ocxl: Fix endiannes bug in read_afu_name()

The AFU Descriptor Template in the PCI config space has a Name Space
field which is a 24 Byte ASCII character string of descriptive name
space for the AFU. The OCXL driver read the string four characters at
a time with pci_read_config_dword().

This optimization is valid on a little-endian system since this is PCI,
but a big-endian system ends up with each subset of four characters in
reverse order.

This could be fixed by switching to read characters one by one. Another
option is to swap the bytes if we're big-endian.

Go for the latter with le32_to_cpu().

Cc: stable@vger.kernel.org      # v4.16
Signed-off-by: Greg Kurz <groug@kaod.org>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Acked-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/drivers/misc/ocxl/config.c b/drivers/misc/ocxl/config.c
index 57a6bb1fd3c955ec8df88ec669b58ca33efede0d..8f2c5d8bd2eee84302c0120a5f1ba06d5e5a2c5b 100644 (file)
--- a/drivers/misc/ocxl/config.c
+++ b/drivers/misc/ocxl/config.c
@@ -318,7 +318,7 @@ static int read_afu_name(struct pci_dev *dev, struct ocxl_fn_config *fn,
                if (rc)
                        return rc;
                ptr = (u32 *) &afu->name[i];
-               *ptr = val;
+               *ptr = le32_to_cpu((__force __le32) val);
        }
        afu->name[OCXL_AFU_NAME_SZ - 1] = '\0'; /* play safe */
        return 0;