[PATCH v3 3/4] lib: utils: Improve fdt_ipi
Anup Patel
anup at brainfault.org
Fri May 26 00:20:14 PDT 2023
On Mon, May 22, 2023 at 10:50 AM Xiang W <wxjstz at 126.com> wrote:
>
> Remove dummy driver. Optimize fdt_ipi_cold_init to exit the loop
> early.
>
> Signed-off-by: Xiang W <wxjstz at 126.com>
> ---
> lib/utils/ipi/fdt_ipi.c | 36 +++++++++++++++---------------------
> 1 file changed, 15 insertions(+), 21 deletions(-)
>
> diff --git a/lib/utils/ipi/fdt_ipi.c b/lib/utils/ipi/fdt_ipi.c
> index 66dc510..54f7c4c 100644
> --- a/lib/utils/ipi/fdt_ipi.c
> +++ b/lib/utils/ipi/fdt_ipi.c
> @@ -16,24 +16,17 @@
> extern struct fdt_ipi *fdt_ipi_drivers[];
> extern unsigned long fdt_ipi_drivers_size;
>
> -static struct fdt_ipi dummy = {
> - .match_table = NULL,
> - .cold_init = NULL,
> - .warm_init = NULL,
> - .exit = NULL,
> -};
> -
> -static struct fdt_ipi *current_driver = &dummy;
> +static struct fdt_ipi *current_driver = NULL;
>
> void fdt_ipi_exit(void)
> {
> - if (current_driver->exit)
> + if (current_driver && current_driver->exit)
> current_driver->exit();
> }
>
> static int fdt_ipi_warm_init(void)
> {
> - if (current_driver->warm_init)
> + if (current_driver && current_driver->warm_init)
> return current_driver->warm_init();
> return 0;
> }
> @@ -51,20 +44,21 @@ static int fdt_ipi_cold_init(void)
> noff = -1;
> while ((noff = fdt_find_match(fdt, noff,
> drv->match_table, &match)) >= 0) {
> - if (drv->cold_init) {
> - rc = drv->cold_init(fdt, noff, match);
> - if (rc == SBI_ENODEV)
> - continue;
> - if (rc)
> - return rc;
> - }
> - current_driver = drv;
> - }
> + /* drv->cold_init must not be NULL */
> + if (drv->cold_init == NULL)
> + return SBI_EFAIL;
>
> - if (current_driver != &dummy)
> - break;
> + rc = drv->cold_init(fdt, noff, match);
> + if (rc == SBI_ENODEV)
> + continue;
> + if (rc == 0)
> + current_driver = drv;
> + return rc;
We can't return here after finding one IPI device because we will
have multiple IPI devices on multi-die and multi-socket systems.
I have fixed it at the time of merging this patch.
Applied this patch to the riscv/opensbi repo.
Thanks,
Anup
> + }
> }
>
> + /* On some single-hart system there is no need for ipi,
> + * so we cannot return a failure here */
> return 0;
> }
>
> --
> 2.39.2
>
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