Messages in this thread | | | Subject | Re: [PATCH v4 5/5] PCI: Handle Enhanced Allocation (EA) capability for bridges | From | David Daney <> | Date | Mon, 5 Oct 2015 16:01:45 -0700 |
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On 10/05/2015 03:54 PM, Sean O. Stalley wrote: > On Fri, Oct 02, 2015 at 03:37:56PM -0700, David Daney wrote: >> From: David Daney <david.daney@cavium.com> >> >> 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@cavium.com> >> --- >> 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; > } >
Yes, that is cleaner. I think I didn't read the comments on v3 closely enough. I will switch to doing it this way.
Thanks, David Daney
> > -Sean >
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