From 8848f0665b3cd4fbb3107b384f5205380c90634d Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 15 Jun 2021 12:12:24 +0100 Subject: arm64: Add cpuidle context save/restore helpers As we need to start doing some additional work on all idle paths, let's introduce a set of macros that will perform the work related to the GICv3 pseudo-NMI idle entry exit. Stubs are introduced to 32bit ARM for compatibility. As these helpers are currently unused, there is no functional change. Tested-by: Valentin Schneider Reviewed-by: Lorenzo Pieralisi Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210615111227.2454465-2-maz@kernel.org Signed-off-by: Will Deacon --- arch/arm/include/asm/cpuidle.h | 5 +++++ arch/arm64/include/asm/cpuidle.h | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 40 insertions(+) (limited to 'arch') diff --git a/arch/arm/include/asm/cpuidle.h b/arch/arm/include/asm/cpuidle.h index 0d67ed682e07..dc8f53f1a219 100644 --- a/arch/arm/include/asm/cpuidle.h +++ b/arch/arm/include/asm/cpuidle.h @@ -49,4 +49,9 @@ extern int arm_cpuidle_suspend(int index); extern int arm_cpuidle_init(int cpu); +struct arm_cpuidle_irq_context { }; + +#define arm_cpuidle_save_irq_context(c) (void)c +#define arm_cpuidle_restore_irq_context(c) (void)c + #endif diff --git a/arch/arm64/include/asm/cpuidle.h b/arch/arm64/include/asm/cpuidle.h index 3c5ddb429ea2..14a19d1141bd 100644 --- a/arch/arm64/include/asm/cpuidle.h +++ b/arch/arm64/include/asm/cpuidle.h @@ -18,4 +18,39 @@ static inline int arm_cpuidle_suspend(int index) return -EOPNOTSUPP; } #endif + +#ifdef CONFIG_ARM64_PSEUDO_NMI +#include + +struct arm_cpuidle_irq_context { + unsigned long pmr; + unsigned long daif_bits; +}; + +#define arm_cpuidle_save_irq_context(__c) \ + do { \ + struct arm_cpuidle_irq_context *c = __c; \ + if (system_uses_irq_prio_masking()) { \ + c->daif_bits = read_sysreg(daif); \ + write_sysreg(c->daif_bits | PSR_I_BIT | PSR_F_BIT, \ + daif); \ + c->pmr = gic_read_pmr(); \ + gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET); \ + } \ + } while (0) + +#define arm_cpuidle_restore_irq_context(__c) \ + do { \ + struct arm_cpuidle_irq_context *c = __c; \ + if (system_uses_irq_prio_masking()) { \ + gic_write_pmr(c->pmr); \ + write_sysreg(c->daif_bits, daif); \ + } \ + } while (0) +#else +struct arm_cpuidle_irq_context { }; + +#define arm_cpuidle_save_irq_context(c) (void)c +#define arm_cpuidle_restore_irq_context(c) (void)c +#endif #endif -- cgit v1.2.3 From d4dc10277255afc303de4f00cbee0b9ce74d870f Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 15 Jun 2021 12:12:25 +0100 Subject: arm64: Convert cpu_do_idle() to using cpuidle context helpers Now that we have helpers that are aware of the pseudo-NMI feature, introduce them to cpu_do_idle(). This allows for some nice cleanup. No functional change intended. Tested-by: Valentin Schneider Reviewed-by: Lorenzo Pieralisi Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20210615111227.2454465-3-maz@kernel.org Signed-off-by: Will Deacon --- arch/arm64/kernel/process.c | 41 +++++++++-------------------------------- 1 file changed, 9 insertions(+), 32 deletions(-) (limited to 'arch') diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index b4bb67f17a2c..b715c6b2558f 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -46,9 +46,9 @@ #include #include -#include #include #include +#include #include #include #include @@ -74,33 +74,6 @@ EXPORT_SYMBOL_GPL(pm_power_off); void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd); -static void noinstr __cpu_do_idle(void) -{ - dsb(sy); - wfi(); -} - -static void noinstr __cpu_do_idle_irqprio(void) -{ - unsigned long pmr; - unsigned long daif_bits; - - daif_bits = read_sysreg(daif); - write_sysreg(daif_bits | PSR_I_BIT | PSR_F_BIT, daif); - - /* - * Unmask PMR before going idle to make sure interrupts can - * be raised. - */ - pmr = gic_read_pmr(); - gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET); - - __cpu_do_idle(); - - gic_write_pmr(pmr); - write_sysreg(daif_bits, daif); -} - /* * cpu_do_idle() * @@ -112,10 +85,14 @@ static void noinstr __cpu_do_idle_irqprio(void) */ void noinstr cpu_do_idle(void) { - if (system_uses_irq_prio_masking()) - __cpu_do_idle_irqprio(); - else - __cpu_do_idle(); + struct arm_cpuidle_irq_context context; + + arm_cpuidle_save_irq_context(&context); + + dsb(sy); + wfi(); + + arm_cpuidle_restore_irq_context(&context); } /* -- cgit v1.2.3 From 77345ef70445a8f16e0685dade0d68bdf41f19d7 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 15 Jun 2021 12:12:27 +0100 Subject: arm64: suspend: Use cpuidle context helpers in cpu_suspend() Use cpuidle context helpers to switch to using DAIF.IF instead of PMR to mask interrupts, ensuring that we suspend with interrupts being able to reach the CPU interface. Signed-off-by: Marc Zyngier Reviewed-by: Sudeep Holla Link: https://lore.kernel.org/r/20210615111227.2454465-5-maz@kernel.org Signed-off-by: Will Deacon --- arch/arm64/kernel/suspend.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/arm64/kernel/suspend.c b/arch/arm64/kernel/suspend.c index e3f72df9509d..938ce6fbee8a 100644 --- a/arch/arm64/kernel/suspend.c +++ b/arch/arm64/kernel/suspend.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include #include @@ -91,6 +92,7 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) int ret = 0; unsigned long flags; struct sleep_stack_data state; + struct arm_cpuidle_irq_context context; /* Report any MTE async fault before going to suspend */ mte_suspend_enter(); @@ -103,12 +105,18 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) flags = local_daif_save(); /* - * Function graph tracer state gets incosistent when the kernel + * Function graph tracer state gets inconsistent when the kernel * calls functions that never return (aka suspend finishers) hence * disable graph tracing during their execution. */ pause_graph_tracing(); + /* + * Switch to using DAIF.IF instead of PMR in order to reliably + * resume if we're using pseudo-NMIs. + */ + arm_cpuidle_save_irq_context(&context); + if (__cpu_suspend_enter(&state)) { /* Call the suspend finisher */ ret = fn(arg); @@ -126,6 +134,8 @@ int cpu_suspend(unsigned long arg, int (*fn)(unsigned long)) RCU_NONIDLE(__cpu_suspend_exit()); } + arm_cpuidle_restore_irq_context(&context); + unpause_graph_tracing(); /* -- cgit v1.2.3