From f3c3ccc4fe49dbc560b01d16bebd1b116c46c2b4 Mon Sep 17 00:00:00 2001 From: Jason Gunthorpe Date: Wed, 16 Oct 2024 20:52:33 -0300 Subject: [PATCH] PCI: Fix pci_enable_acs() support for the ACS quirks 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 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 Signed-off-by: Jason Gunthorpe Signed-off-by: Bjorn Helgaas --- 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 7d85c04fbba2..225a6cd2e9ca 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.