File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/mips/lib/mips-atomic.c b/arch/mips/lib/mips-atomic.c
new file mode 100644
index 0000000..272af8a
--- /dev/null
+++ b/arch/mips/lib/mips-atomic.c
@@ -0,0 +1,141 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1994, 95, 96, 97, 98, 99, 2003 by Ralf Baechle
+ * Copyright (C) 1996 by Paul M. Antoine
+ * Copyright (C) 1999 Silicon Graphics
+ * Copyright (C) 2000 MIPS Technologies, Inc.
+ */
+#include <asm/irqflags.h>
+#include <asm/hazards.h>
+#include <linux/compiler.h>
+#include <linux/preempt.h>
+#include <linux/export.h>
+#include <linux/stringify.h>
+
+#if !defined(CONFIG_CPU_MIPSR2) && !defined(CONFIG_CPU_MIPSR6)
+
+/*
+ * For cli() we have to insert nops to make sure that the new value
+ * has actually arrived in the status register before the end of this
+ * macro.
+ * R4000/R4400 need three nops, the R4600 two nops and the R10000 needs
+ * no nops at all.
+ */
+/*
+ * For TX49, operating only IE bit is not enough.
+ *
+ * If mfc0 $12 follows store and the mfc0 is last instruction of a
+ * page and fetching the next instruction causes TLB miss, the result
+ * of the mfc0 might wrongly contain EXL bit.
+ *
+ * ERT-TX49H2-027, ERT-TX49H3-012, ERT-TX49HL3-006, ERT-TX49H4-008
+ *
+ * Workaround: mask EXL bit of the result or place a nop before mfc0.
+ */
+notrace void arch_local_irq_disable(void)
+{
+ preempt_disable();
+
+ __asm__ __volatile__(
+ " .set push \n"
+ " .set noat \n"
+ " mfc0 $1,$12 \n"
+ " ori $1,0x1f \n"
+ " xori $1,0x1f \n"
+ " .set noreorder \n"
+ " mtc0 $1,$12 \n"
+ " " __stringify(__irq_disable_hazard) " \n"
+ " .set pop \n"
+ : /* no outputs */
+ : /* no inputs */
+ : "memory");
+
+ preempt_enable();
+}
+EXPORT_SYMBOL(arch_local_irq_disable);
+
+
+notrace unsigned long arch_local_irq_save(void)
+{
+ unsigned long flags;
+
+ preempt_disable();
+
+ __asm__ __volatile__(
+ " .set push \n"
+ " .set reorder \n"
+ " .set noat \n"
+ " mfc0 %[flags], $12 \n"
+ " ori $1, %[flags], 0x1f \n"
+ " xori $1, 0x1f \n"
+ " .set noreorder \n"
+ " mtc0 $1, $12 \n"
+ " " __stringify(__irq_disable_hazard) " \n"
+ " .set pop \n"
+ : [flags] "=r" (flags)
+ : /* no inputs */
+ : "memory");
+
+ preempt_enable();
+
+ return flags;
+}
+EXPORT_SYMBOL(arch_local_irq_save);
+
+notrace void arch_local_irq_restore(unsigned long flags)
+{
+ unsigned long __tmp1;
+
+ preempt_disable();
+
+ __asm__ __volatile__(
+ " .set push \n"
+ " .set noreorder \n"
+ " .set noat \n"
+ " mfc0 $1, $12 \n"
+ " andi %[flags], 1 \n"
+ " ori $1, 0x1f \n"
+ " xori $1, 0x1f \n"
+ " or %[flags], $1 \n"
+ " mtc0 %[flags], $12 \n"
+ " " __stringify(__irq_disable_hazard) " \n"
+ " .set pop \n"
+ : [flags] "=r" (__tmp1)
+ : "0" (flags)
+ : "memory");
+
+ preempt_enable();
+}
+EXPORT_SYMBOL(arch_local_irq_restore);
+
+
+notrace void __arch_local_irq_restore(unsigned long flags)
+{
+ unsigned long __tmp1;
+
+ preempt_disable();
+
+ __asm__ __volatile__(
+ " .set push \n"
+ " .set noreorder \n"
+ " .set noat \n"
+ " mfc0 $1, $12 \n"
+ " andi %[flags], 1 \n"
+ " ori $1, 0x1f \n"
+ " xori $1, 0x1f \n"
+ " or %[flags], $1 \n"
+ " mtc0 %[flags], $12 \n"
+ " " __stringify(__irq_disable_hazard) " \n"
+ " .set pop \n"
+ : [flags] "=r" (__tmp1)
+ : "0" (flags)
+ : "memory");
+
+ preempt_enable();
+}
+EXPORT_SYMBOL(__arch_local_irq_restore);
+
+#endif /* !CONFIG_CPU_MIPSR2 */