This is a note to let you know that I've just added the patch titled
PCI: pci-bridge-emul: Fix definitions of reserved bits
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pci-pci-bridge-emul-fix-definitions-of-reserved-bits.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 12998087d9f48b66965b97412069c7826502cd7e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@xxxxxxxxxx>
Date: Wed, 24 Nov 2021 16:59:42 +0100
Subject: PCI: pci-bridge-emul: Fix definitions of reserved bits
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From: Pali Rohár <pali@xxxxxxxxxx>
commit 12998087d9f48b66965b97412069c7826502cd7e upstream.
Some bits in PCI_EXP registers are reserved for non-root ports. Driver
pci-bridge-emul.c implements PCIe Root Port device therefore it should not
allow setting reserved bits of registers.
Properly define non-reserved bits for all PCI_EXP registers.
Link: https://lore.kernel.org/r/20211124155944.1290-5-pali@xxxxxxxxxx
Fixes: 23a5fba4d941 ("PCI: Introduce PCI bridge emulated config space common logic")
Signed-off-by: Pali Rohár <pali@xxxxxxxxxx>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/pci/pci-bridge-emul.c | 36 +++++++++++++++++++++++++-----------
1 file changed, 25 insertions(+), 11 deletions(-)
--- a/drivers/pci/pci-bridge-emul.c
+++ b/drivers/pci/pci-bridge-emul.c
@@ -176,41 +176,55 @@ struct pci_bridge_reg_behavior pcie_cap_
[PCI_CAP_LIST_ID / 4] = {
/*
* Capability ID, Next Capability Pointer and
- * Capabilities register are all read-only.
+ * bits [14:0] of Capabilities register are all read-only.
+ * Bit 15 of Capabilities register is reserved.
*/
- .ro = ~0,
+ .ro = GENMASK(30, 0),
},
[PCI_EXP_DEVCAP / 4] = {
- .ro = ~0,
+ /*
+ * Bits [31:29] and [17:16] are reserved.
+ * Bits [27:18] are reserved for non-upstream ports.
+ * Bits 28 and [14:6] are reserved for non-endpoint devices.
+ * Other bits are read-only.
+ */
+ .ro = BIT(15) | GENMASK(5, 0),
},
[PCI_EXP_DEVCTL / 4] = {
- /* Device control register is RW */
- .rw = GENMASK(15, 0),
+ /*
+ * Device control register is RW, except bit 15 which is
+ * reserved for non-endpoints or non-PCIe-to-PCI/X bridges.
+ */
+ .rw = GENMASK(14, 0),
/*
* Device status register has bits 6 and [3:0] W1C, [5:4] RO,
- * the rest is reserved
+ * the rest is reserved. Also bit 6 is reserved for non-upstream
+ * ports.
*/
- .w1c = (BIT(6) | GENMASK(3, 0)) << 16,
+ .w1c = GENMASK(3, 0) << 16,
.ro = GENMASK(5, 4) << 16,
},
[PCI_EXP_LNKCAP / 4] = {
- /* All bits are RO, except bit 23 which is reserved */
- .ro = lower_32_bits(~BIT(23)),
+ /*
+ * All bits are RO, except bit 23 which is reserved and
+ * bit 18 which is reserved for non-upstream ports.
+ */
+ .ro = lower_32_bits(~(BIT(23) | PCI_EXP_LNKCAP_CLKPM)),
},
[PCI_EXP_LNKCTL / 4] = {
/*
* Link control has bits [15:14], [11:3] and [1:0] RW, the
- * rest is reserved.
+ * rest is reserved. Bit 8 is reserved for non-upstream ports.
*
* Link status has bits [13:0] RO, and bits [15:14]
* W1C.
*/
- .rw = GENMASK(15, 14) | GENMASK(11, 3) | GENMASK(1, 0),
+ .rw = GENMASK(15, 14) | GENMASK(11, 9) | GENMASK(7, 3) | GENMASK(1, 0),
.ro = GENMASK(13, 0) << 16,
.w1c = GENMASK(15, 14) << 16,
},
Patches currently in stable-queue which might be from pali@xxxxxxxxxx are
queue-5.15/pci-pci-bridge-emul-make-expansion-rom-base-address-register-read-only.patch
queue-5.15/pci-pci-bridge-emul-fix-definitions-of-reserved-bits.patch
queue-5.15/pci-pci-bridge-emul-correctly-set-pcie-capabilities.patch
queue-5.15/pci-pci-bridge-emul-properly-mark-reserved-pcie-bits-in-pci-config-space.patch
queue-5.15/pci-pci-bridge-emul-set-pci_status_cap_list-for-pcie-device.patch
queue-5.15/arm-dts-armada-38x-add-generic-compatible-to-uart-no.patch
