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authorGerald Schaefer <gerald.schaefer@de.ibm.com>2015-11-16 14:35:48 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2015-11-27 09:24:15 +0100
commit69eea95c48857c9dfcac120d6acea43027627b28 (patch)
treeca93e959a34a2551e4aa1fb71d1487d8d28273f3 /arch/s390/pci/pci_dma.c
parents390: get_user_pages_fast() might sleep (diff)
downloadlinux-69eea95c48857c9dfcac120d6acea43027627b28.tar.xz
linux-69eea95c48857c9dfcac120d6acea43027627b28.zip
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>
Diffstat (limited to 'arch/s390/pci/pci_dma.c')
-rw-r--r--arch/s390/pci/pci_dma.c19
1 files changed, 14 insertions, 5 deletions
diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index d348f2c09a1e..3a40f718baef 100644
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -458,7 +458,19 @@ int zpci_dma_init_device(struct zpci_dev *zdev)
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 @@ int zpci_dma_init_device(struct zpci_dev *zdev)
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;