linux/linux-stable.git - Linux kernel stable tree

Age	Commit message (Collapse)	Author
2014-11-18	cxl: Return error to PSL if IRQ demultiplexing fails & print clearer warning	Ian Munsie
	If an AFU has a hardware bug that causes it to acknowledge a context terminate or remove while that context has outstanding transactions, it is possible for the kernel to receive an interrupt for that context after we have removed it from the context list. The kernel will not be able to demultiplex the interrupt (or worse - if we have already reallocated the process handle we could mis-attribute it to the new context), and printed a big scary warning. It did not acknowledge the interrupt, which would effectively halt further translation fault processing on the PSL. This patch makes the warning clearer about the likely cause of the issue (i.e. hardware bug) to make it obvious to future AFU designers of what needs to be fixed. It also prints out the process handle which can then be matched up with hardware and software traces for debugging. It also acknowledges the interrupt to the PSL with either an address error or acknowledge, so that the PSL can continue with other translations. Signed-off-by: Ian Munsie <imunsie@au1.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-10-08	cxl: Driver code for powernv PCIe based cards for userspace access	Ian Munsie
	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>