14dea2d1aSSukadev Bhattiprolu* IBM Powerpc Virtual Accelerator Switchboard (VAS) 24dea2d1aSSukadev Bhattiprolu 34dea2d1aSSukadev BhattiproluVAS is a hardware mechanism that allows kernel subsystems and user processes 44dea2d1aSSukadev Bhattiproluto directly submit compression and other requests to Nest accelerators (NX) 54dea2d1aSSukadev Bhattiproluor other coprocessors functions. 64dea2d1aSSukadev Bhattiprolu 74dea2d1aSSukadev BhattiproluRequired properties: 84dea2d1aSSukadev Bhattiprolu- compatible : should be "ibm,vas". 94dea2d1aSSukadev Bhattiprolu- ibm,vas-id : A unique identifier for each instance of VAS in the system 104dea2d1aSSukadev Bhattiprolu- reg : Should contain 4 pairs of 64-bit fields specifying the Hypervisor 114dea2d1aSSukadev Bhattiprolu window context start and length, OS/User window context start and length, 124dea2d1aSSukadev Bhattiprolu "Paste address" start and length, "Paste window id" start bit and number 134dea2d1aSSukadev Bhattiprolu of bits) 144dea2d1aSSukadev Bhattiprolu 154dea2d1aSSukadev BhattiproluExample: 164dea2d1aSSukadev Bhattiprolu 174dea2d1aSSukadev Bhattiprolu vas@6019100000000 { 184dea2d1aSSukadev Bhattiprolu compatible = "ibm,vas", "ibm,power9-vas"; 194dea2d1aSSukadev Bhattiprolu reg = <0x6019100000000 0x2000000 0x6019000000000 0x100000000 0x8000000000000 0x100000000 0x20 0x10>; 204dea2d1aSSukadev Bhattiprolu name = "vas"; 214dea2d1aSSukadev Bhattiprolu ibm,vas-id = <0x1>; 224dea2d1aSSukadev Bhattiprolu }; 23