Merge branch 'x86/platform' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into stable/for-linus-3.7

* 'x86/platform' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (9690 commits)
  x86: Document x86_init.paging.pagetable_init()
  x86: xen: Cleanup and remove x86_init.paging.pagetable_setup_done()
  x86: Move paging_init() call to x86_init.paging.pagetable_init()
  x86: Rename pagetable_setup_start() to pagetable_init()
  x86: Remove base argument from x86_init.paging.pagetable_setup_start
  Linux 3.6-rc5
  HID: tpkbd: work even if the new Lenovo Keyboard driver is not configured
  Remove user-triggerable BUG from mpol_to_str
  xen/pciback: Fix proper FLR steps.
  uml: fix compile error in deliver_alarm()
  dj: memory scribble in logi_dj
  Fix order of arguments to compat_put_time[spec|val]
  xen: Use correct masking in xen_swiotlb_alloc_coherent.
  xen: fix logical error in tlb flushing
  xen/p2m: Fix one-off error in checking the P2M tree directory.
  powerpc: Don't use __put_user() in patch_instruction
  powerpc: Make sure IPI handlers see data written by IPI senders
  powerpc: Restore correct DSCR in context switch
  powerpc: Fix DSCR inheritance in copy_thread()
  powerpc: Keep thread.dscr and thread.dscr_inherit in sync
  ...

1 files changed, 74 insertions, 0 deletions

diff --git a/arch/powerpc/lib/vmx-helper.c b/arch/powerpc/lib/vmx-helper.c
new file mode 100644
index 000000000000..3cf529ceec5b
--- /dev/null
+++ b/arch/powerpc/lib/vmx-helper.c
@@ -0,0 +1,74 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright (C) IBM Corporation, 2011
+ *
+ * Authors: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
+ *          Anton Blanchard <anton@au.ibm.com>
+ */
+#include <linux/uaccess.h>
+#include <linux/hardirq.h>
+#include <asm/switch_to.h>
+
+int enter_vmx_usercopy(void)
+{
+	if (in_interrupt())
+		return 0;
+
+	/* This acts as preempt_disable() as well and will make
+	 * enable_kernel_altivec(). We need to disable page faults
+	 * as they can call schedule and thus make us lose the VMX
+	 * context. So on page faults, we just fail which will cause
+	 * a fallback to the normal non-vmx copy.
+	 */
+	pagefault_disable();
+
+	enable_kernel_altivec();
+
+	return 1;
+}
+
+/*
+ * This function must return 0 because we tail call optimise when calling
+ * from __copy_tofrom_user_power7 which returns 0 on success.
+ */
+int exit_vmx_usercopy(void)
+{
+	pagefault_enable();
+	return 0;
+}
+
+int enter_vmx_copy(void)
+{
+	if (in_interrupt())
+		return 0;
+
+	preempt_disable();
+
+	enable_kernel_altivec();
+
+	return 1;
+}
+
+/*
+ * All calls to this function will be optimised into tail calls. We are
+ * passed a pointer to the destination which we return as required by a
+ * memcpy implementation.
+ */
+void *exit_vmx_copy(void *dest)
+{
+	preempt_enable();
+	return dest;
+}