Pci: fixes and unit testings

[rizlik]

This PR address several problems in PCI code:

• correctly sizing of 64bit BAR
• fix bugs in error path don't restoring state correctly
• fix wrong register offset for bridge I/O window settings
• fix using the offset instead of address in pci_config_io_write16/read16
• minors

It also add unit testi to pci.c, to a coverage of 97.8%

[Copilot]

Pull request overview

This PR fixes critical bugs in the PCI enumeration code and adds comprehensive unit tests achieving 97.8% code coverage.

Changes:

• Fixed 64-bit BAR size detection by ensuring both upper and lower BAR registers are written with probe mask before reading size
• Corrected PCI bridge I/O window register offsets from incorrect 0x30/0x32 to spec-compliant 0x1C/0x1D
• Fixed I/O config space read/write functions to use offset values instead of full encoded addresses
• Added proper error path state restoration in bridge programming
• Fixed BAR restore to use correct offset (bar_off instead of bar_idx)
• Added extensive unit test infrastructure with mock PCI topology

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
tools/unit-tests/unit-pci.c	Complete rewrite with mock PCI topology infrastructure and 25+ comprehensive test cases covering all major code paths including error handling
src/pci.c	Multiple critical bug fixes: 64-bit BAR sizing, I/O window offsets, I/O config read/write offset handling, error path restoration, BAR restore offset fix, and debug output cleanup
include/pci.h	Corrected I/O base/limit register offsets and changed pci_enum_bus return type from uint32_t to int

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[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

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[dgarske]

Thank you Marco!

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated 6 comments.

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