From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9C91DC2F42E for ; Mon, 21 Jan 2019 15:36:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 769B82085A for ; Mon, 21 Jan 2019 15:36:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730738AbfAUPg3 (ORCPT ); Mon, 21 Jan 2019 10:36:29 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:36514 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730189AbfAUPe3 (ORCPT ); Mon, 21 Jan 2019 10:34:29 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 5D26315BE; Mon, 21 Jan 2019 07:34:29 -0800 (PST) Received: from e112298-lin.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 49A373F5C1; Mon, 21 Jan 2019 07:34:27 -0800 (PST) From: Julien Thierry To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, daniel.thompson@linaro.org, joel@joelfernandes.org, marc.zyngier@arm.com, christoffer.dall@arm.com, james.morse@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, mark.rutland@arm.com, Julien Thierry , Ard Biesheuvel , Oleg Nesterov Subject: [PATCH v9 12/26] arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking Date: Mon, 21 Jan 2019 15:33:31 +0000 Message-Id: <1548084825-8803-13-git-send-email-julien.thierry@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1548084825-8803-1-git-send-email-julien.thierry@arm.com> References: <1548084825-8803-1-git-send-email-julien.thierry@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Instead disabling interrupts by setting the PSR.I bit, use a priority higher than the one used for interrupts to mask them via PMR. When using PMR to disable interrupts, the value of PMR will be used instead of PSR.[DAIF] for the irqflags. Signed-off-by: Julien Thierry Suggested-by: Daniel Thompson Cc: Catalin Marinas Cc: Will Deacon Cc: Ard Biesheuvel Cc: Oleg Nesterov --- arch/arm64/include/asm/efi.h | 6 +++ arch/arm64/include/asm/irqflags.h | 104 ++++++++++++++++++++++++++++---------- 2 files changed, 82 insertions(+), 28 deletions(-) diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index 7ed3208..3db6772 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -44,6 +44,12 @@ #define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT) +#define arch_efi_save_flags(state_flags) \ + ((void)((state_flags) = read_sysreg(daif))) + +#define arch_efi_restore_flags(state_flags) write_sysreg(state_flags, daif) + + /* arch specific definitions used by the stub code */ /* diff --git a/arch/arm64/include/asm/irqflags.h b/arch/arm64/include/asm/irqflags.h index 24692ed..7e82a92 100644 --- a/arch/arm64/include/asm/irqflags.h +++ b/arch/arm64/include/asm/irqflags.h @@ -18,7 +18,9 @@ #ifdef __KERNEL__ +#include #include +#include /* * Aarch64 has flags for masking: Debug, Asynchronous (serror), Interrupts and @@ -36,33 +38,31 @@ /* * CPU interrupt mask handling. */ -static inline unsigned long arch_local_irq_save(void) -{ - unsigned long flags; - asm volatile( - "mrs %0, daif // arch_local_irq_save\n" - "msr daifset, #2" - : "=r" (flags) - : - : "memory"); - return flags; -} - static inline void arch_local_irq_enable(void) { - asm volatile( - "msr daifclr, #2 // arch_local_irq_enable" - : + unsigned long unmasked = GIC_PRIO_IRQON; + + asm volatile(ALTERNATIVE( + "msr daifclr, #2 // arch_local_irq_enable\n" + "nop", + "msr_s " __stringify(SYS_ICC_PMR_EL1) ",%0\n" + "dsb sy", + ARM64_HAS_IRQ_PRIO_MASKING) : + : "r" (unmasked) : "memory"); } static inline void arch_local_irq_disable(void) { - asm volatile( - "msr daifset, #2 // arch_local_irq_disable" - : + unsigned long masked = GIC_PRIO_IRQOFF; + + asm volatile(ALTERNATIVE( + "msr daifset, #2 // arch_local_irq_disable", + "msr_s " __stringify(SYS_ICC_PMR_EL1) ", %0", + ARM64_HAS_IRQ_PRIO_MASKING) : + : "r" (masked) : "memory"); } @@ -71,12 +71,44 @@ static inline void arch_local_irq_disable(void) */ static inline unsigned long arch_local_save_flags(void) { + unsigned long daif_bits; unsigned long flags; - asm volatile( - "mrs %0, daif // arch_local_save_flags" - : "=r" (flags) - : + + daif_bits = read_sysreg(daif); + + /* + * The asm is logically equivalent to: + * + * if (system_uses_irq_prio_masking()) + * flags = (daif_bits & PSR_I_BIT) ? + * GIC_PRIO_IRQOFF : + * read_sysreg_s(SYS_ICC_PMR_EL1); + * else + * flags = daif_bits; + */ + asm volatile(ALTERNATIVE( + "mov %0, %1\n" + "nop\n" + "nop", + "mrs_s %0, " __stringify(SYS_ICC_PMR_EL1) "\n" + "ands %1, %1, " __stringify(PSR_I_BIT) "\n" + "csel %0, %0, %2, eq", + ARM64_HAS_IRQ_PRIO_MASKING) + : "=&r" (flags), "+r" (daif_bits) + : "r" (GIC_PRIO_IRQOFF) : "memory"); + + return flags; +} + +static inline unsigned long arch_local_irq_save(void) +{ + unsigned long flags; + + flags = arch_local_save_flags(); + + arch_local_irq_disable(); + return flags; } @@ -85,16 +117,32 @@ static inline unsigned long arch_local_save_flags(void) */ static inline void arch_local_irq_restore(unsigned long flags) { - asm volatile( - "msr daif, %0 // arch_local_irq_restore" - : - : "r" (flags) - : "memory"); + asm volatile(ALTERNATIVE( + "msr daif, %0\n" + "nop", + "msr_s " __stringify(SYS_ICC_PMR_EL1) ", %0\n" + "dsb sy", + ARM64_HAS_IRQ_PRIO_MASKING) + : "+r" (flags) + : + : "memory"); } static inline int arch_irqs_disabled_flags(unsigned long flags) { - return flags & PSR_I_BIT; + int res; + + asm volatile(ALTERNATIVE( + "and %w0, %w1, #" __stringify(PSR_I_BIT) "\n" + "nop", + "cmp %w1, #" __stringify(GIC_PRIO_IRQOFF) "\n" + "cset %w0, ls", + ARM64_HAS_IRQ_PRIO_MASKING) + : "=&r" (res) + : "r" ((int) flags) + : "memory"); + + return res; } #endif #endif -- 1.9.1