>
> On 31. Aug 2024, at 07:57, Nick Chan <towinchenmi@xxxxxxxxx> wrote:
>
> Starting with the A11 (T8015) SoC, Apple began using arm64 sysregs for
> fast IPIs. However, on A11, there is no such things as "Local" fast IPIs,
> as the SYS_IMP_APL_IPI_RR_LOCAL_EL1 register does not seem to exist.
>
> Add a new feature level, used by the compatible "apple,t8015-aic",
> controlled by a static branch key named use_local_fast_ipi. When
> use_fast_ipi is true and use_local_fast_ipi is false, fast IPIs are used
> but all IPIs goes through the register SYS_IMP_APL_IPI_RR_GLOBAL_EL1, as
> "global" IPIs.
>
> Signed-off-by: Nick Chan <towinchenmi@xxxxxxxxx>
> ---
Reviewed-by: Sven Peter <sven@xxxxxxxxxxxxx>
> drivers/irqchip/irq-apple-aic.c | 24 +++++++++++++++++++++++-
> 1 file changed, 23 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/irqchip/irq-apple-aic.c b/drivers/irqchip/irq-apple-aic.c
> index 8d81d5fb3c50..01a3c79054f5 100644
> --- a/drivers/irqchip/irq-apple-aic.c
> +++ b/drivers/irqchip/irq-apple-aic.c
> @@ -235,6 +235,8 @@ enum fiq_hwirq {
> };
>
> static DEFINE_STATIC_KEY_TRUE(use_fast_ipi);
> +/* True if SYS_IMP_APL_IPI_RR_LOCAL_EL1 exists for local fast IPIs (M1+) */
> +static DEFINE_STATIC_KEY_TRUE(use_local_fast_ipi);
>
> struct aic_info {
> int version;
> @@ -252,6 +254,7 @@ struct aic_info {
>
> /* Features */
> bool fast_ipi;
> + bool local_fast_ipi;
> };
>
> static const struct aic_info aic1_info __initconst = {
> @@ -270,17 +273,32 @@ static const struct aic_info aic1_fipi_info __initconst = {
> .fast_ipi = true,
> };
>
> +static const struct aic_info aic1_local_fipi_info __initconst = {
> + .version = 1,
> +
> + .event = AIC_EVENT,
> + .target_cpu = AIC_TARGET_CPU,
> +
> + .fast_ipi = true,
> + .local_fast_ipi = true,
> +};
> +
> static const struct aic_info aic2_info __initconst = {
> .version = 2,
>
> .irq_cfg = AIC2_IRQ_CFG,
>
> .fast_ipi = true,
> + .local_fast_ipi = true,
> };
>
> static const struct of_device_id aic_info_match[] = {
> {
> .compatible = "apple,t8103-aic",
> + .data = &aic1_local_fipi_info,
> + },
> + {
> + .compatible = "apple,t8015-aic",
> .data = &aic1_fipi_info,
> },
> {
> @@ -750,7 +768,8 @@ static void aic_ipi_send_fast(int cpu)
> u64 cluster = MPIDR_CLUSTER(mpidr);
> u64 idx = MPIDR_CPU(mpidr);
>
> - if (MPIDR_CLUSTER(my_mpidr) == cluster)
> + if (static_branch_likely(&use_local_fast_ipi) &&
> + MPIDR_CLUSTER(my_mpidr) == cluster)
> write_sysreg_s(FIELD_PREP(IPI_RR_CPU, idx),
> SYS_IMP_APL_IPI_RR_LOCAL_EL1);
> else
> @@ -990,6 +1009,9 @@ static int __init aic_of_ic_init(struct device_node *node, struct device_node *p
> if (!irqc->info.fast_ipi)
> static_branch_disable(&use_fast_ipi);
>
> + if (!irqc->info.local_fast_ipi)
> + static_branch_disable(&use_local_fast_ipi);
> +
> irqc->info.die_stride = off - start_off;
>
> irqc->hw_domain = irq_domain_create_tree(of_node_to_fwnode(node),
> --
> 2.46.0
>
