iommu/amd: Extend IVRS special device data structure

This patch extends the devid_map data structure to allow
ioapic and hpet entries in ivrs to be overridden on the
kernel command line.

Reviewed-by: Shuah Khan <shuahkhan@gmail.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>

2 files changed, 21 insertions, 10 deletions

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index ea94ee644989..3a210f0c1b3f 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -703,25 +703,35 @@ static void __init set_dev_entry_from_acpi(struct amd_iommu *iommu,
         set_iommu_for_device(iommu, devid);
 }
 
-static int __init add_special_device(u8 type, u8 id, u16 devid)
+static int __init add_special_device(u8 type, u8 id, u16 devid, bool cmd_line)
 {
         struct devid_map *entry;
         struct list_head *list;
 
-        if (type != IVHD_SPECIAL_IOAPIC && type != IVHD_SPECIAL_HPET)
+        if (type == IVHD_SPECIAL_IOAPIC)
+                list = &ioapic_map;
+        else if (type == IVHD_SPECIAL_HPET)
+                list = &hpet_map;
+        else
                 return -EINVAL;
 
+        list_for_each_entry(entry, list, list) {
+                if (!(entry->id == id && entry->cmd_line))
+                        continue;
+
+                pr_info("AMD-Vi: Command-line override present for %s id %d - ignoring\n",
+                        type == IVHD_SPECIAL_IOAPIC ? "IOAPIC" : "HPET", id);
+
+                return 0;
+        }
+
         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
         if (!entry)
                 return -ENOMEM;
 
-        entry->id    = id;
-        entry->devid = devid;
-
-        if (type == IVHD_SPECIAL_IOAPIC)
-                list = &ioapic_map;
-        else
-                list = &hpet_map;
+        entry->id       = id;
+        entry->devid    = devid;
+        entry->cmd_line = cmd_line;
 
         list_add_tail(&entry->list, list);
 
@@ -929,7 +939,7 @@ static int __init init_iommu_from_acpi(struct amd_iommu *iommu,
                                     PCI_FUNC(devid));
 
                         set_dev_entry_from_acpi(iommu, devid, e->flags, 0);
-                        ret = add_special_device(type, handle, devid);
+                        ret = add_special_device(type, handle, devid, false);
                         if (ret)
                                 return ret;
                         break;
diff --git a/drivers/iommu/amd_iommu_types.h b/drivers/iommu/amd_iommu_types.h
index 083f98c0488b..b81153fb9e60 100644
--- a/drivers/iommu/amd_iommu_types.h
+++ b/drivers/iommu/amd_iommu_types.h
@@ -592,6 +592,7 @@ struct devid_map {
         struct list_head list;
         u8 id;
         u16 devid;
+        bool cmd_line;
 };
 
 /* Map HPET and IOAPIC ids to the devid used by the IOMMU */