From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Jiang Liu To: Joerg Roedel , David Woodhouse , Yinghai Lu , Bjorn Helgaas , Dan Williams , Vinod Koul , "Rafael J . Wysocki" Cc: Jiang Liu , Ashok Raj , Yijing Wang , Tony Luck , iommu@lists.linux-foundation.org, linux-pci@vger.kernel.org, linux-hotplug@vger.kernel.org, linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org Subject: [Patch Part3 V4 17/21] iommu/vt-d: Search for ACPI _DSM method for DMAR hotplug Date: Fri, 11 Jul 2014 14:19:41 +0800 Message-Id: <1405059585-10620-18-git-send-email-jiang.liu@linux.intel.com> In-Reply-To: <1405059585-10620-1-git-send-email-jiang.liu@linux.intel.com> References: <1405059585-10620-1-git-send-email-jiang.liu@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: According to Intel VT-d specification, _DSM method to support DMAR hotplug should exist directly under corresponding ACPI object representing PCI host bridge. But some BIOSes doesn't conform to this, so search for _DSM method in the subtree starting from the ACPI object representing the PCI host bridge. Signed-off-by: Jiang Liu --- drivers/iommu/dmar.c | 35 +++++++++++++++++++++++++++++++---- 1 file changed, 31 insertions(+), 4 deletions(-) diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c index 9d8f5c82b717..cc1d19c33486 100644 --- a/drivers/iommu/dmar.c +++ b/drivers/iommu/dmar.c @@ -1927,21 +1927,48 @@ static int dmar_hotplug_remove(acpi_handle handle) return ret; } -static int dmar_device_hotplug(acpi_handle handle, bool insert) +static acpi_status dmar_get_dsm_handle(acpi_handle handle, u32 lvl, + void *context, void **retval) +{ + acpi_handle *phdl = retval; + + if (dmar_detect_dsm(handle, DMAR_DSM_FUNC_DRHD)) { + *phdl = handle; + return AE_CTRL_TERMINATE; + } + + return AE_OK; +} + +int dmar_device_hotplug(acpi_handle handle, bool insert) { int ret; + acpi_handle tmp = NULL; + acpi_status status; if (!dmar_in_use()) return 0; - if (!dmar_detect_dsm(handle, DMAR_DSM_FUNC_DRHD)) + if (dmar_detect_dsm(handle, DMAR_DSM_FUNC_DRHD)) { + tmp = handle; + } else { + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, + ACPI_UINT32_MAX, + dmar_get_dsm_handle, + NULL, NULL, &tmp); + if (ACPI_FAILURE(status)) { + pr_warn("Failed to locate _DSM method.\n"); + return -ENXIO; + } + } + if (tmp == NULL) return 0; down_write(&dmar_global_lock); if (insert) - ret = dmar_hotplug_insert(handle); + ret = dmar_hotplug_insert(tmp); else - ret = dmar_hotplug_remove(handle); + ret = dmar_hotplug_remove(tmp); up_write(&dmar_global_lock); return ret; -- 1.7.10.4