From patchwork Thu Sep 25 00:23:26 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Geoff Levand X-Patchwork-Id: 4971771 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 15D779FA52 for ; Thu, 25 Sep 2014 00:27:03 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id DF9C620279 for ; Thu, 25 Sep 2014 00:27:00 +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 1D3AC20274 for ; Thu, 25 Sep 2014 00:27:00 +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 1XWwrH-0001jq-5Z; Thu, 25 Sep 2014 00:24:31 +0000 Received: from merlin.infradead.org ([2001:4978:20e::2]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XWwqI-00016C-AA; Thu, 25 Sep 2014 00:23:30 +0000 Received: from geoff by merlin.infradead.org with local (Exim 4.80.1 #2 (Red Hat Linux)) id 1XWwqE-0001sd-Rc; Thu, 25 Sep 2014 00:23:26 +0000 Message-Id: <7109e9ce24c9349d40fb68c6b66e45d20ca9b26d.1411604443.git.geoff@infradead.org> In-Reply-To: References: From: Geoff Levand Patch-Date: Wed, 24 Sep 2014 17:18:31 -0700 Subject: [PATCH 3/7] arm64: Add new hcall HVC_CALL_FUNC To: Catalin Marinas , Will Deacon Date: Thu, 25 Sep 2014 00:23:26 +0000 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: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.6 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 | 17 ++++++++++++++--- 2 files changed, 27 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index 99c319c..055e8d8 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -41,6 +41,19 @@ #define HVC_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 8b39522..8dfb3a6 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -65,9 +65,20 @@ el1_sync: mrs x0, vbar_el2 b 2f -1: cmp x18, #HVC_SET_VECTORS - b.ne 2f - msr vbar_el2, x0 +1: cmp x18, #HVC_SET_VECTORS + b.ne 1f + msr vbar_el2, x0 + b 2f + +1: cmp x18, #HVC_CALL_FUNC + b.ne 2f + mov x18, lr + mov lr, x0 + mov x0, x1 + mov x1, x2 + mov x2, x3 + blr lr + mov lr, x18 2: eret ENDPROC(el1_sync)