018 018 019 #include <sos/physmem.h> 019 #include <sos/physmem.h> 020 #include <sos/kmem_slab.h> 020 #include <sos/kmem_slab.h> 021 #include <sos/kmalloc.h> 021 #include <sos/kmalloc.h> 022 #include <sos/klibc.h> 022 #include <sos/klibc.h> 023 #include <sos/list.h> 023 #include <sos/list.h> 024 #include <sos/assert.h> 024 #include <sos/assert.h> >> 025 #include <hwcore/mm_context.h> >> 026 #include <sos/process.h> >> 027 >> 028 #include <drivers/bochs.h> >> 029 #include <drivers/x86_videomem.h> 025 030 026 #include <hwcore/irq.h> 031 #include <hwcore/irq.h> 027 032 028 #include "thread.h" 033 #include "thread.h" 029 034 030 035 031 /** 036 /** 032 * The size of the stack of a kernel thread 037 * The size of the stack of a kernel thread 033 */ 038 */ 034 #define SOS_THREAD_KERNEL_STACK_SIZE (1*SOS_PA 039 #define SOS_THREAD_KERNEL_STACK_SIZE (1*SOS_PAGE_SIZE) 035 040 036 041 037 /** 042 /** 038 * The identifier of the thread currently runn 043 * The identifier of the thread currently running on CPU. 039 * 044 * 040 * We only support a SINGLE processor, ie a SI 045 * We only support a SINGLE processor, ie a SINGLE thread 041 * running at any time in the system. This gre 046 * running at any time in the system. This greatly simplifies the 042 * implementation of the system, since we don' 047 * implementation of the system, since we don't have to complicate 043 * things in order to retrieve the identifier 048 * things in order to retrieve the identifier of the threads running 044 * on the CPU. On multiprocessor systems the c 049 * on the CPU. On multiprocessor systems the current_thread below is 045 * an array indexed by the id of the CPU, so t 050 * an array indexed by the id of the CPU, so that the challenge is to 046 * retrieve the identifier of the CPU. This is 051 * retrieve the identifier of the CPU. This is usually done based on 047 * the stack address (Linux implementation) or 052 * the stack address (Linux implementation) or on some form of TLS 048 * ("Thread Local Storage": can be implemented 053 * ("Thread Local Storage": can be implemented by way of LDTs for the 049 * processes, accessed through the fs or gs re 054 * processes, accessed through the fs or gs registers). 050 */ 055 */ 051 static volatile struct sos_thread *current_thr 056 static volatile struct sos_thread *current_thread = NULL; 052 057 053 058 054 /* 059 /* 055 * The list of threads currently in the system 060 * The list of threads currently in the system. 056 * 061 * 057 * @note We could have used current_thread for 062 * @note We could have used current_thread for that... 058 */ 063 */ 059 static struct sos_thread *thread_list = NULL; 064 static struct sos_thread *thread_list = NULL; 060 065 061 066 062 /** 067 /** 063 * The Cache of thread structures 068 * The Cache of thread structures 064 */ 069 */ 065 static struct sos_kslab_cache *cache_thread; 070 static struct sos_kslab_cache *cache_thread; 066 071 067 072 >> 073 /** >> 074 * (Forwad declaration) Helper function to change the MMU config of >> 075 * the current executing thread. Analogous to function >> 076 * sos_thread_change_current_mm_context() of article 7 >> 077 */ >> 078 static sos_ret_t change_current_mm_context(struct sos_mm_context *mm_ctxt); >> 079 >> 080 068 struct sos_thread *sos_thread_get_current() 081 struct sos_thread *sos_thread_get_current() 069 { 082 { 070 SOS_ASSERT_FATAL(current_thread->state == SO 083 SOS_ASSERT_FATAL(current_thread->state == SOS_THR_RUNNING); 071 return (struct sos_thread*)current_thread; 084 return (struct sos_thread*)current_thread; 072 } 085 } 073 086 074 087 075 inline static sos_ret_t _set_current(struct so 088 inline static sos_ret_t _set_current(struct sos_thread *thr) 076 { 089 { 077 SOS_ASSERT_FATAL(thr->state == SOS_THR_READY 090 SOS_ASSERT_FATAL(thr->state == SOS_THR_READY); 078 current_thread = thr; 091 current_thread = thr; 079 current_thread->state = SOS_THR_RUNNING; 092 current_thread->state = SOS_THR_RUNNING; 080 return SOS_OK; 093 return SOS_OK; 081 } 094 } 082 095 083 096 084 sos_ret_t sos_thread_subsystem_setup(sos_vaddr 097 sos_ret_t sos_thread_subsystem_setup(sos_vaddr_t init_thread_stack_base_addr, 085 sos_size_ 098 sos_size_t init_thread_stack_size) 086 { 099 { 087 struct sos_thread *myself; 100 struct sos_thread *myself; 088 101 089 /* Allocate the cache of threads */ 102 /* Allocate the cache of threads */ 090 cache_thread = sos_kmem_cache_create("thread 103 cache_thread = sos_kmem_cache_create("thread", 091 sizeof( 104 sizeof(struct sos_thread), 092 2, 105 2, 093 0, 106 0, 094 SOS_KSL 107 SOS_KSLAB_CREATE_MAP 095 | SOS_K 108 | SOS_KSLAB_CREATE_ZERO); 096 if (! cache_thread) 109 if (! cache_thread) 097 return -SOS_ENOMEM; 110 return -SOS_ENOMEM; 098 111 099 /* Allocate a new thread structure for the c 112 /* Allocate a new thread structure for the current running thread */ 100 myself = (struct sos_thread*) sos_kmem_cache 113 myself = (struct sos_thread*) sos_kmem_cache_alloc(cache_thread, 101 114 SOS_KSLAB_ALLOC_ATOMIC); 102 if (! myself) 115 if (! myself) 103 return -SOS_ENOMEM; 116 return -SOS_ENOMEM; 104 117 105 /* Initialize the thread attributes */ 118 /* Initialize the thread attributes */ 106 strzcpy(myself->name, "[kinit]", SOS_THR_MAX 119 strzcpy(myself->name, "[kinit]", SOS_THR_MAX_NAMELEN); 107 myself->state = SOS_THR_CREATED; 120 myself->state = SOS_THR_CREATED; >> 121 myself->priority = SOS_SCHED_PRIO_LOWEST; 108 myself->kernel_stack_base_addr = init_thread 122 myself->kernel_stack_base_addr = init_thread_stack_base_addr; 109 myself->kernel_stack_size = init_thread 123 myself->kernel_stack_size = init_thread_stack_size; 110 124 111 /* Do some stack poisoning on the bottom of 125 /* Do some stack poisoning on the bottom of the stack, if needed */ 112 sos_cpu_state_prepare_detect_kernel_stack_ov 126 sos_cpu_state_prepare_detect_kernel_stack_overflow(myself->cpu_state, 113 127 myself->kernel_stack_base_addr, 114 128 myself->kernel_stack_size); 115 129 116 /* Add the thread in the global list */ 130 /* Add the thread in the global list */ 117 list_singleton_named(thread_list, myself, gb 131 list_singleton_named(thread_list, myself, gbl_prev, gbl_next); 118 132 119 /* Ok, now pretend that the running thread i 133 /* Ok, now pretend that the running thread is ourselves */ 120 myself->state = SOS_THR_READY; 134 myself->state = SOS_THR_READY; 121 _set_current(myself); 135 _set_current(myself); 122 136 123 return SOS_OK; 137 return SOS_OK; 124 } 138 } 125 139 126 140 127 struct sos_thread * 141 struct sos_thread * 128 sos_create_kernel_thread(const char *name, 142 sos_create_kernel_thread(const char *name, 129 sos_kernel_thread_sta 143 sos_kernel_thread_start_routine_t start_func, 130 void *start_arg) !! 144 void *start_arg, >> 145 sos_sched_priority_t priority) 131 { 146 { 132 __label__ undo_creation; 147 __label__ undo_creation; 133 sos_ui32_t flags; 148 sos_ui32_t flags; 134 struct sos_thread *new_thread; 149 struct sos_thread *new_thread; 135 150 136 if (! start_func) 151 if (! start_func) 137 return NULL; 152 return NULL; >> 153 if (! SOS_SCHED_PRIO_IS_VALID(priority)) >> 154 return NULL; 138 155 139 /* Allocate a new thread structure for the c 156 /* Allocate a new thread structure for the current running thread */ 140 new_thread 157 new_thread 141 = (struct sos_thread*) sos_kmem_cache_allo 158 = (struct sos_thread*) sos_kmem_cache_alloc(cache_thread, 142 159 SOS_KSLAB_ALLOC_ATOMIC); 143 if (! new_thread) 160 if (! new_thread) 144 return NULL; 161 return NULL; 145 162 146 /* Initialize the thread attributes */ 163 /* Initialize the thread attributes */ 147 strzcpy(new_thread->name, ((name)?name:"[NON 164 strzcpy(new_thread->name, ((name)?name:"[NONAME]"), SOS_THR_MAX_NAMELEN); 148 new_thread->state = SOS_THR_CREATED; 165 new_thread->state = SOS_THR_CREATED; >> 166 new_thread->priority = priority; 149 167 150 /* Allocate the stack for the new thread */ 168 /* Allocate the stack for the new thread */ 151 new_thread->kernel_stack_base_addr = sos_kma 169 new_thread->kernel_stack_base_addr = sos_kmalloc(SOS_THREAD_KERNEL_STACK_SIZE, 0); 152 new_thread->kernel_stack_size = SOS_THR 170 new_thread->kernel_stack_size = SOS_THREAD_KERNEL_STACK_SIZE; 153 if (! new_thread->kernel_stack_base_addr) 171 if (! new_thread->kernel_stack_base_addr) 154 goto undo_creation; 172 goto undo_creation; 155 173 156 /* Initialize the CPU context of the new thr 174 /* Initialize the CPU context of the new thread */ 157 if (SOS_OK 175 if (SOS_OK 158 != sos_cpu_kstate_init(& new_thread->cpu 176 != sos_cpu_kstate_init(& new_thread->cpu_state, 159 (sos_cpu_kstate_f 177 (sos_cpu_kstate_function_arg1_t*) start_func, 160 (sos_ui32_t) star 178 (sos_ui32_t) start_arg, 161 new_thread->kerne 179 new_thread->kernel_stack_base_addr, 162 new_thread->kerne 180 new_thread->kernel_stack_size, 163 (sos_cpu_kstate_f 181 (sos_cpu_kstate_function_arg1_t*) sos_thread_exit, 164 (sos_ui32_t) NULL 182 (sos_ui32_t) NULL)) 165 goto undo_creation; 183 goto undo_creation; 166 184 167 /* Add the thread in the global list */ 185 /* Add the thread in the global list */ 168 sos_disable_IRQs(flags); 186 sos_disable_IRQs(flags); 169 list_add_tail_named(thread_list, new_thread, 187 list_add_tail_named(thread_list, new_thread, gbl_prev, gbl_next); 170 sos_restore_IRQs(flags); 188 sos_restore_IRQs(flags); 171 189 172 /* Mark the thread ready */ 190 /* Mark the thread ready */ 173 if (SOS_OK != sos_sched_set_ready(new_thread 191 if (SOS_OK != sos_sched_set_ready(new_thread)) 174 goto undo_creation; 192 goto undo_creation; 175 193 176 /* Normal non-erroneous end of function */ 194 /* Normal non-erroneous end of function */ 177 return new_thread; 195 return new_thread; 178 196 179 undo_creation: 197 undo_creation: 180 if (new_thread->kernel_stack_base_addr) 198 if (new_thread->kernel_stack_base_addr) 181 sos_kfree((sos_vaddr_t) new_thread->kernel 199 sos_kfree((sos_vaddr_t) new_thread->kernel_stack_base_addr); 182 sos_kmem_cache_free((sos_vaddr_t) new_thread 200 sos_kmem_cache_free((sos_vaddr_t) new_thread); 183 return NULL; 201 return NULL; 184 } 202 } 185 203 186 204 >> 205 /** >> 206 * Helper function to create a new user thread. If model_thread is >> 207 * given, then the new thread will be the copy of this >> 208 * thread. Otherwise the thread will have its initial SP/PC correctly >> 209 * initialized with the user_initial_PC/SP arguments >> 210 */ >> 211 static struct sos_thread * >> 212 create_user_thread(const char *name, >> 213 struct sos_process *process, >> 214 const struct sos_thread * model_thread, >> 215 const struct sos_cpu_state * model_uctxt, >> 216 sos_uaddr_t user_initial_PC, >> 217 sos_ui32_t user_start_arg1, >> 218 sos_ui32_t user_start_arg2, >> 219 sos_uaddr_t user_initial_SP, >> 220 sos_sched_priority_t priority) >> 221 { >> 222 __label__ undo_creation; >> 223 sos_ui32_t flags; >> 224 struct sos_thread *new_thread; >> 225 >> 226 if (model_thread) >> 227 { >> 228 SOS_ASSERT_FATAL(model_uctxt); >> 229 } >> 230 else >> 231 { >> 232 if (! SOS_SCHED_PRIO_IS_VALID(priority)) >> 233 return NULL; >> 234 } >> 235 >> 236 /* For a user thread, the process must be given */ >> 237 if (! process) >> 238 return NULL; >> 239 >> 240 /* Allocate a new thread structure for the current running thread */ >> 241 new_thread >> 242 = (struct sos_thread*) sos_kmem_cache_alloc(cache_thread, >> 243 SOS_KSLAB_ALLOC_ATOMIC); >> 244 if (! new_thread) >> 245 return NULL; >> 246 >> 247 /* Initialize the thread attributes */ >> 248 strzcpy(new_thread->name, ((name)?name:"[NONAME]"), SOS_THR_MAX_NAMELEN); >> 249 new_thread->state = SOS_THR_CREATED; >> 250 if (model_thread) >> 251 new_thread->priority = model_thread->priority; >> 252 else >> 253 new_thread->priority = priority; >> 254 >> 255 /* Allocate the stack for the new thread */ >> 256 new_thread->kernel_stack_base_addr = sos_kmalloc(SOS_THREAD_KERNEL_STACK_SIZE, 0); >> 257 new_thread->kernel_stack_size = SOS_THREAD_KERNEL_STACK_SIZE; >> 258 if (! new_thread->kernel_stack_base_addr) >> 259 goto undo_creation; >> 260 >> 261 /* Initialize the CPU context of the new thread */ >> 262 if (model_thread) >> 263 { >> 264 if (SOS_OK >> 265 != sos_cpu_ustate_duplicate(& new_thread->cpu_state, >> 266 model_uctxt, >> 267 user_start_arg1, >> 268 new_thread->kernel_stack_base_addr, >> 269 new_thread->kernel_stack_size)) >> 270 goto undo_creation; >> 271 } >> 272 else >> 273 { >> 274 if (SOS_OK >> 275 != sos_cpu_ustate_init(& new_thread->cpu_state, >> 276 user_initial_PC, >> 277 user_start_arg1, >> 278 user_start_arg2, >> 279 user_initial_SP, >> 280 new_thread->kernel_stack_base_addr, >> 281 new_thread->kernel_stack_size)) >> 282 goto undo_creation; >> 283 } >> 284 >> 285 /* Attach the new thread to the process */ >> 286 if (SOS_OK != sos_process_register_thread(process, new_thread)) >> 287 goto undo_creation; >> 288 >> 289 /* Add the thread in the global list */ >> 290 sos_disable_IRQs(flags); >> 291 list_add_tail_named(thread_list, new_thread, gbl_prev, gbl_next); >> 292 sos_restore_IRQs(flags); >> 293 >> 294 /* Mark the thread ready */ >> 295 if (SOS_OK != sos_sched_set_ready(new_thread)) >> 296 goto undo_creation; >> 297 >> 298 /* Normal non-erroneous end of function */ >> 299 return new_thread; >> 300 >> 301 undo_creation: >> 302 if (new_thread->kernel_stack_base_addr) >> 303 sos_kfree((sos_vaddr_t) new_thread->kernel_stack_base_addr); >> 304 sos_kmem_cache_free((sos_vaddr_t) new_thread); >> 305 return NULL; >> 306 } >> 307 >> 308 >> 309 struct sos_thread * >> 310 sos_create_user_thread(const char *name, >> 311 struct sos_process *process, >> 312 sos_uaddr_t user_initial_PC, >> 313 sos_ui32_t user_start_arg1, >> 314 sos_ui32_t user_start_arg2, >> 315 sos_uaddr_t user_initial_SP, >> 316 sos_sched_priority_t priority) >> 317 { >> 318 return create_user_thread(name, process, NULL, NULL, >> 319 user_initial_PC, >> 320 user_start_arg1, >> 321 user_start_arg2, >> 322 user_initial_SP, >> 323 priority); >> 324 } >> 325 >> 326 >> 327 /** >> 328 * Create a new user thread, copy of the given user thread with the >> 329 * given user context >> 330 */ >> 331 struct sos_thread * >> 332 sos_duplicate_user_thread(const char *name, >> 333 struct sos_process *process, >> 334 const struct sos_thread * model_thread, >> 335 const struct sos_cpu_state * model_uctxt, >> 336 sos_ui32_t retval) >> 337 { >> 338 return create_user_thread(name, process, model_thread, model_uctxt, >> 339 0, retval, 0, 0, 0); >> 340 } >> 341 >> 342 >> 343 /** >> 344 * Helper function to switch to the correct MMU configuration to suit >> 345 * the_thread's needs. >> 346 * - When switching to a user-mode thread, force the reconfiguration >> 347 * of the MMU >> 348 * - When switching to a kernel-mode thread, only change the MMU >> 349 * configuration if the thread was squatting someone else's space >> 350 */ >> 351 static void _prepare_mm_context(struct sos_thread *the_thread) >> 352 { >> 353 /* Going to restore a thread in user mode ? */ >> 354 if (sos_cpu_context_is_in_user_mode(the_thread->cpu_state) >> 355 == TRUE) >> 356 { >> 357 /* Yes: force the MMU to be correctly setup with the correct >> 358 user's address space */ >> 359 >> 360 /* The thread should be a user thread */ >> 361 SOS_ASSERT_FATAL(the_thread->process != NULL); >> 362 >> 363 /* It should not squat any other's address space */ >> 364 SOS_ASSERT_FATAL(the_thread->squatted_mm_context == NULL); >> 365 >> 366 /* Perform an MMU context switch if needed */ >> 367 sos_mm_context_switch_to(sos_process_get_mm_context(the_thread->process)); >> 368 } >> 369 >> 370 /* the_thread is a kernel thread squatting a precise address >> 371 space ? */ >> 372 else if (the_thread->squatted_mm_context != NULL) >> 373 sos_mm_context_switch_to(the_thread->squatted_mm_context); >> 374 } >> 375 >> 376 187 /** Function called after thr has terminated. 377 /** Function called after thr has terminated. Called from inside the context 188 of another thread, interrupts disabled */ 378 of another thread, interrupts disabled */ 189 static void delete_thread(struct sos_thread *t 379 static void delete_thread(struct sos_thread *thr) 190 { 380 { 191 sos_ui32_t flags; 381 sos_ui32_t flags; 192 382 193 sos_disable_IRQs(flags); 383 sos_disable_IRQs(flags); 194 list_delete_named(thread_list, thr, gbl_prev 384 list_delete_named(thread_list, thr, gbl_prev, gbl_next); 195 sos_restore_IRQs(flags); 385 sos_restore_IRQs(flags); 196 386 197 sos_kfree((sos_vaddr_t) thr->kernel_stack_ba 387 sos_kfree((sos_vaddr_t) thr->kernel_stack_base_addr); >> 388 >> 389 /* If the thread squats an address space, release it */ >> 390 if (thr->squatted_mm_context) >> 391 SOS_ASSERT_FATAL(SOS_OK == change_current_mm_context(NULL)); >> 392 >> 393 /* For a user thread: remove the thread from the process threads' list */ >> 394 if (thr->process) >> 395 SOS_ASSERT_FATAL(SOS_OK == sos_process_unregister_thread(thr)); >> 396 198 memset(thr, 0x0, sizeof(struct sos_thread)); 397 memset(thr, 0x0, sizeof(struct sos_thread)); 199 sos_kmem_cache_free((sos_vaddr_t) thr); 398 sos_kmem_cache_free((sos_vaddr_t) thr); 200 } 399 } 201 400 202 401 203 void sos_thread_exit() 402 void sos_thread_exit() 204 { 403 { 205 sos_ui32_t flags; 404 sos_ui32_t flags; 206 struct sos_thread *myself, *next_thread; 405 struct sos_thread *myself, *next_thread; 207 406 208 /* Interrupt handlers are NOT allowed to exi 407 /* Interrupt handlers are NOT allowed to exit the current thread ! */ 209 SOS_ASSERT_FATAL(! sos_servicing_irq()); 408 SOS_ASSERT_FATAL(! sos_servicing_irq()); 210 409 211 myself = sos_thread_get_current(); 410 myself = sos_thread_get_current(); 212 411 213 /* Refuse to end the current executing threa 412 /* Refuse to end the current executing thread if it still holds a 214 resource ! */ 413 resource ! */ 215 SOS_ASSERT_FATAL(list_is_empty_named(myself- 414 SOS_ASSERT_FATAL(list_is_empty_named(myself->kwaitq_list, 216 prev_en 415 prev_entry_for_thread, 217 next_en 416 next_entry_for_thread)); 218 417 219 /* Prepare to run the next thread */ 418 /* Prepare to run the next thread */ 220 sos_disable_IRQs(flags); 419 sos_disable_IRQs(flags); 221 myself->state = SOS_THR_ZOMBIE; 420 myself->state = SOS_THR_ZOMBIE; 222 next_thread = sos_reschedule(myself, FALSE); 421 next_thread = sos_reschedule(myself, FALSE); 223 422 224 /* Make sure that the next_thread is valid * 423 /* Make sure that the next_thread is valid */ 225 sos_cpu_state_detect_kernel_stack_overflow(n 424 sos_cpu_state_detect_kernel_stack_overflow(next_thread->cpu_state, 226 n 425 next_thread->kernel_stack_base_addr, 227 n 426 next_thread->kernel_stack_size); 228 427 >> 428 /* >> 429 * Perform an MMU context switch if needed >> 430 */ >> 431 _prepare_mm_context(next_thread); >> 432 229 /* No need for sos_restore_IRQs() here becau 433 /* No need for sos_restore_IRQs() here because the IRQ flag will be 230 restored to that of the next thread upon 434 restored to that of the next thread upon context switch */ 231 435 232 /* Immediate switch to next thread */ 436 /* Immediate switch to next thread */ 233 _set_current(next_thread); 437 _set_current(next_thread); 234 sos_cpu_context_exit_to(next_thread->cpu_sta 438 sos_cpu_context_exit_to(next_thread->cpu_state, 235 (sos_cpu_kstate_func 439 (sos_cpu_kstate_function_arg1_t*) delete_thread, 236 (sos_ui32_t) myself) 440 (sos_ui32_t) myself); 237 } 441 } 238 442 239 443 >> 444 sos_sched_priority_t sos_thread_get_priority(struct sos_thread *thr) >> 445 { >> 446 if (! thr) >> 447 thr = (struct sos_thread*)current_thread; >> 448 >> 449 return thr->priority; >> 450 } >> 451 >> 452 240 sos_thread_state_t sos_thread_get_state(struct 453 sos_thread_state_t sos_thread_get_state(struct sos_thread *thr) 241 { 454 { 242 if (! thr) 455 if (! thr) 243 thr = (struct sos_thread*)current_thread; 456 thr = (struct sos_thread*)current_thread; 244 457 245 return thr->state; 458 return thr->state; 246 } 459 } 247 460 248 461 249 typedef enum { YIELD_MYSELF, BLOCK_MYSELF } sw 462 typedef enum { YIELD_MYSELF, BLOCK_MYSELF } switch_type_t; 250 /** 463 /** 251 * Helper function to initiate a context switc 464 * Helper function to initiate a context switch in case the current 252 * thread becomes blocked, waiting for a timeo 465 * thread becomes blocked, waiting for a timeout, or calls yield. 253 */ 466 */ 254 static sos_ret_t _switch_to_next_thread(switch 467 static sos_ret_t _switch_to_next_thread(switch_type_t operation) 255 { 468 { 256 struct sos_thread *myself, *next_thread; 469 struct sos_thread *myself, *next_thread; 257 470 258 SOS_ASSERT_FATAL(current_thread->state == SO 471 SOS_ASSERT_FATAL(current_thread->state == SOS_THR_RUNNING); 259 472 260 /* Interrupt handlers are NOT allowed to blo 473 /* Interrupt handlers are NOT allowed to block ! */ 261 SOS_ASSERT_FATAL(! sos_servicing_irq()); 474 SOS_ASSERT_FATAL(! sos_servicing_irq()); 262 475 263 myself = (struct sos_thread*)current_thread; 476 myself = (struct sos_thread*)current_thread; 264 477 265 /* Make sure that if we are to be marked "BL 478 /* Make sure that if we are to be marked "BLOCKED", we have any 266 reason of effectively being blocked */ 479 reason of effectively being blocked */ 267 if (BLOCK_MYSELF == operation) 480 if (BLOCK_MYSELF == operation) 268 { 481 { 269 myself->state = SOS_THR_BLOCKED; 482 myself->state = SOS_THR_BLOCKED; 270 } 483 } 271 484 272 /* Identify the next thread */ 485 /* Identify the next thread */ 273 next_thread = sos_reschedule(myself, YIELD_M 486 next_thread = sos_reschedule(myself, YIELD_MYSELF == operation); 274 487 275 /* Avoid context switch if the context does 488 /* Avoid context switch if the context does not change */ 276 if (myself != next_thread) 489 if (myself != next_thread) 277 { 490 { 278 /* Sanity checks for the next thread */ 491 /* Sanity checks for the next thread */ 279 sos_cpu_state_detect_kernel_stack_overfl 492 sos_cpu_state_detect_kernel_stack_overflow(next_thread->cpu_state, 280 493 next_thread->kernel_stack_base_addr, 281 494 next_thread->kernel_stack_size); 282 495 >> 496 /* >> 497 * Perform an MMU context switch if needed >> 498 */ >> 499 _prepare_mm_context(next_thread); 283 500 284 /* 501 /* 285 * Actual CPU context switch 502 * Actual CPU context switch 286 */ 503 */ 287 _set_current(next_thread); 504 _set_current(next_thread); 288 sos_cpu_context_switch(& myself->cpu_sta 505 sos_cpu_context_switch(& myself->cpu_state, next_thread->cpu_state); 289 506 290 /* Back here ! */ 507 /* Back here ! */ 291 SOS_ASSERT_FATAL(current_thread == mysel 508 SOS_ASSERT_FATAL(current_thread == myself); 292 SOS_ASSERT_FATAL(current_thread->state = 509 SOS_ASSERT_FATAL(current_thread->state == SOS_THR_RUNNING); 293 } 510 } 294 else 511 else 295 { 512 { 296 /* No context switch but still update ID 513 /* No context switch but still update ID of current thread */ 297 _set_current(next_thread); 514 _set_current(next_thread); 298 } 515 } 299 516 300 return SOS_OK; 517 return SOS_OK; 301 } 518 } 302 519 303 520 >> 521 /** >> 522 * Helper function to change the thread's priority in all the >> 523 * waitqueues associated with the thread. >> 524 */ >> 525 static sos_ret_t _change_waitq_priorities(struct sos_thread *thr, >> 526 sos_sched_priority_t priority) >> 527 { >> 528 struct sos_kwaitq_entry *kwq_entry; >> 529 int nb_waitqs; >> 530 >> 531 list_foreach_forward_named(thr->kwaitq_list, kwq_entry, nb_waitqs, >> 532 prev_entry_for_thread, next_entry_for_thread) >> 533 { >> 534 SOS_ASSERT_FATAL(SOS_OK == sos_kwaitq_change_priority(kwq_entry->kwaitq, >> 535 kwq_entry, >> 536 priority)); >> 537 } >> 538 >> 539 return SOS_OK; >> 540 } >> 541 >> 542 >> 543 sos_ret_t sos_thread_set_priority(struct sos_thread *thr, >> 544 sos_sched_priority_t priority) >> 545 { >> 546 __label__ exit_set_prio; >> 547 sos_ui32_t flags; >> 548 sos_ret_t retval; >> 549 >> 550 >> 551 if (! SOS_SCHED_PRIO_IS_VALID(priority)) >> 552 return -SOS_EINVAL; >> 553 >> 554 if (! thr) >> 555 thr = (struct sos_thread*)current_thread; >> 556 >> 557 sos_disable_IRQs(flags); >> 558 >> 559 /* Signal kwaitq subsystem that the priority of the thread in all >> 560 the waitq it is waiting in should be updated */ >> 561 retval = _change_waitq_priorities(thr, priority); >> 562 if (SOS_OK != retval) >> 563 goto exit_set_prio; >> 564 >> 565 /* Signal scheduler that the thread, currently in a waiting list, >> 566 should take into account the change of priority */ >> 567 if (SOS_THR_READY == thr->state) >> 568 retval = sos_sched_change_priority(thr, priority); >> 569 >> 570 /* Update priority */ >> 571 thr->priority = priority; >> 572 >> 573 exit_set_prio: >> 574 sos_restore_IRQs(flags); >> 575 return retval; >> 576 } >> 577 >> 578 304 sos_ret_t sos_thread_yield() 579 sos_ret_t sos_thread_yield() 305 { 580 { 306 sos_ui32_t flags; 581 sos_ui32_t flags; 307 sos_ret_t retval; 582 sos_ret_t retval; 308 583 309 sos_disable_IRQs(flags); 584 sos_disable_IRQs(flags); 310 585 311 retval = _switch_to_next_thread(YIELD_MYSELF 586 retval = _switch_to_next_thread(YIELD_MYSELF); 312 587 313 sos_restore_IRQs(flags); 588 sos_restore_IRQs(flags); 314 return retval; 589 return retval; 315 } 590 } 316 591 317 592 318 /** 593 /** 319 * Internal sleep timeout management 594 * Internal sleep timeout management 320 */ 595 */ 321 struct sleep_timeout_params 596 struct sleep_timeout_params 322 { 597 { 323 struct sos_thread *thread_to_wakeup; 598 struct sos_thread *thread_to_wakeup; 324 sos_bool_t timeout_triggered; 599 sos_bool_t timeout_triggered; 325 }; 600 }; 326 601 327 602 328 /** 603 /** 329 * Callback called when a timeout happened 604 * Callback called when a timeout happened 330 */ 605 */ 331 static void sleep_timeout(struct sos_timeout_a 606 static void sleep_timeout(struct sos_timeout_action *act) 332 { 607 { 333 struct sleep_timeout_params *sleep_timeout_p 608 struct sleep_timeout_params *sleep_timeout_params 334 = (struct sleep_timeout_params*) act->rout 609 = (struct sleep_timeout_params*) act->routine_data; 335 610 336 /* Signal that we have been woken up by the 611 /* Signal that we have been woken up by the timeout */ 337 sleep_timeout_params->timeout_triggered = TR 612 sleep_timeout_params->timeout_triggered = TRUE; 338 613 339 /* Mark the thread ready */ 614 /* Mark the thread ready */ 340 SOS_ASSERT_FATAL(SOS_OK == 615 SOS_ASSERT_FATAL(SOS_OK == 341 sos_thread_force_unblock(sl 616 sos_thread_force_unblock(sleep_timeout_params 342 - 617 ->thread_to_wakeup)); 343 } 618 } 344 619 345 620 346 sos_ret_t sos_thread_sleep(struct sos_time *ti 621 sos_ret_t sos_thread_sleep(struct sos_time *timeout) 347 { 622 { 348 sos_ui32_t flags; 623 sos_ui32_t flags; 349 struct sleep_timeout_params sleep_timeout_pa 624 struct sleep_timeout_params sleep_timeout_params; 350 struct sos_timeout_action timeout_action; 625 struct sos_timeout_action timeout_action; 351 sos_ret_t retval; 626 sos_ret_t retval; 352 627 353 /* Block forever if no timeout is given */ 628 /* Block forever if no timeout is given */ 354 if (NULL == timeout) 629 if (NULL == timeout) 355 { 630 { 356 sos_disable_IRQs(flags); 631 sos_disable_IRQs(flags); 357 retval = _switch_to_next_thread(BLOCK_MY 632 retval = _switch_to_next_thread(BLOCK_MYSELF); 358 sos_restore_IRQs(flags); 633 sos_restore_IRQs(flags); 359 634 360 return retval; 635 return retval; 361 } 636 } 362 637 363 /* Initialize the timeout action */ 638 /* Initialize the timeout action */ 364 sos_time_init_action(& timeout_action); 639 sos_time_init_action(& timeout_action); 365 640 366 /* Prepare parameters used by the sleep time 641 /* Prepare parameters used by the sleep timeout callback */ 367 sleep_timeout_params.thread_to_wakeup 642 sleep_timeout_params.thread_to_wakeup 368 = (struct sos_thread*)current_thread; 643 = (struct sos_thread*)current_thread; 369 sleep_timeout_params.timeout_triggered = FAL 644 sleep_timeout_params.timeout_triggered = FALSE; 370 645 371 sos_disable_IRQs(flags); 646 sos_disable_IRQs(flags); 372 647 373 /* Now program the timeout ! */ 648 /* Now program the timeout ! */ 374 SOS_ASSERT_FATAL(SOS_OK == 649 SOS_ASSERT_FATAL(SOS_OK == 375 sos_time_register_action_re 650 sos_time_register_action_relative(& timeout_action, 376 651 timeout, 377 652 sleep_timeout, 378 653 & sleep_timeout_params)); 379 654 380 /* Prepare to block: wait for sleep_timeout( 655 /* Prepare to block: wait for sleep_timeout() to wakeup us in the 381 timeout kwaitq, or for someone to wake us 656 timeout kwaitq, or for someone to wake us up in any other 382 waitq */ 657 waitq */ 383 retval = _switch_to_next_thread(BLOCK_MYSELF 658 retval = _switch_to_next_thread(BLOCK_MYSELF); 384 /* Unblocked by something ! */ 659 /* Unblocked by something ! */ 385 660 386 /* Unblocked by timeout ? */ 661 /* Unblocked by timeout ? */ 387 if (sleep_timeout_params.timeout_triggered) 662 if (sleep_timeout_params.timeout_triggered) 388 { 663 { 389 /* Yes */ 664 /* Yes */ 390 SOS_ASSERT_FATAL(sos_time_is_zero(& time 665 SOS_ASSERT_FATAL(sos_time_is_zero(& timeout_action.timeout)); 391 retval = SOS_OK; 666 retval = SOS_OK; 392 } 667 } 393 else 668 else 394 { 669 { 395 /* No: We have probably been woken up wh 670 /* No: We have probably been woken up while in some other 396 kwaitq */ 671 kwaitq */ 397 SOS_ASSERT_FATAL(SOS_OK == sos_time_unre 672 SOS_ASSERT_FATAL(SOS_OK == sos_time_unregister_action(& timeout_action)); 398 retval = -SOS_EINTR; 673 retval = -SOS_EINTR; 399 } 674 } 400 675 401 sos_restore_IRQs(flags); 676 sos_restore_IRQs(flags); 402 677 403 /* Update the remaining timeout */ 678 /* Update the remaining timeout */ 404 memcpy(timeout, & timeout_action.timeout, si 679 memcpy(timeout, & timeout_action.timeout, sizeof(struct sos_time)); 405 680 406 return retval; 681 return retval; 407 } 682 } 408 683 409 684 410 sos_ret_t sos_thread_force_unblock(struct sos_ 685 sos_ret_t sos_thread_force_unblock(struct sos_thread *thread) 411 { 686 { 412 sos_ret_t retval; 687 sos_ret_t retval; 413 sos_ui32_t flags; 688 sos_ui32_t flags; 414 689 415 if (! thread) 690 if (! thread) 416 return -SOS_EINVAL; 691 return -SOS_EINVAL; 417 692 418 sos_disable_IRQs(flags); 693 sos_disable_IRQs(flags); 419 694 420 /* Thread already woken up ? */ 695 /* Thread already woken up ? */ 421 retval = SOS_OK; 696 retval = SOS_OK; 422 switch(sos_thread_get_state(thread)) 697 switch(sos_thread_get_state(thread)) 423 { 698 { 424 case SOS_THR_RUNNING: 699 case SOS_THR_RUNNING: 425 case SOS_THR_READY: 700 case SOS_THR_READY: 426 /* Do nothing */ 701 /* Do nothing */ 427 break; 702 break; 428 703 429 case SOS_THR_ZOMBIE: 704 case SOS_THR_ZOMBIE: 430 retval = -SOS_EFATAL; 705 retval = -SOS_EFATAL; 431 break; 706 break; 432 707 433 default: 708 default: 434 retval = sos_sched_set_ready(thread); 709 retval = sos_sched_set_ready(thread); 435 break; 710 break; 436 } 711 } 437 712 438 sos_restore_IRQs(flags); 713 sos_restore_IRQs(flags); 439 714 440 return retval; 715 return retval; >> 716 } >> 717 >> 718 >> 719 void sos_thread_dump_backtrace(sos_bool_t on_console, >> 720 sos_bool_t on_bochs) >> 721 { >> 722 sos_vaddr_t stack_bottom = current_thread->kernel_stack_base_addr; >> 723 sos_size_t stack_size = current_thread->kernel_stack_size; >> 724 >> 725 static void backtracer(sos_vaddr_t PC, >> 726 sos_vaddr_t params, >> 727 sos_ui32_t depth, >> 728 void *custom_arg) >> 729 { >> 730 sos_ui32_t invalid = 0xffffffff, *arg1, *arg2, *arg3, *arg4; >> 731 >> 732 /* Get the address of the first 3 arguments from the >> 733 frame. Among these arguments, 0, 1, 2, 3 arguments might be >> 734 meaningful (depending on how many arguments the function may >> 735 take). */ >> 736 arg1 = (sos_ui32_t*)params; >> 737 arg2 = (sos_ui32_t*)(params+4); >> 738 arg3 = (sos_ui32_t*)(params+8); >> 739 arg4 = (sos_ui32_t*)(params+12); >> 740 >> 741 /* Make sure the addresses of these arguments fit inside the >> 742 stack boundaries */ >> 743 #define INTERVAL_OK(b,v,u) ( ((b) <= (sos_vaddr_t)(v)) \ >> 744 && ((sos_vaddr_t)(v) < (u)) ) >> 745 if (!INTERVAL_OK(stack_bottom, arg1, stack_bottom + stack_size)) >> 746 arg1 = &invalid; >> 747 if (!INTERVAL_OK(stack_bottom, arg2, stack_bottom + stack_size)) >> 748 arg2 = &invalid; >> 749 if (!INTERVAL_OK(stack_bottom, arg3, stack_bottom + stack_size)) >> 750 arg3 = &invalid; >> 751 if (!INTERVAL_OK(stack_bottom, arg4, stack_bottom + stack_size)) >> 752 arg4 = &invalid; >> 753 >> 754 /* Print the function context for this frame */ >> 755 if (on_bochs) >> 756 sos_bochs_printf("[%d] PC=0x%x arg1=0x%x arg2=0x%x arg3=0x%x\n", >> 757 (unsigned)depth, (unsigned)PC, >> 758 (unsigned)*arg1, (unsigned)*arg2, >> 759 (unsigned)*arg3); >> 760 >> 761 if (on_console) >> 762 sos_x86_videomem_printf(23-depth, 3, >> 763 SOS_X86_VIDEO_BG_BLUE >> 764 | SOS_X86_VIDEO_FG_LTGREEN, >> 765 "[%d] PC=0x%x arg1=0x%x arg2=0x%x arg3=0x%x arg4=0x%x", >> 766 (unsigned)depth, PC, >> 767 (unsigned)*arg1, (unsigned)*arg2, >> 768 (unsigned)*arg3, (unsigned)*arg4); >> 769 >> 770 } >> 771 >> 772 sos_backtrace(NULL, 15, stack_bottom, stack_size, >> 773 backtracer, NULL); >> 774 } >> 775 >> 776 >> 777 >> 778 /* ********************************************** >> 779 * Restricted functions >> 780 */ >> 781 >> 782 >> 783 static sos_ret_t >> 784 change_current_mm_context(struct sos_mm_context *mm_ctxt) >> 785 { >> 786 /* Retrieve the previous mm context */ >> 787 struct sos_mm_context * prev_mm_ctxt >> 788 = current_thread->squatted_mm_context; >> 789 >> 790 /* Update current thread's squatted mm context */ >> 791 current_thread->squatted_mm_context = mm_ctxt; >> 792 >> 793 /* Update the reference counts and switch the MMU configuration if >> 794 needed */ >> 795 if (mm_ctxt != NULL) >> 796 { >> 797 sos_mm_context_ref(mm_ctxt); /* Because it is now referenced as >> 798 the squatted_mm_context field of >> 799 the thread */ >> 800 sos_mm_context_switch_to(mm_ctxt); >> 801 } >> 802 else >> 803 sos_mm_context_unref(prev_mm_ctxt); /* Because it is not referenced as >> 804 the squatted_mm_context field of >> 805 the thread any more */ >> 806 >> 807 return SOS_OK; >> 808 } >> 809 >> 810 >> 811 sos_ret_t >> 812 sos_thread_prepare_user_space_access(struct sos_umem_vmm_as * dest_as, >> 813 sos_vaddr_t fixup_retvaddr) >> 814 { >> 815 sos_ret_t retval; >> 816 sos_ui32_t flags; >> 817 >> 818 if (! dest_as) >> 819 { >> 820 /* Thread is not a user thread: do nothing */ >> 821 if (! current_thread->process) >> 822 return -SOS_EINVAL; >> 823 >> 824 dest_as = sos_process_get_address_space(current_thread->process); >> 825 } >> 826 else >> 827 /* Don't allow to access to an address space different than that >> 828 of the current thread if the page fault are allowed ! */ >> 829 SOS_ASSERT_FATAL(! fixup_retvaddr); >> 830 >> 831 sos_disable_IRQs(flags); >> 832 SOS_ASSERT_FATAL(NULL == current_thread->squatted_mm_context); >> 833 SOS_ASSERT_FATAL(0 == current_thread->fixup_uaccess.return_vaddr); >> 834 >> 835 /* Change the MMU configuration and init the fixup return address */ >> 836 retval = change_current_mm_context(sos_umem_vmm_get_mm_context(dest_as)); >> 837 if (SOS_OK == retval) >> 838 { >> 839 current_thread->fixup_uaccess.return_vaddr = fixup_retvaddr; >> 840 current_thread->fixup_uaccess.faulted_uaddr = 0; >> 841 } >> 842 >> 843 sos_restore_IRQs(flags); >> 844 return retval; >> 845 } >> 846 >> 847 >> 848 sos_ret_t >> 849 sos_thread_end_user_space_access(void) >> 850 { >> 851 sos_ret_t retval; >> 852 sos_ui32_t flags; >> 853 >> 854 sos_disable_IRQs(flags); >> 855 SOS_ASSERT_FATAL(NULL != current_thread->squatted_mm_context); >> 856 >> 857 /* Don't impose anything regarding the current MMU configuration anymore */ >> 858 retval = change_current_mm_context(NULL); >> 859 current_thread->fixup_uaccess.return_vaddr = 0; >> 860 current_thread->fixup_uaccess.faulted_uaddr = 0; >> 861 >> 862 sos_restore_IRQs(flags); >> 863 return retval; >> 864 } >> 865 >> 866 >> 867 void sos_thread_prepare_syscall_switch_back(struct sos_cpu_state *cpu_state) >> 868 { >> 869 /* Don't preempt the current thread */ >> 870 >> 871 /* >> 872 * Save the state of the interrupted context to make sure that: >> 873 * - The list of threads correctly reflects that the thread is back >> 874 * in user mode >> 875 * - _prepare_mm_context() deals with the correct mm_context >> 876 */ >> 877 current_thread->cpu_state = cpu_state; >> 878 >> 879 /* Perform an MMU context switch if needed */ >> 880 _prepare_mm_context((struct sos_thread*) current_thread); >> 881 } >> 882 >> 883 >> 884 void sos_thread_prepare_exception_switch_back(struct sos_cpu_state *cpu_state) >> 885 { >> 886 /* Don't preempt the current thread */ >> 887 >> 888 /* >> 889 * Save the state of the interrupted context to make sure that: >> 890 * - The list of threads correctly reflects that the thread is >> 891 * running in user or kernel mode >> 892 * - _prepare_mm_context() deals with the correct mm_context >> 893 */ >> 894 current_thread->cpu_state = cpu_state; >> 895 >> 896 /* Perform an MMU context switch if needed */ >> 897 _prepare_mm_context((struct sos_thread*) current_thread); >> 898 } >> 899 >> 900 >> 901 void >> 902 sos_thread_prepare_irq_servicing(struct sos_cpu_state *interrupted_state) >> 903 { >> 904 current_thread->cpu_state = interrupted_state; >> 905 } >> 906 >> 907 >> 908 struct sos_cpu_state * >> 909 sos_thread_prepare_irq_switch_back(void) >> 910 { >> 911 struct sos_thread *myself, *next_thread; >> 912 >> 913 /* In SOS, threads in kernel mode are NEVER preempted from the >> 914 interrupt handlers ! */ >> 915 if (! sos_cpu_context_is_in_user_mode(current_thread->cpu_state)) >> 916 return current_thread->cpu_state; >> 917 >> 918 /* >> 919 * Here we are dealing only with possible preemption of user threads >> 920 * in user context ! >> 921 */ >> 922 >> 923 /* Make sure the thread actually is a user thread */ >> 924 SOS_ASSERT_FATAL(current_thread->process != NULL); >> 925 >> 926 /* Save the state of the interrupted context */ >> 927 myself = (struct sos_thread*)current_thread; >> 928 >> 929 /* Select the next thread to run */ >> 930 next_thread = sos_reschedule(myself, FALSE); >> 931 >> 932 /* Perform an MMU context switch if needed */ >> 933 _prepare_mm_context(next_thread); >> 934 >> 935 /* Setup the next_thread's context into the CPU */ >> 936 _set_current(next_thread); >> 937 return next_thread->cpu_state; 441 } 938 }
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