[PATCH 08/15] HiFive1: add irq dispatching function

[Denis Obrezkov]

2017-08-17 17:11 GMT+02:00 Gedare Bloom <gedare at rtems.org>:

> On Wed, Aug 16, 2017 at 11:12 AM, Denis Obrezkov
> <denisobrezkov at gmail.com> wrote:
> > ---
> >  c/src/lib/libbsp/riscv32/hifive1/irq/irq.c | 90
> ++++++++++++++++++++++++++++++
> >  1 file changed, 90 insertions(+)
> >  create mode 100644 c/src/lib/libbsp/riscv32/hifive1/irq/irq.c
> >
> > diff --git a/c/src/lib/libbsp/riscv32/hifive1/irq/irq.c
> b/c/src/lib/libbsp/riscv32/hifive1/irq/irq.c
> > new file mode 100644
> > index 0000000..6fd4e75
> > --- /dev/null
> > +++ b/c/src/lib/libbsp/riscv32/hifive1/irq/irq.c
> > @@ -0,0 +1,90 @@
> > +/**
> > + * @file
> > + *
> > + * @ingroup riscv_interrupt
> > + *
> > + * @brief Interrupt support.
> > + */
> > +
> > +/*
> > + * RISCV CPU Dependent Source
> > + *
> > + * Copyright (c) 2015 University of York.
> > + * Hesham ALMatary <hmka501 at york.ac.uk>
> > + *
> > + * Redistribution and use in source and binary forms, with or without
> > + * modification, are permitted provided that the following conditions
> > + * are met:
> > + * 1. Redistributions of source code must retain the above copyright
> > + *    notice, this list of conditions and the following disclaimer.
> > + * 2. Redistributions in binary form must reproduce the above copyright
> > + *    notice, this list of conditions and the following disclaimer in
> the
> > + *    documentation and/or other materials provided with the
> distribution.
> > + *
> > + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''
> AND
> > + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
> > + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
> PURPOSE
> > + * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE
> LIABLE
> > + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
> CONSEQUENTIAL
> > + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
> GOODS
> > + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
> > + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
> STRICT
> > + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
> ANY WAY
> > + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
> OF
> > + * SUCH DAMAGE.
> > + */
> > +
> > +#include <bsp/fe310.h>
> > +#include <bsp/irq.h>
> > +#include <bsp/irq-generic.h>
> > +
> > +/* Almost all of the jobs that the following functions should
> > + * do are implemented in cpukit
> > + */
> > +
> > +void bsp_interrupt_handler_default(rtems_vector_number vector)
> > +{
> > +    printk("spurious interrupt: %u\n", vector);
> > +}
> > +
> > +rtems_status_code bsp_interrupt_facility_initialize()
> > +{
> > +  return 0;
> > +}
> > +
> > +rtems_status_code bsp_interrupt_vector_enable(rtems_vector_number
> vector)
> > +{
> > +  return 0;
> > +}
> > +
> > +rtems_status_code bsp_interrupt_vector_disable(rtems_vector_number
> vector)
> > +{
> > +  return 0;
> > +}
> > +
> > +static uint32_t cause = 0;
> > +volatile uint64_t * mtimecmp = (volatile uint64_t *)0x02004000;
> > +volatile uint64_t * mtime = (volatile uint64_t *)0x0200bff8;
> > +
> What are these global variables used for?
>
mtime - memory mapped timer register with a current timer value,
mtimecmp - comparator, if mtime>=mtimecmp, then interrupt generated

>
> > +void handle_trap_new ()
> What is the purpose of this function?
>
I think it is better to rename it. It's an irq dispatching function.

>
> > +{
> > +    asm volatile ("csrr %0, mcause": "=r" (cause));
> It would be good to have a static inline function for reading this
> register.
>
> > +    if (cause & MCAUSE_INT) {
> > +      /* an interrupt occurred */
> > +      if ((cause & MCAUSE_MTIME) == MCAUSE_MTIME) {
> > +       /* Timer interrupt */
> > +           (*mtimecmp) = (*mtime) + FE310_CLOCK_PERIOD;
> > +        bsp_interrupt_handler_table[1].handler(bsp_interrupt_
> handler_table[1].arg);
> > +      } else if ((cause & MCAUSE_MEXT) == MCAUSE_MEXT) {
> > +             /*External interrupt */
> > +          asm volatile ("csrci mie, 0x800");
> > +      } else if ((cause & MCAUSE_MSWI) == MCAUSE_MSWI) {
> > +             /* Software interrupt */
> > +             volatile uint32_t * msip_reg = (volatile uint32_t *)
> 0x02000000;
> > +             *msip_reg = 0;
> > +      }
> > +    } else {
> > +      /* an exception occurred */
> > +    }
> > +
> > +}
> > --
> > 2.1.4
> >
> > _______________________________________________
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> > http://lists.rtems.org/mailman/listinfo/devel
>



-- 
Regards, Denis Obrezkov
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