Add a new PCITEST_BAR_SUBRANGE ioctl to exercise EPC BAR subrange
mapping end-to-end.
The test programs a simple 2-subrange layout on the endpoint (via
pci-epf-test) and verifies that:
- the endpoint-provided per-subrange signature bytes are observed at
the expected PCIe BAR offsets, and
- writes to each subrange are routed to the correct backing region
(i.e. the submap order is applied rather than accidentally working
due to an identity mapping).
Return -EOPNOTSUPP when the endpoint does not advertise subrange
mapping, -ENODATA when the BAR is disabled, and -EBUSY when the BAR is
reserved for the test register space.
Signed-off-by: Koichiro Den <den@valinux.co.jp>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260124145012.2794108-8-den@valinux.co.jp
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