On 29/8/2024 19:02, Nick Chan 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>
> ---
> drivers/irqchip/irq-apple-aic.c | 25 ++++++++++++++++++++++++-
> 1 file changed, 24 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/irqchip/irq-apple-aic.c b/drivers/irqchip/irq-apple-aic.c
> index 626aaeafa96c..1640074af2e1 100644
> --- a/drivers/irqchip/irq-apple-aic.c
> +++ b/drivers/irqchip/irq-apple-aic.c
> @@ -236,6 +236,8 @@ enum fiq_hwirq {
>
> /* True if UNCORE/UNCORE2 and Sn_... IPI registers are present and used (A11+) */
> static DEFINE_STATIC_KEY_TRUE(use_fast_ipi);
> +/* True if SYS_IMP_APL_IPI_RR_LOCAL_EL1 exists (M1+) */
> +static DEFINE_STATIC_KEY_TRUE(use_local_fast_ipi);
>
> struct aic_info {
> int version;
> @@ -253,6 +255,7 @@ struct aic_info {
>
> /* Features */
> bool fast_ipi;
> + bool local_fast_ipi;
> };
>
> static const struct aic_info aic1_info __initconst = {
> @@ -271,6 +274,16 @@ 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 = {
This patch is incorrectly disabling local fast IPI on aic2, it will be
corrected in v2.
> .version = 2,
>
> @@ -282,6 +295,10 @@ static const struct aic_info aic2_info __initconst = {
> 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,
> },
> {
> @@ -748,7 +765,8 @@ 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
> @@ -992,6 +1010,11 @@ static int __init aic_of_ic_init(struct device_node *node, struct device_node *p
> else
> static_branch_disable(&use_fast_ipi);
>
> + if (irqc->info.local_fast_ipi)
> + static_branch_enable(&use_local_fast_ipi);
> + else
> + 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),
Nick Chan
