From patchwork Sat May 28 22:01:15 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sinan Kaya X-Patchwork-Id: 9139567 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2F5C460759 for ; Sat, 28 May 2016 22:03:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1FB7F20499 for ; Sat, 28 May 2016 22:03:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 148F726E82; Sat, 28 May 2016 22:03:10 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CE72F20499 for ; Sat, 28 May 2016 22:03:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752407AbcE1WCn (ORCPT ); Sat, 28 May 2016 18:02:43 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:43126 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751042AbcE1WBe (ORCPT ); Sat, 28 May 2016 18:01:34 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 204BA613CE; Sat, 28 May 2016 22:01:33 +0000 (UTC) Received: from drakthul.qualcomm.com (global_nat1_iad_fw.qualcomm.com [129.46.232.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: okaya@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 54C78613C8; Sat, 28 May 2016 22:01:31 +0000 (UTC) From: Sinan Kaya To: kvm@vger.kernel.org, timur@codeaurora.org, cov@codeaurora.org, jcm@redhat.com, eric.auger@linaro.org Cc: linux-acpi@vger.kernel.org, agross@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Sinan Kaya , Baptiste Reynal , Alex Williamson , linux-kernel@vger.kernel.org Subject: [PATCH V6 5/8] vfio: platform: call _RST method when using ACPI Date: Sat, 28 May 2016 18:01:15 -0400 Message-Id: <1464472878-27176-6-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1464472878-27176-1-git-send-email-okaya@codeaurora.org> References: <1464472878-27176-1-git-send-email-okaya@codeaurora.org> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The device tree code checks for the presence of a reset driver and calls the of_reset function pointer by looking up the reset driver as a module. ACPI defines _RST method to perform device level reset. After the _RST method is executed, the OS can resume using the device. _RST method is expected to stop DMA transfers and IRQs. This patch checks the presence of _RST method and calls the _RST method when reset is requested. Signed-off-by: Sinan Kaya Reviewed-by: Eric Auger --- drivers/vfio/platform/vfio_platform_common.c | 51 ++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index e7ce2c2..0ea8c26 100644 --- a/drivers/vfio/platform/vfio_platform_common.c +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -73,21 +73,66 @@ static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev, } return 0; } + +static int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev, + const char **extra_dbg) +{ + struct device *dev = vdev->device; + acpi_handle handle = ACPI_HANDLE(dev); + acpi_status acpi_ret; + unsigned long long val; + + acpi_ret = acpi_evaluate_integer(handle, "_RST", NULL, &val); + if (ACPI_FAILURE(acpi_ret)) { + if (extra_dbg) + *extra_dbg = acpi_format_exception(acpi_ret); + return -EINVAL; + } + + return 0; +} + +static bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev) +{ + struct device *dev = vdev->device; + acpi_handle handle = ACPI_HANDLE(dev); + + return acpi_has_method(handle, "_RST"); +} #else static inline int vfio_platform_acpi_probe(struct vfio_platform_device *vdev, struct device *dev) { return -ENOENT; } + +static inline +int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev, + const char **extra_dbg) +{ + return -ENOENT; +} + +static inline +bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev) +{ + return false; +} #endif static bool vfio_platform_has_reset(struct vfio_platform_device *vdev) { + if (vdev->acpihid) + return vfio_platform_acpi_has_reset(vdev); + return vdev->of_reset ? true : false; } static void vfio_platform_get_reset(struct vfio_platform_device *vdev) { + if (vdev->acpihid) + return; + vdev->of_reset = vfio_platform_lookup_reset(vdev->compat, &vdev->reset_module); if (!vdev->of_reset) { @@ -99,6 +144,9 @@ static void vfio_platform_get_reset(struct vfio_platform_device *vdev) static void vfio_platform_put_reset(struct vfio_platform_device *vdev) { + if (vdev->acpihid) + return; + if (vdev->of_reset) module_put(vdev->reset_module); } @@ -177,6 +225,9 @@ static int vfio_platform_call_reset(struct vfio_platform_device *vdev, if (vdev->of_reset) { dev_info(vdev->device, "reset\n"); return vdev->of_reset(vdev); + } else if (vdev->acpihid) { + dev_info(vdev->device, "reset\n"); + return vfio_platform_acpi_call_reset(vdev, extra_dbg); } dev_warn(vdev->device, "no reset function found!\n");