From patchwork Tue Jan 8 14:07:30 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Thierry X-Patchwork-Id: 10752117 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 B6AB46C5 for ; Tue, 8 Jan 2019 14:12:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A29E828C45 for ; Tue, 8 Jan 2019 14:12:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 96B8228CB4; Tue, 8 Jan 2019 14:12:55 +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 F37EE28C45 for ; Tue, 8 Jan 2019 14:12:54 +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=bd0kVqswMs+DqCpUKbn64iKi2sy7Ff1PimU2E6Ue6D8=; b=kx4WlljR1dE/zWS+X4JUw3TUrH AvFmY9m8gPQLOdG8KuhoXtvgHIhfCtroN8P3gzBuEzVIAc4fXFaEDoE5k7Z/NwDOlFmoaDWzGpdxP LWHoNXGgUvLHYvqeSgQfG2g8DXVeluizZC/jykMs/Ei37h0GOPAFrKFlNYPjumr0UcZWLu3FQMMSF zTzmE5TsB+4ToVZHvpps45FCxZ7VXn5yuNujCqLNa+joak87NUbfXlPKw9bzo8poIx16EM4bZQYcT iShOhE7Hmqsgstje0qp7gW5RaMbY4MbkJx+4BqsyRAwRmH9rIO9zADgFjKHyPbFB5rED8YwFS/t8Y xlIMBsAQ==; 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 1ggs7g-00059T-Ld; Tue, 08 Jan 2019 14:12:52 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1ggs3W-0007V2-RI for linux-arm-kernel@lists.infradead.org; Tue, 08 Jan 2019 14:09:08 +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 DA8DB19BF; Tue, 8 Jan 2019 06:08:25 -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 C3C133F70D; Tue, 8 Jan 2019 06:08:23 -0800 (PST) From: Julien Thierry To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v8 12/26] arm64: irqflags: Use ICC_PMR_EL1 for interrupt masking Date: Tue, 8 Jan 2019 14:07:30 +0000 Message-Id: <1546956464-48825-13-git-send-email-julien.thierry@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1546956464-48825-1-git-send-email-julien.thierry@arm.com> References: <1546956464-48825-1-git-send-email-julien.thierry@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190108_060835_508156_1B328A71 X-CRM114-Status: GOOD ( 16.32 ) 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 Cc: Catalin Marinas Cc: Will Deacon Cc: Ard Biesheuvel Cc: Oleg Nesterov --- arch/arm64/include/asm/efi.h | 11 ++++ arch/arm64/include/asm/irqflags.h | 123 +++++++++++++++++++++++++++++--------- 2 files changed, 106 insertions(+), 28 deletions(-) diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index 7ed3208..134ff6e 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) +#define arch_efi_save_flags(state_flags) \ + do { \ + (state_flags) = read_sysreg(daif); \ + } while (0) + +#define arch_efi_restore_flags(state_flags) \ + do { \ + write_sysreg(state_flags, daif); \ + } while (0) + + /* 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..fa3b06f 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 @@ -36,47 +38,96 @@ /* * 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"); } /* + * Having two ways to control interrupt status is a bit complicated. Some + * locations like exception entries will have PSR.I bit set by the architecture + * while PMR is unmasked. + * We need the irqflags to represent that interrupts are disabled in such cases. + * + * For this, we lower the value read from PMR when the I bit is set so it is + * considered as an irq masking priority. (With PMR, lower value means masking + * more interrupts). + */ +#define _get_irqflags(daif_bits, pmr) \ +({ \ + unsigned long flags; \ + \ + BUILD_BUG_ON(GIC_PRIO_IRQOFF < (GIC_PRIO_IRQON & ~PSR_I_BIT)); \ + asm volatile(ALTERNATIVE( \ + "mov %0, %1\n" \ + "nop\n" \ + "nop", \ + "and %0, %1, #" __stringify(PSR_I_BIT) "\n" \ + "mvn %0, %0\n" \ + "and %0, %0, %2", \ + ARM64_HAS_IRQ_PRIO_MASKING) \ + : "=&r" (flags) \ + : "r" (daif_bits), "r" (pmr) \ + : "memory"); \ + \ + flags; \ +}) + +/* * Save the current interrupt enable state. */ static inline unsigned long arch_local_save_flags(void) { - unsigned long flags; - asm volatile( - "mrs %0, daif // arch_local_save_flags" - : "=r" (flags) + unsigned long daif_bits; + unsigned long pmr; // Only used if alternative is on + + daif_bits = read_sysreg(daif); + + // Get PMR + asm volatile(ALTERNATIVE( + "nop", + "mrs_s %0, " __stringify(SYS_ICC_PMR_EL1), + ARM64_HAS_IRQ_PRIO_MASKING) + : "=&r" (pmr) : : "memory"); + + return _get_irqflags(daif_bits, pmr); +} + +#undef _get_irqflags + +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 +136,32 @@ 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