On Thu, Sep 29, 2022, at 16:40, Konrad Dybcio wrote:
> Add support for A7-A11 SoCs by if-ing out some features only present
> on:
>
> * A11 & newer (implementation-defined IPI & UNCORE registers)
> * A11[1] & newer (fast IPI support).
>
> Also, annotate IPI regs support in the aic struct so that the driver
> can tell whether the SoC supports these, as they are written to,
> even if fast IPI is disabled. This in turn causes a crash on older
> platforms, as the implemention-defined registers either do
> something else or are not supposed to be touched - definitely not a
> NOP though.
>
> [1] A11 is supposed to use this feature, but it currently doesn't work
> for reasons unknown and hence remains disabled. It can easily be enabled
> on A11 only, as there is a SoC-specific compatible in the DT with a
> fallback to apple,aic, so that the interrupt controller gets to probe
> regardless of whether IPI Sn_... registers are used or not.
> That said, it is not yet necessary, especially with only one core up,
> and it has worked a-ok so far.
>
> Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxx>
> ---
> Changes since v1:
> - remove EL2 register check (dts change covered this)
> - use static_branch instead of ifs
> - rename "uncore2 registers" to "uncore registers" in added code and
> update the commit message accordingly
> - create a "legacy" config struct for pre-A11 targets
> - rewrite the commit message a bit to match actual status
>
> drivers/irqchip/irq-apple-aic.c | 56 ++++++++++++++++++++++++---------
> 1 file changed, 41 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/irqchip/irq-apple-aic.c b/drivers/irqchip/irq-apple-aic.c
> index 1c2813ad8bbe..cdef99bfcfb3 100644
> --- a/drivers/irqchip/irq-apple-aic.c
> +++ b/drivers/irqchip/irq-apple-aic.c
> @@ -229,6 +229,7 @@
> #define AIC_TMR_EL02_VIRT AIC_TMR_GUEST_VIRT
>
> static DEFINE_STATIC_KEY_TRUE(use_fast_ipi);
> +static DEFINE_STATIC_KEY_TRUE(has_uncore_regs);
>
> struct aic_info {
> int version;
> @@ -246,6 +247,7 @@ struct aic_info {
>
> /* Features */
> bool fast_ipi;
> + bool uncore_regs;
> };
>
> static const struct aic_info aic1_info = {
> @@ -253,6 +255,8 @@ static const struct aic_info aic1_info = {
>
> .event = AIC_EVENT,
> .target_cpu = AIC_TARGET_CPU,
> +
> + .uncore_regs = true,
> };
>
> static const struct aic_info aic1_fipi_info = {
> @@ -264,6 +268,13 @@ static const struct aic_info aic1_fipi_info = {
> .fast_ipi = true,
> };
>
> +static const struct aic_info aic1_legacy_info = {
> + .version = 1,
> +
> + .event = AIC_EVENT,
> + .target_cpu = AIC_TARGET_CPU,
> +};
> +
> static const struct aic_info aic2_info = {
> .version = 2,
>
> @@ -273,6 +284,10 @@ static const struct aic_info aic2_info = {
> };
>
> static const struct of_device_id aic_info_match[] = {
> + {
> + .compatible = "apple,s5l8960x-aic",
> + .data = &aic1_legacy_info,
> + },
Maybe I'm confused but shouldn't this be the apple,aic fallback and uncore_regs
should be enabled for e.g. t8103-aic then?
> {
> .compatible = "apple,t8103-aic",
> .data = &aic1_fipi_info,
> @@ -524,12 +539,14 @@ static void __exception_irq_entry
> aic_handle_fiq(struct pt_regs *regs)
> * we check for everything here, even things we don't support yet.
> */
>
> - if (read_sysreg_s(SYS_IMP_APL_IPI_SR_EL1) & IPI_SR_PENDING) {
> - if (static_branch_likely(&use_fast_ipi)) {
> - aic_handle_ipi(regs);
> - } else {
> - pr_err_ratelimited("Fast IPI fired. Acking.\n");
> - write_sysreg_s(IPI_SR_PENDING, SYS_IMP_APL_IPI_SR_EL1);
> + if (static_branch_likely(&use_fast_ipi)) {
> + if (read_sysreg_s(SYS_IMP_APL_IPI_SR_EL1) & IPI_SR_PENDING) {
> + if (static_branch_likely(&use_fast_ipi)) {
> + aic_handle_ipi(regs);
> + } else {
> + pr_err_ratelimited("Fast IPI fired. Acking.\n");
> + write_sysreg_s(IPI_SR_PENDING, SYS_IMP_APL_IPI_SR_EL1);
> + }
This doesn't make much sense:
if (A) {
if (B) {
if (A) { // A is already guaranteed to be true here, why check it again?
// ...
} else {
// how can this ever be reached then?
}
}
}
> }
> }
>
> @@ -566,12 +583,14 @@ static void __exception_irq_entry
> aic_handle_fiq(struct pt_regs *regs)
> AIC_FIQ_HWIRQ(irq));
> }
>
> - if (FIELD_GET(UPMCR0_IMODE, read_sysreg_s(SYS_IMP_APL_UPMCR0_EL1)) ==
> UPMCR0_IMODE_FIQ &&
> - (read_sysreg_s(SYS_IMP_APL_UPMSR_EL1) & UPMSR_IACT)) {
> - /* Same story with uncore PMCs */
> - pr_err_ratelimited("Uncore PMC FIQ fired. Masking.\n");
> - sysreg_clear_set_s(SYS_IMP_APL_UPMCR0_EL1, UPMCR0_IMODE,
> - FIELD_PREP(UPMCR0_IMODE, UPMCR0_IMODE_OFF));
> + if (static_branch_likely(&has_uncore_regs)) {
> + if (FIELD_GET(UPMCR0_IMODE, read_sysreg_s(SYS_IMP_APL_UPMCR0_EL1)) ==
> + UPMCR0_IMODE_FIQ && (read_sysreg_s(SYS_IMP_APL_UPMSR_EL1) &
> UPMSR_IACT)) {
> + /* Same story with uncore PMCs */
> + pr_err_ratelimited("Uncore PMC FIQ fired. Masking.\n");
> + sysreg_clear_set_s(SYS_IMP_APL_UPMCR0_EL1, UPMCR0_IMODE,
> + FIELD_PREP(UPMCR0_IMODE, UPMCR0_IMODE_OFF));
> + }
> }
> }
>
> @@ -944,7 +963,8 @@ static int aic_init_cpu(unsigned int cpu)
> /* Mask all hard-wired per-CPU IRQ/FIQ sources */
>
> /* Pending Fast IPI FIQs */
> - write_sysreg_s(IPI_SR_PENDING, SYS_IMP_APL_IPI_SR_EL1);
> + if (static_branch_likely(&use_fast_ipi))
> + write_sysreg_s(IPI_SR_PENDING, SYS_IMP_APL_IPI_SR_EL1);
>
> /* Timer FIQs */
> sysreg_clear_set(cntp_ctl_el0, 0, ARCH_TIMER_CTRL_IT_MASK);
> @@ -965,8 +985,9 @@ static int aic_init_cpu(unsigned int cpu)
> FIELD_PREP(PMCR0_IMODE, PMCR0_IMODE_OFF));
>
> /* Uncore PMC FIQ */
> - sysreg_clear_set_s(SYS_IMP_APL_UPMCR0_EL1, UPMCR0_IMODE,
> - FIELD_PREP(UPMCR0_IMODE, UPMCR0_IMODE_OFF));
> + if (static_branch_likely(&has_uncore_regs))
> + sysreg_clear_set_s(SYS_IMP_APL_UPMCR0_EL1, UPMCR0_IMODE,
> + FIELD_PREP(UPMCR0_IMODE, UPMCR0_IMODE_OFF));
>
> /* Commit all of the above */
> isb();
> @@ -1125,6 +1146,11 @@ 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.uncore_regs)
> + static_branch_enable(&has_uncore_regs);
> + else
> + static_branch_disable(&has_uncore_regs);
> +
> irqc->info.die_stride = off - start_off;
>
> irqc->hw_domain = irq_domain_create_tree(of_node_to_fwnode(node),
> --
> 2.30.2
Sven
