1*4882a593Smuzhiyun* IBM Powerpc Virtual Accelerator Switchboard (VAS) 2*4882a593Smuzhiyun 3*4882a593SmuzhiyunVAS is a hardware mechanism that allows kernel subsystems and user processes 4*4882a593Smuzhiyunto directly submit compression and other requests to Nest accelerators (NX) 5*4882a593Smuzhiyunor other coprocessors functions. 6*4882a593Smuzhiyun 7*4882a593SmuzhiyunRequired properties: 8*4882a593Smuzhiyun- compatible : should be "ibm,vas". 9*4882a593Smuzhiyun- ibm,vas-id : A unique identifier for each instance of VAS in the system 10*4882a593Smuzhiyun- reg : Should contain 4 pairs of 64-bit fields specifying the Hypervisor 11*4882a593Smuzhiyun window context start and length, OS/User window context start and length, 12*4882a593Smuzhiyun "Paste address" start and length, "Paste window id" start bit and number 13*4882a593Smuzhiyun of bits) 14*4882a593Smuzhiyun 15*4882a593SmuzhiyunExample: 16*4882a593Smuzhiyun 17*4882a593Smuzhiyun vas@6019100000000 { 18*4882a593Smuzhiyun compatible = "ibm,vas", "ibm,power9-vas"; 19*4882a593Smuzhiyun reg = <0x6019100000000 0x2000000 0x6019000000000 0x100000000 0x8000000000000 0x100000000 0x20 0x10>; 20*4882a593Smuzhiyun name = "vas"; 21*4882a593Smuzhiyun ibm,vas-id = <0x1>; 22*4882a593Smuzhiyun }; 23