litmus-rt.git - The LITMUS^RT kernel.

	Commit message (Collapse)	Author	Age
*	cxl: Disable secondary hash in segment table	Ian Munsie	2014-10-28
\| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \|	This patch simplifies the process of finding a free segment table entry by disabling the secondary hash. This reduces the number of possible entries in the segment table for a given address from 16 to 8. Due to the large segment sizes we use it is extremely unlikely that the secondary hash would ever have been used in practice, so this should not have any negative impacts and may even improve performance due to the reduced number of comparisons that software & hardware need to perform. This patch clears the SC bit in the hardware's state register (CXL_PSL_SR_An) to disable the secondary hash in the hardware since we can no longer fill out entries using it. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
*	cxl: Driver code for powernv PCIe based cards for userspace access	Ian Munsie	2014-10-08
	This is the core of the cxl driver. It adds support for using cxl cards in the powernv environment only (ie POWER8 bare metal). It allows access to cxl accelerators by userspace using the /dev/cxl/afuM.N char devices. The kernel driver has no knowledge of the function implemented by the accelerator. It provides services to userspace via the /dev/cxl/afuM.N devices. When a program opens this device and runs the start work IOCTL, the accelerator will have coherent access to that processes memory using the same virtual addresses. That process may mmap the device to access any MMIO space the accelerator provides. Also, reads on the device will allow interrupts to be received. These services are further documented in a later patch in Documentation/powerpc/cxl.txt. Documentation of the cxl hardware architecture and userspace API is provided in subsequent patches. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>