remove debug messages for tx dma testing (will be put again after tx
revision)
add wmb before posting write[q/l] for tx
add clflush right after wmb in lbuf_xmit

- originally, pcie read request invalidates its address range carrying
No Snoop bit cleared in its TLP header. But, I found that not invalidating
packets are rarely happending, thereby breaking consistency between
SW and HW. We haven't found the cause by now, but clflush right before
write[q/l] solves the issue as a explicit cache flush from sw-side.
fix error handling bug when phy chip initialization fails
change synchronization for pending_gc_head in finer-grained

- change clean_complete return code in tx clean irq handler
  - before: return 0 if no gc address
  - after: return emptiness of pending_gc_head even if no gc address
  -> napi can keep poll if pending tx buffer exists

- add rmb before reading tx gc address from HW
add cpu info in tx debugging logs
remove tx_lock sync only for queue_tx_packet

- significanly reduce tx_lock contention when tx thread is not pinned.
  (tx thread queues a packet on cpu0 -> lbuf worker scheduled on cpu0 ->
  tx thread queues a next packet on cpu1 (since cpu0 is occupied by lbuf
  worker thread) -> contention between tx thread and lbuf worker thread
  for tx_lock. But, tx thread doesn' need tx_lock sync when just queuing
  a packet without touching tx descriptors and pointers.
fix a bug for unlikely memory leak of desc
remove clflush out for now with performance debugging

- misc: comment out 'qpkt' deubgging message for performance
pull memory alloc function (get_lbuf) out of tx_queue critical section
remove GFP_TRANSHUGE in alloc_lbuf

- GFP_TRANSHUGE adds __GFP_WAIT which allow sleeping, but alloc_lbuf can
  be called when in_atomic() is true. For example, nf10_lbuf_start_xmit,
  which calls alloc_lbuf inside, is invoked with 3-5 locks held
  (including rcu read locks, which disable preemption).
  Now, it is changed to GFP_ATOMIC and later it will be optimized using
  huge page.
add back clflush
replace wmb->clflush with safe flush (mb->clflush->mb)
Merge branch 'tx_revision' of https://github.com/NetFPGA-NewNIC/linux-driver into tx_revision
Merge branch 'master' into tx_revision