Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 0815565a authored by David Woodhouse's avatar David Woodhouse
Browse files

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: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent cfc65dd5

drivers/pci/dmar.c

+18 −4
Original line number Diff line number Diff line
@@ -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,
@@ -675,6 +686,9 @@ int alloc_iommu(struct dmar_drhd_unit *drhd) 


	drhd->iommu = iommu;

	return 0;



 err_unmap:

	iounmap(iommu->reg);

 error:

	kfree(iommu);

	return -1;