The patch titled drivers/pci/intel-iommu.c: return early if all dmar HW unit ignored has been added to the -mm tree. Its filename is drivers-pci-intel-iommuc-return-early-if-all-dmar-hw-unit-ignored.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: drivers/pci/intel-iommu.c: return early if all dmar HW unit ignored From: Luming Yu <luming.yu@xxxxxxxxx> When debugging an IOMMU problem, I noticed it would be much more safe to return early than late if all remapping HW unit are ignored. To figure out what device causes the iommu problem on my linux box: hp-compaq dc7800, I tried to mark all dmar HW unit ignored,but still got a lot of unxepcted dmar_fault. So I think the proposed patch make sense. The next step is to add a boot option to make dmar HW units selectable enable/disable individually. Signed-off-by: Yu Luming <luming.yu@xxxxxxxxx> Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx> Cc: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> Cc: Joerg Roedel <joerg.roedel@xxxxxxx> Cc: Weidong Han <weidong.han@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/pci/intel-iommu.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-) diff -puN drivers/pci/intel-iommu.c~drivers-pci-intel-iommuc-return-early-if-all-dmar-hw-unit-ignored drivers/pci/intel-iommu.c --- a/drivers/pci/intel-iommu.c~drivers-pci-intel-iommuc-return-early-if-all-dmar-hw-unit-ignored +++ a/drivers/pci/intel-iommu.c @@ -3002,9 +3002,10 @@ static void __init iommu_exit_mempool(vo } -static void __init init_no_remapping_devices(void) +static int __init init_no_remapping_devices(void) { struct dmar_drhd_unit *drhd; + int drhd_total = 0,drhd_ignored = 0; for_each_drhd_unit(drhd) { if (!drhd->include_all) { @@ -3016,32 +3017,34 @@ static void __init init_no_remapping_dev if (i == drhd->devices_cnt) drhd->ignored = 1; } + drhd_total++; } - - if (dmar_map_gfx) - return; - for_each_drhd_unit(drhd) { int i; - if (drhd->ignored || drhd->include_all) + if (drhd->ignored) + drhd_ignored++; + if (drhd->ignored || drhd->include_all) { + continue; + } + if (dmar_map_gfx) continue; - for (i = 0; i < drhd->devices_cnt; i++) if (drhd->devices[i] && !IS_GFX_DEVICE(drhd->devices[i])) break; - if (i < drhd->devices_cnt) continue; /* bypass IOMMU if it is just for gfx devices */ drhd->ignored = 1; + drhd_ignored++; for (i = 0; i < drhd->devices_cnt; i++) { if (!drhd->devices[i]) continue; drhd->devices[i]->dev.archdata.iommu = DUMMY_DEVICE_DOMAIN_INFO; } } + return (drhd_total == drhd_ignored); } #ifdef CONFIG_SUSPEND @@ -3208,7 +3211,12 @@ int __init intel_iommu_init(void) iommu_init_mempool(); dmar_init_reserved_ranges(); - init_no_remapping_devices(); + if(init_no_remapping_devices()) { + printk(KERN_ERR "IOMMU: all dmar HW unit ignored\n"); + put_iova_domain(&reserved_iova_list); + iommu_exit_mempool(); + return ret; + } ret = init_dmars(); if (ret) { _ Patches currently in -mm which might be from luming.yu@xxxxxxxxx are drivers-pci-intel-iommuc-return-early-if-all-dmar-hw-unit-ignored.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html