6.11-stable review patch. If anyone has any objections, please let me know.
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From: Jason Gunthorpe jgg@nvidia.com
[ 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... 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 --- 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 85ced6958d6d1..51407c376a222 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.