The sysfs layout is created by CM incorrectly presented RDMA devices with
InfiniBand link layer. Layout of such devices represents device tree of
connections. By moving CM statistics to be under relevant port of IB
device, we will fix the following issues:

 * Symlink name - It used device name instead of specific identifier.
 * Target location - It was supposed to point to PCI-ID/infiniband_cm/
   instead of PCI-ID/infiniband/
 * Target name - It created extra device file under already existing
   device folder, e.g. mlx5_0/mlx5_0
 * Crash during boot with RDMA persistent naming patches.

 sysfs: cannot create duplicate filename '/class/infiniband_cm/mlx5_0'
 CPU: 29 PID: 433 Comm: modprobe Not tainted 5.0.0-rc5+ #178
 Call Trace:
  dump_stack+0xcc/0x180
  sysfs_warn_dup.cold.3+0x17/0x2d
  sysfs_do_create_link_sd.isra.2+0xd0/0xf0
  device_add+0x7cb/0x1450
  device_create_groups_vargs+0x1ae/0x220
  device_create+0x93/0xc0
  cm_add_one+0x38f/0xf60 [ib_cm]
  add_client_context+0x167/0x210 [ib_core]
  enable_device_and_get+0x230/0x3f0 [ib_core]
  ib_register_device+0x823/0xbf0 [ib_core]
  __mlx5_ib_add+0x45/0x150 [mlx5_ib]
  mlx5_ib_add+0x1b3/0x5e0 [mlx5_ib]
  mlx5_add_device+0x130/0x3a0 [mlx5_core]
  mlx5_register_interface+0x1a9/0x270 [mlx5_core]
  do_one_initcall+0x14f/0x5de
  do_init_module+0x247/0x7c0
  load_module+0x4c2f/0x60d0
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

After this change:
[leonro@server ~]$ ls -al /sys/class/infiniband/ibp0s12f0/ports/1/
drwxr-xr-x  2 root root    0 Mar 11 11:17 cm_rx_duplicates
drwxr-xr-x  2 root root    0 Mar 11 11:17 cm_rx_msgs
drwxr-xr-x  2 root root    0 Mar 11 11:17 cm_tx_msgs
drwxr-xr-x  2 root root    0 Mar 11 11:17 cm_tx_retries

Fixes: 110cf374

 ("infiniband: make cm_device use a struct device and not a kobject.")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The check on record->event is always true because the wrong operator
is being used, used && instead of ||

Addresses-Coverity: ("Constant expression result")
Fixes: fae7a699

 ("opa_vnic: Convert vport_idr to XArray")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Combine contiguous regions of PAGE_SIZE pages into single scatter list
entry while building the scatter table for a umem. This minimizes the
number of the entries in the scatter list and reduces the DMA mapping
overhead, particularly with the IOMMU.

Set default max_seg_size in core for IB devices to 2G and do not combine
if we exceed this limit.

Also, purge npages in struct ib_umem as we now DMA map the umem SGL with
sg_nents and npage computation is not needed. Drivers should now be using
ib_umem_num_pages(), so fix the last stragglers.

Move npages tracking to ib_umem_odp as ODP drivers still need it.

Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Acked-by: Adit Ranadive <aditr@vmware.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Tested-by: Gal Pressman <galpress@amazon.com>
Tested-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Static global variables are initialized to zero by C standard,
there is no need to zero them again.

Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

On receiving a TERM from tje peer, Host moves the QP to TERMINATE state
and then moves the adapter out of RDMA mode. After issuing a TERM, peer
issues a CLOSE and at this point of time if the connectivity between peer
and host is lost for a significant amount of time, the QP remains in
TERMINATE state.

Therefore c4iw_modify_qp() needs to initiate a close on entering terminate
state.

Signed-off-by: Potnuri Bharat Teja <bharat@chelsio.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Refactor the page fault handler to be more readable and extensible, this
cleanup was triggered by the error reported below. The code structure made
it unclear to the automatic tools to identify that such a flow is not
possible in real life because "requestor != NULL" means that "qp != NULL"
too.

    drivers/infiniband/hw/mlx5/odp.c:1254 mlx5_ib_mr_wqe_pfault_handler()
    error: we previously assumed 'qp' could be null (see line 1230)

Fixes: 08100fad

 ("IB/mlx5: Add ODP SRQ support")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Moni Shoua <monis@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Based on rdma.git for-rc for dependencies.

From Dennis Dalessandro:

====================

Here are some code improvement patches and fixes for less serious bugs to
TID RDMA than we sent for RC.

====================

* HFI1 updates:
  IB/hfi1: Implement CCA for TID RDMA protocol
  IB/hfi1: Remove WARN_ON when freeing expected receive groups
  IB/hfi1: Unify the software PSN check for TID RDMA READ/WRITE
  IB/hfi1: Add a function to read next expected psn from hardware flow
  IB/hfi1: Delay the release of destination mr for TID RDMA WRITE DATA

Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Currently, FECN handling is not implemented on TID RDMA expected receive
packets and therefore CCA can't be turned on when TID RDMA is
enabled. This patch adds the CCA support to TID RDMA protocol by:

- modifying FECN RSM rule to include kernel receive contexts

- For TID_RDMA READ RESP or TID RDMA ACK packet, a CNP will be sent out if
  the FECN bit is set. For other TID RDMA packets that generate at least
  one response packet, the BECN bit will be set in the first response
  packet

- Copying expected packet data to destination buffer when FECN bit is set
  in the TID RDMA READ RESP or TID RDMA WRITE DATA packet. In this case,
  the expected packet is received as an eager packet

- Handling the TID sequence error for subsequent normal expected packets.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

When PSM user receive context is freed, the expected receive groups
allocated by the receive context will also been freed. However, if there
are still TID entries in use, the receive groups rcd->tid_full_list or
rcd->tid_used_list will not be empty, and thus triggering the WARN_ONs in
the function hfi1_free_ctxt_rcv_groups().  Even if the two lists may not
be empty, the hfi1 driver will free all TID entries and receive groups
associated with the receive context to prevent any resource leakage. Since
a clean user application exit is not controlled by the hfi1 driver, this
patch will remove the WARN_ONs in hfi1_free_ctxt_rcv_groups().

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

For expected packet receiving, the hfi1 hardware checks the KDETH PSN
automatically. However, when sequence error occurs, the hfi1 driver can
check the sequence instead until the hardware flow generation is reloaded.

TID RDMA READ and WRITE protocols implement similar software checking
mechanisms, but with different flags and different local variables to
store next expected PSN.

Unify the handling by using only one set of flag and local variable for
both TID RDMA READ and WRITE protocols.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

This patch adds a function to read next expected KDETH PSN from hardware
flow to simplify the code.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The reference of destination memory region is first obtained when TID RDMA
WRITE request is first received on the responder side. This reference is
released once all TID RDMA WRITE RESP packets are sent to the requester
side, even though not all TID RDMA WRITE DATA packets may have been
received. This early release will especially be undesired if the software
needs to access the destination memory before the last data packet is
received.

This patch delays the release of the MR until all TID RDMA DATA packets
have been received. A helper function to release the reference is also
created to simplify the code.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Kaike Wan <kaike.wan@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Conversion from IDR to XArray missed the fact that idr_alloc() returned
index as a return value, this index was saved in port variable and used as
query index later on. This caused to the following error.

 BUG: KASAN: use-after-free in cma_check_port+0x86a/0xa20 [rdma_cm]
 Read of size 8 at addr ffff888069fde998 by task ucmatose/387
 CPU: 3 PID: 387 Comm: ucmatose Not tainted 5.1.0-rc2+ #253
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-project.org 04/01/2014
 Call Trace:
  dump_stack+0x7c/0xc0
  print_address_description+0x6c/0x23c
  ? cma_check_port+0x86a/0xa20 [rdma_cm]
  kasan_report.cold.3+0x1c/0x35
  ? cma_check_port+0x86a/0xa20 [rdma_cm]
  ? cma_check_port+0x86a/0xa20 [rdma_cm]
  cma_check_port+0x86a/0xa20 [rdma_cm]
  rdma_bind_addr+0x11bc/0x1b00 [rdma_cm]
  ? find_held_lock+0x33/0x1c0
  ? cma_ndev_work_handler+0x180/0x180 [rdma_cm]
  ? wait_for_completion+0x3d0/0x3d0
  ucma_bind+0x120/0x160 [rdma_ucm]
  ? ucma_resolve_addr+0x1a0/0x1a0 [rdma_ucm]
  ucma_write+0x1f8/0x2b0 [rdma_ucm]
  ? ucma_open+0x260/0x260 [rdma_ucm]
  vfs_write+0x157/0x460
  ksys_write+0xb8/0x170
  ? __ia32_sys_read+0xb0/0xb0
  ? trace_hardirqs_off_caller+0x5b/0x160
  ? do_syscall_64+0x18/0x3c0
  do_syscall_64+0x95/0x3c0
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

  Allocated by task 381:
   __kasan_kmalloc.constprop.5+0xc1/0xd0
   cma_alloc_port+0x4d/0x160 [rdma_cm]
   rdma_bind_addr+0x14e7/0x1b00 [rdma_cm]
   ucma_bind+0x120/0x160 [rdma_ucm]
   ucma_write+0x1f8/0x2b0 [rdma_ucm]
   vfs_write+0x157/0x460
   ksys_write+0xb8/0x170
   do_syscall_64+0x95/0x3c0
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

  Freed by task 381:
   __kasan_slab_free+0x12e/0x180
   kfree+0xed/0x290
   rdma_destroy_id+0x6b6/0x9e0 [rdma_cm]
   ucma_close+0x110/0x300 [rdma_ucm]
   __fput+0x25a/0x740
   task_work_run+0x10e/0x190
   do_exit+0x85e/0x29e0
   do_group_exit+0xf0/0x2e0
   get_signal+0x2e0/0x17e0
   do_signal+0x94/0x1570
   exit_to_usermode_loop+0xfa/0x130
   do_syscall_64+0x327/0x3c0
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

Reported-by:  <syzbot+2e3e485d5697ea610460@syzkaller.appspotmail.com>
Reported-by: Ran Rozenstein <ranro@mellanox.com>
Fixes: 63826753

 ("cma: Convert portspace IDRs to XArray")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

port_pd is treated as le32 in declaration and read, fix assignment to be
in le32 too. This change fixes the following compilation warnings.

drivers/infiniband/hw/hns/hns_roce_ah.c:67:24: warning: incorrect type
in assignment (different base types)
drivers/infiniband/hw/hns/hns_roce_ah.c:67:24: expected restricted __le32 [usertype] port_pd
drivers/infiniband/hw/hns/hns_roce_ah.c:67:24: got restricted __be32 [usertype]

Fixes: 9a443537

 ("IB/hns: Add driver files for hns RoCE driver")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Gal Pressman <galpress@amazon.com>
Reviewed-by: Lijun Ou <ouliun@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Now when ib_udata is passed to all the driver's object create/destroy APIs
the ib_udata will carry the ib_ucontext for every user command. There is
no need to also pass the ib_ucontext via the functions prototypes.

Make ib_udata the only argument psssed.

Signed-off-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Now that we have the udata passed to all the ib_xxx object destroy APIs
and the additional macro 'rdma_udata_to_drv_context' to get the
ib_ucontext from ib_udata stored in uverbs_attr_bundle, we can finally
start to remove the dependency of the drivers in the
ib_xxx->uobject->context.

Signed-off-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The uverbs_attr_bundle with the ucontext is sent down to the drivers ib_x
destroy path as ib_udata. The next patch will use the ib_udata to free the
drivers destroy path from the dependency in 'uobject->context' as we
already did for the create path.

Signed-off-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Pass uverbs_attr_bundle down the uobject destroy path. The next patch will
use this to eliminate the dependecy of the drivers in ib_x->uobject
pointers.

Signed-off-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

the Attempt to use the below commit to initialize the ucontext for the
uobject destroy path has shown that the below commit is incomplete.

Parts were reverted and the ucontext set up in the uverbs_attr_bundle was
moved to rdma_lookup_get_uobject which is called from the uobj_get_XXX
macros and rdma_alloc_begin_uobject which is called when uobject is
created.

Fixes: 3d9dfd06

 ("IB/uverbs: Add ib_ucontext to uverbs_attr_bundle sent from ioctl and cmd flows")
Signed-off-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Also remove qib_devs_list.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Also remove hfi1_devs_list.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

There is no need to perform extra comparison after boolean AND.

Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Delete structure which is not connected due to removal in commit
cited in Fixes line.

Fixes: a78e8723

 ("RDMA/cma: Remove CM_ID statistics provided by rdma-cm module")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Also fully initialise the qp before storing it in the XArray.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Change the locking to not disable interrupts as the lookup in interrupt
context will not see a freed CQ, thanks to the synchronize_irq() call
before freeing the CQ.

Signed-off-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Add netlink command that enables/disables sharing rdma device among
multiple net namespaces.

Using rdma tool,
$rdma sys set netns shared (default mode)

When rdma subsystem netns mode is set to shared mode, rdma devices
will be accessible in all net namespaces.

Using rdma tool,
$rdma sys set netns exclusive

When rdma subsystem netns mode is set to exclusive mode, devices
will be accessible in only one net namespace at any given
point of time.

If there are any net namespaces other than default init_net exists,
while executing this command, it will fail and mode cannot be changed.

To change this mode, netlink command is used instead of sysctl, because
netlink command allows to auto load a module.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Add an interface via netlink command to query whether rdma devices are
shared among multiple net namespaces or not. When using RDMAtool, it can
be queried as,

$rdma system show netns
netns shared

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Extend ib_device_get_by_index() API to check device access for
net namespace for serving netlink commands.

Also enforce net ns check on dumpit commands which iterate over all
registered rdma devices and which don't call ib_device_get_by_index().

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Introduce an API rdma_dev_access_netns() to check whether a rdma device
can be accessed from the specified net namespace or not.
Use rdma_dev_access_netns() while opening character uverbs, umad network
device and also check while rdma cm_id binds to rdma device.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Add module parameter to change a sharing mode of ib_core early in the
boot process. This parameter helps to those systems where modern up
to date rdma tool (iproute2) package may not be available during
kernel upgrade cycle.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Now that sysfs compatibility layer for non init_net exists, add core port
attributes such as pkey and gid table to non init_net ns.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

Implement compatibility layer sysfs entries of ib_core so that non
init_net net namespaces can also discover rdma devices.

Each non init_net net namespace has ib_core_device created in it.
Such ib_core_device sysfs tree resembles rdma devices found in
init_net namespace.

This allows discovering rdma devices in multiple non init_net net
namespaces via sysfs entries and helpful to rdma-core userspace.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

This is a preparation patch to provide isolation of rdma device in a
network namespace.

As first step, make rdma device visible only in init net namespace.
Subsequent patch will enable rdma device visibility back in multiple net
namespaces using compat ib_core_device device/sysfs tree.

Given that the IB subsystem depends on net stack, it needs to be
initialized after netdev and since it support devices, it needs to be
initialized before the device subsystem; therefore, change initcall
sequence to fs_initcall, so that when ib_core is compiled in the kernel
image, the right init sequence is followed.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

In order to support sysfs entries in multiple net namespaces for a rdma
device, introduce a ib_core_device whose scope is limited to hold core
device and per port sysfs related entries.

This is preparation patch so that multiple ib_core_devices in each net
namespace can be created in subsequent patch who all can share ib_device.

(a) Move sysfs specific fields to ib_core_device.
(b) Make sysfs and device life cycle related routines to work on
    ib_core_device.
(c) Introduce and use rdma_init_coredev() helper to initialize
    coredev fields.

Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The buffer that holds the page DMA addresses is sized off umem->nmap.
This can potentially cause out of bound accesses on the PBL array when
iterating the umem DMA-mapped SGL. This is because if umem pages are
combined, umem->nmap can be much lower than the number of system pages
in umem.

Use ib_umem_num_pages() to size this buffer.

Cc: Dennis Dalessandro <dennis.dalessandro@intel.com>
Cc: Mike Marciniszyn <mike.marciniszyn@intel.com>
Cc: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

The buffer that holds the page DMA addresses is sized off umem->nmap.
This can potentially cause out of bound accesses on the PBL array when
iterating the umem DMA-mapped SGL. This is because if umem pages are
combined, umem->nmap can be much lower than the number of system pages
in umem.

Use ib_umem_num_pages() to size this buffer.

Cc: Moni Shoua <monis@mellanox.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>