From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964845AbcFME1D (ORCPT ); Mon, 13 Jun 2016 00:27:03 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:41900 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964793AbcFME07 (ORCPT ); Mon, 13 Jun 2016 00:26:59 -0400 From: Sinan Kaya To: kvm@vger.kernel.org, timur@codeaurora.org, cov@codeaurora.org, jcm@redhat.com, alex.williamson@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 , linux-kernel@vger.kernel.org Subject: [PATCH V7 6/9] vfio: platform: call _RST method when using ACPI Date: Mon, 13 Jun 2016 00:26:38 -0400 Message-Id: <1465792001-27960-7-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1465792001-27960-1-git-send-email-okaya@codeaurora.org> References: <1465792001-27960-1-git-send-email-okaya@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 introduces two functions as vfio_platform_acpi_has_reset and vfio_platform_acpi_call_reset. The has reset method is used to declare reset capability via the ioctl flag VFIO_DEVICE_FLAGS_RESET. The call reset function is used to execute the _RST ACPI method. 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"); -- 1.8.2.1