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@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;
}
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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