linux-kernel - [PATCH 4.4 162/342] cxl: use correct operator when writing pcie config space values

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Message-Id: <20160301234533.203381654@linuxfoundation.org>
Date:	Tue, 01 Mar 2016 23:54:38 +0000
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	<linux-kernel@...r.kernel.org>
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	<stable@...r.kernel.org>, Michael Ellerman <mpe@...erman.id.au>,
	Andrew Donnellan <andrew.donnellan@....ibm.com>,
	Ian Munsie <imunsie@....ibm.com>
Subject: [PATCH 4.4 162/342] cxl: use correct operator when writing pcie config space values

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

------------------

From: Andrew Donnellan <andrew.donnellan@....ibm.com>

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@...erman.id.au>
Fixes: 6f7f0b3df6d4 ("cxl: Add AFU virtual PHB and kernel API")
Signed-off-by: Andrew Donnellan <andrew.donnellan@....ibm.com>
Acked-by: Ian Munsie <imunsie@....ibm.com>
Signed-off-by: Michael Ellerman <mpe@...erman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/misc/cxl/vphb.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/misc/cxl/vphb.c
+++ b/drivers/misc/cxl/vphb.c
@@ -203,7 +203,7 @@ static int cxl_pcie_write_config(struct
 	mask <<= shift;
 	val <<= shift;

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

 	out_le32(ioaddr, v);
 	return PCIBIOS_SUCCESSFUL;