From 0815565adfe3f4c369110c57d8ffe83caefeed68 Mon Sep 17 00:00:00 2001 From: David Woodhouse Date: Tue, 4 Aug 2009 09:17:20 +0100 Subject: [PATCH] intel-iommu: Cope with broken HP DC7900 BIOS Yet another reason why trusting this stuff to the BIOS was a bad idea. The HP DC7900 BIOS reports an iommu at an address which just returns all ones, when VT-d is disabled in the BIOS. Fix up the missing iounmap in the error paths while we're at it. Signed-off-by: David Woodhouse --- drivers/pci/dmar.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) diff --git a/drivers/pci/dmar.c b/drivers/pci/dmar.c index 7b287cb..380b60e 100644 --- a/drivers/pci/dmar.c +++ b/drivers/pci/dmar.c @@ -632,20 +632,31 @@ int alloc_iommu(struct dmar_drhd_unit *drhd) iommu->cap = dmar_readq(iommu->reg + DMAR_CAP_REG); iommu->ecap = dmar_readq(iommu->reg + DMAR_ECAP_REG); + if (iommu->cap == (uint64_t)-1 && iommu->ecap == (uint64_t)-1) { + /* Promote an attitude of violence to a BIOS engineer today */ + WARN(1, "Your BIOS is broken; DMAR reported at address %llx returns all ones!\n" + "BIOS vendor: %s; Ver: %s; Product Version: %s\n", + drhd->reg_base_addr, + dmi_get_system_info(DMI_BIOS_VENDOR), + dmi_get_system_info(DMI_BIOS_VERSION), + dmi_get_system_info(DMI_PRODUCT_VERSION)); + goto err_unmap; + } + #ifdef CONFIG_DMAR agaw = iommu_calculate_agaw(iommu); if (agaw < 0) { printk(KERN_ERR "Cannot get a valid agaw for iommu (seq_id = %d)\n", iommu->seq_id); - goto error; + goto err_unmap; } msagaw = iommu_calculate_max_sagaw(iommu); if (msagaw < 0) { printk(KERN_ERR "Cannot get a valid max agaw for iommu (seq_id = %d)\n", iommu->seq_id); - goto error; + goto err_unmap; } #endif iommu->agaw = agaw; @@ -665,7 +676,7 @@ int alloc_iommu(struct dmar_drhd_unit *drhd) } ver = readl(iommu->reg + DMAR_VER_REG); - pr_debug("IOMMU %llx: ver %d:%d cap %llx ecap %llx\n", + pr_info("IOMMU %llx: ver %d:%d cap %llx ecap %llx\n", (unsigned long long)drhd->reg_base_addr, DMAR_VER_MAJOR(ver), DMAR_VER_MINOR(ver), (unsigned long long)iommu->cap, @@ -675,7 +686,10 @@ int alloc_iommu(struct dmar_drhd_unit *drhd) drhd->iommu = iommu; return 0; -error: + + err_unmap: + iounmap(iommu->reg); + error: kfree(iommu); return -1; } -- 2.7.4