[PATCH RESEND 2/3] irqchip/apple-aic: Only access IPI sysregs when use_fast_ipi is true
From: Nick Chan <hidden>
Date: 2024-08-29 11:05:31
Also in:
asahi, linux-arm-kernel, lkml
Subsystem:
arm/apple machine support, irqchip drivers, the rest · Maintainers:
Sven Peter, Janne Grunau, Thomas Gleixner, Linus Torvalds
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. While at it, remove the IPI-always-ack path on aic_handle_fiq. If we are able to reach there, we are on an IPI-capable system and should be using one of the IPI-capable compatibles, anyway. Signed-off-by: Konrad Dybcio <redacted> Signed-off-by: Nick Chan <redacted> --- drivers/irqchip/irq-apple-aic.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/drivers/irqchip/irq-apple-aic.c b/drivers/irqchip/irq-apple-aic.c
index 5c534d9fd2b0..626aaeafa96c 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); struct aic_info {
@@ -532,13 +533,9 @@ 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)))
@@ -574,8 +571,9 @@ 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,
@@ -811,7 +809,8 @@ 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);
@@ -832,8 +831,9 @@ 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();
--
2.46.0