Hi Ralf, et al,
Lorenzo is doing some nice cleanup of the PCI_PROBE_ONLY case. Previous
situation:
- PCI_PROBE_ONLY: all PCI BARs and windows are immutable, and we don't
put those resources in the iomem_resource tree, and they don't show up
in /proc/iomem.
- !PCI_PROBE_ONLY: we use whatever existing BAR settings may have been
done by firmware, we change them if we find conflicts, and we insert
them all in the iomem_resource tree.
Lorenzo is changing the PCI_PROBE_ONLY case so the BARs and windows remain
immutable, but we insert the resources into the iomem_resource tree.
The ideal thing would be to remove the use of PCI_PROBE_ONLY completely,
and allow Linux to program BARs as necessary. If the firmware *has*
programmed the BARs, we don't change them unless we find something broken,
so in most cases PCI_PROBE_ONLY is unnecessary.
There are several MIPS platforms (bcm1480, ip27, sb1250, virtio_guest, xlp,
xlr) that set PCI_PROBE_ONLY for reasons I don't know. These were added
by:
bcm1480
Andrew Isaacson <adi@xxxxxxxxxxxx>
dc41f94f7709 ("Support for the BCM1480 on-chip PCI-X bridge.")
ip27
Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
96173a6c4ebc ("[MIPS] IP27: misc fixes")
virtio
David Daney <david.daney@xxxxxxxxxx>
ae6e7e635c2c ("MIPS: paravirt: Add pci controller for virtio")
xlp
Ganesan Ramalingam <ganesanr@xxxxxxxxxxxxxxxxx>
9bac624b0fe0 ("MIPS: Netlogic: XLP PCIe controller support.")
xlr
Jayachandran C <jayachandranc@xxxxxxxxxxxxxxxxx>
9b130f8004e5 ("MIPS: XLR, XLS: Add PCI support.")
I suspect some of these uses are copied and not actually necessary. If we
need to keep them, that's fine, but I would like to at least insert the
resources into the tree, as with the following patch.
Any thoughts on this would be appreciated.
The whole series as I propose to merge it is on my pci/resource branch
at [2].
[1] http://lkml.kernel.org/r/1465383890-13538-1-git-send-email-lorenzo.pieralisi@xxxxxxx
[2] https://git.kernel.org/cgit/linux/kernel/git/helgaas/pci.git/log/?h=pci/resource
---
Bjorn Helgaas (1):
MIPS/PCI: Claim bus resources on PCI_PROBE_ONLY set-ups
arch/mips/pci/pci.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
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