1*c66ec88fSEmmanuel Vadot* IBM Powerpc Virtual Accelerator Switchboard (VAS) 2*c66ec88fSEmmanuel Vadot 3*c66ec88fSEmmanuel VadotVAS is a hardware mechanism that allows kernel subsystems and user processes 4*c66ec88fSEmmanuel Vadotto directly submit compression and other requests to Nest accelerators (NX) 5*c66ec88fSEmmanuel Vadotor other coprocessors functions. 6*c66ec88fSEmmanuel Vadot 7*c66ec88fSEmmanuel VadotRequired properties: 8*c66ec88fSEmmanuel Vadot- compatible : should be "ibm,vas". 9*c66ec88fSEmmanuel Vadot- ibm,vas-id : A unique identifier for each instance of VAS in the system 10*c66ec88fSEmmanuel Vadot- reg : Should contain 4 pairs of 64-bit fields specifying the Hypervisor 11*c66ec88fSEmmanuel Vadot window context start and length, OS/User window context start and length, 12*c66ec88fSEmmanuel Vadot "Paste address" start and length, "Paste window id" start bit and number 13*c66ec88fSEmmanuel Vadot of bits) 14*c66ec88fSEmmanuel Vadot 15*c66ec88fSEmmanuel VadotExample: 16*c66ec88fSEmmanuel Vadot 17*c66ec88fSEmmanuel Vadot vas@6019100000000 { 18*c66ec88fSEmmanuel Vadot compatible = "ibm,vas", "ibm,power9-vas"; 19*c66ec88fSEmmanuel Vadot reg = <0x6019100000000 0x2000000 0x6019000000000 0x100000000 0x8000000000000 0x100000000 0x20 0x10>; 20*c66ec88fSEmmanuel Vadot name = "vas"; 21*c66ec88fSEmmanuel Vadot ibm,vas-id = <0x1>; 22*c66ec88fSEmmanuel Vadot }; 23