Visible to Intel only — GUID: chx1672948434222
Ixiasoft
Visible to Intel only — GUID: chx1672948434222
Ixiasoft
5.1. System Register Map
Refer to the respective IP/subsystem documentation for internal address offsets. At the system level, BAR2 of each PF drive the downstream CSR space through the MCDMA PIO interface. Registers inside MCDMA are targeted to BAR0 of each PF for Queue control (D2H and H2D directions) and MSI-X table updates. General CSR (GCSR) of MCDMA is only maintained by PF0-BAR0.
The PIO address is arranged as {vf_active,clog2(PF_NUM),clog2(VF_NUM),PIO BAR2 Address} where vf_active, clog2(PF_NUM) and clog2(VF_NUM) are declared as 1-bit each since we support only 2 PFs and no VFs. Each PF’s BAR2 can be enabled for 32MB i.e. 26-bit interface and the upper address bits differentiate the addressing between 2 PFs. The PIO interface is accessible irrespective of configuring the datapath queues. Since this design does not support any VFs, vf address bits are removed from AVMM address using BAR interpreter logic which reduces the needed address range for design.