[PATCH v2 4/4] irqchip/apple-aic: Only access system registers on SoCs which provide them
From: Nick Chan <hidden>
Date: 2024-08-31 05:57:54
Also in:
asahi, linux-devicetree, lkml
Subsystem:
arm/apple machine support, irqchip drivers, the rest · Maintainers:
Sven Peter, Janne Grunau, Thomas Gleixner, Linus Torvalds
From: Konrad Dybcio <redacted> Starting from the A11 (T8015) SoC, Apple introuced system registers for fast IPI and UNCORE PMC control. These sysregs do not exist on earlier A7-A10 SoCs and trying to access them results in an instant crash. Restrict sysreg access within the AIC driver to configurations where use_fast_ipi is true to allow AIC to function properly on A7-A10 SoCs. As part of the restriction, the IPI-always-ack path in aic_handle_fiq() has been removed. If the code path were to be reached, the system is fast IPI capable and one of the fast IPI compatibles should be used instead. Signed-off-by: Konrad Dybcio <redacted> Co-developed-by: Nick Chan <redacted> Signed-off-by: Nick Chan <redacted> --- drivers/irqchip/irq-apple-aic.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-)
diff --git a/drivers/irqchip/irq-apple-aic.c b/drivers/irqchip/irq-apple-aic.c
index 01a3c79054f5..a6d812afb10d 100644
--- a/drivers/irqchip/irq-apple-aic.c
+++ b/drivers/irqchip/irq-apple-aic.c@@ -234,6 +234,7 @@ enum fiq_hwirq { AIC_NR_FIQ }; +/* 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 for local fast IPIs (M1+) */ static DEFINE_STATIC_KEY_TRUE(use_local_fast_ipi);
@@ -550,14 +551,9 @@ 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) && + (read_sysreg_s(SYS_IMP_APL_IPI_SR_EL1) & IPI_SR_PENDING)) + aic_handle_ipi(regs); if (TIMER_FIRING(read_sysreg(cntp_ctl_el0))) generic_handle_domain_irq(aic_irqc->hw_domain,
@@ -592,8 +588,9 @@ 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)) { + if (static_branch_likely(&use_fast_ipi) && + (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,
@@ -830,7 +827,8 @@ 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);
@@ -851,8 +849,9 @@ 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(&use_fast_ipi)) + sysreg_clear_set_s(SYS_IMP_APL_UPMCR0_EL1, UPMCR0_IMODE, + FIELD_PREP(UPMCR0_IMODE, UPMCR0_IMODE_OFF)); /* Commit all of the above */ isb();
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2.46.0