[PATCH 4.2.y-ckt 009/268] cxl: use correct operator when writing pcie config space values

From: Kamal Mostafa
Date: Wed Jan 27 2016 - 17:00:55 EST

4.2.8-ckt3 -stable review patch. If anyone has any objections, please let me know.


From: Andrew Donnellan <andrew.donnellan@xxxxxxxxxxx>

commit 48f0f6b717e314a30be121b67e1d044f6d311d66 upstream.

When writing a value to config space, cxl_pcie_write_config() calls
cxl_pcie_config_info() to obtain a mask and shift value, shifts the new
value accordingly, then uses the mask to combine the shifted value with the
existing value at the address as part of a read-modify-write pattern.

Currently, we use a logical OR operator rather than a bitwise OR operator,
which means any use of this function results in an incorrect value being
written. Replace the logical OR operator with a bitwise OR operator so the
value is written correctly.

Reported-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Fixes: 6f7f0b3df6d4 ("cxl: Add AFU virtual PHB and kernel API")
Signed-off-by: Andrew Donnellan <andrew.donnellan@xxxxxxxxxxx>
Acked-by: Ian Munsie <imunsie@xxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
drivers/misc/cxl/vphb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/misc/cxl/vphb.c b/drivers/misc/cxl/vphb.c
index 2eba002..15f154e 100644
--- a/drivers/misc/cxl/vphb.c
+++ b/drivers/misc/cxl/vphb.c
@@ -171,7 +171,7 @@ static int cxl_pcie_write_config(struct pci_bus *bus, unsigned int devfn,
mask <<= shift;
val <<= shift;

- v = (in_le32(ioaddr) & ~mask) || (val & mask);
+ v = (in_le32(ioaddr) & ~mask) | (val & mask);

out_le32(ioaddr, v);