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authorPaul Mundt <lethal@linux-sh.org>2012-01-09 11:12:55 +0900
committerPaul Mundt <lethal@linux-sh.org>2012-01-09 11:12:55 +0900
commitca371d2854d48c0c22e7aa031df182f96dc85820 (patch)
tree1c62be8b4da0bfc82fa7ffa1ad5b0e958266cbd1 /arch/powerpc/lib/copyuser_power7_vmx.c
parent0d376945d0bc0a8f8e00861d506b10e42e8af372 (diff)
parenta0e86bd4252519321b0d102dc4ed90557aa7bee9 (diff)
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux into sh-latest
Conflicts: arch/arm/mach-shmobile/clock-sh73a0.c Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/powerpc/lib/copyuser_power7_vmx.c')
-rw-r--r--arch/powerpc/lib/copyuser_power7_vmx.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/arch/powerpc/lib/copyuser_power7_vmx.c b/arch/powerpc/lib/copyuser_power7_vmx.c
new file mode 100644
index 000000000000..6e1efadac48b
--- /dev/null
+++ b/arch/powerpc/lib/copyuser_power7_vmx.c
@@ -0,0 +1,50 @@
+/*
+ * 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>
+
+int enter_vmx_copy(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_copy(void)
+{
+ pagefault_enable();
+ return 0;
+}