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                         cpu_flags_t sreg;                               \
 245                         asm volatile (                                  \
 246                                 "mrs %0, cpsr\n\t"                      \
 247                                 "orr %0, %0, #0xc0\n\t"                 \
 248                                 "msr cpsr_c, %0\n\t"                    \
 249                                 : "=r" (sreg) : : "memory", "cc");      \
 250                 } while (0)
 251
 252                 #define IRQ_ENABLE                                      \
 253                 do {                                                    \
 254                         cpu_flags_t sreg;                               \
 255                         asm volatile (                                  \
 256                                 "mrs %0, cpsr\n\t"                      \
 257                                 "bic %0, %0, #0xc0\n\t"                 \
 258                                 "msr cpsr_c, %0\n\t"                    \
 259                                 : "=r" (sreg) : : "memory", "cc");      \
 260                 } while (0)
 261
 262                 #define IRQ_SAVE_DISABLE(x)                             \
 263                 do {                                                    \
 264                         cpu_flags_t sreg;                               \
 265                         (void) (&sreg == &x);                           \
 266                         asm volatile (                                  \
 267                                 "mrs %0, cpsr\n\t"                      \
 268                                 "orr %1, %0, #0xc0\n\t"                 \
 269                                 "msr cpsr_c, %1\n\t"                    \
 270                                 : "=r" (x), "=r" (sreg)                 \
 271                                 : : "memory", "cc");                    \
 272                 } while (0)
 273
 274                 #define IRQ_RESTORE(x)                                  \
 275                 do {                                                    \
 276                         asm volatile (                                  \
 277                                 "msr cpsr_c, %0\n\t"                    \
 278                                 : : "r" (x) : "memory", "cc");          \
 279                 } while (0)
 280
 281                 #define CPU_READ_FLAGS()                                \
 282                 ({                                                      \
 283                         cpu_flags_t sreg;                               \
 284                         asm volatile (                                  \
 285                                 "mrs %0, cpsr\n\t"                      \
 286                                 : "=r" (sreg) : : "memory", "cc");      \
 287                         sreg;                                           \
 288                 })
 289
 290                 #define IRQ_ENABLED() (!(CPU_READ_FLAGS() & 0x80))
 291
 292                 #if CONFIG_KERN_PREEMPT
 293                         EXTERN_C void asm_irq_switch_context(void);
 294
 295                         /**
 296                          * At the beginning of any ISR immediately ajust the
 297                          * return address and store all the caller-save
 298                          * registers (the ISR may change these registers that
 299                          * are shared with the user-context).
 300                          */
 301                         #define IRQ_ENTRY() asm volatile ( \
 302                                                 "sub    lr, lr, #4\n\t" \
 303                                                 "stmfd  sp!, {r0-r3, ip, lr}\n\t")
 304                         #define IRQ_EXIT()  asm volatile ( \
 305                                                 "b      asm_irq_switch_context\n\t")
 306                         /**
 307                          * Function attribute to declare an interrupt service
 308                          * routine.
 309                          *
 310                          * An ISR function must be declared as naked because we
 311                          * want to add our IRQ_ENTRY() prologue and IRQ_EXIT()
 312                          * epilogue code to handle the context switch and save
 313                          * all the registers (not only the callee-save).
 314                          *
 315                          */
 316                         #define ISR_FUNC __attribute__((naked))
 317
 318                         /**
 319                          * The compiler cannot establish which
 320                          * registers actually need to be saved, because
 321                          * the interrupt can happen at any time, so the
 322                          * "normal" prologue and epilogue used for a
 323                          * generic function call are not suitable for
 324                          * the ISR.
 325                          *
 326                          * Using a naked function has the drawback that
 327                          * the stack is not automatically adjusted at
 328                          * this point, like a "normal" function call.
 329                          *
 330                          * So, an ISR can _only_ contain other function
 331                          * calls and they can't use the stack in any
 332                          * other way.
 333                          *
 334                          * NOTE: we need to explicitly disable IRQs after
 335                          * IRQ_ENTRY(), because the IRQ status flag is not
 336                          * masked by the hardware and an IRQ ack inside the ISR
 337                          * may cause the triggering of another IRQ before
 338                          * exiting from the current ISR.
 339                          *
 340                          * The respective IRQ_ENABLE is not necessary, because
 341                          * IRQs will be automatically re-enabled when restoring
 342                          * the context of the user task.
 343                          */
 344                         #define DECLARE_ISR_CONTEXT_SWITCH(func)        \
 345                                 void ISR_FUNC func(void);               \
 346                                 static void __isr_##func(void);         \
 347                                 void ISR_FUNC func(void)                \
 348                                 {                                       \
 349                                         IRQ_ENTRY();                    \
 350                                         IRQ_DISABLE;                    \
 351                                         __isr_##func();                 \
 352                                         IRQ_EXIT();                     \
 353                                 }                                       \
 354                                 static void __isr_##func(void)
 355                         /**
 356                          * Interrupt service routine prototype: can be used for
 357                          * forward declarations.
 358                          */
 359                         #define ISR_PROTO_CONTEXT_SWITCH(func)  \
 360                                 void ISR_FUNC func(void)
 361                         /**
 362                          * With task priorities enabled each ISR is used a point to
 363                          * check if we need to perform a context switch.
 364                          *
 365                          * Instead, without priorities a context switch can occur only
 366                          * when the running task expires its time quantum. In this last
 367                          * case, the context switch can only occur in the timer
 368                          * ISR, that must be always declared with the
 369                          * DECLARE_ISR_CONTEXT_SWITCH() macro.
 370                          */
 371                         #if CONFIG_KERN_PRI
 372                                 #define DECLARE_ISR(func) \
 373                                         DECLARE_ISR_CONTEXT_SWITCH(func)
 374
 375                                 #define ISR_PROTO(func) \
 376                                         ISR_PROTO_CONTEXT_SWITCH(func)
 377                         #endif /* !CONFIG_KERN_PRI */
 378                 #endif /* CONFIG_KERN_PREEMPT */
 379
 380                 #ifndef DECLARE_ISR
 381                         #define DECLARE_ISR(func) \
 382                                 void __attribute__((interrupt)) func(void)
 383                 #endif
 384                 #ifndef DECLARE_ISR_CONTEXT_SWITCH
 385                         #define DECLARE_ISR_CONTEXT_SWITCH(func) \
 386                                 void __attribute__((interrupt)) func(void)
 387                 #endif
 388                 #ifndef ISR_PROTO
 389                         #define ISR_PROTO(func) \
 390                                 void __attribute__((interrupt)) func(void)
 391                 #endif
 392                 #ifndef ISR_PROTO_CONTEXT_SWITCH
 393                         #define ISR_PROTO_CONTEXT_SWITCH(func)  \
 394                                 void __attribute__((interrupt)) func(void)
 395                 #endif
 396
 397         #endif /* !__IAR_SYSTEMS_ICC_ */
 398
 399 #elif CPU_PPC
 400
 401         /* Get IRQ_* definitions from the hosting environment. */
 402         #include <cfg/os.h>
 403         #if OS_EMBEDDED
 404                 #define IRQ_DISABLE         FIXME
 405                 #define IRQ_ENABLE          FIXME
 406                 #define IRQ_SAVE_DISABLE(x) FIXME
 407                 #define IRQ_RESTORE(x)      FIXME
 408                 #define IRQ_ENABLED()       FIXME
 409         #endif /* OS_EMBEDDED */
 410
 411 #elif CPU_DSP56K
 412
 413         #define IRQ_DISABLE             do { asm(bfset #0x0200,SR); asm(nop); } while (0)
 414         #define IRQ_ENABLE              do { asm(bfclr #0x0200,SR); asm(nop); } while (0)
 415
 416         #define IRQ_SAVE_DISABLE(x)  \
 417                 do { (void)x; asm(move SR,x); asm(bfset #0x0200,SR); } while (0)
 418         #define IRQ_RESTORE(x)  \
 419                 do { (void)x; asm(move x,SR); } while (0)
 420
 421         static inline bool irq_running(void)
 422         {
 423                 extern void *user_sp;
 424                 return !!user_sp;
 425         }
 426         #define IRQ_RUNNING() irq_running()
 427
 428         static inline bool irq_enabled(void)
 429         {
 430                 uint16_t x;
 431                 asm(move SR,x);
 432                 return !(x & 0x0200);
 433         }
 434         #define IRQ_ENABLED() irq_enabled()
 435
 436 #elif CPU_AVR
 437
 438         #define IRQ_DISABLE   asm volatile ("cli" ::)
 439         #define IRQ_ENABLE    asm volatile ("sei" ::)
 440
 441         #define IRQ_SAVE_DISABLE(x) \
 442         do { \
 443                 __asm__ __volatile__( \
 444                         "in %0,__SREG__\n\t" \
 445                         "cli" \
 446                         : "=r" (x) : /* no inputs */ : "cc" \
 447                 ); \
 448         } while (0)
 449
 450         #define IRQ_RESTORE(x) \
 451         do { \
 452                 __asm__ __volatile__( \
 453                         "out __SREG__,%0" : /* no outputs */ : "r" (x) : "cc" \
 454                 ); \
 455         } while (0)
 456
 457         #define IRQ_ENABLED() \
 458         ({ \
 459                 uint8_t sreg; \
 460                 __asm__ __volatile__( \
 461                         "in %0,__SREG__\n\t" \
 462                         : "=r" (sreg)  /* no inputs & no clobbers */ \
 463                 ); \
 464                 (bool)(sreg & 0x80); \
 465         })
 466         #if CONFIG_KERN_PREEMPT
 467                 #define DECLARE_ISR_CONTEXT_SWITCH(vect)                \
 468                         INLINE void __isr_##vect(void);                 \
 469                         ISR(vect)                                       \
 470                         {                                               \
 471                                 __isr_##vect();                         \
 472                                 IRQ_PREEMPT_HANDLER();                  \
 473                         }                                               \
 474                         INLINE void __isr_##vect(void)
 475
 476                 /**
 477                  * With task priorities enabled each ISR is used a point to
 478                  * check if we need to perform a context switch.
 479                  *
 480                  * Instead, without priorities a context switch can occur only
 481                  * when the running task expires its time quantum. In this last
 482                  * case, the context switch can only occur in the timer ISR,
 483                  * that must be always declared with the
 484                  * DECLARE_ISR_CONTEXT_SWITCH() macro.
 485                  */
 486                 #if CONFIG_KERN_PRI
 487                         #define DECLARE_ISR(func) \
 488                                 DECLARE_ISR_CONTEXT_SWITCH(func)
 489                         /**
 490                          * Interrupt service routine prototype: can be used for
 491                          * forward declarations.
 492                          */
 493                         #define ISR_PROTO(func) \
 494                                 ISR_PROTO_CONTEXT_SWITCH(func)
 495                 #endif /* !CONFIG_KERN_PRI */
 496         #endif
 497
 498         #ifndef ISR_PROTO
 499                 #define ISR_PROTO(vect) ISR(vect)
 500         #endif
 501         #ifndef DECLARE_ISR
 502                 #define DECLARE_ISR(vect) ISR(vect)
 503         #endif
 504         #ifndef DECLARE_ISR_CONTEXT_SWITCH
 505                 #define DECLARE_ISR_CONTEXT_SWITCH(vect) ISR(vect)
 506         #endif
 507         #ifndef ISR_PROTO_CONTEXT_SWITCH
 508                 #define ISR_PROTO_CONTEXT_SWITCH(vect) ISR(vect)
 509         #endif
 510
 511 #else
 512         #error No CPU_... defined.
 513 #endif
 514
 515 #ifdef IRQ_RUNNING
 516         /// Ensure callee is running within an interrupt
 517         #define ASSERT_IRQ_CONTEXT()  ASSERT(IRQ_RUNNING())
 518
 519         /// Ensure callee is not running within an interrupt
 520         #define ASSERT_USER_CONTEXT() ASSERT(!IRQ_RUNNING())
 521 #else
 522         #define IRQ_RUNNING()   false
 523         #define ASSERT_USER_CONTEXT()  do {} while(0)
 524         #define ASSERT_IRQ_CONTEXT()   do {} while(0)
 525 #endif
 526
 527 #ifdef IRQ_ENABLED
 528         /// Ensure interrupts are enabled
 529         #define IRQ_ASSERT_ENABLED()  ASSERT(IRQ_ENABLED())
 530
 531         /// Ensure interrupts are not enabled
 532         #define IRQ_ASSERT_DISABLED() ASSERT(!IRQ_ENABLED())
 533 #else
 534         #define IRQ_ASSERT_ENABLED() do {} while(0)
 535         #define IRQ_ASSERT_DISABLED() do {} while(0)
 536 #endif
 537
 538
 539 #ifndef IRQ_PREEMPT_HANDLER
 540         #if CONFIG_KERN_PREEMPT
 541                 /**
 542                  * Handle preemptive context switch inside timer IRQ.
 543                  */
 544                 INLINE void IRQ_PREEMPT_HANDLER(void)
 545                 {
 546                         if (proc_needPreempt())
 547                                 proc_preempt();
 548                 }
 549         #else
 550                 #define IRQ_PREEMPT_HANDLER() /* Nothing */
 551         #endif
 552 #endif
 553
 554 /**
 555  * Execute \a CODE atomically with respect to interrupts.
 556  *
 557  * \see IRQ_SAVE_DISABLE IRQ_RESTORE
 558  */
 559 #define ATOMIC(CODE) \
 560         do { \
 561                 cpu_flags_t __flags; \
 562                 IRQ_SAVE_DISABLE(__flags); \
 563                 CODE; \
 564                 IRQ_RESTORE(__flags); \
 565         } while (0)
 566
 567 #endif /* CPU_IRQ_H */