• Ian Munsie's avatar
    cxl: Driver code for powernv PCIe based cards for userspace access · f204e0b8
    Ian Munsie authored
    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: default avatarIan Munsie <imunsie@au1.ibm.com>
    Signed-off-by: default avatarMichael Neuling <mikey@neuling.org>
    Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    f204e0b8
sysfs.c 8.89 KB