[RFC PATCH v2 4/9] lib: irqchip/plic: Factor out a context init function

Anup Patel anup at brainfault.org
Wed Jun 1 05:52:16 PDT 2022


On Mon, May 30, 2022 at 9:07 AM Samuel Holland <samuel at sholland.org> wrote:
>
> This simplifies both the callers and the callees by removing duplicated
> code and consolidating the error handling. It also fixes two bugs in the
> process:
>   1) ie_words was one too large when plic->num_src was a multiple of 32.
>   2) plic_set_ie takes a 32-bit mask, not a Boolean value, so the FPGA
>      platforms previously only enabled one out of every 32 interrupts.
>
> Signed-off-by: Samuel Holland <samuel at sholland.org>

Looks good to me.

Reviewed-by: Anup Patel <anup at brainfault.org>

Regards,
Anup

> ---
>
> Changes in v2:
>  - New patch for v2
>
>  include/sbi_utils/irqchip/plic.h   |  8 ++---
>  lib/utils/irqchip/plic.c           | 55 ++++++++++++++++--------------
>  platform/fpga/ariane/platform.c    | 19 +++++------
>  platform/fpga/openpiton/platform.c | 19 +++++------
>  4 files changed, 48 insertions(+), 53 deletions(-)
>
> diff --git a/include/sbi_utils/irqchip/plic.h b/include/sbi_utils/irqchip/plic.h
> index 50be5df..8f21af6 100644
> --- a/include/sbi_utils/irqchip/plic.h
> +++ b/include/sbi_utils/irqchip/plic.h
> @@ -17,14 +17,12 @@ struct plic_data {
>         unsigned long num_src;
>  };
>
> +int plic_context_init(const struct plic_data *plic, int context_id,
> +                     bool enable, u32 threshold);
> +
>  int plic_warm_irqchip_init(const struct plic_data *plic,
>                            int m_cntx_id, int s_cntx_id);
>
>  int plic_cold_irqchip_init(const struct plic_data *plic);
>
> -void plic_set_thresh(const struct plic_data *plic, u32 cntxid, u32 val);
> -
> -void plic_set_ie(const struct plic_data *plic, u32 cntxid,
> -                u32 word_index, u32 val);
> -
>  #endif
> diff --git a/lib/utils/irqchip/plic.c b/lib/utils/irqchip/plic.c
> index 4c334ec..9bd3bf1 100644
> --- a/lib/utils/irqchip/plic.c
> +++ b/lib/utils/irqchip/plic.c
> @@ -5,6 +5,7 @@
>   *
>   * Authors:
>   *   Anup Patel <anup.patel at wdc.com>
> + *   Samuel Holland <samuel at sholland.org>
>   */
>
>  #include <sbi/riscv_io.h>
> @@ -28,61 +29,63 @@ static void plic_set_priority(const struct plic_data *plic, u32 source, u32 val)
>         writel(val, plic_priority);
>  }
>
> -void plic_set_thresh(const struct plic_data *plic, u32 cntxid, u32 val)
> +static void plic_set_thresh(const struct plic_data *plic, u32 cntxid, u32 val)
>  {
>         volatile void *plic_thresh;
>
> -       if (!plic)
> -               return;
> -
>         plic_thresh = (char *)plic->addr +
>                       PLIC_CONTEXT_BASE + PLIC_CONTEXT_STRIDE * cntxid;
>         writel(val, plic_thresh);
>  }
>
> -void plic_set_ie(const struct plic_data *plic, u32 cntxid,
> -                u32 word_index, u32 val)
> +static void plic_set_ie(const struct plic_data *plic, u32 cntxid,
> +                       u32 word_index, u32 val)
>  {
>         volatile char *plic_ie;
>
> -       if (!plic)
> -               return;
> -
>         plic_ie = (char *)plic->addr +
>                    PLIC_ENABLE_BASE + PLIC_ENABLE_STRIDE * cntxid;
>         writel(val, plic_ie + word_index * 4);
>  }
>
> -int plic_warm_irqchip_init(const struct plic_data *plic,
> -                          int m_cntx_id, int s_cntx_id)
> +int plic_context_init(const struct plic_data *plic, int context_id,
> +                     bool enable, u32 threshold)
>  {
> -       size_t i, ie_words;
> +       u32 ie_words, ie_value;
>
> -       if (!plic)
> +       if (!plic || context_id < 0)
>                 return SBI_EINVAL;
>
> -       ie_words = plic->num_src / 32 + 1;
> +       ie_words = (plic->num_src + 31) / 32;
> +       ie_value = enable ? 0xffffffffU : 0U;
> +
> +       for (u32 i = 0; i < ie_words; i++)
> +               plic_set_ie(plic, context_id, i, ie_value);
> +
> +       plic_set_thresh(plic, context_id, threshold);
> +
> +       return 0;
> +}
> +
> +int plic_warm_irqchip_init(const struct plic_data *plic,
> +                          int m_cntx_id, int s_cntx_id)
> +{
> +       int ret;
>
>         /* By default, disable all IRQs for M-mode of target HART */
>         if (m_cntx_id > -1) {
> -               for (i = 0; i < ie_words; i++)
> -                       plic_set_ie(plic, m_cntx_id, i, 0);
> +               ret = plic_context_init(plic, m_cntx_id, false, 0x7);
> +               if (ret)
> +                       return ret;
>         }
>
>         /* By default, disable all IRQs for S-mode of target HART */
>         if (s_cntx_id > -1) {
> -               for (i = 0; i < ie_words; i++)
> -                       plic_set_ie(plic, s_cntx_id, i, 0);
> +               ret = plic_context_init(plic, m_cntx_id, false, 0x7);
> +               if (ret)
> +                       return ret;
>         }
>
> -       /* By default, disable M-mode threshold */
> -       if (m_cntx_id > -1)
> -               plic_set_thresh(plic, m_cntx_id, 0x7);
> -
> -       /* By default, disable S-mode threshold */
> -       if (s_cntx_id > -1)
> -               plic_set_thresh(plic, s_cntx_id, 0x7);
> -
>         return 0;
>  }
>
> diff --git a/platform/fpga/ariane/platform.c b/platform/fpga/ariane/platform.c
> index 3fdc03b..56a666b 100644
> --- a/platform/fpga/ariane/platform.c
> +++ b/platform/fpga/ariane/platform.c
> @@ -99,24 +99,21 @@ static int ariane_console_init(void)
>
>  static int plic_ariane_warm_irqchip_init(int m_cntx_id, int s_cntx_id)
>  {
> -       size_t i, ie_words = ARIANE_PLIC_NUM_SOURCES / 32 + 1;
> +       int ret;
>
>         /* By default, enable all IRQs for M-mode of target HART */
>         if (m_cntx_id > -1) {
> -               for (i = 0; i < ie_words; i++)
> -                       plic_set_ie(&plic, m_cntx_id, i, 1);
> +               ret = plic_context_init(&plic, m_cntx_id, true, 0x1);
> +               if (ret)
> +                       return ret;
>         }
> +
>         /* Enable all IRQs for S-mode of target HART */
>         if (s_cntx_id > -1) {
> -               for (i = 0; i < ie_words; i++)
> -                       plic_set_ie(&plic, s_cntx_id, i, 1);
> +               ret = plic_context_init(&plic, s_cntx_id, true, 0x0);
> +               if (ret)
> +                       return ret;
>         }
> -       /* By default, enable M-mode threshold */
> -       if (m_cntx_id > -1)
> -               plic_set_thresh(&plic, m_cntx_id, 1);
> -       /* By default, disable S-mode threshold */
> -       if (s_cntx_id > -1)
> -               plic_set_thresh(&plic, s_cntx_id, 0);
>
>         return 0;
>  }
> diff --git a/platform/fpga/openpiton/platform.c b/platform/fpga/openpiton/platform.c
> index 15e289a..7ca2123 100644
> --- a/platform/fpga/openpiton/platform.c
> +++ b/platform/fpga/openpiton/platform.c
> @@ -134,24 +134,21 @@ static int openpiton_console_init(void)
>
>  static int plic_openpiton_warm_irqchip_init(int m_cntx_id, int s_cntx_id)
>  {
> -       size_t i, ie_words = plic.num_src / 32 + 1;
> +       int ret;
>
>         /* By default, enable all IRQs for M-mode of target HART */
>         if (m_cntx_id > -1) {
> -               for (i = 0; i < ie_words; i++)
> -                       plic_set_ie(&plic, m_cntx_id, i, 1);
> +               ret = plic_context_init(&plic, m_cntx_id, true, 0x1);
> +               if (ret)
> +                       return ret;
>         }
> +
>         /* Enable all IRQs for S-mode of target HART */
>         if (s_cntx_id > -1) {
> -               for (i = 0; i < ie_words; i++)
> -                       plic_set_ie(&plic, s_cntx_id, i, 1);
> +               ret = plic_context_init(&plic, s_cntx_id, true, 0x0);
> +               if (ret)
> +                       return ret;
>         }
> -       /* By default, enable M-mode threshold */
> -       if (m_cntx_id > -1)
> -               plic_set_thresh(&plic, m_cntx_id, 1);
> -       /* By default, disable S-mode threshold */
> -       if (s_cntx_id > -1)
> -               plic_set_thresh(&plic, s_cntx_id, 0);
>
>         return 0;
>  }
> --
> 2.35.1
>
>
> --
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