On Fri, Oct 02, 2015 at 03:37:56PM -0700, David Daney wrote:
> From: David Daney <david.daney@xxxxxxxxxx>
>
> PCI bridges may have their properties be specified via EA entries.
>
> Extend the EA parser to extract the bridge resources, and modify
> pci_read_bridge_{io,mmio,mmio_pref}() to use resources previously
> obtained via EA.
>
> Save the offset to the EA capability in struct pci_dev, and use it to
> easily find the EA bridge subordinate and secondary bus numbers.
>
> When assigning the bridge resources a couple of changes are required
> so that the EA obtained IORESOURCE_PCI_FIXED are not resized, and
> correctly linked into the resource tree.
>
> 1) In pbus_size_mem() do not attempt to resize the bridge resources if
> they are marked as IORESOURCE_PCI_FIXED.
>
> 2) In pci_bus_alloc_from_region()for IORESOURCE_PCI_FIXED resources, just
> try to request the resource as is, without attempting to resize it.
>
> Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
> ---
> drivers/pci/bus.c | 7 +++++++
> drivers/pci/pci.c | 13 +++++++++++++
> drivers/pci/probe.c | 31 +++++++++++++++++++++++++++++--
> drivers/pci/setup-bus.c | 3 +++
> include/linux/pci.h | 1 +
> 5 files changed, 53 insertions(+), 2 deletions(-)
> @@ -801,8 +813,23 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
>
> pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses);
> primary = buses & 0xFF;
> - secondary = (buses >> 8) & 0xFF;
> - subordinate = (buses >> 16) & 0xFF;
> + if (dev->ea_cap) {
> + u32 dw1;
> +
> + pci_read_config_dword(dev, dev->ea_cap + 4, &dw1);
> + if (dw1 & 0xFF)
> + secondary = dw1 & 0xFF;
> + else
> + secondary = (buses >> 8) & 0xFF;
> +
> + if ((dw1 >> 8) & 0xFF)
> + subordinate = (dw1 >> 8) & 0xFF;
> + else
> + subordinate = (buses >> 16) & 0xFF;
> + } else {
> + secondary = (buses >> 8) & 0xFF;
> + subordinate = (buses >> 16) & 0xFF;
> + }
We can refactor this to make it cleaner/more compact. from V3 review:
secondary = (buses >> 8) & 0xFF;
subordinate = (buses >> 16) & 0xFF;
if (dev->ea_cap) {
u32 sdw;
pci_read_config_dword(dev, dev->ea_cap + 4, &sdw);
if (sdw & 0xFF)
secondary = sdw & 0xFF;
sdw >>= 8;
if (sdw & 0xFF)
subordinate = sdw & 0xFF;
}
-Sean
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