powerpc: Simplify TM restore checks

Instead of having multiple giveup_*_maybe_transactional() functions,
separate out the TM check into a new function called
check_if_tm_restore_required().

This will make it easier to optimise the giveup_*() functions in a
subsequent patch.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index e098f43..ef64219 100644 (file)
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -68,7 +68,7 @@
 extern unsigned long _get_SP(void);
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
-void giveup_fpu_maybe_transactional(struct task_struct *tsk)
+static void check_if_tm_restore_required(struct task_struct *tsk)
 {
        /*
         * If we are saving the current thread's registers, and the
@@ -82,31 +82,9 @@ void giveup_fpu_maybe_transactional(struct task_struct *tsk)
                tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr;
                set_thread_flag(TIF_RESTORE_TM);
        }
-
-       giveup_fpu(tsk);
-}
-
-void giveup_altivec_maybe_transactional(struct task_struct *tsk)
-{
-       /*
-        * If we are saving the current thread's registers, and the
-        * thread is in a transactional state, set the TIF_RESTORE_TM
-        * bit so that we know to restore the registers before
-        * returning to userspace.
-        */
-       if (tsk == current && tsk->thread.regs &&
-           MSR_TM_ACTIVE(tsk->thread.regs->msr) &&
-           !test_thread_flag(TIF_RESTORE_TM)) {
-               tsk->thread.ckpt_regs.msr = tsk->thread.regs->msr;
-               set_thread_flag(TIF_RESTORE_TM);
-       }
-
-       giveup_altivec(tsk);
 }
-
 #else
-#define giveup_fpu_maybe_transactional(tsk)    giveup_fpu(tsk)
-#define giveup_altivec_maybe_transactional(tsk)        giveup_altivec(tsk)
+static inline void check_if_tm_restore_required(struct task_struct *tsk) { }
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
 
 #ifdef CONFIG_PPC_FPU
@@ -135,7 +113,8 @@ void flush_fp_to_thread(struct task_struct *tsk)
                         * to still have its FP state in the CPU registers.
                         */
                        BUG_ON(tsk != current);
-                       giveup_fpu_maybe_transactional(tsk);
+                       check_if_tm_restore_required(tsk);
+                       giveup_fpu(tsk);
                }
                preempt_enable();
        }
@@ -147,10 +126,12 @@ void enable_kernel_fp(void)
 {
        WARN_ON(preemptible());
 
-       if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
-               giveup_fpu_maybe_transactional(current);
-       else
+       if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) {
+               check_if_tm_restore_required(current);
+               giveup_fpu(current);
+       } else {
                giveup_fpu(NULL);       /* just enables FP for kernel */
+       }
 }
 EXPORT_SYMBOL(enable_kernel_fp);
 
@@ -159,10 +140,12 @@ void enable_kernel_altivec(void)
 {
        WARN_ON(preemptible());
 
-       if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
-               giveup_altivec_maybe_transactional(current);
-       else
+       if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) {
+               check_if_tm_restore_required(current);
+               giveup_altivec(current);
+       } else {
                giveup_altivec_notask();
+       }
 }
 EXPORT_SYMBOL(enable_kernel_altivec);
 
@@ -176,7 +159,8 @@ void flush_altivec_to_thread(struct task_struct *tsk)
                preempt_disable();
                if (tsk->thread.regs->msr & MSR_VEC) {
                        BUG_ON(tsk != current);
-                       giveup_altivec_maybe_transactional(tsk);
+                       check_if_tm_restore_required(tsk);
+                       giveup_altivec(tsk);
                }
                preempt_enable();
        }
@@ -198,8 +182,9 @@ EXPORT_SYMBOL(enable_kernel_vsx);
 
 void giveup_vsx(struct task_struct *tsk)
 {
-       giveup_fpu_maybe_transactional(tsk);
-       giveup_altivec_maybe_transactional(tsk);
+       check_if_tm_restore_required(tsk);
+       giveup_fpu(tsk);
+       giveup_altivec(tsk);
        __giveup_vsx(tsk);
 }
 EXPORT_SYMBOL(giveup_vsx);