[openib-general] moving IBM eHCA Device Driver to openib.org

[Roland Dreier]

Here are a few quick notes based on spending a little while skimming
through some of the ehca source code:

ehca_asm.h:
    this stuff should be in include/asm and mostly already is:
        asm_sync_mem is just the standard mb() from <asm/system.h>.
        mftb() is get_tb() from <asm/time.h>
        so you just need to add prefetch_zero to include/asm-ppc64

ehca_classes.c:
    why have ehca_module_new?  it seems to be used to allocate a
    single instance of a struct that should just be module-global variables.

ehca_classes_pSeries.h:
    Why have EHCA_MEMPAGESIZE and EHCA_MEMPAGESIZE_MASK?  Can they be
    different from PAGE_SIZE and PAGE_MASK?

    Get rid of typedefs of struct hcp_eq_handle -- just use structs
    directly in code.

    Can struct hcp_modify_qp_control_block declaration be made readable?

ehca_common.h:
    why have typedef of ehca_redcode_t?  Just use long directly.

    ntohd() seems to duplicate be64_to_cpu() except without proper
    __be64 annotation -- why is it needed?

ehca_irq.c:
    in ehca_comp_event_callback(), what protects against the CQ being
    destroyed out from under you?

ehca_kernel.h:
    ehca_sleep() and ehca_msleep() duplicate msleep_interruptible().

    why is assert() needed instead of just using BUG_ON()

    why have MIN() and MAX() instad of just using min()/max()?

    ehca_kv_to_g() looks rather horrible -- why are you working with
    kernel virtual addresses at all?

    ehca_kr_to_g() looks like it is a substitute for dma_map_single()
    Why not use the correct DMA API instead?

ehca_main.c:
    ehca_module_exit() -- I don't see where ehca_wq is destroyed.

    ehca_module_exit() -- what prevents ehca_poll_eq() from running
        after the module text is gone?  You don't wait for the kthread
        to actually stop, and it might be in the middle of the sleep.