[PATCH 10/10] sparc: Simplify trap table initialization

Gedare Bloom gedare at rtems.org
Wed Jun 23 20:42:20 UTC 2021


This patch set looks ok, but it touches a lot of assembly. Try to
ensure all variants have been thoroughly tested, including the
different ways to setup the FPU on sparc (lazy, hard/soft), with SMP,
and Profiling.

On Wed, Jun 23, 2021 at 12:50 AM Sebastian Huber
<sebastian.huber at embedded-brains.de> wrote:
>
> Move _ISR_Handler() to a separate file since it is now only used if a handler
> is installed by _CPU_ISR_install_raw_handler().
>
> Statically initialize the traps for external interrupts to use the new
> _SPARC_Interrupt_trap() which directly dispatches the interrupt handlers
> installed by rtems_interrupt_handler_install() via the BSP-provided
> _SPARC_Interrupt_dispatch().
>
> Since the trap table is now fully statically initialized, there is no longer a
> dependency on the Cache Manager in the default configuration.
>
> Update #4458.
> ---
>  bsps/sparc/erc32/include/bsp.h                |   6 -
>  bsps/sparc/erc32/start/bspstart.c             |  15 +-
>  bsps/sparc/leon2/include/bsp.h                |   6 -
>  bsps/sparc/leon2/start/bspstart.c             |   2 +-
>  bsps/sparc/leon3/include/bsp.h                |   6 -
>  bsps/sparc/leon3/start/bspsmp.c               |  24 +-
>  bsps/sparc/leon3/start/bspstart.c             |  34 +-
>  bsps/sparc/shared/irq/bsp_isr_handler.c       |  27 +-
>  bsps/sparc/shared/irq/irq-shared.c            |  21 -
>  bsps/sparc/shared/start/start.S               |  39 +-
>  cpukit/Makefile.am                            |   1 +
>  cpukit/score/cpu/sparc/cpu_asm.S              |  64 +-
>  .../score/cpu/sparc/include/rtems/score/cpu.h |   8 +-
>  cpukit/score/cpu/sparc/sparc-isr-handler.S    | 620 ++++++++++++++++++
>  spec/build/cpukit/cpusparc.yml                |   1 +
>  15 files changed, 704 insertions(+), 170 deletions(-)
>  create mode 100644 cpukit/score/cpu/sparc/sparc-isr-handler.S
>
> diff --git a/bsps/sparc/erc32/include/bsp.h b/bsps/sparc/erc32/include/bsp.h
> index 7fb2fa9d72..fd453fb6c2 100644
> --- a/bsps/sparc/erc32/include/bsp.h
> +++ b/bsps/sparc/erc32/include/bsp.h
> @@ -95,12 +95,6 @@ void BSP_fatal_exit(uint32_t error);
>  /* Interrupt Service Routine (ISR) pointer */
>  typedef void (*bsp_shared_isr)(void *arg);
>
> -/* Initializes the Shared System Interrupt service */
> -extern void BSP_shared_interrupt_init(void);
> -
> -/* Called directly from IRQ trap handler TRAP[0x10..0x1F] = IRQ[0..15] */
> -void bsp_isr_handler(rtems_vector_number vector);
> -
>  /* Registers a shared IRQ handler, and enable it at IRQ controller. Multiple
>   * interrupt handlers may use the same IRQ number, all ISRs will be called
>   * when an interrupt on that line is fired.
> diff --git a/bsps/sparc/erc32/start/bspstart.c b/bsps/sparc/erc32/start/bspstart.c
> index d56d3b2ff2..1979c68308 100644
> --- a/bsps/sparc/erc32/start/bspstart.c
> +++ b/bsps/sparc/erc32/start/bspstart.c
> @@ -12,22 +12,15 @@
>
>  #include <bsp.h>
>  #include <bsp/bootcard.h>
> +#include <bsp/irq-generic.h>
>  #include <rtems/sysinit.h>
>
>  /*
> - * Called just before drivers are initialized.  Is used to initialize shared
> - * interrupt handling.
> + * Initialize shared interrupt handling, must be done after IRQ controller has
> + * been found and initialized.
>   */
> -static void erc32_pre_driver_hook( void )
> -{
> -  /* Initialize shared interrupt handling, must be done after IRQ
> -   * controller has been found and initialized.
> -   */
> -  BSP_shared_interrupt_init();
> -}
> -
>  RTEMS_SYSINIT_ITEM(
> -  erc32_pre_driver_hook,
> +  bsp_interrupt_initialize,
>    RTEMS_SYSINIT_BSP_PRE_DRIVERS,
>    RTEMS_SYSINIT_ORDER_MIDDLE
>  );
> diff --git a/bsps/sparc/leon2/include/bsp.h b/bsps/sparc/leon2/include/bsp.h
> index bdd9c1ca70..510262206b 100644
> --- a/bsps/sparc/leon2/include/bsp.h
> +++ b/bsps/sparc/leon2/include/bsp.h
> @@ -119,12 +119,6 @@ void BSP_fatal_exit(uint32_t error);
>  /* Interrupt Service Routine (ISR) pointer */
>  typedef void (*bsp_shared_isr)(void *arg);
>
> -/* Initializes the Shared System Interrupt service */
> -extern void BSP_shared_interrupt_init(void);
> -
> -/* Called directly from IRQ trap handler TRAP[0x10..0x1F] = IRQ[0..15] */
> -void bsp_isr_handler(rtems_vector_number vector);
> -
>  /* Registers a shared IRQ handler, and enable it at IRQ controller. Multiple
>   * interrupt handlers may use the same IRQ number, all ISRs will be called
>   * when an interrupt on that line is fired.
> diff --git a/bsps/sparc/leon2/start/bspstart.c b/bsps/sparc/leon2/start/bspstart.c
> index 8ffd0aa2e7..e90cfad5a8 100644
> --- a/bsps/sparc/leon2/start/bspstart.c
> +++ b/bsps/sparc/leon2/start/bspstart.c
> @@ -111,7 +111,7 @@ static void leon2_pre_driver_hook( void )
>    /* Initialize shared interrupt handling, must be done after IRQ
>     * controller has been found and initialized.
>     */
> -  BSP_shared_interrupt_init();
> +  bsp_interrupt_initialize();
>
>  #ifdef RTEMS_DRVMGR_STARTUP
>    leon2_root_register(&leon2_bus_config, &leon2_amba_res);
> diff --git a/bsps/sparc/leon3/include/bsp.h b/bsps/sparc/leon3/include/bsp.h
> index 82f1f9f8ac..cb08764eae 100644
> --- a/bsps/sparc/leon3/include/bsp.h
> +++ b/bsps/sparc/leon3/include/bsp.h
> @@ -139,12 +139,6 @@ void rtems_bsp_delay(int usecs);
>  /* Interrupt Service Routine (ISR) pointer */
>  typedef void (*bsp_shared_isr)(void *arg);
>
> -/* Initializes the Shared System Interrupt service */
> -extern void BSP_shared_interrupt_init(void);
> -
> -/* Called directly from IRQ trap handler TRAP[0x10..0x1F] = IRQ[0..15] */
> -void bsp_isr_handler(rtems_vector_number vector);
> -
>  /* Registers a shared IRQ handler, and enable it at IRQ controller. Multiple
>   * interrupt handlers may use the same IRQ number, all ISRs will be called
>   * when an interrupt on that line is fired.
> diff --git a/bsps/sparc/leon3/start/bspsmp.c b/bsps/sparc/leon3/start/bspsmp.c
> index c73c3fd5d0..f2749bfa06 100644
> --- a/bsps/sparc/leon3/start/bspsmp.c
> +++ b/bsps/sparc/leon3/start/bspsmp.c
> @@ -18,6 +18,7 @@
>  #include <bsp/fatal.h>
>  #include <leon.h>
>  #include <rtems/bspIo.h>
> +#include <rtems/sysinit.h>
>  #include <rtems/score/assert.h>
>  #include <rtems/score/smpimpl.h>
>  #include <stdlib.h>
> @@ -55,13 +56,10 @@ void bsp_start_on_secondary_processor(Per_CPU_Control *cpu_self)
>    _SMP_Start_multitasking_on_secondary_processor(cpu_self);
>  }
>
> -uint32_t _CPU_SMP_Initialize( void )
> +static void leon3_install_inter_processor_interrupt( void )
>  {
>    rtems_status_code sc;
>
> -  if ( !leon3_data_cache_snooping_enabled() )
> -    bsp_fatal( LEON3_FATAL_INVALID_CACHE_CONFIG_MAIN_PROCESSOR );
> -
>    sc = rtems_interrupt_handler_install(
>      LEON3_mp_irq,
>      "IPI",
> @@ -70,6 +68,16 @@ uint32_t _CPU_SMP_Initialize( void )
>      NULL
>    );
>    _Assert_Unused_variable_equals( sc, RTEMS_SUCCESSFUL );
> +}
> +
> +uint32_t _CPU_SMP_Initialize( void )
> +{
> +  if ( !leon3_data_cache_snooping_enabled() )
> +    bsp_fatal( LEON3_FATAL_INVALID_CACHE_CONFIG_MAIN_PROCESSOR );
> +
> +#if !defined(RTEMS_DRVMGR_STARTUP)
> +  leon3_install_inter_processor_interrupt();
> +#endif
>
>    return leon3_get_cpu_count(LEON3_IrqCtrl_Regs);
>  }
> @@ -102,3 +110,11 @@ void _CPU_SMP_Send_interrupt(uint32_t target_processor_index)
>    /* send interrupt to destination CPU */
>    LEON3_IrqCtrl_Regs->force[target_processor_index] = 1 << LEON3_mp_irq;
>  }
> +
> +#if defined(RTEMS_DRVMGR_STARTUP)
> +RTEMS_SYSINIT_ITEM(
> +  leon3_install_inter_processor_interrupt,
> +  RTEMS_SYSINIT_DRVMGR_LEVEL_1,
> +  RTEMS_SYSINIT_ORDER_LAST_BUT_4
> +);
> +#endif
> diff --git a/bsps/sparc/leon3/start/bspstart.c b/bsps/sparc/leon3/start/bspstart.c
> index 69ff519189..75042e4c20 100644
> --- a/bsps/sparc/leon3/start/bspstart.c
> +++ b/bsps/sparc/leon3/start/bspstart.c
> @@ -20,6 +20,7 @@
>   */
>
>  #include <bsp.h>
> +#include <bsp/irq-generic.h>
>  #include <leon.h>
>  #include <bsp/bootcard.h>
>  #include <rtems/sysinit.h>
> @@ -66,6 +67,10 @@ static inline int set_snooping(void)
>  void bsp_start( void )
>  {
>    CPU_SPARC_HAS_SNOOPING = set_snooping();
> +
> +#ifndef RTEMS_DRVMGR_STARTUP
> +  bsp_interrupt_initialize();
> +#endif
>  }
>
>  static void leon3_cpu_index_init(void)
> @@ -84,38 +89,13 @@ RTEMS_SYSINIT_ITEM(
>    RTEMS_SYSINIT_ORDER_FIRST
>  );
>
> -static void leon3_interrupt_common_init( void )
> -{
> -  /* Initialize shared interrupt handling, must be done after IRQ
> -   * controller has been found and initialized.
> -   */
> -  BSP_shared_interrupt_init();
> -}
> -
> -/*
> - * Called just before drivers are initialized.  Is used to initialize shared
> - * interrupt handling.
> - */
> -static void leon3_pre_driver_hook( void )
> -{
> -#ifndef RTEMS_DRVMGR_STARTUP
> -  leon3_interrupt_common_init();
> -#endif
> -}
> -
> -RTEMS_SYSINIT_ITEM(
> -  leon3_pre_driver_hook,
> -  RTEMS_SYSINIT_BSP_PRE_DRIVERS,
> -  RTEMS_SYSINIT_ORDER_MIDDLE
> -);
> -
> -#ifdef RTEMS_DRVMGR_STARTUP
>  /*
>   * Initialize shared interrupt handling, must be done after IRQ controller has
>   * been found and initialized.
>   */
> +#ifdef RTEMS_DRVMGR_STARTUP
>  RTEMS_SYSINIT_ITEM(
> -  leon3_interrupt_common_init,
> +  bsp_interrupt_initialize,
>    RTEMS_SYSINIT_DRVMGR_LEVEL_1,
>    RTEMS_SYSINIT_ORDER_LAST_BUT_5
>  );
> diff --git a/bsps/sparc/shared/irq/bsp_isr_handler.c b/bsps/sparc/shared/irq/bsp_isr_handler.c
> index a4d33b0932..2616b5caae 100644
> --- a/bsps/sparc/shared/irq/bsp_isr_handler.c
> +++ b/bsps/sparc/shared/irq/bsp_isr_handler.c
> @@ -8,28 +8,19 @@
>  *
>  */
>
> -#include <rtems.h>
>  #include <bsp.h>
>  #include <bsp/irq-generic.h>
>
> -static inline void bsp_dispatch_irq(int irq)
> -{
> -  bsp_interrupt_handler_entry *e =
> -    &bsp_interrupt_handler_table[bsp_interrupt_handler_index(irq)];
> -
> -  while (e != NULL) {
> -    (*e->handler)(e->arg);
> -    e = e->next;
> -  }
> -}
> -
> -/* Called directly from IRQ trap handler TRAP[0x10..0x1F] = IRQ[0..15] */
> -void bsp_isr_handler(rtems_vector_number vector)
> +/*
> + * This function is called directly from _SPARC_Interrupt_trap() for
> + * traps 0x10 to 0x1F which correspond to IRQ 0 to 15 respectively.
> + */
> +void _SPARC_Interrupt_dispatch( uint32_t irq )
>  {
> -  int irq = vector - 0x10;
> +  bsp_interrupt_assert( irq < BSP_INTERRUPT_VECTOR_COUNT );
>
> -  /* Let BSP fixup and/or handle incomming IRQ */
> -  irq = bsp_irq_fixup(irq);
> +  /* Let BSP fixup and/or handle incoming IRQ */
> +  irq = bsp_irq_fixup( irq );
>
> -  bsp_dispatch_irq(irq);
> +  bsp_interrupt_handler_dispatch_unchecked( irq );
>  }
> diff --git a/bsps/sparc/shared/irq/irq-shared.c b/bsps/sparc/shared/irq/irq-shared.c
> index e0ac7d7f06..a127ab64c2 100644
> --- a/bsps/sparc/shared/irq/irq-shared.c
> +++ b/bsps/sparc/shared/irq/irq-shared.c
> @@ -37,27 +37,6 @@ static inline int bsp_irq_cpu(int irq)
>  }
>  #endif
>
> -/* Initialize interrupts */
> -void BSP_shared_interrupt_init(void)
> -{
> -  rtems_vector_number vector;
> -  rtems_isr_entry previous_isr;
> -  int i;
> -
> -  for (i=0; i <= BSP_INTERRUPT_VECTOR_MAX_STD; i++) {
> -#if defined(LEON3) && (defined(RTEMS_SMP) || defined(RTEMS_MULTIPROCESSING))
> -    /* Don't install IRQ handler on IPI interrupt */
> -    if (i == LEON3_mp_irq)
> -      continue;
> -#endif
> -    vector = SPARC_ASYNCHRONOUS_TRAP(i) + 0x10;
> -    rtems_interrupt_catch(bsp_isr_handler, vector, &previous_isr);
> -  }
> -
> -  /* Initalize interrupt support */
> -  bsp_interrupt_initialize();
> -}
> -
>  /* Callback from bsp_interrupt_initialize() */
>  rtems_status_code bsp_interrupt_facility_initialize(void)
>  {
> diff --git a/bsps/sparc/shared/start/start.S b/bsps/sparc/shared/start/start.S
> index cd43f08f01..45bd145d4a 100644
> --- a/bsps/sparc/shared/start/start.S
> +++ b/bsps/sparc/shared/start/start.S
> @@ -32,6 +32,13 @@
>    TRAP_SYM(_vector):; \
>    TRAP(_vector, _SPARC_Bad_trap)
>
> +/*
> + * External interrupt trap
> + */
> +#define ISR_TRAP(_vector) \
> +  TRAP_SYM(_vector):; \
> +  TRAP(_vector - 0x10, _SPARC_Interrupt_trap)
> +
>  /*
>   * System call optimized trap table entry
>   */
> @@ -128,27 +135,27 @@ TRAP_SYM(0x06):
>    BAD_TRAP(0x0d)                                ! 0D undefined
>    BAD_TRAP(0x0e)                                ! 0E undefined
>    BAD_TRAP(0x0f)                                ! 0F undefined
> -  BAD_TRAP(0x10)                                ! 10 undefined
>
>    /*
>     *  External interrupt traps
>     */
>
> -  BAD_TRAP(0x11)                                ! 11 external interrupt 1
> -  BAD_TRAP(0x12)                                ! 12 external interrupt 2
> -  BAD_TRAP(0x13)                                ! 13 external interrupt 3
> -  BAD_TRAP(0x14)                                ! 14 external interrupt 4
> -  BAD_TRAP(0x15)                                ! 15 external interrupt 5
> -  BAD_TRAP(0x16)                                ! 16 external interrupt 6
> -  BAD_TRAP(0x17)                                ! 17 external interrupt 7
> -  BAD_TRAP(0x18)                                ! 18 external interrupt 8
> -  BAD_TRAP(0x19)                                ! 19 external interrupt 9
> -  BAD_TRAP(0x1a)                                ! 1A external interrupt 10
> -  BAD_TRAP(0x1b)                                ! 1B external interrupt 11
> -  BAD_TRAP(0x1c)                                ! 1C external interrupt 12
> -  BAD_TRAP(0x1d)                                ! 1D external interrupt 13
> -  BAD_TRAP(0x1e)                                ! 1E external interrupt 14
> -  BAD_TRAP(0x1f)                                ! 1F external interrupt 15
> +  ISR_TRAP(0x10)                                ! 10 undefined
> +  ISR_TRAP(0x11)                                ! 11 external interrupt 1
> +  ISR_TRAP(0x12)                                ! 12 external interrupt 2
> +  ISR_TRAP(0x13)                                ! 13 external interrupt 3
> +  ISR_TRAP(0x14)                                ! 14 external interrupt 4
> +  ISR_TRAP(0x15)                                ! 15 external interrupt 5
> +  ISR_TRAP(0x16)                                ! 16 external interrupt 6
> +  ISR_TRAP(0x17)                                ! 17 external interrupt 7
> +  ISR_TRAP(0x18)                                ! 18 external interrupt 8
> +  ISR_TRAP(0x19)                                ! 19 external interrupt 9
> +  ISR_TRAP(0x1a)                                ! 1A external interrupt 10
> +  ISR_TRAP(0x1b)                                ! 1B external interrupt 11
> +  ISR_TRAP(0x1c)                                ! 1C external interrupt 12
> +  ISR_TRAP(0x1d)                                ! 1D external interrupt 13
> +  ISR_TRAP(0x1e)                                ! 1E external interrupt 14
> +  ISR_TRAP(0x1f)                                ! 1F external interrupt 15
>
>    BAD_TRAP(0x20)                                ! 20 undefined
>    BAD_TRAP(0x21)                                ! 21 undefined
> diff --git a/cpukit/Makefile.am b/cpukit/Makefile.am
> index 83c14cd2ab..c83167668d 100644
> --- a/cpukit/Makefile.am
> +++ b/cpukit/Makefile.am
> @@ -1623,6 +1623,7 @@ librtemscpu_a_SOURCES += score/cpu/sparc/sparc-context-validate.S
>  librtemscpu_a_SOURCES += score/cpu/sparc/sparc-context-volatile-clobber.S
>  librtemscpu_a_SOURCES += score/cpu/sparc/sparc-counter-asm.S
>  librtemscpu_a_SOURCES += score/cpu/sparc/sparc-exception-frame-print.c
> +librtemscpu_a_SOURCES += score/cpu/sparc/sparc-isr-handler.S
>  librtemscpu_a_SOURCES += score/cpu/sparc/sparc-isr-install.c
>  librtemscpu_a_SOURCES += score/cpu/sparc/syscall.S
>  librtemscpu_a_SOURCES += score/cpu/sparc/window.S
> diff --git a/cpukit/score/cpu/sparc/cpu_asm.S b/cpukit/score/cpu/sparc/cpu_asm.S
> index 16f5c70206..45d1495af7 100644
> --- a/cpukit/score/cpu/sparc/cpu_asm.S
> +++ b/cpukit/score/cpu/sparc/cpu_asm.S
> @@ -295,7 +295,7 @@ SYM(_CPU_Context_restore):
>          mov     %i0, %o1                      ! in the delay slot
>
>  /*
> - *  void _ISR_Handler()
> + *  void _SPARC_Interrupt_trap()
>   *
>   *  This routine provides the RTEMS interrupt management.
>   *
> @@ -305,28 +305,14 @@ SYM(_CPU_Context_restore):
>   *    l0 = PSR
>   *    l1 = PC
>   *    l2 = nPC
> - *    l3 = trap type
> + *    l3 = interrupt vector number (this is not the trap type)
>   *
> - *  NOTE: By an executive defined convention, trap type is between 0 and 255 if
> - *        it is an asynchonous trap and 256 and 511 if it is synchronous.
> + *  NOTE: This trap handler is intended to service external interrupts.
>   */
>
>          .align 4
> -        PUBLIC(_ISR_Handler)
> -SYM(_ISR_Handler):
> -        /*
> -         *  Fix the return address for synchronous traps.
> -         */
> -
> -        andcc   %l3, SPARC_SYNCHRONOUS_TRAP_BIT_MASK, %g0
> -                                      ! Is this a synchronous trap?
> -        be,a    win_ovflow            ! No, then skip the adjustment
> -        nop                           ! DELAY
> -        mov     %l1, %l6              ! save trapped pc for debug info
> -        mov     %l2, %l1              ! do not return to the instruction
> -        add     %l2, 4, %l2           ! indicated
> -
> -win_ovflow:
> +        PUBLIC(_SPARC_Interrupt_trap)
> +SYM(_SPARC_Interrupt_trap):
>          /*
>           *  Save the globals this block uses.
>           *
> @@ -413,7 +399,7 @@ dont_do_the_window:
>           *  includes a regular minimum stack frame which will be used if
>           *  needed by register window overflow and underflow handlers.
>           *
> -         *  REGISTERS SAME AS AT _ISR_Handler
> +         *  REGISTERS SAME AS AT _SPARC_Interrupt_trap()
>           */
>
>          sub     %fp, CPU_INTERRUPT_FRAME_SIZE, %sp
> @@ -439,9 +425,6 @@ dont_do_the_window:
>
>          rd      %y, %g1
>          st      %g1, [%sp + ISF_Y_OFFSET]      ! save y
> -        st      %l6, [%sp + ISF_TPC_OFFSET]    ! save real trapped pc
> -
> -        mov     %sp, %o1                       ! 2nd arg to ISR Handler
>
>          /*
>           *  Increment ISR nest level and Thread dispatch disable level.
> @@ -520,26 +503,16 @@ dont_switch_stacks:
>          sub      %sp, SPARC_MINIMUM_STACK_FRAME_SIZE, %sp
>
>          /*
> -         *  Check if we have an external interrupt (trap 0x11 - 0x1f). If so,
> -         *  set the PIL in the %psr to mask off interrupts with lower priority.
> +         *  Set the PIL in the %psr to mask off interrupts with lower priority.
>           *  The original %psr in %l0 is not modified since it will be restored
>           *  when the interrupt handler returns.
>           */
>
>          mov      %l0, %g5
> -        and      %l3, 0x0ff, %g4
> -        subcc    %g4, 0x11, %g0
> -        bl       dont_fix_pil
> -        subcc    %g4, 0x1f, %g0
> -        bg       dont_fix_pil
> -        sll      %g4, 8, %g4
> +        sll      %l3, 8, %g4
>          and      %g4, SPARC_PSR_PIL_MASK, %g4
>          andn     %l0, SPARC_PSR_PIL_MASK, %g5
> -        ba       pil_fixed
>          or       %g4, %g5, %g5
> -dont_fix_pil:
> -        or       %g5, SPARC_PSR_PIL_MASK, %g5
> -pil_fixed:
>
>  #if SPARC_HAS_FPU == 1
>          /*
> @@ -552,23 +525,10 @@ pil_fixed:
>          wr       %g5, SPARC_PSR_ET_MASK, %psr ! **** ENABLE TRAPS ****
>
>          /*
> -         *  Vector to user's handler.
> -         *
> -         *  NOTE: TBR may no longer have vector number in it since
> -         *        we just enabled traps.  It is definitely in l3.
> +         *  Call _SPARC_Interrupt_dispatch( %l3 )
>           */
> -
> -        sethi    %hi(SYM(_ISR_Vector_table)), %g4
> -        or       %g4, %lo(SYM(_ISR_Vector_table)), %g4
> -        and      %l3, 0xFF, %g5         ! remove synchronous trap indicator
> -        sll      %g5, 2, %g5            ! g5 = offset into table
> -        ld       [%g4 + %g5], %g4       ! g4 = _ISR_Vector_table[ vector ]
> -
> -
> -                                        ! o1 = 2nd arg = address of the ISF
> -                                        !   WAS LOADED WHEN ISF WAS SAVED!!!
>          mov      %l3, %o0               ! o0 = 1st arg = vector number
> -        call     %g4
> +        call     SYM(_SPARC_Interrupt_dispatch)
>  #if defined(RTEMS_PROFILING)
>           mov     %o5, %l3               ! save interrupt entry instant
>  #else
> @@ -780,8 +740,8 @@ isr_dispatch:
>           *  The CWP in place at this point may be different from
>           *  that which was in effect at the beginning of the ISR if we
>           *  have been context switched between the beginning of this invocation
> -         *  of _ISR_Handler and this point.  Thus the CWP and WIM should
> -         *  not be changed back to their values at ISR entry time.  Any
> +         *  of _SPARC_Interrupt_trap() and this point.  Thus the CWP and WIM
> +         *  should not be changed back to their values at ISR entry time.  Any
>           *  changes to the PSR must preserve the CWP.
>           */
>
> diff --git a/cpukit/score/cpu/sparc/include/rtems/score/cpu.h b/cpukit/score/cpu/sparc/include/rtems/score/cpu.h
> index f3f50d4f78..0abc929c54 100644
> --- a/cpukit/score/cpu/sparc/include/rtems/score/cpu.h
> +++ b/cpukit/score/cpu/sparc/include/rtems/score/cpu.h
> @@ -743,9 +743,13 @@ extern const CPU_Trap_table_entry _CPU_Trap_slot_template;
>
>  #ifndef ASM
>
> -/*
> - *  ISR handler macros
> +/**
> + * @brief Dispatches the installed interrupt handlers.
> + *
> + * @param irq is the interrupt vector number of the external interrupt ranging
> + *   from 0 to 15.  This is not a trap number.
>   */
> +void _SPARC_Interrupt_dispatch( uint32_t irq );
>
>  /**
>   * Disable all interrupts for a critical section.  The previous
> diff --git a/cpukit/score/cpu/sparc/sparc-isr-handler.S b/cpukit/score/cpu/sparc/sparc-isr-handler.S
> new file mode 100644
> index 0000000000..068fad1e84
> --- /dev/null
> +++ b/cpukit/score/cpu/sparc/sparc-isr-handler.S
> @@ -0,0 +1,620 @@
> +/*
> + *  This file contains the basic algorithms for all assembly code used
> + *  in an specific CPU port of RTEMS.  These algorithms must be implemented
> + *  in assembly language.
> + *
> + *  COPYRIGHT (c) 1989-2011.
> + *  On-Line Applications Research Corporation (OAR).
> + *
> + *  Copyright (c) 2014, 2017 embedded brains GmbH
> + *
> + *  The license and distribution terms for this file may be
> + *  found in the file LICENSE in this distribution or at
> + *  http://www.rtems.org/license/LICENSE.
> + *
> + *  Ported to ERC32 implementation of the SPARC by On-Line Applications
> + *  Research Corporation (OAR) under contract to the European Space
> + *  Agency (ESA).
> + *
> + *  ERC32 modifications of respective RTEMS file: COPYRIGHT (c) 1995.
> + *  European Space Agency.
> + */
> +
> +#include <rtems/asm.h>
> +#include <rtems/score/percpu.h>
> +#include <libcpu/grlib-tn-0018.h>
> +
> +/*
> + *  void _ISR_Handler()
> + *
> + *  This routine provides the RTEMS interrupt management.
> + *
> + *  We enter this handler from the 4 instructions in the trap table with
> + *  the following registers assumed to be set as shown:
> + *
> + *    l0 = PSR
> + *    l1 = PC
> + *    l2 = nPC
> + *    l3 = trap type
> + *
> + *  NOTE: By an executive defined convention, trap type is between 0 and 255 if
> + *        it is an asynchonous trap and 256 and 511 if it is synchronous.
> + */
> +
> +        .align 4
> +        PUBLIC(_ISR_Handler)
> +SYM(_ISR_Handler):
> +        /*
> +         *  Fix the return address for synchronous traps.
> +         */
> +
> +        andcc   %l3, SPARC_SYNCHRONOUS_TRAP_BIT_MASK, %g0
> +                                      ! Is this a synchronous trap?
> +        be,a    win_ovflow            ! No, then skip the adjustment
> +        nop                           ! DELAY
> +        mov     %l1, %l6              ! save trapped pc for debug info
> +        mov     %l2, %l1              ! do not return to the instruction
> +        add     %l2, 4, %l2           ! indicated
> +
> +win_ovflow:
> +        /*
> +         *  Save the globals this block uses.
> +         *
> +         *  These registers are not restored from the locals.  Their contents
> +         *  are saved directly from the locals into the ISF below.
> +         */
> +
> +        mov     %g4, %l4                 ! save the globals this block uses
> +        mov     %g5, %l5
> +
> +        /*
> +         *  When at a "window overflow" trap, (wim == (1 << cwp)).
> +         *  If we get here like that, then process a window overflow.
> +         */
> +
> +        rd      %wim, %g4
> +        srl     %g4, %l0, %g5            ! g5 = win >> cwp ; shift count and CWP
> +                                         !   are LS 5 bits ; how convenient :)
> +        cmp     %g5, 1                   ! Is this an invalid window?
> +        bne     dont_do_the_window       ! No, then skip all this stuff
> +        ! we are using the delay slot
> +
> +        /*
> +         *  The following is same as a 1 position right rotate of WIM
> +         */
> +
> +        srl     %g4, 1, %g5              ! g5 = WIM >> 1
> +        sll     %g4, SPARC_NUMBER_OF_REGISTER_WINDOWS-1 , %g4
> +                                         ! g4 = WIM << (Number Windows - 1)
> +        or      %g4, %g5, %g4            ! g4 = (WIM >> 1) |
> +                                         !      (WIM << (Number Windows - 1))
> +
> +        /*
> +         *  At this point:
> +         *
> +         *    g4 = the new WIM
> +         *    g5 is free
> +         */
> +
> +        /*
> +         *  Since we are tinkering with the register windows, we need to
> +         *  make sure that all the required information is in global registers.
> +         */
> +
> +        save                          ! Save into the window
> +        wr      %g4, 0, %wim          ! WIM = new WIM
> +        nop                           ! delay slots
> +        nop
> +        nop
> +
> +        /*
> +         *  Now save the window just as if we overflowed to it.
> +         */
> +
> +        std     %l0, [%sp + CPU_STACK_FRAME_L0_OFFSET]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %l2, [%sp + CPU_STACK_FRAME_L2_OFFSET]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %l4, [%sp + CPU_STACK_FRAME_L4_OFFSET]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %l6, [%sp + CPU_STACK_FRAME_L6_OFFSET]
> +        SPARC_LEON3FT_B2BST_NOP
> +
> +        std     %i0, [%sp + CPU_STACK_FRAME_I0_OFFSET]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %i2, [%sp + CPU_STACK_FRAME_I2_OFFSET]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %i4, [%sp + CPU_STACK_FRAME_I4_OFFSET]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %i6, [%sp + CPU_STACK_FRAME_I6_FP_OFFSET]
> +
> +        restore
> +        nop
> +
> +dont_do_the_window:
> +        /*
> +         *  Global registers %g4 and %g5 are saved directly from %l4 and
> +         *  %l5 directly into the ISF below.
> +         */
> +
> +        /*
> +         *  Save the state of the interrupted task -- especially the global
> +         *  registers -- in the Interrupt Stack Frame.  Note that the ISF
> +         *  includes a regular minimum stack frame which will be used if
> +         *  needed by register window overflow and underflow handlers.
> +         *
> +         *  REGISTERS SAME AS AT _ISR_Handler
> +         */
> +
> +        sub     %fp, CPU_INTERRUPT_FRAME_SIZE, %sp
> +                                               ! make space for ISF
> +
> +        std     %l0, [%sp + ISF_PSR_OFFSET]    ! save psr, PC
> +        SPARC_LEON3FT_B2BST_NOP
> +        st      %l2, [%sp + ISF_NPC_OFFSET]    ! save nPC
> +        st      %g1, [%sp + ISF_G1_OFFSET]     ! save g1
> +        std     %g2, [%sp + ISF_G2_OFFSET]     ! save g2, g3
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %l4, [%sp + ISF_G4_OFFSET]     ! save g4, g5 -- see above
> +        SPARC_LEON3FT_B2BST_NOP
> +        st      %g7, [%sp + ISF_G7_OFFSET]     ! save g7
> +
> +        std     %i0, [%sp + ISF_I0_OFFSET]     ! save i0, i1
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %i2, [%sp + ISF_I2_OFFSET]     ! save i2, i3
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %i4, [%sp + ISF_I4_OFFSET]     ! save i4, i5
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %i6, [%sp + ISF_I6_FP_OFFSET]  ! save i6/fp, i7
> +
> +        rd      %y, %g1
> +        st      %g1, [%sp + ISF_Y_OFFSET]      ! save y
> +        st      %l6, [%sp + ISF_TPC_OFFSET]    ! save real trapped pc
> +
> +        mov     %sp, %o1                       ! 2nd arg to ISR Handler
> +
> +        /*
> +         *  Increment ISR nest level and Thread dispatch disable level.
> +         *
> +         *  Register usage for this section:
> +         *
> +         *    l6 = _Thread_Dispatch_disable_level value
> +         *    l7 = _ISR_Nest_level value
> +         *
> +         *  NOTE: It is assumed that l6 - l7 will be preserved until the ISR
> +         *        nest and thread dispatch disable levels are unnested.
> +         */
> +
> +        ld       [%g6 + PER_CPU_ISR_NEST_LEVEL], %l7
> +        ld       [%g6 + PER_CPU_THREAD_DISPATCH_DISABLE_LEVEL], %l6
> +
> +        add      %l7, 1, %l7
> +        st       %l7, [%g6 + PER_CPU_ISR_NEST_LEVEL]
> +        SPARC_LEON3FT_B2BST_NOP
> +
> +        add      %l6, 1, %l6
> +        st       %l6, [%g6 + PER_CPU_THREAD_DISPATCH_DISABLE_LEVEL]
> +
> +#if SPARC_HAS_FPU == 1
> +        /*
> +         * We cannot use an intermediate value for operations with the PSR[EF]
> +         * bit since they use a 13-bit sign extension and PSR[EF] is bit 12.
> +         */
> +        sethi    %hi(SPARC_PSR_EF_MASK), %l5
> +#endif
> +
> +        /*
> +         *  If ISR nest level was zero (now 1), then switch stack.
> +         */
> +
> +        mov      %sp, %fp
> +        subcc    %l7, 1, %l7             ! outermost interrupt handler?
> +        bnz      dont_switch_stacks      ! No, then do not switch stacks
> +
> +#if defined(RTEMS_PROFILING)
> +         sethi   %hi(_SPARC_Counter), %o5
> +        ld       [%o5 + %lo(_SPARC_Counter)], %l4
> +        call     %l4
> +         nop
> +        mov      %o0, %o5
> +#else
> +         nop
> +#endif
> +
> +        ld       [%g6 + PER_CPU_INTERRUPT_STACK_HIGH], %sp
> +
> +#if SPARC_HAS_FPU == 1
> +        /*
> +         * Test if the interrupted thread uses the floating point unit
> +         * (PSR[EF] == 1).  In case it uses the floating point unit, then store
> +         * the floating point status register.  This has the side-effect that
> +         * all pending floating point operations complete before the store
> +         * completes.  The PSR[EF] bit is restored after the call to the
> +         * interrupt handler.  Thus post-switch actions (e.g. signal handlers)
> +         * and context switch extensions may still corrupt the floating point
> +         * context.
> +         */
> +        andcc    %l0, %l5, %g0
> +        beq      dont_switch_stacks
> +         nop
> +        st      %fsr, [%g6 + SPARC_PER_CPU_FSR_OFFSET]
> +#endif
> +
> +dont_switch_stacks:
> +        /*
> +         *  Make sure we have a place on the stack for the window overflow
> +         *  trap handler to write into.  At this point it is safe to
> +         *  enable traps again.
> +         */
> +
> +        sub      %sp, SPARC_MINIMUM_STACK_FRAME_SIZE, %sp
> +
> +        /*
> +         *  Check if we have an external interrupt (trap 0x11 - 0x1f). If so,
> +         *  set the PIL in the %psr to mask off interrupts with lower priority.
> +         *  The original %psr in %l0 is not modified since it will be restored
> +         *  when the interrupt handler returns.
> +         */
> +
> +        mov      %l0, %g5
> +        and      %l3, 0x0ff, %g4
> +        subcc    %g4, 0x11, %g0
> +        bl       dont_fix_pil
> +        subcc    %g4, 0x1f, %g0
> +        bg       dont_fix_pil
> +        sll      %g4, 8, %g4
> +        and      %g4, SPARC_PSR_PIL_MASK, %g4
> +        andn     %l0, SPARC_PSR_PIL_MASK, %g5
> +        ba       pil_fixed
> +        or       %g4, %g5, %g5
> +dont_fix_pil:
> +        or       %g5, SPARC_PSR_PIL_MASK, %g5
> +pil_fixed:
> +
> +#if SPARC_HAS_FPU == 1
> +        /*
> +         * Clear the PSR[EF] bit of the interrupted context to ensure that
> +         * interrupt service routines cannot corrupt the floating point context.
> +         */
> +        andn     %g5, %l5, %g5
> +#endif
> +
> +        wr       %g5, SPARC_PSR_ET_MASK, %psr ! **** ENABLE TRAPS ****
> +
> +        /*
> +         *  Vector to user's handler.
> +         *
> +         *  NOTE: TBR may no longer have vector number in it since
> +         *        we just enabled traps.  It is definitely in l3.
> +         */
> +
> +        sethi    %hi(SYM(_ISR_Vector_table)), %g4
> +        or       %g4, %lo(SYM(_ISR_Vector_table)), %g4
> +        and      %l3, 0xFF, %g5         ! remove synchronous trap indicator
> +        sll      %g5, 2, %g5            ! g5 = offset into table
> +        ld       [%g4 + %g5], %g4       ! g4 = _ISR_Vector_table[ vector ]
> +
> +
> +                                        ! o1 = 2nd arg = address of the ISF
> +                                        !   WAS LOADED WHEN ISF WAS SAVED!!!
> +        mov      %l3, %o0               ! o0 = 1st arg = vector number
> +        call     %g4
> +#if defined(RTEMS_PROFILING)
> +         mov     %o5, %l3               ! save interrupt entry instant
> +#else
> +         nop                            ! delay slot
> +#endif
> +
> +#if defined(SPARC_USE_SYNCHRONOUS_FP_SWITCH)
> +        mov      %l0, %g1               ! PSR[EF] value of interrupted context
> +        ta       SPARC_SWTRAP_IRQDIS_FP ! **** DISABLE INTERRUPTS ****
> +#else
> +        ta       SPARC_SWTRAP_IRQDIS    ! **** DISABLE INTERRUPTS ****
> +#endif
> +
> +#if defined(RTEMS_PROFILING)
> +        cmp      %l7, 0
> +        bne      profiling_not_outer_most_exit
> +         nop
> +        call     %l4                    ! Call _SPARC_Counter.counter_read
> +         mov     %g1, %l4               ! Save previous interrupt status
> +        mov      %o0, %o2               ! o2 = 3rd arg = interrupt exit instant
> +        mov      %l3, %o1               ! o1 = 2nd arg = interrupt entry instant
> +        call     SYM(_Profiling_Outer_most_interrupt_entry_and_exit)
> +         mov     %g6, %o0               ! o0 = 1st arg = per-CPU control
> +profiling_not_outer_most_exit:
> +#endif
> +
> +        /*
> +         *  Decrement ISR nest level and Thread dispatch disable level.
> +         *
> +         *  Register usage for this section:
> +         *
> +         *    o2 = g6->dispatch_necessary value
> +         *    o3 = g6->isr_dispatch_disable value
> +         *    l6 = g6->thread_dispatch_disable_level value
> +         *    l7 = g6->isr_nest_level value
> +         */
> +
> +        ldub     [%g6 + PER_CPU_DISPATCH_NEEDED], %o2
> +        ld       [%g6 + PER_CPU_ISR_DISPATCH_DISABLE], %o3
> +        st       %l7, [%g6 + PER_CPU_ISR_NEST_LEVEL]
> +        SPARC_LEON3FT_B2BST_NOP
> +        sub      %l6, 1, %l6
> +        st       %l6, [%g6 + PER_CPU_THREAD_DISPATCH_DISABLE_LEVEL]
> +
> +        /*
> +         * Thread dispatching is necessary and allowed if and only if
> +         *   g6->dispatch_necessary == 1 and
> +         *   g6->isr_dispatch_disable == 0 and
> +         *   g6->thread_dispatch_disable_level == 0.
> +         *
> +         * Otherwise, continue with the simple return.
> +         */
> +        xor      %o2, 1, %o2
> +        or       %o2, %l6, %o2
> +        orcc     %o2, %o3, %o2
> +        bnz      simple_return
> +
> +        /*
> +         * Switch back on the interrupted tasks stack and add enough room to
> +         * invoke the dispatcher.  Doing this in the delay slot causes no harm,
> +         * since the stack pointer (%sp) is not used in the simple return path.
> +         */
> +         sub     %fp, SPARC_MINIMUM_STACK_FRAME_SIZE, %sp
> +
> +isr_dispatch:
> +
> +        /* Set ISR dispatch disable and thread dispatch disable level to one */
> +        mov      1, %l6
> +        st       %l6, [%g6 + PER_CPU_THREAD_DISPATCH_DISABLE_LEVEL]
> +        st       %l6, [%g6 + PER_CPU_ISR_DISPATCH_DISABLE]
> +
> +        /* Call _Thread_Do_dispatch(), this function will enable interrupts */
> +
> +        mov      0, %o1                 ! ISR level for _Thread_Do_dispatch()
> +
> +#if defined(SPARC_USE_LAZY_FP_SWITCH)
> +        /* Test if we interrupted a floating point thread (PSR[EF] == 1) */
> +        andcc   %l0, %l5, %g0
> +        be      .Lnon_fp_thread_dispatch
> +         ld     [%g6 + PER_CPU_OFFSET_EXECUTING], %l6
> +
> +        /* Set new floating point unit owner to executing thread */
> +        st      %l6, [%g6 + SPARC_PER_CPU_FP_OWNER_OFFSET]
> +
> +        call    SYM(_Thread_Do_dispatch)
> +         mov    %g6, %o0
> +
> +        /*
> +         * If we are still the floating point unit owner, then reset the
> +         * floating point unit owner to NULL, otherwise clear PSR[EF] in the
> +         * interrupt frame and let the FP disabled system call do the floating
> +         * point context save/restore.
> +         */
> +        ld      [%g6 + SPARC_PER_CPU_FP_OWNER_OFFSET], %l7
> +        cmp     %l6, %l7
> +        bne,a   .Ldisable_fp
> +         andn   %l0, %l5, %l0
> +        st      %g0, [%g6 + SPARC_PER_CPU_FP_OWNER_OFFSET]
> +        ba      .Lthread_dispatch_done
> +         nop
> +.Ldisable_fp:
> +        st       %l0, [%fp + ISF_PSR_OFFSET]
> +        ba      .Lthread_dispatch_done
> +         nop
> +.Lnon_fp_thread_dispatch:
> +#elif defined(SPARC_USE_SYNCHRONOUS_FP_SWITCH)
> +        /* Test if we interrupted a floating point thread (PSR[EF] == 1) */
> +        andcc   %l0, %l5, %g0
> +        be      .Lnon_fp_thread_dispatch
> +         nop
> +
> +        /*
> +         * Yes, this is a floating point thread, then save the floating point
> +         * context to a new stack frame.  Then do the thread dispatch.
> +         * Post-switch actions (e.g. signal handlers) and context switch
> +         * extensions may safely use the floating point unit.
> +         */
> +        sub     %sp, SPARC_FP_FRAME_SIZE, %sp
> +        std     %f0, [%sp + SPARC_FP_FRAME_OFFSET_FO_F1]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %f2, [%sp + SPARC_FP_FRAME_OFFSET_F2_F3]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %f4, [%sp + SPARC_FP_FRAME_OFFSET_F4_F5]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %f6, [%sp + SPARC_FP_FRAME_OFFSET_F6_F7]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %f8, [%sp + SPARC_FP_FRAME_OFFSET_F8_F9]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %f10, [%sp + SPARC_FP_FRAME_OFFSET_F1O_F11]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %f12, [%sp + SPARC_FP_FRAME_OFFSET_F12_F13]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %f14, [%sp + SPARC_FP_FRAME_OFFSET_F14_F15]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %f16, [%sp + SPARC_FP_FRAME_OFFSET_F16_F17]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %f18, [%sp + SPARC_FP_FRAME_OFFSET_F18_F19]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %f20, [%sp + SPARC_FP_FRAME_OFFSET_F2O_F21]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %f22, [%sp + SPARC_FP_FRAME_OFFSET_F22_F23]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %f24, [%sp + SPARC_FP_FRAME_OFFSET_F24_F25]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %f26, [%sp + SPARC_FP_FRAME_OFFSET_F26_F27]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %f28, [%sp + SPARC_FP_FRAME_OFFSET_F28_F29]
> +        SPARC_LEON3FT_B2BST_NOP
> +        std     %f30, [%sp + SPARC_FP_FRAME_OFFSET_F3O_F31]
> +        SPARC_LEON3FT_B2BST_NOP
> +        st      %fsr, [%sp + SPARC_FP_FRAME_OFFSET_FSR]
> +        call    SYM(_Thread_Do_dispatch)
> +         mov    %g6, %o0
> +
> +        /*
> +         * Restore the floating point context from stack frame and release the
> +         * stack frame.
> +         */
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_FO_F1], %f0
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_F2_F3], %f2
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_F4_F5], %f4
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_F6_F7], %f6
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_F8_F9], %f8
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_F1O_F11], %f10
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_F12_F13], %f12
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_F14_F15], %f14
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_F16_F17], %f16
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_F18_F19], %f18
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_F2O_F21], %f20
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_F22_F23], %f22
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_F24_F25], %f24
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_F26_F27], %f26
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_F28_F29], %f28
> +        ldd     [%sp + SPARC_FP_FRAME_OFFSET_F3O_F31], %f30
> +        ld      [%sp + SPARC_FP_FRAME_OFFSET_FSR], %fsr
> +        ba      .Lthread_dispatch_done
> +         add    %sp, SPARC_FP_FRAME_SIZE, %sp
> +
> +.Lnon_fp_thread_dispatch:
> +#endif
> +
> +        call    SYM(_Thread_Do_dispatch)
> +         mov    %g6, %o0
> +
> +#if SPARC_HAS_FPU == 1
> +.Lthread_dispatch_done:
> +#endif
> +
> +        ta       SPARC_SWTRAP_IRQDIS ! **** DISABLE INTERRUPTS ****
> +
> +        /*
> +         *  While we had ISR dispatching disabled in this thread,
> +         *  did we miss anything?  If so, then we need to do another
> +         *  _Thread_Do_dispatch() before leaving this ISR dispatch context.
> +         */
> +        ldub    [%g6 + PER_CPU_DISPATCH_NEEDED], %l7
> +
> +        orcc    %l7, %g0, %g0        ! Is a thread dispatch necessary?
> +        bne     isr_dispatch         ! Yes, then invoke the dispatcher again.
> +         mov    0, %o1               ! ISR level for _Thread_Do_dispatch()
> +
> +        /*
> +         * No, then set the ISR dispatch disable flag to zero and continue with
> +         * the simple return.
> +         */
> +        st       %g0, [%g6 + PER_CPU_ISR_DISPATCH_DISABLE]
> +
> +        /*
> +         *  The CWP in place at this point may be different from
> +         *  that which was in effect at the beginning of the ISR if we
> +         *  have been context switched between the beginning of this invocation
> +         *  of _ISR_Handler and this point.  Thus the CWP and WIM should
> +         *  not be changed back to their values at ISR entry time.  Any
> +         *  changes to the PSR must preserve the CWP.
> +         */
> +
> +simple_return:
> +        ld      [%fp + ISF_Y_OFFSET], %l5      ! restore y
> +        wr      %l5, 0, %y
> +
> +        ldd     [%fp + ISF_PSR_OFFSET], %l0    ! restore psr, PC
> +        ld      [%fp + ISF_NPC_OFFSET], %l2    ! restore nPC
> +        rd      %psr, %l3
> +        and     %l3, SPARC_PSR_CWP_MASK, %l3   ! want "current" CWP
> +        andn    %l0, SPARC_PSR_CWP_MASK, %l0   ! want rest from task
> +        or      %l3, %l0, %l0                  ! install it later...
> +        andn    %l0, SPARC_PSR_ET_MASK, %l0
> +
> +        /*
> +         *  Restore tasks global and out registers
> +         */
> +
> +        mov    %fp, %g1
> +
> +                                              ! g1 is restored later
> +        ldd     [%fp + ISF_G2_OFFSET], %g2    ! restore g2, g3
> +        ldd     [%fp + ISF_G4_OFFSET], %g4    ! restore g4, g5
> +        ld      [%fp + ISF_G7_OFFSET], %g7    ! restore g7
> +
> +        ldd     [%fp + ISF_I0_OFFSET], %i0    ! restore i0, i1
> +        ldd     [%fp + ISF_I2_OFFSET], %i2    ! restore i2, i3
> +        ldd     [%fp + ISF_I4_OFFSET], %i4    ! restore i4, i5
> +        ldd     [%fp + ISF_I6_FP_OFFSET], %i6 ! restore i6/fp, i7
> +
> +        /*
> +         *  Registers:
> +         *
> +         *   ALL global registers EXCEPT G1 and the input registers have
> +         *   already been restored and thuse off limits.
> +         *
> +         *   The following is the contents of the local registers:
> +         *
> +         *     l0 = original psr
> +         *     l1 = return address (i.e. PC)
> +         *     l2 = nPC
> +         *     l3 = CWP
> +         */
> +
> +        /*
> +         *  if (CWP + 1) is an invalid window then we need to reload it.
> +         *
> +         *  WARNING: Traps should now be disabled
> +         */
> +
> +        mov     %l0, %psr                  !  **** DISABLE TRAPS ****
> +        nop
> +        nop
> +        nop
> +        rd      %wim, %l4
> +        add     %l0, 1, %l6                ! l6 = cwp + 1
> +        and     %l6, SPARC_PSR_CWP_MASK, %l6 ! do the modulo on it
> +        srl     %l4, %l6, %l5              ! l5 = win >> cwp + 1 ; shift count
> +                                           !  and CWP are conveniently LS 5 bits
> +        cmp     %l5, 1                     ! Is tasks window invalid?
> +        bne     good_task_window
> +
> +        /*
> +         *  The following code is the same as a 1 position left rotate of WIM.
> +         */
> +
> +        sll     %l4, 1, %l5                ! l5 = WIM << 1
> +        srl     %l4, SPARC_NUMBER_OF_REGISTER_WINDOWS-1 , %l4
> +                                           ! l4 = WIM >> (Number Windows - 1)
> +        or      %l4, %l5, %l4              ! l4 = (WIM << 1) |
> +                                           !      (WIM >> (Number Windows - 1))
> +
> +        /*
> +         *  Now restore the window just as if we underflowed to it.
> +         */
> +
> +        wr      %l4, 0, %wim               ! WIM = new WIM
> +        nop                                ! must delay after writing WIM
> +        nop
> +        nop
> +        restore                            ! now into the tasks window
> +
> +        ldd     [%g1 + CPU_STACK_FRAME_L0_OFFSET], %l0
> +        ldd     [%g1 + CPU_STACK_FRAME_L2_OFFSET], %l2
> +        ldd     [%g1 + CPU_STACK_FRAME_L4_OFFSET], %l4
> +        ldd     [%g1 + CPU_STACK_FRAME_L6_OFFSET], %l6
> +        ldd     [%g1 + CPU_STACK_FRAME_I0_OFFSET], %i0
> +        ldd     [%g1 + CPU_STACK_FRAME_I2_OFFSET], %i2
> +        ldd     [%g1 + CPU_STACK_FRAME_I4_OFFSET], %i4
> +        ldd     [%g1 + CPU_STACK_FRAME_I6_FP_OFFSET], %i6
> +                                           ! reload of sp clobbers ISF
> +        save                               ! Back to ISR dispatch window
> +
> +good_task_window:
> +        TN0018_WAIT_IFLUSH %l3,%l4         ! GRLIB-TN-0018 work around macro
> +
> +        mov     %l0, %psr                  !  **** DISABLE TRAPS ****
> +        nop; nop; nop
> +                                           !  and restore condition codes.
> +        ld      [%g1 + ISF_G1_OFFSET], %g1 ! restore g1
> +        TN0018_FIX %l3,%l4                 ! GRLIB-TN-0018 work around macro
> +        jmp     %l1                        ! transfer control and
> +        rett    %l2                        ! go back to tasks window
> +
> +/* end of file */
> diff --git a/spec/build/cpukit/cpusparc.yml b/spec/build/cpukit/cpusparc.yml
> index 2186505577..5cd6cd7998 100644
> --- a/spec/build/cpukit/cpusparc.yml
> +++ b/spec/build/cpukit/cpusparc.yml
> @@ -39,6 +39,7 @@ source:
>  - cpukit/score/cpu/sparc/sparc-context-volatile-clobber.S
>  - cpukit/score/cpu/sparc/sparc-counter-asm.S
>  - cpukit/score/cpu/sparc/sparc-exception-frame-print.c
> +- cpukit/score/cpu/sparc/sparc-isr-handler.S
>  - cpukit/score/cpu/sparc/sparc-isr-install.c
>  - cpukit/score/cpu/sparc/syscall.S
>  - cpukit/score/cpu/sparc/window.S
> --
> 2.26.2
>
>
>
> _______________________________________________
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