[PATCH v4] PCI: quirks: update Cavium ThunderX ACS quirk implementation

Vadim Lomovtsev
2017-09-18T08:48:01Z

This commit makes Cavium PCI ACS quirk applicable only to Cavium
ThunderX (CN81/83/88XX) PCIE Root Ports which has limited PCI capabilities
in terms of no ACS support advertisement. However, the RTL internally
implements similar protection as if ACS had completion/request redirection,
upstream forwarding and validation features enabled.

Current quirk implementation doesn't take into account PCIERCs which
also needs to be quirked. So the pci device id check mask is updated
and check of device ID moved into separate function.

Signed-off-by: Vadim Lomovtsev <Vadim.Lomovtsev@caviumnetworks.com>
---
v1 : put device check into separate function and extend it to all
Cavium PCIERC/PCCBR devices;
v1 -> v2: update match function in order to filter only ThunderX devices by device
ids to properly filter CN8XXX devices, update subject & description with
ACS register info (rejected by maillist due to triple X in subject);
v2 -> v3: update subject: remove CN8XXX from subject line, replace it with ThunderX;
v3 -> v4: update ACS mask (remove TB and TD bits), update commit message (remove
ACS register printout);

drivers/pci/quirks.c | 26 ++++++++++++++++----------
1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index a4d3361..e6b904a 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -4211,20 +4211,26 @@ static int pci_quirk_amd_sb_acs(struct pci_dev *dev, u16 acs_flags)
#endif
}

-static int pci_quirk_cavium_acs(struct pci_dev *dev, u16 acs_flags)
+/*
+ * Cavium devices matching this quirk do not perform peer-to-peer
+ * with other functions, allowing masking out these bits as if they
+ * were unimplemented in the ACS capability.
+ */
+#define CAVIUM_CN8XXX_ACS_FLAGS (PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_SV | PCI_ACS_UF)
+
+static __inline__ bool pci_quirk_cavium_acs_match(struct pci_dev *dev)
{
- /*
- * Cavium devices matching this quirk do not perform peer-to-peer
- * with other functions, allowing masking out these bits as if they
- * were unimplemented in the ACS capability.
- */
- acs_flags &= ~(PCI_ACS_SV | PCI_ACS_TB | PCI_ACS_RR |
- PCI_ACS_CR | PCI_ACS_UF | PCI_ACS_DT);
+ return (pci_is_pcie(dev) &&
+ (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) &&
+ ((dev->device & 0xf800) == 0xa000));
+}

- if (!((dev->device >= 0xa000) && (dev->device <= 0xa0ff)))
+static int pci_quirk_cavium_acs(struct pci_dev *dev, u16 acs_flags)
+{
+ if (!pci_quirk_cavium_acs_match(dev))
return -ENOTTY;

- return acs_flags ? 0 : 1;
+ return acs_flags & ~(CAVIUM_CN8XXX_ACS_FLAGS) ? 0 : 1;
}

static int pci_quirk_xgene_acs(struct pci_dev *dev, u16 acs_flags)
--
2.9.5