task #29600094

commit 984998e3404e9073479281dbba8af36b104e8c00 upstream.
Backport summary: for 4.19 kernel ICX PCIe Gen4 support.

pcie_downstream_port() is useful in other places where code needs to
determine whether the PCIe port is downstream so make it available outside
of access.c.

Link: https://lore.kernel.org/r/20190822085553.62697-1-mika.westerberg@linux.intel.comSigned-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
(cherry picked from commit 984998e3404e9073479281dbba8af36b104e8c00)
Signed-off-by: NEthan Zhao <haifeng.zhao@intel.com>
Signed-off-by: NArtie Ding <artie.ding@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>