x86, olpc: Add support for calling into OpenFirmware

Add support for saving OFW's cif, and later calling into it to run OFW
commands.  OFW remains resident in memory, living within virtual range
0xff800000 - 0xffc00000.  A single page directory entry points to the
pgdir that OFW actually uses, so rather than saving the entire page
table, we grab and install that one entry permanently in the kernel's
page table.

This is currently only used by the OLPC XO.  Note that this particular
calling convention breaks PAE and PAT, and so cannot be used on newer
x86 hardware.

Signed-off-by: Andres Salomon <dilinger@queued.net>
LKML-Reference: <20100618174653.7755a39a@dev.queued.net>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index b4ae4acbd031..b008e7883207 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -102,6 +102,7 @@
 
 #include <asm/paravirt.h>
 #include <asm/hypervisor.h>
+#include <asm/olpc_ofw.h>
 
 #include <asm/percpu.h>
 #include <asm/topology.h>
@@ -736,10 +737,15 @@ void __init setup_arch(char **cmdline_p)
         /* VMI may relocate the fixmap; do this before touching ioremap area */
         vmi_init();
 
+        /* OFW also may relocate the fixmap */
+        olpc_ofw_detect();
+
         early_trap_init();
         early_cpu_init();
         early_ioremap_init();
 
+        setup_olpc_ofw_pgd();
+
         ROOT_DEV = old_decode_dev(boot_params.hdr.root_dev);
         screen_info = boot_params.screen_info;
         edid_info = boot_params.edid_info;