From patchwork Thu Jan 31 14:58:50 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Thierry X-Patchwork-Id: 10790757 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 041D414E1 for ; Thu, 31 Jan 2019 15:02:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EA9CE31391 for ; Thu, 31 Jan 2019 15:02:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E8C3531392; Thu, 31 Jan 2019 15:02:48 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 62F8D3139B for ; Thu, 31 Jan 2019 15:02:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:MIME-Version:Cc:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:References: In-Reply-To:Message-Id:Date:Subject:To:From:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Owner; bh=+ngcZwGxDOC5wYbdG+wHDvJ4CdeA3eSBQ9LLNBvbKAg=; b=aYYP+a1Dd0CrqfMfXpuEMtHYGD FEwUHz0+bzcqKjOQBCH7m1f93wLbbP/9kuleOe4vurTCBbLLcRmM7Qwe+PAA5gC87D9DH5xb63kN1 4HBrq0ftFJPzCskhdRFyvWDZv8O3BWUJbTM6khnQoG4Sjxp7QwpegRwU6B+YhklQO0zBB0J+g8hl4 BleZNQVE9KeIwNVpp8gwhXmjtMON9+Bmoh9iV34ik3P6XGe1/hxDyqd7m6v9fRtSU5e5RYYEkStQi r7GySyV/AZ+2wLbMKEXFeUmc5pSAjjLvvxM07qASUGC2bEcu9IGIeL0MNul5ZpRaW4vKTtKKri14h kxVYTVHg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gpDra-0001dA-Q1; Thu, 31 Jan 2019 15:02:46 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gpDof-0006Tg-69 for linux-arm-kernel@lists.infradead.org; Thu, 31 Jan 2019 14:59:56 +0000 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 BAFC6EBD; Thu, 31 Jan 2019 06:59:44 -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 A77ED3F59C; Thu, 31 Jan 2019 06:59:42 -0800 (PST) From: Julien Thierry To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v10 12/25] arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking Date: Thu, 31 Jan 2019 14:58:50 +0000 Message-Id: <1548946743-38979-13-git-send-email-julien.thierry@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1548946743-38979-1-git-send-email-julien.thierry@arm.com> References: <1548946743-38979-1-git-send-email-julien.thierry@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190131_065945_484685_CED4F0F7 X-CRM114-Status: GOOD ( 15.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, daniel.thompson@linaro.org, Julien Thierry , marc.zyngier@arm.com, catalin.marinas@arm.com, Ard Biesheuvel , will.deacon@arm.com, linux-kernel@vger.kernel.org, christoffer.dall@arm.com, james.morse@arm.com, Oleg Nesterov , joel@joelfernandes.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP 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 Acked-by: Ard Biesheuvel Reviewed-by: Catalin Marinas Cc: Catalin Marinas Cc: Will Deacon Cc: Ard Biesheuvel Cc: Oleg Nesterov Tested-by: Nathan Chancellor --- arch/arm64/include/asm/efi.h | 11 +++++ arch/arm64/include/asm/irqflags.h | 100 +++++++++++++++++++++++++++----------- 2 files changed, 83 insertions(+), 28 deletions(-) diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index 7ed3208..c9e9a69 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -44,6 +44,17 @@ #define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT) +/* + * Even when Linux uses IRQ priorities for IRQ disabling, EFI does not. + * And EFI shouldn't really play around with priority masking as it is not aware + * which priorities the OS has assigned to its interrupts. + */ +#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..d4597b2 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 +38,27 @@ /* * 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" - : + 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" (GIC_PRIO_IRQON) : "memory"); } static inline void arch_local_irq_disable(void) { - asm volatile( - "msr daifset, #2 // arch_local_irq_disable" - : + asm volatile(ALTERNATIVE( + "msr daifset, #2 // arch_local_irq_disable", + "msr_s " __stringify(SYS_ICC_PMR_EL1) ", %0", + ARM64_HAS_IRQ_PRIO_MASKING) : + : "r" (GIC_PRIO_IRQOFF) : "memory"); } @@ -71,12 +67,44 @@ 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 +113,32 @@ 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