ARC: irqflags - Interrupt enabling/disabling at in-core intc
ARC700 has an in-core intc which provides 2 priorities (a.k.a.) "levels"
of interrupts (per IRQ) hencforth referred to as L1/L2 interrupts.
CPU flags register STATUS32 has Interrupt Enable bits per level (E1/E2)
to globally enable (or disable) all IRQs at a level. Hence the
implementation of arch_local_irq_{save,restore,enable,disable}( )
The STATUS32 reg can be r/w only using the AUX Interface of ARC, hence
the use of LR/SR instructions. Further, E1/E2 bits in there can only be
updated using the FLAG insn.
The intc supports 32 interrupts - and per IRQ enabling is controlled by
a bit in the AUX_IENABLE register, hence the implmentation of
arch_{,un}mask_irq( ) routines.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/arc/include/asm/irqflags.h b/arch/arc/include/asm/irqflags.h
new file mode 100644
index 0000000..5cc1080
--- /dev/null
+++ b/arch/arc/include/asm/irqflags.h
@@ -0,0 +1,149 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __ASM_ARC_IRQFLAGS_H
+#define __ASM_ARC_IRQFLAGS_H
+
+/* vineetg: March 2010 : local_irq_save( ) optimisation
+ * -Remove explicit mov of current status32 into reg, that is not needed
+ * -Use BIC insn instead of INVERTED + AND
+ * -Conditionally disable interrupts (if they are not enabled, don't disable)
+*/
+
+#ifdef __KERNEL__
+
+#include <asm/arcregs.h>
+
+#ifndef __ASSEMBLY__
+
+/******************************************************************
+ * IRQ Control Macros
+ ******************************************************************/
+
+/*
+ * Save IRQ state and disable IRQs
+ */
+static inline long arch_local_irq_save(void)
+{
+ unsigned long temp, flags;
+
+ __asm__ __volatile__(
+ " lr %1, [status32] \n"
+ " bic %0, %1, %2 \n"
+ " and.f 0, %1, %2 \n"
+ " flag.nz %0 \n"
+ : "=r"(temp), "=r"(flags)
+ : "n"((STATUS_E1_MASK | STATUS_E2_MASK))
+ : "cc");
+
+ return flags;
+}
+
+/*
+ * restore saved IRQ state
+ */
+static inline void arch_local_irq_restore(unsigned long flags)
+{
+
+ __asm__ __volatile__(
+ " flag %0 \n"
+ :
+ : "r"(flags));
+}
+
+/*
+ * Unconditionally Enable IRQs
+ */
+extern void arch_local_irq_enable(void);
+
+/*
+ * Unconditionally Disable IRQs
+ */
+static inline void arch_local_irq_disable(void)
+{
+ unsigned long temp;
+
+ __asm__ __volatile__(
+ " lr %0, [status32] \n"
+ " and %0, %0, %1 \n"
+ " flag %0 \n"
+ : "=&r"(temp)
+ : "n"(~(STATUS_E1_MASK | STATUS_E2_MASK)));
+}
+
+/*
+ * save IRQ state
+ */
+static inline long arch_local_save_flags(void)
+{
+ unsigned long temp;
+
+ __asm__ __volatile__(
+ " lr %0, [status32] \n"
+ : "=&r"(temp));
+
+ return temp;
+}
+
+/*
+ * Query IRQ state
+ */
+static inline int arch_irqs_disabled_flags(unsigned long flags)
+{
+ return !(flags & (STATUS_E1_MASK));
+}
+
+static inline int arch_irqs_disabled(void)
+{
+ return arch_irqs_disabled_flags(arch_local_save_flags());
+}
+
+static inline void arch_mask_irq(unsigned int irq)
+{
+ unsigned int ienb;
+
+ ienb = read_aux_reg(AUX_IENABLE);
+ ienb &= ~(1 << irq);
+ write_aux_reg(AUX_IENABLE, ienb);
+}
+
+static inline void arch_unmask_irq(unsigned int irq)
+{
+ unsigned int ienb;
+
+ ienb = read_aux_reg(AUX_IENABLE);
+ ienb |= (1 << irq);
+ write_aux_reg(AUX_IENABLE, ienb);
+}
+
+#else
+
+.macro IRQ_DISABLE scratch
+ lr \scratch, [status32]
+ bic \scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK)
+ flag \scratch
+.endm
+
+.macro IRQ_DISABLE_SAVE scratch, save
+ lr \scratch, [status32]
+ mov \save, \scratch /* Make a copy */
+ bic \scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK)
+ flag \scratch
+.endm
+
+.macro IRQ_ENABLE scratch
+ lr \scratch, [status32]
+ or \scratch, \scratch, (STATUS_E1_MASK | STATUS_E2_MASK)
+ flag \scratch
+.endm
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* KERNEL */
+
+#endif