linuxkpi: Add pci_iomap and pci_iounmap

[manu]

Summary

Those function are use to map/unmap io region of a pci device.
Different resource can be mapped depending on the bar so use a
tailq to store them all.

Sponsored-by: The FreeBSD Foundation
Signed-off-by: Emmanuel Vadot <[e-mail]>

Test Plan

Tested with intel drm driver
https://github.com/evadot/kms-drm/commit/657d0aa458d0d7486ed7998a47b8a618edc2031f
I'll do a patch for the 5.0 branch at FreeBSDDesktop (that will need to be cherry-picked for the 4.16 branch too).

[manu]

Add free region

[• hselasky]

Assuming the API is only used during PCI enumeration.

Don't forget to MFC!

[• hselasky]

Please also add "LinuxKPI" somewhere in the commit message.

[val_packett.cool]

will need to be cherry-picked for the 4.16 branch too

And 5.1 :)

[manu]

In D24696#543758, @hselasky wrote:

Assuming the API is only used during PCI enumeration.

Don't forget to MFC!

It's used during initialisation and teardown (so attach/detach).

[manu]

In D24696#543761, @hselasky wrote:

Please also add "LinuxKPI" somewhere in the commit message.

Review title is the first line of the commit :)

[emaste]

sys/compat/linuxkpi/common/include/linux/pci.h

682 ↗

(On Diff #71399)

For this case (only one goto fail and no fallthrough to the fail return case) it seems lines 687/688 could just be here?

700–702 ↗

(On Diff #71399)

extra wrapping?

[manu]

sys/compat/linuxkpi/common/include/linux/pci.h

682 ↗

(On Diff #71399)

true, I'll modify that.

700–702 ↗

(On Diff #71399)

that's aligned + 4 spaces, which is style(9) compliant iirc.

[emaste]

sys/compat/linuxkpi/common/include/linux/pci.h

700–702 ↗

(On Diff #71399)

but I mean why not mmio->type, mmio->rid, mmio->res); on one line?

[manu]

sys/compat/linuxkpi/common/include/linux/pci.h

700–702 ↗

(On Diff #71399)

Ah, I don't know, it's pretty ? :)
I'll change that too.