The virtio framework uses wmb() when updating avail->idx. It
guarantees the write order, but not necessarily loading order
for the code accessing the memory. This commit adds a load barrier
after reading the avail->idx to make sure all the data in the
descriptor is visible. It also adds a barrier when returning the
packet to virtio framework to make sure read/writes are visible to
the virtio code.
Fixes: 1357dfd726 ("platform/mellanox: Add TmFifo driver for Mellanox BlueField Soc")
Signed-off-by: Liming Sun <limings@nvidia.com>
Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>
Link: https://lore.kernel.org/r/1620433812-17911-1-git-send-email-limings@nvidia.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
mlxbf-tmfifo accesses config space using native types -
which works for it since the legacy virtio native types.
This will break if it ever needs to support modern virtio,
so with new tags previously introduced for virtio net config,
sparse now warns for this in drivers.
Since this is a legacy only device, fix it up using
virtio_legacy_is_little_endian for now.
No functional changes.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
This commit fixes the potential deadlock caused by the console Rx
and Tx processing at the same time. Rx and Tx both take the console
and tmfifo spinlock but in different order which causes potential
deadlock. The fix is to use different tmfifo spinlock for Rx and
Tx since they protect different resources and it's safe to split
the lock.
Below is the reported call trace when copying/pasting large string
in the console.
Rx:
_raw_spin_lock_irqsave (hvc lock)
__hvc_poll
hvc_poll
in_intr
vring_interrupt
mlxbf_tmfifo_rxtx_one_desc (tmfifo lock)
mlxbf_tmfifo_rxtx
mlxbf_tmfifo_work_rxtx
Tx:
_raw_spin_lock_irqsave (tmfifo lock)
mlxbf_tmfifo_virtio_notify
virtqueue_notify
virtqueue_kick
put_chars
hvc_push
hvc_write (hvc lock)
...
do_tty_write
tty_write
Fixes: 1357dfd726 ("platform/mellanox: Add TmFifo driver for Mellanox BlueField Soc")
Cc: <stable@vger.kernel.org> # 5.4+
Reviewed-by: David Woods <dwoods@mellanox.com>
Signed-off-by: Liming Sun <lsun@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
This commit adds the TmFifo platform driver for Mellanox BlueField
Soc. TmFifo is a shared FIFO which enables external host machine
to exchange data with the SoC via USB or PCIe. The driver is based
on virtio framework and has console and network access enabled.
Reviewed-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Liming Sun <lsun@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
