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-rw-r--r--arch/mips/lib/mips-atomic.c176
1 files changed, 176 insertions, 0 deletions
diff --git a/arch/mips/lib/mips-atomic.c b/arch/mips/lib/mips-atomic.c
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+++ b/arch/mips/lib/mips-atomic.c
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+/*
+ * 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>
+
+#if !defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_MIPS_MT_SMTC)
+
+/*
+ * 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 arch_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)
+ /* see irqflags.h for inline function */
+#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");
+
+void arch_local_irq_disable(void)
+{
+ preempt_disable();
+ __asm__ __volatile__(
+ "arch_local_irq_disable"
+ : /* no outputs */
+ : /* no inputs */
+ : "memory");
+ preempt_enable();
+}
+EXPORT_SYMBOL(arch_local_irq_disable);
+
+
+__asm__(
+ " .macro arch_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)
+ /* see irqflags.h for inline function */
+#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");
+
+unsigned long arch_local_irq_save(void)
+{
+ unsigned long flags;
+ preempt_disable();
+ asm volatile("arch_local_irq_save\t%0"
+ : "=r" (flags)
+ : /* no inputs */
+ : "memory");
+ preempt_enable();
+ return flags;
+}
+EXPORT_SYMBOL(arch_local_irq_save);
+
+
+__asm__(
+ " .macro arch_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)
+ /* see irqflags.h for inline function */
+#elif defined(CONFIG_CPU_MIPSR2)
+ /* see irqflags.h for inline function */
+#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");
+
+void arch_local_irq_restore(unsigned long flags)
+{
+ unsigned long __tmp1;
+
+#ifdef CONFIG_MIPS_MT_SMTC
+ /*
+ * SMTC kernel needs to do a software replay of queued
+ * IPIs, at the cost of branch and call overhead on each
+ * local_irq_restore()
+ */
+ if (unlikely(!(flags & 0x0400)))
+ smtc_ipi_replay();
+#endif
+ preempt_disable();
+ __asm__ __volatile__(
+ "arch_local_irq_restore\t%0"
+ : "=r" (__tmp1)
+ : "0" (flags)
+ : "memory");
+ preempt_enable();
+}
+EXPORT_SYMBOL(arch_local_irq_restore);
+
+
+void __arch_local_irq_restore(unsigned long flags)
+{
+ unsigned long __tmp1;
+
+ preempt_disable();
+ __asm__ __volatile__(
+ "arch_local_irq_restore\t%0"
+ : "=r" (__tmp1)
+ : "0" (flags)
+ : "memory");
+ preempt_enable();
+}
+EXPORT_SYMBOL(__arch_local_irq_restore);
+
+#endif /* !defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_MIPS_MT_SMTC) */
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