From 86cf898e1d0fca245173980e3897580db38569a8 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Mon, 9 Nov 2009 22:15:15 +0000 Subject: intel-iommu: Check for 'DMAR at zero' BIOS error earlier. Chris Wright has some patches which let us fall back to swiotlb nicely if IOMMU initialisation fails. But those are a bit much for 2.6.32. Instead, let's shift the check for the biggest problem, the HP and Acer BIOS bug which reports a DMAR at physical address zero. That one can actually be checked much earlier -- before we even admit to having detected an IOMMU in the first place. So the swiotlb init goes ahead as we want. Signed-off-by: David Woodhouse --- drivers/pci/dmar.c | 49 +++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 39 insertions(+), 10 deletions(-) diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c index 22b02c6df85..e5f8fc164fd 100644 --- a/drivers/pci/dmar.c +++ b/drivers/pci/dmar.c @@ -175,15 +175,6 @@ dmar_parse_one_drhd(struct acpi_dmar_header *header) int ret = 0; drhd = (struct acpi_dmar_hardware_unit *)header; - if (!drhd->address) { - /* Promote an attitude of violence to a BIOS engineer today */ - WARN(1, "Your BIOS is broken; DMAR reported at address zero!\n" - "BIOS vendor: %s; Ver: %s; Product Version: %s\n", - dmi_get_system_info(DMI_BIOS_VENDOR), - dmi_get_system_info(DMI_BIOS_VERSION), - dmi_get_system_info(DMI_PRODUCT_VERSION)); - return -ENODEV; - } dmaru = kzalloc(sizeof(*dmaru), GFP_KERNEL); if (!dmaru) return -ENOMEM; @@ -591,12 +582,50 @@ int __init dmar_table_init(void) return 0; } +int __init check_zero_address(void) +{ + struct acpi_table_dmar *dmar; + struct acpi_dmar_header *entry_header; + struct acpi_dmar_hardware_unit *drhd; + + dmar = (struct acpi_table_dmar *)dmar_tbl; + entry_header = (struct acpi_dmar_header *)(dmar + 1); + + while (((unsigned long)entry_header) < + (((unsigned long)dmar) + dmar_tbl->length)) { + /* Avoid looping forever on bad ACPI tables */ + if (entry_header->length == 0) { + printk(KERN_WARNING PREFIX + "Invalid 0-length structure\n"); + return 0; + } + + if (entry_header->type == ACPI_DMAR_TYPE_HARDWARE_UNIT) { + drhd = (void *)entry_header; + if (!drhd->address) { + /* Promote an attitude of violence to a BIOS engineer today */ + WARN(1, "Your BIOS is broken; DMAR reported at address zero!\n" + "BIOS vendor: %s; Ver: %s; Product Version: %s\n", + dmi_get_system_info(DMI_BIOS_VENDOR), + dmi_get_system_info(DMI_BIOS_VERSION), + dmi_get_system_info(DMI_PRODUCT_VERSION)); + return 0; + } + break; + } + + entry_header = ((void *)entry_header + entry_header->length); + } + return 1; +} + void __init detect_intel_iommu(void) { int ret; ret = dmar_table_detect(); - + if (ret) + ret = check_zero_address(); { #ifdef CONFIG_INTR_REMAP struct acpi_table_dmar *dmar; -- cgit v1.2.3