From d35165a955f095095cdb8512cb7cd8f63101649a Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Sun, 9 Nov 2014 22:47:59 +0800 Subject: iommu/vt-d: Search for ACPI _DSM method for DMAR hotplug 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 Reviewed-by: Yijing Wang Signed-off-by: Joerg Roedel --- drivers/iommu/dmar.c | 33 ++++++++++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-) (limited to 'drivers/iommu/dmar.c') diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c index 0bd536d769a9..9847613085e1 100644 --- a/drivers/iommu/dmar.c +++ b/drivers/iommu/dmar.c @@ -1942,21 +1942,48 @@ static int dmar_hotplug_remove(acpi_handle handle) return ret; } +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; +} + static 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; -- cgit v1.2.3