From: Julien Thierry <julien.thierry@arm.com>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
Mark Rutland <mark.rutland@arm.com>,
Daniel Thompson <daniel.thompson@linaro.org>,
Marc Zyngier <marc.zyngier@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will.deacon@arm.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Christoffer Dall <christoffer.dall@arm.com>,
James Morse <james.morse@arm.com>,
Joel Fernandes <joel@joelfernandes.org>
Subject: Re: [PATCH v9 09/26] arm64: Unmask PMR before going idle
Date: Wed, 23 Jan 2019 08:56:20 +0000 [thread overview]
Message-ID: <6d9cd0ea-d487-bfb0-0461-1e0fcd24a7e1@arm.com> (raw)
In-Reply-To: <CAKv+Gu8qL1BWE-xXA+X0wrORBpv+tVKKOnN0Dv+FGQFZGWUB-w@mail.gmail.com>
On 22/01/2019 20:18, Ard Biesheuvel wrote:
> On Mon, 21 Jan 2019 at 16:36, Julien Thierry <julien.thierry@arm.com> wrote:
>>
>> CPU does not received signals for interrupts with a priority masked by
>> ICC_PMR_EL1. This means the CPU might not come back from a WFI
>> instruction.
>>
>> Make sure ICC_PMR_EL1 does not mask interrupts when doing a WFI.
>>
>> Since the logic of cpu_do_idle is becoming a bit more complex than just
>> two instructions, lets turn it from ASM to C.
>>
>> Signed-off-by: Julien Thierry <julien.thierry@arm.com>
>> Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
>> Cc: Catalin Marinas <catalin.marinas@arm.com>
>> Cc: Will Deacon <will.deacon@arm.com>
>> ---
>> arch/arm64/kernel/process.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
>> arch/arm64/mm/proc.S | 11 -----------
>> 2 files changed, 45 insertions(+), 11 deletions(-)
>>
>> diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
>> index 6d410fc..f05b63f 100644
>> --- a/arch/arm64/kernel/process.c
>> +++ b/arch/arm64/kernel/process.c
>> @@ -51,6 +51,7 @@
>> #include <linux/thread_info.h>
>>
>> #include <asm/alternative.h>
>> +#include <asm/arch_gicv3.h>
>> #include <asm/compat.h>
>> #include <asm/cacheflush.h>
>> #include <asm/exec.h>
>> @@ -74,6 +75,50 @@
>>
>> void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
>>
>> +static inline void __cpu_do_idle(void)
>> +{
>> + dsb(sy);
>> + wfi();
>> +}
>> +
>> +static inline void __cpu_do_idle_irqprio(void)
>
> Can we drop the 'inline's from all the function definitions in .c
> files? (not just in this patch)
> We tend to leave that to the compiler.
>
Sure, I guess cpu_do_idle() isn't a performance critical path anyway.
Unless anyone argues against it, I'll drop these inlines for the next
version.
Thanks,
Julien
>> +{
>> + unsigned long pmr;
>> + unsigned long daif_bits;
>> +
>> + daif_bits = read_sysreg(daif);
>> + write_sysreg(daif_bits | PSR_I_BIT, daif);
>> +
>> + /*
>> + * Unmask PMR before going idle to make sure interrupts can
>> + * be raised.
>> + */
>> + pmr = gic_read_pmr();
>> + gic_write_pmr(GIC_PRIO_IRQON);
>> +
>> + __cpu_do_idle();
>> +
>> + gic_write_pmr(pmr);
>> + write_sysreg(daif_bits, daif);
>> +}
>> +
>> +/*
>> + * cpu_do_idle()
>> + *
>> + * Idle the processor (wait for interrupt).
>> + *
>> + * If the CPU supports priority masking we must do additional work to
>> + * ensure that interrupts are not masked at the PMR (because the core will
>> + * not wake up if we block the wake up signal in the interrupt controller).
>> + */
>> +void cpu_do_idle(void)
>> +{
>> + if (system_uses_irq_prio_masking())
>> + __cpu_do_idle_irqprio();
>> + else
>> + __cpu_do_idle();
>> +}
>> +
>> /*
>> * This is our default idle handler.
>> */
>> diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
>> index 73886a5..3ea4f3b 100644
>> --- a/arch/arm64/mm/proc.S
>> +++ b/arch/arm64/mm/proc.S
>> @@ -55,17 +55,6 @@
>>
>> #define MAIR(attr, mt) ((attr) << ((mt) * 8))
>>
>> -/*
>> - * cpu_do_idle()
>> - *
>> - * Idle the processor (wait for interrupt).
>> - */
>> -ENTRY(cpu_do_idle)
>> - dsb sy // WFI may enter a low-power mode
>> - wfi
>> - ret
>> -ENDPROC(cpu_do_idle)
>> -
>> #ifdef CONFIG_CPU_PM
>> /**
>> * cpu_do_suspend - save CPU registers context
>> --
>> 1.9.1
>>
>>
>> _______________________________________________
>> linux-arm-kernel mailing list
>> linux-arm-kernel@lists.infradead.org
>> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
--
Julien Thierry
next prev parent reply other threads:[~2019-01-23 8:56 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-21 15:33 [PATCH v9 00/26] arm64: provide pseudo NMI with GICv3 Julien Thierry
2019-01-21 15:33 ` [PATCH v9 01/26] arm64: Fix HCR.TGE status for NMI contexts Julien Thierry
2019-01-28 11:48 ` James Morse
2019-01-28 15:42 ` Julien Thierry
2019-01-31 8:19 ` Christoffer Dall
2019-01-31 8:56 ` Julien Thierry
2019-01-31 9:27 ` Christoffer Dall
2019-01-31 9:40 ` Julien Thierry
2019-01-31 9:48 ` Christoffer Dall
2019-01-31 9:53 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 02/26] arm64: Remove unused daif related functions/macros Julien Thierry
2019-01-28 9:21 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 03/26] arm64: cpufeature: Set SYSREG_GIC_CPUIF as a boot system feature Julien Thierry
2019-01-28 9:22 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 04/26] arm64: cpufeature: Add cpufeature for IRQ priority masking Julien Thierry
2019-01-28 9:24 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 05/26] arm/arm64: gic-v3: Add PMR and RPR accessors Julien Thierry
2019-01-28 9:25 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 06/26] irqchip/gic-v3: Switch to PMR masking before calling IRQ handler Julien Thierry
2019-01-28 9:30 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 07/26] arm64: ptrace: Provide definitions for PMR values Julien Thierry
2019-01-28 9:37 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 08/26] arm64: Make PMR part of task context Julien Thierry
2019-01-28 9:42 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 09/26] arm64: Unmask PMR before going idle Julien Thierry
2019-01-22 15:23 ` Catalin Marinas
2019-01-22 20:18 ` Ard Biesheuvel
2019-01-23 8:56 ` Julien Thierry [this message]
2019-01-23 9:38 ` Ard Biesheuvel
2019-01-28 9:44 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 10/26] arm64: kvm: Unmask PMR before entering guest Julien Thierry
2019-01-28 9:58 ` Marc Zyngier
2019-01-30 12:07 ` Christoffer Dall
2019-01-30 14:58 ` Julien Thierry
2019-01-21 15:33 ` [PATCH v9 11/26] efi: Let architectures decide the flags that should be saved/restored Julien Thierry
2019-01-21 15:42 ` Ard Biesheuvel
2019-01-23 9:04 ` Julien Thierry
2019-01-28 10:00 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 12/26] arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking Julien Thierry
2019-01-21 15:45 ` Ard Biesheuvel
2019-01-21 18:05 ` Julien Thierry
2019-01-22 15:21 ` Catalin Marinas
2019-01-23 10:44 ` Julien Thierry
2019-01-30 11:52 ` Julien Thierry
2019-01-21 15:33 ` [PATCH v9 13/26] arm64: daifflags: Include PMR in daifflags restore operations Julien Thierry
2019-01-28 10:37 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 14/26] arm64: alternative: Allow alternative status checking per cpufeature Julien Thierry
2019-01-28 11:00 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 15/26] arm64: alternative: Apply alternatives early in boot process Julien Thierry
2019-01-28 11:17 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 16/26] irqchip/gic-v3: Factor group0 detection into functions Julien Thierry
2019-01-28 11:19 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 17/26] arm64: Switch to PMR masking when starting CPUs Julien Thierry
2019-01-28 11:21 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 18/26] arm64: gic-v3: Implement arch support for priority masking Julien Thierry
2019-01-28 11:23 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 19/26] irqchip/gic-v3: Detect if GIC can support pseudo-NMIs Julien Thierry
2019-01-28 11:39 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 20/26] irqchip/gic-v3: Handle pseudo-NMIs Julien Thierry
2019-01-28 11:59 ` Marc Zyngier
2019-01-29 11:33 ` Julien Thierry
2019-01-29 12:31 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 21/26] irqchip/gic: Add functions to access irq priorities Julien Thierry
2019-01-28 12:04 ` Marc Zyngier
2019-01-29 11:36 ` Julien Thierry
2019-01-21 15:33 ` [PATCH v9 22/26] irqchip/gic-v3: Allow interrupts to be set as pseudo-NMI Julien Thierry
2019-01-26 10:19 ` liwei (GF)
2019-01-26 10:41 ` Marc Zyngier
2019-01-28 8:57 ` Julien Thierry
2019-01-28 13:59 ` liwei (GF)
2019-01-28 14:49 ` Julien Thierry
2019-01-28 12:08 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 23/26] arm64: Handle serror in NMI context Julien Thierry
2019-01-28 12:26 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 24/26] arm64: Skip preemption when exiting an NMI Julien Thierry
2019-01-28 12:34 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 25/26] arm64: Skip irqflags tracing for NMI in IRQs disabled context Julien Thierry
2019-01-28 12:40 ` Marc Zyngier
2019-01-21 15:33 ` [PATCH v9 26/26] arm64: Enable the support of pseudo-NMIs Julien Thierry
2019-01-28 12:47 ` Marc Zyngier
2019-01-30 13:46 ` Julien Thierry
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