From 69eea95c48857c9dfcac120d6acea43027627b28 Mon Sep 17 00:00:00 2001 From: Gerald Schaefer Date: Mon, 16 Nov 2015 14:35:48 +0100 Subject: [PATCH] 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 Reviewed-by: Sebastian Ott Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/pci_dma.h | 2 ++ arch/s390/pci/pci.c | 3 +-- arch/s390/pci/pci_dma.c | 19 ++++++++++++++----- 3 files changed, 17 insertions(+), 7 deletions(-) diff --git a/arch/s390/include/asm/pci_dma.h b/arch/s390/include/asm/pci_dma.h index 1aac41e83ea1..92df3eb8d14e 100644 --- a/arch/s390/include/asm/pci_dma.h +++ b/arch/s390/include/asm/pci_dma.h @@ -23,6 +23,8 @@ enum zpci_ioat_dtype { #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 7ef12a3ace3a..11d4f277e9f6 100644 --- a/arch/s390/pci/pci.c +++ b/arch/s390/pci/pci.c @@ -701,8 +701,7 @@ static int zpci_restore(struct device *dev) 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 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; -- 2.20.1