pci root complex: support for tile architecture
This change enables PCI root complex support for TILEPro. Unlike
TILE-Gx, TILEPro has no support for memory-mapped I/O, so the PCI
support consists of hypervisor upcalls for PIO, DMA, etc. However,
the performance is fine for the devices we have tested with so far
(1Gb Ethernet, SATA, etc.).
The <asm/io.h> header was tweaked to be a little bit more aggressive
about disabling attempts to map/unmap IO port space. The hacky
<asm/pci-bridge.h> header was rolled into the <asm/pci.h> header
and the result was simplified. Both of the latter two headers were
preliminary versions not meant for release before now - oh well.
There is one quirk for our TILEmpower platform, which accidentally
negotiates up to 5GT and needs to be kicked down to 2.5GT.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 07ec8a8..e11b5fc 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -329,6 +329,18 @@
menu "Bus options"
+config PCI
+ bool "PCI support"
+ default y
+ select PCI_DOMAINS
+ ---help---
+ Enable PCI root complex support, so PCIe endpoint devices can
+ be attached to the Tile chip. Many, but not all, PCI devices
+ are supported under Tilera's root complex driver.
+
+config PCI_DOMAINS
+ bool
+
config NO_IOMEM
def_bool !PCI