[PATCH 15/28] iommu/amd: Check if IOAPIC information is correct

[Joerg Roedel]

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@xxxxxxx>
---
 drivers/iommu/amd_iommu_init.c |   26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/amd_iommu_init.c b/drivers/iommu/amd_iommu_init.c
index 9dc0ebc..ed4e690 100644
--- a/drivers/iommu/amd_iommu_init.c
+++ b/drivers/iommu/amd_iommu_init.c
@@ -1578,6 +1578,23 @@ 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
@@ -1664,9 +1681,6 @@ 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
 	 */
@@ -1689,6 +1703,9 @@ 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
@@ -1712,6 +1729,9 @@ 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 *)ivrs_base, ivrs_size);
-- 
1.7.9.5


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