From patchwork Wed Sep 10 18:11:49 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geoff Levand X-Patchwork-Id: 4879551 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 2CDC19F32E for ; Wed, 10 Sep 2014 18:13:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5A250201BC for ; Wed, 10 Sep 2014 18:13:45 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7C2CE201B9 for ; Wed, 10 Sep 2014 18:13:44 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XRmN5-0006xi-0q; Wed, 10 Sep 2014 18:11:59 +0000 Received: from casper.infradead.org ([2001:770:15f::2]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XRmN1-0006vz-Nd; Wed, 10 Sep 2014 18:11:55 +0000 Received: from 107-1-141-74-ip-static.hfc.comcastbusiness.net ([107.1.141.74] helo=[192.168.254.170]) by casper.infradead.org with esmtpsa (Exim 4.80.1 #2 (Red Hat Linux)) id 1XRmMz-0002pc-C3; Wed, 10 Sep 2014 18:11:53 +0000 Message-ID: <1410372709.30895.0.camel@smoke> Subject: [PATCH V2 04/13] arm64: Add new hcall HVC_CALL_FUNC From: Geoff Levand To: Catalin Marinas , Will Deacon Date: Wed, 10 Sep 2014 11:11:49 -0700 In-Reply-To: References: X-Mailer: Evolution 3.10.4-0ubuntu2 Mime-Version: 1.0 Cc: marc.zyngier@arm.com, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org, christoffer.dall@linaro.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_NONE, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Add the new hcall HVC_CALL_FUNC that allows execution of a function at EL2. During CPU reset the CPU must be brought to the exception level it had on entry to the kernel. The HVC_CALL_FUNC hcall will provide the mechanism needed for this exception level switch. Signed-off-by: Geoff Levand --- arch/arm64/include/asm/virt.h | 13 +++++++++++++ arch/arm64/kernel/hyp-stub.S | 10 ++++++++++ 2 files changed, 23 insertions(+) diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index 894fe53..cc4250c 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -41,6 +41,19 @@ #define HVC_KVM_CALL_HYP 3 +/* + * HVC_CALL_FUNC - Execute a function at EL2. + * + * @x0: Physical address of the funtion to be executed. + * @x1: Passed as the first argument to the function. + * @x2: Passed as the second argument to the function. + * @x3: Passed as the third argument to the function. + * + * The called function must preserve the contents of register x18. + */ + +#define HVC_CALL_FUNC 4 + #ifndef __ASSEMBLY__ /* diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index 9ab5f70..27d786d 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -75,7 +75,17 @@ el1_sync: 1: cmp x10, #HVC_SET_VECTORS b.ne 1f msr vbar_el2, x0 + b 2f +1: cmp x10, #HVC_CALL_FUNC + b.ne 1f + mov x18, lr + mov lr, x0 + mov x0, x1 + mov x1, x2 + mov x2, x3 + blr lr + mov lr, x18 1: 2: eret ENDPROC(el1_sync)