From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751618AbcGNCIE (ORCPT ); Wed, 13 Jul 2016 22:08:04 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:53365 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751170AbcGNCG4 (ORCPT ); Wed, 13 Jul 2016 22:06:56 -0400 From: Sinan Kaya To: kvm@vger.kernel.org, timur@codeaurora.org, cov@codeaurora.org, jcm@redhat.com, alex.williamson@redhat.com, eric.auger@redhat.com 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 V9 6/9] vfio: platform: call _RST method when using ACPI Date: Wed, 13 Jul 2016 22:06:32 -0400 Message-Id: <1468461995-32676-7-git-send-email-okaya@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1468461995-32676-1-git-send-email-okaya@codeaurora.org> References: <1468461995-32676-1-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 --- drivers/vfio/platform/vfio_platform_common.c | 52 +++++++++++++++++++++++++++- 1 file changed, 51 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index 03483c2..2d9c905 100644 --- a/drivers/vfio/platform/vfio_platform_common.c +++ b/drivers/vfio/platform/vfio_platform_common.c @@ -28,6 +28,8 @@ #define DRIVER_AUTHOR "Antonios Motakis " #define DRIVER_DESC "VFIO platform base module" +#define VFIO_PLATFORM_IS_ACPI(vdev) ((vdev)->acpihid != NULL) + static LIST_HEAD(reset_list); static DEFINE_MUTEX(driver_lock); @@ -77,13 +79,55 @@ static int vfio_platform_acpi_probe(struct vfio_platform_device *vdev, #endif } +static inline +int vfio_platform_acpi_call_reset(struct vfio_platform_device *vdev, + const char **extra_dbg) +{ +#ifdef CONFIG_ACPI + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + struct device *dev = vdev->device; + acpi_handle handle = ACPI_HANDLE(dev); + acpi_status acpi_ret; + + acpi_ret = acpi_evaluate_object(handle, "_RST", NULL, &buffer); + if (ACPI_FAILURE(acpi_ret)) { + if (extra_dbg) + *extra_dbg = acpi_format_exception(acpi_ret); + return -EINVAL; + } + + return 0; +#else + return -ENOENT; +#endif +} + +static inline +bool vfio_platform_acpi_has_reset(struct vfio_platform_device *vdev) +{ +#ifdef CONFIG_ACPI + struct device *dev = vdev->device; + acpi_handle handle = ACPI_HANDLE(dev); + + return acpi_has_method(handle, "_RST"); +#else + return false; +#endif +} + static bool vfio_platform_has_reset(struct vfio_platform_device *vdev) { + if (VFIO_PLATFORM_IS_ACPI(vdev)) + 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 (VFIO_PLATFORM_IS_ACPI(vdev)) + return; + vdev->of_reset = vfio_platform_lookup_reset(vdev->compat, &vdev->reset_module); if (!vdev->of_reset) { @@ -95,6 +139,9 @@ static void vfio_platform_get_reset(struct vfio_platform_device *vdev) static void vfio_platform_put_reset(struct vfio_platform_device *vdev) { + if (VFIO_PLATFORM_IS_ACPI(vdev)) + return; + if (vdev->of_reset) module_put(vdev->reset_module); } @@ -170,7 +217,10 @@ static void vfio_platform_regions_cleanup(struct vfio_platform_device *vdev) static int vfio_platform_call_reset(struct vfio_platform_device *vdev, const char **extra_dbg) { - if (vdev->of_reset) { + if (VFIO_PLATFORM_IS_ACPI(vdev)) { + dev_info(vdev->device, "reset\n"); + return vfio_platform_acpi_call_reset(vdev, extra_dbg); + } else if (vdev->of_reset) { dev_info(vdev->device, "reset\n"); return vdev->of_reset(vdev); } -- 1.8.2.1