[patch 1/3] x86: Add early platform detection

From: Thomas Gleixner
Date: Sun Aug 30 2009 - 09:47:06 EST


Platforms like Moorestown require early setup and want to avoid the
call to reserve_ebda_region. The x86_init override is too late when
the MRST detection happens in setup_arch. Move the default i386
x86_init overrides and the call to reserve_ebda_region into a separate
function which is called as the default of a switch case depending on
the hardware_subarch id in boot params. This allows us to add a case
for MRST and let MRST have its own early setup function.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
arch/x86/include/asm/x86_init.h | 3 +--
arch/x86/kernel/head32.c | 22 +++++++++++++++++-----
arch/x86/kernel/head64.c | 3 ++-
arch/x86/kernel/x86_init.c | 1 -
4 files changed, 20 insertions(+), 9 deletions(-)

Index: linux-2.6-tip/arch/x86/include/asm/x86_init.h
===================================================================
--- linux-2.6-tip.orig/arch/x86/include/asm/x86_init.h
+++ linux-2.6-tip/arch/x86/include/asm/x86_init.h
@@ -2,6 +2,7 @@
#define _ASM_X86_PLATFORM_H

#include <asm/pgtable_types.h>
+#include <asm/bootparam.h>

struct mpc_bus;
struct mpc_cpu;
@@ -34,14 +35,12 @@ struct x86_init_mpparse {
* @probe_roms: probe BIOS roms
* @reserve_resources: reserve the standard resources for the
* platform
- * @reserve_ebda_region: reserve the extended bios data area
* @memory_setup: platform specific memory setup
*
*/
struct x86_init_resources {
void (*probe_roms)(void);
void (*reserve_resources)(void);
- void (*reserve_ebda_region)(void);
char *(*memory_setup)(void);
};

Index: linux-2.6-tip/arch/x86/kernel/head32.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/head32.c
+++ linux-2.6-tip/arch/x86/kernel/head32.c
@@ -15,6 +15,17 @@
#include <asm/trampoline.h>
#include <asm/apic.h>
#include <asm/io_apic.h>
+#include <asm/bios_ebda.h>
+
+static void __init i386_default_early_setup(void)
+{
+ /* Initilize 32bit specific setup functions */
+ x86_init.resources.probe_roms = probe_roms;
+ x86_init.resources.reserve_resources = i386_reserve_resources;
+ x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc;
+
+ reserve_ebda_region();
+}

void __init i386_start_kernel(void)
{
@@ -31,12 +42,13 @@ void __init i386_start_kernel(void)
reserve_early(ramdisk_image, ramdisk_end, "RAMDISK");
}
#endif
- /* Initilize 32bit specific setup functions */
- x86_init.resources.probe_roms = probe_roms;
- x86_init.resources.reserve_resources = i386_reserve_resources;
- x86_init.mpparse.setup_ioapic_ids = setup_ioapic_ids_from_mpc;

- x86_init.resources.reserve_ebda_region();
+ /* Call the subarch specific early setup function */
+ switch (boot_params.hdr.hardware_subarch) {
+ default:
+ i386_default_early_setup();
+ break;
+ }

/*
* At this point everything still needed from the boot loader
Index: linux-2.6-tip/arch/x86/kernel/head64.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/head64.c
+++ linux-2.6-tip/arch/x86/kernel/head64.c
@@ -24,6 +24,7 @@
#include <asm/kdebug.h>
#include <asm/e820.h>
#include <asm/trampoline.h>
+#include <asm/bios_ebda.h>

static void __init zap_identity_mappings(void)
{
@@ -111,7 +112,7 @@ void __init x86_64_start_reservations(ch
}
#endif

- x86_init.resources.reserve_ebda_region();
+ reserve_ebda_region();

/*
* At this point everything still needed from the boot loader
Index: linux-2.6-tip/arch/x86/kernel/x86_init.c
===================================================================
--- linux-2.6-tip.orig/arch/x86/kernel/x86_init.c
+++ linux-2.6-tip/arch/x86/kernel/x86_init.c
@@ -28,7 +28,6 @@ struct __initdata x86_init_ops x86_init
.resources = {
.probe_roms = x86_init_noop,
.reserve_resources = reserve_standard_io_resources,
- .reserve_ebda_region = reserve_ebda_region,
.memory_setup = default_machine_specific_memory_setup,
},



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