From patchwork Thu Jan 31 14:58:51 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Thierry X-Patchwork-Id: 10790759 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 1C7A514E1 for ; Thu, 31 Jan 2019 15:03:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0AFC9312CE for ; Thu, 31 Jan 2019 15:03:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F278C3137E; Thu, 31 Jan 2019 15:03:01 +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 66D4331399 for ; Thu, 31 Jan 2019 15:03:01 +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=h6SI1eAlhyLp3kxcSF1FVBhqxx3/1I7u0dDABel2j0s=; b=BdpWnuK1ASl3hEKvKw406+RDIH vl7hvFLr12Qj255rrPRFn1JAcxpSURWsATS7woPo4ZnK+bK5aSRAwNzkroeSOF9JBx+vmtsOO2yD/ BbUZWp+gPo89mtzHeO7Y/Ock0IbwvteiWXuhCzPuNKs/vnXHlwMaXPuc3OHghM2XBygdrrIl6ylDW mkVH2Ul7gYKBdyJ8P2MkHcntsN4Ft4noLu5HRig7xIno3X0ezLbVYH1OBnQtBpDsVI41CP8vZGcgy utl39dyQZorits3FLW1bZhp/j8e/lPLszL/Lg+0QPAvgoj1SyXzngVkiOHeOCiPEoXDtWRTw2fqns y8rsCxPQ==; 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 1gpDrj-0001lp-RW; Thu, 31 Jan 2019 15:02:55 +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 1gpDoh-0006Vy-Dg 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 F350C80D; Thu, 31 Jan 2019 06:59:46 -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 062DE3F59C; Thu, 31 Jan 2019 06:59:44 -0800 (PST) From: Julien Thierry To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v10 13/25] arm64: daifflags: Include PMR in daifflags restore operations Date: Thu, 31 Jan 2019 14:58:51 +0000 Message-Id: <1548946743-38979-14-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_065948_341485_B1D9F25E X-CRM114-Status: GOOD ( 15.64 ) 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, will.deacon@arm.com, linux-kernel@vger.kernel.org, christoffer.dall@arm.com, james.morse@arm.com, 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 The addition of PMR should not bypass the semantics of daifflags. When DA_F are set, I bit is also set as no interrupts (even of higher priority) is allowed. When DA_F are cleared, I bit is cleared and interrupt enabling/disabling goes through ICC_PMR_EL1. Signed-off-by: Julien Thierry Reviewed-by: Catalin Marinas Reviewed-by: Marc Zyngier Cc: Catalin Marinas Cc: Will Deacon Cc: James Morse --- arch/arm64/include/asm/daifflags.h | 50 +++++++++++++++++++++++++++++++++++--- 1 file changed, 46 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/daifflags.h b/arch/arm64/include/asm/daifflags.h index 546bc39..1dd3d7a 100644 --- a/arch/arm64/include/asm/daifflags.h +++ b/arch/arm64/include/asm/daifflags.h @@ -18,6 +18,8 @@ #include +#include + #define DAIF_PROCCTX 0 #define DAIF_PROCCTX_NOIRQ PSR_I_BIT @@ -36,7 +38,13 @@ static inline unsigned long local_daif_save(void) { unsigned long flags; - flags = arch_local_save_flags(); + flags = read_sysreg(daif); + + if (system_uses_irq_prio_masking()) { + /* If IRQs are masked with PMR, reflect it in the flags */ + if (read_sysreg_s(SYS_ICC_PMR_EL1) <= GIC_PRIO_IRQOFF) + flags |= PSR_I_BIT; + } local_daif_mask(); @@ -45,12 +53,46 @@ static inline unsigned long local_daif_save(void) static inline void local_daif_restore(unsigned long flags) { - if (!arch_irqs_disabled_flags(flags)) + bool irq_disabled = flags & PSR_I_BIT; + + if (!irq_disabled) { trace_hardirqs_on(); - arch_local_irq_restore(flags); + if (system_uses_irq_prio_masking()) + arch_local_irq_enable(); + } else if (!(flags & PSR_A_BIT)) { + /* + * If interrupts are disabled but we can take + * asynchronous errors, we can take NMIs + */ + if (system_uses_irq_prio_masking()) { + flags &= ~PSR_I_BIT; + /* + * There has been concern that the write to daif + * might be reordered before this write to PMR. + * From the ARM ARM DDI 0487D.a, section D1.7.1 + * "Accessing PSTATE fields": + * Writes to the PSTATE fields have side-effects on + * various aspects of the PE operation. All of these + * side-effects are guaranteed: + * - Not to be visible to earlier instructions in + * the execution stream. + * - To be visible to later instructions in the + * execution stream + * + * Also, writes to PMR are self-synchronizing, so no + * interrupts with a lower priority than PMR is signaled + * to the PE after the write. + * + * So we don't need additional synchronization here. + */ + arch_local_irq_disable(); + } + } + + write_sysreg(flags, daif); - if (arch_irqs_disabled_flags(flags)) + if (irq_disabled) trace_hardirqs_off(); }