> Subject: Re: [RDMA RFC v6 00/16] Intel RDMA Driver Updates 2020-05-19 > > On Wed, May 20, 2020 at 12:03:59AM -0700, Jeff Kirsher wrote: > > This patch set adds a unified Intel Ethernet Protocol Driver for RDMA > > that supports a new network device E810 (iWARP and RoCEv2 capable) and > > the existing X722 iWARP device. The driver architecture provides the > > extensibility for future generations of Intel HW supporting RDMA. > > > > This driver replaces the legacy X722 driver i40iw and extends the ABI > > already defined for i40iw. It is backward compatible with legacy X722 > > rdma-core provider (libi40iw). > > > > This series was built against the rdma for-next branch. This series > > is dependant upon the v4 100GbE Intel Wired LAN Driver Updates > > 2020-05-19 > > 12 patch series, which adds virtual_bus interface and ice/i40e LAN > > driver changes. > > > > v5-->v6: > > *Convert irdma destroy QP to a synchronous API *Drop HMC obj macros > > for use counts like IRDMA_INC_SD_REFCNT et al. > > *cleanup unneccesary 'mem' variable in irdma_create_qp *cleanup unused > > headers such as linux/moduleparam.h et. al *set kernel_ver in > > irdma_ualloc_resp struct to current ABI ver. Placeholder to support > > user-space compatbility checks in future *GENMASK/FIELD_PREP scheme to > > set WQE descriptor fields considered for irdma driver but decision to > > drop. The FIELD_PREP macro cannot be used on the device bitfield mask > > array maintained for common WQE descriptors and initialized based on > > HW generation. The macro expects compile time constants only. > > The request was to use GENMASK for the #define constants. If you move to a > code environment then the spot the constant appears in the C code should be > FIELD_PREP'd into the something dynamic code can use. > Maybe I am missing something here, but from what I understood, the vantage point of using GENMASK for the masks was so that we could get rid of open coding the shift constants and use the FIELD_PREP macro to place the value in the field of a descriptor. This should work for the static masks. So something like -- -#define IRDMA_UDA_QPSQ_INLINEDATALEN_S 48 -#define IRDMA_UDA_QPSQ_INLINEDATALEN_M \ - ((u64)0xff << IRDMA_UDA_QPSQ_INLINEDATALEN_S) +#define IRDMA_UDA_QPSQ_INLINEDATALEN_M GENMASK_ULL(55, 48) -#define LS_64(val, field) (((u64)(val) << field ## _S) & (field ## _M)) +#define LS_64(val, field) (FIELD_PREP(val,(field ## _M))) However we have device's dynamically computed bitfield mask array and shifts for some WQE descriptor fields -- see icrdma_init_hw.c https://lore.kernel.org/linux-rdma/20200520070415.3392210-3-jeffrey.t.kirsher@xxxxxxxxx/#Z30drivers:infiniband:hw:irdma:icrdma_hw.c we still need to use the custom macro FLD_LS_64 without FIELD_PREP in this case as FIELD_PREP expects compile time constants. +#define FLD_LS_64(dev, val, field) \ + (((u64)(val) << (dev)->hw_shifts[field ## _S]) & (dev)->hw_masks[field +## _M]) And the shifts are still required for these fields which causes a bit of inconsistency
