[RFC Patch 5/10] Use wrapper routines around debug registers in processor related functions

K.Prasad
2009-01-22T14:06:45Z

This patch enables the use of wrapper routines to access the debug/breakpoint
registers.

Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
---
arch/x86/kernel/smpboot.c | 3 +++
arch/x86/power/cpu_32.c | 16 +++-------------
arch/x86/power/cpu_64.c | 15 +++------------
3 files changed, 9 insertions(+), 25 deletions(-)

Index: linux-hbkpt-lkml-29-rc2/arch/x86/power/cpu_32.c
===================================================================
--- linux-hbkpt-lkml-29-rc2.orig/arch/x86/power/cpu_32.c
+++ linux-hbkpt-lkml-29-rc2/arch/x86/power/cpu_32.c
@@ -12,6 +12,7 @@
#include <asm/mtrr.h>
#include <asm/mce.h>
#include <asm/xcr.h>
+#include <asm/debugreg.h>

static struct saved_context saved_context;

@@ -47,6 +48,7 @@ static void __save_processor_state(struc
ctxt->cr2 = read_cr2();
ctxt->cr3 = read_cr3();
ctxt->cr4 = read_cr4_safe();
+ disable_debug_registers();
}

/* Needed by apm.c */
@@ -79,19 +81,7 @@ static void fix_processor_context(void)
load_TR_desc(); /* This does ltr */
load_LDT(&current->active_mm->context); /* This does lldt */

- /*
- * Now maybe reload the debug registers
- */
- if (current->thread.debugreg7) {
- set_debugreg(current->thread.debugreg0, 0);
- set_debugreg(current->thread.debugreg1, 1);
- set_debugreg(current->thread.debugreg2, 2);
- set_debugreg(current->thread.debugreg3, 3);
- /* no 4 and 5 */
- set_debugreg(current->thread.debugreg6, 6);
- set_debugreg(current->thread.debugreg7, 7);
- }
-
+ load_debug_registers();
}

static void __restore_processor_state(struct saved_context *ctxt)
Index: linux-hbkpt-lkml-29-rc2/arch/x86/power/cpu_64.c
===================================================================
--- linux-hbkpt-lkml-29-rc2.orig/arch/x86/power/cpu_64.c
+++ linux-hbkpt-lkml-29-rc2/arch/x86/power/cpu_64.c
@@ -15,6 +15,7 @@
#include <asm/pgtable.h>
#include <asm/mtrr.h>
#include <asm/xcr.h>
+#include <asm/debugreg.h>

static void fix_processor_context(void);

@@ -70,6 +71,7 @@ static void __save_processor_state(struc
ctxt->cr3 = read_cr3();
ctxt->cr4 = read_cr4();
ctxt->cr8 = read_cr8();
+ disable_debug_registers();
}

void save_processor_state(void)
@@ -158,16 +160,5 @@ static void fix_processor_context(void)
load_TR_desc(); /* This does ltr */
load_LDT(&current->active_mm->context); /* This does lldt */

- /*
- * Now maybe reload the debug registers
- */
- if (current->thread.debugreg7){
- loaddebug(&current->thread, 0);
- loaddebug(&current->thread, 1);
- loaddebug(&current->thread, 2);
- loaddebug(&current->thread, 3);
- /* no 4 and 5 */
- loaddebug(&current->thread, 6);
- loaddebug(&current->thread, 7);
- }
+ load_debug_registers();
}
Index: linux-hbkpt-lkml-29-rc2/arch/x86/kernel/smpboot.c
===================================================================
--- linux-hbkpt-lkml-29-rc2.orig/arch/x86/kernel/smpboot.c
+++ linux-hbkpt-lkml-29-rc2/arch/x86/kernel/smpboot.c
@@ -63,6 +63,7 @@
#include <asm/vmi.h>
#include <asm/genapic.h>
#include <asm/setup.h>
+#include <asm/debugreg.h>
#include <linux/mc146818rtc.h>

#include <mach_apic.h>
@@ -337,6 +338,7 @@ notrace static void __cpuinit start_seco
setup_secondary_clock();

wmb();
+ load_debug_registers();
cpu_idle();
}

@@ -1373,6 +1375,7 @@ void cpu_disable_common(void)
remove_cpu_from_maps(cpu);
unlock_vector_lock();
fixup_irqs();
+ disable_debug_registers();
}

int native_cpu_disable(void)