The mempool is for guaranteed memory allocation during
extreme VM load (see the header of mempool.c of the kernel).
But rtrs-srv allocates pages only when creating new session.
There is no need to use the mempool.

With the removal of mempool, rtrs-server no longer need to reserve
huge mount of memory, this will avoid error like this:
https://lore.kernel.org/lkml/20220620020727.GA3669@xsang-OptiPlex-9020/

Link: https://lore.kernel.org/r/20220712103113.617754-6-haris.iqbal@ionos.com
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Gioh Kim <gi-oh.kim@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

removes list_next_or_null_rr_rcu macro to fix below warnings.
That macro is used only twice.
CHECK:MACRO_ARG_REUSE: Macro argument reuse 'head' - possible side-effects?
CHECK:MACRO_ARG_REUSE: Macro argument reuse 'ptr' - possible side-effects?
CHECK:MACRO_ARG_REUSE: Macro argument reuse 'memb' - possible side-effects?

Replaces that macro with an inline function.

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Cc: jinpu.wang@ionos.com
Link: https://lore.kernel.org/r/20220712103113.617754-5-haris.iqbal@ionos.com
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Convert server stat counters from atomic to per-cpu variables.

Link: https://lore.kernel.org/r/20220712103113.617754-4-haris.iqbal@ionos.com
Signed-off-by: Santosh Kumar Pradhan <santosh.pradhan@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Use this_cpu_x() for increasing/adding a percpu counter through a
percpu pointer without the need to disable/enable preemption.

Link: https://lore.kernel.org/r/20220712103113.617754-3-haris.iqbal@ionos.com
Suggested-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Santosh Kumar Pradhan <santosh.pradhan@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Acked-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Reviewed-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

stringify works with define, not enum.

Fixes: 91fddedd439c ("RDMA/rtrs: private headers with rtrs protocol structs and helpers")
Cc: jinpu.wang@ionos.com
Link: https://lore.kernel.org/r/20220712103113.617754-2-haris.iqbal@ionos.com
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Reviewed-by: Aleksei Marov <aleksei.marov@ionos.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Use bitmap_empty() instead of hand-writing them.

Link: https://lore.kernel.org/r/b71ccfaf4a47dee8e1ad373604c861479d499b6b.1657298747.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Use bitmap_zalloc()/bitmap_free() instead of hand-writing them.

It is less verbose and it improves the semantic.

Link: https://lore.kernel.org/r/ca9c5c8301d76d60de34640568b3db0d4401d050.1657298747.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Add the description of @pathname and remove @sessname in rtrs_clt_open()
kernel-doc comment to remove warnings found by running scripts/kernel-doc,
which is caused by using 'make W=1'.

drivers/infiniband/ulp/rtrs/rtrs-clt.c:2809: warning: Function parameter or member 'pathname' not described in 'rtrs_clt_open'
drivers/infiniband/ulp/rtrs/rtrs-clt.c:2809: warning: Excess function parameter 'sessname' description in 'rtrs_clt_open'

Link: https://lore.kernel.org/r/20220526130945.98601-1-yang.lee@linux.alibaba.com
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

Pull rdma updates from Jason Gunthorpe:

 - Minor bug fixes in mlx5, mthca, pvrdma, rtrs, mlx4, hfi1, hns

 - Minor cleanups: coding style, useless includes and documentation

 - Reorganize how multicast processing works in rxe

 - Replace a red/black tree with xarray in rxe which improves performance

 - DSCP support and HW address handle re-use in irdma

 - Simplify the mailbox command handling in hns

 - Simplify iser now that FMR is eliminated

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (93 commits)
  RDMA/nldev: Prevent underflow in nldev_stat_set_counter_dynamic_doit()
  IB/iser: Fix error flow in case of registration failure
  IB/iser: Generalize map/unmap dma tasks
  IB/iser: Use iser_fr_desc as registration context
  IB/iser: Remove iser_reg_data_sg helper function
  RDMA/rxe: Use standard names for ref counting
  RDMA/rxe: Replace red-black trees by xarrays
  RDMA/rxe: Shorten pool names in rxe_pool.c
  RDMA/rxe: Move max_elem into rxe_type_info
  RDMA/rxe: Replace obj by elem in declaration
  RDMA/rxe: Delete _locked() APIs for pool objects
  RDMA/rxe: Reverse the sense of RXE_POOL_NO_ALLOC
  RDMA/rxe: Replace mr by rkey in responder resources
  RDMA/rxe: Fix ref error in rxe_av.c
  RDMA/hns: Use the reserved loopback QPs to free MR before destroying MPT
  RDMA/irdma: Add support for address handle re-use
  RDMA/qib: Fix typos in comments
  RDMA/mlx5: Fix memory leak in error flow for subscribe event routine
  Revert "RDMA/core: Fix ib_qp_usecnt_dec() called when error"
  RDMA/rxe: Remove useless argument for update_state()
  ...

Error path of rtrs_clt_open() calls free_clt(), where free_permit is
called.  This is wrong since error path of rtrs_clt_open() does not need
to call free_permit().

Also, moving free_permits() call to rtrs_clt_close(), makes it more
aligned with the call to alloc_permit() in rtrs_clt_open().

Fixes: 6a98d71daea1 ("RDMA/rtrs: client: main functionality")
Link: https://lore.kernel.org/r/20220217030929.323849-2-haris.iqbal@ionos.com
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Reviewed-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>