[S] Change in coreboot[master]: device/Kconfig: Reduce PCIe hotplug bus numbers and IO resources

[Arthur Heymans (Code Review)]

Arthur Heymans has uploaded this change for review. ( https://review.coreboot.org/c/coreboot/+/74774 )

Change subject: device/Kconfig: Reduce PCIe hotplug bus numbers and IO resources
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device/Kconfig: Reduce PCIe hotplug bus numbers and IO resources

The rationale behind this change is that multiple nested bridges using a
lot of bus numbers and IO resources is not likely to be a common setup.
When there is a large amount of hotplug ports using 32 subordinate
busses results in boot failures (e.g. make qemu). 8K IO busses for
hotplug devices is also excessive in most use cases when only 64K is
available in total (again make qemu results in failure to allocate
resources but does boot to payload).

Signed-off-by: Arthur Heymans 
Change-Id: I8371958037d479e7d2053f49814735e15461ca6e
---
M src/device/Kconfig
1 file changed, 22 insertions(+), 6 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/74/74774/1

diff --git a/src/device/Kconfig b/src/device/Kconfig
index ef73c40..27d2419 100644
--- a/src/device/Kconfig
+++ b/src/device/Kconfig
@@ -703,12 +703,10 @@

config PCIEXP_HOTPLUG_BUSES
    int "PCI Express Hotplug Buses"
-	default  8 if ECAM_MMCONF_SUPPORT && ECAM_MMCONF_BUS_NUMBER <=  64
-	default 16 if ECAM_MMCONF_SUPPORT && ECAM_MMCONF_BUS_NUMBER <= 128
-	default 32
+	default 8
    help
      This is the number of buses allocated for hotplug PCI express
-	  bridges, for use by hotplugged child devices. The default is 32
+	  bridges, for use by hotplugged child devices. The default is 8
      buses.

config PCIEXP_HOTPLUG_MEM
@@ -745,11 +743,11 @@

config PCIEXP_HOTPLUG_IO
    hex "PCI Express Hotplug I/O Space"
-	default 0x2000
+	default 0x800
    help
      This is the amount of I/O space to allocate to hot-plug PCI
      express bridges, for use by hotplugged child devices. The default
-	  is 8 KiB.
+	  is 2 KiB.

endif # PCIEXP_HOTPLUG