RDMA/mlx5: Lower setting the umem's PAS for SRQ

Some of the SRQ types are created using a WQ, and the WQ requires a
different parameter set to mlx5_umem_find_best_quantized_pgoff() as it has
a 5 bit page_offset.

Add the umem to the mlx5_srq_attr and defer computing the PAS data until
the code has figured out what kind of mailbox to use. Compute the PAS
directly from the umem for each of the four unique mailbox types.

This also avoids allocating memory to store the user PAS, instead it is
written directly to the mailbox as in most other cases.

Fixes: 01949d0109ee ("net/mlx5_core: Enable XRCs and SRQs when using ISSI > 0")
Link: https://lore.kernel.org/r/20201115114311.136250-8-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA: Restore ability to fail on SRQ destroy

In similar way to other IB objects, restore the ability to return error on
SRQ destroy. Strictly speaking, this change is not necessary, and provided
here to ensure a symmetrical interface like other destroy functions.

Fixes: 68e326dea1db ("RDMA: Handle SRQ allocations by IB/core")
Link: https://lore.kernel.org/r/20200907120921.476363-5-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/mlx5: Issue FW command to destroy SRQ on reentry

The HW release can fail and leave the system in limbo state, where SRQ is
removed from the table, but can't be destroyed later. In every reentry,
the initial xa_erase_irq() check will fail.

Rewrite the erase logic to keep index, but don't store the entry
itself. By doing it, we can safely reinsert entry back in the case of
destroy failure.

Link: https://lore.kernel.org/r/20200907120921.476363-4-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/mlx5: Use xa_lock_irq when access to SRQ table

SRQ table is accessed both from interrupt and process context,
therefore we must use xa_lock_irq.

inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
kworker/u17:9/8573 takes:
ffff8883e3503d30 (&xa->xa_lock#13){?...}-{2:2}, at: mlx5_cmd_get_srq+0x18/0x70 [mlx5_ib]
{IN-HARDIRQ-W} state was registered at:
lock_acquire+0xb9/0x3a0
_raw_spin_lock+0x25/0x30
srq_event_notifier+0x2b/0xc0 [mlx5_ib]
notifier_call_chain+0x45/0x70
__atomic_notifier_call_chain+0x69/0x100
forward_event+0x36/0xc0 [mlx5_core]
notifier_call_chain+0x45/0x70
__atomic_notifier_call_chain+0x69/0x100
mlx5_eq_async_int+0xc5/0x160 [mlx5_core]
notifier_call_chain+0x45/0x70
__atomic_notifier_call_chain+0x69/0x100
mlx5_irq_int_handler+0x19/0x30 [mlx5_core]
__handle_irq_event_percpu+0x43/0x2a0
handle_irq_event_percpu+0x30/0x70
handle_irq_event+0x34/0x60
handle_edge_irq+0x7c/0x1b0
do_IRQ+0x60/0x110
ret_from_intr+0x0/0x2a
default_idle+0x34/0x160
do_idle+0x1ec/0x220
cpu_startup_entry+0x19/0x20
start_secondary+0x153/0x1a0
secondary_startup_64+0xa4/0xb0
irq event stamp: 20907
hardirqs last enabled at (20907): _raw_spin_unlock_irq+0x24/0x30
hardirqs last disabled at (20906): _raw_spin_lock_irq+0xf/0x40
softirqs last enabled at (20746): __do_softirq+0x2c9/0x436
softirqs last disabled at (20681): irq_exit+0xb3/0xc0

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(&xa->xa_lock#13);
<Interrupt>
lock(&xa->xa_lock#13);

*** DEADLOCK ***

2 locks held by kworker/u17:9/8573:
#0: ffff888295218d38 ((wq_completion)mlx5_ib_page_fault){+.+.}-{0:0}, at: process_one_work+0x1f1/0x5f0
#1: ffff888401647e78 ((work_completion)(&pfault->work)){+.+.}-{0:0}, at: process_one_work+0x1f1/0x5f0

stack backtrace:
CPU: 0 PID: 8573 Comm: kworker/u17:9 Tainted: GO 5.7.0_for_upstream_min_debug_2020_06_14_11_31_46_41 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
Workqueue: mlx5_ib_page_fault mlx5_ib_eqe_pf_action [mlx5_ib]
Call Trace:
dump_stack+0x71/0x9b
mark_lock+0x4f2/0x590
? print_shortest_lock_dependencies+0x200/0x200
__lock_acquire+0xa00/0x1eb0
lock_acquire+0xb9/0x3a0
? mlx5_cmd_get_srq+0x18/0x70 [mlx5_ib]
_raw_spin_lock+0x25/0x30
? mlx5_cmd_get_srq+0x18/0x70 [mlx5_ib]
mlx5_cmd_get_srq+0x18/0x70 [mlx5_ib]
mlx5_ib_eqe_pf_action+0x257/0xa30 [mlx5_ib]
? process_one_work+0x209/0x5f0
process_one_work+0x27b/0x5f0
? __schedule+0x280/0x7e0
worker_thread+0x2d/0x3c0
? process_one_work+0x5f0/0x5f0
kthread+0x111/0x130
? kthread_park+0x90/0x90
ret_from_fork+0x24/0x30

Fixes: e126ba97dba9 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Link: https://lore.kernel.org/r/20200712102641.15210-1-leon@kernel.org
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/mlx5: Fix query_srq_cmd() function

The output buffer used in mlx5_cmd_exec_inout() was wrongly changed from
pre-allocated srq_out pointer to an input "out" point. That leads to
unpredictable results in the get_srqc() call later.

Fixes: 31578defe4eb ("RDMA/mlx5: Update mlx5_ib to use new cmd interface")
Link: https://lore.kernel.org/r/20200513100809.246315-1-leon@kernel.org
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/mlx5: Update mlx5_ib to use new cmd interface

Reuse newly introduced mlx5_cmd_exec_in() and mlx5_cmd_exec_inout() to
reduce code duplication in mlx5_ib module.

Link: https://lore.kernel.org/r/20200506065513.4668-2-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

net/mlx5: Move QP logic to mlx5_ib

The mlx5_core doesn't need any functionality coded in qp.c, so move
that file to drivers/infiniband/ be under mlx5_ib responsibility.

Reviewed-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

net/mlx5: Delete not-used cmd header

The structures defined in the cmd header are not used and can be safely
removed from the driver. This patch removes that file and deletes all
relevant includes.

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

mlx5: Use refcount_t for refcount

Reference counters are preferred to use refcount_t instead of
atomic_t.
This is because the implementation of refcount_t can prevent
overflows and detect possible use-after-free.
So convert atomic_t ref counters to refcount_t.

Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Acked-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

RDMA: Handle SRQ allocations by IB/core

Convert SRQ allocation from drivers to be in the IB/core

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

mlx5: Convert mlx5_srq_table to XArray

Remove the custom spinlock as the XArray handles its own locking.

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

IB/mlx5: Fix the locking of SRQ objects in ODP events

QP and SRQ objects are stored in different containers so the action to get
and lock a common resource during ODP event needs to address that.

While here get rid of 'refcount' and 'free' fields in mlx5_core_srq struct
and use the fields with same semantics in common structure.

Fixes: 032080ab43ac ("IB/mlx5: Lock QP during page fault handling")
Signed-off-by: Moni Shoua <monis@mellanox.com>
Reviewed-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

RDMA/mlx5: Unfold modify RMP function

There is no need to perform modify_rmp in two separate function,
while one of them uses stack as a placeholder for data while other
allocates it dynamically. Combine those two functions to one call
instead of two.

Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

RDMA/mlx5: Unfold create RMP function

There is no need to perform create_rmp in two separate function, while
one of them uses stack as a placeholder for data while other allocates
it dynamically. Combine those two functions to one instead of two.

Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

RDMA/mlx5: Initialize SRQ tables on mlx5_ib

Transfer initialization and cleanup from mlx5_priv struct of
mlx5_core_dev to be part of mlx5_ib_dev. This completes removal
of SRQ from mlx5_core.

Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

RDMA/mlx5: Update SRQ functions signatures to mlx5_ib format

Reflect the change of moving SRQ code from mlx5_core to mlx5_ib by
updating function signatures do not require mlx5_core_dev as an input,
because all operations in mlx5_ib are supposed to use mlx5_ib_dev.

Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

net/mlx5: Move SRQ functions to RDMA part

There is no need to keep SRQ which is RDMA object in mlx5_core.
In this patch, we partially move the execution code, while next patches
will move table initialization/release logic too.

Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>