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Diffstat (limited to 'arch/powerpc/lib/vmx-helper.c')
-rw-r--r--arch/powerpc/lib/vmx-helper.c27
1 files changed, 12 insertions, 15 deletions
diff --git a/arch/powerpc/lib/vmx-helper.c b/arch/powerpc/lib/vmx-helper.c
index 9f340494a8ac..54340912398f 100644
--- a/arch/powerpc/lib/vmx-helper.c
+++ b/arch/powerpc/lib/vmx-helper.c
@@ -1,17 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/*
- * 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
*
@@ -21,7 +9,6 @@
#include <linux/uaccess.h>
#include <linux/hardirq.h>
#include <asm/switch_to.h>
-#include <asm/asm-prototypes.h>
int enter_vmx_usercopy(void)
{
@@ -49,7 +36,17 @@ int exit_vmx_usercopy(void)
{
disable_kernel_altivec();
pagefault_enable();
- preempt_enable();
+ preempt_enable_no_resched();
+ /*
+ * Must never explicitly call schedule (including preempt_enable())
+ * while in a kuap-unlocked user copy, because the AMR register will
+ * not be saved and restored across context switch. However preempt
+ * kernels need to be preempted as soon as possible if need_resched is
+ * set and we are preemptible. The hack here is to schedule a
+ * decrementer to fire here and reschedule for us if necessary.
+ */
+ if (need_irq_preemption() && need_resched())
+ set_dec(1);
return 0;
}