s390/pci_dma: fix DMA table corruption with > 4 TB main memory
DMA addresses returned from map_page() are calculated by using an iommu
bitmap plus a start_dma offset. The size of this bitmap is based on the main
memory size. If we have more than (4 TB - start_dma) main memory, the DMA
address calculation will also produce addresses > 4 TB. Such addresses
cannot be inserted in the 3-level DMA page table, instead the entries
modulo 4 TB will be overwritten.
Fix this by restricting the iommu bitmap size to (4 TB - start_dma).
Also set zdev->end_dma to the actual end address of the usable
range, instead of the theoretical maximum as reported by the hardware,
which fixes a sanity check in dma_map() and also the IOMMU API domain
geometry aperture calculation.
Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/pci_dma.h b/arch/s390/include/asm/pci_dma.h
index 1aac41e..92df3eb 100644
--- a/arch/s390/include/asm/pci_dma.h
+++ b/arch/s390/include/asm/pci_dma.h
@@ -23,6 +23,8 @@
#define ZPCI_IOTA_FS_2G 2
#define ZPCI_KEY (PAGE_DEFAULT_KEY << 5)
+#define ZPCI_TABLE_SIZE_RT (1UL << 42)
+
#define ZPCI_IOTA_STO_FLAG (ZPCI_IOTA_IOT_ENABLED | ZPCI_KEY | ZPCI_IOTA_DT_ST)
#define ZPCI_IOTA_RTTO_FLAG (ZPCI_IOTA_IOT_ENABLED | ZPCI_KEY | ZPCI_IOTA_DT_RT)
#define ZPCI_IOTA_RSTO_FLAG (ZPCI_IOTA_IOT_ENABLED | ZPCI_KEY | ZPCI_IOTA_DT_RS)
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 7ef12a3..11d4f27 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -701,8 +701,7 @@
goto out;
zpci_map_resources(pdev);
- zpci_register_ioat(zdev, 0, zdev->start_dma + PAGE_OFFSET,
- zdev->start_dma + zdev->iommu_size - 1,
+ zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
(u64) zdev->dma_table);
out:
diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index d348f2c..3a40f71 100644
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -458,7 +458,19 @@
goto out_clean;
}
- zdev->iommu_size = (unsigned long) high_memory - PAGE_OFFSET;
+ /*
+ * Restrict the iommu bitmap size to the minimum of the following:
+ * - main memory size
+ * - 3-level pagetable address limit minus start_dma offset
+ * - DMA address range allowed by the hardware (clp query pci fn)
+ *
+ * Also set zdev->end_dma to the actual end address of the usable
+ * range, instead of the theoretical maximum as reported by hardware.
+ */
+ zdev->iommu_size = min3((u64) high_memory,
+ ZPCI_TABLE_SIZE_RT - zdev->start_dma,
+ zdev->end_dma - zdev->start_dma + 1);
+ zdev->end_dma = zdev->start_dma + zdev->iommu_size - 1;
zdev->iommu_pages = zdev->iommu_size >> PAGE_SHIFT;
zdev->iommu_bitmap = vzalloc(zdev->iommu_pages / 8);
if (!zdev->iommu_bitmap) {
@@ -466,10 +478,7 @@
goto out_reg;
}
- rc = zpci_register_ioat(zdev,
- 0,
- zdev->start_dma + PAGE_OFFSET,
- zdev->start_dma + zdev->iommu_size - 1,
+ rc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
(u64) zdev->dma_table);
if (rc)
goto out_reg;