x86/amd-iommu: Add extended feature detection

This patch adds detection of the extended features of an
AMD IOMMU. The available features are printed to dmesg on
boot.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 22 insertions, 2 deletions

diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 8848dda808e..047905dc3e1 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -299,9 +299,23 @@ static void iommu_feature_disable(struct amd_iommu *iommu, u8 bit)
 /* Function to enable the hardware */
 static void iommu_enable(struct amd_iommu *iommu)
 {
-        printk(KERN_INFO "AMD-Vi: Enabling IOMMU at %s cap 0x%hx\n",
+        static const char * const feat_str[] = {
+                "PreF", "PPR", "X2APIC", "NX", "GT", "[5]",
+                "IA", "GA", "HE", "PC", NULL
+        };
+        int i;
+
+        printk(KERN_INFO "AMD-Vi: Enabling IOMMU at %s cap 0x%hx",
                dev_name(&iommu->dev->dev), iommu->cap_ptr);
 
+        if (iommu->cap & (1 << IOMMU_CAP_EFR)) {
+                printk(KERN_CONT " extended features: ");
+                for (i = 0; feat_str[i]; ++i)
+                        if (iommu_feature(iommu, (1ULL << i)))
+                                printk(KERN_CONT " %s", feat_str[i]);
+        }
+        printk(KERN_CONT "\n");
+
         iommu_feature_enable(iommu, CONTROL_IOMMU_EN);
 }
 
@@ -657,7 +671,7 @@ static void __init set_device_exclusion_range(u16 devid, struct ivmd_header *m)
 static void __init init_iommu_from_pci(struct amd_iommu *iommu)
 {
         int cap_ptr = iommu->cap_ptr;
-        u32 range, misc;
+        u32 range, misc, low, high;
         int i, j;
 
         pci_read_config_dword(iommu->dev, cap_ptr + MMIO_CAP_HDR_OFFSET,
@@ -673,6 +687,12 @@ static void __init init_iommu_from_pci(struct amd_iommu *iommu)
                                         MMIO_GET_LD(range));
         iommu->evt_msi_num = MMIO_MSI_NUM(misc);
 
+        /* read extended feature bits */
+        low  = readl(iommu->mmio_base + MMIO_EXT_FEATURES);
+        high = readl(iommu->mmio_base + MMIO_EXT_FEATURES + 4);
+
+        iommu->features = ((u64)high << 32) | low;
+
         if (!is_rd890_iommu(iommu->dev))
                 return;