Linux-2.6.12-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!
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 */