Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 217 insertions, 0 deletions

diff --git a/include/asm-mips/hazards.h b/include/asm-mips/hazards.h
new file mode 100644
index 0000000..f524eac
--- /dev/null
+++ b/include/asm-mips/hazards.h
@@ -0,0 +1,217 @@
+/*
+ * 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) 2003, 2004 Ralf Baechle
+ */
+#ifndef _ASM_HAZARDS_H
+#define _ASM_HAZARDS_H
+
+#include <linux/config.h>
+
+#ifdef __ASSEMBLY__
+
+	.macro	_ssnop
+	sll	$0, $0, 1
+	.endm
+
+	.macro	_ehb
+	sll	$0, $0, 3
+	.endm
+
+/*
+ * RM9000 hazards.  When the JTLB is updated by tlbwi or tlbwr, a subsequent
+ * use of the JTLB for instructions should not occur for 4 cpu cycles and use
+ * for data translations should not occur for 3 cpu cycles.
+ */
+#ifdef CONFIG_CPU_RM9000
+
+	.macro	mtc0_tlbw_hazard
+	.set	push
+	.set	mips32
+	_ssnop; _ssnop; _ssnop; _ssnop
+	.set	pop
+	.endm
+
+	.macro	tlbw_eret_hazard
+	.set	push
+	.set	mips32
+	_ssnop; _ssnop; _ssnop; _ssnop
+	.set	pop
+	.endm
+
+#else
+
+/*
+ * The taken branch will result in a two cycle penalty for the two killed
+ * instructions on R4000 / R4400.  Other processors only have a single cycle
+ * hazard so this is nice trick to have an optimal code for a range of
+ * processors.
+ */
+	.macro	mtc0_tlbw_hazard
+	b	. + 8
+	.endm
+
+	.macro	tlbw_eret_hazard
+	.endm
+#endif
+
+/*
+ * mtc0->mfc0 hazard
+ * The 24K has a 2 cycle mtc0/mfc0 execution hazard.
+ * It is a MIPS32R2 processor so ehb will clear the hazard.
+ */
+
+#ifdef CONFIG_CPU_MIPSR2
+/*
+ * Use a macro for ehb unless explicit support for MIPSR2 is enabled
+ */
+
+#define irq_enable_hazard
+	_ehb
+
+#define irq_disable_hazard
+	_ehb
+
+#elif defined(CONFIG_CPU_R10000) || defined(CONFIG_CPU_RM9000)
+
+/*
+ * R10000 rocks - all hazards handled in hardware, so this becomes a nobrainer.
+ */
+
+#define irq_enable_hazard
+
+#define irq_disable_hazard
+
+#else
+
+/*
+ * Classic MIPS needs 1 - 3 nops or ssnops
+ */
+#define irq_enable_hazard
+#define irq_disable_hazard						\
+	_ssnop; _ssnop; _ssnop
+
+#endif
+
+#else /* __ASSEMBLY__ */
+
+__asm__(
+	"	.macro	_ssnop					\n\t"
+	"	sll	$0, $2, 1				\n\t"
+	"	.endm						\n\t"
+	"							\n\t"
+	"	.macro	_ehb					\n\t"
+	"	sll	$0, $0, 3				\n\t"
+	"	.endm						\n\t");
+
+#ifdef CONFIG_CPU_RM9000
+/*
+ * RM9000 hazards.  When the JTLB is updated by tlbwi or tlbwr, a subsequent
+ * use of the JTLB for instructions should not occur for 4 cpu cycles and use
+ * for data translations should not occur for 3 cpu cycles.
+ */
+
+#define mtc0_tlbw_hazard()						\
+	__asm__ __volatile__(						\
+		".set\tmips32\n\t"					\
+		"_ssnop; _ssnop; _ssnop; _ssnop\n\t"			\
+		".set\tmips0")
+
+#define tlbw_use_hazard()						\
+	__asm__ __volatile__(						\
+		".set\tmips32\n\t"					\
+		"_ssnop; _ssnop; _ssnop; _ssnop\n\t"			\
+		".set\tmips0")
+#else
+
+/*
+ * Overkill warning ...
+ */
+#define mtc0_tlbw_hazard()						\
+	__asm__ __volatile__(						\
+		".set noreorder\n\t"					\
+		"nop; nop; nop; nop; nop; nop;\n\t"			\
+		".set reorder\n\t")
+
+#define tlbw_use_hazard()						\
+	__asm__ __volatile__(						\
+		".set noreorder\n\t"					\
+		"nop; nop; nop; nop; nop; nop;\n\t"			\
+		".set reorder\n\t")
+
+#endif
+
+/*
+ * mtc0->mfc0 hazard
+ * The 24K has a 2 cycle mtc0/mfc0 execution hazard.
+ * It is a MIPS32R2 processor so ehb will clear the hazard.
+ */
+
+#ifdef CONFIG_CPU_MIPSR2
+/*
+ * Use a macro for ehb unless explicit support for MIPSR2 is enabled
+ */
+__asm__(
+	"	.macro\tirq_enable_hazard			\n\t"
+	"	_ehb						\n\t"
+	"	.endm						\n\t"
+	"							\n\t"
+	"	.macro\tirq_disable_hazard			\n\t"
+	"	_ehb						\n\t"
+	"	.endm");
+
+#define irq_enable_hazard()						\
+	__asm__ __volatile__(						\
+	"_ehb\t\t\t\t# irq_enable_hazard")
+
+#define irq_disable_hazard()						\
+	__asm__ __volatile__(						\
+	"_ehb\t\t\t\t# irq_disable_hazard")
+
+#elif defined(CONFIG_CPU_R10000) || defined(CONFIG_CPU_RM9000)
+
+/*
+ * R10000 rocks - all hazards handled in hardware, so this becomes a nobrainer.
+ */
+
+__asm__(
+	"	.macro\tirq_enable_hazard			\n\t"
+	"	.endm						\n\t"
+	"							\n\t"
+	"	.macro\tirq_disable_hazard			\n\t"
+	"	.endm");
+
+#define irq_enable_hazard()	do { } while (0)
+#define irq_disable_hazard()	do { } while (0)
+
+#else
+
+/*
+ * Default for classic MIPS processors.  Assume worst case hazards but don't
+ * care about the irq_enable_hazard - sooner or later the hardware will
+ * enable it and we don't care when exactly.
+ */
+
+__asm__(
+	"	#						\n\t"
+	"	# There is a hazard but we do not care		\n\t"
+	"	#						\n\t"
+	"	.macro\tirq_enable_hazard			\n\t"
+	"	.endm						\n\t"
+	"							\n\t"
+	"	.macro\tirq_disable_hazard			\n\t"
+	"	_ssnop; _ssnop; _ssnop				\n\t"
+	"	.endm");
+
+#define irq_enable_hazard()	do { } while (0)
+#define irq_disable_hazard()						\
+	__asm__ __volatile__(						\
+	"_ssnop; _ssnop; _ssnop;\t\t# irq_disable_hazard")
+
+#endif
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_HAZARDS_H */