[MIPS] TRACE_IRQFLAGS_SUPPORT support.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 225 insertions, 0 deletions

diff --git a/include/asm-mips/irqflags.h b/include/asm-mips/irqflags.h
new file mode 100644
index 000000000000..43ca09a3a3d0
--- /dev/null
+++ b/include/asm-mips/irqflags.h
@@ -0,0 +1,225 @@
+/*
+ * 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.
+ */
+#ifndef _ASM_IRQFLAGS_H
+#define _ASM_IRQFLAGS_H
+
+#ifndef __ASSEMBLY__
+
+#include <asm/hazards.h>
+
+__asm__ (
+	"	.macro	raw_local_irq_enable				\n"
+	"	.set	push						\n"
+	"	.set	reorder						\n"
+	"	.set	noat						\n"
+#ifdef CONFIG_MIPS_MT_SMTC
+	"	mfc0	$1, $2, 1	# SMTC - clear TCStatus.IXMT	\n"
+	"	ori	$1, 0x400					\n"
+	"	xori	$1, 0x400					\n"
+	"	mtc0	$1, $2, 1					\n"
+#elif defined(CONFIG_CPU_MIPSR2)
+	"	ei							\n"
+#else
+	"	mfc0	$1,$12						\n"
+	"	ori	$1,0x1f						\n"
+	"	xori	$1,0x1e						\n"
+	"	mtc0	$1,$12						\n"
+#endif
+	"	irq_enable_hazard					\n"
+	"	.set	pop						\n"
+	"	.endm");
+
+static inline void raw_local_irq_enable(void)
+{
+	__asm__ __volatile__(
+		"raw_local_irq_enable"
+		: /* no outputs */
+		: /* no inputs */
+		: "memory");
+}
+
+/*
+ * 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.
+ */
+__asm__ (
+	"	.macro	raw_local_irq_disable\n"
+	"	.set	push						\n"
+	"	.set	noat						\n"
+#ifdef CONFIG_MIPS_MT_SMTC
+	"	mfc0	$1, $2, 1					\n"
+	"	ori	$1, 0x400					\n"
+	"	.set	noreorder					\n"
+	"	mtc0	$1, $2, 1					\n"
+#elif defined(CONFIG_CPU_MIPSR2)
+	"	di							\n"
+#else
+	"	mfc0	$1,$12						\n"
+	"	ori	$1,0x1f						\n"
+	"	xori	$1,0x1f						\n"
+	"	.set	noreorder					\n"
+	"	mtc0	$1,$12						\n"
+#endif
+	"	irq_disable_hazard					\n"
+	"	.set	pop						\n"
+	"	.endm							\n");
+
+static inline void raw_local_irq_disable(void)
+{
+	__asm__ __volatile__(
+		"raw_local_irq_disable"
+		: /* no outputs */
+		: /* no inputs */
+		: "memory");
+}
+
+__asm__ (
+	"	.macro	raw_local_save_flags flags			\n"
+	"	.set	push						\n"
+	"	.set	reorder						\n"
+#ifdef CONFIG_MIPS_MT_SMTC
+	"	mfc0	\\flags, $2, 1					\n"
+#else
+	"	mfc0	\\flags, $12					\n"
+#endif
+	"	.set	pop						\n"
+	"	.endm							\n");
+
+#define raw_local_save_flags(x)						\
+__asm__ __volatile__(							\
+	"raw_local_save_flags %0"					\
+	: "=r" (x))
+
+__asm__ (
+	"	.macro	raw_local_irq_save result			\n"
+	"	.set	push						\n"
+	"	.set	reorder						\n"
+	"	.set	noat						\n"
+#ifdef CONFIG_MIPS_MT_SMTC
+	"	mfc0	\\result, $2, 1					\n"
+	"	ori	$1, \\result, 0x400				\n"
+	"	.set	noreorder					\n"
+	"	mtc0	$1, $2, 1					\n"
+	"	andi	\\result, \\result, 0x400			\n"
+#elif defined(CONFIG_CPU_MIPSR2)
+	"	di	\\result					\n"
+	"	andi	\\result, 1					\n"
+#else
+	"	mfc0	\\result, $12					\n"
+	"	ori	$1, \\result, 0x1f				\n"
+	"	xori	$1, 0x1f					\n"
+	"	.set	noreorder					\n"
+	"	mtc0	$1, $12						\n"
+#endif
+	"	irq_disable_hazard					\n"
+	"	.set	pop						\n"
+	"	.endm							\n");
+
+#define raw_local_irq_save(x)						\
+__asm__ __volatile__(							\
+	"raw_local_irq_save\t%0"					\
+	: "=r" (x)							\
+	: /* no inputs */						\
+	: "memory")
+
+__asm__ (
+	"	.macro	raw_local_irq_restore flags			\n"
+	"	.set	push						\n"
+	"	.set	noreorder					\n"
+	"	.set	noat						\n"
+#ifdef CONFIG_MIPS_MT_SMTC
+	"mfc0	$1, $2, 1						\n"
+	"andi	\\flags, 0x400						\n"
+	"ori	$1, 0x400						\n"
+	"xori	$1, 0x400						\n"
+	"or	\\flags, $1						\n"
+	"mtc0	\\flags, $2, 1						\n"
+#elif defined(CONFIG_CPU_MIPSR2) && defined(CONFIG_IRQ_CPU)
+	/*
+	 * Slow, but doesn't suffer from a relativly unlikely race
+	 * condition we're having since days 1.
+	 */
+	"	beqz	\\flags, 1f					\n"
+	"	 di							\n"
+	"	ei							\n"
+	"1:								\n"
+#elif defined(CONFIG_CPU_MIPSR2)
+	/*
+	 * Fast, dangerous.  Life is fun, life is good.
+	 */
+	"	mfc0	$1, $12						\n"
+	"	ins	$1, \\flags, 0, 1				\n"
+	"	mtc0	$1, $12						\n"
+#else
+	"	mfc0	$1, $12						\n"
+	"	andi	\\flags, 1					\n"
+	"	ori	$1, 0x1f					\n"
+	"	xori	$1, 0x1f					\n"
+	"	or	\\flags, $1					\n"
+	"	mtc0	\\flags, $12					\n"
+#endif
+	"	irq_disable_hazard					\n"
+	"	.set	pop						\n"
+	"	.endm							\n");
+
+#define raw_local_irq_restore(flags)					\
+do {									\
+	unsigned long __tmp1;						\
+									\
+	__asm__ __volatile__(						\
+		"raw_local_irq_restore\t%0"				\
+		: "=r" (__tmp1)						\
+		: "0" (flags)						\
+		: "memory");						\
+} while(0)
+
+static inline int raw_irqs_disabled_flags(unsigned long flags)
+{
+#ifdef CONFIG_MIPS_MT_SMTC
+	/*
+	 * SMTC model uses TCStatus.IXMT to disable interrupts for a thread/CPU
+	 */
+	return flags & 0x400;
+#else
+	return !(flags & 1);
+#endif
+}
+
+#endif
+
+/*
+ * Do the CPU's IRQ-state tracing from assembly code.
+ */
+#ifdef CONFIG_TRACE_IRQFLAGS
+# define TRACE_IRQS_ON							\
+	jal	trace_hardirqs_on
+# define TRACE_IRQS_OFF							\
+	jal	trace_hardirqs_off
+#else
+# define TRACE_IRQS_ON
+# define TRACE_IRQS_OFF
+#endif
+
+#endif /* _ASM_IRQFLAGS_H */