Merge tag 'tegra-soc2' of git://git.kernel.org/pub/scm/linux/kernel/git/olof/tegra into tegra/soc2

From: Olof Johansson <olof@lixom.net>
Tegra 30 SMP support

I did this as a separate topic branch because it depends on both the
soc and the soc-drivers branch, so it brings both of those in as a base.

This branch contains work to enable SMP support on Tegra30 and reworks
some of the SMP bringup for T20 as well.

It also contains a device tree patch that builds on top of the SMP/clock
changes in the rest of the branch, so it made more sense to apply it
here than deal with the merge conflicts back and forth.

* tag 'tegra-soc2' of git://git.kernel.org/pub/scm/linux/kernel/git/olof/tegra:
  ARM: dt: Explicitly configure all serial ports on Tegra Cardhu
  ARM: tegra: support for secondary cores on Tegra30
  ARM: tegra: support for Tegra30 CPU powerdomains
  ARM: tegra: add support for Tegra30 powerdomains
  ARM: tegra: export tegra_powergate_is_powered()
  ARM: tegra: prepare powergate.c for multiple variants
  ARM: tegra: rework Tegra secondary CPU core bringup
  ARM: tegra: functions to access the flowcontroller
  ARM: tegra: initialize Tegra chipid early
  ARM: tegra: export Tegra chipid
  ARM: tegra: cleanup use of chipid register

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 14 insertions, 29 deletions

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 482ec3af2067..4bbe04d96744 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -571,41 +571,18 @@ asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void)
 }
 
 /*
- * __math_state_restore assumes that cr0.TS is already clear and the
- * fpu state is all ready for use.  Used during context switch.
- */
-void __math_state_restore(void)
-{
-	struct thread_info *thread = current_thread_info();
-	struct task_struct *tsk = thread->task;
-
-	/*
-	 * Paranoid restore. send a SIGSEGV if we fail to restore the state.
-	 */
-	if (unlikely(restore_fpu_checking(tsk))) {
-		stts();
-		force_sig(SIGSEGV, tsk);
-		return;
-	}
-
-	thread->status |= TS_USEDFPU;	/* So we fnsave on switch_to() */
-	tsk->fpu_counter++;
-}
-
-/*
  * 'math_state_restore()' saves the current math information in the
  * old math state array, and gets the new ones from the current task
  *
  * Careful.. There are problems with IBM-designed IRQ13 behaviour.
  * Don't touch unless you *really* know how it works.
  *
- * Must be called with kernel preemption disabled (in this case,
- * local interrupts are disabled at the call-site in entry.S).
+ * Must be called with kernel preemption disabled (eg with local
+ * local interrupts as in the case of do_device_not_available).
  */
-asmlinkage void math_state_restore(void)
+void math_state_restore(void)
 {
-	struct thread_info *thread = current_thread_info();
-	struct task_struct *tsk = thread->task;
+	struct task_struct *tsk = current;
 
 	if (!tsk_used_math(tsk)) {
 		local_irq_enable();
@@ -622,9 +599,17 @@ asmlinkage void math_state_restore(void)
 		local_irq_disable();
 	}
 
-	clts();				/* Allow maths ops (or we recurse) */
+	__thread_fpu_begin(tsk);
+	/*
+	 * Paranoid restore. send a SIGSEGV if we fail to restore the state.
+	 */
+	if (unlikely(restore_fpu_checking(tsk))) {
+		__thread_fpu_end(tsk);
+		force_sig(SIGSEGV, tsk);
+		return;
+	}
 
-	__math_state_restore();
+	tsk->fpu_counter++;
 }
 EXPORT_SYMBOL_GPL(math_state_restore);