1 files changed, 36 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 773424df828a..551f6713ff42 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -37,6 +37,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/personality.h>
 #include <linux/random.h>
+#include <linux/hw_breakpoint.h>
 
 #include <asm/pgtable.h>
 #include <asm/uaccess.h>
@@ -462,14 +463,42 @@ struct task_struct *__switch_to(struct task_struct *prev,
 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
         switch_booke_debug_regs(&new->thread);
 #else
+/*
+ * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would
+ * schedule DABR
+ */
+#ifndef CONFIG_HAVE_HW_BREAKPOINT
         if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr))
                 set_dabr(new->thread.dabr);
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
 #endif
 
 
         new_thread = &new->thread;
         old_thread = &current->thread;
 
+#if defined(CONFIG_PPC_BOOK3E_64)
+        /* XXX Current Book3E code doesn't deal with kernel side DBCR0,
+         * we always hold the user values, so we set it now.
+         *
+         * However, we ensure the kernel MSR:DE is appropriately cleared too
+         * to avoid spurrious single step exceptions in the kernel.
+         *
+         * This will have to change to merge with the ppc32 code at some point,
+         * but I don't like much what ppc32 is doing today so there's some
+         * thinking needed there
+         */
+        if ((new_thread->dbcr0 | old_thread->dbcr0) & DBCR0_IDM) {
+                u32 dbcr0;
+
+                mtmsr(mfmsr() & ~MSR_DE);
+                isync();
+                dbcr0 = mfspr(SPRN_DBCR0);
+                dbcr0 = (dbcr0 & DBCR0_EDM) | new_thread->dbcr0;
+                mtspr(SPRN_DBCR0, dbcr0);
+        }
+#endif /* CONFIG_PPC64_BOOK3E */
+
 #ifdef CONFIG_PPC64
         /*
          * Collect processor utilization data per process
@@ -642,7 +671,11 @@ void flush_thread(void)
 {
         discard_lazy_cpu_state();
 
+#ifdef CONFIG_HAVE_HW_BREAKPOINTS
+        flush_ptrace_hw_breakpoint(current);
+#else /* CONFIG_HAVE_HW_BREAKPOINTS */
         set_debug_reg_defaults(&current->thread);
+#endif /* CONFIG_HAVE_HW_BREAKPOINTS */
 }
 
 void
@@ -660,6 +693,9 @@ void prepare_to_copy(struct task_struct *tsk)
         flush_altivec_to_thread(current);
         flush_vsx_to_thread(current);
         flush_spe_to_thread(current);
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+        flush_ptrace_hw_breakpoint(tsk);
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
 }
 
 /*