parport_pc: Avoid FIFO port location truncation

[ Upstream commit ab126f51c9 ]

Match the data type of a temporary holding a reference to the FIFO port
with the type of the original reference coming from `struct parport',
avoiding data truncation with LP64 ports such as SPARC64 that refer to
PCI port I/O locations via their corresponding MMIO addresses and will
therefore have non-zero bits in the high 32-bit part of the reference.
And in any case it is cleaner to have the data types matching here.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Link: https://lore.kernel.org/linux-pci/20220419033752.GA1101844@bhelgaas/
Acked-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Link: https://lore.kernel.org/r/alpine.DEB.2.21.2209231912550.29493@angie.orcam.me.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/parport/parport_pc.c

@@ -468,7 +468,7 @@ static size_t parport_pc_fifo_write_block_pio(struct parport *port,
 	const unsigned char *bufp = buf;
 	size_t left = length;
 	unsigned long expire = jiffies + port->physport->cad->timeout;
-	const int fifo = FIFO(port);
+	const unsigned long fifo = FIFO(port);
 	int poll_for = 8; /* 80 usecs */
 	const struct parport_pc_private *priv = port->physport->private_data;
 	const int fifo_depth = priv->fifo_depth;