iommu/amd: Check if IOAPIC information is correct

When the IOAPIC information provided in the IVRS table is
not correct or not complete the system may not boot at all
when interrupt remapping is enabled. So check if this
information is correct and print out a firmware bug message
when it is not.

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

2 files changed, 25 insertions, 4 deletions

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 9f69b561f5db..e39f9dbf297b 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -42,7 +42,7 @@ config AMD_IOMMU
         select PCI_PRI
         select PCI_PASID
         select IOMMU_API
-        depends on X86_64 && PCI && ACPI
+        depends on X86_64 && PCI && ACPI && X86_IO_APIC
         ---help---
           With this option you can enable support for AMD IOMMU hardware in
           your system. An IOMMU is a hardware component which provides
diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 2d923fe7c2a1..f8a222b0ac3f 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -33,6 +33,7 @@
 #include <asm/gart.h>
 #include <asm/x86_init.h>
 #include <asm/iommu_table.h>
+#include <asm/io_apic.h>
 
 #include "amd_iommu_proto.h"
 #include "amd_iommu_types.h"
@@ -1575,6 +1576,23 @@ static void __init free_on_init_error(void)
 #endif
 }
 
+static bool __init check_ioapic_information(void)
+{
+        int idx;
+
+        for (idx = 0; idx < nr_ioapics; idx++) {
+                int id = mpc_ioapic_id(idx);
+
+                if (get_ioapic_devid(id) < 0) {
+                        pr_err(FW_BUG "AMD-Vi: IO-APIC[%d] not in IVRS table\n", id);
+                        pr_err("AMD-Vi: Disabling interrupt remapping due to BIOS Bug\n");
+                        return false;
+                }
+        }
+
+        return true;
+}
+
 /*
  * This is the hardware init function for AMD IOMMU in the system.
  * This function is called either from amd_iommu_init or from the interrupt
@@ -1661,9 +1679,6 @@ static int __init early_amd_iommu_init(void)
         if (amd_iommu_pd_alloc_bitmap == NULL)
                 goto out;
 
-        /* init the device table */
-        init_device_table();
-
         /*
          * let all alias entries point to itself
          */
@@ -1686,6 +1701,9 @@ static int __init early_amd_iommu_init(void)
         if (ret)
                 goto out;
 
+        if (amd_iommu_irq_remap)
+                amd_iommu_irq_remap = check_ioapic_information();
+
         if (amd_iommu_irq_remap) {
                 /*
                  * Interrupt remapping enabled, create kmem_cache for the
@@ -1709,6 +1727,9 @@ static int __init early_amd_iommu_init(void)
         if (ret)
                 goto out;
 
+        /* init the device table */
+        init_device_table();
+
 out:
         /* Don't leak any ACPI memory */
         early_acpi_os_unmap_memory((char __iomem *)ivrs_base, ivrs_size);