From nobody Mon Feb 9 23:02:06 2026 Delivered-To: importer@patchew.org Received-SPF: none (zoho.com: 192.237.175.120 is neither permitted nor denied by domain of lists.xenproject.org) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; spf=none (zoho.com: 192.237.175.120 is neither permitted nor denied by domain of lists.xenproject.org) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org ARC-Seal: i=1; a=rsa-sha256; t=1560195230; cv=none; d=zoho.com; s=zohoarc; b=jyauK//oxpWf3HZF/pWrFB3M4rklCuQCa1jn6pt6pYa/y740/rgOlirXAFjqV4t/B8OTidIDLDzys2AHiuVu5EdnW5cjihwA3i3mZ89Nj5h4os0N0Yv676ru1JZkCZoIcJVxOwBLhOLdX9+aDxvnW7EdPoZBfjTY+s5vYCi6lKQ= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1560195230; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=/2efVw76EpIlAWOmz7Lpp+ufSJVO7tyorxPJ5n4UkVA=; b=BDbjw7juOVF/Wa95nm8oQUCC8E6NhYMqy9n0KnMcID5p1VN3R8xuykrcKq7yY0hKvlr+9naCv2qOaVDfKtA+TcyP6RtEWtTq3NOJwDn7v/WtvsH3UdjcxCtzNTE7q4jAbyBlu9vyizxoGUuJmuMKO45nFPYi/VBWwlOenaKIsyw= ARC-Authentication-Results: i=1; mx.zoho.com; spf=none (zoho.com: 192.237.175.120 is neither permitted nor denied by domain of lists.xenproject.org) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1560195230225747.6294569717884; Mon, 10 Jun 2019 12:33:50 -0700 (PDT) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1haQ1u-0007fE-Vf; Mon, 10 Jun 2019 19:32:30 +0000 Received: from us1-rack-dfw2.inumbo.com ([104.130.134.6]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1haQ1s-0007di-Ri for xen-devel@lists.xenproject.org; Mon, 10 Jun 2019 19:32:28 +0000 Received: from foss.arm.com (unknown [217.140.110.172]) by us1-rack-dfw2.inumbo.com (Halon) with ESMTP id 7b48ac70-8bb6-11e9-8980-bc764e045a96; Mon, 10 Jun 2019 19:32:28 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E5F4A344; Mon, 10 Jun 2019 12:32:27 -0700 (PDT) Received: from e108454-lin.cambridge.arm.com (e108454-lin.cambridge.arm.com [10.1.196.50]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0922F3F73C; Mon, 10 Jun 2019 12:32:26 -0700 (PDT) X-Inumbo-ID: 7b48ac70-8bb6-11e9-8980-bc764e045a96 From: Julien Grall To: xen-devel@lists.xenproject.org Date: Mon, 10 Jun 2019 20:32:05 +0100 Message-Id: <20190610193215.23704-8-julien.grall@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190610193215.23704-1-julien.grall@arm.com> References: <20190610193215.23704-1-julien.grall@arm.com> Subject: [Xen-devel] [PATCH 07/17] xen/arm64: head: Rework and document check_cpu_mode() X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: andre.przywara@arm.com, Julien Grall , Stefano Stabellini , andrii_anisov@epam.com, Oleksandr_Tyshchenko@epam.com MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" A branch in the success case can be avoided by inverting the branch condition. At the same time, remove a pointless comment as Xen can only run at EL2. Lastly, document the behavior and the main registers usage within the function. Signed-off-by: Julien Grall Reviewed-by: Stefano Stabellini --- xen/arch/arm/arm64/head.S | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/xen/arch/arm/arm64/head.S b/xen/arch/arm/arm64/head.S index ccd8a1b0a8..87fcd3be6c 100644 --- a/xen/arch/arm/arm64/head.S +++ b/xen/arch/arm/arm64/head.S @@ -350,6 +350,13 @@ secondary_switched: b launch ENDPROC(init_secondary) =20 +/* + * Check if the CPU has been booted in Hypervisor mode. + * This function will never return when the CPU is booted in another mode + * than Hypervisor mode. + * + * Clobbers x0 - x5 + */ check_cpu_mode: PRINT("- Current EL ") mrs x5, CurrentEL @@ -359,15 +366,13 @@ check_cpu_mode: /* Are we in EL2 */ cmp x5, #PSR_MODE_EL2t ccmp x5, #PSR_MODE_EL2h, #0x4, ne - b.eq el2 /* Yes */ - + b.ne 1f /* No */ + ret +1: /* OK, we're boned. */ PRINT("- Xen must be entered in NS EL2 mode -\r\n") PRINT("- Please update the bootloader -\r\n") b fail - -el2: PRINT("- Xen starting at EL2 -\r\n") - ret ENDPROC(check_cpu_mode) =20 zero_bss: --=20 2.11.0 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel