[PATCH v7 08/12] lib: sbi: Extends sbi_ipi_raw_send() to use all available IPI devices

[Anup Patel]

On Mon, Oct 20, 2025 at 11:57 AM Nick Hu <nick.hu at sifive.com> wrote:
>
> A platform may contain multiple IPI devices. In certain use cases,
> such as power management, it may be necessary to send an IPI through a
> specific device to wake up a CPU. For example, if an IMSIC is powered
> down and reset, the core cannot receive IPIs from it, so the wake-up must
> instead be triggered through the CLINT.
>
> Suggested-by: Anup Patel <anup at brainfault.org>
> Signed-off-by: Nick Hu <nick.hu at sifive.com>

LGTM.

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

Regards,
Anup

> ---
>  include/sbi/sbi_ipi.h          |  2 +-
>  lib/sbi/sbi_hsm.c              |  2 +-
>  lib/sbi/sbi_ipi.c              | 16 +++++++++++++---
>  platform/generic/andes/ae350.c |  2 +-
>  4 files changed, 16 insertions(+), 6 deletions(-)
>
> diff --git a/include/sbi/sbi_ipi.h b/include/sbi/sbi_ipi.h
> index 26d1b66b7cfffbaa6f7cadd0fab8c810adfb1811..2c231041662bfb55b2f962ca48d724cf6aa53f6d 100644
> --- a/include/sbi/sbi_ipi.h
> +++ b/include/sbi/sbi_ipi.h
> @@ -88,7 +88,7 @@ int sbi_ipi_send_halt(ulong hmask, ulong hbase);
>
>  void sbi_ipi_process(void);
>
> -int sbi_ipi_raw_send(u32 hartindex);
> +int sbi_ipi_raw_send(u32 hartindex, bool all_devices);
>
>  void sbi_ipi_raw_clear(bool all_devices);
>
> diff --git a/lib/sbi/sbi_hsm.c b/lib/sbi/sbi_hsm.c
> index bb274b33d6ee5e3db9953f4b591502e4522d99d1..0d97b43e0cd8f7b4fc97407ef01007485e3f5a24 100644
> --- a/lib/sbi/sbi_hsm.c
> +++ b/lib/sbi/sbi_hsm.c
> @@ -364,7 +364,7 @@ int sbi_hsm_hart_start(struct sbi_scratch *scratch,
>            (hsm_device_has_hart_secondary_boot() && !init_count)) {
>                 rc = hsm_device_hart_start(hartid, scratch->warmboot_addr);
>         } else {
> -               rc = sbi_ipi_raw_send(hartindex);
> +               rc = sbi_ipi_raw_send(hartindex, true);
>         }
>
>         if (!rc)
> diff --git a/lib/sbi/sbi_ipi.c b/lib/sbi/sbi_ipi.c
> index ed9ccffb6c96cdfa1151a22d07c2bfc8181769bd..5b2d2f72eeb918a8877b4b8fbf201f2b9628f069 100644
> --- a/lib/sbi/sbi_ipi.c
> +++ b/lib/sbi/sbi_ipi.c
> @@ -88,7 +88,7 @@ static int sbi_ipi_send(struct sbi_scratch *scratch, u32 remote_hartindex,
>          */
>         if (!__atomic_fetch_or(&ipi_data->ipi_type,
>                                 BIT(event), __ATOMIC_RELAXED))
> -               ret = sbi_ipi_raw_send(remote_hartindex);
> +               ret = sbi_ipi_raw_send(remote_hartindex, false);
>
>         sbi_pmu_ctr_incr_fw(SBI_PMU_FW_IPI_SENT);
>
> @@ -271,8 +271,10 @@ void sbi_ipi_process(void)
>         }
>  }
>
> -int sbi_ipi_raw_send(u32 hartindex)
> +int sbi_ipi_raw_send(u32 hartindex, bool all_devices)
>  {
> +       struct sbi_ipi_device_node *entry;
> +
>         if (!ipi_dev || !ipi_dev->ipi_send)
>                 return SBI_EINVAL;
>
> @@ -287,7 +289,15 @@ int sbi_ipi_raw_send(u32 hartindex)
>          */
>         wmb();
>
> -       ipi_dev->ipi_send(hartindex);
> +       if (all_devices) {
> +               sbi_list_for_each_entry(entry, &ipi_dev_node_list, head) {
> +                       if (entry->dev->ipi_send)
> +                               entry->dev->ipi_send(hartindex);
> +               }
> +       } else {
> +               ipi_dev->ipi_send(hartindex);
> +       }
> +
>         return 0;
>  }
>
> diff --git a/platform/generic/andes/ae350.c b/platform/generic/andes/ae350.c
> index f06e207d80f58703098ef805a14e1f8764c2cb16..0808065745af21f5d65f0114ca33a23949280296 100644
> --- a/platform/generic/andes/ae350.c
> +++ b/platform/generic/andes/ae350.c
> @@ -35,7 +35,7 @@ static int ae350_hart_start(u32 hartid, ulong saddr)
>          * 2) the target hart is non-sleepable 25-series hart0
>          */
>         if (!sbi_init_count(hartindex) || (is_andes(25) && hartid == 0))
> -               return sbi_ipi_raw_send(hartindex);
> +               return sbi_ipi_raw_send(hartindex, false);
>
>         /* Write wakeup command to the sleep hart */
>         smu_set_command(&smu, WAKEUP_CMD, hartid);
>
> --
> 2.34.1
>