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

[Gedare Bloom]

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?

> +void handle_trap_new ()
What is the purpose of this 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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