brain-hackers_pepepper-mirror
/
linux-brain
mirror of https://github.com/brain-hackers/linux-brain.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

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>
This commit is contained in:
Gerald Schaefer 2015-11-16 14:35:48 +01:00 committed by Martin Schwidefsky
parent 406123517b
commit 69eea95c48
3 changed files with 17 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/s390/include/asm/pci_dma.h
View File

@ -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)

3
arch/s390/pci/pci.c
View File

@ -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:

19
arch/s390/pci/pci_dma.c
View File

@ -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;