bertos/cpu/irq.h

   1 /**
   2  * \file
   3  * <!--
   4  * This file is part of BeRTOS.
   5  *
   6  * Bertos is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  * As a special exception, you may use this file as part of a free software
  21  * library without restriction.  Specifically, if other files instantiate
  22  * templates or use macros or inline functions from this file, or you compile
  23  * this file and link it with other files to produce an executable, this
  24  * file does not by itself cause the resulting executable to be covered by
  25  * the GNU General Public License.  This exception does not however
  26  * invalidate any other reasons why the executable file might be covered by
  27  * the GNU General Public License.
  28  *
  29  * Copyright 2004, 2005, 2006, 2007 Develer S.r.l. (http://www.develer.com/)
  30  * Copyright 2004 Giovanni Bajo
  31  *
  32  * -->
  33  *
  34  * \brief CPU-specific IRQ definitions.
  35  *
  36  * \author Giovanni Bajo <rasky@develer.com>
  37  * \author Bernie Innocenti <bernie@codewiz.org>
  38  * \author Stefano Fedrigo <aleph@develer.com>
  39  * \author Francesco Sacchi <batt@develer.com>
  40  */
  41 #ifndef CPU_IRQ_H
  42 #define CPU_IRQ_H
  43
  44 #include "detect.h"
  45 #include "types.h"
  46
  47 #include <kern/proc.h> /* proc_needPreempt() / proc_preempt() */
  48
  49 #include <cfg/compiler.h> /* for uintXX_t */
  50 #include "cfg/cfg_proc.h" /* CONFIG_KERN_PREEMPT */
  51
  52 #if CPU_I196
  53         #define IRQ_DISABLE             disable_interrupt()
  54         #define IRQ_ENABLE              enable_interrupt()
  55 #elif CPU_X86
  56
  57         /* Get IRQ_* definitions from the hosting environment. */
  58         #include <cfg/os.h>
  59         #if OS_EMBEDDED
  60                 #define IRQ_DISABLE             FIXME
  61                 #define IRQ_ENABLE              FIXME
  62                 #define IRQ_SAVE_DISABLE(x)     FIXME
  63                 #define IRQ_RESTORE(x)          FIXME
  64         #endif /* OS_EMBEDDED */
  65
  66 #elif CPU_CM3
  67         /* Cortex-M3 */
  68
  69         /*
  70          * Interrupt priority.
  71          *
  72          * NOTE: 0 means that an interrupt is not affected by the global IRQ
  73          * priority settings.
  74          */
  75         #define IRQ_PRIO                0x80
  76         #define IRQ_PRIO_MIN            0xf0
  77         #define IRQ_PRIO_MAX            0
  78         /*
  79          * To disable interrupts we just raise the system base priority to a
  80          * number lower than the default IRQ priority. In this way, all the
  81          * "normal" interrupt can't be triggered. High-priority interrupt can
  82          * still happen (at the moment only the soft-interrupt svcall uses a
  83          * priority greater than the default IRQ priority).
  84          *
  85          * To enable interrupts we set the system base priority to 0, that
  86          * means IRQ priority mechanism is disabled, and any interrupt can
  87          * happen.
  88          */
  89         #define IRQ_PRIO_DISABLED       0x40
  90         #define IRQ_PRIO_ENABLED        0
  91
  92         #define IRQ_DISABLE                                             \
  93         ({                                                              \
  94                 register cpu_flags_t reg = IRQ_PRIO_DISABLED;           \
  95                 asm volatile (                                          \
  96                         "msr basepri, %0"                               \
  97                         : : "r"(reg) : "memory", "cc");                 \
  98         })
  99
 100         #define IRQ_ENABLE                                              \
 101         ({                                                              \
 102                 register cpu_flags_t reg = IRQ_PRIO_ENABLED;            \
 103                 asm volatile (                                          \
 104                         "msr basepri, %0"                               \
 105                         : : "r"(reg) : "memory", "cc");                 \
 106         })
 107
 108         #define CPU_READ_FLAGS()                                        \
 109         ({                                                              \
 110                 register cpu_flags_t reg;                               \
 111                 asm volatile (                                          \
 112                         "mrs %0, basepri"                               \
 113                          : "=r"(reg) : : "memory", "cc");               \
 114                 reg;                                                    \
 115         })
 116
 117         #define IRQ_SAVE_DISABLE(x)                                     \
 118         ({                                                              \
 119                 x = CPU_READ_FLAGS();                                   \
 120                 IRQ_DISABLE;                                            \
 121         })
 122
 123         #define IRQ_RESTORE(x)                                          \
 124         ({                                                              \
 125                 asm volatile (                                          \
 126                         "msr basepri, %0"                               \
 127                         : : "r"(x) : "memory", "cc");                   \
 128         })
 129
 130         #define IRQ_ENABLED() (CPU_READ_FLAGS() == IRQ_PRIO_ENABLED)
 131
 132         INLINE bool irq_running(void)
 133         {
 134                 register uint32_t ret;
 135
 136                 /*
 137                  * Check if the current stack pointer is the main stack or
 138                  * process stack: we use the main stack only in Handler mode,
 139                  * so this means we're running inside an ISR.
 140                  */
 141                 asm volatile (
 142                         "mrs %0, msp\n\t"
 143                         "cmp sp, %0\n\t"
 144                         "ite ne\n\t"
 145                         "movne %0, #0\n\t"
 146                         "moveq %0, #1\n\t" : "=r"(ret) : : "cc");
 147                 return ret;
 148         }
 149         #define IRQ_RUNNING() irq_running()
 150
 151         #if CONFIG_KERN_PREEMPT
 152
 153                 #define DECLARE_ISR_CONTEXT_SWITCH(func)                \
 154                 void func(void);                                        \
 155                 INLINE void __isr_##func(void);                         \
 156                 void func(void)                                         \
 157                 {                                                       \
 158                         __isr_##func();                                 \
 159                         if (!proc_needPreempt())                        \
 160                                 return;                                 \
 161                         /*
 162                          * Set a PendSV request.
 163                          *
 164                          * The preemption handler will be called immediately
 165                          * after this ISR in tail-chaining mode (without the
 166                          * overhead of hardware state saving and restoration
 167                          * between interrupts).
 168                          */                                             \
 169                         HWREG(NVIC_INT_CTRL) = NVIC_INT_CTRL_PEND_SV;   \
 170                 }                                                       \
 171                 INLINE void __isr_##func(void)
 172
 173                 /**
 174                  * With task priorities enabled each ISR is used a point to
 175                  * check if we need to perform a context switch.
 176                  *
 177                  * Instead, without priorities a context switch can occur only
 178                  * when the running task expires its time quantum. In this last
 179                  * case, the context switch can only occur in the timer ISR,
 180                  * that must be always declared with the
 181                  * DECLARE_ISR_CONTEXT_SWITCH() macro.
 182                  */
 183                 #if CONFIG_KERN_PRI
 184                         #define DECLARE_ISR(func) \
 185                                 DECLARE_ISR_CONTEXT_SWITCH(func)
 186                         /**
 187                          * Interrupt service routine prototype: can be used for
 188                          * forward declarations.
 189                          */
 190                         #define ISR_PROTO(func) \
 191                                 ISR_PROTO_CONTEXT_SWITCH(func)
 192                 #endif /* !CONFIG_KERN_PRI */
 193         #endif
 194
 195         #ifndef ISR_PROTO
 196                 #define ISR_PROTO(func) void func(void)
 197         #endif
 198         #ifndef DECLARE_ISR
 199                 #define DECLARE_ISR(func) void func(void)
 200         #endif
 201         #ifndef DECLARE_ISR_CONTEXT_SWITCH
 202                 #define DECLARE_ISR_CONTEXT_SWITCH(func) void func(void)
 203         #endif
 204         #ifndef ISR_PROTO_CONTEXT_SWITCH
 205                 #define ISR_PROTO_CONTEXT_SWITCH(func) void func(void)
 206         #endif
 207
 208 #elif CPU_ARM
 209
 210         #ifdef __IAR_SYSTEMS_ICC__
 211
 212                 #include <inarm.h>
 213
 214                 #if __CPU_MODE__ == 1 /* Thumb */
 215                         /* Use stubs */
 216                         extern cpu_flags_t get_CPSR(void);
 217                         extern void set_CPSR(cpu_flags_t flags);
 218                 #else
 219                         #define get_CPSR __get_CPSR
 220                         #define set_CPSR __set_CPSR
 221                 #endif
 222
 223                 #define IRQ_DISABLE __disable_interrupt()
 224                 #define IRQ_ENABLE  __enable_interrupt()
 225
 226                 #define IRQ_SAVE_DISABLE(x) \
 227                 do { \
 228                         (x) = get_CPSR(); \
 229                         __disable_interrupt(); \
 230                 } while (0)
 231
 232                 #define IRQ_RESTORE(x) \
 233                 do { \
 234                         set_CPSR(x); \
 235                 } while (0)
 236
 237                 #define IRQ_ENABLED() \
 238                         ((bool)(get_CPSR() & 0xb0))
 239
 240         #else /* !__IAR_SYSTEMS_ICC__ */
 241
 242                 #define IRQ_DISABLE \
 243                 do { \
 244                         asm volatile ( \
 245                                 "mrs r0, cpsr\n\t" \
 246                                 "orr r0, r0, #0xc0\n\t" \
 247                                 "msr cpsr_c, r0" \
 248                                 ::: "r0" \
 249                         ); \
 250                 } while (0)
 251
 252                 #define IRQ_ENABLE \
 253                 do { \
 254                         asm volatile ( \
 255                                 "mrs r0, cpsr\n\t" \
 256                                 "bic r0, r0, #0xc0\n\t" \
 257                                 "msr cpsr_c, r0" \
 258                                 ::: "r0" \
 259                         ); \
 260                 } while (0)
 261
 262                 #define IRQ_SAVE_DISABLE(x) \
 263                 do { \
 264                         asm volatile ( \
 265                                 "mrs %0, cpsr\n\t" \
 266                                 "orr r0, %0, #0xc0\n\t" \
 267                                 "msr cpsr_c, r0" \
 268                                 : "=r" (x) \
 269                                 : /* no inputs */ \
 270                                 : "r0" \
 271                         ); \
 272                 } while (0)
 273
 274                 #define IRQ_RESTORE(x) \
 275                 do { \
 276                         asm volatile ( \
 277                                 "msr cpsr_c, %0" \
 278                                 : /* no outputs */ \
 279                                 : "r" (x) \
 280                         ); \
 281                 } while (0)
 282
 283                 #define CPU_READ_FLAGS() \
 284                 ({ \
 285                         cpu_flags_t sreg; \
 286                         asm volatile ( \
 287                                 "mrs %0, cpsr\n\t" \
 288                                 : "=r" (sreg) \
 289                                 : /* no inputs */ \
 290                         ); \
 291                         sreg; \
 292                 })
 293
 294                 #define IRQ_ENABLED() ((CPU_READ_FLAGS() & 0xc0) != 0xc0)
 295
 296                 #if CONFIG_KERN_PREEMPT
 297                         EXTERN_C void asm_irq_switch_context(void);
 298
 299                         /**
 300                          * At the beginning of any ISR immediately ajust the
 301                          * return address and store all the caller-save
 302                          * registers (the ISR may change these registers that
 303                          * are shared with the user-context).
 304                          */
 305                         #define IRQ_ENTRY() asm volatile ( \
 306                                                 "sub    lr, lr, #4\n\t" \
 307                                                 "stmfd  sp!, {r0-r3, ip, lr}\n\t")
 308                         #define IRQ_EXIT()  asm volatile ( \
 309                                                 "b      asm_irq_switch_context\n\t")
 310                         /**
 311                          * Function attribute to declare an interrupt service
 312                          * routine.
 313                          *
 314                          * An ISR function must be declared as naked because we
 315                          * want to add our IRQ_ENTRY() prologue and IRQ_EXIT()
 316                          * epilogue code to handle the context switch and save
 317                          * all the registers (not only the callee-save).
 318                          *
 319                          */
 320                         #define ISR_FUNC __attribute__((naked))
 321
 322                         /**
 323                          * The compiler cannot establish which
 324                          * registers actually need to be saved, because
 325                          * the interrupt can happen at any time, so the
 326                          * "normal" prologue and epilogue used for a
 327                          * generic function call are not suitable for
 328                          * the ISR.
 329                          *
 330                          * Using a naked function has the drawback that
 331                          * the stack is not automatically adjusted at
 332                          * this point, like a "normal" function call.
 333                          *
 334                          * So, an ISR can _only_ contain other function
 335                          * calls and they can't use the stack in any
 336                          * other way.
 337                          *
 338                          * NOTE: we need to explicitly disable IRQs after
 339                          * IRQ_ENTRY(), because the IRQ status flag is not
 340                          * masked by the hardware and an IRQ ack inside the ISR
 341                          * may cause the triggering of another IRQ before
 342                          * exiting from the current ISR.
 343                          *
 344                          * The respective IRQ_ENABLE is not necessary, because
 345                          * IRQs will be automatically re-enabled when restoring
 346                          * the context of the user task.
 347                          */
 348                         #define DECLARE_ISR_CONTEXT_SWITCH(func)        \
 349                                 void ISR_FUNC func(void);               \
 350                                 static void __isr_##func(void);         \
 351                                 void ISR_FUNC func(void)                \
 352                                 {                                       \
 353                                         IRQ_ENTRY();                    \
 354                                         IRQ_DISABLE;                    \
 355                                         __isr_##func();                 \
 356                                         IRQ_EXIT();                     \
 357                                 }                                       \
 358                                 static void __isr_##func(void)
 359                         /**
 360                          * Interrupt service routine prototype: can be used for
 361                          * forward declarations.
 362                          */
 363                         #define ISR_PROTO_CONTEXT_SWITCH(func)  \
 364                                 void ISR_FUNC func(void)
 365                         /**
 366                          * With task priorities enabled each ISR is used a point to
 367                          * check if we need to perform a context switch.
 368                          *
 369                          * Instead, without priorities a context switch can occur only
 370                          * when the running task expires its time quantum. In this last
 371                          * case, the context switch can only occur in the timer
 372                          * ISR, that must be always declared with the
 373                          * DECLARE_ISR_CONTEXT_SWITCH() macro.
 374                          */
 375                         #if CONFIG_KERN_PRI
 376                                 #define DECLARE_ISR(func) \
 377                                         DECLARE_ISR_CONTEXT_SWITCH(func)
 378
 379                                 #define ISR_PROTO(func) \
 380                                         ISR_PROTO_CONTEXT_SWITCH(func)
 381                         #endif /* !CONFIG_KERN_PRI */
 382                 #endif /* CONFIG_KERN_PREEMPT */
 383
 384                 #ifndef DECLARE_ISR
 385                         #define DECLARE_ISR(func) \
 386                                 void __attribute__((interrupt)) func(void)
 387                 #endif
 388                 #ifndef DECLARE_ISR_CONTEXT_SWITCH
 389                         #define DECLARE_ISR_CONTEXT_SWITCH(func) \
 390                                 void __attribute__((interrupt)) func(void)
 391                 #endif
 392                 #ifndef ISR_PROTO
 393                         #define ISR_PROTO(func) \
 394                                 void __attribute__((interrupt)) func(void)
 395                 #endif
 396                 #ifndef ISR_PROTO_CONTEXT_SWITCH
 397                         #define ISR_PROTO_CONTEXT_SWITCH(func)  \
 398                                 void __attribute__((interrupt)) func(void)
 399                 #endif
 400
 401         #endif /* !__IAR_SYSTEMS_ICC_ */
 402
 403 #elif CPU_PPC
 404
 405         /* Get IRQ_* definitions from the hosting environment. */
 406         #include <cfg/os.h>
 407         #if OS_EMBEDDED
 408                 #define IRQ_DISABLE         FIXME
 409                 #define IRQ_ENABLE          FIXME
 410                 #define IRQ_SAVE_DISABLE(x) FIXME
 411                 #define IRQ_RESTORE(x)      FIXME
 412                 #define IRQ_ENABLED()       FIXME
 413         #endif /* OS_EMBEDDED */
 414
 415 #elif CPU_DSP56K
 416
 417         #define IRQ_DISABLE             do { asm(bfset #0x0200,SR); asm(nop); } while (0)
 418         #define IRQ_ENABLE              do { asm(bfclr #0x0200,SR); asm(nop); } while (0)
 419
 420         #define IRQ_SAVE_DISABLE(x)  \
 421                 do { (void)x; asm(move SR,x); asm(bfset #0x0200,SR); } while (0)
 422         #define IRQ_RESTORE(x)  \
 423                 do { (void)x; asm(move x,SR); } while (0)
 424
 425         static inline bool irq_running(void)
 426         {
 427                 extern void *user_sp;
 428                 return !!user_sp;
 429         }
 430         #define IRQ_RUNNING() irq_running()
 431
 432         static inline bool irq_enabled(void)
 433         {
 434                 uint16_t x;
 435                 asm(move SR,x);
 436                 return !(x & 0x0200);
 437         }
 438         #define IRQ_ENABLED() irq_enabled()
 439
 440 #elif CPU_AVR
 441
 442         #define IRQ_DISABLE   asm volatile ("cli" ::)
 443         #define IRQ_ENABLE    asm volatile ("sei" ::)
 444
 445         #define IRQ_SAVE_DISABLE(x) \
 446         do { \
 447                 __asm__ __volatile__( \
 448                         "in %0,__SREG__\n\t" \
 449                         "cli" \
 450                         : "=r" (x) : /* no inputs */ : "cc" \
 451                 ); \
 452         } while (0)
 453
 454         #define IRQ_RESTORE(x) \
 455         do { \
 456                 __asm__ __volatile__( \
 457                         "out __SREG__,%0" : /* no outputs */ : "r" (x) : "cc" \
 458                 ); \
 459         } while (0)
 460
 461         #define IRQ_ENABLED() \
 462         ({ \
 463                 uint8_t sreg; \
 464                 __asm__ __volatile__( \
 465                         "in %0,__SREG__\n\t" \
 466                         : "=r" (sreg)  /* no inputs & no clobbers */ \
 467                 ); \
 468                 (bool)(sreg & 0x80); \
 469         })
 470         #if CONFIG_KERN_PREEMPT
 471                 #define DECLARE_ISR_CONTEXT_SWITCH(vect)                \
 472                         INLINE void __isr_##vect(void);                 \
 473                         ISR(vect)                                       \
 474                         {                                               \
 475                                 __isr_##vect();                         \
 476                                 IRQ_PREEMPT_HANDLER();                  \
 477                         }                                               \
 478                         INLINE void __isr_##vect(void)
 479
 480                 /**
 481                  * With task priorities enabled each ISR is used a point to
 482                  * check if we need to perform a context switch.
 483                  *
 484                  * Instead, without priorities a context switch can occur only
 485                  * when the running task expires its time quantum. In this last
 486                  * case, the context switch can only occur in the timer ISR,
 487                  * that must be always declared with the
 488                  * DECLARE_ISR_CONTEXT_SWITCH() macro.
 489                  */
 490                 #if CONFIG_KERN_PRI
 491                         #define DECLARE_ISR(func) \
 492                                 DECLARE_ISR_CONTEXT_SWITCH(func)
 493                         /**
 494                          * Interrupt service routine prototype: can be used for
 495                          * forward declarations.
 496                          */
 497                         #define ISR_PROTO(func) \
 498                                 ISR_PROTO_CONTEXT_SWITCH(func)
 499                 #endif /* !CONFIG_KERN_PRI */
 500         #endif
 501
 502         #ifndef ISR_PROTO
 503                 #define ISR_PROTO(vect) ISR(vect)
 504         #endif
 505         #ifndef DECLARE_ISR
 506                 #define DECLARE_ISR(vect) ISR(vect)
 507         #endif
 508         #ifndef DECLARE_ISR_CONTEXT_SWITCH
 509                 #define DECLARE_ISR_CONTEXT_SWITCH(vect) ISR(vect)
 510         #endif
 511         #ifndef ISR_PROTO_CONTEXT_SWITCH
 512                 #define ISR_PROTO_CONTEXT_SWITCH(vect) ISR(vect)
 513         #endif
 514
 515 #else
 516         #error No CPU_... defined.
 517 #endif
 518
 519 #ifdef IRQ_RUNNING
 520         /// Ensure callee is running within an interrupt
 521         #define ASSERT_IRQ_CONTEXT()  ASSERT(IRQ_RUNNING())
 522
 523         /// Ensure callee is not running within an interrupt
 524         #define ASSERT_USER_CONTEXT() ASSERT(!IRQ_RUNNING())
 525 #else
 526         #define IRQ_RUNNING()   false
 527         #define ASSERT_USER_CONTEXT()  do {} while(0)
 528         #define ASSERT_IRQ_CONTEXT()   do {} while(0)
 529 #endif
 530
 531 #ifdef IRQ_ENABLED
 532         /// Ensure interrupts are enabled
 533         #define IRQ_ASSERT_ENABLED()  ASSERT(IRQ_ENABLED())
 534
 535         /// Ensure interrupts are not enabled
 536         #define IRQ_ASSERT_DISABLED() ASSERT(!IRQ_ENABLED())
 537 #else
 538         #define IRQ_ASSERT_ENABLED() do {} while(0)
 539         #define IRQ_ASSERT_DISABLED() do {} while(0)
 540 #endif
 541
 542
 543 #ifndef IRQ_PREEMPT_HANDLER
 544         #if CONFIG_KERN_PREEMPT
 545                 /**
 546                  * Handle preemptive context switch inside timer IRQ.
 547                  */
 548                 INLINE void IRQ_PREEMPT_HANDLER(void)
 549                 {
 550                         if (proc_needPreempt())
 551                                 proc_preempt();
 552                 }
 553         #else
 554                 #define IRQ_PREEMPT_HANDLER() /* Nothing */
 555         #endif
 556 #endif
 557
 558 /**
 559  * Execute \a CODE atomically with respect to interrupts.
 560  *
 561  * \see IRQ_SAVE_DISABLE IRQ_RESTORE
 562  */
 563 #define ATOMIC(CODE) \
 564         do { \
 565                 cpu_flags_t __flags; \
 566                 IRQ_SAVE_DISABLE(__flags); \
 567                 CODE; \
 568                 IRQ_RESTORE(__flags); \
 569         } while (0)
 570
 571 #endif /* CPU_IRQ_H */