From 15cf508331ef025c55ad5759517584232a6792fc Mon Sep 17 00:00:00 2001
From: =?utf8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
Date: Wed, 24 Nov 2021 16:59:39 +0100
Subject: [PATCH] PCI: pci-bridge-emul: Make expansion ROM Base Address
register read-only
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commit 1c1a3b4d3e86b997a313ffb297c1129540882859 upstream.
If expansion ROM is unsupported (which is the case of pci-bridge-emul.c
driver) then ROM Base Address register must be implemented as read-only
register that return 0 when read, same as for unused Base Address
registers.
Link: https://lore.kernel.org/r/20211124155944.1290-2-pali@kernel.org
Fixes: 23a5fba4d941 ("PCI: Introduce PCI bridge emulated config space common logic")
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/pci/pci-bridge-emul.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/pci-bridge-emul.c b/drivers/pci/pci-bridge-emul.c
index db97cddfc85e1..5de8b8dde2093 100644
--- a/drivers/pci/pci-bridge-emul.c
+++ b/drivers/pci/pci-bridge-emul.c
@@ -139,8 +139,13 @@ struct pci_bridge_reg_behavior pci_regs_behavior[PCI_STD_HEADER_SIZEOF / 4] = {
.ro = GENMASK(7, 0),
},
+ /*
+ * If expansion ROM is unsupported then ROM Base Address register must
+ * be implemented as read-only register that return 0 when read, same
+ * as for unused Base Address registers.
+ */
[PCI_ROM_ADDRESS1 / 4] = {
- .rw = GENMASK(31, 11) | BIT(0),
+ .ro = ~0,
},
/*
--
2.30.2