fix #5926: cherry-pick ACS-quirk fix from linux-stable/6.11.7

the latest linux-stable pull I found in ubuntu-oracular was for 6.11.5
- this fix here seems targeted enough. see also the discussion
upstream:
https://lore.kernel.org/all/20241029163317.GA216411@nvidia.com/

Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
This commit is contained in:
Stoiko Ivanov 2024-11-26 17:36:35 +01:00 committed by Thomas Lamprecht
parent 2519c2669d
commit 21160ccd40

View File

@ -0,0 +1,68 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Jason Gunthorpe <jgg@nvidia.com>
Date: Wed, 16 Oct 2024 20:52:33 -0300
Subject: [PATCH] PCI: Fix pci_enable_acs() support for the ACS quirks
[ Upstream commit f3c3ccc4fe49dbc560b01d16bebd1b116c46c2b4 ]
There are ACS quirks that hijack the normal ACS processing and deliver to
to special quirk code. The enable path needs to call
pci_dev_specific_enable_acs() and then pci_dev_specific_acs_enabled() will
report the hidden ACS state controlled by the quirk.
The recent rework got this out of order and we should try to call
pci_dev_specific_enable_acs() regardless of any actual ACS support in the
device.
As before command line parameters that effect standard PCI ACS don't
interact with the quirk versions, including the new config_acs= option.
Link: https://lore.kernel.org/r/0-v1-f96b686c625b+124-pci_acs_quirk_fix_jgg@nvidia.com
Fixes: 47c8846a49ba ("PCI: Extend ACS configurability")
Reported-by: Jiri Slaby <jirislaby@kernel.org>
Closes: https://lore.kernel.org/all/e89107da-ac99-4d3a-9527-a4df9986e120@kernel.org
Closes: https://bugzilla.suse.com/show_bug.cgi?id=1229019
Tested-by: Steffen Dirkwinkel <me@steffen.cc>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 8803132f857d1959f99c6ef98cf74776a52987e4)
Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
---
drivers/pci/pci.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index ffaaca0978cbc..a89436d481f07 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1067,8 +1067,15 @@ static void pci_std_enable_acs(struct pci_dev *dev, struct pci_acs *caps)
static void pci_enable_acs(struct pci_dev *dev)
{
struct pci_acs caps;
+ bool enable_acs = false;
int pos;
+ /* If an iommu is present we start with kernel default caps */
+ if (pci_acs_enable) {
+ if (pci_dev_specific_enable_acs(dev))
+ enable_acs = true;
+ }
+
pos = dev->acs_cap;
if (!pos)
return;
@@ -1077,11 +1084,8 @@ static void pci_enable_acs(struct pci_dev *dev)
pci_read_config_word(dev, pos + PCI_ACS_CTRL, &caps.ctrl);
caps.fw_ctrl = caps.ctrl;
- /* If an iommu is present we start with kernel default caps */
- if (pci_acs_enable) {
- if (pci_dev_specific_enable_acs(dev))
- pci_std_enable_acs(dev, &caps);
- }
+ if (enable_acs)
+ pci_std_enable_acs(dev, &caps);
/*
* Always apply caps from the command line, even if there is no iommu.