From: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxx>
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 <konrad.dybcio@xxxxxxxxxxxxxx>
Co-developed-by: Nick Chan <towinchenmi@xxxxxxxxx>
Signed-off-by: Nick Chan <towinchenmi@xxxxxxxxx>
---
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();
--
2.46.0
