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Many places in the kernel write the Link Control and Root Control PCI Express Capability Registers without proper concurrency control and this could result in losing the changes one of the writers intended to make. Add pcie_cap_lock spinlock into the struct pci_dev and use it to protect bit changes made in the RMW capability accessors. Protect only a selected set of registers by differentiating the RMW accessor internally to locked/unlocked variants using a wrapper which has the same signature as pcie_capability_clear_and_set_word(). As the Capability Register (pos) given to the wrapper is always a constant, the compiler should be able to simplify all the dead-code away. So far only the Link Control Register (ASPM, hotplug, link retraining, various drivers) and the Root Control Register (AER & PME) seem to require RMW locking. Suggested-by: Lukas Wunner <lukas@wunner.de> Fixes: |
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| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| drm | ||
| dt-bindings | ||
| keys | ||
| kunit | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| rv | ||
| scsi | ||
| soc | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| ufs | ||
| vdso | ||
| video | ||
| xen | ||