When bit4 is set in the PCIe Device Control register, it indicates whether the device is permitted to use relaxed ordering. On some platforms using relaxed ordering can have performance issues or due to erratum can cause data-corruption. In such cases devices must avoid using relaxed ordering. The patch adds a new flag PCI_DEV_FLAGS_NO_RELAXED_ORDERING to indicate that Relaxed Ordering (RO) attribute should not be used for Transaction Layer Packets (TLP) targeted towards these affected root complexes. This patch checks if there is any node in the hierarchy that indicates that using relaxed ordering is not safe. In such cases the patch turns off the relaxed ordering by clearing the capability for this device.
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| @@ -188,6 +188,8 @@ enum pci_dev_flags { · 187 unmodified lines | ||
| 188 | 188 | * the direct_complete optimization. |
| 189 | 189 | */ |
| 190 | 190 | PCI_DEV_FLAGS_NEEDS_RESUME = (__force pci_dev_flags_t) (1 << 11), |
| 191 | + /* Don't use Relaxed Ordering for TLPs directed at this device */ | |
| 192 | + PCI_DEV_FLAGS_NO_RELAXED_ORDERING = (__force pci_dev_flags_t) (1 << 12), | |
| 191 | 193 | }; |
| 192 | 194 | |
| 193 | 195 | enum pci_irq_reroute_variant { |
| @@ -1125,6 +1127,7 @@ bool pci_check_pme_status(struct pci_dev *dev); · 931 unmodified lines | ||
| 1125 | 1127 | void pci_pme_wakeup_bus(struct pci_bus *bus); |
| 1126 | 1128 | void pci_d3cold_enable(struct pci_dev *dev); |
| 1127 | 1129 | void pci_d3cold_disable(struct pci_dev *dev); |
| 1130 | +bool pcie_relaxed_ordering_enabled(struct pci_dev *dev); | |
| 1128 | 1131 | |
| 1129 | 1132 | /* PCI Virtual Channel */ |
| 1130 | 1133 | int pci_save_vc_state(struct pci_dev *dev); |