[PATCH 4.14 153/190] PCI: Make ACS quirk implementations more uniform

Greg Kroah-Hartman
2020-06-19T14:51:45Z

From: Bjorn Helgaas <bhelgaas@google.com>

[ Upstream commit c8de8ed2dcaac82e5d76d467dc0b02e0ee79809b ]

The ACS quirks differ in needless ways, which makes them look more
different than they really are.

Reorder the ACS flags in order of definitions in the spec:

PCI_ACS_SV Source Validation
PCI_ACS_TB Translation Blocking
PCI_ACS_RR P2P Request Redirect
PCI_ACS_CR P2P Completion Redirect
PCI_ACS_UF Upstream Forwarding
PCI_ACS_EC P2P Egress Control
PCI_ACS_DT Direct Translated P2P

(PCIe r5.0, sec 7.7.8.2) and use similar code structure in all. No
functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/pci/quirks.c | 41 +++++++++++++++++++----------------------
1 file changed, 19 insertions(+), 22 deletions(-)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 81d76e34b0db..44be840dac0d 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4305,18 +4305,18 @@ static bool pci_quirk_cavium_acs_match(struct pci_dev *dev)

static int pci_quirk_cavium_acs(struct pci_dev *dev, u16 acs_flags)
{
+ if (!pci_quirk_cavium_acs_match(dev))
+ return -ENOTTY;
+
/*
- * Cavium root ports don't advertise an ACS capability. However,
+ * Cavium Root Ports don't advertise an ACS capability. However,
* the RTL internally implements similar protection as if ACS had
- * Request Redirection, Completion Redirection, Source Validation,
+ * Source Validation, Request Redirection, Completion Redirection,
* and Upstream Forwarding features enabled. Assert that the
* hardware implements and enables equivalent ACS functionality for
* these flags.
*/
- acs_flags &= ~(PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_SV | PCI_ACS_UF);
-
- if (!pci_quirk_cavium_acs_match(dev))
- return -ENOTTY;
+ acs_flags &= ~(PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);

return acs_flags ? 0 : 1;
}
@@ -4334,7 +4334,7 @@ static int pci_quirk_xgene_acs(struct pci_dev *dev, u16 acs_flags)
}

/*
- * Many Intel PCH root ports do provide ACS-like features to disable peer
+ * Many Intel PCH Root Ports do provide ACS-like features to disable peer
* transactions and validate bus numbers in requests, but do not provide an
* actual PCIe ACS capability. This is the list of device IDs known to fall
* into that category as provided by Intel in Red Hat bugzilla 1037684.
@@ -4382,37 +4382,34 @@ static bool pci_quirk_intel_pch_acs_match(struct pci_dev *dev)
return false;
}

-#define INTEL_PCH_ACS_FLAGS (PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_SV)
+#define INTEL_PCH_ACS_FLAGS (PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF)

static int pci_quirk_intel_pch_acs(struct pci_dev *dev, u16 acs_flags)
{
- u16 flags = dev->dev_flags & PCI_DEV_FLAGS_ACS_ENABLED_QUIRK ?
- INTEL_PCH_ACS_FLAGS : 0;
-
if (!pci_quirk_intel_pch_acs_match(dev))
return -ENOTTY;

- return acs_flags & ~flags ? 0 : 1;
+ if (dev->dev_flags & PCI_DEV_FLAGS_ACS_ENABLED_QUIRK)
+ acs_flags &= ~(INTEL_PCH_ACS_FLAGS);
+
+ return acs_flags ? 0 : 1;
}

/*
- * These QCOM root ports do provide ACS-like features to disable peer
+ * These QCOM Root Ports do provide ACS-like features to disable peer
* transactions and validate bus numbers in requests, but do not provide an
* actual PCIe ACS capability. Hardware supports source validation but it
* will report the issue as Completer Abort instead of ACS Violation.
- * Hardware doesn't support peer-to-peer and each root port is a root
- * complex with unique segment numbers. It is not possible for one root
- * port to pass traffic to another root port. All PCIe transactions are
- * terminated inside the root port.
+ * Hardware doesn't support peer-to-peer and each Root Port is a Root
+ * Complex with unique segment numbers. It is not possible for one Root
+ * Port to pass traffic to another Root Port. All PCIe transactions are
+ * terminated inside the Root Port.
*/
static int pci_quirk_qcom_rp_acs(struct pci_dev *dev, u16 acs_flags)
{
- u16 flags = (PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_SV);
- int ret = acs_flags & ~flags ? 0 : 1;
-
- dev_info(&dev->dev, "Using QCOM ACS Quirk (%d)\n", ret);
+ acs_flags &= ~(PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF);

- return ret;
+ return acs_flags ? 0 : 1;
}

/*
--
2.25.1