Changeset 2086948a in rtems

Timestamp:

May 11, 2018, 4:54:59 AM (2 years ago)

Author:

Sebastian Huber <sebastian.huber@…>

Branches:

5, master

Children:

fe2cd01b

Parents:

853c5ef

git-author:

Sebastian Huber <sebastian.huber@…> (05/11/18 04:54:59)

git-committer:

Sebastian Huber <sebastian.huber@…> (06/28/18 13:02:12)

Message:

riscv: Add dummy SMP support

Update #3433.

Files:

• bsps/riscv/riscv/start/start.S (modified) (2 diffs)
• c/src/lib/libbsp/riscv/riscv/Makefile.am (modified) (1 diff)
• cpukit/score/cpu/riscv/include/rtems/score/cpu.h (modified) (5 diffs)
• cpukit/score/cpu/riscv/include/rtems/score/cpuimpl.h (modified) (2 diffs)
• testsuites/smptests/smpfatal08/init.c (modified) (1 diff)

bsps/riscv/riscv/start/start.S

@@ -53 +53 @@
         .option pop
 
+#ifdef RTEMS_SMP
+        csrr    s0, mhartid
+        bnez    s0, .Lloop_forever
+#endif
+
         la      t0, ISR_Handler
         csrw    mtvec, t0
@@ -70 +75 @@
 
         j       boot_card
+
+#ifdef RTEMS_SMP
+.Lloop_forever:
+        j       .Lloop_forever
+#endif
 
         .align  4

c/src/lib/libbsp/riscv/riscv/Makefile.am

@@ -62 +62 @@
 librtemsbsp_a_SOURCES += ../../../../../../bsps/riscv/riscv/console/console-io.c
 
+if HAS_SMP
+librtemsbsp_a_SOURCES += ../../../../../../bsps/shared/start/bspsmp-dummy.c
+endif
 
 include $(top_srcdir)/../../../../automake/local.am

cpukit/score/cpu/riscv/include/rtems/score/cpu.h

@@ -81 +81 @@
   unsigned long mepc;
 #ifdef RTEMS_SMP
-  /**
-   * @brief On SMP configurations the thread context must contain a boolean
-   * indicator to signal if this context is executing on a processor.
-   *
-   * This field must be updated during a context switch.  The context switch
-   * to the heir must wait until the heir context indicates that it is no
-   * longer executing on a processor.  The context switch must also check if
-   * a thread dispatch is necessary to honor updates of the heir thread for
-   * this processor.  This indicator must be updated using an atomic test and
-   * set operation to ensure that at most one processor uses the heir
-   * context at the same time.
-   *
-   * @code
-   * void _CPU_Context_switch(
-   *   Context_Control *executing,
-   *   Context_Control *heir
-   * )
-   * {
-   *   save( executing );
-   *
-   *   executing->is_executing = false;
-   *   memory_barrier();
-   *
-   *   if ( test_and_set( &heir->is_executing ) ) {
-   *     do {
-   *       Per_CPU_Control *cpu_self = _Per_CPU_Get_snapshot();
-   *
-   *       if ( cpu_self->dispatch_necessary ) {
-   *         heir = _Thread_Get_heir_and_make_it_executing( cpu_self );
-   *       }
-   *     } while ( test_and_set( &heir->is_executing ) );
-   *   }
-   *
-   *   restore( heir );
-   * }
-   * @endcode
-   */
   volatile bool is_executing;
 #endif
@@ -481 +444 @@
 
 #ifdef RTEMS_SMP
-/**
- * @brief Performs CPU specific SMP initialization in the context of the boot
- * processor.
- *
- * This function is invoked on the boot processor during system
- * initialization.  All interrupt stacks are allocated at this point in case
- * the CPU port allocates the interrupt stacks.  This function is called
- * before _CPU_SMP_Start_processor() or _CPU_SMP_Finalize_initialization() is
- * used.
- *
- * @return The count of physically or virtually available processors.
- * Depending on the configuration the application may use not all processors.
- */
+
 uint32_t _CPU_SMP_Initialize( void );
 
-/**
- * @brief Starts a processor specified by its index.
- *
- * This function is invoked on the boot processor during system
- * initialization.
- *
- * This function will be called after _CPU_SMP_Initialize().
- *
- * @param[in] cpu_index The processor index.
- *
- * @retval true Successful operation.
- * @retval false Unable to start this processor.
- */
 bool _CPU_SMP_Start_processor( uint32_t cpu_index );
 
-/**
- * @brief Performs final steps of CPU specific SMP initialization in the
- * context of the boot processor.
- *
- * This function is invoked on the boot processor during system
- * initialization.
- *
- * This function will be called after all processors requested by the
- * application have been started.
- *
- * @param[in] cpu_count The minimum value of the count of processors
- * requested by the application configuration and the count of physically or
- * virtually available processors.
- */
 void _CPU_SMP_Finalize_initialization( uint32_t cpu_count );
 
-/**
- * @brief Returns the index of the current processor.
- *
- * An architecture specific method must be used to obtain the index of the
- * current processor in the system.  The set of processor indices is the
- * range of integers starting with zero up to the processor count minus one.
- */
-uint32_t _CPU_SMP_Get_current_processor( void );
-
-/**
- * @brief Sends an inter-processor interrupt to the specified target
- * processor.
- *
- * This operation is undefined for target processor indices out of range.
- *
- * @param[in] target_processor_index The target processor index.
- */
+void _CPU_SMP_Prepare_start_multitasking( void );
+
+static inline uint32_t _CPU_SMP_Get_current_processor( void )
+{
+  unsigned long mhartid;
+
+  __asm__ volatile ( "csrr %0, mhartid" : "=&r" ( mhartid ) );
+
+  return (uint32_t) mhartid;
+}
+
 void _CPU_SMP_Send_interrupt( uint32_t target_processor_index );
 
-/**
- * @brief Broadcasts a processor event.
- *
- * Some architectures provide a low-level synchronization primitive for
- * processors in a multi-processor environment.  Processors waiting for this
- * event may go into a low-power state and stop generating system bus
- * transactions.  This function must ensure that preceding store operations
- * can be observed by other processors.
- *
- * @see _CPU_SMP_Processor_event_receive().
- */
-void _CPU_SMP_Processor_event_broadcast( void );
-
-/**
- * @brief Receives a processor event.
- *
- * This function will wait for the processor event and may wait forever if no
- * such event arrives.
- *
- * @see _CPU_SMP_Processor_event_broadcast().
- */
+static inline void _CPU_SMP_Processor_event_broadcast( void )
+{
+  __asm__ volatile ( "" : : : "memory" );
+}
+
 static inline void _CPU_SMP_Processor_event_receive( void )
 {
@@ -572 +474 @@
 }
 
-/**
- * @brief Gets the is executing indicator of the thread context.
- *
- * @param[in] context The context.
- */
 static inline bool _CPU_Context_Get_is_executing(
   const Context_Control *context
@@ -584 +481 @@
 }
 
-/**
- * @brief Sets the is executing indicator of the thread context.
- *
- * @param[in] context The context.
- * @param[in] is_executing The new value for the is executing indicator.
- */
 static inline void _CPU_Context_Set_is_executing(
   Context_Control *context,
@@ -597 +488 @@
   context->is_executing = is_executing;
 }
+
 #endif /* RTEMS_SMP */
 

cpukit/score/cpu/riscv/include/rtems/score/cpuimpl.h

@@ -6 +6 @@
 
 /*
- * Copyright (c) 2013 embedded brains GmbH
+ * Copyright (c) 2013, 2018 embedded brains GmbH
  *
  * Redistribution and use in source and binary forms, with or without
@@ -37 +37 @@
 #define CPU_PER_CPU_CONTROL_SIZE 0
 
+#if __riscv_xlen == 32
+
+#define CPU_INTERRUPT_FRAME_SIZE 144
+
+#elif __riscv_xlen == 64
+
+#define CPU_INTERRUPT_FRAME_SIZE 288
+
+#endif /* __riscv_xlen */
+
 #ifndef ASM
 

testsuites/smptests/smpfatal08/init.c

@@ -72 +72 @@
 
 #if defined(RTEMS_PARAVIRT) \
-  || (!defined(__leon__) && !defined(__PPC__) && !defined(__arm__))
+  || (!defined(__leon__) && !defined(__PPC__) \
+    && !defined(__arm__) && !defined(__riscv))
 uint32_t _CPU_SMP_Get_current_processor(void)
 {