Re: [PATCH v1] PCI: endpoint: Skip upper halves of 64-bit BARs during search

[sashiko-bot@kernel.org]

> pci_epc_get_next_free_bar() skips the upper half of a 64-bit BAR only
> when it is the starting BAR. If the search subsequently passes a
> reserved or disabled 64-bit BAR, it can return its upper half as an
> independent BAR because that slot has a default programmable descriptor.
> 
> For example, Tegra exposes a programmable 64-bit BAR0 and reserved
> 64-bit BAR2 and BAR4. A search starting at BAR1 skips BAR1 and BAR2,
> then incorrectly returns BAR3. The next search can similarly return
> BAR5, causing the EPF test driver to allocate and program BARs that
> belong to the reserved hardware windows.
> 
> Check each candidate's preceding descriptor inside the search loop so
> upper halves are skipped throughout the search. With the Tegra layout,
> BAR0 is the only available BAR and subsequent searches return NO_BAR.
> 
> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>

Sashiko has reviewed this patch and found no issues.

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Sashiko AI review · https://sashiko.dev/#/patchset/20261021080644.1346549-1-mmaddireddy@nvidia.com?part=1