Method to test direct memory access (DMA) address capabilities at high address values
AssigneeTeledyne LeCroy, Inc.
InventorsAaron Masters, Kevin Lemay, Chuck Tuffli
Life of this patent
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Abstract
A method for detecting a Direct Memory Access (DMA) address capability at high address values when testing PCIe devices is disclosed. The method includes enabling an input/output (I/O) memory management unit (IOMMU); remapping physical addresses to virtual addresses at a high end of an address range; adding a peripheral component interconnect express (PCIe) device; and mapping physical memory addresses to high value memory addresses.
Claims19
A method for detecting a Direct Memory Access (DMA) address capability at high address values when testing PCIe devices, the method comprising:
- enabling an input/output (I/O) memory management unit (IOMMU);
- adding a peripheral component interconnect express (PCIe) device;
- creating by the IOMMU a specified virtual memory address space to the device;
- setting the specified virtual address space to high end of address space beyond a memory address range of physical memory;
- mapping physical memory addresses to high value memory addresses, wherein a high value memory address is defined as a memory address in an upper limit of an addressing range of a central processing unit (CPU);
- and
- checking direct memory access by the device against the specified virtual memory address space.
A non-transitory computer readable medium storing a kernel configuration module which, when executed by a processor of a computing device, detects a Direct Memory Access (DMA) address capability at high address values when testing PCIe devices, said a kernel configuration module comprising sets of instructions for:
- enabling an input/output (I/O) memory management unit (IOMMU);
- adding a peripheral component interconnect express (PCIe) device;
- creating by the IOMMU a specified virtual memory address space to the device;
- setting the specified virtual address space to high end of address space beyond a memory address range of physical memory;
- mapping physical memory addresses to high value memory addresses, wherein a high value memory address is defined as a memory address in an upper limit of an addressing range of a central processing unit (CPU);
- and
- checking direct memory access by the device against the specified virtual memory address space.
A method for detecting a Direct Memory Access (DMA) address capability at high address values when testing PCIe devices, the method comprising:
- enabling an input/output (I/O) memory management unit (IOMMU);
- adding a peripheral component interconnect express (PCIe) device;
- assigning by the IOMMU a virtual memory address space to the device;
- creating by the IOMMU a specified virtual memory address space to the device;
- setting the specified virtual address space to high end of address space beyond a memory address range of physical memory;
- mapping physical memory addresses to high value memory addresses, wherein a high value memory address is defined as a memory address in an upper limit of an addressing range of a central processing unit (CPU);
- and
- verifying direct memory access addressing capability of the device at the high end of the address range.
Dependencies are inferred from the claim text.